DE102007036780A1 - Process for producing a coated elastomer profile, an elastomer profile and its use - Google Patents

Abstract

The invention relates to a method for producing a coated elastomer profile (1) having a base substrate (3) made of an elastomeric material, wherein in a first step a coating material (11) is applied to the base substrate (3) of the elastomeric material, wherein the coating material ( 11) contains a polymer material-containing lubricant (13). In a second step, the base substrate (3) provided with the coating material (11) is heated to a temperature above the melting temperature of the polymer material contained in the lubricant (13), forming a polymer film (17) on the surface of the elastomer profile , Finally, the elastomeric profile is irradiated to cure the polymer film (17). The invention further relates to an elastomer profile comprising a base substrate (3) made of an elastomer material, a coating (5) comprising a coating material (11) containing a lubricant (13) containing at least one polymer material. The coating (5) comprises a first layer (15) formed from the coating which contains substantially crosslinked polymeric material. The elastomer profile finds use, e.g. as a squeegee for windscreen wipers or disc pullers.

Description

State of the art

The The invention relates to a process for producing a coated Elastomerprofiles with a base substrate made of an elastomeric material. Farther the invention is based on an elastomer profile according to the The preamble of claim 10. The invention finally relates also the use of an elastomer profile according to the invention or a produced by the process according to the invention Elastomer Profiles.

elastomer profiles be z. B. used for the production of wiper blades or sealing cords. such Wiping gums are z. B. on windscreen wipers of motor vehicles used. Other applications of wiper blades are z. B. disc puller, as they are z. B. used for cleaning glass sheets in households become.

In order to Windscreen wiper with little effort to a satisfactory Result, it is generally required that Friction during operation of a wiper blade used as a windshield wiper to reduce. For this purpose, it is known to the squeegee z. B. with a Graphite coating or lubricating coating to provide.

Coatings used to reduce friction often include thermoset two-component systems of binder and hardener. Such thermosetting systems include, for. As hydroxyl-functionalized polyester, acrylic polymers or urethane polymers and, for example, melamine, aldehyde or isocyanate hardener. In order to reduce the friction of the coating surface, graphite or molybdenum disulfide is generally added as a solid lubricant. This is z. B. off US Pat. No. 6,696,391 known.

Alternatively, it is from the prior art z. B. off US-B 7,028,367 it is known to admix the elastomeric material for the squeegee with an additive for reducing the friction. Suitable additives include PTFE, graphite, boron nitride, fluoropolymers or fluorine-containing additives.

disadvantage of graphite as a solid lubricant in a coating is included, that the graphite particles the bond strength and thus reduce the wear resistance of the coating. In many cases, the proportion of graphite exceeds the critical pigment volume concentration of the coating, what to a low adhesion and thus an insufficient wear resistance the coating leads. The high proportion of graphite is necessary to the low frictional properties of the coating surface to achieve.

polyethylene, Polypropylene or polytetrafluoroethylene powder used for reduction the friction resistance of the coating are used, migrate to the surface of the coating, reducing its lubricating effect is achieved. Disadvantage, however, is that the powder is easily removed from the Coating surface can be cut out due to a lack of liability.

Farther are also low melting point waxes as a lubricant used. These migrate during thermal curing the coating to the surface of the coating. At the Cooling the coating forms a thin wax-enriched surface on the coating out. As a result, the friction of the wiper blade is reduced. disadvantage However, the low melting point waxes in particular in a hot environment, for example when exposed to the sun are, soften, resulting in both the frictional resistance as well deteriorate the abrasion resistance. Especially The waxes with low melting point can in this If the windshield wiper operates, stick to the windshield stay. On the other hand, waxes with a high melting point the advantage that they are not soft even when exposed to sunlight become. Disadvantage, however, is that waxes with high melting point no continuous film on the coating surface form.

