Compounds, rubber blends containing said compounds, vehicle tires containing said rubber blends as at least one component, processes for the manufacture of said compounds, and the use of said compounds as ageing stabilizers and / or antiozonants and / or dyes

Abstract

The present invention relates to a compound, a rubber blend containing said compound, a vehicle tire comprising at least one component of this rubber blend, a process for the preparation of the compound and the use of the compound as an ageing protectant and / or antiozonant and / or dye. 1 xi) aromatic groups, which optionally have a substituent selected from the group consisting of halogen groups, cyano groups, ester groups, ketone groups, ether groups and thioether groups; and xii) linear, branched and cyclic aliphatic C4-C 12 xiii) aromatic and aliphatic C1-C 12 In one embodiment, the aryl group is selected from the group consisting of a aryl group and a aryl group. TIFF2024529394000029.tif47170

Description

[Technical field]

[0001] The present invention relates to a compound, a rubber mixture containing the compound, a vehicle tire comprising the rubber mixture in at least one component, a process for producing the compound, and the use of the compound as ageing stabilizer and / or antiozonant and / or dye. [Background technology]

[0002] Vehicle tires and technical rubber articles are known to employ polymeric materials, particularly rubber.

[0003] In case of long-term storage and especially in the intended use, which is often at high temperatures, natural rubber and synthetic polymers (such as IR, BR, SBR, ESBR, etc.), as well as natural and synthetic oils, fats and lubricants, undergo oxidation reactions that adversely affect their original desired properties. Depending on the type of polymer, the polymer chains shorten until the material liquefies or until subsequent hardening of the material occurs.

[0004] Ageing stabilizers therefore play a crucial role in the durability of vehicle tires and other technical rubber articles.

[0005] Known ageing stabilizers are aromatic amines, such as 6-PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine), IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine) or SPPD (N-(1-phenylethyl)-N'-phenyl-p-phenylenediamine).

[0006] These molecules are capable of reacting with oxygen or ozone or with free radicals that are formed, such as alkyl, alkoxy and alkylperoxy radicals, thereby scavenging them and thus protecting the rubber, etc., from further oxidation reactions.

[0007] However, a drawback of this substance class is that they are suspected of being carcinogenic.

[0008] Aging stabilizers that specifically react with ozone to achieve its scavenging are also called "antiozonants." Summary of the Invention [Problem to be solved by the invention]

[0009] The aim of the present invention is to provide new compounds which can be used in particular as ageing stabilizers for vehicle tyres or other industrial rubber articles, and which in particular have a lower potential hazard, in combination with a sufficient solubility in the respective matrix, for example in particular in polymers, which are intended to prevent the tendency to blooming whilst maintaining an optimal protection against oxygen and ozone, reducing the hazards to health. [Means for solving the problem]

[0010] This object is achieved by the compound according to the invention as claimed in claim 1, by the rubber mixture according to the invention which contains the compound and by the vehicle tyre according to the invention which comprises in at least one of its components a rubber mixture according to the invention.

[0011] This object is further achieved by using the compounds as ageing stabilizers and / or antiozonants.

[0012] The compounds according to claim 1 may further be used as dyes.

[0013] This object is further achieved by the process according to the invention for the preparation of the compounds according to the invention.

[0014] The compound as claimed in claim 1 has the general formula I: [ka] [In the formula, R 1 teeth, xi) aromatic groups, wherein the aromatic groups optionally bear substituents selected from the group consisting of halogen groups, cyano groups, ester groups, ketone groups, ether groups and thioether groups; and xii) linear, branched and cyclic aliphatic C4-C 12 xiii) aromatic and aliphatic C1-C 12 Combination with groups is selected from the group consisting of In the formula, the group R 2 and R 3 are each independently the same or different, and are linear, branched and cyclic, saturated and unsaturated, aliphatic C1-C 12 groups, aryl groups optionally bearing one or more halogen substituents, and halogen groups (wherein fluorine, bromine and chlorine are preferred), cyano groups, ester groups, ketone groups, ether groups and thioether groups, where n has a value of 0 or 1 or 2 or 3 or 4, where when n is 2 or 3 or 4, the group R 3 are, independently of one another, identical or different, where m has a value of 0 or 1 or 2 or 3, and where m is 2 or 3, the group R 2 are, independently of each other, identical or different] has.

[0015] R 1 benzyl and linear, branched and cyclic aliphatic C4-C 12 is selected from the group consisting of In the formula, R 3 Linear, branched and cyclic aliphatic C1-C 12 groups and aryl groups, cyano groups, halogen groups (wherein fluorine, bromine and chlorine are preferred), ether groups and thioether groups, in which n has a value of 0 or 1 or 2 or 3 or 4, and when n is 2 or 3 or 4, the group R 3 are, independently of one another, identical or different, In the formula, R 2 Linear, branched and cyclic aliphatic C1-C 12groups, and aryl groups, cyano groups, halogen groups (wherein fluorine, bromine and chlorine are preferred), ether groups and thioether groups, In the formula, m has a value of 0 or 1 or 2 or 3, and when m is 2 or 3, the group R 3 are, independently of each other, identical or different This is preferable.

[0016] When n is, in each case, 0 (zero), 1, 2, or 3, a hydrogen atom is 3 It will be apparent to one skilled in the art that, instead of m, the structure is bonded to the corresponding carbon atom of the benzene ring. Similarly, when m is 0 or 1 or 2, all remaining free positions in the benzene ring of the structure are hydrogen atoms.

[0017] (R 2 ) m and (R 3 ) n And R 1 It will be equally clear to those skilled in the art that the representation of the HN bond should be understood as meaning that these groups may each be located at any position on the respective benzene ring, except, of course, that two or more may not be at the same position at the same time, as would already be precluded by the tetravalency of the carbon atoms of the benzene ring.

[0018] In the context of the present invention, the class "C4-C 12 The description of "radical" should be understood to mean a radical having 4 to 12 carbon atoms. Independently, "C1" is also used to describe the position of the most highly oxidized carbon atom / highest priority carbon atom according to the Cahn-Ingold-Prelog rules (CIP). What is meant in the respective context will be clear to the skilled person.

[0019] The compounds according to the invention are acridinone derivatives and show a low potential hazard compared to known aging stabilizers based on aniline (possible cleavage products of 6-PPD). Comparison of the safety data sheets of the basic structure aniline and acridinone reveals that, unlike aniline, acridinone is neither genotoxic nor mutagenic. This is a crucial advantage, especially in technical applications such as vehicle tires or other rubber products, where rubber components may be liberated by wear or other decomposition processes.

[0020] The compounds according to the invention also have an improved protective effect against oxidation and thus ageing, in particular with respect to polymers, compared to 6-PPD. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention includes all advantageous embodiments, among others, as reflected in the claims. The present invention also includes embodiments resulting from combinations of different features having different priorities relative to these features, in particular such that the invention also includes combinations of a first feature described as "preferred" or in the context of an advantageous embodiment with a further feature, for example described as "particularly preferred".

[0022] base R 2 and R 3 are each independently the same or different, and are linear, branched and cyclic, saturated and unsaturated, aliphatic C1-C 12 groups, aryl groups optionally bearing one or more halogen substituents, and halogen groups (wherein fluorine, bromine and chlorine are preferred), cyano groups, ester groups, ketone groups, ether groups and thioether groups.

[0023] The enumerated groups R 2 and R 3 may in particular already be attached to the respective benzene ring / precursor thereof by the selection of suitable starting materials.

[0024] It is preferred if n is 0 (zero).

[0025] It is preferred if m is 0 (zero).

[0026] Radical R 1 is, xi) an aromatic radical which may have a substituent selected from the group consisting of a halogen radical, a cyano radical, an ester radical, a ketone radical, an ether radical, and a thioether radical; and xii) linear, branched and cyclic aliphatic C3-C 12 Radicals, especially C4-C 12 radicals, and xiii) aromatic and aliphatic C1-C 12 The radical combination is selected from the group consisting of:

[0027] An aromatic radical from subgroup xi) is, for example, preferably a phenyl radical.

