Branched modified diene rubber

Abstract

A composition comprising a curable polybutadiene polymer comprising at least 60% by weight, preferably at least 80% by weight, of units derived from butadiene based on the total weight of the polymer, the polymer having a Mooney viscosity ML1+4 at 100° C. of 42-150 MU and being branched and satisfying the following equation: Mooney viscosity ML1+4 of the polymer at 100° C. / degree of branching of the polymer Δδ≧4.6. A process for producing the polymer is also provided, as well as articles obtained with the composition and a process for producing the articles.

Description

[Technical field]

[0001] Polybutadiene polymers are the raw material for many industrial products, especially tires. They can be produced on a large scale using polymerization catalysts and catalyst systems described, for example, in US Pat. No. 5,399,623 and US Pat. No. 5,499,636. These processes usually lead to highly linear polymers. Highly linear polybutadienes are known to improve rolling resistance and rebound. However, highly linear polybutadienes tend to have high solution viscosity and cold flow and are difficult to process. The processing of polybutadienes can be improved by introducing branching into the polymer structure. Various methods of introducing branching are known. The cold flow and processing properties of polybutadienes can be improved by modifying them with sulfur-based modifiers, for example, as described in US Pat. No. 5,499,623 and references therein. This modification increases the Mooney viscosity through sulfur incorporation and forms polymer branches. According to US Pat. No. 5,499,623, the branching reaction with sulfur-based modifiers can be controlled by adding phosphate esters. According to US Pat. No. 5,599,526, the branching of butadiene polymers formed by sulfur-based modifiers can be reversed by subjecting the polymer to a mastication reaction. According to US Pat. No. 5,599,526, the properties of rubber compositions can be improved by using butadiene polymers in blends with other functionalized polymers in rubber compositions. [Prior art documents] [Patent documents]

[0002] [Patent Document 1] US Patent Application Publication No. 2020 / 0123288 [Patent Document 2] US Patent Application Publication No. 2002 / 0107339A1 [Patent Document 3] U.S. Pat. No. 5,567,784 [Patent Document 4] US Patent Application Publication No. 2022 / 0010105A1 [Patent Document 5] International Publication No. 2015 / 05055511A1 Brochure [Patent Document 6] US Patent Application Publication No. 2016 / 0237259A1 Summary of the Invention [Problem to be solved by the invention]

[0003] Surprisingly, it has been found that the properties of polybutadiene treated with sulfur-based modifiers can be further improved, particularly for tire applications, by adjusting the degree of branching with respect to the Mooney viscosity of the polymer, for example, by using a more branched polybutadiene instead of a highly linear polybutadiene for treatment with a sulfur-based modifier. [Means for solving the problem]

[0004] Thus, in one aspect, there is provided a curable polybutadiene polymer comprising at least 60 wt. % of units derived from butadiene, preferably at least 80 wt. %, based on the total weight of the polymer, the polymer having a Mooney viscosity ML1+4 at 100° C. of 42 to 150 MU and a content of cis units of at least 96 wt. %, and the polymer has been treated with at least one modifier to introduce branching or folding of the polymer chain, and the modifier is selected from the group consisting of sulfur-containing modifiers, polysulfur-containing modifiers or combinations thereof, and the polymer is branched and has a degree of branching Δδ of 20 or less, and has a molecular weight of at least 1.0, preferably at least 1.0, based on the total weight of the polymer, and the polymer has a molecular weight of at least 1.0, preferably at least 1.0, based on the total weight of the polymer Mooney viscosity of polymer at 100°C ML1+4 / branching degree of polymer Δδ≧4.6 Meet the following.

[0005] In another embodiment, (i) a process for producing a polybutadiene polymer by a polymerization reaction preferably involving the presence of at least one neodymium-containing polymerization catalyst, the polymer having the following characteristics: a) branching degree Δδ of 21 or less; b) a Mooney viscosity at 100°C of at least 25 and less than 90 Mooney units, ML1+4; c) 1.50 MU * Shear sensitivity below g / kWs; and (ii) treating the reaction mixture with at least one modifier to increase branching and decrease the value of Δδ or increase the Mooney viscosity or shear sensitivity or both to provide the polymer described above, wherein the modifier is selected from the group consisting of sulfur-containing modifiers, polysulfur-containing modifiers, or combinations thereof; A process is provided that includes:

[0006] In a further aspect, there is provided an article comprising the above-described polybutadiene polymer in cured form, preferably the article is selected from a golf ball, a shoe sole, a hose, a belt, a tire or tire tread or another component of a tire.

