DE102018213140A1 - Multi-layer composite and fluid line - Google Patents

Abstract

The present invention relates to a multilayer composite, in particular for a fluid line, with a primary layer made of a first material having a partially crystalline isotactic homo-polypropylene, a secondary layer following the primary layer made of a second material having an adhesion promoter, and a tertiary layer made of a one following the secondary layer Third material comprising polyamide, the first material having, in addition to the homo-polypropylene, an anti-oxidant with a proportion of at least 0.05% to at most 0.4%, based on the total mass of the first material. The invention further relates to a fluid line.

Description

The invention relates to a multilayer composite, in particular for a fluid line, and furthermore to a fluid line made of a multilayer composite.

The publication is, for example, from the prior art EP 1 771 298 B1 known. This relates to a multilayer coolant line which contains an outer layer made of a polyamide molding compound and an inner layer made of a stabilized polyolefin molding compound. The subject of EP 1 771 290 B1 is characterized in particular by the fact that the outer layer consists of a polyamide molding compound and the inner layer consists of a polypropylene molding compound which contains at least 50% by weight of polypropylene and at least 0.02% by weight of a heat stabilizer, the polypropylene being a heterophase copolymer of propene and ethene and the inner layer is at least 0.4 mm thick. Furthermore, the EP 1 771 298 B1 that especially polypopylene as a polyolefinic inner layer quickly becomes brittle under operating conditions.

The fluid line can be designed, for example, as a coolant line. In principle, there is an increased need for such coolant lines in vehicles, where they are used, for example, to circulate a liquid coolant as a heat carrier with a high heat capacity in a closed circuit, which contains at least one heat source and one heat sink. The at least one heat source and the at least one heat sink can differ depending on the vehicle and drive concept or also depending on the operating and environmental condition of the vehicle. In a vehicle with a classic internal combustion engine in normal operation, for example, the coolant flows around the cylinder walls as the heat source, and the main air / water heat exchanger, which emits the waste heat to the environment, must be identified as the heat sink.

The embodiments of cooling systems and the requirements for coolant-carrying line systems for vehicles are currently in the process of being very differentiated. In vehicles that are operated solely by means of classic internal combustion engines, the complexity of the coolant circuits has increased significantly in recent years. On the one hand, this is due to the fact that ever stricter emissions laws and strong requirements for use and comfort have created new heat sources and had to be integrated into the cooling systems. EGR coolers, exhaust gas turbochargers and charge air coolers are worth mentioning here.

On the other hand, with increased power densities of the internal combustion engines, the installation spaces have been encapsulated ever more narrowly and strongly, so that under these conditions the vehicle media and ambient temperatures of the cooling system have increased further and further. For example, it is required that the cooling system and in particular the coolant lines can be operated without any problems at temperatures of at least 130 ° for at least 3000 hours and / or of at least 150 ° C for at least 500 hours. At these temperatures, the vapor pressures of the coolant, for example a water-containing mixture, in particular a mixture of water and a coolant additive, and the delivery pressures of the pumps provided for conveying the coolant through the coolant lines result in pressures in the coolant lines of, for example, at least 2 bar, at least 3 bar or at least 4 bar.

At the same time, the branching of the coolant circuits has increased due to new components and the division into sub-circuits, which enable flow quantities to be regulated as required (for example, by means of map thermostats and additional electrical pumps) and thus the local temperatures in the coolant circuit. This has made the coolant circuits more complex. New interfaces have also been created, which is why increasing emphasis is being placed on low-differential and low-noise flows in the coolant circuits. At the same time, weight-saving and economical solutions for components and component walls had to be found. Finally, the mostly glycol-based coolant additives were further developed, some of which can have enormous effects on material aging.

In the recent past, in addition to vehicles operated purely by means of internal combustion engines, there have been vehicles which are at least partially or completely electrically driven. These vehicles are available as hybrid vehicles or electric vehicles. The hybrid vehicles have different drive units that drive the vehicle separately from one another and / or at least temporarily together. One of the drive units is, for example, in the form of the internal combustion engine already mentioned and another as an electric motor. The electric vehicles, however, only have one or more electric motors to drive them. The electric motor or the electric motors are operated at least temporarily by means of batteries. Batteries for such electrically powered vehicles are therefore increasingly being developed.

These vehicles also require coolant circuits, but sometimes with different design focal points. The main units like The electric motor (s), power electronics and / or battery not only have to be cooled, but also have to be temperature-controlled for maximum efficiency, that is, set to a specific operating temperature. The temperature levels of the coolant and the environment are significantly lower than in vehicles with internal combustion engines. However, the regulation must be much more precise than in vehicles with an internal combustion engine, especially because there is significantly less waste heat. This can result in an even greater branching of the coolant circuit, which leads to even more complex line systems. All in all - especially in the case of purely electrically powered vehicles - all forms of energy have to be used much more economically, which results in requirements for low pressure loss flows, low masses and thermal insulation.

The cooling systems not only extend into the front part of the vehicle (engine compartment), as is the case with established vehicles with a combustion engine, but also, due to the installation position of the energy storage devices, often over the entire vehicle, for example from the engine compartment to an assembly located in the rear of the vehicle. Together with a lower noise level of the drive, this leads to higher requirements for acoustics (flow noise, airborne and structure-borne noise transmission). In addition, strains due to changes in pressure and temperature must be able to be compensated to a greater extent by the line systems; holders and guides of the lines must be able to be fastened accordingly. Special regulations for the cables may then have to be observed, in particular for battery cables of battery-electric vehicles. Under certain circumstances, specifications regarding fire and further fire behavior (e.g. UL94 tests on the flammability of plastics) must be observed.

