Abstract
The present invention relates to a method for producing a wiper blade element (10) for a wiper blade and/or a wiper blade having a wiper blade element (10), in particular for a windscreen wiper. In order to provide simple and economical wiper blade elements and wiper blades having excellent properties, in particular having high wiping quality, high abrasion resistance, a high degree of friction reduction and miming noise reduction and a long service life, in said method a particle layer (12) is applied to an elastomer substrate (11), the elastomer substrate (11) is vulcanised with the particle layer (12) deposited thereon, and, after vulcanisation, a friction-reducing material (13) is applied to the particle layer (12). The invention further relates to a wiper blade element and wiper blade produced in such a way.
Claims
1. A process for the production of a wiper rubber (10) for a wiper blade and/or of a wiper blade with a wiper rubber (10), the process comprising applying a particle layer (12) to an elastomer substrate (11), vulcanizing the elastomer substrate (11) with the particle layer (12) applied thereon, and after vulcanization, applying a friction-reducing material (13) to the particle layer (12).
2. The process as claimed in claim 1, where the particle layer (12) is a particle monolayer.
3. The process as claimed in claim 1, where the particle layer (12) is configured in the form of a non-continuous layer.
4. The process as claimed in claim 1, where the friction-reducing material (13) is applied between particles of the particle layer (12) and/or on surface regions of the elastomer substrate (11) which are accessible between particles of the particle layer (12).
5. The process as claimed in claim 1, where the friction-reducing material (13) completely fills interstices between particles of the particle layer (12) and/or converts the particle layer (12) originally configured in the form of a non-continuous layer to a continuous layer.
6. The process as claimed in claim 1, where the friction-reducing material (13) forms, above the particle layer (12), in particular above the particle layer (12) rendered continuous by the friction-reducing material (13), a friction-reducing layer (13) that is in particular continuous.
7. The process as claimed in claim 1, where the particle layer (12) is configured by application of a granulate to the elastomer substrate (11).
8. The process as claimed in claim 1, where the particle layer (12) is applied by powder coating.
9. The process as claimed in claim 1, where the particle layer (12) comprises polymer particles, in particular with a molar mass of ≥1.Math.10.sup.6 g/mol.
10. The process as claimed in claim 1, where the particle layer (12) comprises polymer particles which comprise and, respectively, are formed from polyethylene with a high molecular weight and/or polyethylene with an ultrahigh molecular weight and/or polyethylene and/or fluorinated polyethylene, in particular polytetrafluoroethylene, and/or polyphenyl ether and/or a perfluoroalkoxy polymer and/or polycarbonate and/or polyoxymethylene and/or polyacrylate and/or polyurethane.
11. The process as claimed in claim 1, where the friction-reducing material (13) and/or the friction-reducing layer (13) is applied by spray coating or by powder coating.
12. The process as claimed in claim 1, where the friction-reducing material and, respectively, the friction-reducing layer comprise friction-reducing sacrificial-material particles, in particular solid-lubricant particles.
13. The process as claimed in claim 1, where the friction-reducing material (13) and/or the friction-reducing layer (13) comprises graphite particles and/or polytetrafluoroethylene particles and/or polyethylene particles and/or polypropylene particles and/or molybdenum disulfide particles and/or tungsten disulfide particles.
14. The process as claimed in claim 1, where the friction-reducing material (13) and/or the friction-reducing layer (13) moreover comprise(s) at least one binder, in particular at least one poly(meth)acrylate and/or at least one polyurethane and/or at least one polystyrene and/or at least one epoxy resin and/or at least one polyester and/or at least one polyether and/or at least one copolymer and/or block copolymer thereof.
15. The process as claimed in claim 1, where the friction-reducing material (13) and/or the friction-reducing layer (13) moreover comprise(s) at least one crosslinking agent, in particular a crosslinking agent that is appropriate for the at least one binder.
