DE102023203757A1 - Pneumatic vehicle tires having reinforcement layers - Google Patents

Abstract

Pneumatic vehicle tire, wherein the strength members of the bandage layer have a multifilament yarn made of PA 6.6 with a fineness of 100 dtex to 1500 dtex, the raw yarn of which has a fineness-related maximum tensile strength of greater than 87 cN/tex, and a hot shrinkage of greater than 6%, wherein the strength members of the carcass layer have a multifilament yarn made of PET with a fineness of 50 dtex to 2500 dtex, the raw yarn of which has a fineness-related maximum tensile strength of ≥ 70 cN/tex and a hot shrinkage of less than 8%, and wherein the strength members of the belt layer have a steel filament with a tensile strength of 3000 N/mm^2 to 4100 N/mm^2 and a carbon content of 0.79 wt.% to 1.10 wt.%. Such a pneumatic vehicle tire still has sufficient robustness against special stresses, such as improper use, while still having improved rolling resistance.

Description

The invention relates to a pneumatic vehicle tire, having a carcass having a carcass ply, a belt arranged radially outside the carcass and having a belt layer, and a belt bandage resting radially outside on the belt and having a bandage layer, wherein the carcass ply, the belt layer and the bandage layer each have strength members which are embedded in rubber material within the respective layer, arranged parallel and spaced from one another, wherein the strength members of the bandage layer are textile strength members, each formed from at least one multifilament yarn made of polyamide 6.6 (PA 6.6), wherein the strength members of the carcass ply are textile strength members, each formed from at least one multifilament yarn made of polyethylene terephthalate (PET), and wherein the strength members of the belt layer are each formed from at least one steel filament.

Reinforcing layers for pneumatic vehicle tires, such as the carcass layer, the belt layer and/or the bandage layer, are of great importance and are generally known to those skilled in the art. The reinforcing layers have a large number of reinforcing, thread-like elements, the so-called strength members. The strength members are completely embedded in elastomeric material, for example by calendering. The strength members of these reinforcing layers have, for example, the form of fabrics or calendered, endlessly spooled strength members.

The rubberized reinforcement layers of suitable size and design are joined together with other components to form a pneumatic vehicle tire. In the pneumatic vehicle tire, the reinforcement layers reinforce the respective components of the tire. At the same time, the pneumatic vehicle tire should be improved with regard to other boundary conditions, such as low rolling resistance. This can be achieved by using comparatively thin and high-strength reinforcement layers.

However, the reinforcement layers still have to meet the demanding requirements according to the task of the respective component of the pneumatic vehicle tire. Particularly in areas subject to high levels of stress, the interaction of the reinforcement layers of various components of the tire must be taken into account to ensure sufficient technical properties of the entire tire. For example, in the head area of the pneumatic vehicle tire, in which the reinforcement layers of the carcass, the belt and the belt bandage are arranged to overlap each other at least in sections, not only the required technical properties of the individual components must be taken into account, but the strength and robustness of the entire head area must be guaranteed.

To ensure the strength and robustness of the pneumatic vehicle tire, it is known and common practice to equip the head area of the pneumatic vehicle tire with a sufficient thickness to ensure strength and robustness against exceptional loads such as driving over obstacles. However, this in turn has a negative effect on other properties, such as low rolling resistance.

A pneumatic vehicle tire, in particular of a radial design, generally has a carcass containing at least one carcass ply, the carcass extending from a zenith region of the tire over side walls to bead regions and is usually anchored there by wrapping around tensile bead cores, a profiled tread located radially outside the carcass and a belt arranged between the tread and the carcass, usually having at least two belt layers, and a belt bandage lying radially on the outside of the belt and covering at least the belt edges with at least one bandage layer. In a tire of radial design, the carcass is designed as a radial carcass, with all or some of the strength members of the radial carcass running approximately in the radial direction in an area of the side walls.

In this application, “approximately in” a direction means at an angle of 0° to 8° with respect to the respective direction.

The reinforcements of the carcass, particularly the radial carcass, must be strong enough to be able to adequately absorb the forces that occur during operation of the tire and to be durable. In particular, the carcass must resist the internal pressure of the tire. Driving behavior is also positively influenced, particularly in high-speed use, by a high modulus of elasticity at stretches of up to approx. 2% to 4% of the reinforcements of the carcass. In addition, a reinforcement layer of the carcass during tire manufacture should allow sufficient elevation during tire construction and in the vulcanization mold so that the tire can be precisely formed. In addition, the reinforcements of the carcass should have a high maximum tensile force and a high elongation at break in order to increase the durability of the tire and to have improved durability with regard to forced stretching, such as can occur when driving through a pothole.