Furthermore, due to the proximity to the interior, there must be increased requirements for odor emissions from the coolant lines (inherent odor, for example due to volatile aromatic hydrocarbons, for example from plasticizer components) and the penetration of odor from the coolant into the interior. For battery-electric vehicles, there may be increased requirements for ion discharge upon contact with coolant mixtures as well as external electrical insulation or a certain electrostatic discharge capacity.

In the case of hybrid vehicles, additional coolant lines and / or a separation of the coolant circuit into separate high and low temperature circuits may be necessary.

Common requirements for fluid lines are a high short-term vacuum resistance to ensure a quick system initial filling with the coolant, for example directly from the manufacturer. In addition, a certain impact strength, including cold impact, must also be achieved after heat aging in air and in coolant. In addition, in recent years there has been a trend towards ever more diverse vehicle variants (platforms, special equipment, markets) and derivatives with ever shorter change periods (product optimizations), in which a multitude of different line systems have to be handled.

The described change in the requirements for coolant lines in vehicles, especially in electric vehicles, requires consideration of new requirements-oriented concepts for coolant lines, after all, in addition to technical requirements due to the described increased line lengths for each vehicle, very high economic requirements must also be met in production.

It is an object of the invention to propose a multi-layer composite, in particular for a fluid line, which has advantages over known multi-layer composites, is particularly inexpensive to manufacture and is also extremely durable, preferably fluid-resistant and / or temperature-resistant, so that it also meets high continuous load requirements in conjunction with high temperature requirements are.

This is achieved according to the invention with a multilayer composite with the features of claim 1. It is envisaged that the multilayer composite has the following: a primary layer made of a first material having a partially crystalline isotactic homo-polypropylene, a secondary layer following the primary layer made of a second material having an adhesion promoter and a tertiary layer following a secondary layer made of a third having a polyamide Material, wherein the first material in addition to the homo-polypropylene has an anti-oxidant in a proportion of at least 0.05% to a maximum of 0.4%, based on the total mass of the first material.

The multilayer composite, which is particularly preferably used to manufacture or form the fluid line, has in this respect at least three layers, namely the primary layer, the secondary layer and the tertiary layer. The layers mentioned preferably follow one another directly, so that the secondary layer lies directly on the primary layer and the tertiary layer lies directly on the secondary layer or directly on the latter borders. In other words, the secondary layer is arranged between the primary layer and the tertiary layer and bears on the one hand on the primary layer and on the other hand on the tertiary layer. The primary layer and / or the secondary layer and / or the tertiary layer are each individually designed to be of the same material, so that the respective layer consists entirely and consistently of the material designated in each case.

The primary layer consists at least partially or completely of the first material, the secondary layer at least partially or completely of the second material and the tertiary layer at least partially or completely of the third material. The materials are different from each other. In other words, the first material is different from the second material and the third material, the second material from the first material and the third material and the third material from the first material and the second material. However, it can be provided that at least two of the materials or all materials are based on a common base material which is provided with different additives or additives for the different materials.

The first material is in the form of homopolypropylene or at least has this. This means that the first material may contain only homopolypropylene or may contain other substances, in particular additives, in addition to it. The homo-polypropylene can be electrostatically conductive and / or flame retardant additive. However, this can have an impact on the impact resistance, so that the homo-polypropylene with additive has a higher conductivity and / or is less flammable than the homo-polypropylene without additive, but has a lower impact resistance. The homo-polypropylene is a plastic with a density that is, for example, in the range from 0.89 g / cm ³ to 0.92 g / cm ³ . It is well suited for pipe extrusion and / or fluid line extrusion and has a high fatigue strength. Furthermore, its surface energy is very low, which makes the chemical resistance and / or the resistance to microorganisms very good. The homo-polypropylene can hardly be glued, but it is easy to weld. In addition, the homo-polypropylene represents a good water barrier to the outside and / or has a high level of rigidity, strength and / or heat resistance, especially in connection with a very good abrasion behavior. Furthermore, the acoustic damping properties of homo-polypropylene can be very good.

It can be provided that the anti-oxidant of the first material is selected from a group consisting of pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), such as, for example, Irganox® 1010, N , N'-hexane-1,6-diylbis (3- (3,5-di-tert-butyl-4-hydroxyphenylpropionamide)), such as, for example, Irganox® 1098, and Okabest ™ PAT 218. It is particularly preferably provided that the product INNOPOL CS 1-8000 MD from Immo-Comp Kft. is used as the semi-crystalline isotactic homo-polypropylene.

With regard to specific products, in particular branded products, such as, for example, Irganox® 1098 or Okabest ™ PAT 218, in the context of this description, a product and / or material is preferably understood which is based on the priority of the manufacturer and / or dealer relevant to the present invention of the product could be obtained.

It is preferably provided that the multilayer composite consists exclusively of the three layers mentioned, so that the primary layer and the tertiary layer are each present as an outer layer or, in the case of the fluid line, the primary layer is present as an inner layer and the tertiary layer as an outer layer. In the latter case in particular, the primary layer thus serves to guide a fluid in the fluid line, the excellent resistance of the partially crystalline isotactic homopolypropylene to a fluid which is carried in the fluid line being used.

The multilayer composite of the primary layer, the secondary layer and the tertiary layer can be in the form of a three-layer barrier system or can be referred to as such. The three-layer barrier system is resistant to permeation, oligomer washout and / or water. Regardless of its design, the multilayer composite is preferably used to manufacture the fluid line. However, it can also be used to form any other body, in particular hollow body, such as a fluid container or the like.