16. The process as claimed in claim 1, where, after the application of the friction-reducing material (13), the friction-reducing material (13) and, respectively, the friction-reducing layer (13) and/or the particle layer (12) are dried and/or hardened.
17. The process as claimed in claim 1, where, before the application of the friction-reducing material (13), in particular after vulcanization and before the application of the friction-reducing material (13), the particle layer (12) and/or surface regions of the elastomer substrate (11) which are accessible between particles of the particle layer (12) is/are pretreated by a plasma treatment and/or by a chemical surface-functionalization.
18. The process as claimed in claim 1, where the elastomer substrate (11) is extruded from an elastomer material and, respectively, the particle layer (12) is applied to an extruded elastomer substrate (11).
19. The process as claimed in claim 1, where the elastomer substrate (11) comprises ethylene-propylene-diene rubber and/or ethylene-propylene rubber and/or chloroprene rubber and/or natural rubber.
20. The process as claimed in claim 1, where the elastomer substrate (11) is provided in the form of a double wiper rubber profile, where, after vulcanization and before or after, in particular after, the application of the friction-reducing material (13), the elastomer substrate (11) in the form of the wiper rubber double profile is divided, in particular divided by cutting, to give wiper rubbers, in particular in the form of single wiper rubber profiles.
21-22. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0065] Further advantages and advantageous specific forms of the subject matter of the invention are illustrated by the drawings and the working example and are explained in the description below. It should be noted here that the drawings and the working example are merely descriptive and are not intended in any way to restrict the invention.
[0066] FIG. 1 shows a flow diagram to illustrate an embodiment of the process of the invention;
[0067] FIG. 2 shows diagrammatic perspective views to illustrate a specific form of the embodiment shown in FIG. 1 for the process of the invention by means of an elastomer substrate in the form of a double wiper rubber profile which is divided to give wiper rubbers in the form of single wiper rubber profiles;
[0068] FIG. 3 shows a flow diagram to illustrate a first specific form of the embodiments shown in FIGS. 1 and 2 for the process of the invention;
[0069] FIG. 4 shows a flow diagram to illustrate a second specific form of the embodiment shown in FIG. 1 for the process of the invention;
[0070] FIG. 5 shows a flow diagram to illustrate a third specific form of the embodiments shown in FIGS. 1 and 2 for the process of the invention;
[0071] FIG. 6 shows a flow diagram to illustrate a fourth specific form of the embodiments shown in FIGS. 1 and 2 for the process of the invention;
[0072] FIG. 7 shows a diagrammatic cross section through a wiper rubber produced in an embodiment of the process of the invention, and
[0073] FIG. 8 shows an electron micrograph of a cross-sectional area of a working example of a wiper rubber produced in an embodiment of a process of the invention.
DETAILED DESCRIPTION
[0074] FIG. 1 shows a flow diagram to illustrate an embodiment of the process of the invention for the production of a wiper rubber for a wiper blade and/or of a wiper blade with a wiper rubber.
[0075] FIG. 1 illustrates that a particle layer is applied here in a process step B1) to an elastomer substrate, for example based on ethylene-propylene-diene rubber and/or ethylene-propylene rubber and/or chloroprene rubber and/or natural rubber. This can be achieved by way of example by means of powder coating. The particle layer here can in particular be configured in the form of a non-continuous particle monolayer. The particle layer here can in particular comprise polymer particles which comprise and, respectively, are formed from polyethylene with a high molecular weight and/or polyethylene with an ultrahigh molecular weight and/or polyethylene and/or fluorinated polyethylene, in particular polytetrafluoroethylene, and/or polyphenyl ether and/or a perfluoroalkoxy polymer and/or polycarbonate and/or polyoxymethylene and/or polyacrylate and/or polyurethane.
[0076] FIG. 1 moreover illustrates that, in a process step V) downstream of the process step B1), the elastomer substrate with the particle layer applied thereon is vulcanized. The vulcanization can be achieved by a heat treatment, for example in a salt bath, and/or optionally by a hot-air treatment or microwave treatment, in particular in a salt bath. It is thus possible to achieve strong attachment of the particles of the particle layer to the elastomer substrate.
