WO2002088593A1

WO2002088593A1 - Gastight container

Info

Publication number: WO2002088593A1
Application number: PCT/CH2002/000229
Authority: WO
Inventors: Eva Maria Moser; Armin Reller
Original assignee: Eva Maria Moser; Armin Reller
Priority date: 2001-04-25
Filing date: 2002-04-25
Publication date: 2002-11-07
Also published as: CN1520500A; BR0209247A; CH695222A5; CA2445812A1; US20040149759A1; RU2003134013A; JP2004522104A; RU2298724C2; EP1384027A1

Abstract

The invention relates to a gastight, pressure-resistant storage and/or transport container (10) for low-molecular, reactive filling media, especially for hydrogen, oxygen, air, methane and/or methanol. Said container has a high filling pressure and is embodied in an essentially rotationally symmetric manner, having at least one connector cap (15) with a sealing device (16). The wall (12) of the container is essentially comprised of a thermoplastic synthetic material having at least one diffusion barrier (18, 19) system and/or a diffusion barrier and anti-corrosion system (18, 19). In order to offer protection for hydrogen and oxygen containers, the diffusion barrier system can be embodied in the form of at least one compact layer and/or can contain finely dispersed, distributed reactive nanoparticles (18) in the wall (12) of the container, in at least one composite film (28) and/or in at least one diffusion barrier layer (18).

Description

Gastight container

The invention relates to a gas-tight, pressure-resistant storage and / or transport container for low-molecular, reactive filling media, in particular for hydrogen, oxygen, air, methane and / or methanol, with a high filling pressure, which container is essentially rotationally symmetrical and has at least one connection cap has a closure device.

It has long been customary to fill, store and / or transport low-molecular, reactive media, in particular gases such as hydrogen, oxygen and air, in thick-walled metal bottles with a secured cap. In this way, large amounts of gas can be concentrated in a confined space and stored for long periods without loss and safely transported. A pressure reducing valve is placed on the cap of a metal bottle only before use.

Thick-walled metal bottles made of steel have the disadvantage that they are extremely heavy compared to the stored content. The replacement of steel bottles with appropriate aluminum bottles was a first important step in the right direction in terms of weight, but the above-mentioned mismatch between content and container continues to exist to a lesser extent.

US 4073400 A describes such a gas container made of a metal, preferably aluminum or steel, which has an outer protective layer made of a fiber-reinforced resin / polymer. Optionally, an anti-corrosion layer is also applied on the inside, which also consists of a fiber-reinforced resin / polymer. Of course, no diffusion protection is necessary with this metal container. DE 3821852 A1 also describes a pressurized gas bottle made of a metallic inner container and circumferential, glass fiber-reinforced plastic layers. This compressed gas bottle, intended as a propellant container for motor vehicles, is suitable for filling pressures up to 340 bar. Thanks to the metal bottle, there are no diffusion problems, and there are no corrosion problems when using a corrosion-resistant aluminum alloy for the inner container.

Since the oil crisis, natural gas has played an increasing role in both the heating and automotive sectors. The French company Ullit S.A., F-36400 La Chätre, offers ultra-light high-pressure bottles for natural gas vehicles, which essentially consist of a one-piece thermoplastic winding body. These bottles with a capacity of 126 liters and an operating pressure of 200 bar are installed in a vehicle using batteries and serve as a fuel reserve. Plastic bottles, including plastic composite bottles, are a completely new type of gas container in the high-pressure range compared to metal bottles. Plastic bottles have a very low weight, are not susceptible to corrosion, show no alternating load fatigue and are particularly suitable for higher molecular weight gases, e.g. Natural gases, sufficiently dense.

WO 00/66939 A1 describes the production of a two-layer gas pressure container made of plastic. An inner container made of plastic is pretreated in rotation to increase the wetting and adhesion properties. After applying an adhesive, a fiber-reinforced wrapping tape is applied in a spiral line, which sticks very well to the inner container and forms an effective pressure reinforcement. Diffusion or corrosion problems are not described or mentioned.