The belt bandage serves to prevent the tire from lifting due to the centrifugal forces that occur during driving, particularly during high-speed use. The strength members of the at least one bandage layer of the belt bandage run approximately in the circumferential direction. The at least one bandage layer of the belt bandage is applied during tire production in the form of layers, strips or individual strength members with strength members embedded in an unvulcanized rubber mixture, which are wound or spooled onto the belt. The strength members of the belt bandage should allow sufficient lifting during the cambering and in the vulcanization mold during tire production so that the tire can be precisely formed, and they should ensure good high-speed suitability during driving after the tire has been completed. In order to meet these requirements, the reinforcements should have a breaking elongation sufficient for tire production and should be able to be stretched up to an elongation of approx. 3% to 4% with moderate effort and from a higher elongation only with very high effort.

The belt usually has at least two belt layers that are arranged at an angle to each other. The belt improves the rigidity of the tread in the longitudinal and transverse directions. This serves to transfer power when driving, improves lateral guidance and reduces tire wear.

Efforts are also being made to further improve the properties of the belt bandage. The EP3254870 A1 and EP3254871 A1 each one reinforcement layer of the belt bandage, the strength member of which comprises at least one multifilament yarn made of polyamide 6.6, the raw yarn made of polyamide 6.6 having a fineness-related strength which lies in a range of 1.35 cN/dtex to 1.60 cN/dtex at an elongation of 4%, the strength member having a fineness-related strength which lies in an advantageous range at an elongation of 4%. The comparatively thin reinforcement layers have an elastic modulus which is advantageous for use in the belt bandage and are more fatigue-resistant in relation to alternating pressure and bending stresses.

Efforts to make the carcass ply(s) as thin as possible by using reinforcements made of high-strength PET have been EP 3493999 A1 The document discloses a carcass ply having cords made of two twisted multifilament yarns made of PET as a reinforcement, whereby the raw yarns made of PET have a fineness-related maximum tensile strength of greater than 70 cN/tex and a heat shrinkage of less than 4%, which is sufficient for the carcass.

The EP 3544826 A1 discloses belt layers comprising steel filaments with a tensile strength of 3080 N/mm ² to 4190 N/mm ² as reinforcements. DE10 2019 218 723 A1 discloses a belt layer comprising steel cords of construction 1+2 made of three steel filaments with a tensile strength of 3000 N/mm ² to 4000 N/mm ² of the same diameter.

The development is moving towards further improving the environmental friendliness, in particular the rolling resistance, of rubber products by optimizing the reinforcement layer(s) of a component of the rubber product. By specifically reducing the fineness or diameter of the strength members of a reinforcement layer, the associated reduction in the thickness of the reinforcement layer can reduce energy consumption when the tire component is deformed during operation of the tire. However, such optimization of the reinforcement layer comes at the expense of other properties, such as the robustness of the component. If several components of the tire are to contribute to optimization, the interaction of the individual optimized components in particularly stressed areas of the tire must also be taken into account. This applies, for example, to the head area, in which the reinforcement layers of different components, in particular the carcass, the belt and the belt bandage, work together. The robustness of the entire tire should also be ensured against special stresses, such as those that can arise from improper use, such as driving with insufficient air pressure or overloading.

It was therefore the primary object of the present invention to provide a pneumatic vehicle tire which, while still having a further improved rolling resistance, still has sufficient robustness against special stresses, such as improper use.

The object is achieved by a pneumatic vehicle tire according to the features of claim 1.

The pneumatic vehicle tire according to the invention is characterized in that the multifilament yarn made of PA 6.6 has a fineness of 100 dtex to 1500 dtex, that the raw yarn made of PA 6.6 of the multifilament yarn made of PA 6.6 has a fineness-related maximum tensile force of greater than 87 cN/tex, determined according to ASTM D885, and a hot shrinkage of greater than 6%, determined at 180°C under a pretension of 0.05 cN/dtex with an exposure time of two minutes.

The pneumatic vehicle tire according to the invention is further characterized in that the multifilament yarn made of PET has a fineness of 50 dtex to 2500 dtex and that the raw yarn made of PET of the multifilament yarn made of PET has a fineness-related maximum tensile force of ≥ 70 cN/tex, determined according to ASTM D885, and a hot shrinkage of less than 8%, determined at 180 °C under a pretension of 0.01 cN/dtex with an exposure time of two minutes.

The pneumatic vehicle tire according to the invention is further characterized in that the steel filament has a tensile strength of 3000 N/mm^2 to 4100 N/mm^2, determined according to ASTM D2969, and a carbon content of 0.79 wt.% to 1.10 wt.%.

“Raw yarn” means a multifilament yarn that is spun without any twisting and is therefore not yet hot-drawn and impregnated. A “textile reinforcement” means a reinforcement made of one, two or more multifilament yarns made of a textile material, such as PA 6.6 or PET, whereby the multifilament yarn or yarns have already undergone the process of hot-drawing including impregnation and twisting. In the case of a textile reinforcement made of two or more multifilament yarns, the two or more multifilament yarns can be twisted together at the end to form a cord.

