Reinforcement Layer and Pneumatic Vehicle Tire

Abstract

The invention relates to a reinforcement layer for elastomeric products, in particular for the belt bandage (8), having cords as reinforcement, where the cords have at least two yarns, where a first yarn of the yarns is made of polyamide and where the ends of all yarns of a cord are twisted together. The problem addressed by the invention is that of providing a reinforcement layer for elastomeric products which exhibits a relatively high tensile force value for an elongation of 4% or more and which exhibits relatively low shrinkage based on linear density of the reinforcement. This is achieved in that the cords are hybrid cords having precisely three yarns, in that the hybrid cord has the first yarn and a second yarn made of HMLS-PET, in that the hybrid cord has a first yarn or a second yarn as third yarn, and in that the linear density of each hybrid cord is at least 5000 dtex.

Claims

1.-10. (canceled)

11. A reinforcement layer for a belt bandage comprising: cords as reinforcement which are arranged within the reinforcement layer parallel to one another and are embedded into elastomeric material, where the cords have at least two yarns, where a first yarn of the yarns is made of polyamide and where the ends of all yarns of a cord are twisted together, wherein; the cords are hybrid cords, each of the hybrid cords has precisely three yarns, the three yarns are composed of the first yarn made of polyamide, a second yarn made of high-modulus low-shrinkage polyethylene terephthalate (HMLS-PET) and a third yarn, the third yarn is configured as the first yarn or as the second yarn and the linear density of each hybrid cord is at least 5000 dtex.

12. The reinforcement layer as claimed in claim 11, wherein the first yarn is a yarn made of polyamide 6.6.

13. The reinforcement layer as claimed in claim 11, wherein two yarns of the hybrid cord are configured identically in their material and in their linear density.

14. The reinforcement layer as claimed in claim 11, wherein the linear density of each of the three yarns of the hybrid cord is respectively 1000 dtex to 3000 dtex, preferably 1000 dtex to 2500 dtex, particularly preferably 1500 dtex to 2200 dtex.

15. The reinforcement layer as claimed in claim 11, wherein the hybrid cords are arranged with a thread density of 50 epdm to 90 epdm, preferably 60 epdm to 80 epdm, within the reinforcement layer.

16. The reinforcement layer as claimed in claim 11, wherein the hybrid cords have the structure polyamide 6.6 21002+PET 22001 and are arranged with a thread density of 70 epdm to 90 epdm within the reinforcement layer.

17. The reinforcement layer as claimed in claim 11, wherein the hybrid cords have the structure polyamide 6.6 21001+PET 22002 and are arranged with a thread density of 50 epdm to 70 epdm within the reinforcement layer.

18. A pneumatic tire, comprising: at least one reinforcement layer having cords as reinforcement which are arranged within the at least one reinforcement layer parallel to one another and are embedded into elastomeric material, where the cords have at least two yarns, where a first yarn of the yarns is made of polyamide and where the ends of all yarns of a cord are twisted together, wherein; the cords are hybrid cords, each of the hybrid cords has precisely three yarns, the three yarns are composed of the first yarn made of polyamide, a second yarn made of high-modulus low-shrinkage polyethylene terephthalate (HMLS-PET) and a third yarn, the third yarn is configured as the first yarn or as the second yarn; and the linear density of each hybrid cord is at least 5000 dtex.

19. The pneumatic tire as claimed in claim 18, wherein the at least one reinforcement layer is configured for a belt bandage.

20. The pneumatic tire as claimed in claim 18, wherein the at least one reinforcement layer is configured for a bead reinforcement.

21. The pneumatic tire as claimed in claim 18, wherein the at least one reinforcement layer is configured as single reinforcement layer of a belt bandage.

22. A pneumatic tire, comprising: a single reinforcement layer of a belt bandage proximate a tread and having a plurality of cords arranged within the single reinforcement layer parallel to one another and embedded into elastomeric material, where the plurality of cords have at least two yarns; and wherein each of the plurality of cords has precisely a first yarn made of polyamide, a second yarn made of high-modulus low shrinkage polyethylene terephthalate (HMLS-PET) and a third yarn.

23. The pneumatic tire of claim 22, wherein each of the plurality of cords have the structure polyamide 6.6 21002+HMLS-PET 22001 with a thread density of 80 epdm.

24. The pneumatic tire of claim 22, wherein each of the plurality of cords have the structure polyamide 6.6 21001+HMLS-PET 22002 with a thread density of 60 epdm.

25. The pneumatic tire of claim 22, wherein the third yarn is configured identical to the second yarn.

26. The pneumatic tire of claim 22, wherein the belt bandage is a single layer.

27. The pneumatic tire of claim 22, wherein the single reinforcement layer is configured at an angle between 0 and 5 to a circumferential direction.

28. The pneumatic tire of claim 27, wherein the single reinforcement layer is coiled in circumferential direction in the form of a single layer to facilitate ultra high speed functionality and mitigate flattening effects.

29. The pneumatic tire of claim 22, further comprising a bead layer having a bead reinforcement layer, wherein the bead reinforcement layer comprises a plurality of cords arranged within the single reinforcement layer parallel to one another and embedded into elastomeric material, where the plurality of cords have at least two yarns; wherein each of the plurality of cords has precisely a first yarn made of polyamide, a second yarn made of high-modulus low shrinkage polyethylene terephthalate (HMLS-PET) and a third yarn.