The second material is in the form of the adhesion promoter or at least has this. The second material can therefore consist exclusively or only partially of the adhesion promoter. It is preferably provided that the adhesion promoter is an easy-flowing adhesion promoter. This is successfully used for example in the packaging industry for polypropylene films. The adhesion promoter is preferably based on the partially crystalline isotactic homo-polypropylene used for the primary layer of the multilayer composite according to the invention and, in addition to this, contains an additive, for example maleic anhydride, as the active element. In other Words, the first material of the primary layer and the second material of the secondary layer can only differ with regard to the additive. Alternatively, the adhesion promoter can be a homo-polypropylene which is different from the first material used for the primary layer and which is mixed with an additive, in particular the maleic anhydride. The product ADMER ™ QB520E from Mitsui Chemicals is particularly preferably used as an adhesion promoter.

Furthermore, it is preferably provided that the first material has, in addition to the homopolypropylene, a metal deactivator in a proportion of at least 0.05% to at most 0.4%, based on the total mass of the first material. This has the advantage, for example, that the metal deactivator, in particular, can improve the resistance to the degradation effect of copper-containing metal inserts. The partially crystalline isotactic homo-polypropylene used for the primary layer is preferably characterized in that it has a melting temperature (T _m value) or a melting range from 155 ° C. to 180 ° C., in particular 160 ° C. to 165 ° C., in particular 162, 5 ° C. It is preferably provided that the metal deactivator is a chelate ligand. Furthermore, it is particularly preferably provided that the metal deactivator is bis (3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl) hydrazine.

It is preferably provided that the first material has, in addition to the homo-polypropylene, a nucleating agent with a proportion of at least 0.05% and / or up to a maximum of 0.4%, based on the total mass of the first material. It is further preferably provided that the first material has, in addition to the homo-polypropylene, a hydrolysis stabilizer with a proportion of at least 0.05% and / or up to a maximum of 0.4%, based on the total mass of the first material. It is preferably provided here that the hydrolysis stabilizer is a sterically hindered carbodiimide, a metal carboxylate preferably being additionally used as the acid acceptor. Overall, it can therefore be provided that the first material has, in addition to the homo-polypropylene, the anti-oxidant and further additionally the metal deactivator and / or the nucleating agent and / or the hydrolysis stabilizer.

It can be provided that the homo-polypropylene and / or the first material has a proportion of a thermoplastic elastomer (TPE), such as, for example, ethylene-propylene-diene rubber (EPDM). The material obtained from this mixture is also referred to as TPE-O. It is particularly preferably provided that the proportion of the thermoplastic elastomer is added as a polymer to the homo-polypropylene. In other words, this means that the mixture of homo-polypropylene and the thermoplastic elastomer is a blend. This ensures that the impact strength of the material obtained is increased.

Furthermore, it is preferably provided that the multilayer composite has a total thickness of 0.5 mm to 5 mm, preferably 1 mm to 4 mm, particularly preferably 1.5 mm to 3 mm, and / or that a layer thickness of the primary layer becomes a layer thickness of Secondary layer a ratio of 10 to 14 to 2 to 4 and / or the layer thickness of the secondary layer to a layer thickness of the tertiary layer a ratio of 2 to 4 to 14 to 16 and / or the layer thickness of the primary layer to the layer thickness of the tertiary layer a ratio of 10 to 14 to 14 to 16. The total thickness of the multilayer composite is the sum of the layer thicknesses of the primary layer, the secondary layer and the tertiary layer. The total thickness for the fluid line can also be referred to as the wall thickness. The ranges given for the total thickness result in a particularly good ratio between weight and stability of the multilayer composite. The relationships between the layer thicknesses of the individual layers in turn enable a multilayer composite with particularly good properties with regard to permeation and the connection of the layers to one another. The ratios given result, for example, in a ratio of the layer thicknesses of the primary layer, the secondary layer and the tertiary layer to one another from 10 to 14 (primary layer) to 2 to 4 (secondary layer) to 14 to 16 (tertiary layer).

It is preferably provided that the primary layer has a layer thickness of 0.5 to 0.7 mm, the secondary layer has a layer thickness of 0.1 to 0.2 mm and the tertiary layer has a layer thickness of 0.7 to 0.8 mm.

Furthermore, it is preferably provided that the primary layer has a first primary part layer and a second primary part layer, the first primary part layer having a first layer thickness and consisting of the first material, in particular homopolypropylene, and the second primary part layer having a second layer thickness and one Polypropylene random co-polymer, which is preferably selected from a group consisting of Hostalen PP HP1886, Hostalen PP H5416, Hostalen PP XN112-I and Hostalen PP XN125-P. The second layer thickness preferably corresponds exactly or at least corresponds to the first layer thickness. In this respect, the second layer thickness can also be greater than the first layer thickness. The first layer thickness and / or the second layer thickness are in each case preferably 0.2 mm to 0.3 mm. The first primary sublayer consists at least partially, in particular completely, from the first material. The second primary sublayer consists at least partially, in particular completely, of the polypropylene random copolymer. The first primary sublayer and the second primary sublayer preferably adjoin one another directly. The second primary sub-layer preferably adjoins the secondary layer directly, the first primary sub-layer being arranged on the side of the second primary sub-layer facing away from the secondary layer.