Disclosure of the invention

• (a) Auftragen eines Beschichtungsmaterials auf das Grundsubstrat aus dem Elastomermaterial, wobei das Beschichtungsmaterial ein Polymermaterial enthaltendes Schmiermittel enthält,
• (b) Erwärmen des mit dem Beschichtungsmaterial versehen Grundsubstrats auf eine Temperatur oberhalb der Schmelztemperatur des Polymermaterials, das im Schmiermittel enthalten ist, wobei sich ein Polymerfilm auf der Oberfläche des Elastomerprofiles ausbildet,
• (c) Bestrahlen des Elastomerprofiles, um dem Polymerfilm zu härten.

An inventive method for producing a coated elastomer profile with a base substrate made of an elastomeric material comprises the following steps:

• (a) applying a coating material to the base substrate of the elastomeric material, wherein the coating material contains a lubricant containing polymer material,
• (b) heating the base substrate provided with the coating material to a temperature above the melting temperature of the polymer material contained in the lubricant, whereby a polymer film is formed on the surface of the elastomer profile,
• (c) Irradiating the elastomeric profile to cure the polymer film.

By the coating of the base substrate with the coating material, which contains a lubricant, good friction properties of the Elastomerprofiles achieved. By curing the polymer film the resistance of the coating to abrasion is increased.

The elastomer profile can z. As an extruded, an injection molded or a compression molded Be profile.

In an embodiment, the lubricant contained in the acts Polymer material as lubricant. Usually that is Polymer material contained in a binder. As a binder are suitable for. As polyacrylates, polyurethanes, polyester-polyurethanes, Polyether polyurethanes, polyesters, polyamides, polyamide-imides.

In A second embodiment contains the lubricant a solid lubricant that is in the form of particles that are at least partially coated with the polymer material.

By heating the material provided with the coating material Base substrate to a temperature above the melting temperature of the polymer material in step (b) migrates the polymer material to the surface of the coating and melts there. hereby forms on the surface of the coating material a film of the polymer material. By hardening of the polymer film in step (c) thus results in a solid surface, the better Abriebeigenschaften with also improved friction properties having. If the lubricant contains a solid lubricant, so does this through the cured polymer film in the coating held. It avoids this by abrasion from the coating is dissolved out.

In an embodiment of the invention is the polymer material, which is contained in the coating material, a wax with a low melting point. Waxes with a low melting point have the property that these during curing Be the coating material at elevated temperature to do so tend to diffuse to the surface of the coating. However, due to waxes with a low melting point, the coefficient of friction is not sufficiently reduced and also the abrasion resistance is low, it is necessary to treat the surface, to achieve the desired properties. This will be done achieved that deposited on the surface Wax with a low melting point hardened by irradiation becomes. This forms a wax with a high melting point, which better friction properties and also better abrasion properties having.

suitable Waxes contained in the coating material are e.g. B. Paraffin wax, carnauba wax, microcrystalline wax or Fischer-Tropsch wax.

In an alternative embodiment is the polymeric material selected from polyethylene (LDPE, LLDPE, HDPE), polypropylene, Polyetrafluoroethylene, polyamides and PTFE-modified polyethylene.

These mentioned polymers also have the property during curing of the coating material forms a film on the surface to build. In addition, they can crosslink by irradiation and harden in this way. So z. B. known that by Irradiation of Low Density Polyethylene (LDPE) by Electron Beam Hardening a cross-linking occurs by which the abrasion resistance and the sliding properties as well as the thermal properties, z. As the melting range can be improved. The curing is achieved by a reaction route known in the art is and on the formation of double bonds in the polyolefin chains based on radiation. Also, the crosslinking rate z. B. by addition be increased by additives. As an additive is suitable for Example triallyl isocyanurate (TAIC).

In a preferred embodiment of the invention is as Polymer material used a wax with a low melting point, which by electron beam curing in an analogous manner as the LDPE can be cured. By networking the Wax layer on the surface by electron beam curing the melting point is increased, resulting in an improved hardness, improved sliding properties, improved abrasion resistance and an increased wax transition temperature results. Such waxes are, for example, paraffin wax or microcrystalline Wax.

If the coating material contains a solid lubricant, so this is preferably selected from graphite, polytetrafluoroethylene, molybdenum disulfide or mixtures thereof. Other suitable solid lubricants are z. As well as talc, polyamide powder or polyethylene powder.