Physical measurement variables, in particular physical measurement variables of the textile reinforcements and/or the multifilament yarns of the textile reinforcements and/or the raw yarns of the multifilament yarns and/or the steel reinforcements and/or the steel filaments of the steel reinforcements, can be determined before embedding the respective reinforcement in the respective reinforcement layer of the pneumatic vehicle tire.

The force-elongation data for determining the fineness-related maximum tensile force of the raw yarns or the textile reinforcements as well as the fineness-related strength at 4% elongation of the raw yarns or the textile reinforcements are each determined in accordance with ASTM D885.

The heat shrinkage of the raw yarns or the textile reinforcements is determined at 180 °C under a pre-tension with an exposure time of two minutes. For PET, the pre-tension is 0.01 cN/dtex. For PA 6.6, the pre-tension is 0.05 cN/dtex.

The tensile strength of the steel filaments is determined according to ASTM D2969.

Surprisingly, it has been found that the targeted combination of the reinforcement layers mentioned with high-strength reinforcement members provides a tire that, despite the comparatively thin reinforcement layers of the various components (carcass, belt bandage and belt), still has sufficient robustness against special stresses, such as improper use. What is important here is that the reinforcement members of the at least one bandage layer and the at least one carcass layer as well as the at least one belt layer, due to the high-strength design of the raw yarns or steel filaments as well as the shrinkage behavior of the raw yarns made of PA 6.6 cords adapted to the requirements of the bandage layer and the shrinkage behavior of the raw yarns made of PET cords adapted to the requirements of the carcass layer, still enable the tire to be sufficiently robust against special stresses, such as improper use, even when the individual reinforcement members are comparatively low in fineness. This applies in particular to the particularly stressed head region, in which the components mentioned are arranged to overlap one another in the radial direction. In particular, the reinforcement layers mentioned can be arranged to overlap one another in the radial direction.

The high-strength design of the reinforcements of the bandage layer, the carcass layer and the belt layer enables the comparatively thin combination of reinforcement layers to improve rolling resistance while at the same time ensuring sufficient robustness.

The reinforcement layers of the components can therefore be made comparatively thin, which means that a further reduced rolling resistance of the pneumatic vehicle tire can be achieved. At the same time, the reinforcement layers still meet the special requirements of the respective components of the pneumatic vehicle tire: carcass, belt or belt bandage, and their combination enables a tire with sufficient robustness to withstand special stresses such as improper use of the pneumatic vehicle tire.

It has been shown that the pneumatic vehicle tire according to the invention still has sufficient robustness against special stresses, such as improper use, while still having further improved rolling resistance.

An advantageous embodiment is provided by the fact that the raw yarn made of PA 6.6 has a fineness-related strength which, at an elongation of 4%, is in a range of 13.5 cN/tex to 16.0 cN/tex.

The textile reinforcements of the bandage layer thus have a comparatively high modulus of elasticity for PA 6.6 at an elongation of 4% and at the same time an advantageous fatigue resistance in terms of pressure and bending fatigue. This means that the elongation required for tire production is still maintained up to approx. 3%, while higher forces must be applied at higher elongations, which is advantageous for high-speed operation of the tire.

An advantageous embodiment is provided in that the textile strength members of the bandage layer are designed as first bandage strength members, wherein the first bandage strength members are each formed from exactly one of the multifilament yarns made of PA 6.6. The first bandage strength members have a fineness-related strength which, at an elongation of 4%, is in a range from 20.5 cN/tex to 28.0 cN/tex, and a twist factor α' of the twist of the multifilament yarn made of PA 6.6 of 30 to 40.

Despite the fact that the bandage layer can be made particularly thin, the durability and robustness of the tire are sufficiently guaranteed. The pneumatic vehicle tire designed in this way is lightweight and has advantageous rolling resistance.

The twist factor α' of the twist of a multifilament yarn is defined as (twist of the multifilament yarn [t/m]) · (fineness of the multifilament yarn [tex]/ 1000) ^1/2 . The twist factor α' is a measure of the twist per meter of the multifilament yarn, related to the total fineness of the multifilament yarn.

It is advantageous if the twist factor α' of the multifilament yarn made of PA 6.6 of the first bandage strength member is in a range of 25 to 40. This twist factor α' represents an advantageous compromise in terms of fatigue resistance and strength. A lower twist factor α' would be disadvantageous in terms of fatigue resistance, a higher twist factor would mean a lower strength of the textile strength member.

The first bandage strength carrier is made from exactly one of the multifilament yarns made of PA 6.6 and thus has the construction PA 6.6 x1. It is useful if the multifilament yarn made of PA 6.6 has a fineness of 700 dtex.

