DE102012201899A1 - Wiper rubber with surface structuring and highly hydrophobic coating - Google Patents

Abstract

The present invention relates to a squeegee 10 for a windscreen wiper, which has a wiper rubber base body 1. In order to improve the water-repellent properties and their resistance, in particular under a vertical contact force, the surface of the wiper rubber base body 1 in at least one section of the wiper rubber base body 1 has a surface structuring with elevations 2 in the micrometer range, wherein a highly hydrophobic layer 3 is formed between the elevations 2 and wherein the elevations 2 project beyond the highly hydrophobic layer 3, which is formed between the elevations 2. Moreover, the present invention relates to a wiper blade comprising such a squeegee, and a method for producing a squeegee.

Description

The present invention relates to a squeegee and a wiper blade for a windshield wiper and a method for producing a squeegee.

State of the art

Wiper blades for windshield wipers are usually designed to adapt to the contour of a glass pane of a vehicle and to remain flexible at different temperatures.

However, compared to other materials, such as glass or plastic, elastomers have high coefficients of sliding friction, so in order to cause horizontal movement of a wiper blade mounted on a vehicle, a multiple of the vertical contact force on the squeegee must be used.

The publication WO 2008/113624 A1 describes a squeegee made of an elastomeric material which has a surface structuring of elevations and / or depressions in the micrometer range.

The publication US 6,982,112 describes a composite laminate comprising a rubber substrate and a polyolefin coating applied to the rubber substrate.

Disclosure of the invention

The present invention is a wiper blade for a wiper blade, in particular for a windshield wiper, for example for a motor vehicle, which comprises a wiper base rubber. In this case, the surface of the wiper rubber base body in at least a portion of the wiper rubber base body on a surface structuring with elevations in the micrometer range. According to the invention, a highly hydrophobic layer is formed between the elevations. In particular, the surveys are superior to the highly hydrophobic layer formed between the surveys.

Surveys in the micrometer range can be understood in particular to be bodies whose height on average is ≦ 100 μm, in particular ≦ 50 μm. For example, the height of the elevations may be, for example, on average between ≥ 2 μm and ≦ 100 μm or ≦ 50 μm. For example, the surface structuring may have elevations whose mean height is ≦ 20 μm and, for example, between ≥ 2 μm or ≥ 5 μm to ≦ 20 μm. For example, the elevations can have, for example, on average a distance of ≥ 5 μm to ≦ 50 μm. The deeper areas between the elevations can occupy a large part of the surface of the surface structuring.

The bumps advantageously act as spacers and thereby reduce the dynamic friction between the squeegee and the glass sheet. In addition, the elevations produce a lotus effect, which under static conditions has a water-repellent effect.

The lotus effect conventionally refers to an effect which has been elucidated on the basis of lotus plants. Lotus plants have a surface structuring in the micrometer, which causes the surface is superhydrophobic, so that drops of water approximately assume a spherical shape and with respect to the surface, for example, a contact angle of ≥ 150 ° and can roll off the surface. In this case, the water droplets usually contact only the raised areas of the surface structuring, wherein the deeper areas may be filled with air, which normally prevents wetting of the deeper areas with water.

In the context of the present invention, however, it has been found that under dynamic conditions, such as occur during the wiping cycle of a wiper blade mounted on a windshield wiper, the contact force acting vertically on the wiper blade and / or the friction forces between the wiper blade and the wheel lead to a decrease in the number of wiper rubbers. Effect can lead, so that under dynamic conditions, based on the Lotus effect water repellent properties of the surface structure can decrease and water can penetrate into the deeper areas of the surface structuring. This can lead to a film of water between the squeegee and the disc is formed, which can reduce the static frictional force so strong that the turning of the wiper blade of the wiper blade at the reversal point of the windscreen wiper, the so-called flip-over, delayed or possibly even can not be done at all. This effect can be increased at low temperatures, for example, 2 ° C, because even more water can accumulate between the wiper lip and the disc due to the dew point and a low evaporation rate during subsequent wiping cycles.

In the context of the present invention, it has been found that the formation of a water film increasingly occurs when the areas between the elevations, ie the deeper areas of the surface structuring, are only slightly highly hydrophobic or even hydrophilic and / or tend to absorb water.

In the context of the present invention, it has also been found that the fact that the areas between the elevations, ie the deep areas of the surface structuring are covered with an additional highly hydrophobic layer, the formation of a water film under dynamic conditions during wiping, in particular under a vertical Contact force and / or friction can be avoided. In particular, the highly hydrophobic layer leads to strongly water-repellent properties of the areas between the elevations, ie the deep areas of the surface structuring, and prevents water wetting of the deeper areas of the surface structuring and absorption of water by the material of the wiper rubber base body.