[0077] FIG. 1 furthermore illustrates that, after vulcanization, in a process step B2) downstream of the process step V), a friction-reducing material is applied to the particle layer. This can be achieved by way of example by spray coating or by powder coating. The friction-reducing material here can in particular comprise friction-reducing sacrificial-material particles, for example solid-lubricant particles, for example graphite particles and/or polytetrafluoroethylene particles and/or polyethylene particles and/or polypropylene particles and/or molybdenum disulfide particles and/or tungsten disulfide particles. The friction-reducing material here can in particular be applied between particles of the particle layer and/or on surface regions of the elastomer substrate which are accessible between particles of the non-continuous particle monolayer. The friction-reducing material can completely fill interstices between particles of the particle layer and/or can convert the particle layer originally configured in the form of a non-continuous layer to a continuous layer. Furthermore, the friction-reducing material can also form, above the particle layer, in particular above the particle layer rendered continuous by the friction-reducing material, a friction-reducing layer that is continuous.
[0078] FIG. 2 illustrates, in diagrammatic perspective views, a form of the embodiment shown in FIG. 1 for the process of the invention, where the elastomer substrate 11 is provided in the form of a, for example extruded, double wiper rubber profile. The particle layer 12 is applied to the elastomer substrate 11 in the form of the double wiper rubber profile in process step B1), and the elastomer substrate 11 with the particle layer 12 applied thereon is vulcanized in process step V) (not depicted in FIG. 2). FIG. 2 shows that, after vulcanization, the friction-reducing material 13 is applied in process step B2) by spray coating to the particle layer 12 and in particular between particles of the particle layer 12 and/or on surface regions of the elastomer substrate 11 which are accessible between particles of the particle layer. FIG. 2 shows that the elastomer substrate in the form of the double wiper rubber profile is then, in a process step S), divided, in particular divided by cutting, to give wiper rubbers in the form of single wiper rubber profiles.
[0079] FIGS. 3 to 6 illustrate that, in the context of the specific forms shown therein of the embodiment shown in FIG. 1 and/or 2 for the process of the invention, the elastomer substrate is extruded in a process step E) upstream of process step B1), in particular in the form of a double wiper rubber profile.
[0080] In the first specific form illustrated in FIG. 3—by analogy with the specific form shown in FIG. 2—the particle layer is then applied to the elastomer substrate in the form of the double wiper rubber profile in process step B1), and the elastomer substrate with the particle layer applied thereto is vulcanized in process step V). After vulcanization, the friction-reducing material is then applied in process step B2), for example by spray coating, to the particle layer and in particular between particles of the particle layer and/or to surface regions of the elastomer substrate which are accessible between particles of the particle layer. After the application of the friction-reducing material in process step B2, the elastomer substrate in the form of the double wiper rubber profile is then, in a process step S), divided, for example divided by cutting, to give wiper rubbers in the form of single wiper rubber profiles. It is thus advantageously possible to achieve a particularly uniform layer level at the cut edge, and thus particularly high wiping quality.
[0081] The second specific form, illustrated in FIG. 4, differs from the first specific form illustrated in FIG. 3 in essence in that the elastomer substrate in the form of the double wiper rubber profile is divided in process step S), for example divided by cutting, after vulcanization in process step V) and before application of the friction-reducing material in process step B2), to give wiper rubbers, in particular in the form of single wiper rubber profiles.
[0082] The third specific form, illustrated in FIG. 5, differs from the first specific form illustrated in FIG. 3 in essence in that in a process step P) downstream of process step V) and upstream of process step B2) the particle layer and/or surface regions of the elastomer substrate which are accessible between particles of the particle layer is pretreated by a plasma treatment and/or by a chemical surface-functionalization, before application of the friction-reducing material. It is thus possible to achieve increased adhesion and/or a covalent chemical attachment of the friction-reducing material and, respectively, of the friction-reducing layer on the elastomer substrate and/or on the particle layer, and by way of example to lengthen the lifetime of the wiper rubber.
