Compounds, rubber blends containing the compounds, vehicle tires comprising at least one component of the rubber blends, processes for preparing the compounds, and use of the compounds as anti-aging and / or antioxidant agents

Abstract

The present invention relates to a compound, a rubber blend containing the compound, a vehicle tire comprising the rubber blend in at least one component, a process for preparing the compound, and the use of the compound as an antiaging agent and / or antioxidant. The compound according to the invention has the following formula (I): JPEG2025504011000026.jpg18170 (in the formula, R 1 xi) an aromatic group optionally having a substituent selected from the group consisting of a halogen group, a cyano group, an ester group, a ketone group, an ether group, and a thioether group, and xii) a linear, branched, and cyclic aliphatic C3-C 12 R 1 is optionally a divalent group attached to a monovalent benzene ring; and R 2 is a linear, branched and cyclic aliphatic C1-C cyclic alkyl group, optionally having one or more halogen substituents; 12 groups, optionally having one or more halogen substituents, aryl groups, and halogen groups, with fluorine, bromine and chlorine being preferred, cyano groups, ester groups, ketone groups, ether groups and thioether groups, and m has the value 0 or 1 or 2 or 3.

Description

[Technical field]

[0001] The present invention relates to the compounds, to rubber mixtures containing the compounds, to vehicle tyres comprising the rubber compound in at least one component, to a process for the manufacture of the compounds, and to the use of the compounds as ageing stabilizers and / or antioxidants. [Background technology]

[0002] Polymeric materials, particularly rubber, are known for use in vehicle tires and industrial rubber articles.

[0003] Natural rubber and synthetic polymers (e.g., IR, BR, SBR, ESBR, etc.), as well as natural and synthetic oils and lubricants, undergo oxidation reactions during long-term storage, especially in the intended applications, which are often subject to high temperatures, that adversely affect the originally desired properties. Depending on the type of polymer, the polymer chains shorten until the material liquefies or the material then hardens.

[0004] Thus, aging stabilizers contribute significantly to the service life of vehicle tires and other industrial rubber articles.

[0005] Known aging stabilizers include aromatic amines, e.g. 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine), IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine) or SPPD (N-(1-phenylethyl)-N'-phenyl-p-phenylenediamine) is included.

[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, thus scavenging them, thereby protecting the polymer from further oxidative reactions. Summary of the Invention [Problem to be solved by the invention]

[0007] However, a drawback of this substance class is that they may be carcinogenic.

[0008] Aging stabilizers that specifically react with ozone and result in its scavenging are also called "antiozonants."

[0009] A further problem associated with aging stabilizers is the undesirable blooming. Here, due to the rather poor solubility of the molecules of the aging stabilizer in the polymer matrix surrounding the rubber article, they diffuse to the surface of the article to be protected, causing the formation there of a film that is usually distinguishable in color from the rest of the article. In the case of vehicle tires, this is usually manifested as a brown coloration of the otherwise black sidewall. In addition to the aesthetic disadvantage, this is also associated with a disadvantage in terms of the aging stabilization effect. For this reason, the bloomed material is usually removed. This firstly reduces the total amount of aging stabilizer and also affects the diffusion of further molecules of aging stabilizer to its location, resulting in a lower level of protection of the polymer. [Means for solving the problem]

[0010] 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.

[0011] At the same time, the compound should be producible in a particularly energy- and cost-efficient manner.

[0012] 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 said compound, and by the vehicle tyre according to the invention which comprises in at least one component thereof the rubber mixture according to the invention.

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

[0014] The compound of claim 1 has the general formula I: [ka] (In the formula, R 1 xi) an aromatic group optionally having a substituent selected from the group consisting of a halogen group, a cyano group, an ester group, a ketone group, an ether group and a thioether group; and xii) linear, branched and cyclic aliphatic C3-C 12 R 1 is optionally a divalent group attached to a monovalent benzene ring; and R 2 is a linear, branched and cyclic aliphatic C1-C optionally having one or more halogen substituents; 12 groups, aryl groups optionally having one or more halogen substituents, and halogen groups, with fluorine, bromine and chlorine being preferred, cyano groups, ester groups, ketone groups, ether groups and thioether groups, and m is assumed to have the values ​​0 or 1 or 2 or 3.

[0015] When m is 0 (zero), 1, or 2, each hydrogen atom is represented by R 2 It will be apparent to one skilled in the art that, instead of being bound to the corresponding carbon atom of the benzene ring,

[0016] Similarly, (R 2 ) m and R 1 It will be clear to those skilled in the art that the representation of the HN bonds means that these groups can each be located at any position on the respective benzene ring, except of course for more than one being located at the same position at the same time, as already excluded by the tetravalency of the carbon atoms of the benzene ring.

[0017] In relation to the present invention, "C3-C 12 The reference to "a group" is understood to mean a group having 3 to 12 carbon atoms. Regardless, "C1" is used to represent the position of the most highly oxidized carbon atom / highest priority carbon atom according to the Cahn-Ingold-Prelog rule (CIP). What is meant in each case will be clear to those skilled in the art.

[0018] The compounds according to the invention are octahydroacridine derivatives and exhibit a lower potential hazard compared to known aniline-based aging stabilizers (possible cleavage products of 6PPD).

[0019] Compared to the known ageing stabilizer 6PPD, the compounds according to the invention show an equivalent reactivity towards oxygen, ozone or free radicals, so that the compounds of formula I) achieve an equivalent protective effect, in particular in vehicle tyres and other industrial rubber products, but also in oils and lubricants.

[0020] However, the present invention is not bound to any particular mechanism of action or to any particular explanation.