The fact that the surveys dominate the formed between the surveys highly hydrophobic layer, on the one hand, the friction can be lowered and based on the lotus effect highly water-repellent properties can be achieved. In addition, this can ensure that the squeegee runs during the wiping on the surveys, so that the formed in the deeper areas, an additional water-repellent effect causing, highly hydrophobic layer is protected against downforce or wear. This in turn advantageously enables the highly hydrophobic layer to be formed from materials such as silicone oil or vulcanized silicones, which are otherwise susceptible to abrasion or abrasion, that is without the protective protuberances.

As a result of the elevations of the surface structuring and the highly hydrophobic layer formed between the elevations and projecting from the elevations, it is advantageously possible to provide a wiper rubber which has strongly water-repellent properties even under dynamic conditions during wiping, in particular under a vertical contact force and / or friction. and has a low friction and is particularly durable or wear-resistant

The hydrophobicity of a surface, that is the measure of the degree of hydrophobicity, may be expressed in terms of the contact angle, which is the angle that a drop of liquid forms on the surface of a solid to that surface. At contact angles of about 90 °, a surface can be referred to in particular as low hydrophobic. At contact angles ≥ 120 °, a surface can be referred to in particular as highly hydrophobic. At contact angles ≥ 150 °, for example by about 160 °, a surface can be described not only as highly hydrophobic but in particular even as superhydrophobic.

The surface of the highly hydrophobic layer may in particular have a contact angle of ≥ 120 °, for example of ≥ 125 °, relative to water.

The highly hydrophobic layer, for example, in the areas between the surveys, a layer thickness of ≤ 5 microns, for example, ≤ 2 microns or ≤ 1 microns have.

In the context of a further embodiment, the highly hydrophobic layer is substantially continuous. In this case, it can be understood to mean essentially continuous that the highly hydrophobic layer can be interrupted at the locations where the elevations are formed. However, it is also possible that the highly hydrophobic layer covers the bumps partially or completely. For example, it is possible for the highly hydrophobic layer not to cover the highest area of the elevations or at least to cover it with a smaller layer thickness than the areas between the elevations.

Preferably, the highly hydrophobic layer is formed of an elastic material. By elastic materials advantageously a better wiping quality can be achieved than by hard materials.

Within the scope of a further embodiment, the highly hydrophobic layer comprises at least one silicon-containing compound, in particular at least one silicon-containing polymer.

In another embodiment, the highly hydrophobic layer comprises at least one silicon-containing compound selected from the group consisting of silicone oils, polysiloxanes, polysiloxane copolymers, polysilanes, polysilane copolymers, and combinations thereof.

In a further embodiment, the highly hydrophobic layer comprises at least one crosslinked and / or vulcanized silicon-containing polymer, in particular selected from the group consisting of crosslinked polysiloxanes, crosslinked polysiloxane copolymers, crosslinked polysilanes, crosslinked polysilane copolymers and combinations thereof.

In particular, a crosslinked silicon-containing polymer can be prepared by reacting one or more first components selected from the group consisting of linear and / or branched polysiloxanes, polysilanes and (co) polymers which are attached to one or more ends and / or to the polymer chains ( total) at least two functional group, with one or more second, especially multifunctional crosslinking, components whose functional groups can react with the functional groups of the first component / s. It is possible as (co) polymers to use silicon-containing or silicon-free polymers, in which respect a silicon-free polymer is used, for example, at least one first and / or second silicon-containing component is used. In particular, the second component (s) may be multifunctional crosslinking silicon-containing compounds, such as multifunctional crosslinking silanes.

The functional groups of the first and second component (s) may be selected, for example, depending on one another, from the group consisting of silanol groups, acetoxy groups, alkoxy groups, oxime groups, vinyl groups, hydride groups, Epoxy groups, thiol groups and amino groups.

In the context of one embodiment, the at least one crosslinked silicon-containing polymer is produced by means of a condensation reaction.

The functional groups of the first component (s) may be, for example, silanol groups (Si-OH). The functional groups of the second component (s) can be selected, for example, from the group consisting of acetoxy groups, alkoxy groups and oxime groups. Conversely, it is also possible that the functional groups of the first component (s) are acetoxy, alkoxy and / or oxime groups and the functional groups of the second component (s) are silanol groups. The silanol group can advantageously condense with many multifunctional crosslinking components, in particular silanes which have, for example, acetoxy, alkoxy and / or oxime groups as functional groups.

In another embodiment, the at least one crosslinked silicon-containing polymer is prepared by means of an addition reaction, for example a silylation reaction, in particular a hydrosilylation reaction.

The addition reaction can be based for example on the reaction of a hydride group, in particular Si-H, with a vinyl group. The reaction can be catalyzed in particular by platinum group metal complexes. For example, a vinyl-functionalized, especially vinyl-terminated, polydimethylsiloxane can be crosslinked with a hydride-containing precursor, for example with a plurality of hydride groups, such as polymethylhydrosiloxane.

In a further embodiment, at least one, in particular reactively functionalized, for example epoxy-functionalized, silicone derivative is used to form the highly hydrophobic layer.