[0007] In yet another aspect, a method of making an article is provided that includes subjecting a composition that includes a polybutadiene polymer and at least one curing agent for curing the polybutadiene polymer to curing and shaping, where the shaping can occur during, before, or after curing.

[0008] In another embodiment, there is provided a polymer composition comprising at least 60% by weight, preferably at least 95% by weight, of polybutadiene polymer, based on the total weight of the composition being 100%.

[0009] In a further embodiment, a rubber compound is provided comprising at least 5 wt. % polybutadiene polymer and further comprising at least one filler or at least one curative capable of curing the polymer, or a combination of at least one filler and at least one curative. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present disclosure will be further illustrated in the following detailed description.

[0011] In the following description, specific standards (ASTM, DIN, ISO, etc.) may be referenced. Unless otherwise specified, standards are used in the version that came into effect on March 1, 2020. If a version did not come into effect on that date, for example because the standard expired, the version referenced is the version that came into effect on the date closest to March 1, 2020.

[0012] All documents mentioned herein are incorporated by reference unless otherwise stated.

[0013] In the following description, the amounts of components of a composition or polymer may be interchangeably indicated by "weight percent", "wt.%" or "wt %". The terms "weight percent", "wt.%" or "wt %" are relative to the total weight of the composition or polymer, respectively, which is 100%, unless otherwise specified.

[0014] The term "phr" means "parts per hundred rubber", that is, the weight percentages of components of a composition containing one or more rubbers are percentages of the total amount of rubber, which is set to 100% by weight.

[0015] Ranges identified in this disclosure are meant to include and disclose all values ​​between the endpoints of the range, as well as the endpoints thereof, unless otherwise specified.

[0016] The terms "comprise", "contains" and "having" are used in an open, non-restrictive sense. For example, the phrase "a composition comprising components A and B" is meant to include components A and B, but the composition may also have other components. Contrary to the use of "comprise", "contains" or "having", the term "consisting of" is used in a narrow, restrictive sense. The phrase "a composition consisting of components A and B" is meant to describe a composition that includes components A and B and does not include other components.

[0017] Polybutadiene Polymer Composition The polybutadiene polymer composition according to the present disclosure comprises or consists of one or more polybutadiene polymers. In one embodiment of the present disclosure, the composition comprises at least 60 wt%, preferably at least 75 wt%, or at least 95 wt%, or at least 99 wt% of a polybutadiene polymer according to the present disclosure or a plurality of polybutadiene polymers according to the present disclosure, where "wt%" is the % relative to the total weight of the composition, which is 100%.

[0018] Polybutadiene polymers are curable and can be cured or crosslinked ("vulcanized") by reaction with a curing agent or a curing system that includes at least one curing agent to produce a vulcanized composition.

[0019] Polybutadiene polymers according to the present disclosure include homopolymers and copolymers of 1,3-butadiene. Preferably, the polybutadiene polymer comprises at least 60% by weight, preferably at least 80% by weight or at least 95% by weight, or even at least 99% by weight, of units derived from butadiene, where "% by weight" is based on the total weight of the polymer.

[0020] In one embodiment of the present disclosure, the polybutadiene polymer comprises 0% to 49% by weight, preferably 0% to 20% by weight, of units derived from one or more comonomers, based on the total weight of the polymer. Suitable comonomers include, but are not limited to, conjugated dienes having 5 to 24 carbon atoms, preferably 5 to 20 carbon atoms, other than butadiene. Specific examples include, but are not limited to, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 1-phenyl-1,3-butadiene, 1,3-hexadiene, myrcene, ocimene, farnesene, and combinations thereof. The comonomers may be functionalized at one or more positions to provide functional groups other than carbon-hydrogen bonds. Other such functional groups may include crosslinking sites, such as additional unsaturation, or polar functional groups. Suitable comonomers include, but are not limited to, one or more other copolymerizable comonomers that introduce branching into the polymer backbone, such as non-conjugated dienes, preferably non-conjugated α-ω bisolefins, more preferably α-ω bisdienes. Combinations of various comonomers may be used. In one embodiment of the present disclosure, the polybutadiene polymer contains 0-10 wt%, preferably 0-5 wt%, more preferably less than 1 wt% (based on the total weight of the polymer) of units derived from one or more comonomers.

