Phenothiazine compound, its uses and production processes, rubber mixture, and vehicle tires
Patent Information
- Application Number
- BR112023005608
- Authority / Receiving Office
- BR · BR
- Patent Type
- Patents
- Current Assignee / Owner
- Publication Date
- 2026-08-11
Abstract
Description
"Phenothiazine compound, its uses and production processes, rubber blend, and vehicle tires" Description
[0001] The present invention relates to a compound, a rubber mixture containing the compound, a vehicle tire comprising the rubber mixture in at least one component, a process for producing the compound and the use of the compound as an aging stabilizer and / or antioxidant and / or antiozonant and / or colorant.
[0002] It is known that vehicle tires and technical rubber articles employ polymeric materials, especially rubbers.
[0003] In the case of prolonged storage and especially in the target application, which is often at high temperatures, natural rubber and synthetic polymers (such as IR, BR, SBR, ESBR, etc.), but also natural and synthetic oils, fats and lubricants, are subject to oxidation reactions that have an adverse effect on the original desired properties. Depending on the type of polymer, the polymer chains are shortened until liquefaction of the material or subsequent hardening of the material occurs.
[0004] Aging stabilizers therefore play a decisive role in the durability of vehicle tires and other technical rubber articles.
[0005] Known aging stabilizers are aromatic amines, for example 6-PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine), IPPD (N-isopropyl-N'-phenyl-p-phenylenediamine) or SPPD (N-(1-phenylethyl)-N'-phenyl-p-phenylenediamine).
[0006] These molecules can react with oxygen or ozone or form free radicals, such as alkyl and alkylperoxy radicals, and Petition 870250022277, dated 03 / 21 / 2025, page 5 / 80 2 / 31 thus eliminate them and, consequently, protect the rubbers etc. from further oxidation reactions.
[007] However, aromatic amines have the disadvantage of being suspected of being carcinogenic and therefore dangerous to health, particularly considering that aniline or its derivatives can be released.
[008] Furthermore, the solubility of aging stabilizers in the medium to be protected must be taken into consideration. Aging stabilizers, such as IPPD, have the disadvantage that, in some cases, they are poorly soluble in rubbers and thus migrate to the surface and form a film that is usually colored. This effect is known as "blooming"; the aging stabilizer blooms out of the respective rubber. In addition to the appearance, this also has the disadvantage that the bloomed aging stabilizer is removed by rain, for example, causing a film to be reformed by additional migrating molecules and, in this way, the concentration of the aging stabilizer in the medium to be protected to continuously decrease. This results in a weaker protective effect than in the case without blooming and loss of the aging stabilizer.
[009] Aging stabilizers that react specifically with ozone and eliminate its effects are also referred to as antiozonants.
[010] It is an object of the invention to provide a usable compound, in particular, as an aging stabilizer in vehicle tires or other technical rubber articles, in order to achieve an enhanced protective effect on these articles based on the state of the art. In particular, the blooming behavior should be improved and, at the same time, a compound should be provided that is Petition 870260044259, dated 11 / 05 / 2026, page 9 / 86 3 / 31 less hazardous to health compared to the state of the art (aromatic amines).
[011] The objective is achieved by the inventive compound according to claim 1, by the inventive rubber mixture containing the compound and also by the inventive vehicle tire comprising the inventive rubber mixture in at least one component. The objective is further achieved by the process for producing the compound and by the use of the compound with an aging stabilizer and / or antioxidant and / or antiozonant.
[012] The compound according to claim 1 can also be used as a dye.
[013] The compound according to claim 1 exhibits the Formula I):
[014] The compound of Formula I) is, consequently, 3-(1,3-dimethylbutylamino)phenothiazine.
[015] The compound with Formula I) is a phenothiazine derivative. Phenothiazines / their derivatives are, among other things, used as a medicine, for example, for the treatment of Parkinson's disease, see document US 20130315825 A1, and are less hazardous to health compared to aromatic amines such as 6PPD or IPPD.
[016] However, phenothiazine itself is not as readily soluble in polymers, such as vehicle tire rubbers or other technical rubber articles, thus resulting in the described fluorescence problem. The compound according to the invention thus has the advantage of possessing a better protective effect compared to phenothiazine. Petition 870260044259, dated 11 / 05 / 2026, page 10 / 86 4 / 31
[017] Simultaneously, the compound according to the invention of Formula I) exhibits an improved protective effect compared to known anti-aging stabilizers, such as 6PPD, in particular, which is believed to be attributable to a high reactivity towards free radicals, for example. However, the invention is not expected to be linked to a specific mechanism of action or a specific explanation.
[018] US document 3413291 discloses phenothiazine derivatives. However, the derivatives disclosed here are also not readily soluble in rubbers, for example, N-isopropyl-10H-phenothiazine-3-amine. The inventive compound of Formula I) thus exhibits better solubility in polymers, such as rubbers, and, as such, an improved protective effect, compared to known phenothiazine derivatives due to the 1,3-dimethylbutyl group.
[019] Document CN 108069874 also discloses aging stabilizers based on phenothiazine derivatives. However, the derivatives disclosed here are simultaneously Schiff bases with the R2C=NR' portion (R' is not H, hydrogen) as shown, for example, in Formula S1) due to the substituents. S1) .
[020] These substances are susceptible to hydrolysis and exhibit a smaller protective effect, presumably since there is no sp3 hybridized α-H atom (alpha-hydrogen atom) in the vicinity of the phenyl-N group, as shown in S2). Petition 870260044259, dated 11 / 05 / 2026, p. 11 / 86 5 / 31 H S2)
[021] Compared to such Schiff-based phenothiazine derivatives, such as the compound of Formula S1), the inventive compound of Formula I) therefore has the advantages of being more stable, not being susceptible to hydrolysis and allowing a better protective effect.