[0021] The compounds according to the invention are therefore suitable as replacements for 6PPD, the degradation products of which are highly toxic to chum salmon and therefore possibly also to other aquatic organisms.

[0022] The compound according to the present invention further has very good solubility in rubber mixtures, especially in vehicle tires and other industrial rubber articles.This means that the blooming of this compound, which often occurs with many aging stabilizers, is avoided, which means that the aging stabilization effect is advantageous / improved.The less the bloom of the aging stabilizer, the less the aging stabilizer is intentionally or unintentionally removed from the surface of the article to be protected, and as a result, the less the aging stabilizer diffuses to the surface.

[0023] Furthermore, the compounds according to the invention can be produced by the process according to the invention in a relatively simple and energy- and cost-efficient manner. In particular, the production does not require a precious metal catalyst. Moreover, the process can be carried out at room temperature. Moreover, the ionic liquid, which acts as both a solvent and a catalyst, can be reused after purification by extraction of the compounds according to the invention.

[0024] The compounds of formula I) according to the invention are particularly suitable as ageing stabilizers and / or antiozonants in vehicle tyres and / or other industrial rubber articles, such as, in particular, air springs, bellows, conveyor belts, straps, drive belts, hoses, rubber bands, profiles, seals, membranes, tactile sensors for medical or robotic use or shoe soles or parts thereof, and / or in oils and / or lubricants.

[0025] The compounds of formula I) according to the invention are particularly suitable for the manufacture of rubber articles, in particular air springs, bellows, conveyor belts, straps, drive belts, hoses, rubber bands, profiles, seals, membranes, tactile sensors for medical or robotic use or shoe soles or parts thereof.

[0026] For the use of the compounds of formula I) in the recited articles or materials, said compounds are used in compositions and are used incorporated into said compositions.

[0027] In vehicle tires or other industrial rubber articles, said composition is especially a rubber mix.

[0028] The present invention further provides the use of the compounds of formula I) according to the invention, in particular in fuels or oils and lubricants for fluid engines etc. In particular, the compounds according to the invention can be used in engines. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The present invention includes all the preferred embodiments as specifically 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 a preferred embodiment with a further feature described, for example, as "particularly preferred".

[0030] It is preferred that m in formula I) is zero.

[0031] The compound according to the present invention has the formula II: [ka] (In the formula, R 1 , R 2 and m is as defined above.

[0032] According to this preferred structure, the two nitrogen atoms are thus in the para position relative to each other.

[0033] wherein the compound has the formula IIa: [ka] (In the formula, R 1 It is particularly preferred when m is 0 (zero), so as to have the structure:

[0034] The compounds of formula II) and IIa) can be produced in a particularly simple and energy- and cost-efficient manner and, compared to 6PPD, show comparable reactivity towards oxygen, ozone or free radicals and therefore comparable ageing stabilization effectiveness.

[0035] base R 1 xi) an aromatic group optionally having a substituent selected from the group consisting of a halogen group, a cyano group, an ester group, a ketone group, an ether group, and a thioether group, and xii) a linear, branched, and cyclic aliphatic C3-C 12The group consisting of:

[0036] For both options xi) and xii) R 1 is optionally a divalent group attached to a monovalent benzene ring.

[0037] The aromatic groups of subgroup xi) are, for example, preferably selected from the phenyl group (-C6H5) and the benzyl group (-CH2-C6H5), with phenyl being particularly preferred.

[0038] The aromatic groups of subgroup xi) may optionally contain substituents.

[0039] As mentioned above, these are selected from the group consisting of halogen groups, cyano groups, ester groups, ketone groups, ether groups and thioether groups.

[0040] It is preferred if the substituents are selected from the group consisting of ester groups, ketone groups, ether groups and thioether groups.

[0041] In a preferred embodiment, the aromatic group is not substituted at the two carbon atoms adjacent to the C1 atom, i.e., the carbon atom bonded to the N atom. Therefore, 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.

[0042] In a further preferred embodiment, the aromatic groups of subgroup xi) are unsubstituted.

[0043] R 1 is preferably bonded to the nitrogen atom (N) via a tertiary carbon atom, i.e., the C1 atom is preferably a tertiary carbon atom.

[0044] In the context of the present invention, the term "tertiary carbon atom" is understood to mean a carbon atom which is bonded to only one hydrogen atom.

[0045] This results in particularly good solubility of the compounds of the invention in rubber mixtures, especially for vehicle tyres and other industrial rubber articles, and optimised reactivity with respect to mechanisms relating to ageing stabilisation.

[0046] In an advantageous embodiment, in particular in the above formulae I), II) and IIa), R 1 is a phenyl group.

[0047] In a particularly preferred embodiment, the compound according to the invention has formula III: [ka] It has the structure:

[0048] The compounds of formula III) have particularly good solubility in polymers, especially in rubber mixtures for vehicle tires and other industrial rubber articles. At the same time, they can be produced in a particularly simple, energy-efficient and cost-saving manner, and show the same reactivity to oxygen, ozone or free radicals compared to 6PPD, and therefore show the same aging stabilization effect.

[0049] According to the IPUAC nomenclature, the compound of formula III) is also called 6,9,9-trimethyl-N-phenyl-5,6,7,8,8a,9,10,10a-octahydroacridine-2-amine.

[0050] In a further advantageous embodiment, in particular in the above formulae I), II) and IIa), R 1 is a branched or cyclic alkyl group having 3 to 12 carbon atoms, preferably 3 to 8 carbon atoms, where R 1 is particularly preferably selected from the 1,3-dimethylbutyl and cyclohexyl radicals, where R 1 is very particularly preferably the 1,3-dimethylbutyl group.

[0051] This achieves particularly good solubility in rubber mixtures for vehicle tires and other industrial rubber articles.