[0083] The fourth specific form, illustrated in FIG. 6, differs from the first specific form illustrated in FIG. 3 in essence in that the friction-reducing material and/or the particle layer is dried and/or hardened in a process step H) downstream of process step B2) and upstream of process step S). The robustness of the friction-reducing material and/or of the particle layer can thus be increased and in particular adjusted in targeted manner and by way of example optimized not only in respect of a good reduction of friction but also in respect of a long lifetime of the wiper rubber.
[0084] FIG. 7 shows a diagrammatic cross section through an embodiment of a wiper rubber produced in a process of the invention. The wiper-rubber embodiment shown in FIG. 7 can in particular have been produced by first applying a non-continuous particle monolayer 12 to an elastomer substrate 11, then vulcanizing the elastomer substrate 11 with the particle monolayer 12 applied thereon and, after vulcanization, applying a friction-reducing material 13 to the particle monolayer 12 in a manner such that the friction-reducing material 13 is applied not only between particles of the particle monolayer 12 but also on surface regions of the elastomer substrate 11 which are accessible between particles of the particle monolayer 12, and completely fills interstices between particles of the particle monolayer 12, and also forms a continuous layer above the particle monolayer 12. The broken horizontal line in FIG. 7 indicates that the particle monolayer 12 originally configured in the form of a non-continuous layer is thus converted to a continuous layer in the form of a combination layer composed of the particle monolayer 12 and of the friction-reducing material 13, and that the friction-reducing material 13 additionally also forms a continuous layer 13 above the particle (combination) monolayer 12 rendered continuous by the friction-reducing material 13. FIG. 7 moreover indicates that vulcanization of the elastomer substrate together with the particle monolayer 12 applied thereon can be discernible for example via slight deformation of the particles 12 and/or slight molding of the particles 12 onto the elastomer substrate 11. Such cross-sectional views can be produced under practical conditions by means of electron microscopy on cross-sectional areas.
[0085] FIG. 8 shows an electron micrograph of a cross-sectional area of a working example of a wiper rubber produced in an embodiment of a process of the invention.
[0086] For the purposes of the working example, a wiper rubber was produced in an embodiment of a process of the invention by applying an originally non-continuous UHMW-particle monolayer 12 composed of polyethylene polymer particles with an ultrahigh molecular weight (UHMWPE) to an elastomer substrate 11 composed of ethylene-propylene-diene rubber (EPDM) by powder coating by means of a fluidized layer, and vulcanizing the elastomer substrate 11 with the UHMW-particle monolayer 12 applied thereon. After vulcanization, graphite 13 was then applied by water-based spray coating to the UHMW-particle monolayer 12, and specifically in a manner such that the graphite 13 was applied not only between UHMW particles of the UHMW-particle monolayer 12 but also on surface regions of the elastomer substrate 11 which are accessible between UHMW particles of the UHMW-particle monolayer 12, and completely filled the interstices between UHMW particles of the UHMW-particle monolayer 12, and converted the UHMW-particle monolayer 12, which was originally configured in the form of a non-continuous layer, to a continuous layer in the form of an UHMW-particle-graphite combination layer 12, 13, and furthermore also formed a continuous graphite layer 13 above the UHMW-particle monolayer 12, in particular above the UHMW-particle monolayer 12 and, respectively, UHMW-particle-graphite combination layer 12, 13 rendered continuous by the graphite 13.
[0087] The UHMW particle 12 depicted on the left in the foreground in FIG. 8 illustrates that vulcanization of the elastomer substrate 11 together with the particle monolayer 12 applied thereon can be discernible by means of electron microscopy of cross-sectional areas, for example via slight deformation of particles 12 and/or slight molding of particles 12 onto the elastomer substrate 11.