[022] Document CN 106590827 discloses a phenothiazine derivative of Formula S3): S3)
[023] However, the compound with Formula S3) has the disadvantage of the -S-CH2-NH portion which, for example, in rubber mixtures for vehicle tires, can form / release thiols due to susceptibility to hydrolysis, which can cause undesirable pre-crosslinking (vulcanization) of the rubber mixture.
[024] Document CN 105272892 discloses aging stabilizers as shown in Formula S4) where phenol derivatives are linked to phenothiazine units via a thioacetate and amide linker. These linker units are also not advantageous for use in rubber blends to be vulcanized, since thioacetates are capping mercaptans that... Petition 870260044259, dated 11 / 05 / 2026, p. 12 / 86 6 / 31 decompose during vulcanization and, for example, can bond with diene-containing rubber. Furthermore, the amide portion lacks αH atoms which – as described above in relation to Formula S1) – reduces the effect of aging stabilizers.
[025] Document CN 107935867 discloses aging stabilizers as shown in Formula S5) that exhibit a free amine group (-NH2). This increases in a rubber mixture, for example, for vehicle tires or other technical rubber articles, the risk of premature crosslinking, which is also referred to as vulcanization. S)
[026] The inventive compound of Formula I) is particularly suitable as an aging stabilizer and / or antiozonant in vehicle tires and / or technical rubber articles, such as, in particular, a pneumatic spring, bellows, conveyor belt, belt, transmission belt, hose, elastic, profile, a seal, a membrane, tactile sensors for medical applications or robotic applications, or a shoe sole or parts thereof and / or oils and / or lubricants.
[027] The inventive compound of Formula I) is particularly Petition 870260044259, dated 11 / 05 / 2026, page 13 / 86 7 / 31 suitable for producing a rubber article, in particular an air spring, a bellows, conveyor belt, belt, transmission belt, hose, elastic band, profile, a seal, a membrane, tactile sensors for medical or robotic applications, or a shoe sole or parts thereof.
[028] To use the compound according to Formula I) in the articles or substances mentioned, said compound is used in a composition and used incorporated in said composition.
[029] In vehicle tires or other technical rubber articles, this is, in particular, a rubber mixture.
[030] The invention further provides for the use of the compound according to the invention of Formula I) in oils and lubricants, such as, in particular, fuels or engine fluids. The compound according to the invention can, consequently, be employed in engines.
[031] The present invention also provides for the use of the inventive compound according to Formula I) as a colorant in fibers and / or polymers and / or paper and / or in paints and coatings.
[032] The present invention therefore also provides a rubber mixture as mentioned above.
[033] The rubber mixture according to the invention has the compound of Formula I). The rubber mixture according to the invention can, in principle, be any rubber mixture in which the new inventive compound of Formula I) achieves improved properties, in particular greater durability through aging stabilization and / or the antiozonant effect.
[034] The rubber mixture of the invention contains at least one rubber.
[035] It is preferable when the rubber mixture according to the invention has 0.1 to 10 phr, particularly preferably 0.1 to 5 phr, most particularly preferably 1 to 5 phr, of Petition 870260044259, dated 11 / 05 / 2026, page 14 / 86 8 / 31 composed of Formula I).
[036] The unit phr (parts per hundred parts of rubber by weight) used in this document is the conventional quantity indication for mixture formulations in the rubber industry. The dosage of parts by weight of the individual substances is based in this document on 100 parts by weight of the total mass of all high molecular weight (Pm greater than 20,000 g / mol) and therefore of the solid rubbers present in the mixture.
[037] In advantageous embodiments of the invention, the rubber mixture according to the invention has at least one diene rubber.
[038] The rubber mixture may, therefore, contain a diene rubber or a mixture of two or more different diene rubbers.
[039] Diene rubbers are rubbers that are formed by polymerization or copolymerization of dienes and / or cycloalkenes and, therefore, have C=C double bonds in the main chain or in the side groups.
[040] Diene rubber is preferably selected from the group consisting of 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, liquid rubbers having a molecular weight Pm greater than 20000 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, acrylonitrile rubber Petition 870260044259, dated 11 / 05 / 2026, page 15 / 86 9 / 31 hydrogenated butadiene and hydrogenated styrene-butadiene rubber.
[041] Nitrile rubber, hydrogenated acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, halobutyl rubber and / or ethylene-propylene-diene rubber, in particular, are used in the production of technical rubber articles, such as belts, transmission belts and hoses and / or shoe soles. Mixture compositions known to those skilled in the art for these rubbers, which are specific in terms of fillers, plasticizers, vulcanization systems and additives, are preferably employed.
[042] Natural and / or synthetic polyisoprene of all forms may be cis-1,4-polyisoprene or 3,4-polyisoprene. However, the use of cis-1,4-polyisoprenes having a cis-1,4 content > 90% by weight is preferred. Such polyisoprene is obtainable firstly by stereospecific polymerization in solution with Ziegler-Natta catalysts or by using finely divided lithium alkyls. Secondly, natural rubber (NR) is such cis-1,4-polyisoprene, for which the cis-1,4 content in natural rubber is greater than 99% by weight.
[043] A mixture of one or more natural polyisoprenes with one or more synthetic polyisoprenes is also conceivable.
[044] In the context of the present invention, the term natural rubber should be understood as naturally occurring rubber that can be obtained from Hevea rubber trees and from non-Hevea sources. Non-Hevea sources include, for example, Guayule shrubs and dandelions, such as, for example, TKS (Taraxacum koksaghyz; Russian dandelion).
[045] If the rubber mixture of the invention contains butadiene rubber (i.e., BR, polybutadiene), this may be any of the types known to those skilled in the art. These include the Petition 870260044259, dated 11 / 05 / 2026, p. 16 / 86 10 / 31 designated as high cis and low cis types, with polybutadiene having a cis content of less than 90% by weight being designated as high cis type and polybutadiene having a cis content of less than 90% by weight being designated as low cis type. An example of a low cis polybutadiene is Li-BR (lithium-catalyzed butadiene rubber) having a cis content of 20% to 50% by weight. In particular, good properties and low hysteresis of the rubber mixture are achieved with a high cis BR.