A double-walled heat storage bottle (thermos bottle) made of plastic with respect to a gas pressure container for high pressures according to US 3921844 A has in a known manner the heat radiation reflecting silver layers, which also act as diffusion barriers. The vacuum between the double walls with comparatively very thin walls can be maintained for a long time and heat convection prevented. In a pressure vessel, such a double wall with a vacuum in between would not only be nonsensical, but counterproductive.

The inventors have set themselves the task of creating a gas-tight, pressure-resistant storage and / or transport container of the type mentioned at the outset, which is media-specific impermeable and / or, if necessary, corrosion-resistant with a reduced weight.

The object is achieved according to the invention in that the container wall consists essentially of a thermoplastic with at least one diffusion barrier system or a diffusion barrier and corrosion protection system. Special and further developing embodiments of the container are the subject of dependent claims.

The term “diffusion barrier layer” encompasses layers deposited on the container wall as well as films placed on or into the container wall, with or without a functional layer / s. A diffusion barrier layer can also be a corrosion protection layer at the same time or exclusively, without this having to be done every time All types of diffusion barrier layers preferably have approximately the same expansion coefficient as the container wall.

A “diffusion barrier system” or a “corrosion protection system” can comprise a compact layer and / or dispersed, passive or reactive nanoparticles. Reactive nanoparticles react chemically with a permeating gas, passive nanoparticles adsorb (store) this.

Plastic containers with a high filling pressure, ie in the range of at least 50-100 bar, have the usual external dimensions and shapes. They are preferably essentially cylindrical and have a closure cap on one or both sides in the region of their longitudinal axis a closure of the usual type. The jacket length of large containers is expediently in the usual range from 1 to 6 m, the inside diameter is up to 40 cm, in particular about 35 cm, the filling pressure is preferably at least 150 bar, in particular at least 250 bar. The portable medical bottles for patients, which are also included in the invention, are designed to be substantially smaller.

The stability and the bursting pressure of the container can be increased significantly if the thermoplastic plastic of the container wall, which consists for example of polyethylene, polypropylene, acetylbutadiene styrene, polyamide, polyvinyl acetate or a polyester, is reinforced with a tensile material, preferably with carbon, Glass or ceramic fibers, but also with steel wires.

Depending on the aggressiveness and permeability of the filling medium and the outside atmosphere, a diffusion barrier layer is arranged inside and / or outside the container wall, possibly also or only in this wall itself.

- In the case of aggressive filling medium in a container stored in an inert atmosphere, only an internal diffusion barrier layer is necessary, or the wall of a hydrogen container contains dispersed, reactive nanoparticles.

- If a container with an aggressive filling medium is stored in a corrosive atmosphere, an external diffusion barrier layer is also applied, which is also a corrosion protection layer.

- In the case of a container wall that is inert to a reactive filling medium, a diffusion barrier layer can be integrated into this wall, for example by coextrusion or corresponding winding technology, both are known per se, or the wall of a hydrogen container contains dispersed, passive or reactive nanoparticles. At least one diffusion barrier layer can be applied to the container wall using two fundamentally different methods:

as a preferably 10 to 1000 μm thick composite film with a diffusion barrier layer in the narrower sense of preferably at most about 500 μm, in particular at most about 20 μm, thickness,

by deposition from the gas phase, with or without chemical reaction, also as a thin layer in the range from 10 to 600 nm, in particular up to 100 nm. This deposition can take place directly on the container wall and / or on a carrier film subsequently applied to or in the container wall ,

The outside film is applied, for example, by wrapping, preferably with a strong overlap of film strips applied in a spiral line, by longitudinally applying a film, again with a strong overlap of the side edges, or by applying a shrinking film or one that can be welded to size. The inner coating or inner lining with a film for the production of the diffusion barrier layer takes place by introducing a bag cut to size with the dimensions corresponding to the inside of the container, one or two openings being provided corresponding to the container. The inserted bag is fastened in the area of the filler neck, e.g. by gluing or clamping by screwing.

A metal foil, usually an aluminum or a steel foil, is applied or extruded as a diffusion barrier layer, preferably as a composite foil. A composite film made of a 9 μm thick aluminum foil with an LLDPE (low density polyethylene with a linear structure) laminated or extruded on one or two sides or extruded, for example about 100 μm thick, is sufficiently tear-resistant for all the methods mentioned.

