Stable rubber composition providing protection against ozone

Abstract

A rubber composition having good resistance to ozonization properties, in particular without the need to use 6PPD. This rubber composition is suitable for use in rubber articles, including in particular vehicle tires, such as rubber pneumatic tires, solid tires and non-pneumatic tires, and also general rubber products exposed to continuous and intermittent dynamic operating conditions and requiring protection from ozonization, like belts, hoses, cables, automotive mountings and bushings. In the rubber composition, the anti-ozonant compound is a partially hydrogenated quinoline derivative having formula (I) and serves to protect the rubber composition from ozonization and the consequent damaging effects caused by ozonization on the rubber composition.

Description

Technical Field

[0001] The present invention, as described herein, relates to rubber compositions, and more particularly to tire rubber compositions exhibiting good ozone resistance, and especially good ozone resistance without the use of 6PPD. The rubber compositions according to the invention are particularly suitable for rubber articles, including, in addition to seals and gaskets, especially vehicle tires (such as pneumatic rubber tires, solid tires, and non-pneumatic tires), as well as general rubber products (such as belts, hoses, cables, automotive fittings, and bushings) exposed to continuous and intermittent dynamic operating conditions and requiring protection against ozone. The invention also relates to the use of ozone-resistant compounds, as defined below, for protecting rubber compositions from ozone and the resulting damaging effects on the rubber compositions caused by ozone. Background Technology

[0002] Tires (such as vehicle tires) and other articles made of rubber are manufactured from rubber compositions that contain rubber (such as natural rubber, synthetic rubber, or combinations thereof), reinforcing fillers, vulcanizing agents, and other components that improve the physical and mechanical properties of both the uncured and cured rubber compositions.

[0003] Natural rubber and synthetic polymers (such as IR, BR, SSBR, ESBR, etc.), as well as natural and synthetic oils, fats, and lubricants, undergo oxidation reactions during long-term storage and during the use phase, which often involves exposure to elevated temperatures in the target application. These oxidation reactions adversely affect the original desired properties. Depending on the type of polymer, the polymer chains are shortened until the material liquefies, or the crosslinking density of the material increases. Both processes are undesirable and need to be prevented to ensure long-term consistency of material properties.

[0004] Therefore, anti-aging agents (like antioxidants and anti-ozone agents) significantly contribute to the lifespan of vehicle tires and other industrial rubber products. They can react with ozone and deactivate free radicals (such as alkyl radicals, hydroxyl radicals, hydroperoxy radicals, and alkylperoxy radicals), thus protecting rubber from degradation reactions.

[0005] Anti-aging agents that specifically react with ozone and can protect rubber from the harmful effects of ozone are also known as "antiozonant agents" or "antiozonants".

[0006] If rubber products based on highly unsaturated elastomers remain unprotected, ozone present in the environment will corrode the surface of the rubber material. This ozone corrosion will cause cracks on the rubber surface, especially if the rubber is under strain during use. These initial cracks can further develop into deep and large cracks, particularly when the rubber product is subjected to dynamic loading conditions. Such deep and large cracks can not only shorten the service life of rubber products such as tires, but may also eventually lead to mechanical failure in extreme cases, thus causing safety problems in the use of rubber products.

[0007] Different standards such as DIN, ISO, VDE, SAE, and ASTM describe static methods (“static ozone cracking tests”) and dynamic methods (“dynamic ozone cracking tests”) for studying the behavior of rubber samples to ozone. Typically, the rubber sample is stretched and ozone is applied under defined temperature, humidity, and air velocity conditions. A normalized crack index can be calculated when the surface ozone cracking of a “comparative rubber compound part” is graded. For dynamic ozone cracking tests, the sample is also subjected to cyclic strain in an ozone chamber. To combat ozone attack on rubber, various anti-ozone agents have been developed and commercialized to slow the formation of ozone cracks under both static and dynamic conditions. For example, waxes with various properties have been developed and applied to rubber to resist static ozone erosion by forming a film barrier on the surface. However, this film will break down under dynamic conditions and lose its ozone-protective properties.

[0008] For dynamic protection, various chemical anti-ozone agents have been developed and are commercially available. One well-known and widely used group is substituted phenyl-p-phenylenediamine (PPD), with 6PPD (N-1,3-dimethylbutyl-N'-phenyl-p-phenylenediamine [CAS No.: 793-24-8]) being one of the most popular representatives. The PPD "family" further includes, for example, IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine), 7PPD (N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine), 77PD (N,N'-bis(1,4-dimethylpentyl)-p-phenylenediamine), 44PD (N,N'-disec-butyl-p-phenylenediamine), and 8PPD (N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine).

[0009] The PPD group may also include derivatives such as N-cyclohexyl-N'-phenyl-p-phenylenediamine (CHPPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-xylyl-p-phenylenediamine (DTPD) or SPPD (N-(1-phenylethyl)-N'-phenyl-p-phenylenediamine).

[0010] Another group of chemicals based on PPD chemical composition, selected from quinones (Q), quinone imines (QI), and quinone diamines (QDI), has been reported in rubber compounds.

[0011] US 6,533,859 discloses a method for pretreating the surface of carbon black with such chemicals to improve the dispersibility of carbon black and the dynamic properties of rubber formulations.

[0012] EP 1025155 teaches a method for improving the processability of uncured rubber by high-temperature mixing of quinone diamine, natural rubber and carbon black.

[0013] US 8,207,247 teaches a method for mixing a rubber composition comprising natural rubber and an additive selected from the above-mentioned chemicals (preferably quinone diamine).

[0014] Recently, WO 2022 / 069001 disclosed phenothiazine compounds and their use as anti-ozone agents in rubber blends and vehicle tires.

[0015] Furthermore, WO 2022 / 146441 discusses rubber compositions with improved ozone resistance, which contain hydroxylated PPDs particularly suitable for rubber articles such as tires.

[0016] PPD is known to also act as a primary and secondary antioxidant by scavenging free radicals and converting hydroperoxides into less harmful intermediates.

[0017] Some anti-aging agents (such as IPPD) are poorly soluble in rubber and therefore migrate to the surface, forming a colored film. This effect is known by the name "blooming," which means that the anti-aging agent "blooms" from the corresponding rubber.

[0018] During the service life of rubber compositions containing PPD-type antiozone agents, these antiozone agents typically (with some exceptions) migrate to surfaces, reacting with ozone in the environment and providing ozone protection (as in the case of tire sidewalls and treads). Therefore, the load of the antiozone agent and its migration rate to the surface limit the service life of the rubber article. Clearly, the better and faster the migration to the surface, the better the initial protection. On the other hand, the fixed load and “uncontrolled” nature of antiozone agents mean that excessively rapid migration to the surface not only negatively impacts long-term protection but also leads to surface leaching and / or volatilization, causing the article to “stain” due to excessive surface concentration. Furthermore, PPDs are prone to discoloration, which exacerbates the visual effects of migration and staining. For example, if a staining antiozone agent is used in a black rubber composition near a light-colored rubber part, the staining antiozone agent will migrate into the light-colored rubber part and cause discoloration, representing another problem with PPDs that needs to be addressed.

[0019] To date, various types of compounds and solutions have been evaluated in this regard.

[0020] For example, US 5,047,530 teaches the preparation and use of larger molecules (substituted triazines) for more durable and non-staining ozone protection. However, the molecule itself is prone to discoloration and is therefore unsuitable for use in light-colored rubber compositions.

[0021] Another group of chemicals (hindered phenols, such as 2,2'-methylenebis(4-methyl-6-tert-butylphenol)) are frequently used as antioxidants in rubber compositions, even though they obviously do not provide protection against ozone attack. Because these hindered phenols are generally non-dyed, they are often blended into light-colored products where dyeing should be minimized, such as the white sidewalls and colored treads in tires.

[0022] However, these hindered phenols are highly effective antioxidants, but typically have limited effectiveness in protecting rubber compositions from ozone degradation.

[0023] Generally speaking, it can be said that compounds exhibiting excellent antioxidant properties do not necessarily provide protection against ozone. Therefore, it is impossible to predict the correlation between high antioxidant efficiency and related ozone-resistant properties.

[0024] Literature confirms that antioxidants that can be used to extend the life of rubber products under bending conditions do not necessarily function as ozone inhibitors, meaning they do not necessarily provide any protection against the destructive effects of ozone on rubber.

[0025] For example, it was clearly acknowledged decades ago that the relationship between ozone cracking and flexural cracking is a source of some confusion, as conditions of high-velocity dynamic weathering exposure also contribute to flexural cracking. Antioxidants that effectively extend flexural life may or may not exhibit anti-ozone activity. For example, both N-phenyl-2-naphthylamine and N-isopropyl-N'-phenyl-p-phenylenediamine have anti-flexural-cracking activity, however only the latter is an anti-ozone agent, while the former is not (J. CAMELEANG et al., Rubber Chemistry and Technology, 36(4), 1963, 1497-1591, p. 1518).