[0028] The aromatic radicals of subgroup xi) may bear substituents.

[0029] As mentioned above, these are selected from the group consisting of halogen radicals, cyano radicals, ester radicals, ketone radicals, ether radicals and thioether radicals.

[0030] It is preferred if the substituents are selected from the group consisting of ester radicals, ketone radicals, ether radicals and thioether radicals.

[0031] In a preferred embodiment, the aromatic radical is unsubstituted at the two carbon atoms adjacent to the C1 atom, i.e., the carbon atom bonded to the N atom. Thus, in the case of a benzene ring as a basic structure, it is preferred that there is no substituent at the ortho position relative to the N atom.

[0032] In a further preferred embodiment the aromatic radicals of subgroup xi) are unsubstituted.

[0033] R 1 is preferably linked to the nitrogen atom (N) via a tertiary carbon atom. Thus, the C1 atom is preferably a tertiary carbon atom.

[0034] In the context of the present invention, the term "tertiary carbon atom" should be understood to mean a carbon atom which is bonded to only one hydrogen atom.

[0035] This, compared to secondary and quaternary carbon atoms, results in a particularly good protective effect due to the presence of the compound in rubber mixtures, especially vehicle tires and other industrial rubber articles, and leads to optimal reactivity, especially in relation to mechanisms related to ageing stabilization, avoiding undesirable side reactions.

[0036] The mixed aromatic and aliphatic radicals of subgroup xiii) are, for example, preferably selected from the group consisting of benzyl and 1-phenylalkyl radicals having a total of 7 to 18 carbon atoms, in particular selected from the benzyl and 1-phenylethyl radicals, the 1-phenylalkyl radicals, in particular the 1-phenylethyl, being particularly preferred for the tertiary carbon atom.

[0037] In a further advantageous embodiment, R 1 is a branched or cyclic alkyl radical having 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms, where R 1 is particularly preferably selected from the 1,3-dimethylbutyl radical and the cyclohexyl radical, where R 1 is very particularly preferably the 1,3-dimethylbutyl radical.

[0038] This achieves particularly good solubility in rubber mixtures for vehicle tires and other industrial rubber articles.

[0039] In a preferred embodiment, the compound has formula II: [ka] It has the structure:

[0040] The compounds of formula II) indeed make it possible to achieve further improvements in protection against oxidation and therefore against aging, especially in polymers, and at the same time, as mentioned above, the compounds of formula II) are significantly less harmful to health than, for example, 6-PPD or other representatives of this substance class.

[0041] Thus, compared to 6-PPD, the compound of formula II) is a better and at the same time less harmful to health and environmentally friendly ageing stabilizer.

[0042] The inventive compounds of formula I), formula II) and all the above mentioned are particularly suitable as ageing stabilizers and / or antiozonants in vehicle tyres and / or technical rubber articles, in particular in air springs, bellows, conveyor belts, belts, drive belts, hoses, rubber bands, profiles, seals, membranes, tactile sensors for medical applications or robotics or shoe soles or parts thereof, and / or oils and / or lubricants.

[0043] The present invention therefore further provides the use of the compounds according to the invention as ageing stabilizers and / or antiozonants in vehicle tyres and / or industrial rubber articles, in particular in air springs, bellows, conveyor belts, belts, drive belts, hoses, rubber bands, profiles, seals, membranes, tactile sensors for medical or robotic applications, or shoe soles or parts thereof, and / or oils and / or lubricants.

[0044] To use the compounds of formula I), formula II), and all of the foregoing in the recited articles or materials, the compounds are used in compositions or are incorporated into the compositions.

[0045] In vehicle tires or other industrial rubber articles, said composition is especially present in a rubber mix.

[0046] The present invention further provides the use of the inventive compounds of formula I), formula II) and all above as dyes in fibres and / or polymers and / or paper and / or (decorative) paints and coatings.

[0047] A further aspect of the present invention is a process comprising the following process steps: a) Formulas A) and B) [ka] providing a compound of formula (I); b) reacting compounds A) and B) with each other in the presence of a base and a catalyst to obtain the compound of formula C): [ka] obtaining a compound of formula (I); c) reacting the compound of formula C) with hydrogen or a hydrogenation agent, in particular a hydride, and a ketone or aldehyde (R 1 =O) to give the compound D): [ka] obtaining a compound of formula (I); d) optionally reacting the compound of formula D) to form a compound of formula E): [ka] obtaining a compound of formula (I); e) reacting a compound of formula D) or E) with an acid to obtain a compound of formula I): [ka] A process for obtaining a compound of A method for preparing a compound of formula I comprising:

[0048] All of the foregoing are groups R 1 , R 2 , and R 3 and for the indices m and n.

[0049] The base in step b) is preferably selected from organic and inorganic bases. The inorganic bases are preferably selected from the group consisting of potassium carbonate, potassium phosphate, sodium carbonate, sodium phosphate, cesium carbonate.

[0050] The organic base is preferably selected from the group consisting of sodium tert-butoxide, potassium tert-butoxide.

[0051] The catalyst in step b) is preferably a catalyst which catalyzes via "copper coupling", such as, in particular, copper iodide.

[0052] Copper coupling preferably uses an inorganic base, such as copper iodide, as a catalyst in conjunction with the base potassium carbonate.

[0053] Similarly referred to as "palladium coupling", the catalyst optionally comprises a monodentate or polydentate ligand, in particular a monodentate or polydentate phosphine ligand. Suitable catalysts include, in particular and for example, triphenylphosphine and binaphthylphosphine (BINAP).

[0054] Copper coupling can use either inorganic or organic bases.

[0055] "Hydrogenation reagent" should be understood to mean a compound that brings about hydrogenation. Such reagents include hydrides, in particular metal hydrides, as known to those skilled in the art.

[0056] Suitable hydrides include, for example, sodium borohydride.

[0057] In the context of the present invention, hydrogen is explicitly mentioned as an alternative and is therefore not additionally listed under "hydrogenation reagents". Nevertheless, it will be understood that the term "hydrogenation reagents" encompasses all reagents that form hydrogen to perform in situ hydrogenation.

[0058] It is preferred if the reaction in step c) is carried out with hydrogen (H2) and a ketone or aldehyde, preferably a ketone, using a hydrogenation catalyst and preferably at a temperature of 50-70°C, in particular for example 60°C.

[0059] The reaction mixture is subjected to hydrogen at a pressure of 15 to 25 bar, in particular for example 20 bar, and then preferably stirred for 1 to 20 hours, preferably for 8 to 13 hours, in particular for example 10 hours.

[0060] In step c) the ketone is then reacted with the group R 1 in the case of an aldehyde it is therefore an aldehyde derivative.

[0061] For simplicity, the group R 1 is the moiety remaining on the nitrogen atom after reaction with an aldehyde or ketone, hence the abbreviated formula R 1 =O is used for aldehydes or ketones.

[0062] The ketone methyl isobutyl ketone is preferably used here.

[0063] The reaction with hydrogen in step c) is preferably carried out in a vessel suitable for relatively high pressures, such as in particular in an autoclave or another pressure reactor.

[0064] The solvent in step c) can be either the ketone or aldehyde, if it is in liquid form, or an inert solvent, such as toluene or xylene, especially if the ketone or aldehyde is in solid form. In the latter case, the ketone or aldehyde is used only as reactant in stoichiometric amounts.

[0065] It is preferable to use a ketone or an aldehyde, particularly preferably a ketone, in liquid form as solvent, which makes it possible to avoid additional substances such as toluene or xylene.

[0066] Process steps in which reaction with hydrogen is carried out are preferred where a suitable catalyst is used, which is referred to in the context of the present invention as a "hydrogenation catalyst".

[0067] The hydrogenation catalyst is preferably a noble metal catalyst, in particular palladium (Pd) or platinum (Pt). Noble metals are preferably used on carbon (C), such as palladium on carbon (Pd / C).

[0068] Additionally, other known catalysts such as Raney nickel or copper chromite may also be used.

[0069] The reaction with a base is optional. The compound of formula D) can also be reacted directly with an acid to obtain the target compound of formula I).