Pure plastic composite films or multi-layers can also be applied or extruded, e.g. LLDPE (100 μm) / OPP (20 μm) / PVA (14 μm) / OPP (20 μm) LLDPE (100 μm). OPP is oriented polypropylene, PVA (= PVAL) polyvinyl alcohol. The PVA layer can also be provided with an SiO _x or DLC layer (Diamond Like Carbon).

A container according to the invention, or a film inserted therein, can also be protected with one or more diffusion barrier layers which are separated from the gas phase. The deposition from the gas phase takes place in a manner known per se with or without a chemical reaction in the gas phase, also as co-deposition of materials. Specific examples are vaporization with an arc (Are) and cathode sputtering (sputtering). Further examples are the deposition using lasers, electron, ion or molecular beams or thermal action, in each case with or without plasma excitation and with or without magnetic field support, and plasma spraying. The deposited layers form a diffusion barrier layer, which is also the corrosion protection layer where necessary.

If a plastic container according to the invention or a film to be applied or inserted is to have a metallic or ceramic diffusion barrier layer, pretreatment is often advantageous in order to increase the adhesion of this diffusion barrier layer. The pretreatment is expediently carried out with a plasma activation of the surface to be treated or with an extremely thin polar plasma layer of clearly <1 μm. In a first case, the coating is deposited immediately after activation, in a second case the polar layer can stabilize the surface tension of the plastic surface for years to> 50 mN / m or, if necessary, even to> 70 mN / m.

In the plasma activation for pretreatment, a radio frequency discharge (RF) in a mixture of noble gases (Ar, He), oxygen-containing and / or nitrogen-containing monomer gases is supplied, for example using CO _2l O ₂ , N ₂ , NO _x and / or NH ₃ , good results achieved. RF includes low frequency, radio frequency and maximum frequency. Plasma activation has long been used industrially, for example as a corona discharge or low-pressure discharge.

Examples: - Ar and a little O _{2 are} applied to a plastic substrate for less than 1 min, at 200 - 2000 W, 13.56 MHz or 2.45 GHz, continuously or pulsed. - NH ₃ containing noble gases is applied to a plastic substrate for less than 1 min, with high or low frequency discharge. Very good results are obtained for the adhesion of AI to polypropylene.

In the case of a plasma coating as a pretreatment, mixtures of the noble gases Ar and He and / or, depending on the surface tension to be achieved, mixtures, e.g. B. from the monomer gases CO ₂ , O ₂ , N ₂ , NO _x , NH ₃ , CH ₃ OH, CH ₄ , CH ₃ CN and C ₂ H ₂₎ . For long-term stable hydrophilic printing layers, reference is made to WO 99/39842, according to which an anhydrous process gas is used for a polar coating, each containing at least one also substituted hydrocarbon compound with up to eight C atoms and one inorganic gas.

Example: A plasma coating as a pretreatment is carried out with a mixture of equal parts of: Ar, C ₂ H ₂ , NO ₂ and CO ₂ . This results in a surface tension of> 60 mN / m.

An apolar diffusion barrier layer, ie with a barrier effect, can also be applied directly, ie without pretreatment, by means of plasma polymerization, for example as a 0.01 to 1 μm thick amorphous DLC hydrocarbon layer (diamond-like carbon). This is based on carbon and hydrogen, has a content of 20 to 80 at% each of the two elements, and 0.01 to 6 at% each of at least one element of the group consisting of oxygen, nitrogen, fluorine, Contains chlorine, bromine, boron and silicon. Diesbezüg- reference is made to WO 00/32938 (table, item E).

Following the pretreatment described above, an actual diffusion barrier layer, e.g. B. deposited a metallic, organic metal-containing and / or ceramic layer. For the purposes of the present invention, the metallic layers also include boron and silicon. There are several methods and combinations thereof known per se to choose from. Most are suitable for coating the outside of the container, but only to a limited extent for coating the inside. At most, technical details have to be adapted, such as the enlargement of the mouth and / or the miniaturization of the source.