[046] The polybutadiene (or polybutadienes) employed may be terminally modified with modifications and functionalizations and / or functionalized along the polymer chains. The modification 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 groups and / or carboxyl groups and / or phthalocyanine groups and / or silane-sulfide groups. However, other modifications known to those skilled in the art, also known as functionalizations, are also suitable. Metal atoms may be a constituent of such functionalizations.
[047] In the case where at least one styrene-butadiene rubber (styrene-butadiene copolymer) is present in the rubber mixture, this may be a solution-polymerized styrene-butadiene rubber (SSBR) or an emulsion-polymerized styrene-butadiene rubber (ESBR), and 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 the present invention.
[048] The styrene-butadiene copolymer used may be modified by a terminal group and / or functionalized along the polymer chains with the modifications and functionalizations mentioned. Petition 870260044259, dated 11 / 05 / 2026, page 17 / 86 11 / 31 above for polybutadiene.
[049] 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.
[050] In a particularly preferred embodiment of the 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).
[051] In a particularly advantageous embodiment of the invention, the rubber mixture comprises at least one natural polyisoprene (NR), preferably in amounts of 5 to 55 phr and, in a particularly advantageous embodiment of the invention, 5 to 25 phr, most particularly preferably 5 to 20 phr. Such a rubber mixture exhibits good processability and reversion stability and optimized tear properties and ideal rolling resistance characteristics.
[052] In a particularly advantageous embodiment of the invention, the rubber mixture comprises at least one polybutadiene (BR, butadiene rubber), preferably in amounts of 10 to 80 phr, particularly preferably 10 to 50 phr, and in a particularly advantageous embodiment of the invention, 15 to 40 phr. This achieves particularly good tear and abrasion properties of the rubber mixture according to the invention and ideal braking characteristics.
[053] In a particularly advantageous embodiment of the invention, Petition 870260044259, dated 11 / 05 / 2026, page 18 / 86 12 / 31 The rubber mixture comprises at least one solution polymerized styrene-butadiene rubber (SSBR), preferably in amounts of 10 to 80 phr, particularly preferably 30 to 80 phr, and in a particularly advantageous embodiment of the invention, 50 to 70 phr. This achieves particularly good rolling resistance properties of the rubber mixture according to the invention. In particularly advantageous embodiments of the invention, SSBR is employed in combination with at least one additional rubber to achieve an ideal and balanced property profile.
[054] It is preferable that the rubber mixture contain at least one filler, preferably in quantities of 30 to 500 phr, particularly preferably 50 to 400 phr, in turn preferably 80 to 300 phr.
[055] In advantageous embodiments of the invention, the filler is a reinforcing filler that is preferably selected from the group consisting of carbon blacks and silicas.
[056] In particularly advantageous embodiments of the invention, the rubber mixture has at least one silica as a filler, preferably in amounts of 30 to 500 phr, particularly preferably 50 to 400 phr, in turn preferably 80 to 300 phr.
[057] In these amounts, the silica is especially present as a single or primary filler (more than 50% by weight based on the total amount of filler).
[058] In other advantageous embodiments of the invention, the rubber mixture has at least one silica as an additional filler, preferably in amounts of 5 to 100 phr, particularly preferably 5 to 80 phr, in turn preferably 10 to 60 phr.
[059] In these quantities, silica is especially present as an additional filler, in addition to another primary filler, such as, in particular, carbon black. Petition 870260044259, dated 11 / 05 / 2026, p. 19 / 86 13 / 31
[060] Silica can be any of the types of silica known to those skilled in the art that are suitable as a filler for tire rubber compounds. However, particular preference is given to the use of finely divided precipitated silica having a nitrogen surface area (BET surface area) (according to DIN ISO 9277 and DIN 66132) of 35 to 400 m² / g, preferably 35 to 350 m² / g, more preferably 85 to 320 m² / g, very preferably 120 to 235 m² / g, and a CTAB surface area (according to ASTM D 3765) of 30 to 400 m² / g, preferably 30 to 330 m² / g, more preferably 80 to 300 m² / g, very preferably 115 to 200 m² / g. Such silicas lead, for example, in rubber compounds for tire treads, to particularly good physical properties of the vulcanized materials.Advantages in mixing processes through a reduction in mixing time can also result here while retaining the same product properties, leading to improved productivity. The silicas used can, for example, be those of the Ultrasil® VN3 type (trade name) available from Evonik or highly dispersible silicas known as HD silicas (e.g., Zeosil® 1165 MP available from Solvay).
[061] Where at least two different silicas, differing, for example, in their BET surface area, are present in the rubber mixture of the invention, the quantity figures indicated refer to the total quantity of all silicas present.
[062] The terms silicic acid and silica are used synonymously in the context of the present invention.
[063] The rubber mixture may additionally contain additional fillers, such as, in particular, carbon blacks, in particular, industrial carbon blacks or pyrolysis carbon blacks, or reinforced or unreinforced fillers. Petition 870260044259, dated 11 / 05 / 2026, page 20 / 86 14 / 31
[064] Within the context of the present invention, additional (non-reinforced) fillers include aluminosilicates, kaolin, chalk, starch, magnesium oxide, titanium dioxide or rubber gels and also fibers (for example, aramid fibers, glass fibers, carbon fibers, cellulose fibers).
[065] Furthermore, optionally reinforced fillers are, for example, carbon nanotubes (CNTs), including distinct 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 is known as carbon-silica double-phase filler.
[066] In the context of the present invention, zinc oxide is not included among the fillers.