In a further embodiment, at least one, in particular functionalized, fluorinated compound is used to form the highly hydrophobic layer.

In another embodiment, the highly hydrophobic layer is based on or is the highly hydrophobic layer made of at least one compound selected from the group consisting of silicone oils, vinyl-functionalized polysiloxanes, epoxy-functionalized polysiloxanes, thiol-functionalized polysiloxanes, amino-functionalized polysiloxanes, alkoxysilanes, especially organoalkoxysilanes and or fluoro-functionalized organoalkoxysilanes, for example, their organic group comprises an, especially reactive, epoxy group, and combinations thereof. The highly hydrophobic layer may in particular be based on or prepared from at least one compound selected from the group consisting of silicone oils, vinyl-functionalized polydimethylsiloxanes, epoxy functionalized polydimethylsiloxanes, thiol-functionalized polydimethylsiloxanes, amino-functionalized polydimethylsiloxanes, alkoxysilanes, in particular organoalkoxysilanes and / or fluorine-functionalized organoalkoxysilanes, for example the organic group of which comprises an especially reactive epoxy group, and combinations thereof.

In the context of a further embodiment, the elevations are formed by, for example, substantially spherical particles bounded in particular to the wiper rubber base body surface. A formation of the elevations by particles has the advantage that the surface structuring can be produced in a particularly simple manner.

The particles may have an average particle size in the micrometer range, in particular between ≥ 2 μm and ≦ 20 μm, for example between ≥ 5 μm and ≦ 20 μm, for example of about 10 μm.

However, it is also possible to form the elevations by a different material application and / or by material removal or deepening of material areas.

The surface structuring may for example be based on a layer of particles being applied to a surface section of the wiper rubber base body. The particles can be connected in particular to the material of the wiper rubber base body. The highly hydrophobic layer can then be applied between the particles, and in particular be bonded to the material of the wiper rubber base.

In a further embodiment, the surveys are formed randomly distributed. A random distribution of the elevations can be present in particular when the elevations are formed by particles, which in turn can simplify the production of the surface structuring.

In the context of a further embodiment, the elevations are substantially spaced from each other or formed substantially not connected. This can have a particularly advantageous effect on the water-repellent properties based on the lotus effect. In this case, it can be understood in particular in particular that, for example, in the case of a formation of the elevations by randomly distributed particles, some of the randomly distributed particles can touch one another or can be connected to one another.

In another embodiment, the particles comprise at least one material selected from the group consisting of ultra-high molecular weight polyethylene (UHMW-PE), high density polyethylene (HD-PE), low density polyethylene (LD-PE), isotactic polypropylene (PP ), Polyamide (PA), polytetrafluoroethylene (PTFE), carbon black, inorganic (powdered) fillers such as silicates, metal oxides and / or metals or metal alloys, and mixtures thereof. In particular, the particles may be formed of at least one material selected from the group consisting of ultra-high molecular weight polyethylene (UHMW-PE), high density polyethylene (HD-PE), low density polyethylene (LD-PE), isotactic polypropylene (PP) , Polyamide (PA), polytetrafluoroethylene (PTFE), carbon black, inorganic (powdered) fillers such as silicates, metal oxides and / or metals or metal alloys, and mixtures thereof. For example, the particles may be selected from the group consisting of ultra high molecular weight polyethylene (UHMW-PE) particles, high density polyethylene (HDPE) particles, low density polyethylene (LD-PE) particles, isotactic polypropylene (PP) particles. , Polyamide particles (PA), polytetrafluoroethylene (PTFE) particles, carbon black particles, inorganic particles such as silicate particles, metal oxide particles and / or metal particles, and mixtures thereof. The elevations may in particular be formed by polyolefin particles, for example crystalline polyolefin particles, in particular UHMW-PE particles.

In the context of a further embodiment, the wiper rubber base body has a wiper lip section and a fastening section. Preferably, the surface of the wiper lip portion is at least partially provided with the elevations and the highly hydrophobic layer formed therebetween. In particular, a tilting web section can be formed between the wiper lip section and the fastening section, which permits tilting of the wiper lip section relative to the fastening section.

In the context of a further embodiment, the wiper lip section has two wiping edges, an end face formed between the wiping edges, and two side faces each adjacent to a wiping edge. In this case, the surfaces of the side surfaces, at least in the regions adjacent to the wiping edges, are preferably provided with the surface-structuring elevations and the highly hydrophobic layer formed therebetween. The end face can be unstructured and uncoated in particular. Advantageously, the wiping properties are not degraded, inasmuch as the end face has no surface structuring and highly hydrophobic layer. A squeegee with an unstructured and uncoated face can advantageously be made particularly easy, fast and inexpensive from a double (wiper) profile.