For the deposition of a submicron-thick diffusion barrier layer on the container wall or on a film to be applied or applied, the use of the plasma-supported coating processes is particularly suitable because the substrate temperature can be kept lower and good adhesion of the layer to the substrate through an adhesion-promoting interaction the plasma is reached. In addition, a targeted variation of the plasma parameters, including the process gases, results in a layer structure that adequately copes with the respective expansions of the container.

Effective ceramic diffusion barrier layers consist, for example, of Al ₂ O ₃₎ TiN, TiC, Si ₃ N ₄ , SiC, ZrO ₂ , Cr ₂ O ₃ , SiO _x and / or SiO _x Ny.

A diffusion barrier system according to the invention comprises, according to a variant for a hydrogen container in the container wall, in the diffusion barrier layer and / or in a composite film with the diffusion barrier layer, finely dispersed passive nanoparticles for storing hydrogen or reactive nanoparticles for chemical reaction with hydrogen. These nanoparticles preferably contain Ti, Pd, Fe, Al, Mg, Mg ₂ Ni, TiC, TiO ₂ , Ti ₃ Al, TiN, Ti ₂ Ni, LaNi ₅ H ₆ , graphite, silicates and / or carbon-containing nanotubes. The nano Particles can also be embedded in a matrix, for example passive TiN nanoparticles or active Ti nanoparticles in an Si ₃ N matrix with a grain size of at most a few μm. Analogously, Ti and / or TiC nanoparticles can be embedded in an SiC matrix, or Ti and / or TiO ₂ nanoparticles in an SiO ₂ matrix. For other reactive gases, eg oxygen, there are analog diffusion barrier systems (table, item I).

Reactive nanoparticles react chemically with a gas that diffuses through the container wall, eg Al nanoparticles with oxygen to form Al ₂ O ₃ . Passive, ie non-reactive nanoparticles adsorb a gas diffusing through the container wall, eg Ti nanoparticles H ₂ . They can be installed in a wide variety of geometric shapes and form a physical diffusion barrier.

A hydrogen-storing component must be selected so that the expansion coefficient for hydrogen absorption and the particle size are matched to the container mass and pressure variations.

Examples of systems of diffusion barrier layers:

- Functional layer system 1: container and film, barrier layer inside and / or outside

There is a plasma activation of a plastic substrate in order to increase the adhesion to the following coating. A metallic aluminum layer is applied by PVD (Physical Vapor Deposition). The

PVD is carried out, for example, by cathode sputtering and / or arc evaporation inside and outside, thermal and electron beam evaporation outside. If this metal layer is subsequently oxidized using a plasma process, for example by means of RF discharge, a defined additional Al ₂ O ₃ protective and diffusion barrier layer forms on the

Surface. This is e.g. B. essential for a methanol container if no further protective layer is deposited on the inside. Functional layer system 2: container or container with film, barrier layer preferably inside

A DLC layer is deposited directly, without pretreatment, as a diffusion barrier layer, which also acts as a protective layer, on a plastic substrate. In order to achieve the necessary flexibility, a gradient layer from polymer-like to diamond-like or from elastic to dense is produced via the process control. The electrically non-conductive substrate with the layer material enables inductive coupling of the radio frequency into the container.

Separately or in addition to at least one barrier layer, metal-containing nanoparticles (eg Al, Ti, Mg) can be deposited finely dispersed on / into the container wall or in a film to be introduced via the gas phase with organometallic components, which absorb the diffusing hydrogen or oxygen and / or save.

Functional layer system 3: container and film, barrier layer inside (arc, sputtering) and / or outside (arc / sputtering / PA reactive electron beam evaporation).

A plastic substrate is plasma pretreated to smooth the surface if necessary and to increase the adhesion to the subsequent coating. A ceramic layer made of Al ₂ O ₃ , SiO _x , SiON, TiO ₂ and / or

ZrO ₂ can be deposited using the aforementioned PVD methods, arcing (Are), reactive cathode sputtering (Sputtem) and plasma-activated reactive electron beam evaporation. A sandwich-like structure of the diffusion barrier layer, which is completely gas-impermeable overall, but still survives the expansion of the mechanically loaded container without damage, can be achieved by varying the process parameters, eg a dense, hard layer or a soft, stretchable layer. Metal-containing (elementary) nanoparticles can be incorporated into the layer by co-deposition or by additional use of a molecular beam.

