Method of producing functionalized polymers, rubber composition, and pneumatic tire

Abstract

To provide a method for producing a new functionalized polymer for controlling the condensation of silane functionalized polymers, which can hydrolyze and condense significantly through finishing when exposed to water, heat, and work.SOLUTION: There is provided a process for producing a functionalized polymer comprising the steps of: producing an aminosilane functionalized polymer in a polymer cement; and reacting a condensation suppressant comprising an alkoxysilane with the aminosilane functionalized polymer to form a stable functionalized polymer in the polymer cement. By adding an alkoxysilane to in-process polymer cement after the silane is attached and polymerization is complete, it is possible to mitigate and control hydrolysis and condensation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a functionalized polymer, a rubber composition, and a method for making a pneumatic tire. [Background technology]

[0002] Silane-functionalized polymers can undergo significant hydrolysis and condensation during finishing when exposed to water, heat, and handling. Condensation of functional groups in the polymer is known to result in coupling. The degree of coupling directly correlates to an increase in polymer Mooney Viscosity. Silane functional groups bearing electron-withdrawing groups, including alkoxy and amino groups, are particularly susceptible to hydrolysis and condensation. Some silane-functionalized polymers condense to such an extent that they become unusable in their targeted applications. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 4,048,420 [Patent Document 2] U.S. Patent No. 4,935,471 [Patent Document 3] U.S. Patent No. 6,242,534 [Patent Document 4] U.S. Patent No. 6,207,757 [Patent Document 5] U.S. Patent No. 6,133,364 [Patent Document 6] U.S. Patent No. 6,372,857 [Patent Document 7] U.S. Patent No. 5,395,891 [Patent Document 8] U.S. Patent No. 6,127,488 [Patent Document 9] U.S. Patent No. 5,672,639 [Patent Document 10] U.S. Patent No. 6,608,125 [Patent Document 11] U.S. Patent Publication No. 2003 / 0130535 [Non-patent literature]

[0004] [Non-Patent Document 1] Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition, the Institute of Petroleum, United Kingdom [Non-Patent Document 2] the Journal of the American Chemical Society, Vol. 60, p. 304 (1930) [Non-Patent Document 3] The Vanderbilt Rubber Handbook (1978), pp. 344-346 Summary of the Invention [Problem to be solved by the invention]

[0005] It would be desirable to develop new methods for controlling such condensations. [Means for solving the problem]

[0006]

[0003] By adding alkoxysilanes to in-process polymer cements after the silanes are bonded and polymerization is complete, hydrolysis and condensation can be mitigated and controlled, thereby controlling polymer coupling and the final polymer Mooney viscosity. Such control can lead to a broader range of useful functional polymers across multiple industries. Non-limiting examples of suitable alkoxysilanes include triethoxy(octyl)silane and 3-octanoylthio-1-propyltriethoxysilane. The alkoxysilanes function as condensation inhibitors.

[0007] In some embodiments, a method for producing a functionalized polymer is disclosed that includes the steps of producing an aminosilane-functionalized polymer in a polymer cement and reacting a condensation inhibitor comprising an alkoxysilane with the aminosilane-functionalized polymer to form a stable functionalized polymer in the polymer cement.

[0008]

[0005] The method may further include the steps of providing a quenching agent to the polymer cement; removing volatile compounds from the polymer cement; and / or drying the polymer cement and recovering the stable functionalized polymer.

[0009]

[0006] In some embodiments, the alkoxysilane is triethoxysilane.

[0010] The alkoxysilane may be selected from triethyloxy(octyl)silane and 3-(triethoxysilyl)propylthiooctanoate.

[0011] In some embodiments, the stable functionalized polymer has a Mooney viscosity of less than 100, less than 80, or less than 60 after 21 days aging.

[0012]

[0009] The aminosilane functionalized polymer may be produced by reacting a living anionic elastomeric polymer with a polymerization terminator of formula I.

[0013] [ka] [wherein X is Cl, Br, or I; m is an integer from 0 to 2, n is an integer from 1 to 3, and n+m=3; R 1 , R 2 are independently C1-C18 alkyl, aryl, or a combination thereof, or R 1 , R 2is independently -SiR, where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 1 and R 2 together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom form a 5- to 8-membered ring; R 3 is hydrogen, or C1-C18 alkyl, aryl, or a combination thereof, or R 3 is -SiR, where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 3 -R 6 -R 7 (In the formula, R 6 is C1-C3 alkanediyl, R 7 is represented by the following structures -SZ, -N(R 8 )(R 9 ), -O(Y), or Si(OR 10 ) 3, where R 8 and R 9 is independently a C1-C18 alkyl, aryl, or a combination thereof; Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, and isopropyldimethylsilyl; R 10 are independently C1-C4 alkyl.

[0014] Or when m=1, the polymerization shortstop may have formula II:

[0015] [ka] [In the formula, R 4 , R 5 are independently C1-C18 alkyl, aryl, or a combination thereof, or R 4 , R 5are independently -SiR, where R is independently alkyl, aryl, alkoxy, or disubstituted amino; X and R 3 is as previously defined, and k is an integer from 0 to 10.

[0016] In some embodiments, the polymerization shortstop is [ka] is selected from the group consisting of:

[0017] The living anionic elastomers may be derived from at least one diene monomer and optionally at least one vinyl aromatic monomer.

[0018] In some embodiments, the living anionic elastomer is derived from at least one of isoprene and butadiene, and optionally styrene.

[0019] The living anionic elastomer may be derived from butadiene and styrene.

[0020]

[0014] A rubber composition containing the functionalized polymer produced by the above-described method is also disclosed. The composition may further contain silica. A pneumatic tire containing the rubber composition is also disclosed.