[0026] As is well known, aromatic amines generally have undesirable toxicological properties, as many representatives of this class of chemicals are known to be harmful to human and animal health as well as to aquatic life.

[0027] In particular, the continued use of ozone-resistant agents in recognized PPD categories is becoming increasingly critical. The ECHA registration file states that "based on the available degradation information, all PPDs discussed are not readily biodegradable and no apparent biodegradation has been observed, but complete non-biodegradation has occurred."

[0028] A possible explanation for this non-biodegradability is the following hypothesis: 6PPD itself, and possibly 6PPD quinone (one of its degradation products), is highly toxic to bacteria. In biodegradation tests of 6PPD, even low concentrations can have a significant effect, killing bacteria or at least inhibiting bacterial growth. In the atmosphere, rapid photodegradation occurs through reaction with photochemically generated OH radicals. According to ECHA's registration file, regarding environmental and monitoring data, 6PPD has been used as an indicator for other members of the PPD family, as it is commonly used in tire production.

[0029] A recent study (Tian et al., Science 371, 185-189 (2021) "A ubiquitoustire rubber-derived chemical induces acute mortality in coho salmon") found that in the Pacific Northwest of the United States, annual exposure to rainwater caused unexplained acute mortality in coho salmon (Oncorhynchus kisutch) as adult salmon migrated to urban creeks to breed resulted in death. A highly toxic quinone transformation product of N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine (6PPD) was discovered. A retrospective analysis of representative riparian streams and rainwater-affected creeks along the US West Coast revealed widespread presence of toxic concentrations of 6PPD quinone. These results not only reveal the unexpected risks of 6PPD to aquatic species but also highlight the toxicological relevance of dissipating tire rubber residues.

[0030] These findings clearly demonstrate the need to identify suitable alternative compounds for PPD so that they can be safely used as anti-ozone agents in rubber products, including tires. This could help reduce or even eliminate the demand for 6PPD and other PPDs. Furthermore, these alternative solutions are preferably less prone to discoloration than PPDs, which would help increase customer acceptance and broaden the application range of such alternative solutions.

[0031] The demand for durable rubber products that retain their original color, remain safe and reliable throughout their entire service life, and simultaneously reduce the release of toxic substances into the environment remains unresolved. This need is addressed by the rubber composition products of the present invention. Summary of the Invention

[0032] The object of this invention is to provide anti-aging, especially anti-ozone, compounds that can be used, in particular, as anti-aging agents in vehicle tires or other industrial rubber products, to achieve a protective effect on these products and thereby replace or reduce the presence of PPD, especially 6PPD.

[0033] This objective is achieved by using a partially hydrogenated quinoline derivative (also referred to below as "hydroquinoline derivative" or "compound according to the invention") as defined below.

[0034] The anti-ozone agent "the compound according to the present invention" has the following formula (I):

[0035] (I)

[0036] in

[0037] X is selected from N or the CA group, where

[0038] At least one of X is N, but no more than two of X are N; and

[0039] in

[0040] A is H, CN, or an electron-donating group, and this electron-donating group is...

[0041] Directly bonded to the oxygen or nitrogen atom of the aromatic ring; or

[0042] It is aryl or C1-C 20 -alkyl, C1-C 20 -Alkenyl or C1-C 20 -alkoxy group;

[0043] and

[0044] R 1 R 1’ R 2 R 2’ Each of them independently chooses from the following groups: hydrogen, C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl, and wherein

[0045] R 1 or R 1’ One of them and R 2 or R 2' One of them can optionally form a double bond together;

[0046] and

[0047] R 3 R 3’ Selected independently from C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl.

[0048] The compounds of formula (I) of the present invention are hydrogenated quinoline derivatives, and more specifically, partially hydrogenated quinoline derivatives.

[0049] Such partially hydrogenated quinoline derivatives have been described in WO 2017 / 040961, wherein they are included in lubricant compositions which further comprise a base oil in an amount greater than 70% by weight of the lubricant composition.

[0050] Based on quantitative structure-activity relationship (QSAR) models (according to ECHA, these models are considered to provide reasonable predictions of the environmental fate of compounds based on knowledge of their chemical structure), the quinoline derivatives used below as antioxidants and anti-ozone agents according to the present invention are expected to be less harmful to the environment and human and animal health, for example implying lower aquatic toxicity and lower skin sensitization potential, compared to classic aromatic amines used for this purpose (such as 6PPD or IPPD).

[0051] Furthermore, the object of this invention is to obtain hydrogen quinoline derivatives having formula (I) by a method for producing partially hydrogenated quinoline derivatives. Additionally, protection is claimed for their use as anti-aging agents and / or antioxidants and / or anti-ozone agents.

[0052] Another object of the present invention is to provide a rubber composition comprising one or more partially hydrogenated quinoline derivatives as defined below.

[0053] Embodiments of the present invention can be used in finished rubber products including non-pneumatic tires, solid tires, pneumatic tires, and tire components. Aspects and advantages of the invention will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practicing the invention.

[0054] Specific embodiments of the invention include rubber compositions, articles made from such rubber compositions, and methods for manufacturing them. Such embodiments include tire products.

[0055] The tire products according to the invention comprise a rubber composition based on a crosslinkable elastomer composition, which includes, for example, a highly unsaturated diene elastomer, reinforcing fillers, a vulcanizing agent, and an anti-ozone agent according to the invention. Detailed Implementation

[0056] The rubber composition according to the invention comprises an anti-ozone compound having formula (I).

[0057] (I)

[0058] in

[0059] X is selected from N or the CA group, where

[0060] At least one of X is N, but no more than two of X are N; and

[0061] in

[0062] A is H, CN, or an electron-donating group, and this electron-donating group is...

[0063] Directly bonded to the oxygen or nitrogen atom of the aromatic ring; or

[0064] It is aryl or C1-C 20 -alkyl, C1-C 20 -Alkenyl or C1-C 20 -alkoxy group;

[0065] and

[0066] R 1 R 1’ R 2 R 2’ Each of them independently chooses from the following groups: hydrogen, C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl, and wherein

[0067] R 1 or R 1’ One of them and R 2 or R 2' One of them can optionally form a double bond together;

[0068] and

[0069] R 3 R 3’ Selected independently from C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl.

[0070] The electron-donating group in the above definition can alternatively be aryl or alkyl. The term "aryl" describes any functional group or substituent derived from an aromatic ring, such as phenyl, naphthyl, thiophene, indole, etc.

[0071] C1-C 20 -alkyl, C1-C 20 -Alkenyl or C1-C 20 -Alkoxy groups can be straight-chain, branched, or cyclic, and typically contain 1 to 20 carbon atoms, meaning that any integer number of carbon atoms, from 1 to 20, falls within the definition of alkyl, alkenyl, or alkoxy. Alkyl groups can alternatively be represented by the formula CnH. 2n+1 (where n is 1 to 20) is described as above. In various embodiments, alkyl groups may be described as methyl, ethyl, propyl, butyl, tert-butyl, pentyl, hexyl, octyl, nonyl, or any isomer thereof.

[0072] For substituent R 1 R 1’ R 2R 2’ R 3 and R 3’ The defined aryl or C1-C 20 -alkyl and C1-C 20 -Alkenyl groups also apply.

[0073] In one embodiment of the invention, the R in the anti-ozone agent hydroquinoline derivative of formula (I) 1 and R 1' Each of the components is preferably selected independently from hydrogen or C1-C8-alkyl.

[0074] In one embodiment of the invention, the R in the anti-ozone agent hydroquinoline derivative of formula (I) 1 and R 1' Each is preferably selected independently from hydrogen or methyl.

[0075] In one embodiment of the present invention, R 1 or R 1' More preferably, it is methyl. In one embodiment of the invention, R 1 or R 1' One of them is more preferably methyl and the other is hydrogen.

[0076] In one embodiment of the invention, the R in the anti-ozone agent hydroquinoline derivative of formula (I) 2 and R 2' Each of the components is preferably selected independently from hydrogen or C1-C8-alkyl.

[0077] In one embodiment of the invention, the R in the anti-ozone agent hydroquinoline derivative of formula (I) 2 and R 2' Each is preferably selected independently from hydrogen or methyl.

[0078] In one embodiment of the present invention, R 1 or R 1' Hydrogen is a better choice than hydrogen.

[0079] In one embodiment of the present invention, R 2 Hydrogen is more preferably preferred.

[0080] In one embodiment of the invention, the R in the anti-ozone agent hydroquinoline derivative of formula (I) 3 and R 3’ Both are preferably selected independently of each other from C1-C8-alkyl groups.

[0081] In one embodiment of the present invention, R 3 and R 3' More preferably, both are independently selected from C1-C4-alkyl groups.

[0082] In one embodiment of the present invention, R 3 and R 3' The preferred choice between the two is methyl.