[0021] The butadiene monomer or comonomer or both can be conventional materials, but can also be derived from sustainable materials, for example to reduce the carbon footprint. Sustainable materials include renewable or recycled materials. Renewable materials include, but are not limited to, monomers and comonomers produced by bacteria, which may or may not be genetically modified, or derived from plant-based materials. Recycled materials include, for example, monomers and comonomers derived from recycling carbonaceous waste materials by pyrolysis of plant-based materials, such as pulp or fiber, or carbonaceous waste materials, which may include carbonaceous waste materials.

[0022] The polybutadiene polymer according to the present disclosure may have a molecular weight distribution (MWD), i.e., a ratio of Mw / Mn, from 1.5 to 15. In one embodiment of the present disclosure, the polymer has an MWD of 1.5 to 7.5. or 1.5 to 4. In a preferred embodiment, the polymer has an MWD of 3.0 or less, for example, an MWD of 2.0 to 3.0.

[0023] The polybutadiene polymer according to the present disclosure may have a glass transition temperature (Tg) of from -120° C. to 0° C. In a preferred embodiment of the present disclosure, the polymer has a Tg of from -110 to -10° C., more preferably from -93 to -110° C.

[0024] The polymers according to the present disclosure may have a molecular weight (weight average Mw) of 100,000 to 2,500,000 g / mol. In one embodiment, the polymers have a Mw of 450 to 1,000 kg / mol. The polymers according to the present disclosure may have a number average molecular weight (Mn) of 105 to 650 kg / mol.

[0025] The polybutadiene polymer according to the present disclosure has a Mooney viscosity ML1+4 at 100° C. of 42-150 units, e.g., 55-130 or 60-129 units. In one embodiment of the present disclosure, polymers are provided having a low Mooney viscosity of 42-63 units, or e.g., 43-60 units or 46-58 units. In another embodiment of the present disclosure, the polymer has a Mooney viscosity of 63-150 units, e.g., 63-126 units, 64-92 units or 74-82 units. In one embodiment, the modified polymer according to the present disclosure has a Mooney viscosity of 63-94 units, preferably 63-86 units.

[0026] The curable polybutadiene polymers according to the present disclosure are branched and have a degree of branching, Δδ, of less than or equal to 20, preferably less than 19. For example, the polymers may have a Δδ of from 8 to 17, or even from 6 to 13. The lower the degree of branching, the more branched the polymer is.

[0027] The curable polymer according to the present disclosure preferably has a viscosity of at least 1.50 MU. *g / kWs, preferably at least 2MU * It has a shear sensitivity of g / kWs.

[0028] The polybutadiene polymer according to the present disclosure is preferably produced by polymerization using a polymerization catalyst or a catalyst system including at least one polymerization catalyst. After polymerization or towards the end of the polymerization, the polymer is subjected to treatment with one or more modifiers to increase the Mooney viscosity of the polymer, or its degree of branching, or its shear sensitivity, or a combination thereof. Suitable polymers can be produced using nickel catalysts, cobalt catalysts, titanium catalysts, or rare earth catalysts. Rare earth catalyzed polybutadiene polymers can contain more than 92% by weight of cis-1,4 units. During the polymerization reaction, butadiene monomers (CH2=CH-CH=CH2) can be incorporated into the growing polymer as "1,4-cis", "1,4-trans" and "1,2-vinyl" repeat units. A unit of the structure -CH2-CH=CH-CH2- is called a "1,4-cis unit" or "cis unit" when both -CH2 are on the same side of the double bond. When one of the -CH2 groups is on one side of the double bond and the other is on the other side of the double bond, the unit is called a "trans unit" or a "1,4-trans unit". A "vinyl unit" or a "1,2-vinyl unit" has the structure -CH2-CH(CH=CH2)-. The proportion of such units that make up a polymer is called the microstructure of the polymer. Polybutadienes having a microstructure represented by a high percentage of cis units, for example at least 92% cis units (by weight of the polymer), are usually desired because they improve the properties of the polymer.

