Method of preparing hydrogenation catalyst

Abstract

To provide a catalyst composition, and a device and method for preparing the same.SOLUTION: A method of forming a hydrogenation catalyst includes providing a first fluid including a first reagent to a first reagent dispensing device, the first reagent including an organoaluminum compound and providing a second fluid including a second reagent to a second reagent dispensing device, the second reagent including a nickel alkoxylate. The method further includes simultaneously delivering the first fluid from the first reagent dispensing device and the second fluid from second reagent dispensing device to a reaction vessel at a constant stoichiometry of aluminum in the organoaluminum compound to nickel in the nickel alkoxylate, the organoaluminum compound reacting with the nickel alkoxylate in the reaction vessel to form the hydrogenation catalyst.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001]

[0001] The embodiments disclosed herein relate to a method for preparing and using a hydrogenation catalyst particularly applicable in the partial hydrogenation of unsaturated elastomers used in rubber compositions.

Background Art

[0002]

[0002] Hydrogenation catalysts are often used in the chemical modification of natural rubber and other unsaturated elastomers. This can help to impart higher stability to the elastomers against heat, oxidative, and radiation-induced degradation. One commonly used catalyst system is a homogeneous Ziegler-Natta catalyst formed by the reaction of a trialkylaluminum compound with a nickel alkylcarboxylate such as nickel 2-ethylhexanoate or nickel(II) octanoate. The reaction can be carried out in a suitable solvent such as hexane. The ratio of aluminum to nickel in the cocatalyst system is selected to provide active catalyst species while avoiding excess alkylaluminum that can interact with the active species to yield inactive products. See, for example, Gan et al., “Hydrogenation of Natural Rubber Using Nickel 2-Ethylhexanoate Catalyst in Combination with Triisobutylaluminum”, J. Applied Polymer Science, Vol. 59, pp. 63-70 (1996). In Gan's method, triisobutylaluminum is added to nickel 2-ethylhexanoate in a reaction vessel containing a natural rubber sample in hexane. The reaction vessel is pressurized with hydrogen gas. U.S. Patent Application Publication No. 2021 / 0340306A1 to Yukimura et al. describes the hydrogenation of a functionalized copolymer with the addition of nickel octanoate following the addition of triethylaluminum. In both the methods of Gan and Yukimura, an Al:Ni ratio of about 3:1 has been found to be effective.

[0003]

[0003] One problem with existing methods for preparing such hydrogenation catalysts is that adding a nickel compound to an aluminum compound, or vice versa, causes the Al:Ni ratio to vary throughout the reaction. This can lead to deactivation of the catalyst system or a shortage of active species. Furthermore, long-term storage of such catalyst systems is generally not feasible.

[0004]

[0004] Next, catalyst compositions that can address these and other problems, as well as apparatuses and methods for preparing the same, will be described.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Non-Patent Documents

[0006]

Non-Patent Document 1

Summary of the Invention

Means for Solving the Problems

[0007]

[0005] According to an exemplary embodiment, a method of forming a hydrogenation catalyst includes providing a first fluid containing a first reagent including an organoaluminum compound to a first reagent dispensing device, and providing a second fluid containing a second reagent including nickel alkoxide to a second reagent dispensing device. The method further includes simultaneously delivering the first fluid from the first reagent dispensing device and the second fluid from the second reagent dispensing device to a reaction vessel, delivering in a certain stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxide, and the organoaluminum compound reacts with the nickel alkoxide in the reaction vessel to form a hydrogenation catalyst.

[0008]

[0006] In various aspects of this embodiment,

[0007] At least one of the first fluid and the second fluid may further include a solvent. The solvent may be selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, cycloaliphatic hydrocarbons, and mixtures thereof. The solvent may be selected from the group consisting of hexane, pentane, toluene, benzene, cyclohexane, and mixtures thereof.

[0009]

[0008] The organoaluminum compound has the formula I:

[0010]

Chemical formula

[0011] (wherein R 1 is selected from alkyl, alkoxy, aryl, aralkyl, arylalkyl, and hydrogen, and R 2 is selected from alkyl (including cycloalkyl), aryl, aralkyl, arylalkyl, and hydrogen, and R 3(selected from alkyl (including cycloalkyl), aryl, alkaryl and arylalkyl) may be represented by

[0012]

[0009] The organoaluminum compound may contain a trialkylaluminum compound. In the trialkylaluminum compound, R 1 , R 2 and R 3 may each independently be a C1-C18 straight-chain or branched alkyl group. The trialkylaluminum compound may be selected from the group consisting of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, and their dimers and mixtures.

[0013]

[0010] The nickel alkoxylate may be derived from a C6-C18 carboxylic acid. The nickel alkoxylate may be selected from the group consisting of nickel(II) octylate and nickel octanoate.

[0014]

[0011] A certain stoichiometry between aluminum in the organoaluminum compound and nickel in the nickel alkoxylate may be fixed within the range of 2:1 to 3.5:1, or up to 3:1.