In a further embodiment, the wiper rubber base body comprises at least one elastomeric material or is formed therefrom. For example, the elastomeric material may be selected from the group consisting of ethylene-propylene-diene monomer rubber (EPDM), ethylene-propylene monomer rubber (EPM), chlorobutyl rubber, bromobutyl rubber, chloroprene rubber (CR), Natural rubber (NR), polyurethane rubber and combinations thereof. In particular, the wiper gum base may be polyolefin-based.

With regard to further features and advantages of the wiper rubber according to the invention, reference is hereby explicitly made to the explanations in connection with the method and wiper blade explained below and to the figures and the description of the figures.

• a) Bereitstellen eines Wischgummigrundkörpers, dessen Oberfläche in mindestens einem Abschnitt des Wischgummigrundkörpers eine Oberflächenstrukturierung mit Erhebungen im Mikrometerbereich aufweist.
• b) Beschichten des mit der Oberflächenstrukturierung versehenen Abschnitts des Wischgummigrundkörpers mit einer hochhydrophoben Schicht.

A further subject of the present invention is a process for producing a wiper rubber, in particular a wiper rubber according to the invention, which comprises the process steps:

• a) providing a wiper rubber base body, the surface of which has a surface structuring with elevations in the micrometer range in at least one section of the wiper rubber base body.
• b) coating the surface-structured portion of the wiper rubber base body with a highly hydrophobic layer.

The surface of the highly hydrophobic layer may in particular have a contact angle with respect to water of ≥ 120 °.

In particular, the coating in method step b) can take place such that the elevations project beyond the highly hydrophobic layer which is formed between the elevations.

In process step a), in particular a vulcanized or pre-vulcanized wiper rubber base body can be provided.

In one embodiment, in process step b), a silicon-containing coating liquid is applied to the section provided with the surface structuring, in particular sprayed on.

In particular, the silicon-containing coating fluid may comprise at least one silicon-containing compound or precursor selected from the group consisting of silicone oils, polysiloxanes, polysiloxane copolymers, polysilanes, polysilane copolymers, their precursors, and combinations thereof.

To avoid the liquid silicone oil is transferred to the disc, which may affect the visual wiping quality, for example in the form of smearing and / or clouding, is preferably only a very small amount of silicone oil, especially in the form of a diluted silicone oil solution or suspension in a volatile solvent, such as hexane or naphtha, applied or sprayed onto the provided with the surface structuring section.

The silicon-containing coating liquid can be designed, for example, to form a crosslinked silicone film. For this purpose, the silicon-containing coating liquid may in particular comprise a mixture of two or more components. Of the two or more components, one component may be, for example, a linear silicone having a functional group at both ends. Instead of a difunctional silicone polymer, it is also possible to use a copolymer which has functional groups on the polymer chains or it is possible to use branched silicones which have functional groups at the ends. As a further component, for example, a multifunctional, monomeric or polymeric, crosslinking component which can react with the other component.

For example, the silicon-containing coating liquid may comprise at least one crosslinkable and / or vulcanizable silicon-containing polymer or polymer precursor, which may be selected, in particular, from the group consisting of crosslinkable polysiloxanes, crosslinkable polysiloxane copolymers, crosslinkable polysilanes, crosslinkable polysilane copolymers, their precursors, and combinations thereof.

In particular, the silicon-containing coating liquid may comprise one or more first components selected from the group consisting of linear and / or branched polysiloxanes, polysilanes, (co) polymers and their precursors and one or more second, especially multifunctional crosslinking, components Components at one or more ends and / or on the polymer chains (in total) have at least two functional group, and wherein the functional groups of the second components can react with the functional groups of the first components. For example, the second component (s) may be multifunctional crosslinking silicon-containing compounds, such as multifunctional crosslinking silanes. The formation of the highly hydrophobic layer may be based on a condensation reaction or an addition reaction of the first and second components.

The functional groups of the first and second component (s) may be selected, for example, depending on one another, from the group consisting of silanol groups, acetoxy groups, alkoxy groups, oxime groups, vinyl groups, hydride groups, Epoxy groups, thiol groups and amino groups.

In the case of a condensation reaction, the functional groups of the first component (s) may be, for example, silanol groups (Si-OH). For example, the first component may be silanol-terminated, linear or branched polydimethylsiloxane. The functional groups of the second component (s) can be selected, for example, from the group consisting of acetoxy groups, alkoxy groups and oxime groups. Conversely, it is also possible that the functional groups of the first component (s) are acetoxy, alkoxy and / or oxime groups and the functional groups of the second component (s) are silanol groups. The silanol group can advantageously condense with many multifunctional crosslinking components, in particular silanes which have, for example, acetoxy, alkoxy and / or oxime groups as functional groups. In this case, catalysts such as tin salts and / or titanates can be used to accelerate the reaction. Silanol groups can also react with polymethylhydrosiloxane copolymers.

