DE102010037328A1 - Pneumatic vehicle tire of radial design comprises carcass, components adjacent to it, and thread-like elements on one of two surfaces of carcass, that discharges air enclosed between carcass and adjacent components during tire construction - Google Patents

Abstract

Pneumatic vehicle tire (1) of radial design comprises a carcass (4), components adjacent to carcass, and thread-like elements arranged on at least one of the two surfaces of carcass, which discharges air enclosed between the carcass and the adjacent components during the tire construction. At least one of the thread-like elements is a thread-like hybrid element comprising a first thread-like element for air discharge and a second thread-like element with an electrically conductive coating (15). The thread-like hybrid element exhibits an electrical resistance of less than 1x 10 7>Ohm/10 cm.

Description

The invention relates to a radial type vehicle pneumatic tire with a carcass and with components adjacent to the carcass, wherein thread-like elements are arranged on at least one of the two surfaces of the carcass, which are preferably used during the tire construction air removal of trapped air between the carcass and the adjacent components ,

Radial tires with thread-like elements for air removal (so-called air discharge threads) are sufficiently known to the person skilled in the art. Such a pneumatic vehicle tire is for example from the DE 3014 268 A1 known. Radial tires are characterized by a radial course of the carcass strength beams. The carcass is made in a textile calender by wrapping the insert with a blend of rubber.

In order to prevent the formation of air between adjacent components and thus reduce the quality of the tire in the tire building, the component carcass after its manufacture in the textile calender on the surface of the mixture layer is covered with thread-shaped, parallel to each other elements for air discharge. This assignment can be done on one side, so only on one of the two surfaces of the carcass, or both sides on both surfaces of the carcass. The assignment with the filamentary air-discharging elements, which are not or not sufficiently electrically conductive, usually takes place at a distance of 25 to 40 mm. The air-discharging elements are, for example, cotton threads with a diameter of 0.05-1 mm. In the tire, the thread-like elements for air discharge in the radial direction and span the full carcass ply width.

In order to be able to derive the electrostatic charge which occurs during operation of the tire, the head area in contact with the road surface including the tread, the bead area in contact with the tire rim and at least one component such as the inner layer, carcass or sidewall, which form the tread and the tread Bülstbereich interconnects, designed electrically conductive. This can be done for example by the use of electrically conductive rubber mixtures. Electrically conductive means that the tire has an electrical resistance of at most 1 × 10 ⁸ ohms.

Now the development is going to reduce the rolling resistance of the tire. One approach to reduce rolling resistance is the use of low-rolling mixtures. These are preferably used as so-called "body mixtures" in the sidewall region, for the inner layer and the carcass. The hysteresis of these low-rolling mixtures can be reduced, inter alia, by the replacement of soot by silica. However, the use of these low-rolling mixtures leads to an increase in the electrical resistance of these mixtures, so that the electrical conductivity decreases. The required electrical resistance of the entire tire of 1 × 10 ⁸ ohms to dissipate the electrostatic charge can not be ensured.

From the previously unpublished DE 10 2010 017 444.0 It is known to the Applicant to provide at least some of the air exhaustion threads with an electrically conductive coating in order to improve the electrical conductivity in the tire. However, this has the disadvantage that the coated air discharge thread lose its original function of air removal by an air-impermeable coating and thus the manufacturing quality of the tire can be adversely affected.

The invention has for its object to provide a low-cost, high quality pneumatic vehicle tire, which has improved electrical conductivity with simple measures.

The object is achieved according to the features of claim 1, characterized in that at least one of these thread-like elements is a thread-like hybrid element, which consists of a first thread-shaped element for air discharge and a second thread-like element with an electrically conductive coating and that the filament-shaped hybrid element has an electrical resistance of <1 × 10 ⁸ ohms / 10 cm.