[0021]

[0015] In another embodiment, a method for producing a functionalized polymer is disclosed, the method including reacting a condensation inhibitor comprising an alkoxysilane with an aminosilane-functionalized polymer to form a stable functionalized polymer in a polymer cement.

[0022]

[0016] These and other non-limiting aspects and / or objectives of the disclosure are described in more detail below.

[0023]

[0017] Below is a brief description of the drawings, presented for the purpose of illustrating, and not for the purpose of limiting, the exemplary embodiments disclosed herein. [Brief description of the drawings]

[0024] [Figure 1] 1 is a flow chart illustrating a method for producing a functionalized polymer according to some embodiments of the present disclosure. [Diagram 2] FIG. 1 is a partial side view of a non-limiting example of a tire according to some embodiments of the present disclosure. [Diagram 3] 1 is a flowchart illustrating a non-limiting example method of forming an article according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025]

[0021] The present disclosure may be more readily understood by reference to the following detailed description of the preferred embodiments contained therein, and the drawings in which: In the following specification and in the claims that follow, reference will be made to a number of terms that shall be defined to have the following meanings.

[0026]

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Methods and materials are described below, but similar or equivalent methods and materials can be used in the practice or testing of this disclosure. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and articles disclosed herein are merely illustrative and are not intended to be limiting.

[0027]

[0023] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0028]

[0024] The term "comprising" as used in the specification and in the claims may include "consisting of" and "consisting essentially of" embodiments. As used herein, the terms "comprise(s)", "include(s)", "having", "has", "can", "contain(s)", and variations thereof, are intended to be open-ended transitional phrases that require the presence of the named components / steps and allow for the presence of other components / steps. However, such statements should also be construed as describing compositions, mixtures, or methods that "consist of" and "consist essentially of" the recited components / steps, allowing for the presence of only the named components / steps, along with any impurities that may result from the named components / steps, and excluding other components / steps.

[0029]

[0025] Unless otherwise indicated to the contrary, numerical values ​​in this specification should be understood to include numerical values ​​that are the same when given the same number of significant digits, as well as numerical values ​​that differ from the stated value by less than the experimental error of conventional measuring techniques of the type used to determine the particular value.

[0030]

[0026] All ranges disclosed herein are inclusive of the recited endpoints and are independently combinable (e.g., the range "from 2 to 10" includes the endpoints 2 and 10 and all intermediate values). The endpoints of the ranges and any values ​​disclosed herein are not limited to the exact ranges or values; they are imprecise enough to include values ​​that are approximations of these ranges and / or values.

[0031]

[0027] Approximate language as used herein may be applied to modify any quantitative expression that may vary without resulting in a change in the basic function to which the language pertains. Thus, a value modified by one or more terms such as "about" and "substantially" may not be limited to the exact value specified in some cases. The modifier "about" should also be considered to disclose a range defined by the absolute values ​​of the two endpoints. For example, the phrase "about 2 to about 4" also discloses a range of "2 to 4". The term "about" may refer to plus or minus 10% of the indicated numerical value. For example, "about 10%" may indicate a range of 9% to 11%, and "about 1" may mean 0.9 to 1.1.

[0032]

[0028] In the recitation of numerical ranges herein, each intervening numerical value is expressly contemplated to the same degree of precision, for example, in the range 6 to 9, the numerical values ​​7 and 8 are contemplated in addition to 6 and 9, and in the range 6.0 to 7.0, the numerical values ​​6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are expressly contemplated.

[0033]

[0029] The present disclosure relates to a method for producing a functionalized polymer. A rubber composition containing the functionalized polymer, and a pneumatic tire containing the rubber composition are also disclosed.

[0034] FIG. 1 is a flow chart illustrating a method 100 for producing a functionalized polymer according to some embodiments of the present disclosure.

[0035]

[0031] The method 100 includes a step 110 of producing an aminosilane-functionalized polymer, a step 120 of reacting a condensation inhibitor comprising an alkoxysilane (e.g., ethoxysilane) with the aminosilane-functionalized polymer, a step 130 of quenching, and a step 140 of finishing.

[0036]

[0032] The reaction 120 of an alkoxysilane-containing condensation inhibitor with the aminosilane-functionalized polymer can mitigate and control hydrolysis and condensation.

[0037] One of ordinary skill in the art with the knowledge of this disclosure will be able to determine when to add the alkoxysilane and determine the appropriate time, temperature, etc. for the reaction.

[0038]

[0034] The alkoxysilane may include one or more of monoethoxysilane, diethoxysilane, triethoxysilane, and / or tetraethoxysilane. In some preferred embodiments, the alkoxysilane is an ethoxysilane, which may include one or more of monoethoxysilane, diethoxysilane, triethoxysilane, and / or tetraethoxysilane.

[0039] The alkoxysilane may be selected from triethyloxy(octyl)silane and / or 3-(triethoxysilyl)propylthiooctanoate.

[0040]

[0036] The condensation inhibitor composition containing the alkoxysilane may be introduced simultaneously with an acidic proton source (e.g., stearic acid). The acid source promotes hydrolysis and condensation between the functionally terminated polymer and the condensation inhibitor. The acid source may be provided in the same composition as the alkoxysilane or in a separate stream.

[0041] A quenching step 130 may be performed to "kill" any remaining living polymer chains (e.g., living polydiene chains). This can be accomplished, for example, by adding an acidic proton source and a protic quenching agent. An antioxidant may also be added. Non-limiting examples of protic quenching agents include water and alcohols (e.g., methanol or ethanol). One of skill in the art with knowledge of this disclosure will be able to select the quenching materials and their relative amounts.