Description

[0038] Further features, advantages and details of the invention will now be explained in more detail with reference to the diagrams, which represent working examples. In the drawings:

[0039] FIG. 1 shows a radial cross section through a pneumatic tire of the invention;

[0040] FIG. 2 shows a force/elongation curve of reinforcement layers.

[0041] FIG. 1 shows a radial cross section through a pneumatic tire for a car. The essential components of which the depicted pneumatic vehicle tire is composed are a substantially air-impermeable internal layer 1, a carcass 2 which in conventional manner reaches from the region of the crown of the pneumatic vehicle tire by way of the sidewalls 3 into the bead regions 4 and is anchored there by wrapping around tension-resistant bead cores 5, a profiled tread 6 located radially outside the carcass and a belt 7 arranged between the tread 6 and the carcass 2 and comprising two reinforcement layers which is radially covered on the outside by the belt bandage 8, which comprises at least one reinforcement layer. The belt bandage 8 covers the belt edges 9 and comprises reinforcement elements wound parallel in circumferential direction of the pneumatic tire along the axial width and embedded into elastomeric material. The pneumatic tire further comprises a bead reinforcement 10. The bead reinforcement 10 is arranged entirely or to some extent within the bead region 4. The bead reinforcement 10 is positioned axially outside and connected to the carcass 2. The bead reinforcement 10 comprises at least one reinforcement layer which runs around the tire in circular form in the region of the bead.

[0042] The tire of the invention can comprise a reinforcement layer, designed in the invention, of the belt bandage 8 and/or a reinforcement layer, designed in the invention, of the bead reinforcement 10. The tire can also be designed without bead reinforcement 10 and only with belt bandage 8 of the invention. It is preferable that each of the components 8, 10 mentioned comprises precisely one reinforcement layer.

[0043] If the tire comprises precisely one reinforcement layer of the invention as single reinforcement layer of the belt bandage 8, this tire has particularly good suitability for ultrahigh-speed use, together with low rolling resistance and good dimensional stability.

[0044] The reinforcement layer 8, 10 has hybrid cords as reinforcement. Each of the hybrid cords has precisely three yarns, the ends of which have been twisted together to form the hybrid cord. The three yarns are a first yarn made of polyamide, a second yarn made of high-modulus low-shrinkage polyethylene terephthalate (HMLS-PET) and a third yarn. The third yarn is either a first yarn made of polyamide or a second yarn made of HMLS-PET. The linear density of each hybrid cord here is at least 5000 dtex.

[0045] The polyamide can be PA 6.6. The linear density of each of the three yarns of the hybrid cord can be 1000 dtex to 3000 dtex, preferably 1000 dtex to 2500 dtex, particularly preferably 1500 dtex to 2200 dtex. The hybrid cords can be arranged with a thread density of 50 epdm to 90 epdm, preferably 60 epdm to 80 epdm, within the reinforcement layer.

[0046] The hybrid cords are treated with an adhesive impregnation system, for example an RFL dip.

[0047] In a first working example, the hybrid cords have the structure polyamide 6.6 21002+HMLS-PET 22001, and are arranged with a thread density of 70 epdm to 90 epdm within the reinforcement layer.

[0048] In a second working example, the hybrid cords have the structure polyamide 6.6 21001+HMLS-PET 22002, and are arranged with a thread density of 50 epdm to 70 epdm within the reinforcement layer.

[0049] FIG. 2 shows force/elongation curves determined in accordance with ASTM D885 M of reinforcement layers. The horizontal axis shows the elongation D in percent, and the vertical axis shows force F in Newtons per decimeter of reinforcement layer (perpendicularly to the direction in which the reinforcement layer extends).

[0050] Force/elongation curves are depicted for the first working example and for the second working example. The dotted line represents the reinforcement layer of the invention with hybrid cords having the structure polyamide 6.6 21002+HMLS-PET 22001 with a thread density of 80 epdm. The dashed line represents the reinforcement layer of the invention with hybrid cords having the structure polyamide 6.6 21001+HMLS-PET 22002 with a thread density of 60 epdm. A continuous line moreover, as reference, represents the force/elongation curve of a two-layer structure where each reinforcement layer of the two-layer structure comprises, as reinforcement, cords having the structure PA 6.6 14402 with a thread density of 110 epdm. This type of two-layer structure is usual for the belt bandage in ultrahigh-speed use.

[0051] It can be seen that, up to an elongation of about 4%, the inventive reinforcement layers of the two working examples exhibit, for the use in the belt bandage of a pneumatic tire, force/elongation behavior that is similarly advantageous to that of the two-layer reference example. Very surprisingly, it can moreover be seen that with increasing elongation the single-layer working examples of the invention actually exhibit an advantageous steeper force/elongation curve than the two-layer reference example. The reinforcement layers of the first working example and of the second working example have excellent suitability for the use in a single-layer belt bandage of a pneumatic tire as shown in FIG. 1.

LIST OF REFERENCE SIGNS

Part of the Description

[0052] 1 Internal layer [0053] 2 Carcass [0054] 3 Sidewall [0055] 4 Bead region [0056] 5 Bead core [0057] 6 Tread [0058] 7 Belt [0059] 8 Belt bandage [0060] 9 Belt edge [0061] 10 Bead reinforcement [0062] aR Axial direction [0063] rR Radial direction [0064] U Circumferential direction