In addition, with plasma-excited (metal organic) chemical vacuum deposition from the gas phase (PE (MO) CVD), a thin diffusion barrier layer, namely a DLC layer with or without passive / active nanoparticles or a thin ceramic layer, for example made of SiO ₂ , Al ₂ O ₃ and / or Si ₃ N ₄ , with or without passive / active nanoparticles, on the

Plastic substrate to be deposited. Regarding DLC layers of submicron thickness with metallic nanoparticles, i.e. Particles in the nm range of a size corresponding to at most 50% of the layer thickness are referred to WO 01/55489 and the following FIG. 9 despite the other function.

- Functional layer system 4: container and film, barrier layer inside and / or outside

A barrier layer comprises a sandwich-like to seven-layer one

Structure, e.g. of the following layers: polymer - metal - polymer - metal oxide - polymer, namely: UV-hardened polyacrylate (1-5 μm) / AI (10-1000 nm) / polyacrylate (0.5 μm) / TiO ₂ (10 -100 nm) / polyacrylate (0.5 μm). The metal and metal oxide layers are evaporated. Instead of the TiO ₂ layer, a DLC, SiON and / or Al ₂ O _{3 can also be} deposited.

This ensures the elasticity of the coating. Thicker layers could e.g. be deposited with plasma spraying (table, item H).

- Functional layer system 5: container, barrier layer preferably inside

A polymer layer is applied as a pretreatment, for example Made of polypropylene, one or a few μm thick, to smooth the surface if necessary, which can also be plasma-activated to increase the adhesion to the following coating. A number of metallic and / or ceramic “brick-like” structural layers are then applied, for example sheet silicates. A polymer-like protective layer which is finally applied ensures the freedom of movement of the brick-like structure. For example, liquid-crystalline polyesters (LCP) can also be stretched biaxially and thereby produce a sheet-like structure.

- Functional layer system 6: container, barrier layer inside and / or outside

A combination of two different deposition processes, the plasma-excited (metal-organic) chemical vacuum deposition from the gas phase (PE (MO) CVD) and the physical vapor deposition from the gas phase (PVD), preferably cathode sputtering, leads to a composite diffusion barrier layer consisting of an inorganic and an organic Material or from various inorganic materials. The inorganic component is a metal (for example aluminum or titanium) or a ceramic (for example Si ₃ N ₄ or Al ₂ O ₃ ), the organic component

Plasma polymer from highly cross-linked hydrocarbon or from a co-polymerized hydrocarbon with oxygen and / or nitrogen.

A measuring transition, i. H. a gradient can be achieved by varying the process parameters or with incorporated particles.

According to the invention, gas-tight tank systems are created for low molecular weight, reactive media, in particular for hydrogen, oxygen, methane and / or methanol. A pressure-resistant plastic container with a weight that is significantly lower for vehicles is lined on the inside and / or outside with a highly effective diffusion barrier layer, which prevents even the smallest quantities of the filling medium from escaping and stores it under legal safety specifications is guaranteed.

The combination of the properties of suitable metal foils, plastic foils and coatings allows such a versatile high barrier foil system to be produced. For the internal coating or lining of plastic containers, a dimensionally independent functional adjustment of the high barrier film system to the respective specifications of the filling medium is required. In other words, the most suitable film combination can be inserted for each filling medium, a layer can be deposited or the most suitable nanoparticles can be integrated into the container wall.

If the plastic container is coated directly, the coating process can be scaled up to the respective dimension. In the case of particularly aggressive filling media, the type and combination of the layers can be adapted accordingly. For example, in the case of a diffusion barrier layer made of aluminum, a further layer can be applied if methanol is used as the filling medium.

Finally, another advantage of the invention lies in the recycling of the plastic container. The diffusion barrier layer can be separated, consists of an equivalent material as the container or has such a low mass fraction that it is of no importance for recycling.