[067] In particularly advantageous embodiments of the invention, the rubber mixture according to the invention has 0.1 to 60 phr, preferably 3 to 40 phr, particularly preferably 5 to 30 phr, most particularly preferably 5 to 15 phr of at least one carbon black. In these quantities, the carbon black is present especially as an additional filler, in addition to a primary filler, such as, in particular, silica.
[068] In further advantageous embodiments of the invention, the rubber mixture according to the invention has 30 to 300 phr, preferably 30 to 200 phr, and particularly preferably 40 to 100 phr, of at least one carbon black. In these quantities, the carbon black is present as a single or primary filler and is therefore optionally present in combination with silica in the smaller quantities mentioned above.
[069] Suitable carbon blacks include any types of carbon blacks familiar to those skilled in the art.
[070] In one embodiment, carbon black exhibits a Petition 870260044259, dated 11 / 05 / 2026, p. 21 / 86 15 / 31 iodine number according to ASTM D 1510, also known as the iodine adsorption number, between 30 and 250 g / kg, preferably 30 to 180 g / kg, particularly preferably 40 to 180 g / kg and, very particularly preferably 80 to 150 g / kg, and a DBP number according to ASTM D 2414 of 30 to 200 mL / 100 g, preferably 70 to 200 mL / 100 g, particularly preferably 90 to 200 mL / 100 g.
[071] The DBP number according to ASTM D 2414 determines the specific absorption volume of a carbon black or light-colored filler by means of dibutyl phthalate.
[072] The use of such a type of carbon black in the rubber compound, in particular for vehicle tires, ensures the best possible compromise between abrasion resistance and heat buildup, which in turn influences the ecologically relevant rolling resistance. Preference is given here to only one type of carbon black being used in the respective rubber compound, but it is also possible to mix several types of carbon black in the rubber compound.
[073] In a particularly advantageous embodiment of the invention, the rubber mixture has 5 to 60 phr, particularly preferably 5 to 40 phr, of at least one carbon black and 50 to 300 phr, preferably 80 to 200 phr, of at least one silica.
[074] The rubber mixture may additionally contain commonly used additives in customary weight proportions, which are preferably added at least once during the primary mixing stage of the production of said mixture. These additives include a) aging stabilizers known in the art, for example diamines, such as N-Phenyl-N'-(1,3dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-p-phenylenediamine (DTPD), N-(1,4-dimethylpentyl)-N' Petition 870260044259, dated 11 / 05 / 2026, page 22 / 86 16 / 31 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, for example, zinc oxide and fatty acids (e.g., stearic acid) and / or other activators, such as zinc complexes, for example, zinc ethylhexanoate, c) activators and / or charge-binding agents, in particular carbon black or silica, for example, S-(3-aminopropyl)thiosulfuric acid and / or metal salts thereof (carbon black bonding) and silane coupling agents (silica bonding), d) antiozonant waxes, (e) resins, especially tackifying resins for internal tire components, f) chewing aids, for example 2,2'-dibenzamidodiphenyl disulfide (DBD), and (g) processing aids, such as, in particular, acid esters and metallic soaps, for example, zinc soaps and / or calcium soaps, h) plasticizers, such as, in particular, aromatic, naphthenic or paraffinic mineral oil plasticizers, for example, MES (moderate extraction solvate) or RAE (residual aromatic extract) or TDAE (treated distilled aromatic extract) or liquid rubber oils (RTL) or liquid biomass oils (BTL), preferably having a polycyclic aromatic content of less than 3% by weight, according to method IP 346 or triglycerides, for example rapeseed oil or factics or hydrocarbon resins or liquid polymers having an average molecular weight (determination by GPC = gel permeation chromatography, according to BS ISO 11344:2004) between 500 and 20000 g / mol. Petition 870260044259, dated 11 / 05 / 2026, page 23 / 86 17 / 31
[075] When using mineral oil, it is preferably selected from the group consisting of DAE (distilled aromatic extracts) and / or RAE (residual aromatic extracts) and / or TDAE (treated distilled aromatic extracts) and / or MES (solvent-moderated extracted) and / or naphthenic oils.
[076] In particularly advantageous embodiments, the rubber mixture according to the invention does not contain other aging stabilizers from the p-phenylenediamine group, see list above a), in addition to the inventive compounds of Formula I). In a particularly preferred embodiment, the rubber mixture according to the invention especially contains 0 to 0.1 phr, in particular 0 phr, of other diamine-based aging stabilizers selected from the containing group, particularly preferably consisting of N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), 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).
[077] Preferably very small quantities from 0 to 0.1 phr, particularly preferably 0 phr, of the aforementioned diamines and the compound of Formula I) present according to the invention make it possible to achieve an improved protective effect. The inventive compound of Formula I) replaces the aforementioned diamines known in the prior art.
[078] In other advantageous embodiments of the invention, at least one additional representative of the diamine aging stabilizers mentioned is present and, as such, the compound according to the invention only partially replaces the diamines known in the prior art. This also achieves the advantage according to the invention, only not in an optimized way.
[079] In advantageous configurations, stabilizers of Petition 870260044259, dated 11 / 05 / 2026, page 24 / 86 18 / 31 aging agents based on dihydroquinoline, such as TMQ, are present in the rubber mixture in addition to the inventive compound of Formula I). The amount of dihydroquinolines present, especially TMQ, is preferably 0.1 to 3, in particular 0.5 to 1.5 phr.
[080] In other advantageous embodiments, the rubber mixture according to the invention does not contain other aging stabilizers, i.e., 0 phr of other aging stabilizers besides the inventive compound of Formula I).
[081] Silane coupling agents may be any of the types known to those skilled in the art.
[082] Furthermore, one or more different silane coupling agents may be used in combination with each other. The rubber mixture may thus contain a mixture of different silanes.
