阅读说明：本技术 车辆轮胎 (Vehicle tyre ) 是由 法比安·彼得斯 迪特尔·赫罗米 马蒂亚斯·普吕克斯 塞巴斯蒂安·芬格 于 2019-07-29 设计创作，主要内容包括：本发明涉及一种车辆充气轮胎,其具有由硫交联的橡胶混合物构成的内衬,该硫交联的橡胶混合物含有80至100phr(重量份,基于100重量份的该混合物中的所有橡胶)的至少一种丁基橡胶和/或卤化丁基橡胶、至少一种填充剂、1至60phr的至少一种香豆酮-茚树脂以及1至60phr的至少一种脂族烃树脂,其中香豆酮-茚树脂和脂族烃树脂的总质量不超过65phr。(The invention relates to a pneumatic vehicle tire having an inner liner composed of a sulfur-crosslinked rubber mixture containing 80 to 100phr (parts by weight, based on 100 parts by weight of all the rubbers in the mixture) of at least one butyl rubber and/or halogenated butyl rubber, at least one filler, 1 to 60phr of at least one coumarone-indene resin and 1 to 60phr of at least one aliphatic hydrocarbon resin, wherein the total mass of coumarone-indene resin and aliphatic hydrocarbon resin does not exceed 65 phr.)

1. A pneumatic vehicle tire having an innerliner composed of a sulfur-crosslinked rubber compound containing

80 to 100phr (parts by weight, based on 100 parts by weight of all the rubbers in the mixture) of at least one butyl rubber and/or halogenated butyl rubber,

-at least one filler,

-1 to 60phr of at least one coumarone-indene resin and

-from 1 to 60phr of at least one aliphatic hydrocarbon resin,

wherein the total mass of coumarone-indene resin and aliphatic hydrocarbon resin does not exceed 65 phr.

2. A pneumatic tyre for vehicles as claimed in claim 1, characterized in that the rubber mixture of the inner liner contains 80 to 100phr of at least one halogenated butyl rubber.

3. A pneumatic tyre for vehicles as claimed in claim 1 or 2, characterized in that the rubber mixture of the inner liner contains up to 20phr of at least one further diene rubber selected from the group consisting of: polyisoprene, polybutadiene, styrene-butadiene copolymers, and epoxidized natural rubber.

4. Pneumatic tire for vehicles according to at least one of claims 1 to 3, characterized in that the rubber mixture of the inner liner contains 5 to 30phr of at least one coumarone-indene resin.

5. Pneumatic vehicle tyre according to at least one of the preceding claims, characterized in that the rubber mixture of the inner liner contains 5 to 30phr of at least one aliphatic hydrocarbon resin.

6. Pneumatic vehicle tyre according to at least one of the preceding claims, characterized in that the rubber mixture of the inner liner is free of plasticizer oil and processing aids, in particular mineral oil plasticizers.

Technical Field

The present invention relates to a pneumatic vehicle tire having an inner liner composed of a sulfur-crosslinked rubber compound.

Background

In a tubeless vehicle pneumatic tire, a minimum air permeability inner liner arranged radially on the inside ensures that air pumped into the tire does not escape. It is necessary to prevent the escape of air, since the escape results in a low pressure in the tyre, which considerably impairs the service life of the tyre. Moreover, the innerliner protects the carcass from inward diffusion of air and moisture, which may damage the carcass and/or the strength members of the belt. In order for the innerliner to remain airtight, it must also have good resistance to cracking and fatigue so as not to develop cracks during driving operations that affect the airtightness.

The rubber used for the innerliner is typically butyl, chlorobutyl or bromobutyl rubber, sometimes blended with other diene rubbers. Butyl rubber and halobutyl rubber have low gas permeability. The reason for blending butyl rubber and halobutyl rubber with a rubber selected from the group consisting of polybutadiene, styrene-butadiene copolymers, 3, 4-polyisoprene, cis-1, 4-polyisoprene, natural rubber, epoxidized natural rubber, styrene-isoprene copolymers and styrene-isoprene-butadiene copolymers is to increase the viscosity of the formulation, reduce costs, and improve mechanical properties.

The inclusion of bulky fillers with low or zero activity may further increase the air impermeability of the butyl rubber or halobutyl rubber based mixtures. These fillers include, for example, kaolin, N660 carbon black and chalk. However, since the innerliner should have a low modulus of elasticity and low hardness in order to prevent cracking under dynamic stress, but this is not consistent with a high proportion of inactive filler, mineral oil plasticizers are usually added to the rubber mixture, which reduces the modulus of elasticity and hardness of the mixture, but at the same time increases the gas permeability, resulting in a narrow optimum range for the amounts of mineral oil plasticizer and filler used.

Resins are known substitutes or additives for mineral oil plasticizers in rubber mixtures for the inner liners of pneumatic tires for vehicles.