An advantageous embodiment is provided in that the textile strength members of the bandage layer are designed as second bandage strength members, wherein the second bandage strength members are each designed as cord of the PA 6.6 x 2 construction. The second bandage strength members have a fineness-related maximum tensile force of more than 74 cN/tex, a fineness-related strength which, at an elongation of 4%, is in a range from 12 cN/tex to 20 cN/tex, a hot shrinkage of 4.0% to 7.0%, determined at 180 °C under a pre-tension of 0.05 cN/dtex with an exposure time of two minutes, and a twist factor α of the final twist of the cord of 100 to 250.

The use of such high-strength reinforcements enables comparatively thin reinforcement layers. Such a tire is characterized by low weight and thus advantageous rolling resistance while at the same time being sufficiently durable and robust.

The twist factor α of the end twist of a cord is defined as (twist of the end twist [t/m]) · (fineness of the cord [tex]/ 1000) ^1/2 . The twist factor α is a measure of the twist per meter of the cord, related to the total fineness of the cord.

It is advantageous if the twist factor α of the end twist of this cord of construction PA 6.6 x2 of the second bandage strength member is in a range of 100 to 250. This twist factor represents an advantageous compromise in terms of fatigue resistance and strength. A lower twist factor would be disadvantageous in terms of fatigue resistance, a higher twist factor would mean a lower strength of the cord.

The second bandage strength carrier is designed as a cord of the PA 6.6 x2 construction and is therefore made of exactly two of the multifilament yarns made of PA 6.6, which are twisted together to form the cord. It is useful if the two multifilament yarns made of PA 6.6 each have a fineness of 470 dtex or 700 dtex.

An advantageous embodiment is provided in that the raw yarn made of PET has a fineness-related strength which, at an elongation of 4%, lies in a range of 25 cN/tex to 37 cN/tex.

The use of such a high-strength material for the reinforcement of the carcass enables a tire with advantageous rolling resistance and at the same time sufficient robustness.

An advantageous embodiment is provided in that the textile reinforcements of the carcass ply are designed as first carcass reinforcements, wherein the first carcass reinforcements are each designed as cord of the PET x 2 construction. The first carcass reinforcements have a fineness-related maximum tensile strength of more than 68 cN/tex, a fineness-related tensile strength of activity which, at an elongation of 4%, is in a range of 15 cN/tex to 25 cN/tex according to ASTM D885, a hot shrinkage of less than 2.8%, preferably less than 2.5%, determined at 180 °C under a pretension of 0.01 cN/dtex with an exposure time of 2 minutes and a twist factor α of the final twist of the cord of 150 to 250.

The first carcass reinforcements are characterized by their high-strength properties and at the same time advantageous shrinkage behavior. Such a tire is characterized by a low weight and thus an advantageous rolling resistance while at the same time being sufficiently durable and robust.

The first carcass strength member is designed as a cord of the PET x2 construction and is thus made of exactly two of the multifilament yarns made of PET, which are twisted together to form the cord. It is useful if the two multifilament yarns made of PET each have a fineness of 1100 dtex.

It is advantageous if the twist factor α of the final twist of this cord of construction PET x 2 is in a range of 150 to 250. This twist factor represents an advantageous compromise in terms of fatigue resistance and strength. A lower twist factor would be disadvantageous in terms of fatigue resistance, a higher twist factor would mean a lower strength of the cord.

It is expedient if the textile reinforcements of the bandage layer are designed as first bandage reinforcements of the PA 6.6 x 1 construction and the textile reinforcements of the carcass layer are designed as first carcass reinforcements of the PET x 2 construction.

However, it is also expedient if the textile reinforcements of the bandage layer are designed as second bandage reinforcements of the PA 6.6 x 2 construction and the textile reinforcements of the carcass layer are designed as first carcass reinforcements of the PET x 2 construction.

An advantageous embodiment is provided in that the multifilament yarn made of PA 6.6 has a fineness of 450 dtex to 750 dtex, preferably 470 dtex to 700 dtex. Such a fineness of the multifilament yarn made of PA 6.6 has proven particularly useful for use in the tire according to the invention.

An advantageous embodiment is provided in that the multifilament yarn made of PET has a fineness of 1000 dtex to 1200 dtex, preferably 1100 dtex. Such a fineness of the multifilament yarn made of PET has proven particularly useful for use in the tire according to the invention.

An advantageous embodiment is provided in that the steel filaments of the strength members of the belt layer have a diameter of 0.20 mm to 0.42 mm, preferably from 0.20 mm to 0.32 mm or from 0.33 mm to 0.40 mm. A diameter of 0.20 mm to 0.42 mm has proven particularly suitable for use in the tire according to the invention.

