SELF-SEALING PNEUMATIC VEHICLE TYRE AND METHOD FOR THE PRODUCTION THEREOF

Abstract

The invention relates to a self-sealing pneumatic vehicle tire having a belt package (2), a tread (1) arranged radially above the belt package (2) and an airtight inner layer (4) arranged radially on the inside, wherein the self-sealing of the pneumatic vehicle tire is obtained via a sealant layer (5) subsequently applied radially on the inside after the vulcanization of the pneumatic vehicle tire, wherein the sealant layer (5) has essentially the width of the belt package (2) and is arranged essentially in the projection thereof and has a cross section which is formed in a cross-sectional plane including the tire axis and has a surface (5a) running essentially parallel to the belt package in axial direction and a surface (5b) running essentially in radial direction.

It is a feature of the invention that at least the surface of the sealant layer (5a) running essentially parallel to the belt package in axial direction has a circumferential coating (6) that contains at least elastomer particles.

In the method of the invention, the sealant layer is coated at least with elastomer particles.

Claims

1.-10. (canceled)

11. A self-sealing pneumatic vehicle tire comprising a belt package, a tread arranged radially above the belt package and an airtight inner layer arranged radially on the inside; wherein the self-sealing of the pneumatic vehicle tire is obtained via a sealant layer subsequently applied radially on the inside after the vulcanization of the pneumatic vehicle tire; wherein the sealant layer has essentially the width of the belt package and is arranged essentially in the projection thereof and has a cross section which is formed in a cross-sectional plane including the tire axis and has a surface running essentially parallel to the belt package in axial direction and a surface running essentially in radial direction; and, wherein the at least the surface of the sealant layer running essentially parallel to the belt package in axial direction has a circumferential coating that contains at least elastomer particles.

12. The self-sealing pneumatic vehicle tire as claimed in claim 1, wherein the elastomer particles have a particle size of 0.05 to 2 mm.

13. The self-sealing pneumatic vehicle tire as claimed in claim 1, wherein the elastomer particles are based on natural polyisoprene and/or synthetic polyisoprene and/or polybutadiene and/or styrene-butadiene copolymer and/or butyl rubber and/or halobutyl rubber and/or nitrile-butadiene rubber and/or hydrogenated acrylonitrile-butadiene rubber and/or ethylene-propylene-diene rubber.

14. The self-sealing pneumatic vehicle tire as claimed in claim 1, wherein the elastomer particles comprise at least one regenerated rubber material.

15. The self-sealing pneumatic vehicle tire as claimed in claim 1, wherein the coating additionally contains at least one alkali metal salt of at least one fatty acid and/or at least one alkaline earth metal salt of at least one fatty acid.

16. The self-sealing pneumatic vehicle tire as claimed in claim 1, wherein at least the surface running in radial direction additionally has the coating.

17. A method of producing a self-sealing pneumatic vehicle tire comprising a belt package, a tread arranged radially above the belt package and an airtight inner layer arranged radially on the inside; wherein the self-sealing of the pneumatic vehicle tire is obtained via a sealant layer subsequently applied radially on the inside after the vulcanization of the pneumatic vehicle tire; wherein the sealant layer has roughly the width of the belt package and is arranged roughly in the projection thereof and has a cross section which is formed in a cross-sectional plane including the tire axis and has a surface running essentially parallel to the belt package in axial direction and a surface running essentially in radial direction; and, wherein the sealant layer has been coated at least with elastomer particles.

18. The method as claimed in claim 17, wherein the elastomer particles are applied with a spray gun.

19. The method as claimed in claim 17, wherein the elastomer particles are applied in an aqueous suspension of at least one alkali metal salt of at least one fatty acid and/or of at least one alkaline earth metal salt of at least one fatty acid.

20. The method as claimed in claim 19, wherein the application is effected with a spray gun or a rotating spray turntable.

Description

[0070] Further features, advantages and details of the invention will be discussed in detail with reference to FIGS. 1 and 2, which illustrate schematic working examples.