[0015]

[0012] The step of simultaneously delivering the first fluid from the first reagent dispensing device and the second fluid from the second reagent dispensing device to the reaction vessel may include maintaining a certain stoichiometry between aluminum in the organoaluminum compound and nickel in the nickel alkoxylate for at least 2 minutes, or at least 10 minutes, or at least 30 minutes.

[0016]

[0013] The first reagent dispensing device and the second reagent dispensing device may each include a syringe actuated by a respective motor or a common motor.

[0014] Delivery may include pumping the first and second fluids to a mixing point upstream of the reaction vessel and delivering a mixture of the first and second fluids from the mixing point to the reaction vessel.

[0017]

[0015] The reaction vessel may be cooled during the reaction.

[0016] The hydrogenation catalyst may be formed by the method according to any of the above aspects.

[0017] The rubber composition may include a hydrogenated elastomer hydrogenated with the above-described hydrogenation catalyst and at least one additive selected from the group consisting of a filler, a plasticizer, zinc oxide, and a sulfur-based curing agent.

[0018]

[0018] According to another embodiment, in the combination, the apparatus and reagents for forming the hydrogenation catalyst include a first reagent dispensing device including a first reagent containing an organoaluminum compound, and a second reagent dispensing device including a second reagent containing a nickel alkoxide. The first delivery tube connects the first reagent dispensing device to the mixing point. The second delivery tube connects the second reagent dispensing device to the mixing point. The common delivery tube connects the mixing point to the reaction vessel. The pressurizing mechanism pressurizes the first and second reagents so that they are delivered to the reaction vessel in a certain stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxide.

[0019]

[0019] In various aspects of this embodiment,

[0020] The first and second reagent dispensing devices may include first and second syringes.

[0020]

[0021] The pressurizing mechanism may include a motor that drives a plunger of at least one of the first and second syringes.

Brief Description of the Drawings

[0021]

Figure 1

[0022] It is a side cross-sectional view of one embodiment of an apparatus for preparing a hydrogenation catalyst.

Figure 2

[0023] It is a flowchart showing a method for preparing a hydrogenation catalyst.

Embodiments for Carrying Out the Invention

[0022]

[0024] Aspects of the exemplary embodiments relate to a hydrogenation catalyst, an apparatus for preparing a hydrogenation catalyst, a process for preparing a hydrogenation catalyst, and a hydrogenation method using the catalyst.

[0025] The hydrogenation catalyst can be used for the partial or complete hydrogenation of unsaturated hydrocarbons such as alkenes and unsaturated elastomers such as those used in rubber compositions. The hydrogenation catalyst can have excellent activity and storage stability compared to existing hydrogenation catalysts formed by the reaction of a trialkylaluminum compound and a nickel alkoxide compound. Further, the catalyst can act outside the range of the previously used Ni:Al ratio.

[0023]

[0026] In the exemplary apparatus and method, the organoaluminum compound reacts with the nickel alkoxide to form a complex in which nickel-containing particles of extremely small size (and thus having a high active surface area) are dispersed in a gel in which aluminum is concentrated.

[0024]

[0027] Examples of nickel alkoxides include those derived from C6 - C18 carboxylic acids, such as nickel(II) octylate (which is bis(2-ethylhexanoic acid) nickel) and nickel octanoate.

[0025]

[0028] The organoaluminum compound contains at least one carbon-aluminum bond and has the formula I:

[0026]

Chemical formula

[0027] (In the formula, R 1 is selected from alkyl (including cycloalkyl), alkoxy, aryl, aralkyl, arylalkyl and hydrogen, and R 2 is selected from alkyl (including cycloalkyl), aryl, aralkyl, arylalkyl and hydrogen, and R 3 is selected from alkyl (including cycloalkyl), aryl, aralkyl and arylalkyl). It can be represented by

[0028]

[0029] In one embodiment, R 1 and R 2 are not hydrogen.

[0030] In one embodiment, R 1 , R 2 and R 3 are each an alkyl group, that is, the organoaluminum compound is a trialkylaluminum compound.

[0029]

[0031] In one embodiment, at least one of R 1 , R 2 and R 3 , R 1 , R 2 and R 3 has beta hydrogen.

[0032] Typical trialkylaluminum compounds include R 1 , R 2 and R 3Each is independently a C1-C18 linear or branched alkyl group, or a C1-C12 linear or branched alkyl group. Examples include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, and mixtures thereof. The trialkylaluminum compound can exist in the form of a monomer or a dimer, or a mixture thereof. In one embodiment, the trialkylaluminum compound contains triisobutylaluminum.

[0030]

[0033] Representative aryl and alkylaryl organoaluminum compounds include triphenylaluminum, tri-p-tolylaluminum, tribenzylaluminum, ethyldiphenylaluminum, ethyl-di-p-tolylaluminum, ethyldibenzylaluminum, diethylphenylaluminum, diethyl-p-tolylaluminum, diethylbenzylaluminum, and mixtures thereof.

