Sealing elements suitable for hydrogen barriers

Abstract

The present invention relates to a sealant suitable as a hydrogen barrier, including a substrate. The present invention also relates to a matrix material for a composite material, including a substrate. The sealant or matrix material of the present invention is characterized in that it includes a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a sealant that can be used as a hydrogen barrier, a method for manufacturing the sealant, a matrix material for a fiber composite material that can be used as a hydrogen barrier, and a method for manufacturing the matrix material. [Background technology]

[0002] The energy carrier hydrogen is becoming increasingly important in the transition to renewable energy sources. Hydrogen can be produced in areas where renewable energy is abundant and transported from there to urban areas where energy is primarily consumed. Energy can also be temporarily stored or accumulated in the form of hydrogen. However, transporting and storing hydrogen requires transportable containers and pipelines through which hydrogen can be transported and stored. These containers and pipelines are usually made of steel, but can also be made of fiber composite materials.

[0003] The hydrogen atom is the smallest atom in the periodic table, which places special demands on the materials used to make hydrogen containers and pipelines, as its size means it tends to penetrate materials such as steel and fiber composites.

[0004] The tendency of a material to take up or transmit hydrogen can be determined using permeability measurements in accordance with DIN EN ISO 17081 and EP 3 553 210 A1. Here, a material sample is placed between two electrodes; as hydrogen passes through the material sample, a current flows between the two electrodes. The higher the detected current, the greater the hydrogen diffusion in the material sample, and vice versa. In this case, in the case of steels and fiber composites, a significant degree of hydrogen diffusion through the material occurs.

[0005] Once hydrogen penetrates a material, it causes changes in the crystalline structure of the steel types typically used in the construction of vessels and pipelines, resulting in a loss of mechanical strength. For example, fiber composites with an epoxy resin matrix tend to become brittle. As a result, vessels and pipelines made from steel or fiber composites lose their mechanical strength over time and must be replaced.

[0006] The object of the present invention is therefore essentially to provide a sealant and matrix material for fiber-reinforced plastics which has the highest possible resistance to hydrogen diffusion and penetration in order to extend the service life of vessels and pipelines, and which is inexpensive to produce and easy to process. Summary of the Invention

[0007] This object is achieved by an article and a method having the features set forth in the independent claims. Further particularly advantageous embodiments of the invention are set forth in the respective dependent claims.

[0008] The elements recited in the claims may be combined to the fullest extent technically possible (for example, between different categories such as a method and an apparatus) to form other embodiments of the present invention. Furthermore, this specification, particularly with reference to the drawings, characterizes and specifies the present invention.

[0009] Furthermore, as used herein, the conjunction "and / or" placed between and connecting two features should always be interpreted as follows: in a first embodiment of the inventive subject matter, only the first feature may be present, in a second embodiment, only the second feature may be present, and in a third embodiment, both the first and second feature may be present.

[0010] The sealant according to the present invention is a sealant according to the present invention that can be used as a hydrogen barrier for a substrate, and is characterized in that it contains a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

[0011] The sealant is suitable as a barrier to hydrogen, meaning that hydrogen is essentially impermeable to the sealant, where "essentially impermeable" as used herein means that hydrogen permeates the sealant at less than 5%, preferably less than 2%, and more preferably less than 1% of the amount of hydrogen that would penetrate the surface to be sealed in the absence of the sealant.

[0012] The sealant acts as a barrier to hydrogen because hydrogen molecules are adsorbed onto the sealant and / or cannot penetrate the sealant material at all. Materials such as steel or fiber composites can therefore be sealed with the sealant, preventing hydrogen from reaching the steel or fiber composite through the sealed surface and damaging the material.

[0013] For example, a dispersion base commonly used in exterior paints may be used as the base material, i.e., the sealant can be easily applied to the surface to be protected, as is common with exterior coatings. The sealant provides full protection when dry, but may also provide protection even in a liquid state that is not yet completely dry.