It is essential to the invention that the thread-like element is a hybrid element which consists of a separate filamentary air-discharging element and of a further separate filamentary element with an electrically conductive coating, by which the required electrical conductivity is ensured. It has been found that a coating of a thread-like element is completely sufficient to obtain the desired and required electrical conductivity of the tire with a maximum total resistance of 1 × 10 ⁸ ohms. Thus, a hybrid element is created, which unites two functions: on the one hand, the air discharge, on the other hand, the electrical conductivity. By this cost-effective measure, a high-quality pneumatic vehicle tire is provided which has improved electrical conductivity with simple measures.

It is ensured that the discharge of the electrostatic charge from the rim over the Bead is improved over the electrically conductive elements to the electrically conductive head portion, even if none of the lateral region of the tire bridging rubber compounds has sufficient electrical conductivity.

The term "coating" means an envelope, coating or film around the filamentary element.

The term "thread-like element" means a textile thread, yarn or cord as such, preferably an air release thread, without an electrically conductive coating. The term "head area" means the components tread, belt and belt bandage of the tire and those intermediate layers which are arranged between these components.

It is useful if the first and the second thread-like element of electrically non-conductive materials such as cotton, nylon, z. As PA6, PA6.6, PA10.10 or polyester, z. B. PET exist. However, it is essential that the air-removing thread-like element consists of a material which allows the air discharge. Therefore, the air-releasing thread-like element is preferably made of cotton.

It is advantageous if the first and the second thread-like element are end-twisted together, so that the filament-shaped hybrid element has a final twist of 1-1000 tpm, preferably 10-100 tpm, more preferably 20-50 tpm. By this final twist, the thread-like element has a sufficient extensibility and therefore does not fracture during tire manufacture and in the operating condition of the tire, which would lead to an interruption of the route.

It is expedient if the first or the second thread-like element has a titre of 50-3000 dtex, preferably of 100-1000 dtex, particularly preferably of 200-500 dtex. The thread-like elements are designed comparatively thin, so that the exterior of the tire and its performance is not changed undesirable.

The filamentary hybrid element may be disposed on the outer surface or on the inner surface or both on the outer surface and on the inner surface of the carcass, also alternating on both surfaces.

"Outer surface" means the surface of the carcass facing the sidewall, while "inner surface" means that surface of the carcass facing the inner layer.

In an advantageous development of the invention, to ensure or improve the electrical conductivity, it is provided that between 1 and 20, preferably between 2 and 6 thread-like hybrid elements on the surface (s) of the carcass, preferably distributed regularly over the carcass width, also alternately on the outside and inner surface, are arranged.

In a further advantageous embodiment of the invention, it is provided that the electrically conductive coating is an adhesion promoter, preferably an RFL-dip, the electrically conductive particles, preferably carbon black with a specific surface ≥ 50 m ² / g, such as type N339 carbon black , particularly preferably contains carbon black with a specific surface ≥ 100 m ² / g. It is known to the person skilled in the art to coat a thread-like element for good rubber bonding with a bonding agent. If now electrically conductive particles, preferably dispersed, are added to this adhesion promoter, the electrical conductivity as well as the desired adhesion promotion as well as a good adhesion of the carbon black to the thread-like element are given. Without requiring a further working step, the electrically conductive and adhesion-promoting coating of the thread-like element is obtained by the customary so-called "dip process" of the thread-like element, in which this adhesive is drawn through the dispersed, electrically conductive particles. This is inexpensive and efficient.

The abbreviation "RFL" stands for resorcinol-formaldehyde latex. The term "adhesion promoter" is understood to mean the adhesion-promoting coating applied to the reinforcement or to its components.

The thread-like elements of the hybrid element may consist of continuous filaments, textured filaments or staple fibers.

It is advantageous if the coating in relation to the bare filamentary element is between 10 and 90% by weight, preferably between 10 and 50% by weight, more preferably between 15 and 35% by weight of the filamentary element [DPU (dip pick-up)]. A DPU between 15 and 35% by weight ensures sufficient electrical conductivity with a comparatively thin and therefore cost-efficient coating that can be applied in a dip process.