[0031]

[0034] R 1 Other representative organoaluminum compounds where R is hydrogen include diethylaluminum hydride, di-n-propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, p-tolylethylaluminum hydride, p-tolyl-n-propylaluminum hydride, p-tolylisopropylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, and benzylisopropylaluminum hydride, and mixtures thereof. R 1 and R 2Other typical organoaluminum compounds in which the hydrogen is hydrogen include ethylaluminum dihydride, butylaluminum dihydride, isobutylaluminum dihydride, octylaluminum dihydride, amylaluminum dihydride, and mixtures thereof. Also included are diethylaluminum ethoxide and dipropylaluminum ethoxide.

[0032]

[0035] The reaction of reagents (e.g., nickel(II) octoate and triisobutylaluminum) to form a hydrogenation catalyst may be carried out in a suitable solvent in a reaction vessel. The reagents may be maintained in a certain stoichiometry through the catalyst preparation. "A certain stoichiometry" means that the molar ratio of nickel in nickel alkoxide in the reaction vessel to aluminum in the organoaluminum compound does not vary by more than ±10% or more than ±5% during the preparation of the hydrogenation catalyst. While the reaction is taking place, the two reagents may be introduced into the reaction vessel simultaneously at a predetermined flow rate so that the reagents in the reaction vessel are continuously replenished in a certain stoichiometry. This can be achieved using a suitable pressurization mechanism such as a motor-driven pump or other mechanism for controlling the flow rates of both reagents through a tube, ensuring the maintenance of a certain stoichiometry. In one embodiment, the pump is a syringe pump, but other pumps such as gear pumps, screw pumps, peristaltic pumps, rotary pumps, etc. are also contemplated provided that a certain stoichiometry can be ensured. In other embodiments, the flow rate may vary during the reaction while maintaining a certain stoichiometry, for example, through a gravity flow mechanism.

[0033]

[0036] During the preparation of the hydrogenation catalyst, the process of maintaining a certain stoichiometry between nickel and aluminum has been found to result in higher activity and better storage stability than when one of the reagents is placed in the reaction vessel and the other is introduced later. Furthermore, the Al:Ni molar ratio maintained during the reaction may be associated with higher activity and may be outside the range of previously disclosed and accepted ratios and outside the previously established boundaries.

[0034]

[0037] In one embodiment, the Al:Ni molar ratio of the reagents entering the reaction vessel is maintained at a constant value in the range of 1.5:1 to 3.5:1, or in the range of 2.3:1 to 2.5:1 throughout the addition.

[0038] The solvent used in the reaction may be any organic solvent in which the two reagents (organoaluminum compound and nickel alkoxide) are soluble. Further, in an exemplary embodiment, the hydrogenation catalyst formed in the reaction remains dispersed in the solvent during subsequent use and may thus be selected to be compatible with the elastomer to be hydrogenated. Exemplary solvents include aprotic organic solvents such as aliphatic, aromatic and cycloaliphatic hydrocarbons such as hexane, pentane, toluene, benzene, cyclohexane and mixtures thereof.

[0035]

[0039] FIG. 1 shows an exemplary apparatus 10 for preparing a hydrogenation catalyst. A reaction vessel 12, such as a flask, has an open end 14 for receiving two reagents. A first reagent delivery device, such as a syringe pump 16, includes a first barrel 18 that holds a first fluid A containing a first reagent (e.g., an organoaluminum compound) optionally dissolved or dispersed in a suitable solvent such as hexane. A first plunger 20 extrudes the first fluid A containing the first reagent from the first barrel 18 through a first outlet 22 into a first delivery tube 24. The first plunger 20 is advanced by a first motor 26, such as a first stepper motor, while the first barrel is maintained in a fixed position. A second reagent delivery device configured similarly, such as a syringe pump 28, includes a second barrel 30 that holds a second fluid B containing a second reagent (e.g., nickel alkoxide) optionally dissolved or dispersed in a suitable solvent such as hexane or a different solvent. A second plunger 32 extrudes the fluid B containing the second reagent from the second barrel 30 through a second outlet 34 into a second delivery tube 36. The second plunger 32 is advanced by a second motor 38, such as a second stepper motor, while the second barrel is maintained in a fixed position. In another embodiment (not shown), the plungers 20, 32 may be driven by a common motor. The motors may be under the control of a common controller 40 as shown, or may be controlled separately. A fixed ratio is defined by the flow rate and concentration of the reagents within the syringes. Alternatively, the motors are manually adjusted to provide a fixed delivery amount. As will be appreciated, pressurization mechanisms other than the illustrated motors are contemplated to pressurize the first and second reagents so that they are delivered to the reaction vessel in a fixed stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxide.