[0052] In a further advantageous embodiment, R in formula I) 1 is a divalent group attached to a benzene ring having one valence.

[0053] Therefore, one valency of the benzene ring is R 1 Since m is occupied by , m can naturally only assume the values ​​0 or 1 or 2.

[0054] It is preferred if the divalent group is an aliphatic group.

[0055] As an example and particularly preferred, the compound has formula IV: [ka] (In the formula, R 2 where m is as defined above and m assumes the values ​​0, 1, or 2.

[0056] It is preferred if m in formula IV) assumes the value 0.

[0057] As mentioned above, the present invention comprises at least the following process steps: a1) Formula A1): [ka] providing a substance of b1) Formula B1): [ka] providing a substance of c1) reacting the substances of steps a1) and b1) in the presence of an ionic liquid, preferably 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM BF4), to obtain a compound of formula I): [ka] (In the formula, R 1xi) an aromatic group optionally having a substituent selected from the group consisting of a halogen group, a cyano group, an ester group, a ketone group, an ether group and a thioether group; and xii) linear, branched and cyclic aliphatic C3-C 12 R 1 is optionally a divalent group attached to a monovalent benzene ring; and R 2 is a linear, branched and cyclic aliphatic C1-C optionally having one or more halogen substituents; 12 groups, aryl groups optionally carrying one or more halogen substituents, and fluorine, bromine and chlorine are selected from the group consisting of halogen groups, cyano groups, ester groups, ketone groups, ether groups and thioether groups, and m is assumed to have the values ​​0 or 1 or 2 or 3; The present invention further provides a process for preparing a compound of formula I), comprising:

[0058] base R 1 and R 2 For and m, all of the previous embodiments described in connection with the description of the compounds according to the invention, including preferred embodiments, are applicable here as well.

[0059] It is preferred if the two nitrogen atoms of the substance of formula A1) are in the para position relative to each other.

[0060] For example, R 1 Materials of formula A1) where is phenyl are commercially available.

[0061] The substance of formula B1) is also known by the trivial name citronellal. As known to those skilled in the art, citronellal has two enantiomers, namely (R)-(+)-citronellal and (S)-(-)-citronellal, which can also exist as a racemate.

[0062] The reaction according to step c1) is based on the literature, see J.S. Adav, et al., Tetrahedron letters 46, (2005), 1039-1044, in which the improvements described below could also be identified.

[0063] As described in the literature, the product compound of formula I) is obtained in the process according to the invention as a 1:1 diastereomeric mixture, for example when the utilized substance of formula B1) is the enantiomer (R)-(+)-citronellal.

[0064] The reaction of step c1) is carried out in the presence of an ionic liquid.

[0065] Those skilled in the art are familiar with ionic liquids, which are salts that have relatively low melting points.

[0066] The ionic liquid is preferably used simultaneously as solvent and as catalyst.

[0067] It is preferable to use a hydrophilic ionic liquid. A person skilled in the art can distinguish between ionic liquids based on their hydrophobicity and can therefore select an appropriate hydrophilic ionic liquid.

[0068] The ionic liquid is preferably 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) or 1-methyl-3-octylimidazolium tetrafluoroborate (OMIMBF4), with 1-butyl-3-methylimidazolium tetrafluoroborate being particularly preferred.

[0069] It is preferred to utilize ionic liquids that are liquid at a temperature of 25°C, ie have a melting point below 26°C.

[0070] The reaction of step c1) is preferably carried out at room temperature, which means that the reaction medium does not need / is not heated by heat input from an external source, which makes the process according to the invention relatively energy efficient.

[0071] This is made possible in particular by the simultaneous selection of an ionic liquid with a correspondingly low melting point.

[0072] The reaction of step c1) is preferably carried out for at least 2 hours. The reaction mixture is therefore preferably stirred for at least 2 hours, particularly preferably for 2 to 12 hours, particularly preferably for 2 to 6 hours, particularly preferably for 2 to 4 hours.

[0073] It is also preferred to use 0.8 to 0.95 equivalents, particularly preferably 0.9 equivalents, of the substance of formula B1) per equivalent of the substance of formula A1).

[0074] This allows for complete reaction of the citronellal and therefore higher yields and purity of the product, while facilitating the reusability of the ionic liquid.

[0075] Step c1) followed by step d1): d1) an organic solvent, preferably a linear, branched or cyclic aliphatic C5-C 10 Extraction of the compound, particularly preferably with cyclohexane. It is preferable to carry out the following.

[0076] The extraction in step d1) is preferably carried out after contacting the reaction mixture after step c1) with a solvent by stirring for a period of 1 to 4 hours.

[0077] By extraction, the product, ie the compound of formula I) according to the invention, is removed from the ionic liquid.

[0078] In this specification, extraction refers to linear, branched or cyclic aliphatic C5-C 10 It has been found to be particularly advantageous to use a -compound, particularly preferably cyclohexane, which has the consequence that the excess reactant remains in the ionic liquid in the form of a compound of formula A1), which makes it possible to prepare the compounds according to the invention with particularly high product purity.

[0079] In this way, the ionic liquid is released from the reaction products by extraction, with only a portion of the reactants still remaining there.

[0080] For 1 equivalent of the substance of formula A1), 0.8 to 0.95 equivalents, particularly preferably 0.9 equivalents, of the substance of formula B1) are used, and after step c1), linear, branched or cyclic aliphatic C5-C 10 It is particularly advantageous to carry out the extraction with -compounds, in particular with cyclohexane.

[0081] This provides an ionic liquid which can be reused for further reactions according to steps a1) to c1) without further purification and thus in a particularly simple and energy-efficient manner.