[0042]

[0038] The finishing step 140 may include removing volatiles and / or drying the finished polymer. One of ordinary skill in the art with the knowledge of this disclosure will be able to select the finishing parameters.

[0043]

[0039] Although the present application discloses examples including aminochlorosilanes, it should be understood that any end-terminated aminosilane-bearing functional group is within the scope of the present disclosure. Aminosilane-functionalized polymers may be produced as the reaction product of a living anionic elastomeric polymer with a polymerization terminator of formula I110.

[0044] [ka] [wherein X is Cl, Br, or I; m is an integer from 0 to 2, n is an integer from 1 to 3, and n+m=3; R 1 , R 2 are independently C1-C18 alkyl, aryl, or a combination thereof, or R 1 , R 2 is independently -SiR, where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 1 and R 2 together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom, form a 5- to 8-membered ring: R 3 is hydrogen, or C1-C18 alkyl, aryl, or a combination thereof, or R 3 is -SiR, where R is independently alkyl, aryl, alkoxy, or disubstituted amino, or R 3 -R 6 -R 7 (In the formula, R 6 is C1-C3 alkanediyl and R 7 The structures are as follows: -SZ, -N(R 8 )(R 9 ), -O(Y), or Si(OR 10 ) 3 are selected from R8 and R 9 is independently a C1-C18 alkyl, aryl, or a combination thereof; Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, and isopropyldimethylsilyl; R 10 are independently C1-C4 alkyl.

[0045] Or when m=1, the polymerization shortstop may have formula II: [ka] [In the formula, R 4 , R 5 are independently C1-C18 alkyl, aryl, or a combination thereof, or R 4 , R 5 are independently -SiR, where R is independently alkyl, aryl, alkoxy, or disubstituted amino; X and R 3 is as defined above, and k is an integer from 0 to 10.

[0046] Further disclosed is a rubber composition comprising the functionalized elastomer, and a pneumatic tire comprising the polymer.

[0047]

[0041] The initiators used to initiate the polymerization used in the synthesis of rubbery living polymers may be selected from the group consisting of barium, lithium, magnesium, sodium, and potassium. Lithium and magnesium are the most commonly utilized metals in the synthesis of such metal terminated polymers (living polymers). Lithium initiators are usually more preferred.

[0048] Organolithium compounds are preferred initiators for use in such polymerizations. The organolithium compounds utilized as initiators are usually organomonolithium compounds. The organolithium compounds preferred as initiators are monofunctional compounds that can be represented by the formula R-Li, where R represents a hydrocarbyl radical containing from 1 to about 20 carbon atoms. Generally, such monofunctional organolithium compounds will contain from 1 to about 10 carbon atoms. Some preferred representative examples are butyllithium, secbutyllithium, n-hexyllithium, n-octyllithium, tertoctyllithium, n-decyllithium, phenyllithium, 1-naphthyllithium, 4-butylphenyllithium, p-tolyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-butylcyclohexyllithium, and 4-cyclohexylbutyllithium. Secondary butyllithium is a highly preferred organolithium initiator. Very finely divided lithium having an average particle size of less than 2 microns can also be used as initiators for the synthesis of rubbery living polymers that can be functionalized with the terminator of formula I. U.S. Patent No. 4,048,420, the teachings of which are incorporated herein by reference in their entirety, describes the synthesis of lithium-terminated living polymers utilizing finely divided lithium as an initiator. Lithium amides can also be used as initiators in the synthesis of living polydiene rubbers (see U.S. Patent No. 4,935,471, the teachings of which are incorporated herein by reference for lithium amides which can be used as initiators in the synthesis of rubbery living polymers).

[0049] The amount of organolithium initiator utilized will vary depending on the molecular weight desired for the rubbery polymer being synthesized as well as the exact polymerization temperature to be used. The exact amount of organolithium compound required to produce a polymer of the desired molecular weight can be readily ascertained by one skilled in the art. However, as a general rule, 0.01 to 1 phm (parts per hundred parts by weight of monomer) of organolithium initiator will be utilized. In most cases, 0.01 to 0.1 phm of organolithium initiator will be utilized, with 0.025 to 0.07 phm being preferred.

[0050] Many types of unsaturated monomers containing carbon-carbon double bonds can be polymerized into polymers using such metal catalysts. Elastomers or rubbery polymers can be synthesized by polymerizing diene monomers utilizing this type of metal initiator system. The diene monomers that can be polymerized into synthetic rubbery polymers can be either conjugated or non-conjugated diolefins. Conjugated diolefin monomers containing 4 to 8 carbon atoms are generally preferred. Vinyl-substituted aromatic monomers can also be copolymerized with one or more diene monomers into rubbery polymers, such as styrene-butadiene rubber (SBR). Some representative examples of conjugated diene monomers that can be polymerized into rubbery polymers include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, 2-phenyl-1,3-butadiene, and 4,5-diethyl-1,3-octadiene. Some representative examples of vinyl substituted aromatic monomers which can be utilized in the synthesis of rubbery polymers include styrene, 1-vinylnaphthalene, 3-methylstyrene, 3,5-diethylstyrene, 4-propylstyrene, 2,4,6-trimethylstyrene, 4-dodecylstyrene, 3-methyl-5-normal-hexylstyrene, 4-phenylstyrene, 2-ethyl-4-benzylstyrene, 3,5-diphenylstyrene, 2,3,4,5-tetraethylstyrene, 3-ethyl-1-vinylnaphthalene, 6-isopropyl-1-vinylnaphthalene, 6-cyclohexyl-1-vinylnaphthalene, 7-dodecyl-2-vinylnaphthalene, α-methylstyrene, and the like.