In a further development of the invention it is provided that the polyamide of the tertiary layer is selected from a group consisting of polyamide-612 (PA612), polyamide-666 (PA666), polyamide-6 (PA6), polyamide-12 (PA12), polyamide- 66/610 (PA66 / 610), polyamide-66/612 (PA66 / 612) and polyamide-46/6 (PA46 / 6), the polyamides mentioned preferably each having an additive. PA612 has good mechanical properties, in particular low water absorption, high temperature stability, good mechanical wear resistance and good stress corrosion cracking resistance against chemical thawing agents, especially zinc chloride (ZnCl). The tertiary layer made of PA612 thus ensures the mechanical strength in the structure of the fluid line.

The resistance of PA612 to media used in the motor vehicle sector, in particular media present in an engine compartment of a vehicle, is very good. Numerous materials based on PA612 are inexpensively available on the market. The PA612 has very good adhesion to the adhesion promoter. If necessary, the material can be thermally joined. If necessary, the material can be thermally stabilized with suitable additives, improved cold weather, flame-retardant or optimized for abrasion. For example, holders can be attached to an outer layer of the multilayer composite consisting of PA612, for example by thermal joining. Since the outer layer of the multi-layer composite, in particular in the case of the configuration as a fluid line, preferably also serves or should be usable for marking and labeling, the material preferably also has the property of a color change in conventional laser labeling processes. If printing is to be used for marking, a suitable pigment-rich ink is used.

Furthermore, it is preferably provided that the secondary layer has a first secondary part layer, a second secondary part layer and a third secondary part layer, the first secondary part layer consisting of the second material or a first variation of the second material, the second secondary part layer being an ethylene-vinyl alcohol copolymer (EVOH ) and the third secondary layer consists of the second material or a second variation of the second material. The first secondary part layer and the third secondary part layer preferably accommodate the second secondary part layer between them. In this case, the second secondary part layer particularly preferably borders directly on the one hand on the first secondary part layer and on the other hand directly on the third secondary part layer. The first secondary sublayer in turn preferably adjoins the primary layer, in particular the second primary sublayer. The third secondary part layer borders, for example, on the tertiary layer, in particular on a first tertiary part layer of the tertiary layer.

The first secondary part layer and the third secondary part layer each consist at least partially or completely of the second material or the respective variation thereof. The first variation and the second variation can designate the same material or can be different from one another. In this respect, the first secondary part layer and the third secondary part layer can consist of the same material, namely the second material, or of different materials, which are each based on the second material. For example, one of the layers consists of the second material and the other of the layers consists of the second material provided with an additive. In contrast, the second secondary part layer consists at least partially or completely of the ethylene-vinyl alcohol copolymer.

Furthermore, it is preferably provided that the tertiary layer has a first tertiary part layer and a second tertiary part layer, the first tertiary part layer made from a first variation of the third material, in particular from polyamide-6 (PA6), and the second tertiary part layer from a second variation of the third material, in particular made of polyamide-612 (PA612). The first tertiary layer and the second tertiary layer preferably adjoin one another directly. The first tertiary part layer further preferably adjoins the secondary layer, in particular the third secondary part layer.

It is preferably provided that the first variation and / or the second variation of the third material (in each case) is a polyamide, which is selected from a group consisting of polyamide-666 (PA666), polyamide-6 (PA6), polyamide-12 ( PA12) and copolyamide. In this case, the first variation and the second variation of the third material are preferably different from one another. The polyamide, in particular polyamide-6, preferably contains a plasticizer and / or is - more preferably - designed as a copolyamide. The first tertiary layer and / or the second tertiary layer preferably have ( in each case) a layer thickness or wall thickness of 0.2 to 0.4 mm, preferably 0.3 mm.

According to a development of the invention, it is provided that at least one of the three layers of the multilayer composite, that is to say the primary layer, the secondary layer and the tertiary layer, has reinforcing fibers and / or the multilayer composite between the primary layer and the secondary layer and / or between the secondary layer and the tertiary layer has a fabric layer of reinforcing fibers. The reinforcing fibers serve to reinforce the multilayer composite or the respective layer, in particular for mechanical reinforcement. The reinforcing fibers can in principle be arranged in any way. They are preferably embedded in the material of the respective layer, so that the material is in the form of a fiber composite material. The material serves as a matrix in which the reinforcing fibers are embedded. In the context of this description, the term “fabric”, in particular “fabric layer”, is preferably understood to mean a product which is obtained by weaving continuous fibers, such as, for example, a roving.

The reinforcing fibers are preferably in the form of long fibers which — more preferably — are oriented in the main loading direction, usually in the longitudinal direction, of the multilayer composite. In other words, the reinforcing fibers preferably run at least generally or continuously parallel to the main loading direction or the longitudinal direction. The long fibers can be part of a fabric or scrim. This fabric or scrim is preferably embedded in the material or is present between two of the layers. However, the reinforcing fibers can also be in the form of short fibers, which are preferably arranged in a tangled fashion. For example, carbon fibers, glass fibers, ceramic fibers, aramid fibers, metal fibers, in particular steel fibers, natural fibers or the like, are used as reinforcing fibers. In the context of this description, the term “long fibers” preferably means reinforcing fibers, each of which has a length of at least 1 mm and / or at most 50 mm.

The invention further relates to a fluid line made of a multi-layer composite, in particular a multi-layer composite according to the statements made in the context of this description, the multi-layer composite comprising a primary layer made of a partially crystalline isotactic homo-polypropylene, a secondary layer following the primary layer made of a bonding agent second material and a tertiary layer following the secondary layer made of a third material having a polyamide, the first material in addition to the homo-polypropylene an anti-oxidant with a proportion of at least 0.05% to a maximum of 0.4%, based on the total mass of the first material.

The advantages of such a configuration of the multilayer composite or of the fluid line have already been pointed out. Both the fluid line and the multilayer composite can be further developed in accordance with the explanations in the context of this description, so that reference is made to this extent.