[0082] It is preferred if d1) is further followed by purification of the solvent phase, preferably the cyclohexane phase, in particular by scrubbing, for example preferably with a saturated sodium chloride solution, followed by drying, for example preferably over sodium sulfate.

[0083] It is preferred if the solvent is then removed in a known manner, in particular under vacuum.

[0084] The process according to the invention therefore makes it possible to achieve a relatively simple, energy- and cost-efficient preparation of the compounds of formula I) according to the invention.

[0085] For example, R 1 To obtain compounds of formula I) where is 1,3-dimethylbutyl, the process can also be carried out analogously as shown in schemes XII) and XIII): [ka] (wherein MeOH represents methanol, H2 represents hydrogen, Pd represents palladium, and MIBK represents methyl isobutyl ketone, as known to those skilled in the art).

[0086] As mentioned above, BMIM*BF4 stands for 1-butyl-3-methylimidazolium tetrafluoroborate and is representative of the ionic liquid in the two schemes XII) and XIII).

[0087] All of the above embodiments herein apply with respect to each process step in which the reaction with citronellal is carried out in the presence of an ionic liquid.

[0088] In particular, each group R 1 If the starting material A1) containing is not commercially available, the analogous process steps shown are preferred.

[0089] As mentioned above, the present invention further provides a rubber mixture.

[0090] The rubber mixtures according to the invention contain, for example, compounds of formula I), preferably compounds of formula III). The rubber mixtures according to the invention may in principle be any rubber mixture in which, in particular, the novel compounds of formula I) according to the invention act as ageing stabilizers and / or antiozonants with low toxicity.

[0091] The rubber mixture according to the invention contains at least one rubber.

[0092] It is preferred if the rubber mixture according to the invention contains 0.1 to 10 phr, particularly preferably 0.1 to 7 phr, very particularly preferably 1 to 6 phr, next preferably 1 to 3 phr of compounds of the formula I), for example preferably compounds of the formula III).

[0093] The unit "phr" (parts per hundred parts by weight of rubber) used in this document is the customary designation of quantities for mixture formulations in the rubber industry. The dosages in parts by weight of individual substances are herein based on 100 parts by weight of the total mass of all high molecular weight (Mw > 20000 g / mol) rubbers present in the mixture.

[0094] In an advantageous embodiment of the invention, the inventive rubber mixture contains at least one diene rubber.

[0095] Thus, the rubber mixture may contain a diene rubber or a mixture of two or more different diene rubbers.

[0096] Diene rubbers are rubbers formed by the polymerization or copolymerization of dienes and / or cycloalkenes and therefore have C=C double bonds either in the backbone or in side groups.

[0097] 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 w is 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.

[0098] Nitrile rubber, hydrogenated acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, halobutyl rubber and / or ethylene-propylene-diene rubber are used in particular for the manufacture of industrial rubber articles such as straps, drive belts and hoses and / or shoe soles. Mixture compositions known to those skilled in the art for these rubbers, specific in terms of fillers, plasticizers, vulcanization systems and additives, are preferably used.

[0099] The natural and / or synthetic polyisoprene of all embodiments may 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.

[0100] Mixtures of one or more natural polyisoprenes with one or more synthetic polyisoprenes are further contemplated.

[0101] 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; Russian dandelion).

[0102] When the rubber mixture of the present invention contains butadiene rubber (i.e. BR, polybutadiene), it can 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.

[0103] The polybutadiene used may be end-modified with modifications and functionalizations and / or functionalized along the polymer chain. 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.

[0104] If at least one styrene-butadiene rubber (styrene-butadiene copolymer) is present in the rubber mixture, it may be a solution polymerized styrene-butadiene rubber (SSBR) and an emulsion polymerized styrene-butadiene rubber (ESBR), and it is also possible to utilize a mixture of at least one SSBR and at least one ESBR. The terms "styrene-butadiene rubber" and "styrene-butadiene copolymer" are used interchangeably in the context of the present invention.

[0105] 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.

[0106] 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.

[0107] 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).

[0108] In a particularly advantageous embodiment of the invention, the rubber mixture comprises at least one natural polyisoprene (NR) in an amount preferably between 50 and 100 phr, in one particularly advantageous embodiment of the invention in an amount between 80 and 100 phr, more preferably between 95 and 100 phr, then more preferably 100 phr. Such rubber mixtures exhibit optimized tear and wear properties combined with particularly good processability and reversion stability.

[0109] If the rubber mixture contains less than 100 phr of NR, it preferably contains as further rubber at least one diene rubber selected from the group consisting of synthetic polyisoprene (IR), butadiene rubber (BR), solution polymerized styrene-butadiene rubber (SSBR) and emulsion polymerized styrene-butadiene rubber (ESBR).

[0110] 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, in one particularly advantageous embodiment of the invention in an amount of 5 to 25 phr, more preferably in an amount of 5 to 20 phr. Such rubber mixtures exhibit particularly good processability and recovery stability, as well as optimized tear properties and optimal rolling resistance properties.

[0111] 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, more 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 properties of the rubber mixture according to the invention are achieved.

[0112] In a further particularly advantageous embodiment of the present invention, the rubber mixture comprises at least one solution polymerized styrene-butadiene rubber (SSBR), preferably in an amount of 10 to 80 phr, more preferably 30 to 80 phr, and in one particularly advantageous embodiment of the present invention in an amount of 50 to 70 phr. This achieves particularly good rolling resistance properties of the rubber mixture of the present invention. In a particularly advantageous embodiment of the present invention, the SSBR is used in combination with at least one further rubber in order to achieve an optimal and balanced property profile.

[0113] It is preferred if the rubber mixture contains at least one filler, preferably in an amount of 30 to 500 phr, more preferably 50 to 400 phr, then preferably in an amount of 80 to 300 phr.