[083] Silane coupling agents react with silica surface silanol groups or other polar groups during rubber mixing / rubber blending (in situ) or in the context of a pretreatment (pre-modification) even before the addition of filler to the rubber.
[084] The coupling agents known from the prior art are bifunctional organosilanes having at least one alkoxy, cycloalkoxy or phenoxy group as a leaving group on the silicon atom and having as another functionality a group that, possibly after cleavage, can enter into a chemical reaction with the double bonds of the polymer. The latter group may comprise, for example, the following chemical groups: -SCN, -SH, -NH2 or -Sx- (with x = 2 to 8). [0 85] The silane coupling agents that can be employed in this way include, for example, 3-mercaptopropyltriethoxysilane, 3Petition 870260044259, dated 11 / 05 / 2026, page 25 / 86 19 / 31 thiocyanatopropyltrimethoxysilane or 3,3'-bis(triethoxysilylpropyl) polysulfides containing 2 to 8 sulfur atoms, for example, 3,3'-bis(triethoxysilylpropyl) tetrasulfide (TESPT), the corresponding disulfide (TESPD), or mixtures of sulfides containing 1 to 8 sulfur atoms with varying sulfur contents. TESPT, for example, can also be added as a mixture with carbon black (trade name X50S® from Evonik).
[086] Blocked mercaptosilanes, as known, for example, from WO 99 / 09036, can also be used as a silane coupling agent. It is also possible to use silanes as described in WO 2008 / 083241 A1, WO 2008 / 083242 A1, WO 2008 / 083243 A1 and WO 2008 / 083244 A1. It is also possible to use, for example, silanes that are marketed under the name NXT in numerous variants by Momentive, USA, or those that are marketed under the name VP Si 363® by Evonik Industries.
[087] The total proportion of additional additives is preferably 3 to 150 phr, more preferably 3 to 100 phr and, most preferably, 5 to 80 phr.
[088] Zinc oxide (ZnO) may be included in the total proportion of additional additives in the quantities mentioned above.
[089] This can be any type of zinc oxide known to those skilled in the art, for example, ZnO granules or powders. Conventionally used zinc oxide generally has a BET surface area of less than 10 m2 / g. However, it is also possible to use a zinc oxide having a BET surface area of 10 to 100 m2 / g, for example, called nano zinc oxides.
[090] The rubber mixture according to the invention is preferably used in vulcanized form, in particular in tires. Petition 870260044259, dated 11 / 05 / 2026, page 26 / 86 20 / 31 of vehicles or other articles of vulcanized technical rubber.
[091] The vulcanization of the rubber mixture of the invention is preferably carried out in the presence of sulfur and / or sulfur donors with the aid of vulcanization accelerators, some vulcanization accelerators being able to act simultaneously as sulfur donors. The accelerator is 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 xanthogenate accelerators and / or guanidine accelerators.
[092] It is preferable to use a sulfenamide accelerator selected from the group consisting of N-cyclohexyl-2-benzothiazolsulfenamide (CBS) and / or N,N-dicyclohexylbenzothiazol-2-sulfenamide (DCBS) and / or benzothiazyl-2-sulfenomorpholide (MBS) and / or N-tert-butyl-2-benzothiazylsulfenamide (TBBS) or a guanidine accelerator such as diphenylguanidine (DPG).
[093] The sulfur donor substances used may be any sulfur donor substances known to those skilled in the art. If the rubber mixture contains a sulfur donor substance, the latter is preferably selected from the group comprising, for example, thiuram disulfides, for example, tetrabenzylthiuram disulfide (TBzTD) and / or tetramethylthiuram disulfide (TMTD) and / or tetraethylthiuram disulfide (TETD) and / or thiuram tetrasulfides, for example, dipentamethylenethiuran tetrasulfide (DPTT) and / or dithiophosphates, for example
[094] DipDis (bis(diisopropyl)thiophosphoryl disulfide) and / or bis(O,O-2-ethylhexylthiophosphoryl) polysulfide (e.g., Rhenocure SDT 50®, Rheinchemie GmbH) and / or zinc dichlorodithiophosphate (e.g., Rhenocure ZDT / S®, Rheinchemie GmbH) and / or Petition 870260044259, dated 11 / 05 / 2026, page 27 / 86 21 / 31 zinc alkyldithiophosphate and / or 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane and / or diaryl polysulfides and / or dialkyl polysulfides.
[095] Other network-forming systems, such as those that can be obtained, for example, under the trade names Vulkuren®, Duralink® or Perkalink®, or network-forming systems as described in WO 2010 / 049216 A2, can also be used in the rubber mixture. This system has a vulcanizing agent that crosslinks with a functionality greater than four and at least one vulcanization accelerator.
[096] It is particularly preferable to use TBBS and / or accelerators CBS and / or diphenylguanidine (DPG).
[097] Vulcanization retarders may also be present in the rubber mixture.
[098] The terms vulcanized and crosslinked are used synonymously in the context of the present invention.
[099] In a preferred embodiment of the invention, a plurality of accelerators is added in the final mixing step during the production of the sulfur-containing crosslinkable rubber mixture.
[0100] The crosslinkable rubber mixture with sulfur of the invention is produced by the usual process in the rubber industry, in which, in one or more mixing stages, a base mixture comprising all constituents except the vulcanization system (sulfur and substances that influence vulcanization) is first produced. The finished mixture is produced by adding the vulcanization system in a final mixing stage. The finished mixture is, for example, further processed and shaped into the appropriate form by means of an extrusion or calendering operation.
[0101] This is followed by further processing by vulcanization, in which sulfur crosslinking occurs due to the system Petition 870260044259, dated 11 / 05 / 2026, page 28 / 86 22 / 31 vulcanization added in the context of the present invention.
[0102] The rubber mixture described above in the invention is particularly suitable for use in vehicle tires, especially pneumatic vehicle tires.