An addition reaction, for example a silylation reaction, in particular a hydrosilylation reaction, can be based, for example, on the reaction of a hydride group, in particular Si-H, with a vinyl group. The reaction can be catalyzed in particular by platinum group metal complexes. For example, a vinyl-functionalized, in particular vinyl-terminated, polydimethylsiloxane can be crosslinked with a hydride-containing precursor (precursor), for example with a plurality of hydride groups, such as polymethylhydrosiloxane.

It is likewise possible for the coating liquid to comprise at least one, in particular reactively functionalized, for example epoxy-functionalized, silicone derivative. Thus, advantageously, a chemical bonding of the highly hydrophobic layer to be formed to the material of the wiper rubber base body can be achieved.

Furthermore, it is possible that the coating liquid comprises at least one, in particular functionalized, fluorinated compound for forming the highly hydrophobic layer.

For example, the coating liquid may comprise at least one compound selected from the group consisting of silicone oils, vinyl-functionalized polysiloxanes, epoxy-functionalized polysiloxanes, thiol-functionalized polysiloxanes, amino-functionalized polysiloxanes, alkoxysilanes, in particular organoalkoxysilanes and / or fluorine-functionalized organoalkoxysilanes, for example their organic ones Group comprises, in particular reactive, epoxy group, and combinations thereof. For example, the coating liquid may comprise at least one compound selected from the group consisting of silicone oils, vinyl-functionalized polydimethylsiloxanes, epoxy-functionalized polydimethylsiloxanes, thiol-functionalized polydimethylsiloxanes, amino- functionalized polydimethylsiloxanes, alkoxysilanes, in particular organoalkoxysilanes and / or fluorine-functionalized organoalkoxysilanes, for example, the organic group of which comprises an especially reactive epoxy group, and combinations thereof.

Furthermore, the coating liquid may in particular comprise at least one solvent, for example from the group of hydrocarbons, for example alkanes and aromatics, for example heptane, naptha and / or xylene.

In addition, the method may further comprise the step of: c) heating the coated and structured wiper gum base to a temperature ≥ 100 ° C., in particular ≥ 120 ° C., for example between ≥ 100 ° C. and ≦ 200 ° C., for example between ≥ 120 ° C. and ≤ 160 ° C, include

As part of a special embodiment, a wiper rubber base in the form of a double (wiper rubber) profile is provided in step a). In this case, the method can furthermore, in particular after process step b) and / or c), comprise process step d) separating, in particular cutting, of the coated and structured double (wiper rubber) profile in two wiper rubbers.

The surface structuring can be formed for example by a powder spray or powder coating process or by a wet coating or wet coating process, for example a suspension coating process, or by vortex sintering or by a film coating process or lamination process. Suitable methods for forming the surface structuring are, for example, in the document WO 2008/113624 A1 described.

With regard to further features and advantages of the method according to the invention, reference is hereby explicitly made to the explanations in connection with the wiper blade according to the invention, the later explained wiper blade and to the figures and the description of the figures.

Another object of the present invention is a wiper blade, which comprises a wiper rubber according to the invention or produced according to the invention or is equipped therewith.

With regard to further features and advantages of the wiper blade according to the invention, reference is hereby explicitly made to the explanations in connection with the wiper rubber according to the invention, the method according to the invention and to the figures and the description of the figures.

Drawings and examples

Further advantages and advantageous embodiments of the subject invention are illustrated by the drawings and explained in the following description. It should be noted that the drawings have only descriptive character and are not intended to limit the invention in any way. Show it

1 a schematic cross-sectional view of an embodiment of a wiper blade according to the invention;

2 a schematic cross-sectional view of an embodiment of a wiper blade according to the invention during operation; and

3 a scanning electron micrograph of an embodiment of a wiper blade according to the invention.

1 shows a greatly enlarged and schematic cross-sectional detail of an embodiment of a wiper blade according to the invention 10 , 1 illustrates that the squeegee 10 a squeegee basic body 1 includes. In the in 1 shown portion of the wiper rubber body 1 the surface has a surface structure with elevations 2 in the micrometer range. The surveys 2 become thereby by particles 2 formed, which on the surface of the wiper rubber base 1 firmly adhere or are associated with it. The elevations or particles 2 are spaced from each other, not connected to each other, and randomly distributed on the surface. The particles 2 thus form a layer or open or non-continuous layer. The particle 2 are doing so with the wiper base 1 that its surface has particle-uncovered areas randomly distributed between the peaks / particles 2 are formed.

1 further illustrates that the particle-uncovered or particle-free regions of the surface of the wiper rubber base body 1 So the areas between the surveys or particles 2 with a highly hydrophobic layer 3 are covered, which has a small layer thickness, for example in the nanometer range. Through the highly hydrophobic layer 3 For example, the particle-uncovered areas or the areas between the elevations or particles 2 be provided with highly hydrophobic or strongly water-repellent properties. In this case, the surface of the highly hydrophobic layer may have a contact angle with respect to water of ≥ 120 °. The highly hydrophobic layer 2 is essentially at most through the surveys or particles enclosed with it 2 interrupted and can be considered as a substantially continuous layer. The highly hydrophobic layer 3 For example, by a post-treatment of the particles uncovered surface areas or the areas between the elevations or particles 2 be formed.