[0036]

[0040] In the illustrated embodiment, the first and second delivery tubes 24, 36 are connected at a mixing point 42, such as a T-shaped junction, located upstream of the flask 12 so that the mixture of the first and second reagents enters the flask through a common delivery tube 44. In another embodiment (not shown), the first and second reagents A, B are delivered to the flask through completely separate tubes and are mixed only within the flask 12.

[0037]

[0041] The mixture 46 of the reagents and their reaction products within the flask 12 may be maintained at a reaction temperature suitable for forming a hydrogenation catalyst, such as less than about 50 °C, or less than about 40 °C, while avoiding decomposition of the reaction products, for example by use of a cooling jacket 48.

[0038]

[0042] The reaction may be carried out under an inert gas such as nitrogen. For example, a suitable gas delivery system represented by tubes 50, 52 flushes the flask with nitrogen before and / or during introduction of the reagents.

[0039]

[0043] Before starting the motors 26, 28, the reagent delivery devices 16, 18 may be isolated from each other upstream of the mixing point 42, for example by valves 54, 56 which may be positioned within their respective delivery tubes 24, 36 or at the outlets 22, 24 of the delivery devices 16, 28. The valves may be under the control of a controller 40 such that the valves are opened immediately prior to activating the motors 26, 38.

[0040]

[0044] The reaction products formed within the flask are collected and may be stored for several weeks or in some cases up to one month or more before use in the hydrogenation of elastomers without significant loss of activity. The storage stability is a significant advantage over similar hydrogenation catalysts which rapidly lose activity. Such existing catalysts may be prepared by conventional processes in which one reagent is added to the other, resulting in a change in the stoichiometry of the metal through the reaction.

[0041]

[0045] Another advantage over existing catalysts is that the activity of the catalyst at a given temperature is higher than that of existing catalysts containing the same amount of nickel in molar units. Therefore, the hydrogenation catalyst of the present invention can be used in a smaller amount, and / or for a shorter time, and / or at a lower temperature to achieve the desired level of hydrogenation as an existing catalyst. The ability to hydrogenate elastomers at lower temperatures and / or times has advantages in some cases, such as when the elastomer is functionalized in parts where it tends to decompose or crosslink. The ability to hydrogenate elastomers with a smaller amount of catalyst can result in significant cost savings and may be more environmentally desirable. The ability to hydrogenate elastomers in a shorter time (about 1 / 4 or less of the time is observed for an equivalent amount of nickel at the same reaction temperature) allows for the production of hydrogenated elastomers at a faster rate and saves time and operating costs.

[0042]

[0046] Figure 2 shows a method for preparing a hydrogenation catalyst. The method starts at S100.

[0047] In S102, a first fluid containing a first reagent such as an organoaluminum compound is provided to a first reagent delivery device such as a first syringe. The first reagent may be dissolved in an organic solvent such as hexane at a reagent: solvent weight ratio of, for example, 50:50 to 75:25, for example, about 65:35.

[0043]

[0048] In S104, a second fluid containing a second reagent such as nickel alkoxide is provided to a second reagent delivery device such as a second syringe separately from the first reagent. The second reagent may be dissolved in an organic solvent such as hexane at a reagent: solvent weight ratio of, for example, 50:50 to 75:25, for example, about 65:35.

[0044]

[0049] In S106, a portion of an inert solvent such as hexane may be introduced into the reaction vessel and flushed with an inert gas such as nitrogen.

[0050] In S108, the reaction vessel may be heated to a temperature suitable for the reaction to occur between the reagents.

[0045]

[0051] In S110, a first fluid containing a first reagent is continuously delivered under pressure from a first reagent delivery device to a reaction vessel over a certain period, during which a second fluid containing a second reagent is simultaneously continuously delivered under pressure from a second reagent delivery device to the reaction vessel, maintaining a certain molar ratio of the first and second reagents. The dispensing may be continuous, for example, for a period of at least 2 minutes, or at least 5 minutes, or at least 30 minutes, or for a time sufficient to maintain the reaction temperature in the reaction vessel below about 40°C, for an exemplary 500 ml batch.

[0046]

[0052] In S112, the first and second reagents are reacted together in the reaction vessel to form a hydrogenation catalyst.

[0053] In S114, the hydrogenation catalyst may be stored in the reaction vessel until needed for the hydrogenation process or may be transferred to a separate storage container. After completion of the reaction, there is no need to further process the catalyst, such as separating the catalyst from the solvent. The catalyst may be mixed with the solvent and used in the form of a gel.

[0047]

[0054] The method ends in S116.

[0055] The reaction product is a colloidal mixture of small particles of nickel dispersed in an aluminum-containing gel. The nickel metal (nickel(0)) particles are much smaller and of uniform size (less than 10 nanometers on average) than can be achieved with existing preparation methods that do not use a fixed stoichiometry. These small particles provide a high surface area that results in a hydrogenation catalyst that is very effective for the hydrogenation of unsaturated elastomers.