In a preferred embodiment, the pneumatic vehicle tire has a head portion and bead portions of electrically conductive rubber blends while the rubber compound (s) of the carcass and / or sidewall portion and / or the inner layer is insufficiently electrically conductive / are. Despite the use of rolling resistance-optimized, "poorly" electrically conductive rubber mixtures in the sidewall region and / or in the carcass and / or in the inner layer, improved electrical conductivity is achieved by the electrically conductive design of fewer air removal threads through its electrically conductive coating. This ensures that the discharge of the electrostatic charge from the rim over the bead on the electrically conductive elements to the electrically conductive tread is sufficient. Nevertheless, the pneumatic vehicle tire is of high manufacturing quality, since the air trapped between the components during tire building can still be reliably discharged via the air-discharging elements of the hybrid elements. Elaborate design measures on the pneumatic vehicle tire are not required.

By "insufficiently electrically conductive rubber compounds" is meant mixtures with which the tire has an electrical electrical resistance of> 1 × 10 ⁸ ohms.

Virtually any combination of polymer-based latex and carbon black or polymer-containing solvent and carbon black, which leaves a conductive film consisting of polymer and carbon black after drying off water or solvent on the non-conductive filamentary element as support, can be used as the conductive dip.

The invention will now be explained in more detail with reference to three figures, which illustrate schematic embodiments. The show:

1 a radial section through a pneumatic vehicle tire;

2 a plan view of a portion of a filamentary hybrid element;

3 a cross-section through the filamentary hybrid element of 2 ,

The 1 shows a radial section through a passenger car pneumatic tire. The pneumatic tire made of rubber compounds 1 has a bulge area 2 to bead area 3 extending radial carcass 4 , which consists of a rubber-embedded insert made of reinforcements and tensile-resistant bead cores 5 from axially inside to axially outside in a carcass turn-up 8th is ended around. The pneumatic vehicle tire 1 still has a tread 6 and to the carcass 4 adjacent components such as the inner layer 9 and the side wall 10 on. Between the carcass 4 and the tread is the belt 7 arranged. The inner layer 9 adjoins the inner surface of the carcass 4 while the sidewall 10 to the outer surface of the carcass 4 borders. On at least one of the two surfaces of the carcass 4 are thread-like elements in the form of air discharge threads 11 made of cotton or PET of construction from 50 to 500 dtex. The air drainage threads 11 serve to trap the trapped air between the carcass during tire building 4 and the adjacent components inner layer and / or side wall 9 . 10 dissipate. The air drainage threads 11 are at a distance of 25 to 40 mm - measured in the circumferential direction - on the surface of the carcass 4 arranged in radial orientation and have a diameter of <0.3 mm, preferably from 0.05 to 0.2 mm. The air drainage threads 11 span the full carcass ply width.

Between 2 and 6 pieces of air exhaustion threads 11 of the tire are filamentous hybrid elements 12 made of two twisted thread-like elements 13 . 14 , wherein the first thread-like element 13 for air discharge and the second thread-like element 14 an electrically conductive coating 15 has and the electrical line is used, see. 2 and 3 , The filamentous hybrid elements 12 are regularly distributed over the circumference of the tire on the carcass 4 arranged.

The filamentous hybrid element 12 consists of a first thread-like element 13 for air discharge and a second thread-like element 14 with an electrically conductive coating 15 , The filamentous hybrid element 12 has an electrical resistance of <1 × 10 ⁷ ohms / 10 cm. The first thread-like element 13 and the second filamentary element, without its coating, are yarns 17 . 18 Made of electrically non-conductive cotton. The yarns 17 . 18 are end-twisted with 100 tpm each other. Each of the two yarns 17 . 18 has a titer of 235 dtex. The electrically conductive coating 15 of the second thread-like element 14 is in relation to the plain thread-like yarn 17 between 20 to 40% by weight of the filamentary element 14 , The electrically conductive coating 15 is an RFL-dip (resorcinol-formaldehyde-latex-dip) having carbon blacks with a specific surface ≥ 50 m ² / g, which has a carbon black content of 15 to 50% by weight, preferably a carbon black content of 20 to 40% by weight in the dried state , This so-called soot-containing RFL dip ensures the electrical conductivity and at the same time allows a good bond to rubber and a good adhesion of the carbon black to the thread-like element 14 , The filamentous hybrid elements 12 as well as the other air discharge threads 11 are over the entire axial width of the carcass 4 arranged.

