Self-Sealing Vehicle Tyre

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 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.

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 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 at least the surface of the sealant layer running essentially parallel to the belt package in axial direction has a circumferential coating that comprises at least one alkali metal salt of at least one fatty acid, at least one alkaline earth metal salt of at least one fatty acid, or 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.

12. The self-sealing pneumatic vehicle tire as claimed in claim 11, wherein the coating 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.

13. The self-sealing pneumatic vehicle tire as claimed in claim 11, wherein the fatty acid has from 8 to 18 carbon atoms.

14. The self-sealing pneumatic vehicle tire as claimed in claim 11, wherein at least calcium stearate is present in the coating as alkaline earth metal salt of at least one fatty acid.

15. The self-sealing pneumatic vehicle tire as claimed in claim 11, wherein the coating has a thickness of from 0.01 to 1 mm

16. The self-sealing pneumatic vehicle tire as claimed in claim 11, wherein at least the surface running in radial direction additionally has the coating.

17. The self-sealing pneumatic vehicle tire as claimed in claim 16, wherein the coating has been applied to the surface of the sealant layer such that there is an overlap with the inner layer on either side in axial direction.

18. The self-sealing pneumatic vehicle tire as claimed in claim 17, wherein the axial width of the overlap on each side is from 0.5 to 10 mm.

19. The self-sealing pneumatic vehicle tire as claimed in claim 11, wherein the surface of the inner layer directed radially inward additionally has the coating.

20. The self-sealing pneumatic vehicle tire as claimed in claim 19, wherein the coating on the surface of the inner layer directed radially inward extends from the sealant layer on either side as far as the radially outer end of an extent of a bead core.

Description

[0055] 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.

[0056] 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 layers 2a, 2b in the execution shown, a single-ply carcass 3 which is guided around the bead cores 8 and bead fillers 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 yarns 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.

[0057] The sealant layer 5, in the example in FIG. 1, on the surface 5a running essentially parallel to the belt package in axial direction and additionally on the surface 5b running essentially in radial direction, has the coating 6 containing 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, the coating 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.

[0058] In addition, the coating overlaps the inner layer on either side in axial direction, where the overlap 7

at each side is 0.5 to 10 mm, preferably 0.5 to 2 mm, more preferably, for example, 1 mm.

[0059] The thickness of the coating 6 is preferably 0.01 to 1 mm, especially and for example 0.05 to 0.15 mm, more preferably 0.1 mm.

[0060] 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 containing 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, to all the exposed surfaces of the sealant layer and a region of the inner layer on each side in axial direction of width 0.5 to 10 mm, preferably 0.5 to 2 mm, more preferably, for example, 1 mm, and drying it.

[0061] The sealant layer 5, in the example in FIG. 2, on the surface 5a running essentially parallel to the belt package in axial direction and additionally on the surface 5b running essentially in radial direction and additionally on the surface of the inner layer 4a directed radially inward, has the coating 6 containing 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.

[0062] The coating 6 has been applied to the inner layer 4a, for example and with preference, such that it extends, on the surface of the inner layer 4a directed radially inward, from the sealant layer 5 on either side as far as the radially outer end of the extent of the bead core 8a.

[0063] 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 containing 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, to all the exposed surfaces of the sealant layer and the surface of the inner layer exposed in the radially inward direction as far as the radially outward end of the extent of the bead core, and drying it.

LIST OF REFERENCE SIGNS

Part of the Description

[0064] 1 Tread [0065] 2 Belt package [0066] 2a Belt ply [0067] 2b Belt ply [0068] 3 Carcass [0069] 3a Carcass turnup [0070] 4 Inner layer [0071] 4a Surface of the inner layer directed radially inward [0072] 5 Sealant layer [0073] 5a Surface of the sealant layer directed radially inward, running in axial direction, essentially parallel to the belt package [0074] 5b Surface of the sealant layer running in radial direction, essentially at right angles to the belt package [0075] 6 Coating [0076] 7 Overlap [0077] 8 Bead core [0078] 8a Radially outer end of the extent of the bead core [0079] 9 Bead filler [0080] 10 Side wall [0081] rR Radial direction [0082] aR Axial direction