1 illustrates that the elevations / particles 2 For example, in that the elevations have a height in the micrometer range and the highly hydrophobic layer 2 has a layer thickness in the nanometer range, between the elevations 2 formed, highly hydrophobic layer 3 overtop.

As a result, a surface topography can be realized, in which the particles 3 serve as spacers and thereby both the friction of the wiper blade rubber 10 reduce on the disc to be wiped, as well as a lotus effect and thus ensure water-repellent properties, which have an advantageous effect on the wiping quality and the Umlegleistung.

The squeegee basic body 1 For example, from ethylene-propylene-diene monomer rubber (EPDM), the elevations or particles 2 made of ultra-high molecular weight polyethylene (UHMW-PE) and the highly hydrophobic layer 3 silicone oil or crosslinked silicone compositions, for example of a silicone oil, polysiloxane or polysilane.

2 shows a cross-sectional view through an embodiment of a wiper blade according to the invention 10 during operation. It shows 2 a cross section through a wiper rubber base 1 . 1a . 1b . 1c , 2 illustrates that the squeegee base 1 . 1a . 1b . 1c a wiper lip section 1a and a fixing portion 1b includes. Between the wiper lip section 1a and the attachment portion 1b is a Kippstegabschnitt 1c formed, which is a tilting of the wiper lip portion 1a with respect to the attachment section 1b allows. 2 shows that the wiper lip section 1a two wiping edges 1a ' , one between the wiping edges 1a ' trained face 1a ' and two, each at a wiping edge 1a ' adjacent side surfaces 1 a ''' having, wherein the surfaces of the side surfaces 1 a ''' at least in the at the wiping edges 1a ' adjacent areas with surface structuring surveys 3 and a highly hydrophobic layer formed therebetween 2 are provided. The face 1a ' is unstructured and uncoated. Such a configuration, for example, by the production described in Example 3 of a so-called double (wiper rubber) profile, a profile whose shape corresponds to the shape of two connected to the later end faces squeegee can be achieved. Surprisingly, it has been found that a coating on the wiping edges 1a ' adjacent areas of the side surfaces 1 a ''' the wiper lip 1a sufficient to achieve very good wiping properties.

2 further illustrates the wiping behavior of the wiper blade rubber 10 , 2 illustrates that the more hydrophobic the wiper lip section 1a , in particular its side surface 1 a ''' , is, the more water 20 is from the contact line between wiper lip section 1a and disc 30 pressed away, leaving less or even no water 20 between the wiper lip section 1a , in particular the wiping edge 1a ' , and the disc 30 can pass through and a formation of a water film between the wiper lip edge 1a ' and the disc 30 can be prevented. This is similar to wiping on a dry disk where it has also been observed that the static friction at the transfer point is large enough to cause the wiper lip to flip over. Overall, not only the wiping quality but also the Umlegleistung the wiper blade can be improved so advantageously.

Further illustrated 2 the angle ⊝ of the bend, which during the wiping operation between the attachment portion 1c and the wiper arm occurs. As a rule, the wiper lip is not turned over when the bending angle ⊝ is zero or greater than a specific limit value. The size of the angle range between zero and the reaching of the limit value at which no turning over of the wiper lip more takes place, it can be used as a measure of the Umlegleistung the wiper lip or the wiper blade rubber.

3 shows a scanning electron micrograph of an embodiment of a wiper blade according to the invention with a wiper rubber base 1 , which was made of a double (wiper) profile. The elevations in the form of particles 2 as well as the highly hydrophobic layer formed therebetween 3 are clearly visible. In addition shows 3 in that the cutting edge at which the double (wiper rubber) profile has been divided into two individual wiper rubber profiles and which represents the end face of the wiper lip section of the wiper rubber is unstructured and uncoated and neither particles 2 another highly hydrophobic layer 3 having.

example 1

A vulcanized wiper rubber profile of ethylene-propylene-diene monomer (EPDM) was provided and its wiper lip provided with substantially spaced, adherent particles having an average particle size of about 10 μm from ultra-high molecular weight polyethylene (UHMW-PE). The UHMW-PE particles were substantially spaced apart and in particular not connected to one another and formed a particle layer or open or non-continuous layer. Between the particles there remained an open or particle-covered surface area recessed with respect to the particles.

Thereafter, a 1% solution of silicone oil (Dow Corning DC200) was sprayed in heptane. Due to the carrier solvent heptane, the squeegee rubber swelled, which favored penetration of silicone oil into the EPDM surface layer. After evaporation of the heptane, a thin silicone film remained on the previously exposed, particle-covered, particle-recessed surface area. The UHMW-PE particles had a particle size in the micrometer range. By contrast, the silicone film formed had a layer thickness in the nanometer range, which is why the UHMW-PE particles projected above the silicone film. Due to the spraying process, the UHMW-PE particles were also wetted with silicone, which advantageously did not interfere during operation. A low wetting of the particles, possibly even no wetting of the particles, can be achieved inter alia by a suitable adjustment of the sprayed solution or suspension.