[0029] Rare earth catalysts include catalysts containing neodymium, praseodymium, cerium, lanthanum, gadolinium and dysprosium, or combinations thereof. In a more preferred embodiment, polymerizations are carried out involving neodymium catalysts. Preferably, the polybutadiene polymer is prepared using a Ziegler-Natta type rare earth, preferably neodymium, catalyst composition. Typically, Ziegler-Natta type catalyst systems contain at least three components: a rare earth metal source (e.g., a neodymium source), a chloride source and an organoaluminum compound. Such catalyst systems are described, for example, in Canadian Patent Application No. 1,143,711A and U.S. Pat. No. 4,260,707, both of which are incorporated herein by reference. Metal sources include alkoxides, phosphates or carboxylates of catalytic metals (e.g., neodymium). Preferably, the metal source is represented by the formula (1): [ka] and wherein the metal carboxylate is selected from the group consisting of where M represents a rare earth metal selected from cerium, neodymium, praseodymium, gadolinium, lanthanum, preferably neodymium (Nd), and R may be the same or different. 1 , R 2 , and R 3 Each of R represents an alkyl group having 1 to 10 carbon atoms. 1 , R 2 , and R 3 The sum of all carbon atoms in is 6 to 20. A particularly preferred metal source is neodymium versatate. Combinations of various metal sources may also be used.

[0030] Suitable organoaluminum compounds include those of the formula Al(R 4 )3, Al(R 4 )H and Al(R 4 ) H2, wherein R 4represents an aliphatic or aromatic hydrocarbon, preferably an alkyl group having 1 to 10 carbon atoms, preferably ethyl or isobutyl. Specific examples include, but are not limited to, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum (TIBA), tri-t-butylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, and dihydrocarbylaluminum hydrides, such as diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride (DIBAH), di-n-octylaluminum hydride, diphenylaluminum hydride, di-p-tolylaluminum hydride, dibenzylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride. aluminum hydride, phenylisobutylaluminum hydride, phenyl-n-octylaluminum hydride, p-tolylethylaluminum hydride, p-triyl-n-propylaluminum hydride, p-triylisopropylaluminum hydride, p-triyl-n-butylaluminum hydride, p-triylisobutylaluminum hydride, p-triyl-n-octylaluminum hydride, benzylethylaluminum hydride, benzyl-n-propylaluminum hydride, benzylisopropylaluminum hydride, benzyl-n-butylaluminum hydride, benzylisobutylaluminum hydride, benzyl-n-octylaluminum hydride, and the like; and dihydrocarbylaluminum dihydrides such as ethylaluminum dihydride, n-propylaluminum dihydride, isopropylaluminum dihydride, n-butylaluminum dihydride, isobutylaluminum dihydride, and n-octylaluminum dihydride, and combinations thereof. Preferred organoaluminum compounds include diisobutylaluminum hydride.

[0031] The chloride source is preferably selected from alkylaluminum chlorides, such as, but not limited to, diethylammonium chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, and combinations thereof.

[0032] The catalyst composition may further contain and be practiced with a conjugated diene. The catalyst system may be partially or completely practiced, i.e., formed before it is added to the polymerization reactor, or its components may be added directly to the polymerization reactor, either simultaneously or sequentially, preferably dissolved in a solvent.

[0033] Polymers produced with neodymium-based catalysts or Nd catalyst systems (Nd-catalyzed polybutadiene) typically have a cis unit content of at least 92%, or at least 94%, or at least 95%, or preferably at least 96%. In one embodiment of the present disclosure, the polymer is produced with a neodymium-based catalyst using a Ziegler-Natta type neodymium catalyst composition comprising a neodymium catalyst, a chloride source, and an organoaluminum hydride, preferably the polymer has a cis unit content of greater than 92% weight percent, greater than 94% weight percent, or even greater than 96% weight percent.