[0070] The acid used is particularly and preferably sulfuric acid (H2SO4).

[0071] However, the reaction according to step d) is preferably carried out first.

[0072] This makes it possible to achieve higher yields of the target compound of formula I).

[0073] The reaction of a compound of formula D) to give a compound of formula E) is an ester cleavage, which is preferably carried out with a suitable reagent therefor, in particular a base, such as sodium hydroxide (NaOH), or an acid, such as concentrated hydrochloric acid (concentrated HCl).

[0074] The reaction in step d) is preferably heated under reflux for several hours. The reaction is preferably heated for 4 to 12 hours, particularly preferably 6 to 10 hours, for example 8 hours (overnight), and then cooled.

[0075] The pH is then adjusted to 6.8 to 7.2, in particular to 7, preferably with ice cooling.

[0076] This is followed by extraction with a solvent. It is preferred to use 2-methyltetrahydrofuran (2-MTHF) and to carry out the extraction two or more times, in particular three times. The use of 2-methyltetrahydrofuran (2-MTHF) achieves a particularly high yield of the intermediate of formula E).

[0077] If step d) has been carried out previously, the reaction of the compound of formula E) is carried out with an acid, the acid used here being, for example and preferably, polyphosphoric acid (PPA).

[0078] It is preferred if the reaction in step e) is carried out at a temperature between 120°C and 140°C, for example at 130°C. The mixture is then preferably first cooled to a temperature between 50°C and 70°C, and the unreacted acid is hydrolyzed with water. The mixture is then further cooled, preferably to room temperature. The pH is then adjusted to 6.8 to 7.2, in particular to 7. This results in a particularly high yield of the target compound of formula I).

[0079] This is followed by extraction with a solvent. It is preferred to use 2-methyltetrahydrofuran (2-MTHF) and to carry out the extraction more than once, in particular twice. The use of 2-methyltetrahydrofuran (2-MTHF) likewise achieves a particularly high yield of the target compound).

[0080] The present invention further comprises at least the following process steps: a1) Formula A1) [ka] [wherein the above is the group R 2 , R 3 and indices m and n, where X is a halogen, in particular fluorine (F), chlorine (Cl) or bromine (Br). providing a compound of formula (I); b1) The compound of formula A1) is reacted with a base, in particular potassium carbonate (K2CO3), to give the compound of formula B1): [ka] obtaining a compound of formula (I); c1) Reacting the compound of formula B1) with hydrogen or a hydrogenation agent, in particular a hydride, and a ketone or aldehyde (R 1 =O) to form a compound of formula I): [ka] A process for obtaining a compound of Further methods for preparing compounds of formula I) are provided, comprising:

[0081] The base in step b1) is preferably a strong base, such as potassium carbonate (K2CO3) or potassium phosphate (K3PO4). It is particularly preferred to use potassium carbonate (K2CO3).

[0082] The reaction according to step b1) is preferably carried out in a polar solvent, in particular dimethylformamide (DMF) or dimethylsulfoxide (DMSO). Dimethylformamide (DMF) is particularly preferably used.

[0083] The reaction in step c1) is carried out with hydrogen and a ketone or aldehyde, preferably a ketone, using a hydrogenation catalyst and preferably at a temperature of 120-150° C., in particular 140° C. for example.

[0084] It is preferred if the reaction mixture is subjected to hydrogen at a pressure of 35 to 45 bar, in particular for example 40 bar, and then preferably stirred for 1 to 20 hours, preferably 8 to 13 hours, in particular for example 10 hours.

[0085] In step c) the ketone is reacted with the following radical R 1 in the case of an aldehyde, it is therefore an aldehyde derivative.

[0086] For simplicity, the radical R 1 is the moiety that remains on the nitrogen atom after reaction with an aldehyde or ketone, so it is represented by the simplified formula R 1 =O is used for aldehydes or ketones.

[0087] It is preferred here to use the ketone methyl isobutyl ketone.

[0088] Process steps in which reaction with hydrogen is carried out are preferred where a suitable catalyst is used, which is referred to in the context of the present invention as a "hydrogenation catalyst".

[0089] The hydrogenation catalyst is preferably a noble metal catalyst, in particular palladium (Pd) or platinum (Pt). Noble metals are preferably used on carbon (C), such as palladium on carbon (Pd / C).

[0090] Additionally, other known catalysts such as Raney nickel or copper chromite may also be used.

[0091] The solvent in step c1) can be either the ketone or aldehyde, if it is in liquid form, or an inert solvent such as toluene or xylene, especially if the ketone or aldehyde is in solid form. In the latter case, the ketone or aldehyde is used only in stoichiometric amounts as a reactant.

[0092] It is preferable to use as solvent a ketone or an aldehyde in liquid form, particularly preferably a ketone, which makes it possible to eject additional substances such as toluene or xylene.

[0093] The reaction product of the above process according to the invention is in particular a substance mixture comprising a compound of formula I), where step c1) or e) is preferably followed by purification, for example by column chromatography, for example on silica gel.

[0094] As mentioned above, the present invention further provides a rubber mixture.

[0095] The rubber mixtures according to the invention contain compounds of formula I), in particular of formula II). They can in principle be any rubber mixture in which the novel inventive compounds, in particular of formula I), in particular of formula II), act as ageing stabilizers and / or antiozonants with low toxicity.

[0096] The rubber mixtures of the present invention contain at least one rubber.

[0097] It is preferred if the rubber mixtures according to the invention contain from 0.1 to 10 phr, particularly preferably from 0.1 to 7 phr and very particularly preferably from 1 to 6 phr of compounds of the formula I), in particular of the formula II).

[0098] The unit "phr" (parts per 100 parts by weight of rubber) used in this document is the conventional designation of quantities for mixture formulations in the rubber industry. The dosage of parts by weight of individual substances is used in this document to include all high molecular weight (M w based on 100 parts by weight of the total mass of rubber (whose molecular weight exceeds 20,000 g / mol).

[0099] In an advantageous embodiment of the invention, the rubber mixture according to the invention contains at least one diene rubber.

[0100] Thus, the rubber mixture may contain a diene rubber or a mixture of two or more different diene rubbers.

[0101] Diene rubbers are rubbers formed by polymerizing or copolymerizing dienes and / or cycloalkenes and therefore containing C=C double bonds in either the backbone or in side groups.

[0102] The diene rubber is preferably natural polyisoprene (NR), synthetic polyisoprene (IR), epoxidized polyisoprene (ENR), butadiene rubber (BR), butadiene-isoprene rubber, solution polymerized styrene-butadiene rubber (SSBR), emulsion polymerized styrene-butadiene rubber (ESBR), styrene-isoprene rubber, molecular weight M wis selected from the group consisting of liquid rubber having a molecular weight greater than 20,000 g / mol, halobutyl rubber, polynorbornene, isoprene-isobutylene copolymer, ethylene-propylene-diene rubber, nitrile rubber, chloroprene rubber, acrylate rubber, fluororubber, silicone rubber, polysulfide rubber, epichlorohydrin rubber, styrene-isoprene-butadiene terpolymer, hydrogenated acrylonitrile butadiene rubber, and hydrogenated styrene-butadiene rubber.

[0103] Nitrile rubber, hydrogenated acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, halobutyl rubber and / or ethylene-propylene-diene rubber are used in particular in the manufacture of technical rubber articles, such as belts, drive belts and hoses and / or shoe soles, etc. Mixture compositions known to those skilled in the art for these rubbers, specific in terms of fillers, plasticizers, vulcanization systems and additives, are preferably employed.

[0104] The natural and / or synthetic polyisoprene of all embodiments can be cis-1,4-polyisoprene or 3,4-polyisoprene. However, it is preferred to use cis-1,4-polyisoprene with a cis-1,4 ratio of more than 90% by weight. Firstly, such polyisoprene is accessible by stereospecific polymerization in solution with Ziegler-Natta catalyst or with fine lithium alkyl. Secondly, natural rubber (NR) is such cis-1,4-polyisoprene that the cis-1,4 content in natural rubber is more than 99% by weight.