LIST OF REFERENCE NUMBERS

1

Vehicle tires

2

bead

3

bead

4

carcass

5

bead

6

tread

7

belt

8th

a carcass

9

inner layer

10

Side wall

11

Air discharge thread (thread-like element)

12

Thread-shaped hybrid element

13

Air-releasing thread-like element

14

filiform coated element

15

electrically conductive coating

16

electrically conductive particles

17

yarn

18

yarn

aR

axial direction

rR

radial direction

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

• DE 3014268 A1 [0002]
• DE 102010017444 [0006]

Claims (9)

Pneumatic vehicle tire ( 1 ) in radial construction with a carcass ( 4 ) and to the carcass ( 4 ) adjacent components ( 9 . 10 ), wherein on at least one of the two surfaces of the carcass ( 4 ) thread-like elements ( 11 ) are arranged, which preferably during the tire construction of a discharge of trapped air between the carcass ( 4 ) and the adjacent components ( 9 . 10 ), wherein at least one of these thread-like elements ( 11 ) a filamentous hybrid element ( 12 ), which consists of a first thread-like element ( 13 ) for air discharge and a second thread-like element ( 14 ) with an electrically conductive coating ( 115 ) and wherein the filamentous hybrid element ( 12 ) has an electrical resistance of <1 × 10 ⁷ ohms / 10 cm. Pneumatic vehicle tire according to claim 1, characterized in that the first and the second filiform element ( 13 . 14 ) consist of electrically non-conductive materials such as cotton, nylon or polyester. Pneumatic vehicle tire according to claim 1 or 2, characterized in that the first and the second filiform element ( 13 . 14 ) are end-twisted with each other, so that the thread-like hybrid element ( 12 ) has a final twist of 1-1000 tpm, preferably 10-100 tpm, more preferably 20-50 tpm. Pneumatic vehicle tire according to one or more of the preceding claims, characterized in that the first or the second filiform element ( 13 . 14 ) has a linear density of 50-3000 dtex, preferably 100-1000 dtex, more preferably 200-500 dtex. Pneumatic vehicle tire according to one or more of the preceding claims, characterized in that between one and 20, preferably between two and 6, electrically conductive thread-like hybrid elements ( 12 ) on the surface (s) of the carcass ( 4 ) are arranged. Pneumatic vehicle tire according to one or more of the preceding claims, characterized in that the electrically conductive coating ( 15 ) an adhesion promoter, preferably an RFL-dip, the electrically conductive particles ( 16 ), preferably carbon black having a specific surface area ≥ 50 m ² / g, particularly preferably having a specific surface area ≥ 100 m ² / g. Pneumatic vehicle tire according to claim 7, characterized in that the electrically conductive coating ( 15 ) is a carbon black dip. Pneumatic vehicle tire according to one or more of the preceding claims, characterized in that the electrically conductive coating ( 15 ) with respect to the second filiform element ( 14 ) is between 10 and 90% by weight, preferably between 10 and 50% by weight, more preferably between 15 and 35% by weight. Pneumatic vehicle tire according to one or more of claims 1-11, characterized in that the rubber mixtures of the head region ( 6 ) and the bead areas ( 2 . 3 ) of the pneumatic vehicle tire ( 1 ) have electrically conductive rubber compounds, while the rubber mixture (s) of the carcass ( 4 ) and / or the sidewall region ( 10 ) and / or the inner layer ( 9 ) is insufficiently electrically conductive / are.

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