[0034] The polymerization is preferably carried out as a solution polymerization. The typical reaction temperature of the polymerization is 60-140°C. Suitable inert solvents include, for example, aromatic, aliphatic and cycloaliphatic hydrocarbons. Specific examples include, but are not limited to, benzene, toluene, pentane, n-hexane, isohexane, heptane, pentane isomers, methylcyclopentane and cyclohexane. The solvents can be used individually or in combination with one or more polar solvents or can be blended. The inert organic solvent can be used at 200-900 parts by weight per 100 parts by weight of monomer. The polymerization can be carried out continuously or batchwise. Processes known in the art can generally be followed, for example the industrial processes described in (Patent Document 1) and (Patent Document 2), and measures can be taken to form the branches of the polymer, since the polymer used for the modification with sulfur-based modifiers is preferably already branched before its modification with the sulfur-containing modifier. Polymerization with rare earth catalysts generally forms linear polymers, but branched polymers can be produced by variations to known processes. For example, polymer branches can be formed by polymerization at elevated temperatures (thermally induced branching) for a sufficient time (polymer conversion) as described, for example, in US Patent Publication No. 2013 / 0172489A1. Another method involves the use of branch-inducing comonomers in the polymerization reaction, such as conjugated dienes, such as α-ω poly- or bis-olefins, such as α-ω dienes. Yet another method can involve adjusting the components and amounts of the catalyst system, as described, for example, in US Patent Publication No. 2011 / 112261A1.

[0035] By forming polymer branches in situ, i.e. during polymerization, the branches are linked to the polymer by carbon-carbon bonds and not through heteroatoms. It is not suitable for producing polymers according to the present disclosure, where the method was used to form polymer branches, except that the branching preferably occurs during polymerization and / or the branches are preferably linked to the polymer backbone by carbon-carbon bonds. Preferably, the polymer before modification with the sulfur-based modifier has a branching degree (Δδ) of 21 or less, for example 19 or less. Typical ranges of Δδ include 10-21, or 15-21. By treatment with a sulfur-based modifier, the branching can be further increased and Δδ can be reduced. After modification with one or more sulfur-based modifiers, the polymer has a Δδ of 20 or less, preferably less than 19. For example, the polymer resulting from the modification process can have a Δδ of 8-17 or even 6-13.

[0036] The treatment with sulfur-based modifiers can increase the Mooney viscosity of the polymer. The polymers subjected to modification with sulfur-based modifiers preferably have a Mooney viscosity ML1+4 at 100°C of at least 25 and less than 90 Mooney units, preferably less than 72 Mooney units (MU). The modification treatment is carried out so that the Mooney viscosity of the final polymer can be increased to the above-mentioned final polymer Mooney viscosity ML1+4 at 100°C, for example, but not limited to, a Mooney viscosity of 42 to 150 units, such as 55 to 130 or 60 to 129 units. In one embodiment of the present disclosure, modified polymers are provided having a low Mooney viscosity of 42 to 63 units. In another embodiment of the present disclosure, modified polymers are provided having a Mooney viscosity of 63 to 150 units, such as 63 to 126 units. In one embodiment, the modified polymers according to the present disclosure have a Mooney viscosity of 63 to 94 units, preferably 63 to 86 units.

[0037] Preferably, the polymer before modification with the sulfur-based modifier has a molecular weight of 2MU. * Less than g / kWs, preferably 1.5MU *Preferably, the modification treatment increases the shear sensitivity of the polymer. Preferably, the modified polymer according to the present disclosure, i.e., the polymer obtained after modification with a sulfur-based modifier, has a shear sensitivity of at least 1.50 MU. * g / kWs, preferably at least 2MU * It has a shear sensitivity of g / kWs.

