Barrier Layer for Hoses

Abstract

The invention relates to a hose having at least one barrier layer inner layer and an outer layer, wherein the barrier layer is obtainable by extrusion of a mixture comprising a) at least one thermoplastic fluoropolymer, b) at least one fluororubber and a crosslinking agent and/or at least one fluororubber elastomer and c) at least one carbon filler selected from carbon black, in particular conductivity carbon black, graphene, carbon nanofillers, in particular carbon nanotubes, carbon nanohorns, or a combination thereof in an amount of 0.05% by weight to 20% by weight of the carbon filler(s), or irradiated PTFE, and vulcanization. The hose exhibits a high fuel, diesel and oil stability and dynamic capability.

Claims

1.-15. (canceled)

16. A hose comprising at least one barrier layer and an outer layer, wherein the barrier layer is obtainable by extrusion of a mixture comprising: a) at least one thermoplastic fluoropolymer, b) at least one fluororubber and a crosslinking agent and/or at least one fluororubber elastomer; and, c) at least one carbon filler selected from carbon black; wherein the mixture contains from 0.05% to 20% by weight of the at least one carbon filler.

17. The hose as claimed in claim 16, wherein the at least one carbon filler is selected from the group consisting of conductivity carbon black, graphene, carbon nanotubes, carbon nanohorns, and any combination thereof.

18. The hose as claimed in claim 16, wherein the at least one carbon filler is conductivity carbon black, and the mixture contains 1% to 20% by weight, of the conductivity carbon black.

19. The hose as claimed in claim 18, wherein the at least one carbon filler is conductivity carbon black, and the mixture contains 2% to 10% by weight, of the conductivity carbon black.

20. The hose as claimed in claim 19, wherein the at least one carbon filler is conductivity carbon black, and the mixture contains 3% to 9% by weight, of the conductivity carbon black.

21. The hose as claimed in claim 16, wherein the at least one carbon filler is selected from the group consisting of graphene, carbon nanofillers, and a combination thereof, and the mixture contains from 0.05% to 10% by weight, of the at least one carbon filler.

22. The hose as claimed in claim 21, wherein the at least one carbon filler is selected from the group consisting of graphene, carbon nanofillers, and a combination thereof, and the mixture contains from 0.2% to 7% by weight, of the at least one carbon filler.

23. The hose as claimed in claim 22, wherein the at least one carbon filler is selected from the group consisting of graphene, carbon nanofillers, and a combination thereof, and the mixture contains from 0.2% to 5% by weight, of the at least one carbon filler

24. The hose as claimed in claim 16, wherein the barrier layer is not meltable.

25. The hose as claimed in claim 16, wherein the mixture further comprises irradiated polytetrafluoroethylene (PTFE).

26. The hose as claimed in claim 16, wherein at least one interlayer is arranged between the barrier layer and the outer layer.

27. The hose as claimed in claim 26, wherein the at least one interlayer comprises at least one member of the group consisting of vulcanizate of acrylonitrile-butadiene rubber (NBR), a vulcanizate of ethylene oxide-epichlorohydrin rubber (ECO) and/or bisphenol-crosslinked fluororubber (FKM), aminically crosslinked FKM and peroxidically crosslinked FKM.

28. The hose as claimed in claim 16, wherein the mixture contains 60% by weight to 90% by weight of thermoplastic fluoropolymer and 10% by weight to 40% by weight of fluororubber and/or fluororubber elastomer.

29. The hose as claimed in claim 16, wherein arranged between the barrier layer and the outer layer is at least one elastomeric interlayer, comprising ethylene oxide-epichlorohydrin rubber (ECO), ethylene-acrylate rubber (AEM), acrylate rubber (ACM), chlorinated polyethylene rubber (CM) and/or hydrogenated acrylonitrile-butadiene rubber (HNBR); wherein a strength member comprising p-aramid, m-aramid, polyphenylene sulfide (PPS) and/or polyethylene terephthalate (PET), is arranged between the at least one elastomeric interlayer and the outer layer; and, wherein the outer layer comprises ethylene oxide-epichlorohydrin rubber (ECO), ethylene-acrylate rubber (AEM), acrylate rubber (ACM), chlorinated polyethylene rubber (CM) and/or hydrogenated acrylonitrile-butadiene rubber (HNBR).

30. The hose as claimed in claim 29, wherein the at least one elastomeric interlayer is two elastomeric interlayers, wherein the barrier layer contains fluorothermoplastic vulcanizates (FTPV), wherein an inner elastomeric interlayer contains fluororubber (FKM), wherein an outer elastomeric interlayer contains ethylene oxide-epichlorohydrin rubber (ECO), wherein the strength member contains m-aramid and wherein the outer layer contains acrylate rubber (ACM).

31. The hose as claimed in claim 16, wherein each layer has a resistance of <109 ohms measured according to DIN IEC 60093:1993-12 and/or DIN IEC 167 1994-10.