[0114] 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.

[0115] 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.

[0116] It is preferred that the carbon black has an iodine number according to ASTM D1510, also known as iodine adsorption, of 30 to 250 g / kg, preferably 30 to 180 g / kg, more preferably 40 to 180 g / kg, and even more 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 more preferably 90 to 200 ml / 100 g.

[0117] The DBP value according to ASTM D2414 determines the specific absorption volume of dibutyl phthalate in carbon black or light colored fillers.

[0118] 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.

[0119] 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 blacks of the N339 type.

[0120] The silicon dioxide is preferably amorphous silicon dioxide, for example precipitated silica, also called precipitated silicon dioxide. However, it is also possible to use, for example, fumed silicon dioxide, instead.

[0121] However, 35 to 400 m 2 / g, preferably 35 to 350m 2 / g, more preferably 85 to 320 m 2 / g, and even more preferably 120 to 235 m 2 / g nitrogen surface area (BET surface area) (according to DIN ISO 9277 and DIN 66132) and 30-400 m 2 / g, preferably 30 to 330m 2 / g, more preferably 80 to 300m 2 / g, and even more preferably 115 to 200 m 2 It is particularly preferred to use finely divided precipitated silicas having a CTAB surface area (according to ASTM D 3765) of 10 ...

[0122] In a particularly advantageous embodiment of the invention, the rubber mixture contains, as filler, at least one silica, preferably in an amount of from 30 to 500 phr, more preferably from 50 to 400 phr, then preferably in an amount of from 80 to 300 phr.

[0123] 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).

[0124] In a further advantageous embodiment of the invention, the rubber mixture contains at least one silica as further filler, preferably in an amount of from 5 to 100 phr, more preferably from 5 to 80 phr, then preferably from 10 to 60 phr.

[0125] In these amounts, the silica is particularly present as an additional filler, especially in addition to other primary fillers such as carbon black.

[0126] The terms "silicic acid" and "silica" are used synonymously in connection with the present invention.

[0127] In a particularly advantageous embodiment of the invention, the rubber mixtures according to the invention contain from 0.1 to 60 phr, preferably from 3 to 40 phr, more preferably from 5 to 30 phr and even more preferably from 5 to 15 phr of at least one carbon black. In these amounts, the carbon black is present as a further filler, in particular in addition to the main fillers such as silica.

[0128] In a further advantageous embodiment of the invention, the rubber mixtures according to the invention contain from 30 to 300 phr, preferably from 30 to 200 phr and more 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.

[0129] In a particularly advantageous embodiment of the invention, the rubber mixture contains from 5 to 60 phr, more 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.

[0130] The rubber mixture may further contain further reinforcing or non-reinforcing fillers.

[0131] 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).

[0132] Further optional reinforcing fillers include, for example, carbon nanotubes (CNTs), such as discrete CNTs, hollow carbon fibers (HCFs) and modified CNTs containing one or more functional groups, such as hydroxy, carboxy and carbonyl groups, graphite and graphene, and what are known as "carbon-silica dual phase fillers."

[0133] In the context of the present invention, zinc oxide is not included in the filler.

[0134] 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.

[0135] 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.

[0136] In a particularly advantageous embodiment, the rubber mixture according to the invention does not contain, in addition to the inventive compound of formula I), any ageing stabilizer 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).

[0137] With very small amounts of p-phenylenediamine, preferably 0-0.1 phr, more preferably 0 phr, and the compounds of formula I) present according to the invention, it is possible to achieve the same protective effect with lower toxicity, where the compounds of formula I) of the invention are a replacement for the aforementioned p-phenylenediamines known in the art.

[0138] In a further advantageous embodiment of the present invention, since at least one further representative of the mentioned p-phenylenediamine aging stabilizers is present, the compounds of the present invention only partially replace the p-phenylenediamines known in the prior art, which also achieves the advantages of the present invention, but only to a less than optimal extent.

[0139] 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.

[0140] 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.

[0141] The silane coupling agent may be of any type known to those skilled in the art.

[0142] Furthermore, 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.

[0143] 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.

[0144] 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).

[0145] Usable silane coupling agents are thus, 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).

[0146] 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 / 083241 A1, WO 2008 / 083242 A1, WO 2008 / 083243 A1 and WO 2008 / 083244 A1. Usable silanes include, for example, 3-octanoylthio-1-propyltriethoxysilane, sold in many varieties by Momentive in the USA under the name NXT, or sold by Evonik Industries under the name VPSi363®.

[0147] 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.

[0148] Zinc oxide (ZnO) may be included in the overall proportion of further additives in the amounts mentioned above.

[0149] This may be any type of zinc oxide known to those skilled in the art, for example ZnO granules or powder. The zinc oxides normally used generally have a BET surface area of ​​less than 10 m2 / g. However, it is possible to obtain a surface area of ​​between 10 and 100 m2. 2It is also possible to use zinc oxide having a BET surface area of ​​100 nm / g, for example "nano zinc oxide".

[0150] The rubber mixtures of the invention are preferably used in vulcanized form, in particular in vehicle tyres or other vulcanization technical rubber articles.

[0151] The terms "vulcanization" and "crosslinking" are used synonymously in the context of the present invention.

[0152] The vulcanization of the rubber mixtures 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 accelerators, mercapto accelerators, sulfenamide accelerators, thiocarbamate accelerators, thiuram accelerators, thiophosphate accelerators, thiourea accelerators, xanthogenate accelerators and guanidine accelerators.

[0153] N-cyclohexyl-2-benzothiazolylsulfenamide (CBS), It is preferred to use a sulfenamide accelerator selected from N,N-dicyclohexylbenzothiazole-2-sulfenamide (DCBS), benzothiazyl-2-sulfene morpholide (MBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and guanidine accelerators such as diphenylguanidine (DPG).