[0014] The thickness of the layer should be in the range of 0.2 mm to 1 mm, preferably 0.5 mm, to ensure consistent mechanical stability and performance of the sealant. In practice, two successive 0.25 mm coatings are sufficient. Since the protective effect is achieved only by sealing the surface of the sealant, the layer thickness can be very small, for example, 0.2 mm or less.

[0015] Aluminum-based additives are known to reduce the hydrogen permeability of materials. However, aluminum in conventional dispersion-based materials leads to the formation of cracks and / or pores when the sealant dries. Therefore, even if hydrogen can no longer permeate the sealant itself, it can still permeate through these cracks and pores, effectively leaving the surface that should be protected from hydrogen unprotected.

[0016] Therefore, the central concept of the present invention is to add zinc powder, nano silicon dioxide, and a plasticizer to the sealant in addition to aluminum powder, so that after the sealant dries, a continuous layer is formed on the surface to be sealed, which has very low, preferably zero, permeability to hydrogen and at the same time has substantially no cracks or through holes through which hydrogen can reach the surface to be protected.

[0017] In this regard, the plasticizer provides a certain elasticity to the matrix of the sealant, suppressing the formation of cracks and pores when the sealant dries, and functions to minimize the formation of cracks and pores. The nano silicon dioxide also significantly contributes to suppressing the formation of cracks and pores when the sealant dries.

[0018] The aluminum powder and the zinc powder form plate-like structures that reinforce the matrix of the sealant, and these structures made of aluminum and zinc ultimately make the sealant impermeable to hydrogen.

[0019] Advantageous embodiments of the invention and variants thereof are defined in the dependent claims and the following description. The individual features defined in the dependent claims can be combined in a technically feasible manner with each other and with the features detailed in the following description to form further advantageous variant embodiments.

[0020] In one embodiment of the sealant, the substrate comprises pure acrylate and / or styrene acrylate and / or styrene butadiene, preferably consisting of only one of these materials or a combination of these materials.

[0021] Pure acrylates are currently the mainstream base for exterior paints because they are less harmful to health than, for example, nitro-based paints or alkyd resin varnishes, and have excellent properties such as UV resistance and coating properties. Furthermore, pure acrylates are widely available, making them inexpensive and of good quality. When referring to pure acrylates in this application, the acrylate preferably refers to a dispersion of methyl acrylate and water having a solids content of 35-45%, more preferably 40%, and further containing 2-4%, more preferably 3%, of an emulsifier, such as Pemulen.

[0022] However, in addition to pure acrylates, styrene acrylates and styrene butadienes are also suitable, as these materials impart excellent mechanical strength to the sealant and can be used, for example, when surfaces that are subject to high mechanical loads must be sealed.

[0023] In another embodiment of the sealant, the plasticizer comprises Plastilt 3060 from BASF and / or APEO-free polypropylene glycol alkyl phenyl ether. Preferably, the plasticizer consists of only one of these materials or a combination of these materials.

[0024] In another embodiment of the sealant, the nano silicon dioxide preferably has a particle size substantially entirely less than 10 nm. Nano silicon dioxide is characterized by a nanoscale particle size. Advantageously, the particle size of the particles is less than 10 nm. Generally, powders have a particle size distribution, so the particles have a particle size substantially less than 10 nm, meaning, for example, that at least 90% of the particles have a particle size less than 10 nm.

[0025] In another embodiment of the sealing material, the aluminum powder has an average particle size of 0.1 to 50 μm, preferably 30 μm. The average particle size represents the most prevalent particle size in the powder. Larger and smaller particles are present in small amounts, for example in a Gaussian distribution.

[0026] In another embodiment of the sealing material, the zinc powder has an average particle size of 0.1 to 50 μm, preferably 50 μm.

[0027] In another embodiment of the sealant, the sealant comprises the following specified proportions of each material: a. 50-90% pure acrylate, and / or b. 1-3% white spirit, and / or c. 0.1-1.0% preservatives, and / or d. 1-5% nano silicon dioxide, and / or e. 3-10% plasticizer, and / or f. 1-10% aluminum powder, and / or g. 1-10% zinc powder, and / or h. 0.5-30% water.