For a strength member of the belt layer formed from exactly one steel filament, a diameter of 0.33 mm to 0.42 mm, preferably 0.35 mm to 0.40 mm, has proven to be particularly suitable.

For a strength member of the belt layer formed from two or more of the steel filaments, a diameter of 0.20 mm to 0.35 mm, preferably from 0.20 mm to 0.32 mm, particularly preferably from 0.20 mm to 0.30 mm, has proven to be particularly suitable.

An advantageous embodiment is provided in that the strength members of the belt layer are designed as first belt strength members, each of which is formed from exactly one of the steel filaments. The steel filaments each have a tensile strength of 3400 N/mm^2 to 4100 N/mm^2 and the belt layer has a strength of in particular 30 kN/dm to 50 kN/dm.

Such a tire is characterized by its low weight and thus advantageous rolling resistance while at the same time being sufficiently durable and robust.

The steel filament preferably has a diameter of 0.33 mm to 0.42 mm, particularly preferably 0.33 mm, 0.35 mm or 0.40 mm.

Another advantageous embodiment is provided in that the strength members of the belt layer are designed as second belt strength members. The second belt strength members are formed from two or three or more steel filaments of the steel filaments. The second belt strength members preferably have the construction x2 or 1+2 or 1+3, particularly preferably the construction x2 or 1+2. The steel filaments each have a tensile strength of 3000 N/mm^2 to 4000 N/mm^2. The belt layer preferably has a strength of 30 kN/dm to 75 kN/dm.

Such a tire is characterized by a low weight and thus an advantageous rolling resistance while at the same time being sufficiently durable and robust.

Preferably, the diameter of the steel filaments of the second belt strength members is 0.20 mm to 0.35 mm, particularly preferably from 0.20 mm to 0.32 mm, particularly preferably from 0.20 mm to 0.30 mm. It is expedient if the strength members of construction 1+2 have a diameter of the steel filaments of 0.29 mm.

An advantageous embodiment is provided in that the PET and/or the PA 6.6 is formed entirely or partially from the respective bio-based polymer.

It is advantageous if the PET is made entirely or partially from bio-based PET.

It is advantageous if the PA 6.6 is made entirely or partially from bio-based PA 6.6.

In the context of the present invention, the term “bio-based polymer” means a polymer which is composed entirely or at least partially of monomers whose starting monomers were obtained directly from biomass.

The polymer can be made entirely from monomers from biomass, i.e. within the scope of the invention, 100% by weight of the starting monomers were obtained directly from biomass. As a result, the pneumatic vehicle tire according to the invention is optimized particularly in terms of sustainability while at the same time having very good properties.

However, the polymer can also be produced only partially from monomers from biomass, especially if some of the monomers on which the polymer is based are not accessible via biomass. In the context of the present invention, "at least partially produced from biomass" means that more than 0% by weight of the starting monomers were obtained directly from biomass. As a result, the pneumatic vehicle tire according to the invention is optimized with regard to the flexibility and sustainability required depending on the availability of starting materials, while at the same time having very good properties.

As is known to those skilled in the art, the proportion of bio-based materials, i.e. the proportion of renewable raw materials in the polymer, can be determined according to ASTM D 6866 (C-14 method).

The PA 6.6 and/or the PET can also be made from non-bio-based PA 6.6 and/or non-bio-based PET, i.e. within the scope of the invention, none of the starting monomers of the respective polymer were obtained directly from biomass. It can be conventional, in particular petroleum-based, PA 6.6 and/or conventional, in particular petroleum-based, PET.

An advantageous embodiment is provided in that the PET and/or the PA 6.6 is formed entirely or partially from the respective recycled polymer.

It is advantageous if the PET is made entirely or partially from recycled PET.

It is advantageous if the PA 6.6 is made entirely or partially from recycled PA 6.6.

In the context of the present invention, the term "recycled polymer" means a polymer which has been obtained by at least one recycling process. The recycling process can be any recycling process known to the person skilled in the art, such as in particular chemical and/or mechanical recycling.

The raw materials used for recycling are mainly bottles, clothing and yarn waste.

In the context of the present invention, mechanical recycling processes also include temperature treatments, such as remelting.

In the context of the present invention, chemical recycling is any type of chemical processing of waste and subsequent recovery of products or raw materials from it. This can also mean complete chemical degeneration into molecules in which the material source, i.e. the chemical nature of the waste, is no longer immediately recognizable, and a subsequent synthesis from these molecules to polymers, which are then used as recycled polymers in the respective multifilament yarn.

Furthermore, industrial yarn waste can also be recycled and used as material for textile reinforcement, as is particularly the case with PET and PA 6.6. Depending on the type and similarity of the yarn waste to the required materials, chemical and/or mechanical recycling is advisable.