[0051] The metal terminated rubbery polymers functionalized with the terminator of formula I may be prepared by solution polymerization utilizing an inert organic solvent such as a saturated aliphatic hydrocarbon, an aromatic hydrocarbon, or an ether. The solvents used in such solution polymerizations usually contain from about 4 to about 10 carbon atoms per molecule and become liquid under the conditions of the polymerization. Some representative examples of suitable organic solvents include pentane, isooctane, cyclohexane, normal-hexane, benzene, toluene, xylene, ethylbenzene, tetrahydrofuran, and the like, either alone or in mixtures. For example, the solvent can be a mixture of various hexane isomers. Such solution polymerizations result in the formation of a polymer cement (a highly viscous solution of the polymer). The polymerization may include modifiers such as methyl tetrahydrofurfuryl ether, ethyl tetrahydrofurfuryl ether, propyl tetrahydrofurfuryl ether, butyl tetrahydrofurfuryl ether, hexyl tetrahydrofurfuryl ether, octyl tetrahydrofurfuryl ether, dodecyl tetrahydrofurfuryl ether, diethyl ether, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, trimethylamine, triethylamine, N,N,N',N'-tetramethylethylenediamine (TMEDA), N-methylmorpholine, N-ethylmorpholine, N-phenylmorpholine, or oligomeric oxolanyl alkanes such as 2,2-di-tetrahydrofurylpropane (DTP).

[0052] The metal terminated rubbery living polymers can be of virtually any molecular weight. However, the number average molecular weight of the rubbery living polymers will typically be within the range of about 50,000 to about 500,000. It is more typical for such rubbery living polymers to have number average molecular weights within the range of 100,000 to 250,000.

[0053] Metal terminated rubbery living polymers can be functionalized by simply adding a stoichiometric amount of a terminating agent of formula I or II to a solution of the rubbery polymer (rubber cement of living polymer). In other words, about one mole of a terminating agent of formula I or II is added per mole of terminal metal groups in the rubbery living polymer. The number of moles of metal end groups in such a polymer is assumed to be the number of moles of metal utilized in the initiator. Of course, it is possible to add more than a stoichiometric amount of a terminating agent of formula I or II. However, utilizing a larger amount is not beneficial to the final polymer properties. Nevertheless, in many cases it will be desirable to utilize a slight excess of a terminating agent of formula I or II to ensure that at least a stoichiometric amount is actually utilized or to control the stoichiometry of the functionalization reaction. In one embodiment, 0.05 to 5 moles of a terminating agent of formula I or II will be utilized per mole of metal end groups in the living polymer being treated (molar equivalents). In one embodiment, about 0.8 to about 1.1 moles of terminating agent of formula I or II will be utilized per mole of metal end groups in the living polymer being treated. Of course, lesser amounts of terminating agent of formula I or II can be utilized if it is not desired to functionalize all of the metal terminated chain ends in the rubbery polymer.

[0054] The terminators of formula I or II will react with metal terminated rubbery living polymers over a very wide temperature range. For practical reasons, the functionalization of such rubbery living polymers will usually be carried out at temperatures in the range of 0°C to 150°C. To increase the reaction rate, it is preferred in most cases to utilize temperatures in the range of 20°C to 100°C, with temperatures in the range of 50°C to 80°C being most preferred. The capping reaction is very fast and only very short reaction times in the range of 0.05 to 4 hours are usually required. However, in some cases reaction times of up to about 24 hours may be used to ensure maximum conversion.

[0055] In various embodiments, suitable terminators include structures 1-4 below: [ka]

[0056] The polymer may be compounded into a rubber composition.

[0057] In addition to the polymer, the rubber composition may optionally contain one or more rubbers or elastomers containing olefinic unsaturation. The phrase "rubber or elastomer containing olefinic unsaturation" or "diene-based elastomer" is intended to include both natural rubber and its various raw and reclaim forms, as well as various synthetic rubbers. In this description, the terms "rubber" and "elastomer" may be used interchangeably unless otherwise specified. The terms "rubber composition," "compounded rubber," and "rubber compound" are used interchangeably to refer to rubber blended or mixed with various ingredients and materials, such terms being well known to those skilled in the art of rubber mixing or compounding. Representative synthetic polymers are the homopolymerization products of butadiene and its analogs and derivatives, such as methylbutadiene, dimethylbutadiene, and pentadiene, as well as copolymers such as those formed from butadiene or its analogs or derivatives with other unsaturated monomers. Among the latter are acetylenes, such as vinyl acetylene; olefins, such as isobutylene, which is copolymerized with isoprene to form butyl rubber; vinyl compounds, such as acrylic acid, acrylonitrile (which is copolymerized with butadiene to form NBR), methacrylic acid, and styrene, which is polymerized with butadiene to form SBR, as well as vinyl esters, and various unsaturated aldehydes, ketones, and ethers, such as acrolein, methyl isopropenyl ketone, and vinyl ethyl ether. Specific examples of synthetic rubbers include neoprene (polychloroprene), polybutadiene (including cis-1,4-polybutadiene), polyisoprene (including cis-1,4-polyisoprene), butyl rubber, halobutyl rubber such as chlorobutyl rubber or bromobutyl rubber, styrene / isoprene / butadiene rubber, copolymers of 1,3-butadiene or isoprene with monomers such as styrene, acrylonitrile, and methacrylates, and ethylene / propylene terpolymers, also known as ethylene / propylene / diene monomer (EDPM), especially ethylene / propylene / dicyclopentadiene terpolymer.Additional examples of rubbers that may be used include alkoxy-silyl end-functionalized solution polymerized polymers (SBR, PBR, IBR, and SIBR), silicon-coupled and tin-coupled star-branched polymers. Preferred rubbers or elastomers are polyisoprene (natural or synthetic), polybutadiene, and SBR.