[0038] In one embodiment of the present disclosure, there is provided a process for producing a modified polybutadiene polymer according to the present disclosure, comprising: (i) a process for producing a polybutadiene polymer by a polymerization reaction preferably involving the presence of at least one neodymium-containing polymerization catalyst, wherein the polymer has the following characteristics: a) branching degree Δδ less than or equal to 21; b) a Mooney viscosity at 100°C of at least 25 and less than 90 Mooney units, ML1+4; c) 1.50 MU * Shear sensitivity below g / kWs; and (ii) treating the reaction mixture with at least one modifier to increase branching and reduce the value of Δδ or increase the Mooney viscosity or shear sensitivity or both to provide a modified polymer according to the present disclosure, wherein the modifier is selected from the group consisting of sulfur-based modifiers, polysulfur-based modifiers, or combinations thereof; A process is provided that includes:

[0039] The process does not require the use of phosphoric acid esters as disclosed in

[0039] to

[0046] of (Patent Document 4), which are incorporated herein by reference. Preferably, the polymer according to the present disclosure is essentially phosphorus-free, preferably having a phosphorus content of less than 210 ppm, including 0 ppm, preferably less than 200 ppm, including 0 ppm. The amount of phosphorus can be determined, for example, as described in

[0182] of (Patent Document 4).

[0040] Sulfur-based modifiers can be used in the art, for example, as described in U.S. Pat. Nos. 9,845,366, 9,963,519 and 5,567,784. Treatment with sulfur-containing modifiers can incorporate sulfur atoms into polymers and form sulfur-carbon bonds in the polymer. The terms "sulfur-based modifier" and "sulfur-containing modifier" are used interchangeably herein. They both refer to modifiers that contain sulfur.

[0041] The amount of sulfur bound to the polymer can be determined by measuring the sulfur content after the polymer has been subjected to extraction. The polybutadiene polymer according to the present disclosure may have a content of polymer-bound sulfur of about 12 to about 20,000 ppm, preferably about 20 to about 2,000 ppm, or 200 to 3,000 ppm, based on the total weight of the polymer (measured after Soxhlet extraction of 1 g of polymer sample with 50 mL of acetone (>99% purity) under reflux for 48 hours). Extraction can be performed to distinguish between polymer-bound sulfur and sulfur that is not bound to the polymer but may be present in the composition as part of a stabilizer such as an antioxidant. The extraction described in the experimental section removes additive-derived sulfur.

[0042] The modified polymer is branched as a result of treatment with a modifier. However, since the polymer that is subjected to the modification is already branched as a result of the polymerization conditions, the final polymer has at least two different types of polymer branches. The type of branch that is generated by treatment with one or more sulfur-based modifiers can lead to polymer chains that are linked to other polymer chains via sulfur or polysulfur bridges. The other type of branch that is generated during polymerization is based on carbon-carbon bonds that result from polymerization.

[0043] The modification treatment can be preferably carried out in the reaction mixture, preferably after the polymerization has been stopped, and preferably before the work-up procedure. Preferably, the treatment is carried out in the reaction mixture. The polymerization can be stopped before or after the treatment with the sulfur-based modifier, for example by adding a material that deactivates the catalyst. Such materials include, for example, protic materials such as organic acids. The modifier can be added at the same temperature as the polymerization temperature, or at a higher or lower temperature. For example, the modifier can be added without the need to increase or decrease the reaction temperature, or after degassing as described in the above references. The sulfur-based modifier can be added as a pure substance or as a solution, and can be added as a solid, liquid, or as a spray. The addition of the modifier can be carried out in the same polymerization reactor or in a different reactor or pipe. The amount of modifier used depends on the final branching degree Δδ and Mooney viscosity to be achieved, as well as the initial branching degree and Mooney viscosity of the polymer. The appropriate amount is selected to achieve the desired Δδ and Mooney viscosity, and preferably also the desired shear sensitivity. Preferably, an appropriate amount of one or more sulfur modifiers is used to increase the Mooney viscosity and / or reduce the branching Δδ such that the quotient value of Mooney viscosity ML1+4,100°C / polymer Δδ is 4.6-46, or 4.6-26, or 4.6-14. In one embodiment of the present disclosure, the polymer has a ratio of polymer Mooney viscosity ML1+4,100°C / polymer Δδ of 4.6-8.8 or 4.9-8.7. Typical amounts of modifiers may include 0.005-2 parts by weight / 100 parts of polymer, or 0.007-0.5 parts / 100 parts of polymer, or 0.1-0.4 parts / 100 parts of polymer. Suitable sulfur-containing modifiers include sulfur halides, more preferably sulfur bromides and sulfur chlorides and polysulfur halides. Preferably, the sulfur-containing modifier has 1-8 sulfur atoms / molecule, preferably 1 or 2 sulfur atoms / molecule. Suitable examples include, but are not limited to, S2Cl2, SCl2, SOCl2, S2Br2, SOBr2. It is contemplated that functionalized sulfur-based modifiers containing a functional group R may also be used.Examples of such modifiers are described in US 2016 / 0280815 A1. Another approach to introducing functional groups into the polymer can be achieved by functionalizing the polymer with a polar comonomer prior to treatment with a sulfur-based modifier, for example as described in EP 2819853 B1. In one embodiment of the present disclosure, the polymer does not have any functional groups other than those formed by the sulfur-based modifier, and is preferably not further functionalized to contain any organic groups, i.e., groups having carbon and hydrogen atoms. In one embodiment, the polymer does not have any functionalized end groups, at least the functionalized end groups and / or in-chain are not generated by one or more functionalizing agents other than the sulfur-based modifier.