[0083] In another embodiment of the invention, the positions of the two nitrogen atoms in the aromatic portion of the anti-ozone compound are represented by the following two structures having formula (II.1a) or formula (II.1b):

[0084] (II.1a) or (II.1b).

[0085] The substituents are as defined above.

[0086] In one embodiment of the invention, the anti-ozone agent quinoline derivative preferably has formula (II.1a) or formula (II.1b), wherein

[0087] R 1 Indicates hydrogen or methyl;

[0088] R 2 Indicates hydrogen or methyl; and

[0089] R 3 and R 3’ Both are independently selected from C1-C8-alkyl, preferably methyl.

[0090] In one embodiment of the invention, the anti-ozone agent hydroquinoline derivative has formula (II.1a) or formula (II.1b), wherein R 1 Preferably, it represents methyl.

[0091] In one embodiment of the invention, the anti-ozone agent hydroquinoline derivative has formula (II.1a) or formula (II.1b), wherein R 2 Preferably, it represents hydrogen.

[0092] In one embodiment of the invention, the anti-ozone agent hydroquinoline derivative has formula (II.1a) or formula (II.1b), wherein R 3 and R 3' Both are preferably selected independently from C1-C4-alkyl groups.

[0093] In one embodiment of the invention, the anti-ozone agent hydroquinoline derivative has formula (II.1a) or formula (II.1b), wherein R 3 and R 3' The preferred form for both is methyl.

[0094] In another embodiment of the invention, the positions of the two nitrogen atoms in the aromatic portion of the anti-ozone compound are represented by the following two structures having formula (II.2a) or formula (II.2b):

[0095] (II.2a) or (II.2b).

[0096] The substituents are as defined above.

[0097] In one embodiment of the invention, the anti-ozone agent quinoline derivative preferably has formula (II.2a) or formula (II.2b), wherein

[0098] R 1 R 1’ Both are independently selected from hydrogen or C1-C8-alkyl.

[0099] Preferably, wherein

[0100] R 1 R 1’ Both are independently selected from hydrogen or C1-C4- groups.

[0101] Most preferably, one of R 1 or R 1' One is hydrogen and the other is methyl;

[0102] In one embodiment of the invention, the anti-ozone agent quinoline derivative preferably has formula (II.2a) or formula (II.2b), wherein

[0103] R 2 R 2’ Both are independently selected from hydrogen or C1-C8-alkyl.

[0104] Preferably, wherein

[0105] R 2 R 2’ Both are independently selected from hydrogen or C1-C4- groups.

[0106] The most preferred option is where R 2 or R 2' Both are hydrogen.

[0107] In one embodiment of the invention, the anti-ozone agent quinoline derivative preferably has formula (II.2a) or formula (II.2b), wherein R 3 and R 3' Both are independently selected from C1-C8-alkyl groups.

[0108] Preferably, R 3R 3' Both are independently selected from C1-C4- groups.

[0109] In one embodiment of the invention, the anti-ozone agent hydroquinoline derivative has formula (II.2a) or formula (II.2b), wherein most preferably, R 3 or R 3' Both are methyl groups.

[0110] In one embodiment of the invention, the anti-ozone agent hydroquinoline derivative has formula (II.2a) or formula (II.2b), wherein

[0111] R 1 Preferably, R represents methyl and 1' It is hydrogen;

[0112] R 2 and R 2’ Both are hydrogen.

[0113] R 3 and R 3’ Both are methyl groups.

[0114] In various embodiments, the ozone-resistant quinoline derivative according to the present invention has, for example, the following specific structures (III.1a) or (III.1b):

[0115] (III.1a); or (III.1b)

[0116] Wherein the substituent A is defined as above, preferably as defined below.

[0117] In a preferred embodiment, the ozone-resistant quinoline derivative according to the present invention has the following specific structure (III.2a) or (III.2b):

[0118] (III.2a); or (III.2b)

[0119] Wherein the substituent A is defined as above, preferably as defined below.

[0120] In another embodiment, the ozone-resistant hydroquinoline derivative according to the invention has, for example, the following specific structures (IV.1a) or (IV.1b):

[0121] (IV.1a); or (IV.1b)

[0122] The substituent X is as defined above.

[0123] In one embodiment, one of X is nitrogen and one of X is CH.

[0124] In another embodiment, both of X are nitrogen.

[0125] In a preferred embodiment, the ozone-resistant quinoline derivative according to the present invention has the following specific structure (IV.2a) or (IV.2b):

[0126] (IV.2a); or (IV.2b)

[0127] The substituent X is as defined above.

[0128] In one embodiment, one of X is nitrogen and one of X is CH.

[0129] In another embodiment, both of X are nitrogen.

[0130] Another example of an anti-ozone agent, a quinoline derivative, has the following structure:

[0131] (Va) (VI.a)

[0132] (VII.a) (VIII.a)

[0133] (IX.a) (Xa)

[0134] Another preferred embodiment of the anti-ozone agent hydroquinoline derivative has the following structure:

[0135] (Vb) (VI.b)

[0136] (VII.b) (VIII.b)

[0137] (IX.b) (Xb)

[0138] The electron-donating group represented by A has an atom directly bonded to the aromatic ring of the antioxidant with at least one lone pair of electrons; or A may alternatively be an aryl or alkyl group. The electron-donating group may alternatively be described as “EDG”, as understood in the art. In various embodiments, the electron-donating group has an atom, such as a nitrogen atom, a phosphorus atom, an oxygen atom, or a sulfur atom, which has at least one lone pair of electrons. For example, oxygen and sulfur typically each have two lone pairs of electrons, while nitrogen and phosphorus typically each have only one lone pair of electrons. The term “lone pair” describes a pair of valence electrons that are not shared with other atoms and / or are not used for chemical bonding. These electrons may also be described as non-bonded electron pairs. Preferred structures according to the invention will be represented by the formulas Va, VI.a, VII.a, VIII.a, IX.a, and Xa outlined above, and formulas Vb, VI.b, VII.b, VIII.b, IX.b, and Xb.

[0139] In various non-limiting embodiments, analogues to each of the above structures are explicitly contemplated, wherein one, two, or three of the methyl groups are each independently of each other as described above. 1 R 1’ R 2 R 2’ R 3 and R 3’ .

[0140] In other embodiments, the electron-donating group is selected from -NR. 4 2. -NH2, -OH, -OR 4 -NHCOR 4 or -OCOR 4 , where each R 4 They are C1-C8-alkyl groups, each independent of the others.

[0141] In another embodiment, the electron-donating group is -NH2.

[0142] In another embodiment, the electron-donating group is -OH.

[0143] In another embodiment, the electron-donating group is most preferably methoxy or ethoxy.

[0144] For example, the electron-donating group could be -NR 4 2, where each R 4 Independently, it is an alkyl group having 1 to 8 carbon atoms, as described above.

[0145] In one embodiment, each R 4 They are independently selected from C1-C4-alkyl groups.

[0146] In another embodiment, the electron-donating group is -OR4 , where R 4 It is an alkyl group having 1 to 8 carbon atoms, as described above.

[0147] In one embodiment, R 4 Preferably, it is a C1-C4-alkyl group.

[0148] In another embodiment, the electron-donating group is -NHCOR 4 , where R 4 It is an alkyl group having 1 to 8 carbon atoms, as described above.

[0149] In one embodiment, R 4 Preferably, it is a C1-C4-alkyl group.

[0150] In another embodiment, the electron-donating group is -OCOR 4 , where R 4 It is an alkyl group having 1 to 8 carbon atoms, as described above.

[0151] In one embodiment, R 4 Preferably, it is a C1-C4-alkyl group.

[0152] The electron-donating strength of the alkoxy or amine group mainly comes from the lone pairs of electrons on the O and N atoms, respectively, making R 4 Each of the groups may be a hydrogen or a saturated or unsaturated branched or straight-chain hydrocarbon moiety and / or may include one or more alicyclic groups and / or one or more aromatic hydrocarbons, or combinations thereof, without diminishing the electron-donating properties of the alkoxy or amine groups.

[0153] In such embodiments, the term "alicyclic" describes a saturated or unsaturated carbocyclic moiety comprising a monocyclic or bicyclic ring. Alicyclic groups typically comprise 3- to 7-membered saturated carbocyclic moieties. Examples of alicyclic moieties include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc., including their partially unsaturated derivatives such as cyclohexenyl, cyclopentenyl, etc.

[0154] Alternatively, the term "hydrocarbon group" may describe, for example, a hydrocarbon comprising 1 to 20 carbon atoms as described above, and includes saturated or unsaturated branched or straight-chain hydrocarbon moieties, which include aliphatic moieties and / or one or more alicyclic groups and / or one or more aromatic hydrocarbons or combinations thereof.

[0155] The electron-donating group can alternatively be a thiol, sulfide, thioether, or thioester (e.g., where the sulfur atom of the group is adjacent to the electron-donating group).

[0156] Alternatively, the electron-donating group can be phosphine.