[0103] For use in vehicle tires, the mixture, as a finished mixture before vulcanization, is preferably made into tread form and applied in the manner known during the production of the raw vehicle tire.
[0104] The production of the rubber mixture of the invention, for use as a sidewall or other body mixture in vehicle tires, is carried out as already described. The difference lies in the shaping after the extrusion / calendering operation of the mixture. The shapes thus obtained from the unvulcanized rubber mixture for one or more different body mixtures then serve for the construction of a blank tire.
[0105] Body mixture refers here to the rubber mixtures for the internal components of a tire, such as essentially the windshield wiper, inner liner (inner layer), core profile, belt, shoulder, belt profile, carcass, bead reinforcement, bead profile, flange profile and tread. The raw tire, not yet vulcanized, is subsequently vulcanized.
[0106] For use of the rubber mixture of the invention in transmission belts and other belts, especially in conveyor belts, the extruded unvulcanized mixture is placed in the appropriate form and often supplied at the same time or subsequently with strength members, for example, synthetic fibers or steel cables. This generally produces a multi-layered construction consisting of one and / or more layers of rubber mixture, one and / or more layers of identical and / or different strength members, and one and / or more additional layers of Petition 870260044259, dated 11 / 05 / 2026, page 29 / 86 23 / 31 same and / or another rubber mixture
[0107] The present invention further provides a vehicle tire comprising the rubber mixture according to the invention containing the compound according to the invention in at least one component.
[0108] The vulcanized vehicle tire comprises at least one component, a vulcanized rubber compound according to the invention. One skilled in the art is aware that most substances, for example, the rubbers present, are present in a chemically altered form immediately after mixing or only after vulcanization.
[0109] Within the context of the present invention, vehicle tires should be understood as pneumatic vehicle tires and solid rubber tires, including tires for industrial and construction vehicles, truck tires, car tires and two-wheeled vehicle tires.
[0110] The vehicle tire according to the invention preferably comprises the rubber mixture according to the invention in at least one external component, wherein the external component is preferably a tread, a sidewall and / or a flange profile.
[0111] The vehicle tire according to the invention may thus also comprise the rubber mixture according to the invention containing the inventive compound of Formula I) in two or more components of optionally adapted composition.
[0112] The present invention further provides a process for producing the compound of Formula I), wherein the process comprises at least the following process steps: a) provide the substance of Formula A) Petition 870260044259, dated 11 / 05 / 2026, page 30 / 86 24 / 31 THE) b) to provide methyl isobutyl ketone (MIBK) and hydrogen (H2); c) react the substance according to step a) with the substances according to step b), preferably in the presence of a hydrogenation catalyst, to generate the substance of Formula I)
[0113] The present invention also provides an additional process for producing the compound of Formula I), wherein the process comprises at least the following process steps: a1) providing the substance of Formula A) THE) b1) provide a reducing agent, in particular tin(II) chloride dihydrate; c1) react the substance according to step a1) with the substance from step b1) to generate the substance of Formula C1) C1) d1) provide methyl isobutyl ketone (MIBK) and hydrogen (H2); Petition 870260044259, dated 11 / 05 / 2026, p. 31 / 86 25 / 31 e1) react the substance of Formula C1) with the substances according to step d1), preferably in the presence of a hydrogenation catalyst, to generate the substance of Formula I)
[0114] The substance methyl isobutyl ketone (MIBK) is commercially available.
[0115] The reducing agent may be any reducing agent known to one skilled in the art and suitable for reducing the nitro group (NO2) to an amino group (-NH2). Tin(II) chloride dihydrate is especially suitable. This is commercially available.
[0116] The process of steps a) ac) is preferable to the process of steps a1) to e1), since fewer process steps are required.
[0117] It is preferable when the process steps in which a reaction with hydrogen is carried out employ a suitable catalyst, referred to in the context of the present invention as a hydrogenation catalyst.
[0118] The hydrogenation catalyst for the processes (step c) / e1)) is preferably a noble metal catalyst, such as, in particular, palladium (Pd) or platinum (Pt). The noble metal is preferably employed in carbon (C), such as palladium in carbon (Pd / C) or platinum in carbon (Pt / C).
[0119] It is also possible to use other known catalysts, such as Raney nickel or copper chromite.
[0120] It is preferable when Pt / C is used in step c).
[0121] It is preferable when Pd / C is used in step e1). Petition 870260044259, dated 11 / 05 / 2026, page 32 / 86 26 / 31
[0122] The hydrogen pressure in the respective process steps where hydrogen is used is preferably from 1 to 50 bar, particularly preferably from 10 to 45 bar. According to an advantageous embodiment of the invention, a pressure of 20 to 40 bar is preferred.
[0123] The hydrogenation reaction in step c) / e1) is preferably carried out in an autoclave, in particular a stainless steel autoclave.
[0124] The temperature in process steps c) and e1) is preferably from ambient temperature (RT, in particular 20 °C) to 150 °C, preferably 130 °C.
[0125] The present invention also provides an additional process for producing the compound of Formula I), wherein the process comprises at least the following process steps: a2) providing the substance of Formula A2): A2) b2) provide elemental sulfur and o-dichlorobenzene (orthodichlorobenzene); c2) react the substance from step a2) with the substances from step b2) to generate the substance of Formula I)
[0126] The invention will be further elucidated below with Petition 870260044259, dated 11 / 05 / 2026, p. 33 / 86 27 / 31 reference to work examples.
[0127] The Formula I component was produced as follows: X1): Synthesis of the inventive compound of Formula I) (3-(1,3-dimethylbutylamino)phenothiazine) according to process steps a) ac):
[0128] 0.50 g (2.05 mmol, 1 eq.) of 3-nitrophenothiazine, 0.18 g of platinum on carbon (5%) (0.4 g in 4.67 mmol of substrate) and 20.0 mL of methyl isobutyl ketone were weighed into a stainless steel autoclave fitted with a Teflon inner lining. The autoclave was then pressurized to 40 bar with hydrogen and stirred at 120 °C for 10 hours. After the reaction was complete, the excess hydrogen was blown off and the suspension filtered through diatomaceous earth (Celite®) and washed with ethanol. The filtrate was concentrated to dryness and dried under vacuum. Grayish to violet solid; yield 0.57 g (93% of theory).