The invention is explained in more detail with reference to exemplary embodiments shown in the drawing, which are also the subject of dependent claims. They show schematically:

1 shows an axial section through a container, FIG. 2 shows a radial section according to II-II in FIG. 1,

- Fig. 3 - 6 variants of details of the container wall in the area A of

Fig. 2, 7, 8 cross sections through prefabricated high barrier film composites,

9 shows a cross section through submicron diffusion barrier layers with and without nanoparticles, and

10 shows a reaction chamber for plasma activation and the production of diffusion barrier layers.

1 and 2, gas-tight, pressure-resistant storage and / or transport container, hereinafter referred to as container 10, has the internationally customary standard dimensions. The container wall 12 equipped with a non-visible diffusion barrier layer consists exclusively of plastic, this wall being produced, for example, using a winding technique known per se. On at least one end face, in the present case on both sides, metallic connecting caps 14 are formed, which narrow to a much smaller diameter and coaxially merge into a closure device 16, which is only shown in block form and which can be held in the region of the longitudinal axis L. Apart from the diffusion barrier layer, which cannot be seen and is shown below, both the container 10 for numerous filling media 20 and its production are known on a broad basis.

In the embodiment according to FIG. 3, the container wall 12 has a diffusion barrier layer 18 on the inside, which is also corrosion protection in the case of an aggressive filling medium 20. The diffusion barrier layer 18 is applied, for example, by inserting a bag made of a metal-plastic composite film or by deposition from the gas phase.

In the variant according to FIG. 3a, passive and reactive nanoparticles 19, which act as a diffusion barrier system, are finely dispersed in the container wall 12 of a hydrogen container. These particles in the nm range are usually designed as clusters, platelets (eg graphite, layered silicates) or tubes based on carbon. The outside atmosphere 24 is also not aggressive, and no corrosion protection is necessary. The container wall 12 according to FIG. 3b, on the other hand, limits a filling 20 with an aggressive component, which is why a diffusion barrier layer 18 is inserted or deposited in addition to FIG. 3a. As in FIG. 3a, the passive nanoparticles are drawn so greatly enlarged that their geometric shape can be seen.

4, the diffusion barrier layer 18 is applied to the outside of the container wall 12. This is inert to the filling medium 20. In the container wall 12 tensile fibers 22 are indicated, in the present case it is steel fibers, in other cases fibers 22 made of carbon, glass or ceramic. The container wall 12 made of plastic is usually reinforced with tensile fibers 22, but for the sake of simplicity these are only shown in FIG. 4.

In the case of an aggressive outside atmosphere 24, the outside diffusion barrier layer 18 also acts as a protection against corrosion. The barrier is shrunk, for example, as an organic diffusion barrier film based on plastic polymers, welded to size or deposited as a layer from the gas phase.

In the presence of an aggressive filling medium 20 and a likewise aggressive outside atmosphere 24, a diffusion barrier layer 18 is applied to the inside and outside of the container wall 12, as shown in FIG. 5.

If neither the filling medium 20 nor the outside atmosphere 24 is aggressive or the container wall 12 is completely inert to both media 20, 24, at least one diffusion barrier layer 18 can be applied as in FIGS. 3 to 5. As shown in FIG. 6, the diffusion barrier layer 18 can, however, also be integrated into the container wall 12 so that it is formed in two parts.

7 shows a prefabricated diffusion barrier layer 18, which consists of a metal foil 26, the actual barrier, and one plastic film 28 laminated on one side. This composite film gives the metal film 26 the mechanical tear resistance required in the application process.

In the composite film according to FIG. 8 with a prefabricated diffusion barrier layer 18, a metal foil 26 or a PVA film with a high barrier effect is protected on both sides with an extruded plastic film 28. Finely dispersed, passive and reactive nanoparticles 19 are embedded in one plastic film 28 and, depending on their constitution, absorb the hydrogen and / or oxygen that diffuses through.

9 shows in section a diffusion barrier layer 18 with a submicron thickness d, which can be arranged on the inside or outside of the container wall 12. In view of the very high magnification factor, the container wall 12 appears flat, although in practice it is cylindrical in shape.