WO 2010/024955A 1 discloses rubber mixtures for the inner liner of pneumatic tyres for vehicles, comprising aromatic hydrocarbon resins having a softening point between 75 ℃ and 120 ℃, such as40MS (bitumen), and aliphatic hydrocarbon resins having simultaneously a glass transition temperature above 40 ℃ and a softening point below 140 ℃, such as Escorez^TM 1102。

EP 2957592 a1 discloses rubber mixtures for vehicle pneumatic tire innerliners which contain esters of aliphatic dibasic acids and resins having a softening point above 60 ℃ for good air impermeability (gastightness) together with good resistance to cracking at low temperatures. Also proposed as resins are combinations of different resins, including the use of "hybrid resins". In this case, these mixed resins are resin mixtures in which a monomer of an aromatic structure and a monomer of an aliphatic structure are polymerized.40MS is described as such a hybrid resin and is used in combination with other aliphatic resins.

Disclosure of Invention

An object of the present invention is to provide a pneumatic tire for vehicles in which a rubber mixture for an inner liner is further improved in processability, hardness, resilience at 70 ℃ and airtightness.

This object is achieved in that the rubber mixture for the inner liner contains

80 to 100phr (parts by weight, based on 100 parts by weight of all the rubbers in the mixture) of at least one butyl rubber and/or halogenated butyl rubber,

-at least one filler,

-1 to 60phr of at least one coumarone-indene resin and

-from 1 to 60phr of at least one aliphatic hydrocarbon resin,

wherein the total mass of coumarone-indene resin and aliphatic hydrocarbon resin does not exceed 65 phr.

It has been surprisingly found that in rubber mixtures based on butyl rubber and/or halogenated butyl rubber, a specific combination of coumarone-indene resin with an aliphatic hydrocarbon resin makes it possible to achieve particularly good processability combined with high impermeability to air and suitable hardness and resilience at 70 ℃. The reason for this may be that this particular resin combination creates an optimal transition between the filler and the rubbery polymer. Furthermore, the rubber mixtures have advantageous vulcanization characteristics. They have an increased coking time (t)₁₀) And reduced cure time (t) to 40% crosslinking₄₀) And thus provides process reliability along with more economical production. Pneumatic vehicle tires having an inner liner composed of such a rubber mixture are distinguished by good productivity and a high service life. Due to the reduced gas permeability, the components in the tire adjacent to the innerliner are exposed to lower oxidative stress and aging, and the tire pressure drops much more slowly. The thickness of the liner may be reduced.

The unit "phr" (parts per hundred parts of rubber by weight) used in this document is the standard unit for the amount of mixture formulation in the rubber industry. The dosage of parts by weight of these individual substances is always based here on 100 parts by weight of the total mass of all rubbers present in the mixture.

The rubber mixtures for the inner liners contain 80 to 100phr of at least one butyl rubber and/or halogenated butyl rubber, wherein these rubbers can be used in the form of freshly produced rubbers or in the form of recyclates.

In order to reduce the gas permeability, the rubber mixture preferably contains 80 to 100phr of at least one halogenated butyl rubber. This may be chlorobutyl rubber and/or bromobutyl rubber.

The rubber mixture for the inner liner and the butyl rubber and/or halobutyl rubber also contain up to 20phr of at least one additional diene rubber selected from the group consisting of: polyisoprene, polybutadiene, styrene-butadiene copolymers, and epoxidized natural rubber. The diene rubber may be functionalized at the chain ends and/or along the polymer chain and/or at the coupling center with at least one group chosen from: an epoxy group containing an alkoxysilyl group, a hydroxyl group, a carboxyl group, a silane sulfide group, a siloxane group, a silicone group, a phthalocyanine group, and an amino group.

As fillers, the rubber mixtures for the inner liner may use all fillers known to the person skilled in the art for such mixtures. These fillers include low-or zero-active, bulky fillers such as certain types of carbon black, kaolin or chalk. Additional fillers present in the rubber mixture may be, for example, silica, aluminum oxide, calcium carbonate, calcium hydroxide, sheet silicates, talc, graphite, magnesium oxide, magnesium hydroxide, and zeolites in any combination.

The rubber mixtures for the inner liners contain from 1 to 60phr, preferably from 5 to 30phr, of at least one coumarone-indene resin. Such resins are obtained in the polymerization of unsaturated compounds present in light oils from bituminous coal tar, such as indene and coumarone (benzofuran).

Furthermore, the rubber mixture for the inner liner contains 1 to 60phr, preferably 5 to 30phr, of at least one aliphatic hydrocarbon resin. Here, the aliphatic hydrocarbon resin is a resin obtained by polymerizing a monomer containing a C5 and/or C6 olefin. These monomers are obtained, for example, in the cracking of mineral oils.

The rubber mixtures used for the inner liner may contain, in addition to the substances mentioned, customary rubber blends in customary amounts. These include, for example, plasticizers, especially mineral oil plasticizers, aging stabilizers, activators such as zinc oxide and fatty acids (e.g., stearic acid), waxes and masticating aids.