[0154] The sulfur donor material used can be any sulfur donor material known to those skilled in the art.

[0155] Vulcanization retarders may also be present in the rubber mixture.

[0156] The preparation of the rubber mixture of the present invention is preferably carried out by the process conventional in the rubber industry, in which a primary mixture containing all the components except the vulcanization system (e.g. sulfur and vulcanization-affecting substances) is first prepared in one or more mixing stages. The final mixture is produced by adding the vulcanization system in the final mixing stage.

[0157] The final mixture may be further processed and formed into a suitable shape, for example, by an extrusion operation or by calendering.

[0158] The rubber mixture of the present invention is particularly suitable for use in vehicle tires, especially pneumatic vehicle tires.In principle, it is possible to use it in all tire components, especially in the outer components, especially preferably in the flange profile, the tread and / or the sidewall.In the case of a tread having a cap / base structure, it is preferred that the rubber mixture of the present invention is used at least in the cap.

[0159] 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.

[0160] The production of the rubber mixture of the invention for use as any other body mix in vehicle tires is carried out as described above. The difference lies in the shaping after the extrusion / calendering operation of the mixture. The shape of the rubber mixture thus obtained, not yet vulcanized, for one or more different body mixes is then subjected to the production of green tires.

[0161] 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.

[0162] The green tire, which has not yet been cured, is then cured.

[0163] For the use of the rubber mixture of the invention in drive belts and other belts, in particular 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 several plies of the rubber mixture, one and / or several plies of identical and / or different reinforcing elements and one and / or several further plies of the same and / or other rubber mixtures.

[0164] 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.

[0165] 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.

[0166] In the context of this invention, "vehicle tires" means pneumatic vehicle tires and solid rubber tires, including industrial tires, as well as tires for construction vehicles, trucks, cars and motorcycles.

[0167] 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.

[0168] The vehicle tyre according to the invention may therefore comprise a rubber mixture according to the invention comprising an inventive compound of formula I) in two or more components, optionally with a compatible composition. EXAMPLES

[0169] The present invention will be described in detail with reference to the following examples.

[0170] Compounds of formula III) as exemplary embodiments of compounds of formula I) were prepared in the manner shown in scheme X1) below: [ka]

[0171] For this purpose, 5.00 g of N-phenyl-p-phenylenediamine (27.1 mmol, 1 equivalent (eq.)) and 3.76 g of (R)-citronellal (24.4 mmol, 0.9 eq.) were mixed with 25 ml of BMIMBF4 and stirred overnight at room temperature (RT). Afterwards, 100 ml of cyclohexane were added and the mixture was stirred for another hour. The cyclohexane phase was separated, washed with saturated sodium chloride solution and dried over sodium sulfate (Na2SO4). After removing the organic salts by filtration, the solvent was removed under vacuum. Brown to black viscous oil; yield 7.74 g (99% of theory).

[0172] The product may be, for example, 1 H-NMR and 13 As evidenced by the C-NMR data, it was obtained here as a 1:1 diastereomeric mixture. 1 H-NMR (“Nuclear Magnetic Resonance”) (500MHz,DMSO-d6)δ=7.43(s,1H),7.39(s,1H),7.12-7.03(m,4H),6.93(d,J=2.4Hz,1H),6.83(d, J=2.4Hz,1H),6.76(ddd,J=8.3,7.1,1.3Hz,4H),6.70(dd,J=8.4,2.3Hz,2H),6.61-6.53(m,2H),6.43(dd,J=10.5,8 .4Hz,2H),5.33(s,2H),3.70(q,J=3.1Hz,1H),2.96(td,J=10.2,4.1Hz,1H),1.95(dd,J=12.3,2.1Hz,1H),1.88-1.7 1(m,3H),1.68-1.45(m,4H),1.40(s,2H),1.23(d,J=8.2Hz,6H),1.19-1.11(m,6H),1.03(s,3H),0.99-0.83(m,9H). 13C-NMR(126MHz,DMSO)δ=147.6,147.5,139.9,131.3,131.0,130.8,129.4,129.4,128.0,121.0,121.0,120.6,120.4,117.2,117.0,1 14.3,113.8,113.7,50.4,47.3,46.5,44.3,43.2,35.7,35.3,35.0,34.7,30.8,27.8,27.3,26.8,26.5,26.0,25.5,24.8,23.2,22.7. ESI-MS (electrospray ionization mass spectrometry) [M+H] + =321.

[0173] Measurement of oxidative induction time (OIT) The compound of formula III) was studied under laboratory conditions with regard to its potential protective effect as an ageing stabilizer by measuring the oxidation induction time.

[0174] For this purpose, the compound of formula III and 6-PPD were 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).

[0175] The specimens were maintained at isothermal conditions of 180° C. under N2 atmosphere, and then the atmosphere was switched to O2 atmosphere (volume flow rate 50 ml / min).

[0176] DSC (differential scanning calorimetry) was used to determine the oxidation via peaks.

[0177] The time (min) until oxidation was measured.

[0178] The results compared with the known aging stabilizer 6-PPD are summarized in Table 1.

[0179] [Table 1]

[0180] Considering the measurement accuracy of ±(plus / minus) 10 minutes, it is clear that the compound of formula III) achieves a protective effect comparable to that of 6PPD.

[0181] The inventive compounds of the formula III), as representatives of the inventive compounds of the formula I), are therefore more environmentally friendly and less harmful to health than 6-PPD / further representatives of the substance class as mentioned above, and are also comparable ageing stabilizers.