When Elastomer material for the elastomer profile are all suitable Elastomer materials suitable for the application of the elastomer profile have required properties. The elastomeric material is preferred for the elastomer profile selected from natural rubber (NR), chloroprene rubber (CR), ethylene-propylene terpolymer (EPDM), Ethylene-propylene rubber (EPM), polyurethane, butyl rubber, nitrile rubber, Silicone rubber and thermoplastic elastomer (TPE) and blends it.

In addition to the above-described irradiation of the elastomer profile with electron beams to cure the polymer film, it is also possible that the irradiation is by gamma radiation. The advantage of gamma radiation over electron radiation is that the gamma radiation continues to penetrate the coating. As a result, also contained in the coating polymer is hardened material.

The The invention further relates to an elastomeric profile having a base substrate made of an elastomer material, a coating of a coating material comprising a lubricant containing at least one polymer material contains. According to the invention, the coating a first layer of the coating material on which a second layer is formed, the substantially crosslinked polymer material contains.

advantage compared to the coatings known from the prior art it is that the second layer, which is essentially cross-linked Polymer material contains improved friction properties and has improved abrasion properties. This will increase the stability the elastomer profile z. B. is used as a squeegee, elevated.

In a first embodiment forms the polymer material, which is crosslinked at the surface of the coating, the lubricant. Alternatively, it is also possible that the lubricant contains a solid lubricant. This is generally located at least partially on the surface the coating, whereby the friction is reduced.

The produced by the process according to the invention Elastomer profile or the elastomer profile according to the invention be z. B. as a squeegee for windscreen wipers of motor vehicles or for disc pullers, as z. B. for cleaning glass sheets used in households, used. Further areas of application of elastomer profiles produced according to the invention are z. As door seals, windshield seals, window seals in vehicles, elastomer sealing inserts, O-rings, elastomer sealing profiles, Elastomer guide profiles.

Brief description of the drawings

embodiments The invention is illustrated in the drawings and in the following Description explained in more detail.

It demonstrate:

1 a cross section through an elastomer profile with coating,

2 a schematic representation of the process for the preparation of the coated elastomer profile.

embodiments the invention

In the 1 an elastomer profile formed according to the invention is shown with coating.

An inventively designed, coated elastomer profile 1 includes a base substrate 3 , The basic substrate 3 is generally a profile made by an extrusion process, an injection molding process or a compression molding process. Usually this is the basic substrate 3 made of an elastomeric material. As elastomeric material for the base substrate 3 are suitable as described above z. B. NR, CR, EPTM, EPM or mixtures thereof. If the basic substrate 3 are used for wiper blades of windscreen wipers, it is desired that the coefficient of friction between the used as a squeegee, coated elastomer profile 1 and a disk on which the windshield wiper is used is reduced. The lower coefficient of friction leads z. B. to a reduced running noise. The lower coefficient of friction is achieved according to the invention by applying a coating 5 on the basic substrate 3 , According to the invention, the coating contains 5 a polymeric material which aids in curing the coating 5 a polymer film on the surface of the coating 5 formed. In order to achieve the desired frictional properties and abrasion properties, the polymer film is formed by irradiating the elastomer profile 1 hardened.

The in 1 illustrated cross-section of a coated elastomer profile 1 shows two squeegees, first as an elastomeric profile 1 getting produced. To produce individual windshield wipers, it is necessary that the elastomer profile 1 along its midline 7 is disconnected. There are two individual wiper rubbers made of an elastomer profile 1 produced. As an alternative to the coating of the elastomer profile, which comprises the two wiper rubbers, it is also possible to use the elastomer profile 1 first at the midline 7 to separate and then to coat.

In 2 schematically a method for producing an inventively designed elastomer profile is shown.

In a first step, coating material 11 on the basic substrate 3 applied. The coating material 11 contains a lubricant 13 containing a polymeric material. The lubricant 13 is preferably dispersed in a binder. This is the lubricant 13 preferably in the form of small particles dispersed in the binder.