A further embodiment of the invention provides that the primary layer is an inner layer of the fluid line delimiting a fluid flow space. The partially crystalline isotactic homo-polypropylene first material is particularly resistant to the coolants commonly used in automobile construction, in particular coolants for internal combustion engines. For this reason, the primary layer should directly limit the fluid flow space. For this purpose, it is present as the inner layer of the fluid line.

In a preferred embodiment of the invention, it is provided that the fluid line is present and / or is designed as a corrugated fluid tube. A corrugated fluid pipe is a pipe made of a material with a certain strength, which due to a certain design, namely a corrugation, has a higher flexibility than a design with an undulated shape. The corrugation is formed by a wavy changing diameter in the direction of a longitudinal central axis of the fluid line. This has the advantage that the fluid lines are particularly flexible.

Furthermore, it is preferably provided that the primary layer has a layer thickness of 0.5 to 0.7 mm and / or the secondary layer has a layer thickness of 0.1 to 0.2 mm and / or the tertiary layer has a layer thickness of 0.7 to 0.8 mm.

In connection with the present invention, the term “primary layer” in relation to a fluid line according to the invention can also be understood to mean the “inner layer” which delimits the fluid flow space. Furthermore, it is preferably provided that the inner layer consists of several partial layers, in particular a first inner partial layer - corresponding to the first primary partial layer - and a second inner partial layer - corresponding to the second primary partial layer. In connection with the present invention, the term “secondary layer” in relation to a fluid line according to the invention can also be understood as a “middle layer”. Furthermore, it is preferably provided that the middle layer consists of several Sublayers, in particular a first middle sublayer - corresponding to the first secondary sublayer -, a second middle sublayer - corresponding to the second secondary sublayer - and a third middle sublayer - corresponding to the third secondary sublayer. In connection with the present invention, the term “tertiary layer” in relation to a fluid line according to the invention can also be understood as an “outer layer”. Furthermore, it is preferably provided that the outer layer consists of several partial layers, in particular a first outer partial layer - corresponding to the first tertiary layer - and a second outer partial layer - corresponding to the second tertiary layer.

It can be provided that the fluid line has a fluid line outer layer which is designed as a flame protection layer, abrasion protection layer and / or as a thermal insulation layer. The fluid line outer layer is preferably applied to the outside of the tertiary layer or outer layer or adjoins it, or is at least arranged adjacent to the tertiary layer or outer layer. In the latter case, for example, the fluid line outer layer, viewed in cross section, is arranged in the radial direction at least in regions or at a constant distance from the tertiary layer or outer layer. The fluid line outer layer can be formed subsequently and / or can be applied by an appropriately set up co-extrusion or multilayer process. The fluid line outer layer consists for example of a foamed material. The material of the fluid line outer layer can be a flame retardant material, an abrasion protection material and / or an insulation material.

In a further development of the invention it is provided that the fluid line has a fluid line area in which a cross-sectional adjustment element for adjusting a flow cross-section of the fluid line, in particular a check valve, a control valve or a thermostat, is arranged. This enables a particularly flexible use of the fluid line. Due to the integration of the cross-section adjustment element, there is also a particularly compact design due to the high degree of integration and therefore a small space requirement. The cross-section adjustment element enables the flow cross-section of the fluid line to be adjusted, in particular the flow cross-section of the fluid line that is smallest over the extent of the fluid line. The cross-sectional adjustment element can work automatically, in particular mechanically or thermally. However, it can also be electrically adjustable, for example it is electrically connected to a control unit for this purpose. The cross-sectional adjustment element is preferably in the form of a check valve, control valve or thermostat. Due to the formation of the fluid line area on the fluid line and the arrangement of the cross-section adjustment element in it, the function of a cross-section adjustment element is integrated into the fluid line in a simple and space-saving manner. Through this integration into the fluid line, further connection points / interfaces can be avoided, which would be necessary if a first fluid line section is connected to a cross-section adjustment element and then a second fluid line section is connected to the cross-section adjustment element. Furthermore, there is no need for a further housing along the fluid line, in particular for the cross-section adjustment element, so that no additional installation space is required.

Furthermore, it is preferably provided that the fluid line outer layer is an optimized thermoplastic elastomer (TPE) or a functionally optimized thermoplastic polyurethane (TPU) or a blend of the homo-polypropylene and a thermoplastic elastomer (TPE), such as ethylene-propylene-diene rubber ( EPDM), or consists of them.

Furthermore, it is preferably provided that the fluid line has dimensions which are selected from a group consisting of 8x1 mm, 10x1 mm, 12x1.25 mm, 15x1.5 mm, 16x1.5 mm, 18x1.5 mm, 19.5x1.75 mm, 20x1.75 mm, 22x1.75 mm and 25x2 mm. The dimension at the front denotes the outer diameter or the inner diameter and the dimension at the rear denotes the total thickness or total wall thickness of the layers.

• 1 eine schematische Schnittdarstellung durch eine Fluidleitung aus einem Mehrschichtverbund,
• 2 eine schematische Querschnittsdarstellung der Fluidleitung in einer ersten Variante,
• 3 eine schematische Querschnittsdarstellung der Fluidleitung in einer zweiten Variante,
• 4 eine schematische Längsschnittdarstellung der bereichsweise als Wellrohr ausgestalteten Fluidleitung 11,
• 5 eine schematische Längsschnittdarstellung der Fluidleitung mit einem Rückschlagventil,
• 6 eine schematische Längsschnittdarstellung der Fluidleitung mit einem Thermostat.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without the invention being restricted. It shows

• 1 2 shows a schematic sectional illustration through a fluid line from a multilayer composite,
• 2 1 shows a schematic cross-sectional representation of the fluid line in a first variant,
• 3 1 shows a schematic cross-sectional representation of the fluid line in a second variant,
• 4 is a schematic longitudinal sectional view of the fluid line configured in some areas as a corrugated pipe 11 .
• 5 2 shows a schematic longitudinal sectional view of the fluid line with a check valve,
• 6 is a schematic longitudinal sectional view of the fluid line with a thermostat.