[0129] 1H-NMR (500 MHz, DMSO-d6) δ = 8.09 (s, 1H), 6.94 (td, J = 7.6, 1.5 Hz, 1H), 6.88 (dd, J = 7.6, 1.4 Hz, 1H), 6.69 - 6.63 (m, 2H), 6.51 (d, J = 8.4 Hz, 1H), 6.27 (dd, J = 8.5, 2.5 Hz, 1H), 6.21 (d, J = 2.5 Hz, 1H), 4.82 (d, J = 8.9 Hz, 1H), 3.30 (dt, J = 8.6, 6.5 Hz, 1H), 1.70 (dp, J = 13.5, 6.7 Hz, 1H), 1.38 (dt, J = 13.9, 7.1 Hz, 1H), 1.16 (dt, J = 13.5 Hz, 1H), 1.02 (dt, J = 8.6, 6.5 Hz, 1H), 1.17 (dp, J = 6.7 Hz, 1H).
[0130] 13C-NMR (126 MHz, DMSO-d6) δ = 144.5, 143.9, 131.8, 127.7, 126.6, 121.0, 117.6, 116.5, 115.8, 114.4, 112.1, 110.7, 46.5, 46.4, 25.0, 23.2, 23.0, 21.2. ESI-MS (electrospray ionization mass spectrometry) [M+H]+= 299. Petition 870260044259, dated 11 / 05 / 2026, p. 34 / 86 28 / 31
[0131] In an additional experiment X2), the reaction was carried out as described above, but with the differences that, although the autoclave was also pressurized to 40 bar with hydrogen, the mixture was stirred for 3 hours at 40 °C.
[0132] A similar yield is obtained, as shown in Table 1 below. Table 1 No. Temperature (°C) Pressure [bar] Duration [h] Efficiency [%] X1 120 40 10 99 X2 40 40 3 97
[0133] The initial substance 3-nitrophenothiazine, substance of Formula A) According to the above description of the process, it was produced in accordance with the disclosure in US 20130315825 A1.
[0134] Alternatively, 3-nitrophenothiazine can be produced by a single-step copper (Cu) catalyzed synthesis, as disclosed in WO 2017011531 A2 (p. 217). It is also possible to obtain 3-nitrophenothiazine by a non-catalyzed reaction disclosed in S. Wu, W. Hu, S. Zhang, RSC Advances, 2016, 6(29), 24257-24260. It is also possible to obtain 3-nitrophenothiazine from phenothiazine by reaction with sodium nitrite, as disclosed in WO 2007110627 A2.
[0135] Alternatively, the substance of Formula I) was obtained from 3-nitrophenothiazine in a two-step reaction according to process steps a1) to e1): Synthesis of 3-aminophenothiazine:
[0136] Under protective gas, 22 g (90.0 mmol, 1.0 eq.) of 3Petition 870260044259, dated 11 / 05 / 2026, p. 35 / 86 29 / 31 nitrophenothiazines were weighed, dissolved in 800 mL of ethanol, mixed with 102 g (534 mmol, 5.0 eq.) of tin(II) chloride dihydrate and stirred under boiling heat for 4 days. After the reaction was brought to room temperature (RT), one third of the solvent was removed by distillation and the remainder poured onto ice. Subsequently, the pH of the mixture was adjusted to pH=7 using aqueous potassium hydroxide solution and extracted three times with ethyl acetate. The organic phase was washed with saturated NaCl solution and subsequently dried with Na2SO4. A brown solid was obtained; yield 18.9 g (98% of theory). 1H-NMR (500 MHz, DMSO-d6) δ = 8.08 (s, 1H), 6.94 (td, J = 7.7, 1.5 Hz, 1H), 6.88 (dd, J = 7.7, 1.5 Hz, 1H), 6.71 - 6.60 (m, 2H), 6.46 (d, J = 8.3 Hz, 1H), 6.32 - 6.22 (m, H), 4.64 (s, 2H). ESI-MS [M+H]+ = 215. Synthesis of 3-(1,3-dimethylbutylamino)phenothiazine:
[0137] 5.00 g (23.3 mmol, 1 eq.) of 3-aminophenothiazine, 2.00 g of palladium on carbon (5%) (0.4 g in 4.67 mmol of substrate) and 50.0 mL of methyl isobutyl ketone were weighed into a stainless steel autoclave fitted with a Teflon inner lining. The autoclave was then pressurized to 40 bar with hydrogen and stirred at 120 °C for 10 hours. After the reaction was complete, the excess hydrogen was blown off and the suspension filtered through diatomaceous earth (Celite®) and washed with ethanol. The filtrate was concentrated to dryness and dried under vacuum. Grayish to violet solid; yield 6.61 g (95% of theory).
[0138] 1H-NMR (500 MHz, DMSO-d6) δ = 8.09 (s, 1H), 6.94 (td, J = 7.6, 1.5 Hz, 1H), 6.88 (dd, J = 7.6, 1.4 Hz, 1H), 6.69 - 6.63 (m, 2H), 6.51 (d, J = 8.4 Hz, 1H), 6.27 (dd, J = 8.5, 2.5 Hz, 1H), 6.21 (d, J = 2.5Hz, Petition 870260044259, dated 11 / 05 / 2026, p. 36 / 86 30 / 31 1H), 4.82 (d, J = 8.9 Hz, 1H), 3.30 (dt, J = 8.6, 6.5 Hz, 1H), 1.70 (dp, J = 13.5, 6.7 Hz, 1H), 1.38 (dt, J = 13.9, 7.1 Hz, 1H), 1.16 (dt, J = 13.5 Hz, 1H), 1.02 (dt, J = 8.6, 6.5 Hz, 1H), 1.17 (dp, J = 6.7 Hz, 1H).