[0058] In some embodiments, the at least one additional rubber is preferably of at least two diene-based rubbers, such as cis 1,4-polyisoprene rubber (natural or synthetic, but preferably natural), 3,4-polyisoprene rubber, styrene / isoprene / butadiene rubber, emulsion and solution polymerization derived styrene / butadiene rubber, cis 1,4-polybutadiene rubber, and butadiene / acrylonitrile copolymers prepared by emulsion polymerization, or combinations of two or more rubbers.

[0059] In some embodiments, emulsion polymerization derived styrene / butadiene (E-SBR) may be used having a more conventional styrene content of about 20 to about 28 percent bound styrene, or, in some applications, E-SBR having a medium to relatively high bound styrene content, i.e., about 30 to about 45 percent bound styrene.

[0060] By emulsion polymerization prepared E-SBR, it is meant that styrene and 1,3-butadiene are copolymerized as an aqueous emulsion. Such are well known to those skilled in such art. The amount of bound styrene may vary, for example, from about 5 to about 50 percent. In one embodiment, the E-SBR may contain acrylonitrile to form a terpolymer rubber as an E-SBAR, for example, in an amount of about 2 to about 30 weight percent bound acrylonitrile in the terpolymer.

[0061] Emulsion polymerization prepared styrene / butadiene / acrylonitrile copolymer rubbers containing from about 2 to about 40 weight percent bound acrylonitrile in the copolymer are also contemplated as diene based rubbers.

[0062] Solution polymerization prepared SBR (S-SBR) typically has a bound styrene content ranging from about 5 to about 50, preferably from about 9 to about 36 percent. S-SBR can be conveniently prepared, for example, by organolithium catalysis in the presence of an organic hydrocarbon solvent.

[0063] In one embodiment, cis 1,4-polybutadiene rubber (BR) may be used. Such BR may be prepared, for example, by organic solution polymerization of 1,3-butadiene. The BR may be conveniently characterized, for example, by having a cis 1,4-content of at least 90 percent.

[0064]

[0058] cis 1,4-polyisoprene and cis 1,4-polyisoprene natural rubber are well known to those having skill in the rubber art.

[0065]

[0059] The term "phr" as used herein, in accordance with conventional practice, refers to "parts by weight of a respective material per 100 parts by weight of rubber or elastomer."

[0066] The rubber composition may contain up to 70 phr of processing oil. The processing oil may be included in the rubber composition as an extending oil typically used to extend the elastomer. The processing oil may be included in the rubber composition by adding the oil directly during rubber compounding. The processing oil used may include both the extending oil present in the elastomer and the processing oil added during compounding. Suitable processing oils include various oils known in the art, including aromatic, paraffinic, naphthenic, vegetable oils, and low PCA oils, such as MES, TDAE, SRAE, and heavy naphthenic oils. Suitable low PCA oils include those having a polycyclic aromatic content of less than 3 weight percent as determined by the IP346 method. The procedure for the IP346 method can be found in Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd Edition, published by the Institute of Petroleum, United Kingdom.

[0067] The rubber composition may contain from about 10 to about 150 phr of silica. In another embodiment, from 20 to 80 phr of silica may be used.

[0068]

[0062] Commonly used siliceous pigments that may be used in rubber compounds include conventional pyrogenic and precipitated siliceous pigments (silica). In one embodiment, precipitated silicas are used. The conventional siliceous pigments used are precipitated silicas, such as those obtained by the acidification of soluble silicates, e.g. sodium silicate.

[0069] Such conventional silicas may be characterized, for example, by having a BET (Brunauer-Emmett-Teller) surface area, as measured using nitrogen gas. In one embodiment, the BET surface area may range from about 40 to about 600 square meters per gram. In another embodiment, the BET surface area may range from about 80 to about 300 square meters per gram. The BET method of measuring surface area is described in the Journal of the American Chemical Society, Vol. 60, p. 304 (1930).

[0070] Conventional silicas may be characterized as having a dibutyl phthalate (DBP) absorption value ranging from about 100 to about 400, alternatively from about 150 to about 300.

[0071]

[0065] Conventional silicas can be expected to have an average ultimate particle size in the range of 0.01 to 0.05 microns as determined, for example, by electron microscopy, although the silica particles may be smaller or possibly larger in size.

[0072]

[0066] Various commercially available silicas may be used, such as, by way of example only and without limitation herein, silicas commercially available from PPG Industries under the Hi-Sil trademark designated 210, 243, etc.; silicas available from Rhodia designated, for example, Z1165MP and Z165GR, and silicas available from Degussa AG designated, for example, VN2 and VN3.

[0073]

[0067] Commonly used carbon blacks can be used as conventional fillers in amounts ranging from 10 to 150 phr. In another embodiment, 20 to 80 phr of carbon black may be used. Representative examples of such carbon blacks include N110, N121, N134, N220, N231, N234, N242, N293, N299, N315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990, and N991. These carbon blacks have iodine absorptions ranging from 9 to 145 g / kg and iodine concentrations ranging from 34 to 150 cm 3 It has a DBP value of up to / 100g.

[0074] Other fillers may be used in the rubber composition, including, but not limited to, particulate fillers including ultra-high molecular weight polyethylene (UHMWPE), crosslinked particulate polymer gels including, but not limited to, those disclosed in U.S. Patent Nos. 6,242,534; 6,207,757; 6,133,364; 6,372,857; 5,395,891; or 6,127,488, and plasticized starch composite fillers including, but not limited to, those disclosed in U.S. Patent No. 5,672,639. The aforementioned patents are incorporated herein by reference in their entirety. Such other fillers may be used in amounts ranging from 1 to 30 phr.