[0048]

[0056] The hydrogenation catalyst described in this specification can be used for the hydrogenation of one or more polydiene elastomers containing unsaturation in the form of double bonds. Such elastomers are polymers derived from conjugated diene monomers, such as butadiene, and optionally one or more other monomers, such as vinyl aromatic monomers, such as styrene. The elastomer may contain at least 40%, or at least 90%, or at least 92% of cis 1,4 microstructure in the polydiene portion of the elastomer.

[0049]

[0057] For example, the elastomer may be a homopolymer formed from 1,3-butadiene monomer (polybutadiene, PBD), or a copolymer formed from a mixture of 1,3-butadiene monomer and styrene (styrene-butadiene rubber SBR, SSBR that can be formed by solution polymerization, or ESBR that can be formed by emulsion polymerization), and / or other polydiene-based elastomers. Examples of elastomers that can be hydrogenated using an exemplary hydrogenation catalyst include polybutadiene rubber, styrene / butadiene rubber, styrene / isoprene / butadiene rubber, butadiene / acrylonitrile rubber, styrene / butadiene / acrylonitrile rubber, methyl methacrylate / butadiene / styrene rubber, and polymers derived from substituted butadienes, such as methylbutadiene or dimethylbutadiene, pentadiene, etc.

[0050]

[0058] The elastomer to be hydrogenated may be functionalized at the ends, for example, as described in U.S. Patent Application No. 18 / 155,927 entitled "FUNCTIONALIZED HYDROGENATED POLYMERS", 18 / 155,835 entitled "FUNCTIONALIZED HYDROGENATED POLYMERS", 18 / 155,799 entitled "FUNCTIONALIZED HYDROGENATED POLYMERS", and 18 / 155,815 entitled "HYDROGENATED POLYMERS WITH SILOXYTRITHIOCARBONATE TERMINATION" (all filed on January 18, 2023). Functionalization may also occur in the middle of the ends. In another embodiment, the elastomer is functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of a primary amine and a thiol, optionally. For example, the (co)polymer chain of a conjugated diene or a conjugated diene and an aromatic vinyl compound may be terminated with a terminator compound having a protected primary amino group and an alkoxysilyl group, as described in, for example, U.S. Patent No. 7,342,070. Another SBR functionalized with an alkoxysilane group and a thiol is described in U.S. Patent Application Publication No. 20080287601A1.

[0051]

[0059] The hydrogenation of the polydiene elastomer may be partial or complete. By partial is meant that fewer than all of the double bonds present in the polydiene segments of the elastomer are hydrogenated by the catalyst. For example, at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 60%, or at least 80% of the double bonds present in the polydiene segments of the elastomer are saturated by hydrogenation. In some embodiments, up to 100% of the double bonds present in the polydiene segments of the elastomer are saturated by hydrogenation.

[0052]

[0060] Partially or fully hydrogenated elastomers may be used in the rubber composition. The rubber composition is formed from components that in total contain 100 parts of elastomeric components. The total amount of 100 parts of elastomer or rubber is used such that the amounts of the other components can be listed in terms of parts per hundred parts by weight (phr) of rubber (or 100 parts of elastomeric components). The elastomeric components include hydrogenated elastomers with optional use of other elastomers, such as natural rubber, and synthetic polymers, such as polyisoprene (including cis-1,4-polyisoprene), and copolymers formed from butadiene or homologs or derivatives thereof and other unsaturated monomers. Among the latter are acetylenes, such as vinylacetylene; olefins, such as isobutylene which copolymerizes with isoprene to form butyl rubber; vinyl compounds, such as acrylic acid, acrylonitrile (which polymerizes with butadiene to form NBR), methacrylic acid, vinyl esters, and various unsaturated aldehydes, ketones, and ethers, such as acrolein, methyl isopropenyl ketone, and vinyl ethyl ether. Other elastomers include halogen-containing elastomers, such as neoprene (polychloroprene), halobutyl rubbers, such as chlorobutyl rubber and bromobutyl rubber; ethylene / propylene terpolymers, especially ethylene / propylene / dicyclopentadiene terpolymers, also known as ethylene / propylene / diene monomer (EPDM); alkoxy-silyl end-functionalized solution polymerization polymers (SBR, PBR, IBR, and SIBR), silicon coupling and tin coupling star-branched polymers, and combinations thereof.

[0053]

[0061] The weight ratio of the hydrogenated elastomer to the other elastomers when used can be from 5:95 to 99:1, or from 10:90 to 90:10.

[0062] The rubber composition may contain one or more fillers such as silica and / or carbon black, optionally an organosilane coupling agent, a plasticizer such as oil and / or resin, optionally a wax, a sulfur-based curing agent, one or more curing activators such as zinc oxide and / or an organic curing activator, an accelerator, and optionally a curing inhibitor, a free radical initiator, an antioxidant, an ozone degradation inhibitor, a peptizer, and one or more additional additives.