[0105] Mixtures of one or more natural polyisoprenes with one or more synthetic polyisoprenes are further contemplated.

[0106] In the context of the present invention, the term "natural rubber" should be understood to mean natural rubber obtainable from the Hevea rubber tree and from "non-Hevea" sources, such as the guayule shrub and dandelions, such as TKS (Taraxacum kok-saghyz).

[0107] If the rubber mixture of the present invention contains butadiene rubber (i.e. BR, polybutadiene), this may be of any type known to those skilled in the art. These include those called high-cis and low-cis types, where polybutadienes with a cis content of 90% or more by weight are called high-cis types and polybutadienes with a cis content of less than 90% by weight are called low-cis types. An example of a low-cis polybutadiene is Li-BR (lithium catalyzed butadiene rubber) with a cis content of 20% to 50% by weight. With high-cis BR, particularly good properties and low hysteresis are achieved in the rubber mixture.

[0108] The polybutadienes employed may be end-group-modified and / or functionalized along the polymer chain with modifications and functionalizations. The modifications may be selected from modifications with hydroxyl groups and / or ethoxy groups and / or epoxy groups and / or siloxane groups and / or amino groups and / or aminosiloxane and / or carboxyl groups and / or phthalocyanine groups and / or silane-sulfide groups. However, further modifications known to those skilled in the art, also called functionalizations, are also useful. Metal atoms may be constituents of such functionalizations.

[0109] If at least one styrene-butadiene rubber (styrene-butadiene copolymer) is present in the rubber mixture, it may be selected from solution-polymerized styrene-butadiene rubber (SSBR) and emulsion-polymerized styrene-butadiene rubber (ESBR), it being possible to employ a mixture of at least one SSBR and at least one ESBR. The terms "styrene-butadiene rubber" and "styrene-butadiene copolymer" are used synonymously in the context of the present invention.

[0110] The styrene-butadiene copolymers employed may be end-group-modified and / or functionalized along the polymer chain by the modifications and functionalizations mentioned above for polybutadiene.

[0111] The at least one diene rubber is preferably selected from the group consisting of natural polyisoprene (NR, natural rubber), synthetic polyisoprene (IR), butadiene rubber (BR), solution polymerized styrene-butadiene rubber (SSBR), emulsion polymerized styrene-butadiene rubber (ESBR), butyl rubber (IIR) and halobutyl rubber.

[0112] In a particularly preferred embodiment of the present invention, the at least one diene rubber is selected from the group consisting of natural polyisoprene (NR), synthetic polyisoprene (IR), butadiene rubber (BR), solution polymerized styrene-butadiene rubber (SSBR) and emulsion polymerized styrene-butadiene rubber (ESBR).

[0113] In a particularly advantageous embodiment of the invention, the rubber mixture comprises at least one natural polyisoprene (NR) and / or synthetic polyisoprene (IR) preferably in an amount of 50 to 100 phr, in one particularly advantageous embodiment of the invention in an amount of 80 to 100 phr, very particularly preferably 95 to 100 phr, then preferably 100 phr. Such rubber mixtures exhibit in particular optimized tear and wear properties combined with good processability and reversion stability.

[0114] If the rubber mixture contains less than 100 phr of NR and / or IR, the rubber mixture preferably contains, as further rubber, at least one diene rubber selected from the group consisting of butadiene rubber (BR), solution polymerized styrene-butadiene rubber (SSBR) and emulsion polymerized styrene-butadiene rubber (ESBR).

[0115] In a further particularly advantageous embodiment of the invention, the rubber mixture comprises at least one natural polyisoprene (NR), preferably in an amount of 5 to 55 phr, and in one particularly advantageous embodiment of the invention in an amount of 5 to 25 phr, very particularly preferably in an amount of 5 to 20 phr. Such rubber mixtures exhibit particularly good processability and reversion stability as well as optimized tear properties and optimal rolling resistance characteristics.

[0116] In a further particularly advantageous embodiment of the invention, the rubber mixture comprises at least one polybutadiene (BR, butadiene rubber), preferably in an amount of 10 to 80 phr, particularly preferably 10 to 50 phr and in a particularly advantageous embodiment of the invention in an amount of 15 to 40 phr, whereby particularly good tear and wear properties as well as optimal braking characteristics of the rubber mixture according to the invention are achieved.

[0117] In a further particularly advantageous embodiment of the invention, the rubber mixture comprises at least one solution polymerized styrene-butadiene rubber (SSBR), preferably in an amount of 10 to 80 phr, particularly preferably 30 to 80 phr, and in one particularly advantageous embodiment of the invention in an amount of 50 to 70 phr. This achieves particularly good rolling resistance properties of the rubber mixture according to the invention. In a particularly advantageous embodiment of the invention, the SSBR is employed in combination with at least one further rubber in order to achieve an optimal and balanced property profile.

[0118] It is preferred if the rubber mixture contains at least one filler, preferably in an amount of 30 to 500 phr, particularly preferably in an amount of 50 to 400 phr, then preferably in an amount of 80 to 300 phr.

[0119] In an advantageous embodiment of the invention, the filler is a reinforcing filler, preferably selected from the group consisting of carbon black and silicon dioxide.

[0120] Suitable carbon blacks include any carbon black type known to those skilled in the art. It is preferred if the carbon black is selected from technical carbon black and pyrolytic carbon black, with technical carbon black being more preferred.

[0121] The carbon black preferably has an iodine value according to ASTM D1510, also known as iodine adsorption, of 30 to 250 g / kg, preferably 30 to 180 g / kg, particularly preferably 40 to 180 g / kg, and further particularly preferably 40 to 130 g / kg, and a DBP value according to ASTM D2414 of 30 to 200 ml / 100 g, preferably 70 to 200 ml / 100 g, and particularly preferably 90 to 200 ml / 100 g.

[0122] The DBP value according to ASTM D2414 determines the specific absorption volume of dibutyl phthalate in carbon black or light colored fillers.

[0123] The use of such types of carbon black in rubber mixtures, particularly for vehicle tires, ensures an optimal compromise between wear resistance and heat storage, which in turn affects the ecologically relevant rolling resistance.

[0124] Particularly suitable and preferred carbon blacks are those having an iodine adsorption number of 80 to 110 g / kg and a DBP number of 100 to 130 ml / 100 g, such as in particular carbon black of type N 339.

[0125] The silicon dioxide is preferably amorphous silicon dioxide, for example precipitated silica, also called precipitated silicon dioxide. However, it is alternatively possible to use, for example, pyrogenic silicon dioxide.

[0126] However, it is particularly preferred to use finely divided precipitated silicas having a nitrogen surface area (BET surface area) (according to DIN ISO 9277 and DIN 66132) of 35 to 400 m2 / g, preferably 35 to 350 m2 / g, more preferably 85 to 320 m2 / g, most preferably 120 to 235 m2 / g and a CTAB surface area (according to ASTM D 3765) of 30 to 400 m2 / g, preferably 30 to 330 m2 / g, more preferably 80 to 300 m2 / g, most preferably 115 to 200 m2 / g. Such silicas result in particularly good physical properties of the vulcanized rubber, for example in rubber mixtures for tire treads. Advantages in the processing of the mixtures due to shortened mixing times can also be obtained while maintaining the same product properties, resulting in improved productivity. The silica used can thus be, for example, Ultrasil® VN3 type (trade name) from Evonik, or highly disperse silica known as HD silica (for example Zeosil® 1165MP from Solvay).

[0127] In a particularly advantageous embodiment of the invention, the rubber mixture contains at least one silica as filler, preferably in an amount of 30 to 500 phr, particularly preferably in an amount of 50 to 400 phr, then preferably in an amount of 80 to 300 phr.

[0128] In these amounts, silica is especially present as the sole or predominant filler (greater than 50% by weight, based on the total amount of filler).

[0129] In a further advantageous embodiment of the invention, the rubber mixture contains at least one silica as further filler, preferably in an amount of 5 to 100 phr, particularly preferably 5 to 80 phr, then preferably 10 to 60 phr.