[0028] A sealing material containing the above materials in the respective proportions is highly suitable as a hydrogen barrier.

[0029] The white spirit is a mineral spirit, which has the effect of lowering the hardening temperature of the sealant. As the preservative, for example, Preventol (phenylphenol) may be used.

[0030] It has been found that a sealant composition containing the following ingredients in the proportions shown below is particularly preferred: a. 80% pure acrylate, and / or b. 2% white spirit, and / or c. 0.3% preservatives, and / or d. 2% nano silicon dioxide, and / or e. 5% plasticizer, and / or f. 2% aluminum powder, and / or g. 5% zinc powder, and / or h. 3.7% water.

[0031] Laboratory tests, evaluated in accordance with DIN EN ISO 17081 and EP 3553210 A1, have shown that such sealing materials are completely impermeable to hydrogen.

[0032] The substrate to be sealed with the sealant according to the present invention is characterized in that the sealant contains a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

[0033] In one embodiment of the substrate to be sealed, the sealant is applied to the surface of the substrate in a layer thickness of at least 0.2 mm. Preferably, the sealant is applied in two layers, and the dried sealant on the substrate consists of two layers, each layer having a thickness of at least 0.1 mm.

[0034] In another embodiment of the substrate to be sealed, the substrate comprises iron and / or steel and / or fiber-reinforced plastic. Preferably, the substrate consists of one or more of the aforementioned materials. Preferably, the substrate forms a pipeline or a vessel for transporting or storing hydrogen. The substrate may also form any element that may come into contact with hydrogen in the construction of the pipeline or vessel, such as, for example, valves, bushings, fittings, etc.

[0035] In addition to the sealant, a method according to the invention is claimed for producing a sealant that can be used as a hydrogen barrier using a substrate, characterized in that a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder are added to the substrate in a mixing step by mechanical mixing.

[0036] In the mixing step, the individual components of the sealant are added to the base material in small portions and mixed together by continuous stirring, for example, with a stirrer. It is important to avoid causing foaming as much as possible during mechanical mixing.

[0037] In one embodiment of the method, the mechanical mixing is performed under vacuum conditions during the production of the sealant. It is important that as few air bubbles as possible are introduced into the sealant during mechanical mixing, as these may later cause porosity in the sealant. Therefore, it is beneficial to perform the mechanical mixing under vacuum conditions, thereby preventing air bubbles from being incorporated into the sealant. It may also be useful to subject the sealant to a vacuum after mechanical mixing to remove any entrapped air bubbles.

[0038] In another embodiment of the method for producing the sealant, the mechanically mixed materials (base material, plasticizer, nano-silicon dioxide, aluminum powder, zinc powder, and other additives) are fed to a colloidal processor for processing, so that the components of the sealant are mixed as finely as possible, and the aluminum powder and zinc powder can form a plate-like structure when the sealant hardens, thereby reinforcing the sealant.

[0039] The present invention also encompasses a matrix material for a fiber composite material that can be used as a hydrogen barrier in a substrate, characterized in that the matrix material contains a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder. The plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder make the matrix material of the fiber composite material impermeable to hydrogen. Therefore, a fiber composite material having the matrix material of the present invention is impermeable to hydrogen itself and does not need to be protected from hydrogen penetration by an additional sealant.

[0040] In a preferred embodiment of the matrix material, the substrate comprises a 2K material, which has the advantage that the curing process can be precisely controlled and which often has good resistance to solvents after curing.

[0041] In another preferred embodiment of the matrix material, the base material comprises a pure acrylate. Epoxy resins are widely used as matrix materials and have proven their value. However, epoxy resins become brittle when in contact with hydrogen and are prone to pores and cracks during curing, making it necessary to use a different base material. It has been found that pure acrylates can be used as the base material for matrix materials and can be made impermeable to hydrogen by the additive according to the invention.