[0054]

[0063] Silica, such as precipitated silica, may be used in the rubber composition in an amount of at least 5 phr and / or a maximum of 160 phr. The silica has a CTAB specific surface area of at least 120 m 2 / g, or at least 140 m 2 / g, or a maximum of 400 m 2 / g, or a maximum of 300 m 2 / g, or a maximum of 230 m 2 / g. The CTAB surface area is measured according to ASTM D6845-20, "Standard Test Method for Silica, Precipitated, Hydrated - CTAB (Cetyltrimethylammonium Bromide) Surface Area".

[0055]

[0064] When carbon black is used, it may be present in the rubber composition in an amount of at least 2 phr and / or a maximum of 60 phr. The carbon black has a specific surface area of at least 8 m 2 / kg, or at least 20 m 2 / kg, or at least 100 m 2 / kg, or at least 120 m 2 / kg, or a maximum of 132 m 2 / kg, as determined according to ASTM D6556-21, "Standard Test Method for Carbon Black - Total and External Surface Area by Nitrogen Adsorption".

[0056]

[0065] Other particulate fillers that can be used in the rubber composition include alumina, aluminum hydroxide, clay (reinforcing grade), magnesium hydroxide, boron nitride, aluminum nitride, titanium dioxide, and combinations thereof. When such particulate fillers are used, they may be present in a total amount of 1 to 30 phr, or up to 20 phr, or up to 10 phr, or up to 5 phr.

[0057]

[0066] When used, the organosilane coupling agent aids in the dispersion of silica and the bonding of silica to the elastomer. The amount of the organosilane coupling agent in the rubber composition may depend on the amount of silica used in the rubber composition. For example, the weight ratio of the coupling agent to silica may be from 2:100 to 10:100. The amount of the organosilane coupling agent may be, for example, at least 2 phr, or at least 5 phr, or up to 16 phr, or up to 10 phr.

[0058]

[0067] Examples of organosilane coupling agents include those containing groups such as alkylalkoxy, mercapto, blocked mercapto, sulfide-containing (e.g., monosulfide-based alkoxy-containing, disulfide-based alkoxy-containing, tetrasulfide-based alkoxy-containing), amino, vinyl, epoxy, and combinations thereof. Specific examples include 3-octanoylthio-1-propyltriethoxysilane; the reaction product of a hydrocarbon diol (e.g., 2-methyl-1,3-propanediol) and S-[3-(triethoxysilyl)propyl]thiooctanoate; and bis(trialkoxysilylorgano)polysulfides including bis(3-triethoxysilylpropyl)polysulfide having an average of 2 to 4 connecting sulfur atoms in the polysulfide crosslink.

[0059]

[0068] The process oil, when used, may be at least 2 phr, or at least 3 phr, or at least 4 phr, or up to 15 phr, or up to 12 phr, or up to 10 phr, or up to 6 phr, and may be selected from aromatic oils, paraffinic oils, naphthenic oils, vegetable oils, and mixtures thereof.

[0060]

[0069] The resin, when used, may be at least 5 phr, or at least 10 phr, or at least 20 phr, or up to 90 phr, or up to 70 phr. Unlike oils that are liquid at room temperature (20 - 25 °C), resins are generally solid or highly viscous at room temperature. For example, the resin may have a glass transition temperature (Tg) of at least 40 °C, or at least 50 °C, or up to 70 °C, as determined using DSC according to ASTM D6604. Examples of resins include hydrocarbon traction resins and tackifying resins. Hydrocarbon traction resins include C5 resins containing polydicyclopentadiene (DCPD) and their hydrogenated equivalents such as HC5 resin and hydrogenated DCPD resin (HDCPD); their hydrogenated equivalents such as C9 resins and HC9 resins; and copolymers such as C5 / C9 resins containing DCPD / C9 resins, HDCPD / C9 resins, and mixtures thereof. In the abbreviations, H indicates that the resin is at least partially hydrogenated, and C5 and C9 indicate the number of carbon atoms in the monomer from which the resin is formed, before dimerization or functionalization. Other hydrocarbon traction resins that may be used include terpene - phenol resins, terpene resins, terpene - styrene resins, styrene / alpha - methylstyrene resins, and coumarone - indene resins. The resin may be at least partially hydrogenated. Examples of tackifying resins include gum rosin and its modified derivatives.

[0061]

[0070] The wax, when used, may be present at 1 - 5 phr, or up to 3 phr. Exemplary waxes include paraffin wax, microcrystalline wax, and mixtures thereof.

[0062]

[0071] The sulfur-based curing agent may be used in an amount of 0.1 to 10 phr, for example at least 0.4 phr, or at most 5 phr, or at most 2 phr. Examples of suitable sulfur-based curing agents include elemental sulfur (free sulfur), insoluble polymeric sulfur, soluble sulfur, and sulfur-donating vulcanizing agents such as amine disulfides, polymeric polysulfides, or sulfur olefin adducts, and mixtures thereof.