[0157] Non-limiting examples of structures corresponding to various embodiments of the present invention are set forth in WO 2017 / 040961, such as the structures of formulas (XI) to (L) disclosed therein, which are incorporated herein by reference in their entirety. The structures of formulas (XI) to (L) in WO 2017 / 040961 are embodiments of the present invention, wherein R 1 or R 1’ One of them and R 2 or R 2' One of them does not form a double bond with the other, but each of them is independently selected from the following groups: hydrogen, C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl.

[0158] The object of the present invention is achieved by using partially hydrogenated quinoline derivatives as defined above, which are particularly suitable as anti-aging agents and / or anti-ozone agents in vehicle tires.

[0159] They can also be used to produce other industrial rubber products, such as rubber belts, (conveyor) belts, hoses, cables, automotive mounting parts, bushings, air springs, bellows, profiles, seals, diaphragms, tactile sensors for medical applications or robots, and, for example, shoe soles or their parts.

[0160] In the case of vehicle tires or other industrial rubber products, quinoline derivative compounds having formula (I) are particularly used in rubber compositions.

[0161] Therefore, as already mentioned, another subject of the present invention is a rubber composition.

[0162] The rubber composition according to the invention contains a quinoline derivative compound according to formula (I). The rubber composition according to the invention can, in principle, be any rubber composition, wherein the novel use of the quinoline derivative compound according to formula (I) achieves improved properties, particularly extended lifespan, through aging protection and / or ozone protection.

[0163] The rubber composition according to the present invention contains at least one type of rubber.

[0164] The rubber composition according to the invention preferably contains 0.1 to 10 phr (parts per 100), particularly preferably 0.2 to 5 phr, and very particularly preferably 0.3 to 3 phr of a compound according to formula I).

[0165] The term phr (parts per hundred parts by weight of rubber) used in this specification is a specification of the amount commonly used in the rubber industry for rubber compositions (like rubber compound formulations). In this document, the dosage of a single substance by weight is 100 parts by weight of the total mass of all high molecular weight rubber elastomers (Mw greater than 20,000 g / mol) present in the reference mixture.

[0166] The following describes additional components of the rubber composition according to the invention.

[0167] Rubber elastomers suitable for use with specific embodiments of the invention include highly unsaturated diene elastomers. According to an advantageous embodiment of the invention, the rubber composition according to the invention contains at least one diene rubber.

[0168] In another embodiment, the rubber composition contains diene rubber or a mixture of two or more different diene rubbers.

[0169] Diene rubber is a type of rubber produced by the polymerization or copolymerization of dienes and / or cyclic olefins, and therefore has C=C double bonds in the main chain or side groups.

[0170] Butadiene rubber is preferably selected from the group consisting of: natural polyisoprene (NR), synthetic polyisoprene (IR), epoxidized polyisoprene (ENR), (poly)butadiene rubber (BR), butadiene-isoprene rubber, styrene-butadiene rubber (SBR), solution-polymerized styrene-butadiene rubber (SSBR), emulsion-polymerized styrene-butadiene rubber (ESBR), styrene-isoprene rubber, isobutylene-isoprene rubber (IIR), butadiene copolymers, isoprene copolymers and mixtures of these elastomers, liquid rubber having a molecular weight Mw greater than 20,000 g / mol, polynorbornene-isoprene-isobutylene copolymer, acrylate rubber, fluororubber, silicone rubber, polysulfide rubber, epichlorohydrin rubber, styrene-isoprene-butadiene terpolymer, and hydrogenated styrene-butadiene rubber.

[0171] In this invention, alternatively, nitrile rubber, hydrogenated acrylonitrile butadiene rubber, chloroprene rubber, butyl rubber, halogenated butyl rubber and / or ethylene-propylene-diene rubber (EPDM) may be used in the production of industrial rubber products such as belts and hoses and / or shoe soles.

[0172] All natural and / or synthetic polyisoprene in all embodiments can be cis-1,4-polyisoprene and 3,4-polyisoprene, or their copolymers.

[0173] Polyisoprene includes synthetic cis-1,4 polyisoprene, characterized in that it may have greater than 90 mol.% or alternatively greater than 98 mol.% of cis-1,4 bonds.

[0174] Natural rubber (NR) is a cis-1,4-polyisoprene in which the cis-1,4- component is greater than 99% by weight. Additionally, mixtures of one or more natural polyisoprene with one or more synthetic polyisoprene are also conceivable.

[0175] Within the scope of this invention, the term "natural rubber" should be understood as naturally occurring rubber that can be obtained from rubber trees and "non-rubber tree" sources. Non-rubber tree sources are, for example, silver sap shrubs and soldering teeth (e.g., like TKS (rubbergrass; Russian dandelion)).

[0176] If butadiene rubber (= BR, polybutadiene) is included in the rubber composition according to the invention, it can be of all types known to those skilled in the art. These particularly include so-called high-cis and low-cis types, wherein polybutadiene having a cis content greater than or equal to 90% by wt.% is considered high-cis type, and polybutadiene having a cis content less than 90% by wt.% is considered low-cis type. Low-cis polybutadiene is, for example, Li-BR (lithium-catalyzed butadiene rubber) having a cis content of 20 to 50 wt.%. In the case of high-cis BR, particularly good properties and low hysteresis of the rubber composition are achieved.

[0177] The polybutadiene, or the polybutadiene used, can be modified by end-group modification and / or functionalization along the polymer chain. This modification can be those having hydroxyl and / or ethoxy and / or epoxy and / or siloxane groups and / or amino and / or aminosiloxane and / or carboxyl and / or phthalocyanine groups and / or silane groups and / or sulfide groups. Other known modifications (also known as functionalization) are also possible. Such functionalizations can be composed of metal atoms.

[0178] In cases where the rubber composition contains at least one styrene-butadiene rubber (styrene-butadiene copolymer), it can be both solution-polymerized styrene-butadiene rubber (SSBR) and emulsion-polymerized styrene-butadiene rubber (ESBR), wherein a mixture of at least one SSBR and at least one ESBR may also be used. The terms "styrene-butadiene rubber" and "styrene-butadiene copolymer" are used synonymously in the context of this invention.

[0179] The styrene-butadiene copolymer used may be end-group modified and / or functionalized along the polymer chain, having the modifications and functionalizations mentioned above for polybutadiene.

[0180] In one embodiment, at least one diene rubber is 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 halogenated butyl rubber.

[0181] According to a specific embodiment of the present invention, 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).

[0182] According to a specific embodiment of the invention, the rubber composition contains at least one natural polyisoprene (NR), for example, in an amount of 5 to 55 phr, and according to a specific embodiment of the invention, in an amount of 5 to 25 phr, very specifically 5 to 20 phr. This rubber composition exhibits good processability and recovery stability, as well as optimized tear properties and optimal rolling resistance behavior.

[0183] According to a specific embodiment of the invention, the rubber composition contains at least one polybutadiene (BR, butadiene rubber), for example, in an amount of 10 to 80 phr, particularly 10 to 50 phr, and according to a specific embodiment of the invention, in an amount of 15 to 40 phr. In this way, particularly good friction and wear properties and optimal braking behavior are achieved in the rubber composition according to the invention.

[0184] According to specific embodiments of the invention, the rubber composition contains at least one solution-polymerized or emulsion-polymerized styrene-butadiene rubber (SSBR or ESBR), for example, in an amount of 10 to 80 phr, particularly 30 to 80 phr, and according to specific embodiments of the invention, in an amount of 50 to 70 phr. This results in particularly good rolling resistance characteristics of the rubber composition according to the invention. According to particularly advantageous embodiments of the invention, SSBR and ESBR are used in combination with at least one other rubber to achieve an optimal and balanced property distribution.

[0185] Also suitable for use in specific embodiments of the invention are rubber elastomers, which are copolymers and include, for example, butadiene-styrene copolymers (SBR), butadiene-isoprene copolymers (BIR), isoprene-styrene copolymers (SIR), and isoprene-butadiene-styrene copolymers (SBIR), and mixtures thereof.

[0186] The elastomer system can be a blend of various elastomers having a total of 100 phr.

[0187] In view of the above, the rubber composition according to the present invention can be a mixture of rubbers from different sources.

[0188] In a particular embodiment, the rubber composition according to the invention comprises a mixture of one or more natural rubbers and one or more synthetic rubbers.

[0189] However, the rubber composition according to the invention may also contain only one or more synthetic rubbers.

[0190] In addition, the rubber composition according to the present invention may also contain only one or more natural rubbers.

[0191] The rubber composition preferably contains at least one filler, for example, in an amount of 30 to 500 phr, particularly 50 to 400 phr, and optionally 80 to 300 phr.

[0192] The reinforcing fillers used in the rubber compositions according to the invention include carbon black and / or silica (and related silane chemistry components).

[0193] Carbon black is an organic filler, well-known in the field of rubber compounding.