An organic or inorganic layer matrix 30 forming the diffusion barrier layer 18 contains, as shown in FIGS. 3a, 3b and 8, finely dispersed incorporated passive or reactive nanoparticles 19, which have a grain size substantially below the layer thickness d, e.g. B. <(0.1 to 0.2) .d. This diffusion barrier layer 18 is produced from at least one, also substituted hydrocarbon and / or a metal-containing component (PVD, PE-CVD process).

A metallic intermediate layer 34 is arranged between the container wall 12 and the diffusion barrier layer 18 and acts as a further diffusion barrier layer.

10 shows a reaction chamber 36 with a selection of coating options for a container 10, the substrate. In cross section, this container shows a container wall 12 and a container thread 11. A microwave source 38 is arranged in the peripheral region of the essentially cylindrical reaction chamber 36 and is supplied with a radio frequency by a generator 64RF. For the plasma pretreatment and / or plasma coating, the microwave discharge (GHz) 38 or a radio frequency discharge (kHz, MHz) 66 can be coupled in the central area of the reaction chamber 36, with both sources inside and / or outside treatments of the container wall 12 can be carried out.

Furthermore, a cathodic sputtering source 40, 40 'is arranged in the central and in the peripheral region of the reaction chamber 36, which can easily be converted into an arc source 42, 42' if required. Again, both sources 40, 42 and 40 ', 42' can be used with target material 41 for the outside, as for the inside coating of the container 10 used as the substrate. A filter 60 is installed for the outer coating with the arc source 42 '.

An electron beam source or a thermal evaporation source can also be used as further energy sources, not shown in FIG. 10, for the deposition of metal-containing components, boron and silicon, which are oxidized to metal oxides in the reactive gas phase. Preferably all methods are additionally stimulated with plasma.

The reaction chamber 36 can be evacuated via a pump connection 52. A vacuum line leads to a high-performance vacuum pump 50 via a vacuum valve 48. In addition, an inner pump device 54 is arranged.

The gas supply to the reaction chamber 36 takes place via a plurality of gas inlets 44, each of which via a gas regulating valve 46 to the microwave source 38, into the container 10 itself, into the central and peripheral region of the reaction chamber 36, also behind the arc filter 60 and into the atomization source 40 'or into the arc source 42 ', which is opposite the microwave source 38 are arranged, lead. The internal pressure of the reaction chamber 36 is regulated in cooperation with a vacuum measuring device 56.

Strong coils 58 for generating a magnetic field are arranged outside the reaction chamber 36, in the area of the pump connection 52 and opposite. Several generators 64 serve as current sources, which supply the reaction chamber 36 with alternating current in the radio frequency range RF, from low frequency to maximum frequency, and / or with direct current DC. The desired position can be controlled or set manually via two process selector switches 62. An upper process selector switch 42 acting on the target material 41 has a position for a radio frequency generator 64 _RF and a direct current generator 64 _D c. a lower process selector switch 62 connected to the container 10 has a position B for a direct current radio frequency generator 64DC / RF. the generator for bias, F for the ungrounded connection and E for the earth. The container 10, the substrate, can thus be placed on earth E, supply voltage B or open F (floating point).

The coating of a substrate, be it the container wall 12 or a film 28 to be applied thereon, can be carried out in a reaction chamber 36 according to FIG. 10 or in any other reaction chamber, for example by arc, cathode sputtering, plasma-activated evaporation, ion plating, plasma spraying and / or radio frequency discharge. All of these processes can be enhanced with a reactive gas phase and / or with magnetic fields.

The possible uses of the container according to the invention are extremely diverse. For large containers, gas-tight tank systems, especially hydrogen tanks in automotive vehicles, are of particular importance. Small containers are particularly suitable for ventilation of patients or stationary or mobile rooms closed by occupants, for example of aircraft passengers. The following table lists the permeability of coated films and film composites. The last three examples relate to commercially available, uncoated films and are listed shaded.

Tab .: Permeability of coated films and film composites

* Measurement limit

Legend and abbreviations a: Oxygen permeability [ccm / (m ² -d bar)]: ASTM D 3985-95 at 23 ° C and 0% rel. Humidity b: Oxygen permeability [ccm / (m ² -d-bar)]: ASTM D 3985-85 at 23 ° C and 85% rel.