The 1 shows a schematic representation of a fluid line 11 that consist of a multilayer composite 12 consists. The multi-layer composite 12 encompasses to form a fluid flow space 13 the fluid line 11 a longitudinal central axis 14 the fluid line 11 completely in the circumferential direction. The cross-section consists of the multi-layer composite 12 from a primary layer 1 , a secondary layer 2 and a tertiary layer 3 that follow each other in the radial direction outwards. Each of the layers 1 . 2 and 3 is continuous in the circumferential direction and preferably has a constant wall thickness in the circumferential direction.

In the exemplary embodiment shown here, there is the primary layer 1 from a first material which has a partially crystalline isotactic homo-polypropylene or is present as this. On the primary layer 1 follows the secondary layer 2 from a second material which has or is present as an adhesion promoter. On the secondary layer 2 follows the tertiary layer 3 from a third material which has polyamide or is present as such. Here, the first material or the homo-polypropylene has an anti-oxidant with a proportion of at least 0.05% to at most 0.4%, based on the total mass of the first material or - alternatively - the homo-polypropylene and anti-oxidant, on.

It is also preferably provided that the primary layer 1 into a first primary sublayer 1a and a second primary sublayer 1b is divided, the first primary sublayer 1a has a wall thickness of preferably 0.2 mm to 0.3 mm and consists of homo-polypropylene, and the second primary part layer 1b has a wall thickness of preferably 0.2 mm to 0.3 mm and consists of a polypropylene random copolymer which is preferably selected from a group consisting of Hostalen PP HP1886, Hostalen PP H5416, Hostalen PP XN112-I and Hostalen PP XN125-P.

It is also preferably provided that the secondary layer 2 from a first secondary part layer 2a and from a second secondary part layer 2 B and from a third secondary part layer 2c exists, the first secondary part layer 2a an adhesion promoter, the second secondary part layer 2 B an ethylene-vinyl alcohol copolymer (EVOH) and the third secondary layer 2c has an adhesion promoter.

The tertiary layer 3 consists of a first layer of tertiary parts 3a and a second tertiary layer 3b together. The two tertiary layers 3a and 3b are formed continuously in the circumferential direction, that is, they encompass the longitudinal central axis 14 completely in the circumferential direction. The tertiary layers also have 3a and 3b a constant wall thickness in the circumferential direction.

Furthermore, it is preferably provided that the multilayer composite has a total thickness of 0.5 mm to 5 mm, preferably 1 mm to 4 mm, particularly preferably 1.5 mm to 3 mm, and / or that between the layer thicknesses of the primary layer to the secondary layer and to the tertiary layer there is a ratio of 10 to 14: 2 to 4:14 to 16, preferably 10 to 14: 3: 15, particularly preferably 12: 3: 15, and / or a ratio between the layer thicknesses of the primary layer to the secondary layer from 10 to 14: 2 to 4, preferably from 10 to 14: 3, particularly preferably from 12: 3, and / or between the layer thicknesses of the secondary layer to the tertiary layer a ratio of 2 to 4:14 to 16, particularly preferably of 3:15. Furthermore, it is preferably provided that the primary layer has a wall thickness of 0.5 to 0.7 mm, the secondary layer 2 a wall thickness of 0.1 to 0.2 mm, the tertiary layer has a wall thickness of 0.7 to 0.8 mm.

Furthermore, it is preferably provided that the tertiary layer 3 in a first tertiary layer 3a and a second tertiary layer 3b is divided - as mentioned before - where - for example - the first tertiary layer 3a made of polyamide-6 (PA6) and / or the second tertiary layer 3b consists of polyamide-612 (PA612), and preferably the polyamide-6 contains a plasticizer or is designed as copolyamide, and wherein the second tertiary layer 3b preferably has a wall thickness of 0.2 to 0.4 mm, preferably 0.3 mm.

Furthermore, it is preferably provided that the second tertiary layer 3b has a polyamide which is selected from a group consisting of polyamide 666 (PA666), polyamide-6 (PA6), polyamide- 12 (PA12) and copolyamide.

Furthermore, it is preferably provided that at least one of the three layers 1 . 2 and 3 , especially the primary layer 1 , the secondary layer 2 and / or the tertiary layer 3 of the multi-layer network, 12 a reinforcing fiber 15 has or the multilayer composite 12 between the primary layer 1 and the secondary layer 2 and / or the secondary layer 2 and the tertiary layer 3 a layer of fabric 16 made of reinforcing fibers.

It is preferably provided that the fluid line is designed as a corrugated fluid tube. Furthermore, it is preferably provided that the fluid line has a fluid line area in which a cross-sectional adjustment element, in particular a check valve, a control valve or a thermostat, is arranged. The fluid line area is formed, for example, by extrusion, in particular during the extrusion of the fluid line itself. The exact function and structure of the cross-sectional adjustment element will be discussed below.