[0042] The fiber composite plastic material according to the present invention is characterized in that it comprises a fibrous material and a matrix material, and the matrix material contains a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

[0043] In one embodiment of the fiber composite plastic material, the fibrous material is embedded in the matrix material, and is therefore almost completely surrounded by the matrix material, where "almost completely" in the present application means that the fibrous material does not necessarily have to be surrounded by matrix material, for example at the end of a component produced from the fiber composite plastic material and subsequently cut.

[0044] In another embodiment of the fiber composite plastic material, the fibrous material comprises glass fibers, and / or carbon fibers, and / or Kevlar fibers, and / or natural fibers, and / or metal fibers, preferably consisting of one or more of the aforementioned materials.

[0045] The method for producing a matrix material for a fiber composite material that can be used as a hydrogen barrier using a substrate according to the present invention is characterized in that a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder are added to the substrate in a mechanical mixing process.

[0046] In one embodiment of the method, the mechanical mixing is performed under vacuum conditions during the preparation of the matrix material. It is important that as few air bubbles as possible are introduced into the matrix material during mechanical mixing, as these may subsequently cause pores in the matrix material. Therefore, it is advantageous to perform the mechanical mixing under vacuum conditions, thereby preventing air bubbles from being incorporated into the matrix material. It may also be useful to subject the matrix material to a vacuum after mechanical mixing in order to remove any entrapped air bubbles.

[0047] In another preferred embodiment of the method for producing the matrix material, the materials (base material, plasticizer, nano-silicon dioxide, aluminum powder, zinc powder, and additives) that have been mechanically mixed in advance are fed into a colloidal processor for processing, and the aluminum powder and zinc powder can form plate-like structures during the curing of the sealant, thereby reinforcing the sealant. [Brief explanation of the drawings]

[0048] Exemplary embodiments of the present invention will now be described in more detail with reference to the accompanying drawings.

[0049] [Figure 1]FIG. 1 is a diagram showing a substrate to be sealed, in which a sealing material according to the present invention is disposed inside a steel pipe-shaped substrate.

[0050] [Figure 2] FIG. 2 shows a fiber composite plastic material comprising fibrous material embedded in a matrix material according to the present invention.

[0051] [Figure 3] FIG. 3 shows a substrate to be sealed made from steel, with a sealant according to the invention placed on one side. Detailed Description

[0052] In the drawings, unless otherwise stated, the same reference numerals indicate the same components or components that correspond to each other and have the same function.

[0053] FIG. 1 shows a substrate to be sealed, in which a sealant 2 is placed inside a steel pipe-shaped substrate 1. Here, the sealant 2 is formed as a thin layer compared to the wall of the steel pipe, with a thickness of 0.2 mm, while the wall of the steel pipe is 3 mm thick. The sealant 2 prevents hydrogen from permeating, and the inner surface of the steel pipe does not come into contact with hydrogen. In other words, hydrogen does not pass through the steel pipe and reach the outside.

[0054] Figure 2 shows a fiber composite plastic material comprising a fibrous material 3 embedded in a matrix material 4, where the matrix material 4 completely covers the fibers of the fibrous material 3 and chemically hardens, thereby forming a mechanically stable fiber composite plastic material from the fibrous material 3 and the matrix material.

[0055] 3 shows a substrate 1 to be sealed made of steel, with a sealant 2 according to the present invention disposed on one side. Here, the sealant 2 is formed in a two-layer structure on one side of the steel substrate 1, with each layer having a thickness of about 0.1 mm.

[0056] The sealant has a composition containing the following materials in the following proportions: a. 80% pure acrylate, and / or b. 2% white spirit, and / or c. 0.3% preservatives, and / or d. 2% nano silicon dioxide, and / or e. 5% plasticizer, and / or f. 2% aluminum powder, and / or g. 5% zinc powder, and / or h. 3.7% water.