32. The hose as claimed in claim 29, wherein the hose is an air-conducting hose, a fuel hose or an oil hose.

33. A process for producing a hose comprising at least one barrier layer inner layer and an outer layer, wherein the process comprises: I) extruding a mixture comprising: a) at least one thermoplastic fluoropolymer; b) at least one fluororubber and a crosslinking agent and/or at least one fluororubber elastomer; and, c) at least one carbon filler selected from carbon black, conductivity carbon black, graphene, carbon nanofiller, or a combination thereof, and/or irradiated PTFE; to form the barrier layer; II) applying the outer layer over the barrier layer; and, III) vulcanizing of the formed hose construction.

34. The process as claimed in claim 33, wherein the mixture is extruded at a temperature in the range from 170 C. to 300 C.

35. A hose comprising at least one barrier layer inner layer and an outer layer, wherein the barrier layer is obtainable by extrusion of a mixture comprising: a) at least one thermoplastic fluoropolymer; b) at least one fluororubber and a crosslinking agent and/or at least one fluororubber elastomer; and, c) irradiated polytetrafluoroethylene (PTFE).

Description

[0081] The invention will now be more particularly elucidated on the basis of an exemplary embodiment with reference to the figures. The figures show:

[0082] FIG. 1 an inventive hose which additionally comprises an optional interlayer and an optional strength member.

[0083] FIG. 2 Image of a melting test on the inventive barrier layer/inner layer after extrusion and before vulcanization.

[0084] FIG. 3 Image of a melting test carried out on a reference.

[0085] FIG. 4 results of a dynamic mechanical analysis (DMA) on the inventive barrier layer/inner layer after extrusion and before vulcanization.

[0086] FIG. 5 results of the dynamic mechanical analysis (DMA) on a reference.

[0087] FIG. 6 results of the dynamic mechanical analyses (DMA) on all samples analyzed.

[0088] FIG. 1 shows an inventive hose comprising the following exemplary material concept:

[0089] The barrier layer/inner layer 1 was obtained by extrusion of a mixture containing Daikin FTPV SV-1020, a mixture of thermoplastic fluoropolymers and fluororubbers including a crosslinking agent, and 7% by weight, based on the total weight of the mixture, of Ketjenblack EC300J, a carbon black, as the carbon filler, at 260 C. and subsequent vulcanization of the pictured hose assembly at 170 C.

[0090] The barrier layer/inner layer 1 is delimited by the interlayer 2. The interlayer 2 is formed by a vulcanizate of ethylene oxide-epichlorohydrin rubber (ECO) and also serves as an adhesion layer between the inner layer 1 and the strength member 3. The strength member 3 is formed from m-aramid and is delimited by the outer layer 4. The outer layer 4 contains acrylate rubber (ACM).

[0091] A melting test was performed on the barrier layer/inner layer after extrusion and before vulcanization. The barrier layer/inner layer was not meltable even at 280 C. after extrusion and before vulcanization (FIG. 2). Daikin FTPV SV-1020 pellets without carbon filler served as a reference. This reference was molten at 280 C. (FIG. 3).

[0092] A dynamic mechanical analysis (DMA) was carried out on the barrier layer/inner layer after extrusion and before vulcanization. The dynamic mechanical analysis (DMA) was carried out using a Mettler Toledo DMA/SDTA 861. Round specimens were stamped out and installed in the shear specimen holder under prestress. A temperature scan in the range from 140 C. to 300 C. at 10 Hz was selected as the analysis program, maximum force amplitude 10 N, maximum displacement amplitude 2 m, heating rate 2 C./min.

[0093] FIG. 4 shows the analysis profile of the inventive barrier layer/inner layer after extrusion and before vulcanization. The upper section shows the profile of the storage modulus G and the loss module G in each case in duplicate. The lower section shows the corresponding profile of tan delta for each of the two specimens. The value for tan delta remains below 1.0 even at temperatures above 220 C.

[0094] FIG. 5 shows the profile for two corresponding specimens but without carbon filler. A value for tan delta of more than 1.0 is achieved at temperatures above 220 C.

[0095] FIG. 6 shows the analysis profiles for various inventive barrier layers/inner layers after extrusion and before vulcanization and also for the noninventive specimens without carbon filler in a graphene.

[0096] In contrast to barrier layers produced in corresponding fashion but containing no carbon filler it was surprisingly found in the inventive barrier layers/inner layers after extrusion and before vulcanization that addition of the carbon filler causes the barrier layer to lose its thermoplastic properties. This verifies the dynamic mechanical analysis (DMA). While DMA of a barrier layer produced without the addition of carbon filler results in the typical image for a thermoplastic vulcanizate (TPV), also referred to as a thermoplastic elastomer, melting of the thermoplastic cannot be observed in DMA of the inventive barrier layer produced with carbon filler: The storage modulus G is not only significantly higher than that of the unfilled reference, but it must also be noted that the storage modulus and loss modulus G change identically at temperatures above 230 C. This is shown even more clearly by tan delta=G/G. At 220 C. the unfilled material shows a tan delta>1 (G>G) while the filled material shows a tan delta of 0.7. According to the literature (for example Wikipedia: https://de.wikipedia.org/wikiNiskoelastizit % C3% A4t) melting of the reference results in a liquid/melt while the filled material is a solid.

LIST OF REFERENCE NUMERALS

[0097] 1 Barrier layer/inner layer [0098] 2 Intermediate layer [0099] 3 Strength member [0100] 4 Outer layer