Any binder known to those skilled in the art which is used for coatings is suitable as a binder for the coating material. However, it should be ensured that the binder on the elastomeric material of base substrate 3 adheres to the coating 5 not from the basic substrate 3 can replace. The adhesion can also be improved by adding an adhesion promoter in the coating material. Alternatively, it is also possible to first apply a primer to the base substrate 3 applied. Suitable adhesion promoters are z. B. chlorinated polymers in organic solvents.

When Binders are, in particular, polyacrylate resins, polyurethane resins, Polyester-polyurethane resins, polyether-polyurethane resins, polyester resins, Polyamide resins, polyamideimide resins. These resins can be crosslinked be, z. With methylated iminomelamine aminoplast crosslinkers, Isocyanate crosslinkers or epoxy crosslinkers.

The polymer material used in the lubricant 13 is included is z. As a wax or a polyolefin. Also suitable are polytetrafluoroethylene or crosslinkable polyamides. In particular, polytetrafluoroethylene and the crosslinkable polyamides can be used simultaneously as a lubricant of the lubricant. In one embodiment, the lubricant contains 13 but a solid lubricant. As a solid lubricant z. As graphite or molybdenum disulfide used.

After application of the coating material 11 on the elastomeric material of the base substrate 3 becomes the coating material 11 hardened. The curing takes place in general by heat. By heating the coating material 11 rise in the coating material 11 dispersed particles of the lubricant 13 to the surface of the coating material 11 on. This forms a first layer 15 out on the base substrate 3 rests and essentially the binder of the coating material 11 contains. On the first layer 15 a second layer forms 17 which is essentially the lubricant 13 contains. In this way arises on the basic substrate 3 a surface with a low coefficient of friction.

From the second layer 17 , which is due to the migration of the particles of the lubricant 13 formed on the surface of the coating, the lubricant particles contained, for. As graphite particles, molybdenum disulfide, after curing of the binder during operation of the windscreen wiper still be dissolved, since the adhesion between the polymer material, which forms the second layer and the lubricant particles is not sufficiently large. It is also possible that the second layer 17 is abraded by the movement of the windshield wiper on the windshield. This is particularly the case when the polymer material used is soft, as z. B. in soft wax layers is the case. In particular, a characteristic of soft wax layers is that they have a low softening point, thereby facilitating abrasive removal and transfer of the wax to the windshield.

To the second layer 17 to stabilize and the lubricant in the second layer 17 The coating will hold 17 therefore irradiated according to the invention to the second layer 17 cure. The irradiation of the second layer 17 takes place for. B. by electron beam or gamma radiation. This is the coating 5 an irradiation device 19 exposed, from the one irradiation 21 on the coating 5 emanates. For irradiation, both electron beams and gamma rays are suitable.

When using electron beams for irradiation of the coating 5 form on the surface of the second layer 17 bonds between the polymer molecules contained therein, thereby crosslinking the polymer molecules. That in the second layer 17 contained polymer material is cured and it forms a cured layer 23 , By curing the second layer 17 becomes the surface of the coated elastomer profile 1 stabilized. The polymer material can no longer be removed so easily abrasive. In addition, particles of the lubricant in the cured layer 23 kept better. These can not be easily removed. In this way, the lubricating effect of the coated elastomer profile 1 improved and the coefficient of friction permanently reduced.

Unlike electron beams, gamma rays penetrate deeper into the second layer 17 one. The hardened layer 23 takes up a greater thickness than during curing by irradiation 21 with electron beams.

As the curing of the second layer 17 to the hardened layer 23 Is done with electron beams or gamma radiation, are suitable as polymer material in the lubricant 13 is included and the second layer 17 forms, all polymer materials that can be cured by irradiation with electron beams or gamma rays. Suitable polymers are in particular polyolefins, for example polypropylene (PP), polyethylene (HDPE, LDPE, LLDPE) and other polymeric materials, for. As polytetrafluoroethylene (PTFE) and crosslinkable polyamides. Since, in particular, the latter can also act as a lubricant at the same time, it is not necessary when using polytetrafluoroethylene or crosslinkable polyamides to additionally use a solid lubricant, such as graphite or molybdenum disulfide.