[0075] In some embodiments, the rubber composition may contain a conventional sulfur-containing organosilicon compound. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(trimethoxy or triethoxysilylpropyl) polysulfide. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(triethoxysilylpropyl) disulfide and / or 3,3'-bis(triethoxysilylpropyl) tetrasulfide.

[0076]

[0070] In some embodiments, suitable sulfur-containing organosilicon compounds include those disclosed in U.S. Patent No. 6,608,125. In one embodiment, the sulfur-containing organosilicon compound includes 3-(octanoylthio)-1-propyltriethoxysilane, CH3(CH2)6C(=O)-S-CH2CH2CH2Si(OCH2CH3)3 (commercially available as NXT™ from Momentive Performance Materials).

[0077]

[0071] In another embodiment, suitable sulfur-containing organosilicon compounds include those disclosed in U.S. Patent Publication No. 2003 / 0130535, the entirety of which is incorporated herein by reference. In one embodiment, the sulfur-containing organosilicon compound is Si-363 manufactured by Degussa.

[0078] The amount of the sulfur-containing organosilicon compound in the rubber composition will vary depending on the level of other additives used. Generally, the amount of the compound will range from 0.5 to 20 phr. In one embodiment, the amount will range from 1 to 10 phr.

[0079]

[0073] It will be readily understood by those skilled in the art that the rubber composition may be compounded by methods generally known in the art of rubber compounding, such as mixing various sulfur-vulcanizable component rubbers with various commonly used additive materials, such as sulfur donors, curing aids, such as activators and retarders, processing additives, such as oils, resins including tackifying resins, and plasticizers, fillers, pigments, fatty acids, zinc oxide, waxes, antioxidants, and antiozonants, and peptizers. Depending on the sulfur vulcanizability and the intended use of the sulfur-vulcanized material (rubber), as known to those skilled in the art, the above-mentioned additives are selected and generally used in conventional amounts. Representative examples of sulfur donors include elemental sulfur (free sulfur), amine disulfides, polymeric polysulfides, and sulfur olefin adducts. In one embodiment, the sulfur-vulcanizing agent is elemental sulfur. The sulfur-vulcanizing agent may be used in an amount ranging from 0.5 to 8 phr, or in a range of 1.5 to 6 phr. A typical amount of tackifying resin, if used, comprises about 0.5 to about 10 phr, usually about 1 to about 5 phr. A typical amount of processing aid comprises about 1 to about 50 phr. A typical amount of antioxidant comprises about 1 to about 5 phr. Representative antioxidants may be, for example, diphenyl-p-phenylenediamine and others, such as those disclosed in The Vanderbilt Rubber Handbook (1978), pages 344 to 346. A typical amount of antiozonant comprises about 1 to 5 phr. A typical amount of fatty acid, which may include stearic acid, if used, comprises about 0.5 to about 3 phr. A typical amount of zinc oxide comprises about 2 to about 5 phr. A typical amount of wax comprises about 1 to about 5 phr. Often, microcrystalline wax is used. A typical amount of peptizer comprises about 0.1 to about 1 phr. Typical peptizers may be, for example, pentachlorothiophenol and dibenzamidodiphenyl disulfide.

[0080] Accelerators are used to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanizate. In one embodiment, a single accelerator system may be used, i.e., a primary accelerator. The primary accelerator(s) may be used in a total amount ranging from about 0.5 to about 4, or alternatively from about 0.8 to about 1.5 phr. In another embodiment, a combination of primary and secondary accelerators may be used, with the secondary accelerator being used in a smaller amount, for example from about 0.05 to about 3 phr, to activate the vulcanizate and improve its properties. These accelerator combinations may be expected to produce a synergistic effect on the final properties, somewhat better than those produced by the use of either accelerator alone. Additionally, delayed-acting accelerators may be used that produce a satisfactory cure at normal vulcanization temperatures without being affected by normal processing temperatures. Vulcanization retarders may also be used. Suitable accelerator types that may be used include amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates, and xanthates. In one embodiment, if a second accelerator is used, the primary accelerator is a sulfenamide and the secondary accelerator may be a guanidine, dithiocarbamate, or thiuram compound.

[0081]

[0075] The mixing of the rubber composition can be accomplished by methods known to those skilled in the rubber mixing art. For example, the components are typically mixed in at least two stages, namely at least one non-productive stage followed by a productive mix stage. The final curatives, including sulfur-vulcanizing agents, are typically mixed in the final stage, conventionally referred to as the "productive" mix stage, in which mixing typically occurs at a temperature lower than the mixing temperature(s) in the preceding non-productive mix stage(s) or at the final temperature. The terms "non-productive" and "productive" mix stages are well known to those skilled in the rubber mixing art. The rubber composition may be subjected to a thermomechanical mixing step. The thermomechanical mixing step generally involves mechanical work in a mixer or extruder for a suitable period of time to bring the rubber temperature between 140°C and 190°C. The suitable duration of the thermomechanical work varies as a function of the operating conditions and the volume and nature of the components. For example, the thermomechanical work may be from 1 to 20 minutes.

[0082]

[0076] The rubber composition may be incorporated into various rubber components of a tire. For example, the rubber component may be the tread (including the tread cap and tread base), sidewall, apex, chafer, sidewall insert, wire coat, or innerliner. In one embodiment, the component is the tread.

[0083]

[0077] The pneumatic tire may be a race tire, passenger tire, aircraft tire, agricultural, civil engineering, off-the-road, truck tire, and the like. In one embodiment, the tire is a passenger or truck tire. The tire may be radial or bias.

[0084]

[0078] The rubber compositions may be used in other products including, but not limited to, non-pneumatic tires, belts, hoses, shoes, air springs, engine mounts, and the like.