[0057] Substrate 1 in Figure 3, sealed on one side with sealant 2, was subjected to permeation measurements using an electrochemical measuring device in accordance with DIN EN ISO 17081 and EP 3 553 210 A1. Laboratory tests showed that sealant 1 was completely impermeable to hydrogen. Reference Code List

[0058] 1 Base material 2. Sealant 3. Fibrous materials 4. Matrix material

Claims

1. A sealing material usable as a hydrogen barrier, comprising a substrate, The sealant is characterized by including a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

2. A sealing material according to the preceding claim, The substrate is characterized in that it comprises pure acrylate and / or styrene acrylate and / or styrene butadiene, preferably consisting of pure acrylate and / or styrene acrylate and / or styrene butadiene.

3. 10. The sealing material according to claim 1, The plasticizer comprises Plastilit and / or polypropylene glycol alkylphenyl ether, and preferably consists of Plastilit and / or polypropylene glycol alkylphenyl ether.

4. 10. The sealing material according to claim 1, The nano-silicon dioxide is preferably characterized by a particle size substantially entirely of less than 10 nm.

5. 10. The sealing material according to claim 1, The aluminum powder is characterized in that the average particle size is 0.1 to 50 μm, preferably 30 μm.

6. 10. The sealing material according to claim 1, The zinc powder is characterized in that the average particle size is 0.1 to 50 μm, preferably 50 μm.

7. 10. The sealing material according to claim 1, The sealant is characterized by containing the following materials in the proportions specified below. a. 50-90% pure acrylate, and / or b. 1-3% white spirit, and / or c. 0.1-1.0% preservative, and / or d. 1-5% nano silicon dioxide, and / or e. 3-10% plasticizer, and / or f. 1-10% aluminum powder, and / or g. 1-10% zinc powder, and / or h. 0.5-30% water.

8. A substrate to be sealed using the sealant according to claim 1, The sealant is characterized by including a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

9. The substrate to be sealed according to the preceding claim, The sealant has a layer thickness of at least 0.2 mm on the surface of the substrate, and preferably the sealant consists of two layers, each layer having a layer thickness of at least 0.1 mm.

10. A substrate to be sealed according to one of the two preceding claims, The substrate comprises iron and / or steel and / or fiber-reinforced plastic, and is preferably made of iron and / or steel and / or fiber-reinforced plastic.

11. A method for producing a sealing material that can be used as a hydrogen barrier, comprising: The method is characterized in that the plasticizer, nano silicon dioxide, aluminum powder, and zinc powder are added to the base material in a mixing step by mechanical mixing.

12. 10. The method of claim 1, wherein The mechanical mixing is performed under vacuum during the production of the sealant.

13. 10. The method according to claim 8 or 9, During the production of the sealant, the mechanically mixed materials are processed using a colloidal mixer.

14. A matrix material for a fiber composite plastic material that can be used as a hydrogen barrier, comprising a substrate, The matrix material is characterized by including a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

15. A matrix material according to the preceding claims, The substrate is characterized in that it contains a 2K material.

16. A matrix material according to the preceding claims, The substrate is characterized in that it comprises, and preferably consists of, a pure acrylate.

17. A fiber-plastic composite material comprising a fibrous material and a matrix material according to one of the preceding four claims, The matrix material is characterized by including a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder.

18. A fibre-composite plastic material according to the preceding claim, The fibrous material is embedded in the matrix material.

19. A fiber-composite plastic material according to one of the two preceding claims, The fibrous material comprises glass fibers, and / or carbon fibers, and / or Kevlar fibers, and / or natural fibers, and / or metal fibers, and is preferably made of glass fibers, and / or carbon fibers, and / or Kevlar fibers, and / or natural fibers, and / or metal fibers.

20. A method for producing a matrix material for a fiber composite material that can be used as a hydrogen barrier, which includes a substrate, is characterized in that a plasticizer, nano-silicon dioxide, aluminum powder, and zinc powder are added to the substrate in a mixing step by mechanical mixing.

21. 10. The method of claim 1, wherein The mechanical mixing is performed under vacuum conditions during the preparation of the matrix material.

22. 16. The method according to claim 14 or 15, During the preparation of the matrix material, the mechanically mixed material is treated using a colloidal mixer.

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