[0063]

[0072] The curing accelerator and activator act as a catalyst for the sulfur-based curing agent. The curing accelerator is used to control the time and / or temperature required for vulcanization and to improve the properties of the cured rubber composition. The amount of the curing accelerator may be 0.1 to 10 phr, or at least 0.5 phr, or at least 2 phr, or at most 8 phr, or at most 6 phr.

[0064]

[0073] Examples of accelerators include thiazole curing accelerators such as 2-mercaptobenzothiazole and 2,2'-dithiobis(benzothiazole) (MBTS); guanidine curing accelerators such as diphenylguanidine (DPG); sulfenamide curing accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide (CBS) and N-tert-butyl-2-benzothiazole sulfenamide (TBBS); ultra-accelerators such as 1,6-bis(N,N'-dibenzylthiocarbamoyldithio)hexane (BDBZTH); and combinations thereof.

[0065]

[0074] Zinc oxide acts as an inorganic curing activator and may be used in an amount of at least 2 phr and / or at most 10 phr.

[0075] Examples of organic hardening activators include stearic acid, palmitic acid, lauric acid, mixtures thereof, the respective zinc salts described above, and thiourea compounds such as thiourea, and dihydrocarbylthioureas such as dialkylthiourea and diarylthiourea, and mixtures thereof. The total amount of the organic hardening activator such as the mixture of fatty acids may be 0.1 to 8 phr, for example at least 0.5 phr, or at least 1 phr, or at least 2 phr, or may be up to 6 phr.

[0066]

[0076] The rubber composition contains an elastomer, a filler, and other rubber compounding ingredients excluding the curing agent, and is mixed in at least one sequential mixing stage or a plurality of stages using at least one mechanical mixer, which is usually called the "non-productive" mixing stage, under high-shear rubber mixing conditions up to a high temperature (for example, 130°C to 200°C), and then in the final "productive" mixing stage, a sulfur-based curing package such as a sulfur-based curing agent and a curing accelerator is added to the mixture, and in order to avoid unnecessary pre-curing of the rubber mixture during the productive mixing stage, it is followed by a stage of mixing at a lower mixing temperature (for example, less than 120°C). The mixing may be carried out, for example, by kneading the components together on a Banbury mixer or a mill roll. The rubber composition may be cooled to a temperature below 40°C between each of the mixing stages.

[0067]

[0077] Once the curing package is sufficiently mixed into the rubber composition, the rubber composition can be molded or otherwise formed into the shape of a green component of a tire, such as a tire tread or an inner liner. The temperature of the green component can be raised to effect curing. Curing of a pneumatic tire or a part thereof may be carried out at a temperature of 120°C to 200°C, for example at least 140°C, or at most 180°C, or about 150°C for at least 10 minutes. Any of the usual vulcanization processes may be used, such as heating with a press or a mold, or heating with superheated steam or hot air. Such tires may be constructed, shaped, molded, and cured by various known methods, which will be readily apparent to those skilled in such technical fields.

[0068]

[0078] In one embodiment, a tire is provided, the tire having a tread formed, at least in part, from an exemplary rubber composition formed using a hydrogenated elastomer described herein. Other parts of the tire, such as the sidewall and inner liner of the tire, may additionally or alternatively be formed, at least in part, from the rubber composition described herein. The tire may be a pneumatic tire for on-road vehicles such as buses or trucks or automobiles, or a tire for off-road vehicles, airplanes, etc. The rubber composition is not limited to use in tires and may be applied to rubber gloves, hoses, surgical instruments, etc.

[0069]

[0079] There are several advantages to hydrogenating an elastomer. By reducing the number of double bonds, the opportunity for the rubber product to deteriorate is reduced. Ozone-induced deterioration tends to reduce the molecular weight of the polymer, while oxidation of the polymer at allylic sites leads to hardening. By reducing the number of double bonds, the durability of the resulting product is improved. Another advantage of reducing the number of double bonds is an increase in the tensile strength of the rubber composition. For example, the tensile strength may increase by about 50%. Improvement in tire tread wear may also occur.

[0070]

[0080] Each of the documents referred to above is incorporated herein by reference. Singular forms such as "a" and "an" are intended to include the plural unless the context indicates otherwise. Unless otherwise indicated by way of example or explicitly stated, all numerical values in this specification that specify amounts of materials, reaction conditions, molecular weights, numbers of carbon atoms, etc. are to be understood as being modified by the term "about". Unless otherwise indicated, each chemical substance or composition referred to in this specification is to be construed as a commercially available grade of material that may include isomers, by-products, derivatives, and other such materials that are understood to be present in commercially available grades. However, the amounts of each chemical constituent are shown excluding solvents or diluent oils that may customarily be present in commercially available materials, unless otherwise indicated. It should be understood that the upper and lower limits of the amounts, ranges, and ratios described herein can be combined independently. Similarly, the ranges and amounts of each element of the present invention may be used in combination with any of the ranges or amounts of other elements.