[0085]

[0079] Vulcanization of pneumatic tires may be carried out at conventional temperatures ranging from about 100°C to 200°C. In one embodiment, vulcanization is carried out at temperatures ranging from about 110°C to 180°C. Any conventional vulcanization process may be used, such as heating in a press or mold, heating with superheated steam or hot air, etc. Such tires may be built, shaped, molded, and cured by a variety of methods that are known and readily apparent to those skilled in such art.

[0086]

[0080] Figure 2 is a partial side view of a non-limiting example of a tire 201 according to some embodiments of the present disclosure. The tire 201 includes a tread portion 202, a bead portion 203, and a sidewall portion 204 positioned between the tread portion 202 and the bead portion 203. The tread portion 202, the bead portion 203, and the sidewall portion 204 of a tire according to the present disclosure are not limited to the specific configuration shown in Figure 2. For example, there may be multiple sidewall portions, ribs, patterns, colors, etc. Figure 2 is provided to show one example of where the composition of the present disclosure may be utilized. A functionalized polymer may be utilized in one or more of the tread portion 202, the bead portion 203, and the sidewall portion 204.

[0087] 3 is a flow chart illustrating a non-limiting example of a method 345 for forming an article (e.g., a tire) according to some embodiments of the present disclosure. The method 345 includes a step 350 of providing a composition, a non-productive mix step 360, a productive mix step 370, and a vulcanization step 380.

[0088] The following examples are provided to illustrate the devices and methods of the present disclosure. The examples are merely illustrative and are not intended to limit the disclosure to the materials, conditions, or process parameters previously described herein. EXAMPLES

[0089] In the following examples, to reduce the polymer-to-polymer batch variations that naturally result from the ongoing polymerization reaction, a 27 gallon batch reactor was used to produce aminosilane-functionalized polymer as described in Example 1. This single batch was then split into several smaller reactors for post-functionalization processing experiments.

[0084] EXAMPLES

[0090] This example describes the production of a single batch, aminosilane functionalized polymer, which was subsequently split among Examples 2-5. To a 27 gallon reactor was added a solution of 1,3-butadiene and vinyl content modifier in n-hexane at a reactor temperature of 65° C. To this solution was charged a solution of n-butyllithium (0.05 phm). After the monomer conversion reached 98-99% as determined by GC-MS, a solution of bis(dimethylamino)methylchlorosilane (1.0 equivalent relative to n-BuLi) (aminosilane) functional terminator was added. The functionalization reaction was allowed to proceed to the end of the residence time. The resulting polymer cement was split for use in subsequent examples.

[0086] EXAMPLES

[0091] In this example, a comparative example was made to illustrate the unmitigated Mooney Jump in aminosilane-functionalized polymers without post-functionalization treatment to mitigate hydrolysis and condensation reactions of the functional end groups. The aminosilane-functionalized polymer cement produced according to Example 1 was quenched using a protic shortstop and antioxidants were added. The resulting cement was worked up using procedures familiar to those skilled in the art for stripping the cement of volatiles and drying the finished polymer. Aging studies were performed on the resulting polymer to track the Mooney Change over time.

[0088] EXAMPLES

[0092] In this example, a comparative example was made to illustrate the Mooney jump in aminosilane-functionalized polymers when the polymers were subjected to classical post-functionalization treatments to drive the hydrolysis and condensation reactions of the aminosilane end groups. To the aminosilane-functionalized polymer cement produced according to Example 1, a solution of an acidic proton source and a protic quenching agent was added to drive the hydrolysis and condensation reactions towards completion, followed by the addition of an antioxidant. The resulting cement was worked up using procedures familiar to those skilled in the art for stripping the cement of volatiles and drying the finished polymer. Aging studies were performed on the resulting polymers to follow the Mooney changes over time.

[0090] EXAMPLES

[0093] This example describes the use of triethyloxy(octyl)silane as a condensation inhibitor for post-functionalization treatment. A solution of triethyloxy(octyl)silane was added to the aminosilane-functionalized polymer cement produced according to Example 1. This mixture allowed for a short residence time (e.g., 10 to 40 minutes) before adding the protic quenching agent and antioxidant (which may be added as a quenching agent in the same step or in separate steps). The resulting cement was worked up using procedures familiar to those skilled in the art for stripping the cement of volatiles and drying the finished polymer. Aging studies were performed on the resulting polymer to follow the Mooney changes over time.

[0092] EXAMPLES

[0094] This example describes the use of 3-(triethoxysilyl)propylthiooctanoate as a hydrolysis / condensation moderator for post-functionalization treatment. A solution of 3-(triethoxysilyl)propylthiooctanoate was added to an aminosilane-functionalized polymer cement produced according to Example 1. The mixture was allowed a short residence time before adding the protic quenching agent and antioxidant. The resulting cement was worked up using procedures familiar to those skilled in the art for stripping the cement of volatiles and drying the finished polymer. Aging studies were performed on the resulting polymer to follow the Mooney changes over time.

[0095]

[0094] Results

[0095] Table 1 summarizes the results of Examples 2 to 5.

[0096] [Table 1]

[0097] A clear difference is observed between Comparative Example 2 and Comparative Example 3, as shown by the Mooney changes throughout the process of these examples and the resulting polymers. Example 2 demonstrates that, despite the apparently acceptable Mooney after finishing, the hydrolysis and condensation reactions of the aminosilane functional end groups are incomplete, as evidenced by the extreme Mooney increase with aging as these reactions proceed to completion in the bulk polymer. Example 3 shows that classical hydrolysis and condensation promoters give either partially or nearly completely bonded polymer products with the polymer chains condensing together. The Mooney after aging of these products is near the upper limit that the Mooney viscometer can accurately detect. Another issue is that these materials behave as their measured viscosity, meaning that they are not destroyed in the mixer during compounding to behave or function as lower Mooney polymers.