Recycled PET, which is produced in particular by mechanical recycling of bottles, differs from original (virgin) PET by additives, such as the content of isophthalic acid (IPA). These additives, particularly IPA, are contained, for example, in PET bottles in particular. Recycled PET obtained from yarn waste through mechanical recycling also has a higher polydispersity index compared to reference yarns that have not been recycled.
The PA 6.6 and/or the PET may be formed entirely or partially from virgin PA 6.6 and/or virgin PET.

In order to ensure reliable adhesion of the textile reinforcements to the rubber, it is advisable to provide the textile reinforcements with an adhesive impregnation, e.g. with a dip in a 1- or 2-bath process. The dip can be a state-of-the-art RFL dip (resorcinol-formaldehyde latex) or an environmentally and health-friendly RFL-free alternative, such as in DE 102014211362 A1 , WO 2019015792 A1 , EP 3702521 A1 , EP 3702522 A1 or EP 3702523 A1 described, act.

The carcass of the pneumatic vehicle tire has one or more carcass layers according to the invention. A particularly simple carcass is obtained when all reinforcing layers of the carcass are designed as a carcass layer according to the invention. The carcass is preferably single-layered and formed by exactly one carcass layer according to the invention.

The belt bandage of the pneumatic vehicle tire has one or more bandage layers according to the invention. A particularly simple belt bandage is provided if all reinforcing layers of the belt bandage are designed as bandage layers according to the invention. The belt bandage is preferably single-layered and formed by exactly one bandage layer according to the invention.

The belt of the pneumatic vehicle tire has one, two or more belt layers according to the invention. The belt preferably has two belt layers designed according to the invention, the strength members of which are arranged so as to cross at an angle and with stiffening in the opposite direction to the circumferential direction. A particularly simple belt is provided if all the reinforcing layers of the belt are designed as belt layers according to the invention.

The manufacture of the pneumatic vehicle tire is carried out in particular in a manner known to the person skilled in the art using devices known to the person skilled in the art.

In particular, an unvulcanized blank of an unvulcanized vehicle tire having the reinforcing layers according to the invention, including all of the described embodiments, is first provided by placing the corresponding components, which comprise unvulcanized rubber mixtures, on top of one another. The blank is then vulcanized.

The pneumatic vehicle tire according to the invention is preferably a tire for a passenger car or a van or a light truck. It is preferably a tire of radial design.

The invention encompasses all advantageous embodiments which are reflected, among other things, in the patent claims. In particular, the invention also encompasses embodiments which result from the combination of different features with different degrees of preference for these features, so that a combination of a first feature designated as "preferred" with another feature designated as "particularly preferred", for example, is also covered by the invention.

In the following, the invention is explained in more detail using two embodiments according to the invention, without, however, being limited to these.

The two pneumatic vehicle tires designed according to the invention, in particular of a radial design, have a carcass formed from a carcass ply, a belt arranged radially outside the carcass and formed from two belt layers, and a belt bandage resting on the belt from the radial outside and formed by at least one bandage layer, which covers at least the belt edges. The carcass ply, the belt layers and the bandage layer each have reinforcements which are embedded in rubber material within the respective layer, arranged parallel and spaced from one another, wherein the reinforcements of the bandage layer are textile reinforcements, each formed from at least one multifilament yarn made of polyamide 6.6 (PA 6.6), wherein the reinforcements of the carcass ply are textile reinforcements, each formed from at least one multifilament yarn made of polyethylene terephthalate (PET), and wherein the reinforcements of the belt layers are each formed from at least one steel filament. The reinforcements of the two belt layers are arranged so as to cross at an angle and with stiffening in the opposite direction to the circumferential direction.

• Erster Fahrzeugluftreifen: PA6.6 700x1, PET 1100x2, Stahl 1x0,35
• Zweiter Fahrzeugluftreifen: PA6.6 470x2, PET1100x2, Stahl 1+2x0,29

The two pneumatic vehicle tires according to the invention have the following strength members in their reinforcement layers (in the order bandage layer, carcass layer, belt layer):

• First pneumatic vehicle tire: PA6.6 700x1, PET 1100x2, steel 1x0.35
• Second vehicle pneumatic tire: PA6.6 470x2, PET1100x2, steel 1+2x0.29

The textile reinforcements of the bandage layer of the two pneumatic vehicle tires are characterized by the fact that the multifilament yarn made of PA 6.6 has a fineness of 100 dtex to 1500 dtex, that the raw yarn made of PA 6.6 of the multifilament yarn made of PA 6.6 has a fineness-related maximum tensile force of greater than 87 cN/tex, determined according to ASTM D885, and a hot shrinkage of greater than 6%, determined at 180°C under a pre-tension of 0.05 cN/dtex with an exposure time of two minutes.
Furthermore, the raw yarn made of PA 6.6 has a fineness-related strength which, at an elongation of 4%, is in a range of 13.5 cN/tex to 16.0 cN/tex.