The surface of the wiper blade provided with the silicone film exhibited significantly better water-repellent properties than a comparative wiper blade made of EPDM with only UHMW-PE particles.

In order to investigate the behavior of the wiper blade provided with the silicone film and the comparison wiper blade rubber under contact force, rubbing tests were carried out in which the wiper blade was wetted with water and rubbed over the water-wetted surfaces. In the comparative wiper blade, the water-repellent properties initially based on the lotus effect disappeared after some time and a film of water forms. The wiping rubber lip coated with the silicone film advantageously retained the good water-repellent properties.

In addition, the reposting was done by means of 2 explained bending angle range during a wiping operation on a wet disc examined. The wiper lip provided with the silicone film advantageously has a larger bending angle range ⊝ and thus a better repositioning performance than the comparison wiper rubber lip.

Example 2:

As in Example 1, a vulcanized wiper rubber profile of ethylene-propylene-diene monomer (EPDM) was provided, the surface of which was provided with substantially spaced, ultra-high molecular weight polyethylene (UHMW-PE) adherent particles.

Thereafter, a silicone coating solution of the following composition was sprayed. component Type weight proportion PS 255 base polymer 25,00 PS 445 base polymer 45,00 naphtha solvent 660.00 PS 120 crosslinkers 1.90 platinum complex catalyst 0.28 PS 255 poly (dimethylsiloxane) - (0.1-0.3) (methylvinylsiloxane) copolymer from United Chemical Technologies, Bristol, PA, USA;
PS 455 Vinyl-terminated low molecular weight dimethylpolysiloxane from United Chemical Technologies, Bristol, PA, USA;
PS 120 Hydride-functionalized, low molecular weight methylhydrogenpolysiloxane from United Chemical Technologies, Bristol, PA, USA;
Platinum complex divinyltetramethyldisiloxane platinum complex in xylene

After evaporating the carrier solvent to form a dry coating having a layer thickness of about 2 μm, the squeegee rubber profile was vulcanized at 130 ° C for 5 minutes. The UHMW-PE particles towered over the formed silicone film with an average particle size of 10 μm.

The surface of the wiper blade provided with the silicone film exhibited significantly better water-repellent properties than a comparative wiper blade made of EPDM with only UHMW-PE particles.

Frictional tests in which the squeegee was wetted with water and rubbed over the water-wetted surfaces showed that the water-repellent properties initially based on the lotus effect disappeared with the comparative squeegee after some time and a film of water formed. The wiping rubber lip coated with the silicone film advantageously retained the good water-repellent properties.

In addition, the reposting was done by means of 2 explained bending angle range during a wiping operation on a wet disc examined. The wiper lip provided with the silicone film advantageously has a larger bending angle range ⊝ and thus a better repositioning performance than the comparison wiper rubber lip.

Example 3

Vulcanized double wiper rubber profile of ethylene-propylene-diene monomer (EPDM) was provided. A double (wiper rubber) profile can in this case be understood in particular as meaning a profile whose shape corresponds to the profile of two wiper rubber profiles which are connected to one another in the region of the wiper lips. In the case of the double (wiper rubber) profile, the regions provided for the formation of the wiper lips were provided, analogously to Examples 1 and 2, with substantially spaced, firmly adhering particles having an average particle size of approximately 10 μm from ultrahigh molecular weight polyethylene (UHMW-PE).

Thereafter, the silicone coating solution of Example 2 was sprayed on.

After the double profile was cured at 150 ° C for 5 minutes, the double (squeegee) profile was cut longitudinally and separated into two separate squeegee profiles.

An investigation of the cutting edge by scanning electron microscopy (see 3 ) revealed that cutting did not damage the coating on the cut edge and in particular did not flake off.

The surfaces of the squeegee rubber lips provided with the silicone film had significantly better water-repellent properties than comparison rubber wiper rubber lips made of EPDM with only UHMW-PE particles.

Frictional tests in which the squeegee was wetted with water and rubbed over the water-wetted surfaces showed that the water-repellent properties initially based on the lotus effect disappeared after some time and a film of water appeared in the comparative wiper rubbers formed. The wiping rubber lips coated with the silicone film advantageously retained the good water-repellent properties.

In addition, the reposting was done by means of 2 explained bending angle range during a wiping operation on a wet disc examined. The wiper lips provided with the silicone film advantageously had a larger bending angle range Θ and thus a better transfer performance than the comparison wiper rubber lips.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of 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.