[0130] In these amounts, the silica is particularly present as an additional filler, especially in addition to other primary fillers such as carbon black.

[0131] The terms "silicic acid" and "silica" are used synonymously in the context of the present invention.

[0132] In a particularly advantageous embodiment of the invention, the rubber mixture according to the invention contains from 0.1 to 60 phr, preferably from 3 to 40 phr, particularly preferably from 5 to 30 phr and very particularly preferably from 5 to 15 phr of at least one carbon black. In these amounts, the carbon black is in particular present as a further filler, in addition to the main filler, such as silica.

[0133] In a further advantageous embodiment of the invention, the rubber mixture according to the invention contains from 30 to 300 phr, preferably from 30 to 200 phr, particularly preferably from 40 to 100 phr, of at least one carbon black, in these amounts being present alone or as the main filler, optionally in combination with silica in the amounts towards the lower limits mentioned above.

[0134] In a particularly advantageous embodiment of the invention, the rubber mixture contains from 5 to 60 phr, particularly preferably from 5 to 40 phr, of at least one carbon black and from 50 to 300 phr, preferably from 80 to 200 phr, of at least one silica.

[0135] The rubber mixture may further contain further reinforcing or non-reinforcing fillers.

[0136] In the context of the present invention, further (non-reinforcing) fillers include aluminosilicates, kaolin, chalk, starch, magnesium oxide, titanium dioxide, or rubber gels and fibres (eg aramid fibres, glass fibres, carbon fibres, cellulose fibres).

[0137] Further optionally, the reinforcing fillers are carbon nanotubes (CNTs), including, for example, discrete CNTs, so-called hollow carbon fibers (HCFs), and modified CNTs containing one or more functional groups such as hydroxyl, carboxyl, and carbonyl groups, graphite and graphene, and so-called "carbon-silica dual phase fillers."

[0138] In the context of the present invention, zinc oxide is not included in the filler.

[0139] The rubber mixture may further contain conventional additives in conventional parts by weight, which are preferably added in at least one primary mixing stage during the preparation of said mixture. These additives include: a) ageing stabilizers known in the art, For example, p-phenylenediamines, such as N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N-(1-phenylethyl)-N'-phenyl-p-phenylenediamine (SPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine (7PPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), or dihydroquinolines, such as 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), b) activators, such as zinc oxide and fatty acids (e.g. stearic acid) and / or other activators, such as zinc complexes, such as zinc ethylhexanoate; c) activators and / or agents for binding fillers, in particular carbon black or silica, such as S-(3-aminopropyl)thiosulfate and / or its metal salts (carbon black binding) and silane coupling agents (silica binding); d) antiozonant waxes; e) resins, especially tackifying resins; f) mastication aids, such as 2,2'-dibenzamidodiphenyl disulfide (DBD); g) processing aids, in particular fatty acid esters and metal soaps, for example zinc soaps and / or calcium soaps; h) plasticizers, for example in particular aromatic, naphthenic or paraffinic mineral oil plasticizers, for example MES (Mild Extraction Solvates), preferably having a content of polycyclic aromatic compounds of less than 3% by weight according to method IP 346, or RAE (Residual Aromatic Extract), or TDAE (Processed Distillate Aromatic Extract), or Rubber to Liquid (RTL) oils or Biomass to Liquid (BTL) oils, or triglycerides, for example rapeseed oil or factice, or hydrocarbon resins or liquid polymers with an average molecular weight (determined by GPC = Gel Permeation Chromatography in accordance with BS ISO 11344:2004) of 500 to 20 000 g / mol.

[0140] If a mineral oil is used, it is preferably selected from the group consisting of DAE (distillate aromatic extract), RAE (residual aromatic extract), TDAE (treated distillate aromatic extract), MES (light extract solvate), and naphthenic oils.

[0141] In a particularly advantageous embodiment, the rubber mixture according to the invention does not contain, in addition to the inventive compounds of formula I), in particular of formula II), ageing stabilizers from the group of p-phenylenediamines, in particular those listed above under a). In a particularly preferred embodiment, the rubber mixture according to the invention contains 0 to 0.1 phr, in particular 0 phr, of further ageing stabilizers based on p-phenylenediamines, preferably selected from the group consisting of, in particular, N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N-(1-phenylethyl)-N'-phenyl-p-phenylenediamine (SPPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine (7PPD).

[0142] The very small amounts of p-phenylenediamine, preferably 0-0.1 phr, particularly preferably 0 phr, present according to the invention, as well as the compounds of formula I), in particular of formula II), make it possible to achieve an equivalent protective effect with lower toxicity.The inventive compounds of formula I), in particular of formula II), replace the listed p-phenylenediamines known in the prior art.

[0143] In a further advantageous embodiment of the present invention, since at least one further representative of the listed p-phenylenediamine aging stabilizers is present, the compounds according to the invention only partially replace the p-phenylenediamines known in the prior art, which also achieve the advantages according to the present invention, but only to a less than optimal extent.

[0144] In an advantageous embodiment, an ageing stabilizer of the dihydroquinoline type, such as TMQ, is present in the rubber mixture in addition to the compound of formula I) according to the invention. The amount of dihydroquinoline, in particular TMQ, present is preferably from 0.1 to 3, in particular from 0.5 to 1.5 phr.

[0145] The antiozonant waxes (group d above) are considered separately and, in a preferred embodiment of the invention, are present in the rubber mixture regardless of whether or not additional ageing stabilizers a) are present.

[0146] The silane coupling agent may be of any type known to those skilled in the art.

[0147] Additionally, one or more different silane coupling agents may be used in combination with one another, so that a rubber mixture may contain a mixture of different silanes.

[0148] Silane coupling agents react with surface silanol groups or other polar groups of silicon dioxide, especially silica, during mixing of the rubber / rubber mixture (in situ) or in pretreatment (pre-modification) situations, even before the addition of the filler to the rubber.

[0149] Coupling agents known from the prior art are bifunctional organosilanes which have at least one alkoxy, cycloalkoxy or phenoxy group as leaving group on the silicon atom and other functional groups which, possibly after cleavage, are capable of entering into a chemical reaction with the double bonds of the polymer. The latter groups may include, for example, the following chemical groups: -SCN, -SH, -NH2 or -S x -(where x=2~8).

[0150] The silane coupling agents which can be used are therefore, for example, 3-mercaptopropyltriethoxysilane, 3-thiocyanatopropyltrimethoxysilane or 3,3'-bis(triethoxysilylpropyl) polysulfides having 2 to 8 sulfur atoms, such as 3,3'-bis(triethoxysilylpropyl)tetrasulfide (TESPT), the corresponding disulfides (TESPD) or other mixtures of sulfides having 1 to 8 sulfur atoms with different sulfides. TESPT can also be added, for example, as a mixture with industrial carbon black (trade name X50S®, manufactured by Evonik).

[0151] Blocked mercaptosilanes, such as known from WO 99 / 09036, can also be used as silane coupling agents. It is also possible to use silanes described in WO 2008 / 083241A1, WO 2008 / 083242A1, WO 2008 / 083243A1 and WO 2008 / 083244A1. Usable silanes include, for example, those sold by Momentive in the USA in numerous variants under the name NXT, such as in particular 3-octanoylthio-1-propyltriethoxysilane, or those sold by Evonik Industries under the name VP Si 363®.

[0152] The total proportion of further additives is preferably between 3 and 150 phr, more preferably between 3 and 100 phr, most preferably between 5 and 80 phr.

[0153] Zinc oxide (ZnO) may be included in the overall proportion of further additives in the amounts mentioned above.

[0154] This can be any type of zinc oxide known to the person skilled in the art, for example ZnO granules or powder. Conventionally used zinc oxides usually have a BET specific surface area of ​​less than 10 m2 / g. However, it is also possible to use zinc oxides with a BET surface area of ​​10 to 100 m2 / g, for example the so-called "nano zinc oxide".

[0155] The rubber mixtures of the present invention are preferably used in vulcanized form, especially for vehicle tires or other vulcanized industrial rubber articles.

[0156] The terms "vulcanization" and "crosslinking" are used synonymously in the context of the present invention.