The textile reinforcements of the carcass ply of the two pneumatic vehicle tires are characterized by the fact that the multifilament yarn made of PET has a fineness of 1100 dtex, that the raw yarn made of PET of the multifilament yarn made of PET has a fineness-related maximum tensile strength of 83.5 cN/tex, determined according to ASTM D885, and a heat shrinkage of 7.2%, determined at 180 °C under a pre-tension of 0.01 cN/dtex with an exposure time of two minutes. Furthermore, the raw yarn made of PET has a fineness-related strength, at an elongation of 4%, of 32.1 cN/tex.

Furthermore, the textile reinforcements of the carcass ply of the two pneumatic vehicle tires designed according to the invention are each designed as first carcass reinforcements, with the first carcass reinforcements being designed as cord of the PET x 2 construction, with the multifilament yarns made of PET having a fineness of 1100 dtex. The first carcass reinforcements have a fineness-related maximum tensile force of 70.9 cN/tex, a fineness-related strength which is 20.1 cN/tex according to ASTM D885 at an elongation of 4%, a hot shrinkage of 2.2%, determined at 180 °C under a pre-tension of 0.01 cN/dtex with an exposure time of 2 minutes and a twist factor α of the final twist of the cord of 195.

The strength members of the belt layers of the two pneumatic vehicle tires are characterized by the fact that the steel filament has a tensile strength of 3000 N/mm^2 to 4100 N/mm^2, determined according to ASTM D2969, and a carbon content of 0.79 wt.% to 1.10 wt.%.

The first pneumatic vehicle tire according to the invention, in particular of radial design, is characterized with regard to the bandage layer in that the textile reinforcements of the bandage layer according to the invention are designed as first bandage reinforcements, wherein the first bandage reinforcements are each made of exactly one of the multifilament yarns made of PA 6.6. The multifilament yarn made of PA 6.6 has a fineness of 700 dtex. Furthermore, the first bandage reinforcements have a fineness-related strength which, at an elongation of 4%, is in a range of 20.5 cN/tex to 28.0 cN/tex, and a twist factor α' of the twist of the multifilament yarn made of PA 6.6 of 25 to 40.

The first pneumatic vehicle tire according to the invention is characterized with regard to the belt layers in that the strength members of the belt layers are each formed from exactly one of the steel filaments and that the steel filament has a diameter of 0.35 mm and a tensile strength of 3742 N/mm^2 and that the belt layer has a strength of 34 kN/dm.

The second pneumatic vehicle tire according to the invention is characterized with regard to the bandage layer in that the reinforcements of the bandage layer according to the invention are designed as second bandage reinforcements. They have the construction PA 6.6 x2, whereby the multifilament yarns made of PA 6.6 have a fineness of 470 dtex. The second bandage reinforcements have a fineness-related maximum tensile force of more than 74 cN/tex, a fineness-related strength which is 12 cN/tex to 20 cN/tex at an elongation of 4%, a hot shrinkage of 4.0% to 7.0%, determined at 180 °C under a pre-tension of 0.05 cN/dtex with an exposure time of two minutes, and a twist factor α of the end twist of the cord of 100 to 250.

The second pneumatic vehicle tire according to the invention is characterized with regard to the belt layers in that the strength members of the belt layers are each formed from three of the steel filaments and have the construction 1 + 2. The steel filaments have a diameter of 0.29 mm and a tensile strength of 3593 N/mm^2. The belt layer has a strength of 64 kN/dm.

It has been shown that the two pneumatic vehicle tires designed according to the invention still have sufficient robustness against special stresses despite the comparatively low use of materials due to the combination of high-strength materials in the reinforcing layers of the carcass, the belt bandage and the belt. At the same time, the rolling resistance is further improved due to the comparatively low use of materials.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was 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 accepts no liability for any errors or omissions.

Cited patent literature

• EP 3254870 A1 [0011]
• EP 3254871 A1 [0011]
• EP 3493999 A1 [0012]
• EP 3544826 A1 [0013]
• DE 102019218723 A1 [0013]
• DE 102014211362 A1 [0077]
• WO 2019015792 A1 [0077]
• EP 3702521 A1 [0077]
• EP 3702522 A1 [0077]
• EP 3702523 A1 [0077]

Claims (12)