The fluid line described 11 has just like the multilayer composite 12 , from which the fluid line 11 there is the advantage of a high level of durability combined with very good availability of the materials. The structure of the multilayer composite also enables 11 an inexpensive manufacture. In addition, the fluid line 11 very easy to process, for example through low-permeation and safe connection technologies such as welding, especially laser welding. The welding can preferably be carried out by penetrating a laser beam through the fluid line in a targeted and locally limited manner, the intensity and time of which are matched to the materials and geometries 11 device to be welded, which is made entirely or locally from laser-transparent material. The device is in the form of a fluid coupling, for example. The material of the outer layer of the fluid line, for example the tertiary layer 3 in this case is preferably laser-absorbing to the extent necessary. The material of the respective layer is preferably selected appropriately or made sufficiently laser-absorbent by means of an additive.

Because the outer layer of the fluid line 11 can preferably also be used for labeling and / or labeling, in this case the material should also have the property of a color change in conventional laser labeling processes. If printing is to be used for identification, suitable pigment-rich inks should be preferred.

The materials and / or the wall thicknesses of the individual layers are chosen in particular such that the fluid line 11 can be thermoformed even in narrow bending radii without the use of auxiliary bending tools, for example springs, arranged in the interior of the line. In addition to efficient production, this has further advantages, so that connectors can be added to the fluid line in a rotationally symmetrical state before bending, which minimizes the number of devices. Furthermore, in the case of bending variants based on the same output line lengths, the storage of the preliminary products can be simplified.

From a technical point of view, it is particularly important that, due to the elimination of internal spring springs, there are no local deformations and loads on the inner layer of the fluid line 11 occur. The risk of damage to the layer is reduced. Damage caused by local pressure points on the spiral springs, which would locally reduce the wall thickness of the inner layer, is difficult or even impossible to detect from the outside without destruction.

Furthermore, it is preferably provided that the fluid line 11 a fluid line outer layer 17 has, which is designed as a flame protection layer, abrasion protection layer and / or as a thermal insulation layer. Furthermore, it is preferably provided that the flame retardant layer, the abrasion protection layer and / or the thermal insulation layer is subsequently formed and / or is applied by means of a suitably set up co-extrusion or multilayer process, preferably using a foamed material.

It is also preferably provided that the fluid line outer layer 17 an optimized thermoplastic elastomer (TPE) or a functionally optimized thermoplastic polyurethane (TPU) or a blend of the homo-polypropylene and a thermoplastic elastomer (TPE), such as ethylene-propylene-diene rubber (EPDM), or consists thereof.

The 2 shows a schematic representation of the fluid line 11 in an air gap 18 having embodiment. The air gap 18 is used for thermal insulation of the fluid line 11 , The air gap 18 lies, for example, between the tertiary layer 3 and the fluid line outer layer 17 in front. The air gap 18 encompasses the tertiary layer 3 seen in cross section in the circumferential direction at least partially or even completely. In the embodiment shown here, the air gap is 18 of at least one, preferably several webs 19 , interrupted. In the case of multiple bridges 19 they are spaced apart from one another in the circumferential direction. For example, two of the webs are located 19 diametrically opposite. Four, six or eight webs are preferred 19 available. The jetty 19 or the bridges 19 serve to space the outer layer of the fluid line 17 of other areas of the fluid line 11 , especially the tertiary layer 3 , The at least one footbridge 19 is preferably designed such that the air gap 18 is also present in the event of a bending load, that is to say also in this case the outer layer of the fluid line 17 from the tertiary layer 3 is arranged spaced.

The 3 schematically shows an embodiment of the fluid line 11 , where several air gaps are seen in cross section 18a and 18b available. Basically, the above comments on the air gap 18 and the at least one footbridge 19 directed. The air gap 18a and 18b are from a divider 20 separated from each other. The air gap 18a and 18b are on both sides of the web 19 or one of the bridges 19 limited. In other words, the air gaps extend 18a and 18b each from the footbridge 19 or one of the bridges 19 up to the jetty 19 or another of the bridges 19 , For example, the air gap lying further out in the radial direction is 18b in the fluid line outer layer 17 self-formed, whereas the air gap lying further in the radial direction 18s as explained between the tertiary layer 3 and the fluid line outer layer 17 is arranged.

The 4 schematically shows an embodiment of the fluid line 11 , which is designed in some areas as a corrugated pipe, that is, a corrugated pipe section 21 having. In addition or as an alternative to the corrugated pipe section, the fluid line has 11 over a notch 22 that are in a fluid line area 22a is arranged. The fluid line area 22a serves, for example, the arrangement of a cross-sectional adjustment element, not shown here, which - purely by way of example - serves as a check valve 23 can be trained.

The 5 shows a schematic longitudinal sectional view of the fluid line 11 , This shows the fluid line area 22a and the notch 22 on. Using the notch 22 is the check valve already mentioned 23 in the fluid line area 22a attached, preferably positively attached. The check valve 23 has a spring element 24 by means of which a valve element 25 is spring loaded. The spring element 24 engages on the one hand on the valve element 25 and on the other hand on a valve insert 26 which in turn is in the fluid line area 22a is attached. Is preferably between the valve insert 26 and an inner circumference of the fluid line 11 , especially the primary layer 1 the fluid line 11 , a seal 27 , in particular in the form of a sealing ring or O-ring. The seal 27 is due to both the valve insert 26 as well as sealing on the inner circumference.