[0157] The vulcanization of the rubber mixture of the present invention is preferably carried out in the presence of sulfur and / or sulfur donors with the aid of vulcanization accelerators, some of which can simultaneously act as sulfur donors, selected from the group consisting of thiazole vulcanization accelerators, mercapto vulcanization accelerators, sulfenamide vulcanization accelerators, thiocarbamate vulcanization accelerators, thiuram vulcanization accelerators, thiophosphate vulcanization accelerators, thiourea vulcanization accelerators, xanthogenate vulcanization accelerators and guanidine vulcanization accelerators.

[0158] It is preferred to use a sulfenamide accelerator selected from N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), N,N-dicyclohexylbenzothiazole-2-sulfenamide (DCBS), benzothiazyl-2-sulfenamide morpholide (MBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and guanidine accelerators such as diphenylguanidine (DPG).

[0159] The sulfur donor material used can be any sulfur donor material known to those of skill in the art.

[0160] Vulcanization retarders may also be present in the rubber mixture.

[0161] In other cases, the preparation of the rubber mixture according to the invention is preferably carried out by processes customary in the rubber industry, which include first preparing a primary mixture in one or more mixing stages, which contains all the components except the vulcanization system (e.g. sulfur and vulcanization-influencing substances), and the final mixture is produced by adding the vulcanization system in the final mixing stage.

[0162] The final mixture may be further processed, for example, and brought into a suitable shape by an extrusion operation or by calendering.

[0163] The rubber mixture according to the invention is particularly suitable for use in vehicle tires, especially pneumatic vehicle tires.In principle, its use in all tire components, especially outer components, particularly preferably in the flange profile, tread and / or sidewall, is conceivable.In the case of treads with a cap / base structure, the rubber mixture according to the invention is preferably used at least in the cap.

[0164] For use in vehicle tires, the mixture as a finished pre-vulcanized mix is ​​preferably formed into the corresponding shape of the outer component and applied in known manner during the manufacture of green vehicle tires.

[0165] The production of the rubber mixture according to the invention for use as any other body mixture in vehicle tires is carried out as described above. The difference lies in the shaping after the extrusion operation / calendering of the mixture. The shape of the not yet vulcanized rubber mixture thus obtained for one or more different body mixtures is then subjected to the production of green tires.

[0166] Here, "body mix" refers essentially to the rubber mix for the inner components of the tire, such as the squeegee, inner liner (inner layer), core profile, belt, shoulder, belt profile, carcass, bead reinforcement, bead profile, flange profile and bandage.

[0167] The green tire, which is not yet cured, is then cured.

[0168] For the use of the rubber mixture of the invention in drive belts and other belts, especially conveyor belts, the extruded, not yet vulcanized mixture is brought into a suitable shape and is often provided, simultaneously or subsequently, with reinforcing elements, such as synthetic fibers or steel cords, usually resulting in a multi-ply structure consisting of one and / or more plies of the rubber mixture, one and / or more plies of identical and / or different reinforcing elements and one and / or more further plies of the same and / or other rubber mixtures.

[0169] The present invention further provides a vehicle tyre comprising a rubber mixture according to the invention containing in at least one of its constituents a compound according to the invention.

[0170] The vulcanized vehicle tire in at least one component contains a vulcanizate of at least one rubber mixture according to the invention. It is known to those skilled in the art that most substances present, such as rubber, may be present already after mixing or only after vulcanization in a chemically modified form.

[0171] In the context of the present invention, "vehicle tires" should be understood to mean pneumatic vehicle tires and solid rubber tires, including industrial tires, as well as tires for construction vehicles, trucks, cars and motorcycles.

[0172] It is preferred if the vehicle tyre according to the invention comprises the rubber mixture according to the invention in at least one external component, which external component is preferably the tread, the sidewall and / or the flange profile.

[0173] Thus, the vehicle tyre according to the invention may comprise the rubber mixture according to the invention comprising the inventive compound of formula I), in particular of formula II), in several components, optionally in a compatible composition. EXAMPLES

[0174] The present invention will now be more specifically clarified with reference to the following examples.

[0175] The compound of formula II) as a preferred embodiment of the compound of formula I) was prepared according to the first synthetic route as follows: Synthesis of 2-(p-phenylenediamine)-methylbenzoate- according to scheme XI: [ka]

[0176] The two starting materials are commercially available.

[0177] In 20 mL of dry dimethylsulfoxide (DMSO) 1.6 g (14.5 mmol, 2.0 eq) of p-phenylenediamine and 1.9 g of 2-iodomethylbenzoate (7.24 mmol, 1.0 eq) were initially charged. After addition of 1.00 g of potassium carbonate (K2CO3) (7.24 mmol, 1.0 eq) and 0.14 g of copper iodide (CuI) (0.72 mmol, 0.1 eq), the mixture was stirred at 80° C. overnight. After completion of the reaction, the solvent was distilled off and the residue was taken up in a mixture of ethyl acetate and 5% by weight aqueous ammonia. Before drying over sodium sulfate, the organic phase was extracted again with 5% ammonia solution, water and saturated sodium chloride solution. The inorganic salts were separated by filtration and the solvent was removed under vacuum. The residue was purified by column chromatography on silica gel (dichloromethane (DCM) / methanol (MeOH) 95:5). Orange oil; yield 1.6 g (91% of theory). 1H-NMR (Nuclear Magnetic Resonance) (500MHz, DMSO-d6) δ=9.00(s,1H),7.83(dd,J=8.6,1.7Hz,1H),7.29(ddd,J=8.6,7.0,1.7 Hz,1H),6.91(d,J=8.5Hz,2H),6.79(dd,J=8.6,1.1Hz,1H),6.67-6.56(m,3H),5.07(s,2H),3.84(s,3H). 13 C-NMR(126MHz,DMSO-d6)δ=168.7,150.4,146.9,134.9,128.4,126.6,116.0,115.1,113.4,110.0,52.2.

[0178] Scheme XII) of 2-(N 1 -(4-Methylpentan-2-yl)-N 4 Synthesis of (p-phenylenediamine)-methyl benzoate: [ka]

[0179] 6.80 g (28.1 mmol, 1 eq) of 2-(p-phenylenediamine)-methylbenzoate, 1.18 g of palladium on carbon (Pd / C) (5%) (0.2 g for 4.67 mmol of substrate) and 50.0 mL of methyl isobutyl ketone (MIBK) were weighed into a stainless steel autoclave equipped with a Teflon liner. The reaction mixture was then subjected to hydrogen (H2) at a pressure of 20 bar and stirred at 60° C. for 10 hours. At the end of the reaction, the excess hydrogen was released and the suspension was filtered through Celite® and washed with ethanol. The filtrate was evaporated to dryness and dried under vacuum. The residue was purified by column chromatography on silica gel (cyclohexane / EE (ethyl acetate) 95:5). An orange oil was obtained; yield 8.20 g (89% of theory). 1H NMR(500MHz,DMSO-d6)δ=9.01(s,1H),7.83(dd,J=8.1,1.7Hz,1H),7.30(ddd,J=8.7,7.0,1.7Hz ,1H),6.95(d,J=8.7Hz,2H),6.81(dd,J=8.6,1.1Hz,1H),6.66-6.56(m,3H),5.32(d,J=8.6Hz,1 H),3.84(s,3H),3.44(dq,J=8.6,6.7Hz,1H),1.74(dt,J=13.4,6.7Hz,1H),1.46(dt,J=14.0,7. 1Hz,1H),1.27-1.16(m,1H),1.09(d,J=6.2Hz,3H),0.92(d,J=6.6Hz,3H),0.88(d,J=6.6Hz,3H). 13 C-NMR(126MHz,DMSO-d6)δ=168.7,150.4,146.6,134.9,131.6,127.7,126 .8,116.0,113.4,113.3,109.9,52.2,46.4,46.0,25.00,23.2,23.1,21.2. ES-IMS (Electrospray Ionization Mass Spectrometry) [M+H] + =327.