[0182] At the same time, the inventive compounds of the formula III), as representatives of the inventive compounds of the formula I), show very good solubility in rubber mixtures, which prevents blooming and thus improves the protective effect.

[0183] The compounds of formula I) therefore make it possible to achieve, for the possible applications described, a comparable or even improved protective effect in terms of reduced blooming behavior.

[0184] Two further compounds of the invention are disclosed, namely, 3,14,14-trimethyl-2,3,4,4a,5,12,14,14a-octahydroquinolino[2,3-b]acridin-7(1H)-one (divalent R 1 and Formula IIa) with m=0, and 3,7,7,10,14,14-hexamethyl-1,2,3,4,4a,5,7,7a,8,9,10,11,11a,12,14,14a-hexadecahydroquinolino[2,3-b]acridine (Formula IV), (m=0) were prepared according to the following synthetic procedure.

[0185] Synthesis of 3,14,14-trimethyl-2,3,4,4a,5,12,14,14a-octahydroquinolino[2,3-b]acridin-7(1H)-one: [ka] Under argon atmosphere, 5.50 g (26.2 mmol, 1 eq) of 2-aminoacridin-9(10H)one was dissolved in 200 ml of dry acetonitrile and 4.25 ml (23.5 mmol, 0.9 eq) of citronellal was added. Then 33 μl (0.26 mmol, 0.1 eq) of boron trifluoride etherate was added dropwise and the mixture was stirred overnight. After the reaction was completed, the reaction mixture was poured onto ice and extracted with dichloromethane. The resulting solid (representative product) was removed by filtration. The mother liquor was washed with saturated sodium chloride solution, dried over sodium sulfate and the sodium sulfate was removed by filtration. The solvent was then evaporated and the product was purified by column chromatography (cyclohexane / acetic ester; 4:1). Orange solid; yield 6.30 g (70% of theory).

[0186] Due to the presence of diastereomers, two sets of signals are obtained, but this does not affect the purity of the compound and its mode of action (purity test by LC-MS / UV-VIS). The molecule of the present invention is utilized as a mixture of both diastereomers. The H-NMR data of the two individual diastereomers, which can be separated by column chromatography, are reported below. 1 H-NMR(500MHz,DMSO-d6)δ=11.11(s,1H),8.06(dd,J=8.1,1.4Hz,1H),7.53(ddd,J=8.4,6.9,1.6Hz,1 H),7.35(dt,J=8.4,0.8Hz,1H),7.13(d,J=8.9Hz,1H),7.09-7.03(m,2H),5.59(s,1H),3.80(d,J=3.2 Hz,1H),1.87(dt,J=13.6,2.9Hz,1H),1.76(s,3H),1.59-1.52(m,1H),1.47-1.42(m,1H),1.40(s,3H) ,1.20-1.11(m,3H),0.87(d,J=6.5Hz,3H),0.81(dd,J=12.2,3.0Hz,1H),0.72(qd,J=12.8,3.3Hz,1H). 1H-NMR(500MHz,DMSO-d6)δ=11.20(s,1H),8.12(dd,J=8.1,1.5Hz,1H),7.55(ddd,J=8.3,6.8,1.5Hz,1H),7.4 0-7.35(m,1H),7.18(d,J=8.9Hz,1H),7.09(ddd,J=8.1,6.9,1.1Hz,1H),7.01(d,J=8.8Hz,1H),5.56(d,J=1.4 Hz,1H),3.04(dddt,J=10.6,8.6,4.3,2.1Hz,1H),2.02(s,1H),1.84(dp,J=12.8,2.9Hz,1H),1.80-1.72(m,1H ),1.64(s,3H),1.52(dddd,J=15.8,12.6,6.8,1.4Hz,1H),1.42(s,3H),1.29-1.22(m,1H),1.00-0.83(m,6H). ESI-MS [M+H] + =347.

[0187] Synthesis of 3,7,7,10,14,14-hexamethyl-1,2,3,4,4a,5,7,7a,8,9,10,11,11a,12,14,14a-hexadecahydroquinolino[2,3-b]acridine: [ka] Under argon atmosphere, 3 g (27.7 mmol, 1.0 eq) of p-phenylenediamine were dissolved in 60 ml of dry acetonitrile and 10.07 ml (55.5 mmol, 2.0 eq) of citronellal were added. Then 70 μl (0.5 mmol, 0.02 eq) of boron trifluoride etherate were added dropwise and the mixture was stirred for 5 hours. After the reaction was over, the reaction mixture was poured onto ice and extracted with dichloromethane. The organic phase was washed with saturated sodium chloride solution, dried over sodium sulfate and the sodium sulfate was removed by filtration. The solvent was then removed. Brownish-red solid; yield 10 g (95% of theory).

[0188] The resulting mixture was used without further purification and consisted of the 1:1 and 3:1 reaction products of citronellal with p-phenylenediamine, as well as the desired target compound present as a diastereomeric mixture (see Table 2). These molecules also act as aging stabilizers.

[0189] [Table 2]

[0190] For use in rubber mixtures for vehicle tyres, the compounds of the invention of formula I), for example the substances of formula III), 3,14,14-trimethyl-2,3,4,4a,5,12,14,14a-octahydroquinolino[2,3-b]acridin-7(1H)-one or 3,7,7,10,14,14-hexamethyl-1,2,3,4,4a,5,7,7a,8,9,10,11,11a,12,14,14a-hexadecahydroquinolino[2,3-b]acridine, are added in a manner known to those skilled in the art in one of the mixing stages during the preparation of the rubber mixture, instead of ageing stabilizers known from the prior art, such as, for example, 6PPD, 7PPD or IPPD.