Cited patent literature

• WO 2008/113624 A1 [0004, 0062]
• US 6982112 [0005]

Claims (15)

Squeegee ( 10 ) for a wiper blade, in particular for a windscreen wiper, comprising a wiper rubber base body ( 1 . 1a . 1b . 1c ), wherein the surface of the wiper rubber base body ( 1 . 1a . 1b . 1c ) in at least a portion of the wiper gum base ( 1 . 1a . 1b . 1c ) a surface structuring with elevations ( 2 ) in the micrometer range, with between the surveys ( 2 ) a highly hydrophobic layer ( 3 ), and the surveys ( 2 ) the highly hydrophobic layer ( 3 ), which between the surveys ( 2 ) is formed, project beyond. A squeegee according to claim 1, wherein the highly hydrophobic layer ( 3 ) is essentially consistent. A squeegee according to claim 1 or 2, wherein the highly hydrophobic layer ( 3 ) comprises at least one silicon-containing compound, in particular at least one silicon-containing polymer. A squeegee according to any one of claims 1 to 3, wherein the highly hydrophobic layer ( 3 ) comprises at least one silicon-containing compound selected from the group consisting of silicone oils, polysiloxanes, polysiloxane copolymers, polysilanes, polysilane copolymers, and combinations thereof. A squeegee according to any one of claims 1 to 4, wherein the highly hydrophobic layer ( 3 ) is prepared from at least one compound selected from the group consisting of silicone oils, vinyl-functionalized polysiloxanes, epoxy-functionalized polysiloxanes, thiol-functionalized polysiloxanes, amino-functionalized polysiloxanes, alkoxysilanes, in particular organoalkoxysilanes and / or fluorine-functionalized organoalkoxysilanes, and combinations from that. A squeegee according to any one of claims 1 to 5, wherein the bumps ( 2 ) are formed substantially spaced from each other. A squeegee according to any one of claims 1 to 6, wherein the bumps ( 2 ) are formed randomly distributed. A squeegee according to any one of claims 1 to 7, wherein the bumps ( 2 ) by particles attached to the wiper rubber base surface ( 2 ) are formed. A squeegee according to claim 8, wherein the particles ( 2 ) comprise at least one material selected from the group consisting of ultra-high molecular weight polyethylene, high density polyethylene, low density polyethylene, isotactic polypropylene, polyamide, polytetrafluoroethylene, carbon black, inorganic fillers, especially silicates, metal oxides and / or metals or metal alloys, and mixtures from that. A squeegee according to any one of claims 1 to 9, wherein the squeegee base ( 1 . 1a . 1b . 1c ) - a wiper lip section ( 1a ) and - a fixing section ( 1b ), wherein the surface of the wiper lip portion ( 1a ) at least partially with the surveys ( 2 ) and the highly hydrophobic layer formed therebetween ( 3 ) is provided. Wiper rubber according to one of claims 1 to 10, wherein the wiper lip section ( 1a ) - two wiping edges ( 1a ' ), - one between the wiping edges ( 1a ' ) formed end face ( 1a ' ) and - two, each at a wiping edge ( 1a ' ) adjacent side surfaces ( 1 a ''' ), wherein the surfaces of the side surfaces ( 1 a ''' ) at least in the at the wiping edges ( 1a ' ) adjacent areas with the surface-structuring surveys ( 3 ) and the highly hydrophobic layer formed therebetween ( 2 ), in particular wherein the end face ( 1a ' ) is unstructured and uncoated. A squeegee according to any one of claims 1 to 11, wherein the squeegee base ( 1 . 1a . 1b . 1c ) comprises an elastomer material, in particular which is selected from the group consisting of ethylene Propylene-diene monomer rubber, ethylene-propylene monomer rubber, chlorobutyl rubber, bromobutyl rubber, chloroprene rubber, natural rubber, polyurethane rubber and combinations thereof. Process for producing a wiper blade rubber, in particular according to one of Claims 1 to 12, comprising the process steps: a) Provision of a wiper rubber base body ( 1 ) whose surface in at least a portion of the wiper rubber base body has a surface structure with elevations ( 2 ) in the micrometer range. b) coating the surface-structured portion of the wiper rubber base body with a highly hydrophobic layer ( 3 ), in particular in such a way that the surveys ( 2 ) between the surveys ( 2 ) forming, highly hydrophobic layer ( 3 ). A method according to claim 13, wherein in step b) a silicon-containing coating liquid is applied, in particular sprayed, to the section provided with the surface structuring, in particular, wherein the silicon-containing coating liquid comprises at least one silicon-containing compound or compound precursor selected from the group consisting of silicone oils, polysiloxanes, polysiloxane copolymers, polysilanes, polysilane copolymers, their precursors and combinations thereof, in particular wherein the silicon-containing coating liquid comprises at least one solvent, in particular from the group of hydrocarbons, for example the alkanes and aromatics. Wiper blade comprising a squeegee according to one of claims 1 to 12 or produced by a method according to claim 13 or 14.

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