[0180] Scheme XII) of 2-(N 1 -(4-Methylpentan-2-yl)-N 4 Synthesis of (p-phenylenediamine)-benzoic acid: [ka]

[0181] 3.90 g of 2-(N) in 40 mL of degassed dioxane and 50 mL of degassed aqueous sodium hydroxide (NaOH) (2 molar). 1 -(4-Methylpentan-2-yl)-N 4-p-phenylenediamine)-methylbenzoate (12.0 mmol, 1 eq) was heated under reflux overnight. Once the reaction had reached room temperature (RT), the pH was adjusted to pH 7 with ice cooling. The mixture was extracted three times with 2-methyltetrahydrofuran (2-MTHF) and the combined organic phases were extracted with water and saturated sodium chloride solution and dried over sodium sulfate. A dark green solid was obtained; yield 3.70 g (99% of theory). 1 H-NMR(500MHz,DMSO-d6)δ=10.91(br s,1H),7.85(dd,J=7.7,1.8Hz,1H),7.04(ddd,J=8.6,7.0,1.8Hz,1H),6.89(d,J=8.7Hz,2H), 6.81(dd,J=8.3,1.1Hz,1H),6.55(d,J=8.7Hz,2H),6.48(ddd,J=8.0,7.1,1.2Hz,1H),5.05(br s,1H),3.41(q,J=6.5Hz,1H),1.74(dt,J=13.5,6.7Hz,1H),1.45(dt,J=13.4,7.1Hz,1H),1.2 1(dt,J=13.5,6.9Hz,1H),1.08(d,J=6.1Hz,3H),0.92(d,J=6.7Hz,3H),0.88(d,J=6.5Hz,3H). 13 C-NMR(126MHz,DMSO)δ=172.1,148.8,144.9,132.4,130.9,130.8,124.4,115.0,113.5,111.9,46.5,46.2,25.0,23.2,23.1,21.2. ESI-MS [M+H] + =313.

[0182] Synthesis of 2-(1,3-dimethylbutylamino)-acridin-9(10H)-one (compound of formula II) according to scheme XIV: [ka]

[0183] 7.80 g of 2-(N 1 -(4-Methylpentan-2-yl)-N 4-p-Phenylenediamine)-benzoic acid (25.0 mmol, 1 eq) was stirred in 40 mL of polyphosphoric acid (PPA) at 130 °C for 16 h. Once the reaction was at 60 °C, the PPA was slowly hydrolyzed by addition of water. The solution was then cooled to RT and the pH was adjusted to 7. The mixture was extracted three times with 2-MTHF and the combined organic phases were extracted with water and saturated sodium chloride solution and dried over sodium sulfate. The inorganic salts were removed by filtration and the solvent was removed under vacuum. The residue was then purified by column chromatography on silica gel (cyclohexane / EE+1% triethylamine (TEA) or cyclohexane / tetrahydrofuran (THF)+1% TEA). A yellow-bronze solid was obtained; yield 5.30 g (72% of theory). 1 H-NMR(500MHz,DMSO-d6)δ=11.47(s,1H),8.19(dd,J=8.2,1.5Hz,1H),7.62(ddd,J=8.4,6.8,1 .6Hz,1H),7.47(d,J=8.4Hz,1H),7.37(d,J=8.8Hz,1H),7.24-7.09(m,3H),5.48(d,J=8.3Hz,1 H),3.51(dq,J=7.8,6.3Hz,1H),1.77(dt,J=13.4,6.7Hz,1H),1.51(dt,J=13.9,7.1Hz,1H),1. 26(dt,J=13.6,6.8Hz,1H),1.14(d,J=6.2Hz,3H),0.95(d,J=6.6Hz,3H),0.89(d,J=6.6Hz,3H). 13 C-NMR(126MHz,DMSO)δ=176.4,143.7,140.5,133.2,132.7,126.4,123.8,12 2.3,120.3,119.8,118.8,117.6,102.9,46.3,46.2,25.0,23.2,23.1,20.9. ESI-MS [M+H] + =295.

[0184] 2-(N 1 -(4-Methylpentan-2-yl)-N 4Alternative synthesis of 2-(1,3-dimethylbutylamino)-acridin-9(10H)-one (compound of formula II) from -p-phenylenediamine)-methylbenzoate: [ka]

[0185] 4.70g of 2-(N 1 -(4-Methylpentan-2-yl)-N 4 -p-Phenylenediamine)-methylbenzoate (2.14 mmol, 1 eq) was dissolved in 40 mL of sulfuric acid (H2SO4) (13.5 M) and stirred at 115 °C for 16 h. Once the reaction had reached RT, the pH was adjusted to pH 7 with ice cooling. The mixture was extracted three times with 2-MTHF and the combined organic phases were extracted with water and saturated sodium chloride solution and dried over sodium sulfate. The inorganic salts were removed by filtration and the solvent was removed under vacuum. The residue was then purified by column chromatography on silica gel (cyclohexane / EE+1% TEA) or cyclohexane / THF+1% TEA). A yellow-bronze solid was obtained; yield 2.90 g (69% of theory). 1 H-NMR(500MHz,DMSO-d6)δ=11.47(s,1H),8.19(dd,J=8.2,1.5Hz,1H),7.62(ddd,J=8.4,6.8,1 .6Hz,1H),7.47(d,J=8.4Hz,1H),7.37(d,J=8.8Hz,1H),7.24-7.09(m,3H),5.48(d,J=8.3Hz,1 H),3.51(dq,J=7.8,6.3Hz,1H),1.77(dt,J=13.4,6.7Hz,1H),1.51(dt,J=13.9,7.1Hz,1H),1. 26(dt,J=13.6,6.8Hz,1H),1.14(d,J=6.2Hz,3H),0.95(d,J=6.6Hz,3H),0.89(d,J=6.6Hz,3H). 13C-NMR(126MHz,DMSO)δ=176.4,143.7,140.5,133.2,132.7,126.4,123.8,12 2.3,120.3,119.8,118.8,117.6,102.9,46.3,46.2,25.0,23.2,23.1,20.9. ESI-MS [M+H] + =295.

[0186] Following a further synthetic route, compounds of formula II) were synthesized as follows:

[0187] First, 2-nitroacridin-9(10H)-one is reacted with 2-nitroacridin-9(10H)-one according to Scheme YI): [ka] (Here, K2CO3 represents potassium carbonate and DMF represents dimethylformamide.) The compound was synthesized according to R. Freyer J. Chem. 1963, 4979-5004 as shown in.

[0188] This is Scheme YII): [ka] was used for the synthesis of 2-(1,3-dimethylbutylamino)-acridin-9(10H)-one (compound of formula II) according to

[0189] 0.55 g (2.62 mmol, 1 eq) of 2-nitroacridin-9(10H)-one, 0.23 g of platinum (5%) (0.4 g for 4.67 mmol of substrate) and 20.0 mL of methyl isobutyl ketone were weighed into a stainless steel autoclave equipped with a Teflon liner. The reaction mixture was then subjected to hydrogen at a pressure of 40 bar and stirred at 140° C. for 10 h. At the end of the reaction, the excess hydrogen was released and the suspension was filtered through Celite® and washed with ethanol. The filtrate was evaporated to dryness and dried under vacuum. The residue was analyzed by LC-MS. The results are shown in Table 1.

[0190] The material can be purified by column chromatography on silica gel (cyclohexane / ethyl acetate 10:1→1:1). Pale yellow solid.

[0191] [Table 1]

[0192] Measurement of oxidative induction time (OIT) The compound of formula II) was studied under laboratory conditions with regard to its potential protective effect as an ageing stabilizer by measuring the oxidation induction time.

[0193] For this purpose, the compound of formula II) as well as 6-PPD were in each case mixed with a polymer (liquid synthetic polyisoprene (IR), LIR-50, Kuraray, weight average molecular weight distribution M w = 54000g / mol, glass transition temperature T g =-63°C) and heated at a constant temperature (180°C) until the onset of oxidation (starting temperature 35°C, heating rate of 20 K / min (Kelvin / min) to 170°C, heating rate of 1 K / min to 180°C; purge gas: nitrogen (N2), volume flow rate 50 ml / min).