[0194] The rubber composition according to the invention contains at least one carbon black in amounts of 30 to 300 phr, particularly 30 to 200 phr, and more particularly 40 to 100 phr. In these amounts, carbon black is included as the sole filler or as the primary filler. If carbon black is present only as an additional filler besides a primary filler such as, in particular, silica (see below), the rubber composition according to the invention contains at least one carbon black in amounts of 0.1 to 60 phr, particularly 3 to 40 phr, and especially 5 to 30 phr.

[0195] Suitable carbon black is any carbon black known in the art and suitable for a given purpose. For example, any carbon black with a BET surface area or CTAB specific surface area both less than 400 m² / g, or alternatively between 20 and 200 m² / g, may be suitable for a particular embodiment based on the desired properties of the cured rubber composition. CTAB specific surface area is the external surface area determined according to the November 1987 standard AFNOR-NFT-45007. Suitable carbon blacks of the HAF, ISAF, and SAF types are commonly used in tire treads, for example. Non-limiting examples of carbon black include, for example, N 115, N134, N234, N299, N326, N330, N339, N343, N347, N375, and the 600 series carbon blacks (including, but not limited to, N630, N650, and N660 carbon blacks).

[0196] Silica can also be used as a reinforcing filler. Silica can be any known reinforcing silica, for example, any precipitated or ignited silica with both a BET surface area and a CTAB specific surface area less than 450 m² / g, or alternatively between 20 and 400 m² / g, can be used in specific embodiments based on the desired properties of the cured rubber composition.

[0197] Specific embodiments of the rubber compositions disclosed herein may include silica having CTAB in the range of 80 to 200 m² / g, 100 to 190 m² / g, 120 to 190 m² / g, or 140 to 180 m² / g.

[0198] This type of silica yields rubber compositions for tire treads, for example, with particularly good physical properties. Furthermore, the advantages of blending processing can result from reduced blending time and consistent product characteristics, leading to increased productivity. Commercially available examples of this type of silica are Ultrasil® VN3 (trade name) from Evonik and Zeosil® 1165 MP from Solvay.

[0199] According to a specific embodiment of the invention, the rubber composition contains silica as a filler, for example, in an amount of 30 to 500 phr, particularly 50 to 400 phr, and more particularly 80 to 300 phr. In these amounts, silica is particularly used as the sole or primary filler (based on a total filler content greater than 50% by weight).

[0200] According to another embodiment of the invention, in addition to another primary filler (such as, in particular, carbon black), the rubber composition also contains at least one silicate as an additional filler. In these cases, it is used in amounts of 5 to 100 phr, particularly 5 to 80 phr, and more particularly 10 to 60 phr.

[0201] According to a specific embodiment of the invention, the rubber composition contains at least one carbon black of 5 to 60 phr, particularly preferably 5 to 40 phr, and at least one silica of 50 to 300 phr, preferably 80 to 200 phr.

[0202] When silica is added to a rubber composition, a proportional amount of silane coupling agent is also added to the rubber composition. Silane coupling agents are sulfur-containing organosilicon compounds that react with the silanol groups of silica during mixing and with the elastomer during vulcanization to provide improved properties of the cured rubber composition. A suitable coupling agent is one capable of establishing sufficient chemical and / or physical bonding between the inorganic filler and the diene elastomer; thus, it is at least bifunctional, meaning capable of physically and / or chemically bonding with the inorganic filler. For example, a bond can be established between the silicon atoms of the coupling agent and the surface hydroxyl (OH) groups of the inorganic filler (e.g., surface silanols in the case of silica), and then another bond can be established with the diene elastomer, for example, via sulfur atoms (physically and / or chemically). Therefore, the silane coupling agent reacts with the surface silanol groups or other polar groups of silica during the mixing of the rubber or rubber composition (in situ) or even before the filler is added to the rubber (in the sense of pretreatment (pre-modification)).

[0203] The silane coupling agent used according to the present invention can be of all known types, and one or more different silane coupling agents can be used in combination with each other. Therefore, the rubber composition can contain a mixture of different silanes.

[0204] Coupling agents known from the prior art are bifunctional organosilanes, which have at least one alkoxy, cycloalkoxy, or phenoxy group as a leaving group on the silicon atom, and as another functional group, have (if appropriate) a group that can chemically react with the double bond of the polymer after cleavage. The last mentioned group can be, for example, the following chemical groups: —SCN, —SH, —NH2, or —S. x — (where x = 2 to 8).

[0205] Therefore, for example, 3-mercaptopropyltriethoxysilane, 3-thiocyanate-propyltrimethoxysilane, or 3,3′-bis(triethoxysilylpropyl) polysulfides having 2 to 8 sulfur atoms (e.g., 3,3′-bis(triethoxysilylpropyl)tetrasulfide (TESPT), the corresponding disulfide (TESPD)) or other mixtures of sulfides having 1 to 8 sulfur atoms (where the content of the various sulfides varies) can be used as silane coupling agents. TESPT can also be used, for example, with industrial carbon black (e.g., X50S from Evonik). ® The mixture of ) is added. Suitable silanes are described in WO 2008 / 083241 A1, WO 2008 / 083242 A1, WO 2008 / 083243 A1 and WO 2008 / 083244 A1.

[0206] Terminally capped mercaptosilanes, such as those known from WO 99 / 09036, can also be used as silane coupling agents. Commercially available silanes are sold by Momentive under the name NXT™ silane, or by Evonik Industries under the name VP Si 363. ® Sale.

[0207] Other alternative reinforcing fillers include, for example, carbon nanotubes (CNTs) (including discrete CNTs), so-called hollow carbon fibers (HCFs), and modified CNTs containing one or more functional groups (such as hydroxyl, carboxyl, and carbonyl groups), zeolites, graphite, and graphene, as well as so-called “carbon-silica biphase”.

[0208] Conventional non-reinforcing fillers (such as clay, bentonite, talc, chalk, kaolin, aluminosilicate, starch, magnesium oxide, and titanium dioxide) may also be present. In the context of this invention, other non-reinforcing fillers include rubber gels and fibers (such as aramid fibers, glass fibers, carbon fibers, and cellulose fibers).

[0209] Plasticizers that may also be present include oils and resins (derived from petroleum or other natural renewable resources, such as sunflower seeds and citrus peels). Processed oils are typically extracted from petroleum and are classified as paraffinic oils, aromatic oils, or naphthenic processed oils, including MES oils and TDAE oils. Processed oils may also include, in particular, plant-based oils such as sunflower oil, rapeseed oil, and vegetable oils. Some of the rubber compositions disclosed herein may include an elastomer (such as styrene-butadiene rubber) that has been incremented with one or more of these processed oils, however, such oils in the rubber compositions of certain embodiments are limited to no more than 40 phr of the total elastomer content of the rubber composition.

[0210] The rubber composition according to the invention is preferably used in a vulcanized state, particularly in vehicle tires or other vulcanized industrial rubber products.

[0211] The terms “vulcanized” and “crosslinked” are used synonymously in the context of this invention.

[0212] The vulcanization of the rubber composition according to the invention is preferably carried out in the presence of sulfur and / or by means of a vulcanization accelerator, some of which can also act as a sulfur donor.

[0213] Accelerators may be selected from the group consisting of: thiazole accelerators and / or mercapto accelerators and / or sulfenamide accelerators and / or thiocarbamate accelerators and / or thiuram accelerators and / or thiophosphate accelerators and / or thiourea accelerators and / or xanthate accelerators and / or guanidine accelerators. Other known vulcanizing agents, such as peroxides and ionic crosslinking agents, may also be used. Vulcanizing agents as used herein are those materials that cause rubber crosslinking and can therefore be added only to the production mixture to prevent premature curing; such agents are, for example, elemental sulfur or sulfur feeders, and peroxides.

[0214] The vulcanization system used can be based, in particular, on sulfur and accelerators. Any compound capable of acting as an accelerator for the vulcanization of an elastomer in the presence of sulfur can be used, especially those selected from the group consisting of, for example, sulfenamide accelerators such as: benzothiazolyl-2-sulfophenylmorpholine (MBS), 2-mercaptobenzothiazolyl disulfide (abbreviated “MBTS”), N-cyclohexyl-2-benzothiazolyl sulfenamide (abbreviated “CBS”), N,N-dicyclohexyl-2-benzothiazolyl sulfenamide (abbreviated “DCBS”), N-tert-butyl-2-benzothiazolyl sulfenamide (abbreviated “TBBS”), N-tert-butyl-2-benzothiazolyl sulfenimide (abbreviated “TBSI”), and mixtures of these compounds.

[0215] A primary accelerator of the sulfenamide type can be used as an embodiment of the present invention.

[0216] The rubber composition may also contain vulcanization retarders, vulcanization systems based on, for example, sulfur or peroxides, vulcanization accelerators, vulcanization activators, etc.