A valve seat of the check valve 23 is from the inner circumference of the fluid line 11 self-trained. For example, the valve seat is formed by a step through which a reduction in diameter, in particular an reduction in inner diameter, of the fluid line 11 is formed. The valve element 25 is pushed by the spring force in the direction of the valve seat, in particular to the valve seat. The valve element 25 is designed for example as a ball. Other forms of the valve element 25 can however be realized. Depending on the position of the valve element 25 with respect to the valve seat is a flow connection through the fluid line 11 released or interrupted. In particular, the flow connection is released if the valve element 25 is spaced from the valve seat and interrupted if the valve element 25 sealingly rests on the valve seat. The check valve 23 is designed such that there is a flow through the fluid line 11 in a flow direction with a first flow cross-section, but in an opposite flow direction at least partially with a smaller second flow cross-section or even completely prevented.

The 6 shows a schematic longitudinal sectional view of the fluid line 11 , this instead of the check valve 23 has a cross-sectional adjustment element, which acts as a thermostat 30 is executed. The thermostat 30 is analogous to the check valve 23 in the fluid line area 22a arranged and fastened. Reference is made to the above statements in this regard. The thermostat 30 is preferably designed such that it has a flow connection through the fluid line 11 or the fluid line area 22a if the temperature falls below a temperature limit in the fluid line 11 existing fluid interrupts and releases when exceeded or vice versa.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for better information for the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1771298 B1 [0002]
• EP 1771290 B1 [0002]

Claims (12)

Multilayer composite (12), in particular for a fluid line (11), with a primary layer (1) made of a first material having a partially crystalline isotactic homo-polypropylene, a secondary layer (2) following the primary layer (1) made of a second material having an adhesion promoter and a tertiary layer (3) which follows the secondary layer (2) and is made of a third material comprising a polyamide, the first material, in addition to the homo-polypropylene, an anti-oxidant with a proportion of at least 0.05% to a maximum of 0.4% , based on the total mass of the first material. Multi-layer composite after Claim 1 , characterized in that the anti-oxidant is selected from a group consisting of pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), such as, for example, Irganox® 1010, N, N'- hexane-1,6-diylbis (3- (3,5-di-tert-butyl-4-hydroxyphenylpropionamide)) such as Irganox® 1098 and Okabest ™ PAT 218. Multilayer composite according to one of the preceding claims, characterized in that the multilayer composite (12) has a total thickness of 0.5 mm to 5 mm, preferably 1 mm to 4 mm, particularly preferably 1.5 mm to 3 mm, and / or that a layer thickness of the primary layer (1) to a layer thickness of the secondary layer (2) a ratio of 10 to 14 to 2 to 4 and / or the layer thickness of the secondary layer (2) to a layer thickness of the tertiary layer (3) a ratio of 2 to 4 to 14 to 16 and / or the layer thickness of the primary layer (1) to the layer thickness of the tertiary layer (3) has a ratio of 10 to 14 to 14 to 16. Multi-layer composite according to one of the preceding claims, characterized in that the polyamide of the third material is selected from a group consisting of polyamide-612 (PA612), polyamide-666 (PA666), polyamide-6 (PA6), polyamide-12 (PA12) , Polyamide-66/610 (PA66 / 610), polyamide-66/612 (PA66 / 612) and polyamide-46/6 (PA46 / 6), the polyamides mentioned preferably each having an additive. Multilayer composite according to one of the preceding claims, characterized in that the tertiary layer (3) has a first tertiary part layer (3a) and a second tertiary part layer (3b), the first tertiary part layer (3a) being made from a first variation of the third material, in particular from polyamide 6 (PA6), and the second tertiary layer (3b) consists of a second variation of the third material, in particular of polyamide-612 (PA612). Multi-layer composite according to one of the preceding claims, characterized in that the secondary layer has a first secondary part layer (2a), a second secondary part layer (2b) and a third secondary part layer (2c), the first secondary part layer (2a) made of the second material or a first Variation of the second material, the second secondary layer (2b) comprises an ethylene-vinyl alcohol copolymer (EVOH) and the third secondary layer (2c) consists of the second material or a second variation of the second material. Multilayer composite according to one of the preceding claims, characterized in that at least one of the layers of the multilayer composite (12) has reinforcing fibers (15) and / or the multilayer composite (12) between the primary layer (1) and the secondary layer (2) and / or between the Secondary layer (2) and the tertiary layer (3) has a fabric layer (16) made of reinforcing fibers. Fluid line (11) made of a multi-layer composite (12), in particular a multi-layer composite (12) according to one or more of the preceding claims, wherein the multi-layer composite (12) is a primary layer (1) made of a partially crystalline isotactic homo-polypropylene, a on the primary layer (1) following secondary layer (2) made of a second material having an adhesion promoter and on the secondary layer (2) following tertiary layer (3) made of a third material having a polyamide, the first material in addition to the homo-polypropylene an anti-oxidant with a proportion of at least 0.05% to a maximum of 0.4%, based on the total mass of the first material. Fluid line after Claim 8 , characterized in that the fluid line (11) is designed as a corrugated fluid pipe. Fluid line according to one of the preceding claims, characterized in that the fluid line (11) has a fluid line area (22a) in which a cross-sectional adjustment element for adjusting a flow cross-section of the fluid line (11), in particular a check valve (23), a control valve or a thermostat ( 30) is arranged. Fluid line according to one of the preceding claims, characterized in that the fluid line (11) has a fluid line outer layer (17) which is designed as a flame protection layer, as an abrasion protection layer and / or as a thermal insulation layer. Fluid line according to one of the preceding claims, characterized in that the fluid line outer layer (17) is an optimized thermoplastic elastomer (TPE) or a functionally optimized thermoplastic polyurethane (TPU) or a blend of the homo-polypropylene and a thermoplastic elastomer (TPE), such as, for example Ethylene propylene diene rubber (EPDM), or consists of.

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