[0194] The specimen was isothermally maintained at 180° C. under N2 atmosphere, and then the atmosphere was switched to O2 atmosphere (volume flow rate 50 ml / min).

[0195] DSC (differential scanning calorimetry) was used to determine the oxidation via peaks.

[0196] The time (min) until oxidation was measured.

[0197] The results compared with the known aging stabilizer 6-PPD are summarized in Table 2.

[0198] [Table 2]

[0199] Taking into account a measurement accuracy of ±(plus / minus) 10 minutes, it is clear that the compound of formula II) actually achieves a significantly better protective effect, since it takes longer for the polymer to be decomposed by oxygen. The inventive compounds of formula I) / formula II) are therefore more environmentally friendly and less harmful to health than further representatives of the 6-PPD / substance class as mentioned above, and are also better ageing stabilizers.

[0200] For use in rubber mixtures for vehicle tyres, the compounds of the invention of formula I), e.g. of formula II), are added in one of the mixing stages during the preparation of the rubber mixture in a manner known to those skilled in the art, instead of the ageing stabilizers known from the prior art, such as, for example, 6PPD, 7PPD or IPPD.

[0201] Therefore, compounds of formula II) were incorporated into exemplary rubber mixtures according to the invention, as shown in Table 3. The resulting examples of the invention are labeled E1.

[0202] Serving as a comparison is rubber mixture V1 which contains 6PPD instead of the compound of formula II) as ageing stabilizer, the rest of the composition being identical. The amounts in Table 3 are expressed in phr.

[0203] The mixtures were prepared according to the process customary in the rubber industry in laboratory mixers with a volume of 300 ml to 3 liters under standard conditions in three stages: in the first mixing stage (premixing stage), all the components except the vulcanization system (sulfur and vulcanization-affecting substances) were mixed at 145°C to 165°C, with a target temperature of 152°C to 157°C, for 200 to 600 seconds. In the second stage, the mixture from the first stage was mixed again. In the third stage (final mixing stage), the vulcanization system was added, the final mixture was obtained, and mixing was carried out at 90°C to 120°C for 180 to 300 seconds.

[0204] Test specimens were produced from all mixtures by vulcanization under pressure at 160°C–170°C after t95–t100 (measured using a moving die rheometer according to ASTM D 5289-12 / ISO 6502).

[0205] Also, some of the specimens of both V1 and E1 were aged (70°C in air for 28 days).

[0206] For all specimens the following material properties typical for the rubber industry were determined: Resilience at room temperature (RT) according to ISO 4662 or ASTM D 1054 Elongation at break at room temperature (RT) according to DIN 53 504

[0207] For V1 and E1, the difference between the values ​​of the unaged and aged samples was determined in each case.

[0208] The values ​​obtained for V1 were in each case normalized to 100% for reference.

[0209] The values ​​obtained for E1 (difference between unaged and aged) are reported as % performance against this respective V1 criterion, with values ​​above 100% being favored.

[0210] As is evident from Table 3, the inventive compounds of formula II), as representative of the compounds of formula I), provide improved aging stabilization, since important properties such as elongation at break and rebound resilience are in each case at higher levels in E1 than in V1 after aging.

[0211] [Table 3]

Claims

1. Formula I): 【Chemical 1】 [In the formula, R １ teeth, xi) aromatic group, and xii) branched and cycloaliphatic C ４ ~C １２ basis, and xiii) an aromatic group and an aliphatic C １ ~C １２ Combination with groups wherein the group R ２ and R ３ may be the same or different, independently of one another, and may be linear, branched, or cyclic, saturated or unsaturated, aliphatic C １ ~C １２ and aryl groups, wherein n has a value of 0 or 1 or 2 or 3 or 4, and when n is 2 or 3 or 4, the group R ３ are, independently of one another, identical or different, In the formula, m takes the value 0 or 1 or 2 or 3, and when m is 2 or 3, the group R ２ are, independently of each other, identical or different.

1. A rubber mixture containing a compound of formula (I) above, which contains at least one diene rubber.

2. 2. A rubber mixture according to claim 1, characterized in that n is 0 (zero).

3. 3. A rubber mixture according to claim 1, wherein m is 0 (zero).

4. R １ 3. Rubber mixture according to claim 1 or 2, characterized in that is linked to the nitrogen atom (N) via a tertiary carbon atom.

5. R １ 3. Rubber mixture according to claim 1, characterized in that is a branched alkyl radical having from 4 to 12 carbon atoms.

6. R １ 3. A rubber mixture according to claim 1, wherein is selected from 1,3-dimethylbutyl radicals and cyclohexyl radicals.

7. The compound has formula II: 【Chemistry 2】 3. A rubber mixture according to claim 1 or 2, characterized in that it has the structure

8. 3. The rubber mixture according to claim 1 or 2, which contains at least one diene rubber selected from the group consisting of natural polyisoprene (NR rubber), synthetic polyisoprene (IR), butadiene rubber (BR), solution-polymerized styrene-butadiene rubber (SSBR), emulsion-polymerized styrene-butadiene rubber (ESBR), butyl rubber (IIR) and halobutyl rubber.

9. A vehicle tire comprising, at least in one of its components, a rubber mixture according to claim 1 or 2.

10. A vehicle tire comprising a rubber mixture according to claim 1 or 2 in at least one outer component, said outer component being the tread, the sidewall and / or the rim strip.

11. Use of a compound as defined in claim 1 or 2 as an ageing stabilizer in vehicle tires.

12. The following process steps: a) Formulas A) and B) 【Chemistry 3】 providing a compound of formula (I); b) reacting said compounds A) and B) with each other in the presence of a base and a catalyst to form a compound of formula C): 【Chemistry 4】 wherein the base is selected from the group consisting of potassium carbonate, potassium phosphate, sodium carbonate, sodium phosphate, cesium carbonate, sodium tert-butoxide, and potassium tert-butoxide, and the catalyst is a catalyst that catalyzes via copper coupling; c) reacting said compound of formula C) with hydrogen or a hydrogenation reagent and a ketone or aldehyde to form a compound of formula D): 【Chemistry 5】 obtaining a compound of formula (I); d) optionally reacting said compound of formula D) to form a compound of formula E): 【Chemistry 6】 obtaining a compound of formula (I); e) reacting said compound of formula D) or E) with an acid to obtain a compound of formula I): 【Chemistry 7】 The process of obtaining A method for preparing a compound of formula I comprising: In the formula, R １ teeth, xi) aromatic group, and xii) branched and cycloaliphatic C ４ ~C １２ basis, and xiii) an aromatic group and an aliphatic C １ ~C １２ Combination with groups wherein the group R ２ and R ３ may be the same or different, independently of one another, and may be linear, branched, or cyclic, saturated or unsaturated, aliphatic C １ ~C １２ and aryl groups, wherein n has a value of 0 or 1 or 2 or 3 or 4, and when n is 2 or 3 or 4, the group R ３ are, independently of one another, identical or different, In the formula, m takes the value 0 or 1 or 2 or 3, and when m is 2 or 3, the group R ２ are, independently of one another, identical or different; method.

13. 13. The process according to claim 12, characterized in that the reaction in step c) with hydrogen and the aldehyde or ketone is carried out using a hydrogenation catalyst and at a temperature of 120°C to 150°C, the reaction mixture is subjected to hydrogen at a pressure of 35 to 45 bar, and the reaction is carried out in an autoclave or in a separate pressure reactor.

14. Formula I): 【Chemistry 8】 [In the formula, R １ is a branched alkyl radical having 4 to 12 carbon atoms, In the formula, the group R ２ and R ３ are, independently of one another, the same or different, linear, branched and cyclic, saturated and unsaturated, aliphatic C groups optionally bearing one or more halogen substituents; １ ~C １２ groups, aryl groups optionally bearing one or more halogen substituents, and halogen groups, cyano groups, ester groups, ketone groups, ether groups, and thioether groups, wherein n takes the value 0; In the formula, m takes the value 0. Compound.

15. Formula II): 【Chemistry 9】 15. The compound of claim 14, characterized in that it has the structure:

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