[0217] If the rubber composition contains a sulfur-donating substance, it is preferably selected from the group containing, for example, thiurams disulfides, such as tetrabenzylthiuram disulfide (TBzTD) and / or tetramethylthiuram disulfide (TMTD) and / or tetraethylthiuram disulfide (TETA); and / or thiurams tetrasulfides, such as dipentamethylenethiuram tetrasulfide (DPTT); and / or dithiophosphates, such as Didis (bis-(diisopropyl)thiophosphoryl disulfide) and / or bis(O,O-2-ethylhexylthiophosphoryl) polysulfides (e.g., Rhenocure SDT 50). ® Rheinchemie GmbH and / or zinc dichloroacyl dithiophosphate (e.g., Rhenocure ZDT / S®, Rheinchemie GmbH) and / or dialkyl dithiophosphate; and / or 1,6-bis(N,N-dibenzylthiocarbamoyl dithio)hexane and / or diaryl polysulfides and / or dialkyl polysulfides.

[0218] Other network formation systems (such as those based on the trade name Vulkuren) ® Duralink ® Or Perkalink ® Those available network-forming systems (such as those described in WO 2010 / 049216 A2) can also be used in the rubber compositions according to the invention.

[0219] The vulcanization system may further include various known auxiliary accelerators or vulcanization activators, such as zinc oxide or zinc complexes (e.g., zinc ethylhexanoate), fatty acids (e.g., stearic acid), and guanidine derivatives (especially diphenylguanidine or "DPG"). Particularly preferred are the use of accelerators TBBS and / or CBS and / or diphenylguanidine (DPG).

[0220] The total amount of these additives is, for example, 3 to 150 phr, particularly 3 to 100 phr and very particularly 5 to 80 phr.

[0221] As an additional additive, zinc oxide (ZnO) can be present in the amounts described above. These can be all types of zinc oxide known to those skilled in the art, such as ZnO granules or powders. Conventionally used zinc oxide typically has a BET surface area of ​​less than 10 m² / g. However, it is also possible to use zinc oxide with a BET surface area of ​​10 to 100 m² / g, such as so-called "nano zinc oxide".

[0222] In addition to the above, the rubber composition according to the invention may contain conventional additives in conventional weight parts, which are preferably added during at least one basic mixing stage in its preparation.

[0223] These optional general-purpose additives include:

[0224] • Reagents used to bind fillers, especially carbon black or silica, such as S-(3-aminopropyl)thiosulfate and / or its metal salts bound to carbon black (silane coupling agents bound to silica have been described above).

[0225] •Ozone-protective wax;

[0226] • Resins, especially adhesive resins used for inner tire components;

[0227] • Plasticizing aids, such as 2,2′-dibenzoamide diphenyl disulfide (DBD);

[0228] • Processing aids, such as fatty acid esters and metal soaps, such as zinc soaps and / or calcium soaps;

[0229] According to particularly advantageous embodiments, the rubber compositions according to the invention do not contain any additional anti-aging agents from the group consisting of p-phenylenediamine, except for Formula I according to the invention.

[0230] In particular, according to one embodiment, the rubber composition according to the invention may contain 0 to 1 phr of additional aging inhibitors based on diamines selected from the group consisting of: N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-xylyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine (7PPD).

[0231] Even with very small amounts of the mentioned diamine and the compound according to formula (I) of the present invention, it is still possible to achieve a good protective effect. In this case, the compound according to formula (I) of the present invention replaces the mentioned diamine known in the prior art.

[0232] According to another embodiment of the invention, at least one additional diamine aging inhibitor may also be present among the diamine aging inhibitors, such that the compound according to the invention partially replaces the diamines known in the prior art, thereby allowing conventional results without loss.

[0233] According to another embodiment, in addition to the compounds of formula (I) according to the invention, dihydroquinoline-based aging inhibitors (such as TMQ) may be present in the rubber composition. The amount of dihydroquinoline (such as TMQ in particular) present is, for example, 0.1 to 3 phr, particularly 0.5 to 1.5 phr.

[0234] Another subject of the invention is a vehicle tire comprising a rubber composition according to the invention, the rubber composition containing at least one compound having formula (I) as defined above.

[0235] The vulcanized vehicle tire has at least one vulcanized rubber of at least one rubber composition according to the invention in at least one component. It is known to those skilled in the art that most substances (such as the contained rubber) exist in a chemically modified form after mixing or only after vulcanization.

[0236] In the context of this invention, vehicle tires should be understood as pneumatic vehicle tires and solid rubber tires, including tires for industrial and construction site vehicles, trucks, passenger cars, and two-wheeled tires.

[0237] The vehicle tire according to the invention preferably has the rubber composition according to the invention in at least one external component, wherein the external component is preferably a tread, sidewall and / or bead profile.

[0238] Therefore, the vehicle tire according to the invention may optionally include a rubber composition according to the invention in a suitable composition, the rubber composition containing one or more compounds having formula (I) and a variety of other components as described above.

[0239] The production method and uses of the present invention are described below:

[0240] The rubber composition exemplified by this invention can be produced in a suitable mixer in a manner known to those skilled in the art. Typically, mixing can occur in two consecutive preparation stages: a first stage of thermomechanical processing at a high temperature, followed by a second stage of mechanical processing at a lower temperature.

[0241] The first stage, sometimes referred to as the “non-productive” stage, typically involves thoroughly mixing the various components of the composition by kneading, but excludes some components of the vulcanization system (such as vulcanizing agents, accelerators, and retarders). This first stage is carried out in a suitable kneading device (such as a Banbury-type internal mixer) until the mixture reaches a maximum temperature, typically between 120°C and 190°C, under the action of machining and high shear applied to the mixture, indicating that the components are well dispersed.

[0242] Following the cooling of the mixture, a second stage of machining is performed at a lower temperature. Sometimes referred to as the “productive” stage, this finishing stage involves incorporating some components (including vulcanizing agents, accelerators, and retarders) from the vulcanization system not added in the “non-productive” stage into the rubber composition using suitable equipment (such as an open mill). This is carried out at an appropriate time (typically, for example, between 1 and 30 minutes or between 2 and 10 minutes) and at a sufficiently low temperature (i.e., below the vulcanization temperature of the mixture) to prevent premature vulcanization.

[0243] Therefore, the rubber compositions according to the invention can be formed into useful articles, including tire components. For example, tire treads can be formed as tread strips and then subsequently made into part of a tire, or they can be formed directly onto the tire carcass by, for example, extrusion and then cured in a mold. Other components (such as those located in the bead region or sidewall of the tire) can be formed and assembled into a green tire and then cured by the curing of the tire.

[0244] According to a preferred development of the invention, a variety of accelerators are added during the final mixing stage in the production of the sulfur-crosslinkable rubber composition.

[0245] The sulfur-crosslinkable rubber composition according to the invention is prepared by methods conventional in the rubber industry, wherein a base mixture having all components except for the vulcanization system (sulfur and substances affecting vulcanization) is initially produced in one or more mixing stages. The final mixture is produced by adding the vulcanization system in a final mixing stage. The final mixture used is further processed, for example, by extrusion or calendering, to form the appropriate form.

[0246] Further processing is then carried out via vulcanization, wherein sulfur crosslinking is based on a vulcanization system added in the context of this invention. The rubber composition described above according to the invention is particularly suitable for use in vehicle tires, especially pneumatic vehicle tires.

[0247] For use in vehicle tires, the mixture is preferably introduced as a final mixture, then vulcanized into the form of a tread, and applied during the production of the vehicle tire blank as is known.

[0248] The rubber composition according to the invention is produced as described above for use as a sidewall or other carcass compound in vehicle tires. The difference lies in the extrusion process or molding after calendering of the compound. The final form of one or more different carcass compounds of uncured rubber composition is then used to construct a green tire.

[0249] In this context, the rubber composition of the tire's internal components is referred to as the tire compound, which includes, in essence, the inner core (inner layer), core profile, belt layer, shoulder, belt layer profile, carcass, bead reinforcement, bead profile, bead profile, and cord. The uncured tire blank is then vulcanized.

[0250] For the use of the rubber compositions according to the invention in other rubber articles such as belts, particularly in conveyor belts, the extruded or unvulcanized mixture is in the corresponding form and often provided with a strength carrier (e.g., synthetic fibers or steel cords). In most cases, this results in a multilayer structure consisting of one and / or more layers of rubber composition, one and / or more layers of the same and / or different strength members, and one and / or more additional layers and / or another rubber composition.

[0251] Therefore, in view of the above, the present invention also relates to the use of compounds according to formula (I) as anti-aging agents and / or anti-ozone agents in vehicle tires and / or industrial rubber products (e.g., rubber products such as air springs, bellows, conveyor belts, hoses, rubber belts, profiles, seals, diaphragms, tactile sensors for medical or robotic applications, or shoe soles or parts thereof). Example

[0252] The invention is further illustrated by the following examples, which are considered illustrative only and do not define the invention in any way. The characterization of the innovative anti-ozone molecule disclosed in the examples and the properties of the rubber compositions are evaluated as follows.