[0191] For this purpose, the compound of formula III) (= substance A), 3,14,14-trimethyl-2,3,4,4a,5,12,14,14a-octahydroquinolino[2,3-b]acridin-7(1H)-one (= substance B) or 3,7,7,10,14,14-hexamethyl-1,2,3,4,4a,5,7,7a,8,9,10,11,11a,12,14,14a-hexadecahydroquinolino[2,3-b]acridin (= substance C) are mixed in different amounts, for example as shown in table 3. The obtained examples of the invention are labelled E.

[0192] For comparison, rubber mixtures containing 6PPD instead of the aforementioned compounds are utilized as aging stabilizers, substituting in each case on a mole / mole basis between V1 and E1-E3, and between V2 and E4-E5, with otherwise identical compositions. The amounts in Table 2 are reported in phr. A reference (Ref.) without aging stabilizer is also reported.

[0193] In all mixtures the sum of the amounts of ageing stabilizer (6PPD or substance of the invention) and plasticizer oil MES is 10 phr.

[0194] [Table 3]

[0195] All the mixtures in Table 3 were used to prepare test specimens by vulcanization at 160°C under pressure for 20 minutes, and these test specimens were used to measure material properties typical of the rubber industry, using the test methods specified below, before and after aging the test specimens in air at 70°C for 28 days. - Shore A hardness at room temperature according to DIN ISO 7619-1 durometer - Resilience at room temperature according to ISO4662 - Stress values ​​at 100% elongation at room temperature according to DIN 53504 - Elongation at break at room temperature according to DIN 53504

[0196] The measured values ​​are shown in Table 4.

[0197] [Table 4]

[0198] As is evident from Table 4, the mix properties before aging are at a comparable level for all mixes. However, after aging, it was found that the mixes containing the compound of the invention have a better elongation at break than the mixes containing 6-PPD. The mixes of the invention therefore show an improved protection effect against aging compared to 6-PPD. They are also more environmentally friendly and less harmful to health than 6-PPD or other representative substances, and have a very good solubility in rubber mixes. Blooming is avoided and the protection effect is improved.

Claims

1. Formula I): 【Chemical 1】 (In the formula, R １ xi) an aromatic group optionally having a substituent which is a ketone group; and xii) cyclic aliphatic C ３ ~C １２ is selected from the group consisting of For both xi) and xii) above, R １ is optionally a divalent group attached to the benzene ring in the formula with one valence; and R ２ is a linear, branched and cyclic aliphatic C optionally having one or more halogen substituents; １ ~C １２ a group selected from the group consisting of an aryl group optionally having one or more halogen substituents, a halogen group, a cyano group, an ester group, a ketone group, an ether group and a thioether group, and m is the value 0.

2. Formula II): 【Chemistry 2】 (In the formula, R １ , R ２ and m is as defined for claim 1.

3. When m is 0 (zero), the compound therefore has the formula IIa: 【Chemistry 3】 (In the formula, R １ The compound according to claim 2, characterized in that it has the structure:

4. R １ The compound according to any one of claims 1 to 3, characterized in that is bonded to the nitrogen atom (N) via a tertiary carbon atom.

5. R １ The compound according to any one of claims 1 to 3, characterized in that is a phenyl group.

6. Formula III) 【Chemistry 4】 The compound according to any one of claims 1 to 3, characterized in that it has the structure:

7. The following formula 【Chemistry 5】 The compound according to any one of claims 1 to 3, characterized in that it has the structure:

8. R １ 3. The compound according to claim 1, wherein is a divalent group attached with one valence to the benzene ring in said formula.

9. The compound of claim 8, wherein the divalent group is aliphatic.

10. The compound has the formula IV: 【Chemistry 6】 (In the formula, R ２ is as defined for claim 1 and m is the value 0.

11. A rubber mixture containing a compound according to any one of claims 1 to 3.

12. A rubber mixture containing a compound according to any one of claims 1 to 3, said rubber mixture comprising at least one diene rubber.

13. A vehicle tire comprising in at least one component the rubber mixture according to claim 11.

14. A vehicle tire comprising in at least one outer component a rubber mixture as defined in claim 11, said outer component being a tread, a sidewall and / or a flange profile.

15. Use of the compounds according to any one of claims 1 to 3 as ageing stabilizers and / or antiozonants.

16. Use of a compound according to any one of claims 1 to 3 as an ageing stabilizer and / or antiozonant in vehicle tyres, other industrial rubber articles, oils and / or lubricants.

17. Use of a compound according to any one of claims 1 to 3 for the manufacture of rubber articles.

18. Use of the compounds according to any one of claims 1 to 3 in oils and lubricants.

19. The method steps are as follows: a1) Formula A1): 【Chemistry 7】 providing a substance of b1) Formula B1): 【Chemistry 8】 providing a substance of c1) reacting the materials of steps a1) and b1) in the presence of an ionic liquid to form a compound of formula I): 【Chemistry 9】 (In the formula, R １ xi) an aromatic group optionally having a substituent which is a ketone group; and xii) cyclic aliphatic C ３ ~C １２ groups, and for both xi) and xii), R １ is optionally a divalent group attached to the benzene ring in the formula with one valence; and R ２ is a linear, branched and cyclic aliphatic C optionally having one or more halogen substituents; １ ~C １２ a group selected from the group consisting of an aryl group optionally having one or more halogen substituents, a halogen group, a cyano group, an ester group, a ketone group, an ether group and a thioether group, and m is the value 0; A method for preparing a compound of formula I, comprising:

20. Step c1) followed by step d1): d1) Extracting with an organic solvent 20. The method of claim 19, followed by

21. 21. The method according to claim 19 or 20, characterized in that 0.8 to 0.95 equivalents of the substance of formula B1) are used per equivalent of the substance of formula A1).

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