[0139] 13C-NMR (126 MHz, DMSO-d6) δ = 144.5, 143.9, 131.8, 127.7, 126.6, 121.0, 117.6, 116.5, 115.8, 114.4, 112.1, 110.7, 46.5, 46.4, 25.0, 23.2, 23.0, 21.2. ESI-MS [M+H]+= 299.
[0140] Alternatively, the substance of Formula I) was obtained in a single-step reaction according to process steps a2) to c2): Synthesis of 3-(1,3-dimethylbutylamino)phenothiazine:
[0141] Under protective gas, 10 g (37.3 mmol, 1 eq.) of 6-PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) were dissolved in 80 mL of degassed o-dichlorobenzene and mixed with 2.9 g (89 mmol, 2.4 eq based on monomeric S) of sulfur and 0.95 g (3.73 mmol, 0.1 eq.) of iodine (I2). The mixture was heated under reflux (180 °C) for 4 hours. The hydrogen sulfide formed was passed to a 5% NaOH solution. Once cooled to room temperature (RT), the mixture was mixed with dichloromethane (DCM) and a saturated solution of Na2S2O3. The resulting black solid was removed by filtration and the organic phase separated from the aqueous phase. The organic phase was washed with a saturated NaCl solution and dried with Na2SO4 and concentrated to dryness. The black solid was analyzed by LC-MS (liquid chromatography-mass spectrometry) with coupled UV-VIS spectroscopy (ultraviolet and visible spectroscopy). It contained 39% (E)-N-(4 Petition 870260044259, dated 11 / 05 / 2026, page 37 / 86 31 / 31 methylpentan-2-yl)-3H-phenothiazine-3-imine as a byproduct (lower molecule on the right side of the reaction arrow) and 24% of undefined substances. The remaining 37% are composed of starting material and the inventive compound of Formula I).
[0142] The inventive compound of Formula I) exhibits high reactivity compared to 6PPD. This was consistent, for example, with the calculation of the bond dissociation energies (BDE) and the free activation enthalpy ΔRG# and the free standard reaction enthalpy ΔRGo for the reaction with a methyl peroxide radical. The values are reported in Table 2. Figs. 1a and 1b show the cleavage mechanisms to which the values refer: Table 2 Molecule BDE [kJ / mol] ΔRGo [kJ / mol] ΔRG# [kJ / mol] 6PPD 313 -25.6 19.1 Formula I) 251 -52.8 6.3 As is evident from Table 2, the inventive compound of Formula I) exhibits a lower bond dissociation energy and lower free enthalpies.
[0143] The compound of Formula I) thus makes it possible to achieve an improved protective effect in the aforementioned applications.
[0144] For use in a rubber compound for vehicle tires, the inventive compound of Formula I) is added, for example, instead of aging stabilizers known in the prior art, such as 6PPD, 7PPD or IPPD etc., in a manner known to those skilled in the art in one of the mixing steps in the production of the rubber compound.
Claims
1. Compound, characterized by the fact that it has Formula (I): (I) 2. Rubber mixture, characterized in that it contains the compound of Formula (I), as defined in claim 1.
3. Rubber mixture according to claim 2, characterized in that it contains at least one diene rubber.
4. Rubber mixture according to claim 3, characterized in that it contains at least one diene rubber selected from the group consisting of 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 halobutyl rubber.
5. Vehicle tire, characterized in that it comprises a rubber mixture, as defined in any one of claims 2 to 4, in at least one component.
6. Vehicle tire, according to claim 5, characterized in that it contains at least one rubber compound, as defined in any one of claims 2 to 4, in at least one external component, wherein the external component is a tread, a sidewall and / or a flange profile.
7. Process for producing the compound of Formula (I), as defined in claim 1, characterized in that it comprises at least the following process steps: Petition 870260044259, dated 11 / 05 / 2026, page 39 / 86 2 / 4 (a) providing the substance of Formula (A), (A) (H2); (b) (c) providing methyl isobutyl ketone (MIBK) and hydrogen reacting the substance according to step (a) with the substances according to step (b) to generate the substance of Formula (I), (I) 8. Process for producing the compound of Formula (I), as defined in claim 1, characterized in that it comprises at least the following process steps: (a1) providing the substance of Formula (A), (A) (b1) providing a reducing agent, or tin(II) chloride dihydrate; (c1) reacting the substance according to step (a1) with the substance of step (b1) to generate the substance of Formula (C1), (C1) (d1) providing methyl isobutyl ketone (MIBK) and hydrogen (H2); (e1) reacting the substance of Formula (C1) with the substances Petition 870260044259, dated 11 / 05 / 2026, p. 40 / 86 3 / 4 according to step (d1) to generate the substance of Formula (I), (I) 9. Process for producing the compound of Formula (I), as defined in claim 1, characterized in that it comprises at least the following process steps: (a2) providing the substance of Formula (A2); (b2) providing elemental sulfur and o-dichlorobenzene; (c2) reacting the substance according to step (a2) with the substances according to step (b2) to generate the substance of Formula (I).
10. Use of the compound of Formula (I), as defined in claim 1, characterized in that it is used as an aging stabilizer and / or antiozonant in vehicle tires and / or technical rubber articles.
11. Use of the compound of Formula (I), as defined in claim 1, characterized in that it is in oils and lubricants. Petition 870260044259, dated 11 / 05 / 2026, page 41 / 86 4 / 4 12. Use of the compound of Formula (I), as defined in claim 1, characterized in that it is as a dye in fibers and / or polymers and / or paper.