[0253] S. Synthesis Example

[0254] Synthesize the ozone-resistant compound according to the invention as described in WO 2017 / 040961.

[0255] S.1. Synthesis of 6-methoxy-2,2,4-trimethyl-3,4-dihydro-1H-1,5-naphthidine (compound 1.A)

[0256] In a 1-liter, three-necked round-bottom flask equipped with a reflux condenser connected to a nitrogen source, a thermocouple, and a magnetic stir bar, 52.48 g of 5-amino-2-methoxypyridine was dissolved in 500 mL of acetone. 6.8 g of iodine was added to the resulting solution. The resulting mixture was stirred under a nitrogen atmosphere and heated under reflux, with the internally measured reaction temperature at 60°C. After heating for 14 hours, the resulting mixture was cooled to ambient temperature and concentrated under vacuum to give a dark, viscous, crude oil.

[0257] The crude reaction mixture was dissolved in dichloromethane and passed through a short silica gel column (eluted with dichloromethane) to give 69 g (80% yield) of 1,2-dihydro-6-methoxy-2,2,4-trimethyl-1,5-naphthidine as a yellow oil.

[0258] ¾ NMR (500 MHz, CDCh): δ 1.26 (s, 6H), 2.05 (s, 3H), 3.4 (s, 1H), 3.86(s, 3H), 5.49 (s, 1H), 6.4 (d, 1H), 6.7 (d, 1H).

[0259] The reaction is further illustrated below:

[0260] Formula (IA)

[0261] Synthesis of S.2 6-methoxy-1,2,3,4-tetrahydro-2,2,4-trimethyl-1,5-naphthidine (compound 1.B)

[0262] In a 600 mL pressure flask equipped with a magnetic stir bar, 10 g of 1,2-dihydro-6-methoxy-2,2,4-trimethyl-1,5-naphthidine was dissolved in 30 mL of ethanol. Using an additional 25 mL of ethanol, 0.75 g of 10% palladium on carbon was added to the resulting solution as a catalyst to ensure complete transfer of the catalyst into the flask. The resulting mixture was purged with nitrogen and reacted at a hydrogen pressure of 20 to 40 psi until no more hydrogen was absorbed. The reaction mixture was then purged with nitrogen and filtered to remove the catalyst.

[0263] The filtrate was concentrated under vacuum to give 9.93 g (98% yield) of 6-methoxy-1,2,3,4-tetrahydro-2,2,4-trimethyl-1,5-naphthidine as a light amber oil.

[0264] ¾ NMR (500 MHz, CDCh): δ 1.17 (s, 3H), 1.24 (s, 3H), 1.39 (d, 3H), 1.5(t, 1H), 1.84 (dd, 1H), 2.93 (m, 1H), 3.05 (s, 1H), 3.87 (s, 6.41 (d, 1H), 6.76 (d, 1H) MS: m / z = 207 (M). + .

[0265] The reaction is further illustrated below:

[0266] Formula (IB)

[0267] After formation, the ozone-resistant efficacy of the anti-ozone agent with formula (IB) obtained in synthetic example S.2 was tested in the following examples.

[0268] The results are shown below.

[0269] T. Test Instance

[0270] Several testing systems are available for evaluating the efficacy and effectiveness of anti-ozone agents.

[0271] For example, anti-ozone migration and anti-ozonation lifetime testing can be evaluated by grading surface ozone cracks on prepared rubber samples (partially containing and partially not containing anti-ozone) after exposure to an ozone environment (e.g., for a specified duration in an ozone chamber). The migration rate in this process depends on various factors, such as the molecular size of the anti-ozone, the solubility and affinity of the anti-ozone in the rubber compound matrix, and environmental conditions.

[0272] T.1. Testing the antioxidant activity in synthetic raw rubber by viscosity measurement (minimum Mooney viscosity ML measured before and after heat aging according to ISO 289-1:2014).

[0273] Mooney viscosity testing is the most popular test method for characterizing polymers and uncured rubber materials, and the Mooney viscosity value is one of the important indicators for evaluating the processing properties of rubber because it is closely related to plasticity. Lower Mooney viscosity indicates better flowability, low molecular weight, and good plasticity of the rubber compound, while higher viscosity values ​​indicate high molecular weight and poor plasticity. As defined by international standards, the sample material is preheated in a closed mold cavity for a defined time period, and then sheared at a constant rate by an embedded rotor. The Mooney viscosity is recorded, and data are calculated at predefined times and viscosity points. In elastomer and tire studies, the Mooney viscometer test method is used to measure torque. MI (initial torque) is the torque recorded at time zero at the start of the test. Because the compound is heated under shear, the viscosity decreases, and the torque decreases. The minimum registered torque value is called ML. In general, it is a measure of the stiffness and viscosity of uncured rubber compounds. ML is expressed as ML(1+4) at 100°C, which indicates the final torque at 100°C after 4 minutes of testing using a large rotor, where the preheating time is 1 minute.

[0274] Materials used:

[0275] ESBR rubber: SBR 1502 emulsion (cold-polymerized 23.5% styrene SBR polymer made with mixed acid emulsifiers and non-staining stabilizers) from Petrochina Jiling.

[0276] Compound 1.B: The ozone-resistant agent AOz (6-methoxy-1,2,3,4-tetrahydro-2,2,4-trimethyl-1,5-naphthidine) of the present invention

[0277] Irganox ® 5057: Comparison with antioxidant AOx-1 (the reaction product of N-phenylaniline and 2,4,4-trimethylpentene)

[0278] Irganox ® 1076: Comparison with antioxidant AOx-2 (octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate)

[0279] Irganox ® 1520: Comparison with antioxidant AOx-3 (4,6-bis(octylthiomethyl)-o-cresol)

[0280] 6PPD: Compared to the ozone-resistant agent AOz-1 (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine)

[0281] Sirantox EPPD: Comparison with anti-ozone agent mixture AOz-2 (a mixture of 6PPD and 7PPD (N-(1,4-dimethylpentyl)-N'-phenyl-p-phenylenediamine, commercially available from Sinochem)).

[0282] Sample preparation:

[0283] The appropriate rubber stabilizers, as outlined in Table 1, were added to the SBR 1502 emulsion and thoroughly mixed. After coagulation, the raw rubber was dried and kneaded on a two-roll mill to produce flat raw rubber sheets, which were then subjected to oven aging. The Mooney viscosity before and after aging was measured.

[0284] Test conditions:

[0285] 1. Oven aging conditions: 100°C, 72 hours

[0286] 2. Measurement conditions:

[0287] • Sample size: 50 mm in diameter × 6 mm in thickness

[0288] • Rotor dimensions: Diameter 38.1 mm; Thickness 5.54 mm

[0289] • Test temperature: 100°C

[0290] • Preheating time: 1 min

[0291] • Running time: 4 min

[0292] • Equipment: Gotech MV-3000VS

[0293] result

[0294] The individual test results are listed in the table below.

[0295] Table T.1.a: Minimum Mooney viscosity of ESBR before and after 72 hours of heat aging at 100°C, without rubber stabilization and with rubber stabilization using compound 1.B of the present invention.

[0296]

[0297] b) Blank instance;

[0298] i) Examples of the present invention;

[0299] Table T.1.b: Minimum Mooney viscosity of ESBR before and after 72 hours of heat aging at 100°C under various antioxidant stabilization conditions.

[0300]

[0301] c) Comparative examples;

[0302] Table T.1.c: Minimum Mooney viscosity of ESBR before and after 72 hours of heat aging at 100°C with alternative anti-ozone agents for rubber stabilization.

[0303]

[0304] c) Comparative examples;

[0305] The results of comparing Table T.1a with Tables T.1b and T.1.c show that, compared with rubber without additional rubber stabilizers (Example B.1a), compound 1.B of the present invention (Example I.1g) can effectively stabilize uncured rubber and prevent it from degrading upon heat exposure, as evidenced by a significant reduction in Mooney viscosity change before and after heat exposure, and is also superior to or at a similar level to conventional antioxidants in Table T.1b.

[0306] Preferably, during the heat aging test, the viscosity of the raw rubber is maintained at its original level, i.e., no increase or decrease in viscosity is observed. The stabilizer that produces the least change in Mooney viscosity, measured before and after heat exposure, is the most effective stabilizer, protecting the raw rubber from both degradation and premature crosslinking.

[0307] T.2. Antioxidant activity in synthetic raw rubber was tested by color measurement (yellowness index (YI) according to ISO 17223:2014 before and after heat aging).

[0308] Sample preparation:

[0309] Obtain flat raw rubber sheets containing the rubber stabilizers shown in Table T.2 by following the procedure outlined in Example 1 above.