[0071] The essential constituents of which the self-sealing tire of the invention is composed are a profiled tread 1, a belt package 2 that consists of two plies 2a, 2b in the execution shown, a single-ply carcass 3 which is guided around the bead cores 8 and bead core profiles 9 from the inside outward in axial terms and ends in the carcass turnup 3a, and side walls 10. The two plies 2a, 2b of the belt package 2 consist of reinforcing elements of steel cord that are embedded in a rubber compound and run parallel to one another within each ply, the steel cords of the one ply 2a being oriented in a crossing arrangement in relation to the steel cords of the second ply 2b and each forming an angle between 15 and 45 with the circumferential direction of the tire. The single-ply carcass 3 may also be formed in a conventional and known way, and consequently have reinforcing fibers of a textile material or of steel cord that are embedded in a rubber compound and run in the radial direction. The self-sealing of the pneumatic vehicle tire is obtained by means of a sealant layer 5 subsequently applied circumferentially on the inside in radial direction after the vulcanization of the pneumatic vehicle tire. The sealant layer 5 has essentially the width of the belt package 2 and is arranged essentially in the projection thereof and has a cross section which is formed in the cross-sectional plane including the tire axis and has a surface 5a running essentially parallel to the belt package in axial direction and a surface 5b running essentially in radial direction. The surface 5b is present on either side in axial direction and thus constitutes the lateral boundaries of the sealant layer around the circumference.

[0072] The sealant layer 5, according to the example in FIG. 1, on the surface 5a directed radially inward, has a coating 6 containing at least elastomer particles, for example with a particle size of 0.35 to 0.55 mm.

[0073] For example, the coating additionally contains at least one alkali metal salt of at least one fatty acid and at least one alkaline earth metal salt of at least one fatty acid, where the alkaline earth metal salt of at least one fatty acid is at least calcium stearate. For example, the fatty acid is selected from the group consisting of octanoic acid and/or tetradecanoic acid and/or hexadecanoic acid and/or octadecanoic acid.

[0074] A self-sealing pneumatic vehicle tire of this kind can be obtained, for example, by first producing the pneumatic vehicle tire and then applying the sealant layer as known in the prior art and then applying an aqueous suspension comprising regenerated rubber material having an average particle size of 0.42 mm and at least one alkali metal salt of at least one fatty acid and/or at least one alkaline earth metal salt of at least one fatty acid, for example Rhenodiv BO 7672-1 from Rheinchemie, with a spray gun and drying it. Prior to application, the regenerated rubber material is mixed here into the suspension described, for example Rhenodiv BO 7672-1. The weight ratio of regenerated rubber material to the suspension prior to the mixing-in is, for example, 1:3.

[0075] The coating of the surface 5a in the example according to FIG. 1 may alternatively contain elastomer particles only, such as preferably regenerated rubber material from used tires. The particles are likewise applied with a spray gun having suitable nozzle diameter.

[0076] The sealant layer 5, in the example in FIG. 2, on the surface 5a running in axial direction essentially parallel to the belt package and additionally on the surface 5b running essentially in radial direction, has the coating 6 comprising at least elastomer particles. The details described for FIG. 1 are applicable, where the coating additionally comprises at least one alkali metal salt of at least one fatty acid and at least one alkaline earth metal salt of at least one fatty acid.

[0077] In addition, the coating, by virtue of the production method, overlaps the inner layer on either side in axial direction, where the overlap 7 on each side is 0.5 to 10 mm, preferably 0.5 to 2 mm, more preferably, for example, 1 mm.

[0078] A self-sealing pneumatic vehicle tire of this kind can be obtained as described in FIG. 1, where at least the surfaces 5a and 5b are coated by applying the elastomer particles in the aqueous suspension mentioned with a spray gun.

LIST OF REFERENCE NUMERALS

Part of the Description

[0079] 1 Tread [0080] 2 Belt package [0081] 2a Belt ply [0082] 2b Belt ply [0083] 3 Carcass [0084] 3a Carcass turnup [0085] 4 Inner layer [0086] 4a Surface of the inner layer directed radially inward [0087] 5 Sealant layer [0088] 5a Surface of the sealant layer directed radially inward, running in axial direction, essentially parallel to the belt package [0089] 5b Surface of the sealant layer running in radial direction, essentially at right angles to the belt package [0090] 6 Coating [0091] 7 Overlap [0092] 8 Bead core [0093] 8a Radially outer end of the extent of the bead core [0094] 9 Bead core profile [0095] 10 Sidewall [0096] rR Radial direction [0097] aR Axial direction