As a result of the surface coating, the coefficient of friction of the elastomer profile 1 This can be used wherever the elastomer profile 1 is passed over another surface, as z. B. in windshield wipers on motor vehicles or disc pullers, such as these z. B. be used in households, the case.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 6696391 B [0004]
• US 7028367 B [0005]

Claims (14)

Process for producing a coated elastomer profile ( 1 ) with a base substrate ( 3 ) of an elastomeric material, comprising the following steps: (a) applying a coating material ( 1 ) on the basic substrate ( 3 ) of the elastomeric material, wherein the coating material ( 11 ) a lubricant containing polymer material ( 13 ), (b) heating the with the coating material ( 11 ) provided basic substrate ( 3 ) to a temperature above the melting temperature of the polymer material contained in the lubricant ( 13 ), wherein a polymer film ( 17 ) is formed on the surface of the elastomer profile, (c) irradiating the elastomer profile to the polymer film ( 17 ) to harden. Process according to claim 1, characterized in that the lubricant ( 13 ) polymer material acts as a lubricant. Method according to claim 1, characterized in that the lubricant ( 13 ) contains a solid lubricant which is in the form of particles which are at least partially coated with the polymeric material. Method according to one of the claims 1 to 3, characterized in that the polymer material is a wax with a low melting point. A method according to claim 4, characterized in that the wax is paraffin wax or a microcrystalline one Wax is. Method according to one of the claims 1 to 3, characterized in that the polymer material is selected is polyethylene, in particular LDPE, LLDPE, HDPE, polypropylene, Polytetrafluoroethylene, polyamides, or PTFE-modified polyethylene. Method according to one of the claims 3 to 6, characterized in that the solid lubricant is selected is made of graphite, polytetrafluoroethylene, molybdenum disulfide, Talc, polyamide powder, polyethylene powder or mixtures thereof. Method according to one of claims 1 to 7, characterized in that the elastomer material for the base substrate ( 3 ) is selected from natural rubber, chloroprene rubber, ethylene-propylene terpolymer, ethylene-propylene rubber, polyurethane, butyl rubber, nitrile rubber, silicone rubber, thermoplastic elastomers and mixtures thereof. Method according to one of the claims 1 to 8, characterized in that the irradiation in step (c) with electron beams or gamma radiation. Elastomer profile with a base substrate of an elastomeric material, a coating ( 5 ) from a coating material ( 11 comprising a lubricant containing at least one polymer material ( 13 ), characterized in that the coating ( 5 ) a first layer ( 15 ) from the coating material ( 11 ), on which a second layer ( 17 ), which contains substantially crosslinked polymer material. Elastomer profile according to claim 10, characterized in that the lubricant ( 13 ) further contains a solid lubricant, which is preferably selected from graphite, polytetrafluoroethylene, molybdenum disulfide, talc, polyamide powder, polyethylene powder or mixtures thereof. Elastomer profile according to claim 10 or 11, characterized in that the polymer material is selected is polyethylene, in particular LDPE, LLDPE, HDPE, polypropylene, Polytetrafluoroethylene, polyamides, PTFE-modified polyethylene, or a wax with a low melting point. Elastomer profile according to one of claims 10 to 12, characterized in that the elastomer material of the base substrate ( 3 ) is selected from natural rubber, chloroprene rubber, ethylene-propylene terpolymer, ethylene-propylene rubber, polyurethane, butyl rubber, nitrile rubber, silicone rubber, thermoplastic elastomers and mixtures thereof. Use of the elastomer profile according to one of Claims 10 to 13 or of an elastomer profile produced by a process according to one of Claims 1 to 9 ( 1 ) as a squeegee for windshield wipers of motor vehicles or for Scheibenabzieher, as a door seal, as a windshield seal, as a window seal in vehicles, as Elastomerdichteinsatz, as an elastomer sealing profile, as an O-ring or elastomeric profile.