Pneumatic vehicle tire, comprising a carcass having a carcass ply, a belt arranged radially outside the carcass and having a belt layer, and a belt bandage resting radially on the outside of the belt and having a bandage layer, wherein the carcass ply, the belt layer and the bandage layer each have reinforcements which are embedded in rubber material within the respective layer, arranged parallel and spaced from one another, • wherein the reinforcements of the bandage layer are textile reinforcements, each formed from at least one multifilament yarn made of polyamide 6.6 (PA 6.6), • wherein the reinforcements of the carcass ply are textile reinforcements, each formed from at least one multifilament yarn made of polyethylene terephthalate (PET), and • wherein the reinforcements of the belt layer are each formed from at least one steel filament, characterized in that the multifilament yarn made of PA 6.6 has a fineness of 100 dtex to 1500 dtex, that the raw yarn made of PA 6.6 of the Multifilament yarn made of PA 6.6 • has a fineness-related maximum tensile strength of greater than 87 cN/tex, determined in accordance with ASTM D885, and • a heat shrinkage of greater than 6%, determined at 180°C under a pre-tension of 0.05 cN/dtex and an exposure time of two minutes, that the multifilament yarn made of PET has a fineness of 50 dtex to 2500 dtex, that the raw yarn made of PET of the multifilament yarn made of PET • has a fineness-related maximum tensile strength of ≥ 70 cN/tex, determined in accordance with ASTM D885, and • a heat shrinkage of less than 8%, determined at 180 °C under a pre-tension of 0.01 cN/dtex and an exposure time of two minutes, and that the steel filament • has a tensile strength of 3000 N/mm^2 to 4100 N/mm^2, determined in accordance with ASTM D2969, and • a carbon content of 0.79 wt.% to 1.10 wt.%. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the raw yarn made of PA 6.6 has a fineness-related strength which, at an elongation of 4%, is in a range from 13.5 cN/tex to 16.0 cN/tex. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the textile strength members of the bandage layer are designed as first bandage strength members, wherein the first bandage strength members are each formed from exactly one multifilament yarn made of PA 6.6 of the at least one multifilament yarn made of PA 6.6 and that the first bandage strength members • have a fineness-related strength which, at an elongation of 4%, is in a range from 20.5 cN/tex to 28.0 cN/tex, and • a twist factor α' of the twist of the multifilament yarn made of PA 6.6 of 25 to 40. Pneumatic vehicle tires according to at least one of the Claims 1 until 2 , characterized in that the textile strength members of the bandage layer are designed as second bandage strength members, wherein the second bandage strength members are each designed as cord of construction PA 6.6 x 2 and have • a fineness-related maximum tensile force of more than 74 cN/tex, • a fineness-related strength which, at an elongation of 4%, is in a range from 12 cN/tex to 20 cN/tex, • a hot shrinkage of 4.0% to 7.0%, determined at 180 °C under a pre-tension of 0.05 cN/dtex with an exposure time of two minutes, and • a twist factor α of the final twist of the cord of 100 to 250. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the raw yarn made of PET has a fineness-related strength which, at an elongation of 4%, is in a range from 25 cN/tex to 37 cN/tex. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the textile strength members of the carcass ply are designed as first carcass strength members, wherein the first carcass strength members are each designed as cord of the PET x 2 construction and • have a fineness-related maximum tensile force of more than 68 cN/tex, • have a fineness-related strength which, at an elongation of 4%, is in a range from 15 cN/tex to 25 cN/tex according to ASTM D885, • have a hot shrinkage of less than 2.8%, preferably less than 2.5%, determined at 180 °C under a prestress of 0.01 cN/dtex with an exposure time of 2 minutes and • have a twist factor α of the final twist of the cord of 150 to 250. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that • the multifilament yarn made of PA 6.6 has a fineness of 450 dtex to 750 dtex, preferably 470 dtex to 700 dtex, and/or • the multifilament yarn made of PET has a fineness from 1000 dtex to 1200 dtex, preferably from 1100 dtex. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the steel filament has a diameter of 0.20 mm to 0.42 mm, preferably from 0.20 mm to 0.32 mm or from 0.33 mm to 0.42 mm. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the strength members of the belt layer are designed as first belt strength members, that the first belt strength members are each formed from exactly one of the steel filaments, that the steel filaments each have a tensile strength of 3400 N/mm^2 to 4100 N/mm^2 and that the belt layer has a strength of in particular 30 kN/dm to 50 kN/dm. Pneumatic vehicle tires according to at least one of the Claims 1 until 8 , characterized in that the strength members of the belt layer are designed as second belt strength members, that the second belt strength members are each formed from two or three or more steel filaments of the steel filaments, preferably forming the construction x2 or 1+2 or 1+3, particularly preferably forming the construction x2 or 1+2, that the steel filaments have a tensile strength of 3000 N/mm^2 to 4000 N/mm^2 and that the belt layer has a strength of in particular 30 kN/dm to 75 kN/dm. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the PET and/or the PA 6.6 is formed entirely or partially from the respective bio-based polymer. Pneumatic vehicle tire according to at least one of the preceding claims, characterized in that the PET and/or the PA 6.6 is formed entirely or partially from the respective recycled polymer.