[0098] Conversely, Examples 4 and 5 demonstrate the use of a hydrolysis mitigating agent. Some hydrolysis and condensation still occurs, as evidenced by the small increase in polymer Mooney upon finishing. However, due to the reaction between the aminosilane end groups of the polymer and the selected ethoxysilane-containing mitigating agent [triethyloxy(octyl)silane in Example 4, and 3-(triethoxysilyl)propylthiooctanoate in Example 5], the functionalized polymer cannot condense as much with other polymer functional end groups, thereby preventing coupling. This directly prevents the increase in polymer Mooney after finishing and aging, as observed in Table 1.

[0099] Thus, those functionalized polymers treated with hydrolysis / condensation modifiers retain lower viscosity for improved aging and improved compound performance.

[0100]

[0099] This written description uses examples to describe the present disclosure, including the best mode, and to enable those skilled in the art to make and use the present disclosure. Other examples that occur to those skilled in the art are intended to be within the scope of the present disclosure if they have structural elements that do not differ from the same concept or equivalent structural elements with insubstantial differences. It will be understood that the above-disclosed and other features and functions, or alternatives thereof, may be combined with many other different systems or applications. Various, currently unforeseen or unanticipated alternatives, modifications, variations, or improvements thereon may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.

Claims

1. 1. A method for producing a functionalized polymer, comprising: forming an aminosilane-functionalized polymer in a polymer cement; reacting a condensation inhibitor comprising an alkoxysilane with the aminosilane-functionalized polymer to form a stable functionalized polymer in the polymer cement; A method comprising:

2. The method of claim 1 further comprising providing a quenching agent to the polymer cement.

3. The method of claim 2 further comprising the step of removing volatile compounds from the polymer cement.

4. The method of claim 2 further comprising drying the polymer cement and recovering the stable functionalized polymer.

5. The method of claim 1 , wherein the alkoxysilane comprises triethoxysilane.

6. The method of claim 1 , wherein the alkoxysilane comprises triethyloxy(octyl)silane.

7. The method of claim 1 , wherein the alkoxysilane comprises 3-(triethoxysilyl)propylthiooctanoate.

8. 10. The method of claim 1, wherein the stable functionalized polymer has a Mooney viscosity after 21 days aging, as measured by ISO 188:2023, of less than 100.

9. 10. The method of claim 1, wherein the stable functionalized polymer has a Mooney viscosity after 21 days aging of less than 80.

10. 10. The method of claim 1, wherein the stable functionalized polymer has a Mooney viscosity after 21 days aging of less than 60.

11. The aminosilane-functionalized polymer is produced by reacting a living anionic elastomeric polymer with a polymerization terminator of formula I, 【Chemistry 1】 [wherein X is Cl, Br, or I; m is an integer from 0 to 2, n is an integer from 1 to 3, and n+m=3; R １ , R ２ are independently C1 to C18 alkyl, aryl, or combinations thereof, or R １ , R ２ are independently -SiR ３ where R is independently alkyl, aryl, alkoxy, or disubstituted amino; or R １ and R ２ together with their common nitrogen atom and optionally a sulfur or oxygen heteroatom form a 5- to 8-membered ring; R ３ is hydrogen, or C1-C18 alkyl, aryl, or a combination thereof, or R ３ Ha-SiR ３ where R is independently alkyl, aryl, alkoxy, or disubstituted amino; or R ３ Ha-R ６ -R ７ (In the formula, R ６ is a C1-C3 alkanediyl, and R ７ is represented by the following structure -S-Z, -N(R ８ ) (R ９ ), —O(Y), or Si(OR １０ ) ３ is selected from R ８ and R ９ is independently a C1-C18 alkyl, aryl, or combination thereof; Y and Z are independently selected from the group consisting of methoxymethyl, tetrahydropyranyl, tetrahydrothiopyranyl, tetrahydrofuranyl, tert-butyl, allyl, 1-ethoxyethyl, benzyl, triphenylmethyl, triethylsilyl, triisopropylsilyl, trimethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, and isopropyldimethylsilyl; R １０ are independently C1-C4 alkyl. or when m=1, the polymerization terminator is represented by formula II 【Chemistry 2】 [In the formula, R ４ , R ５ are independently C1 to C18 alkyl, aryl, or combinations thereof, or R ４ , R ５ are independently -SiR ３ where R is independently alkyl, aryl, alkoxy, or disubstituted amino; and X and R ３ is as previously defined, and k is an integer from 0 to 10. and The method of claim 1.

12. The polymerization terminator is 【Chemistry 3】 The method of claim 11 , selected from the group consisting of:

13. 12. The method of claim 11, wherein said living anionic elastomer is derived from at least one diene monomer and optionally at least one vinyl aromatic monomer.

14. 12. The method of claim 11, wherein the living anionic elastomer is derived from at least one of isoprene and butadiene, and optionally styrene.

15. The method of claim 11 , wherein the living anionic elastomer is derived from butadiene and styrene.

16. A rubber composition comprising the functionalized polymer produced by the method of claim 1.

17. The rubber composition of claim 16 further comprising silica.

18. A pneumatic tire comprising the rubber composition of claim 16.

19. 1. A method for producing a functionalized polymer, comprising: Reacting an alkoxysilane-containing condensation inhibitor with the aminosilane-functionalized polymer to form a stable functionalized polymer in the polymer cement. A method comprising:

20. 20. The method of claim 19, wherein the alkoxysilane is selected from the group consisting of triethyloxy(octyl)silane and 3-(triethoxysilyl)propylthiooctanoate.

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