[0310] Test conditions:

[0311] 1. Oven aging conditions: 100°C, 7 days

[0312] 2. Measurement conditions:

[0313] • Sample size: 6 cm × 5 cm × 0.2 cm

[0314] • Equipment: CI60 colorimeter

[0315] • Test light source: CIE standard light source D65

[0316] • Color system: L a b

[0317] result

[0318] The individual test results are listed in the table below.

[0319] Table T.2.a: Yellowness index of ESBR before and after 7 days of heat aging at 100°C without rubber stabilizer and with the ozone-resistant compound 1.B of the present invention.

[0320]

[0321] b) Blank instance;

[0322] i) Examples of the present invention;

[0323] Table T.2.b: Yellowness index of ESBR before and after 7 days of heat aging at 100°C with a contrasting anti-ozone agent.

[0324]

[0325] c) Comparative examples;

[0326] Table T.2.c: Yellowness index of ESBR before and after 7 days of heat aging at 100°C with a contrasting anti-ozone agent.

[0327]

[0328] c) Comparative examples;

[0329] The values ​​in Tables T.2.a to T.2.c represent the average YI of two samples for each formulation. The initial color of the samples stabilized with EPPD and 6PPD was very deep (Table T.2.c). Therefore, it was not feasible to assess their color change by the YI index. The results show that compound 1.B (Example I.2g) produces a rubber composition with a relatively low initial color compared to 6PPD and Sirantox EPPD (Examples C.2e and C.2f). Furthermore, compound 1.B (Example I.2g) is able to stabilize the rubber composition from discoloration upon heat exposure, resulting in a lower discoloration (ΔYI) than most other additives tested, and even compared to known antioxidants (Table T.2.b).

[0330] T.3 Test of ozone resistance in cured synthetic rubber (test of resistance to static ozone cracking according to ISO 1431-1:2012)

[0331] ISO 1431-1:2012 specifies a procedure for estimating the crack resistance of vulcanized or thermoplastic rubbers when exposed to air containing a certain concentration of ozone at a defined temperature under static (or dynamic) tensile strain, excluding the effects of direct light.

[0332] Visual observation and / or image analysis are used to evaluate crack formation and growth. Changes in physical or chemical properties caused by exposure can also be determined.

[0333] Sample preparation:

[0334] Test samples of cured ESBR were prepared according to the procedure specified in ASTM D 3186.

[0335] The formulation used to prepare the ESBR mixture is as follows:

[0336]

[0337] According to ISO 1431-1:2004, at an ozone concentration of (50 ± 5) × 10 -8 Static ozone cracking resistance was tested in an ozone chamber at (40 ± 2) °C, maximum relative humidity of 65%, and strain of 20%, with samples tested per part / volume. Samples were evaluated after a 72-hour testing period. Three samples were tested for each formulation.

[0338] result

[0339] The individual test results are listed in the table below.

[0340] Table T.3.a: Results of static ozone cracking tests for compounds without rubber stabilizers and containing the ozone-resistant compound 1.B of the present invention.

[0341]

[0342] b) Blank instance;

[0343] i) Examples of the present invention;

[0344] Table T.3.b: Results of static ozone cracking tests with comparative antioxidants

[0345]

[0346] c) Comparative examples;

[0347] Table T.3.c: Results of static ozone cracking tests with comparative antiozone agents

[0348]

[0349] c) Comparison Examples

[0350] Tables T.3.a to T.3.c show the results of ozone degradation protection when testing the anti-ozone activity of different compounds against cured SBR. (Compared to Irganox) ® 1520 and Irganox ® Compared to the combination of 5057 (Example C.3.a), the ozone protection effect was significantly improved by using compound 1.B of the present invention (Example I.3d). In previous tests T.1 and T.2, this combination showed excellent antioxidant performance, thus demonstrating that high antioxidant efficiency is not necessarily associated with valuable ozone protection performance. Therefore, the ozone protection effect obtained with compound 1.B is unexpected and could not have been anticipated.

Claims

1. A rubber composition comprising an antiozone compound having formula (I). (I) in X is selected from N or the CA group, where At least one of X is N, but no more than two of X are N; and in A is H, CN, or an electron-donating group, and this electron-donating group is... Directly bonded to the oxygen or nitrogen atom of the aromatic ring; or is aryl or C1-C 20 - alkyl, C1-C 20 - alkenyl or C1-C 20 - alkoxy; and R 1 R 1’ R 2 R 2’ Each of them independently chooses from the following groups: hydrogen, C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl, and wherein R 1 or R 1’ One of them and R 2 or R 2' One of them can optionally form a double bond together; and R 3 R 3’ Selected independently from C1-C 20 -alkyl, C1-C 20 -Alkenyl or aryl.

2. The rubber composition according to claim 1, wherein, The anti-ozone agent has either of the following two structures having formula (II.1a) or formula (II.1b): (II.1a) or (II.1b).

3. The rubber composition according to claim 2, wherein, In equation (II.1a) or (II.1b): R 1 It is hydrogen or methyl, preferably methyl; R 2 It is hydrogen or methyl, preferably hydrogen; and R 3 R 3’ Both are independently selected from C1-C8-alkyl, preferably C1-C4-alkyl, and most preferably both are methyl.

4. The rubber composition according to claim 1, wherein, The anti-ozone agent has either of the following two structures having formula (II.2a) or formula (II.2b): (II.2a) or (II.2b).

5. The rubber composition according to claim 4, wherein, In equation (II.2a) or (II.2b): R 1 R 1’ Both are independently selected from hydrogen or C1-C8-alkyl groups, preferably C1-C4- groups, and most preferably one is hydrogen and the other is methyl; R 2 R 2’ Both are independently selected from hydrogen or C1-C8-alkyl groups, preferably C1-C4- groups, and most preferably both are hydrogen; and R 3 R 3’ Both are independently selected from C1-C8-alkyl, preferably C1-C4-alkyl, and most preferably both are methyl.

6. The rubber composition according to any one of claims 1 to 5, wherein, In equations (II.1a), (II.1b), (II.2a), or (II.2b), one of X is nitrogen and the other is CA.

7. The rubber composition according to claim 6, wherein, In formulas (II.1a), (II.1b), (II.2a), or (II.2b), one of X is nitrogen and the other is CH.

8. The rubber composition according to any one of claims 1 to 6, wherein, These electron-donating groups A At least one oxygen or nitrogen atom is directly bonded to an aromatic ring.

9. The rubber composition according to claim 8, wherein, A is selected from -NH2, -NHR 4 -NR 4 2 or -NHCOR 4 ,in Each R 4 The components are independently selected from C1-C8-alkyl groups, preferably C1-C4-alkyl groups, and most preferably A is -NH2.

10. The rubber composition according to claim 8, wherein, A is selected from -OH, -OR 4 or -OCOR 4 ,in R 4 It is a C1-C8-alkyl, preferably a C1-C4-alkyl, and most preferably wherein A is a hydroxyl, methoxy, or ethoxy group.

11. The rubber composition according to any one of claims 1 to 5, wherein, In formulas (II.1a), (II.1b), (II.2a), or (II.2b), X represents nitrogen.

12. The rubber composition according to any one of the preceding claims, comprising diene rubber, reinforcing filler, plasticizer and / or vulcanization system.

13. The rubber composition according to any one of the preceding claims, comprising at least a highly unsaturated diene rubber selected from the group consisting of: natural rubber, isoprene rubber, styrene-butadiene, polybutadiene, natural polyisoprene (NR), synthetic polyisoprene (IR), butadiene rubber (BR), solution-polymerized styrene-butadiene rubber (SSBR), emulsion-polymerized styrene-butadiene rubber (ESBR), butyl rubber (IIR), and halogenated butyl rubber and any combination thereof.

14. The rubber composition according to any one of the preceding claims, comprising a reinforcing filler selected from the group consisting of carbon black, silica, graphene, graphite, and combinations thereof.

15. The rubber composition according to any one of the preceding claims, comprising a plasticizer selected from the group consisting of oils, resins, and combinations thereof.

16. The rubber composition according to any one of the preceding claims, comprising a vulcanization system including sulfur and an accelerator.

17. The rubber composition according to any one of the preceding claims, wherein, The amount of the anti-ozone agent is between 0.2 and 10 phr, preferably between 0.5 and 3 phr.

18. A vehicle tire comprising, in at least one component, a rubber composition according to any one of claims 1 to 17.

19. The vehicle tire according to claim 18, wherein, The rubber composition is contained in an external component, wherein the external component is preferably a tread, sidewall, and / or a diamond-shaped structure.

20. Use of the compound of formula (I) according to claim 1 as an anti-aging agent and / or anti-ozone agent in vehicle tires and / or industrial rubber products.

21. The use according to claim 20, wherein, The rubber products are air springs, bellows, conveyor belts, hoses, rubber belts, profiles, seals, diaphragms, tactile sensors for medical or robotic applications, or shoe soles or parts thereof.

22. The use according to claim 20 or 21, wherein the use is as an ozone desiccant.

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