In an advantageous development of the invention, the rubber mixtures for the inner liner are free of plasticizer oil and processing aids, in particular free of mineral oil plasticizers. It has been found that the resin combination according to the invention can replace plasticizer oils, such as mineral oil plasticizers which are generally considered to be of environmental concern, without having to accept a loss of other desirable properties of the liner.

The rubber mixture for the inner liner has been crosslinked in the presence of sulfur and/or a sulfur donor; for this purpose, vulcanization accelerators are usually added to the starting mixture. The vulcanization accelerator may here be selected from the group consisting of: thiazole accelerators, mercapto accelerators, sulfenamide accelerators, thiocarbamate accelerators, thiuram accelerators, thiophosphate accelerators, thiourea accelerators, xanthate accelerators and guanidine accelerators. The sulfur and/or sulfur donors and vulcanization accelerators are used in customary amounts.

The rubber mixtures for the inner liner are produced in a conventional manner by: a base mixture is first prepared, usually in one or more mixing stages, which contains all the ingredients except the vulcanization system (sulfur and substances which affect vulcanization), and the final mixture is then produced by adding the vulcanization system. The mixture is then further processed, for example by a calendering operation, and formed into an inner liner. In the production of pneumatic vehicle tires, the calendered innerliner is placed in a conventional manner on a tire building drum and the tire is then completed with additional components to provide a tire blank. This is vulcanized by methods known to those skilled in the art.

Pneumatic vehicle tires are distinguished by simple processability in combination with high impermeability to air and service life.

Detailed Description

The invention will now be elucidated in detail with reference to the comparative and working examples summarized in table 1.

For all mixture examples in the table, the amounts are parts by weight based on 100 parts by weight of total rubber (phr). The comparative mixture is indicated with V and the mixture used in the liner of the present invention is indicated with E. These mixtures differ only in the plasticizer oil and resin blend. Mixture 1(V) is a rubber mixture for inner liner containing plasticizer oil. In mixture 2(V), some of the plasticizer oil has been replaced by an aliphatic hydrocarbon resin. Mixture 3(V) contained only aliphatic hydrocarbon resin and mixture 4(V) contained only coumarone-indene resin. Mixture 5(E) for a pneumatic vehicle tire comprising an innerliner of the invention does not contain any plasticizer oil, but contains a specific combination of coumarone-indene resin and an aliphatic hydrocarbon resin.

The mixture was produced in two stages in a laboratory tangential mixer under standard conditions. Until 10% (t) is reached₁₀) Or 40% (t)₄₀) The conversion time to the crosslinking level of (a) was determined by monitoring the vulcanization process according to DIN 53529 using a rotorless vulcanization machine. The Mooney viscosity (ML 1+4) of the mixture was also determined in accordance with DIN 53523 using a shear disk viscometer at 100 ℃.

All mixtures were used to produce test specimens by vulcanization under pressure at 160 ℃ for 15 minutes and these test specimens were used to determine the material properties typical in the rubber industry. The test samples were tested using the following test methods:

● Shore A hardness at room temperature by durometer in accordance with DIN ISO 7619-1

● resilience at 70 ℃ according to DIN 53512 or ISO 4662 or ASTM D1054

● air permeability according to DIN 53536 at an air temperature of 70 ℃ without aging or with aging at 70 ℃ for 14 days

Tires of size 255/30R 19 were also made, the innerliner of which contained the mixture of table 1, and these tires were used to perform the following tests:

● service life of tire: drum test for crack/fracture resistance of liner and sidewalls according to service life test according to FMVSS 139

● rolling resistance: according to ISO 28580

The determined values were converted to performance and each of the tested tire characteristics of comparative blend V1 was normalized to 100% performance. The tire characteristics of the other mixtures are then related to this mixture V1. A value less than 100% means here that the characteristics are deteriorated, while a value greater than 100% indicates that the characteristics are improved.

TABLE 1

^aAliphatic C5 resin, Piccotac, with narrow molecular weight distribution^TM1095 Istman Chemical Company (Eastman Chemical Company)

^bA coumarone-indene resin,C 90， Rütgers Chemicals

it is evident from Table 1 that the particular combination of two resins in mixture 5(E) allows good processing characteristics (as indicated by Mooney viscosity and low scorch time (t)₁₀/t₄₀) Along with low air permeability. Particularly surprising is the effect of the resin combination on the resilience at 70 ℃, which acts as an indicator of rolling resistance. Low rebound is typically accompanied by low rolling resistance. If the two resins are combined, not a significant reduction in resilience at 70 ℃ as expected from separate measurements according to 3(V) and 4(V) is obtained, but a resilience at 70 ℃ at the level of 3 (V). The tires comprising the mixture 5(E) also have a high tire service life with respect to cracking/fracture resistance of the innerliner and sidewall and low rolling resistance.

At the same time, it is advantageous that the mixture 5(E) for the inner liner can achieve at least as good properties as those with the mixture 1(V), but without the use of plasticizer oils and processing aids, in particular mineral oil plasticizers.