[0071]

[0081] It is understood that the above-disclosed, as well as variations of other features and functions or alternatives thereto, can be combined in many other different systems or applications. Various presently unforeseen or unexpected alternatives, modifications, variations, or improvements may later be made by those skilled in the art, but these are also intended to be encompassed by the following claims.

Description of the Reference Signs

[0072] 10 Device 12 Reaction Vessel 14 End 16 Syringe Pump 18 First Barrel 20 First Plunger 22 First Outlet 24 First Delivery Tube 26 First Motor 28 Syringe Pump 30 Second Barrel 32 Second Plunger 34 Second Outlet 36 Second Delivery Tube 38 Second motor 40 Controller 42 Mixing point 44 Delivery pipe 46 Mixture 48 Cooling jacket 50 Pipe 52 Pipe 54 Valve 56 Valve A First fluid B Second fluid

Claims

1. providing a first fluid to a first reagent-dispensing device, the first fluid comprising a first reagent comprising an organoaluminum compound; providing a second fluid to a second reagent-dispensing device, the second fluid comprising a second reagent comprising a nickel alkoxylate; Simultaneously delivering a first fluid from a first reagent-dispensing device and a second fluid from a second reagent-dispensing device to a reaction vessel, the first fluid being delivered at a fixed stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxylate, the organoaluminum compound reacting with the nickel alkoxylate in the reaction vessel to form a hydrogenation catalyst.

2. A method for forming a hydrogenation catalyst comprising:

2. The method of claim 1 , wherein at least one of the first fluid and the second fluid further comprises a solvent.

3. 3. The method of claim 2, wherein the solvent is selected from the group consisting of aliphatic hydrocarbons, aromatic hydrocarbons, cycloaliphatic hydrocarbons, and mixtures thereof.

4. 3. The method of claim 2, wherein the solvent is selected from the group consisting of hexane, pentane, toluene, benzene, cyclohexane, and mixtures thereof.

5. The organoaluminum compound is represented by formula I: 【Chemistry 1】 (In the formula, R １ is selected from alkyl, alkoxy, aryl, alkaryl, arylalkyl, and hydrogen; R ２ is selected from alkyl (including cycloalkyl), aryl, alkaryl, arylalkyl, and hydrogen; R ３ is selected from alkyl (including cycloalkyl), aryl, alkaryl and arylalkyl; The method of claim 1 , wherein the method is represented by:

6. The method of claim 5, wherein the organoaluminum compound comprises a trialkylaluminum compound.

7. In the trialkylaluminum compound, R １ , R ２ and R ３ The method of claim 6, wherein each is independently a C1 to C18 straight chain or branched alkyl group.

8. 7. The method of claim 6, wherein the trialkylaluminum compound is selected from the group consisting of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, and dimers and mixtures thereof.

9. 2. The method of claim 1, wherein the nickel alkoxylate is derived from a C6 to C18 carboxylic acid.

10. 2. The method of claim 1, wherein the nickel alkoxylate is selected from the group consisting of nickel (II) octoate and nickel octoate.

11. 2. The process of claim 1, wherein a constant stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxylate is fixed within the range of 2:1 to 3.5:

1.

12. 2. The method of claim 1, wherein the step of simultaneously delivering a first fluid from a first reagent-dispensing device and a second fluid from a second reagent-dispensing device to the reaction vessel comprises maintaining a constant stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxylate for at least 2 minutes, or for at least 10 minutes.

13. The method of claim 1 , wherein the first and second reagent-dispensing devices include syringes actuated by respective motors or a common motor.

14. 10. The method of claim 1, wherein delivering comprises pumping the first and second fluids to a mixing point upstream of the reaction vessel, and delivering the mixture of the first and second fluids from the mixing point to the reaction vessel.

15. The method of claim 1 , further comprising cooling the reaction vessel during the simultaneous delivering steps.

16. 13. A hydrogenation catalyst formed by the process of claim 1.

17. A rubber composition comprising a hydrogenated elastomer hydrogenated with the hydrogenation catalyst according to claim 16, and at least one additive selected from the group consisting of a filler, a plasticizer, zinc oxide, and a sulfur-based curing agent.

18. In combination, a first reagent-dispensing device containing a first reagent comprising an organoaluminum compound; a second reagent-dispensing device comprising a second reagent comprising a nickel alkoxylate; a first delivery tube connecting the first reagent-dispensing device and the mixing point; a second delivery tube connecting a second reagent-dispensing device and said mixing point; Reaction vessel, a common delivery pipe connecting said mixing points to a reaction vessel; a pressurizing mechanism for pressurizing the first and second reagents so that they are delivered to the reaction vessel at a constant stoichiometry of aluminum in the organoaluminum compound and nickel in the nickel alkoxylate; 1. An apparatus and reagent for forming a hydrogenation catalyst comprising:

19. 20. The apparatus of claim 18, wherein the first and second reagent-dispensing devices comprise first and second syringes.

20. 20. The device of claim 19, wherein the pressurizing mechanism includes a motor that drives a plunger of at least one of the first and second syringes.

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