Humidity c: Water vapor permeability [g / m ² -d]: ASTM F1249-90 Standard Test Method at 23 ° C and

90% rel. Moisture (American Society for Testing and Materials, 1997) d: Crack elongation in [%]: formation of microcracks in the layer on a film

DLC Diamond Like Carbon, plasma-polymerized amorphous hydrocarbon layer: a-C: H)

PPpolar plasma polymerized polar layer

PAA polyacrylate

PET = PETP polyethylene terephthalate, polyethylene glycol terephthalate, polyester

OPP oriented polypropylene

PVAL = PVA polyvinyl acetate, polyvinyl alcohol, polyvinyl ether

Hybrid polymer Inorganic-organic hydride polymer (e.g. ORMOCER®)

Claims

claims

1. Gas-tight, pressure-resistant storage and / or transport container (10) for low-molecular, reactive filling media, in particular for hydrogen, oxygen, air, methane and / or methanol, with a high filling pressure, which

The container (10) is essentially rotationally symmetrical and has at least one connection cap (14) with a closure device (16),

characterized in that

the container wall (12) consists essentially of a thermoplastic with at least one diffusion barrier system (18, 19) or a diffusion barrier and corrosion protection system (18, 19).

2. Container (10) according to claim 1, characterized in that it is designed for a filling pressure of at least 150 bar, preferably at least 250 bar, and the container wall (12) essentially made of polyethylene, polypropylene, acetylbutadiene styrene, polyamide or a polyester exists and is optionally armored.

3. Container (10) according to claim 1 or 2, characterized in that the diffusion barrier (18, 19) or diffusion barrier and corrosion protection system (18, 19) is formed over the entire surface as at least one compact layer, the thickness of which is preferably at most about 500 .mu.m, in particular at most about 20 microns, in the case of deposited or vapor-deposited thin layers, preferably 10-600, in particular up to 100 nm.

4. Container (10) according to one of claims 1 to 3, characterized in that the diffusion barrier layers (18) depending on the aggressiveness and permeability of the filling medium (20) and the outside atmosphere (24) inside, outside and / or in the container wall (12 ) arranged themselves are.

5. Container (10) according to any one of claims 1 to 4, characterized in that a prefabricated metal foil (26), preferably as a metal-plastic composite foil (26, 28), or a pure plastic composite foil as a diffusion barrier layer (18) - and / or introduced, a ceramic, boron-containing, silicon-containing and / or metal-containing layer, also a layer protected with a plastic layer, or a pure plastic layer is applied.

6. Container (10) according to claim 5, characterized in that a bag made of a metal-plastic composite film (26, 28) or a pure plastic composite film with a corresponding one or two openings in a cut to the inner mass of the container (IO) the container (10) is inserted and bears against the inside of the container wall (12), and / or a composite film made of plastic is welded to size on the outside of the container wall (12).

7. Container (10) according to one of claims 1 to 4, characterized in that inside and / or outside the container wall (12) a plasma-polymerized, apolar or polar organic diffusion barrier layer (18) is applied on a hydrocarbon basis.

8. Container (10) according to one of claims 1 to 7, characterized in that the diffusion barrier layer (18) is applied to a previously plasma-treated and / or smoothed container wall (12).

9. Container (10) according to one of claims 1 to 8, characterized in that the diffusion barrier system (19) in the container wall (12), in at least one composite film (26, 28) and / or in at least one diffusion barrier layer (18) finely dispersed distributed, passive or reactive nanoparticles (19) for adsorbing or reacting with permeating gas, which nanoparticles (19) preferably comprise titanium, palladium, iron, aluminum, magnesium, Mg ₂ Ni, TiC, TiO ₂ , T Al, TiN, Ti2Ni, LaNi ₅ H ₆ , graphite, layered silicates and / or carbon-containing nanotubes.

10. Container (10) according to claim 9, characterized in that the nanoparticles (19) are embedded in a matrix, in particular reactive Ti or passive TiN nanoparticles in an Si ₃ N matrix or passive TiO ₂ nanoparticles in an SiO ₂ matrix.