[0044] The modified polymer can be provided as a solution in a solvent or mixture of solvents. The modified polymer can be isolated, as known in the art, for example, by removing the solvent, for example, by stripping, for example, by stream stripping, or by coagulation, achieved, for example, by adding a liquid in which the polymer is not soluble. The recovered solvent and monomer can be recycled. The polymer can be dried, shaped into granules, pressed into bales, or used as crumbs or powders, as known in the art. Thus, in one embodiment according to the present disclosure, a composition is provided that comprises at least 60% by weight, preferably at least 75% by weight, or at least 95% by weight, of a polybutadiene or two or more polybutadienes according to the present disclosure, the weight percentage being the percentage relative to the total weight of the composition, which is 100%. The composition can be a liquid or solid composition, preferably in the form of granules, bales, powders, or sheets. The polybutadiene polymer according to the present disclosure can optionally be an oil extended polymer. This means that one or more extenders can be added to the polymer, preferably to the reaction mixture. Suitable extenders include process oils, which are known in the art and are further described below. Thus, in one embodiment according to the present disclosure, there is provided a composition, wherein the polybutadiene polymer is an oil-extended polymer, and the composition comprises at least 60% by weight, preferably at least 75% by weight, or at least 95% by weight of the polybutadiene or two or more polybutadienes according to the present disclosure, and one or more extender oils, the weight percentage being based on the total weight of the composition being 100%.

[0045] Compound A composition containing at least one polybutadiene polymer according to the present disclosure may be used to prepare a rubber compound. Accordingly, in another aspect of the present disclosure, a rubber compound is provided that includes a polymer according to the present disclosure, preferably in an amount of at least 5% by weight, based on the total weight of the compound. The rubber compound may typically contain 5-75% by weight, or 7-50% by weight, of the polybutadiene polymer of the present disclosure, based on the total weight of the compound.

[0046] The rubber compound may further contain at least one filler. The rubber compound according to the present disclosure may contain at least 10% by weight, preferably at least 15% by weight, of one or more fillers, based on the weight of the compound.

[0047] The rubber compound may be, for example, in the form of a powder, granules, extruded pellets, sheets or bales, and may further contain one or more rubber co-agents, one or more curing agents, and / or one or more rubbers other than the hydrogenated butadiene polymer, as described below.

[0048] Filler Preferably, the compound comprises at least one filler suitable for application in tires, materials for constructing tires, and materials for manufacturing tires. Preferably, the filler comprises one or more silicas, one or more carbon blacks, or a combination of one or more carbon blacks and one or more carbon blacks. Preferably, the filler has a density of 5 to 1,000 m. 2 / g, preferably 20 to 400m 2The fillers include silica-containing particles, preferably having a BET surface area (nitrogen absorption) of 20 to 400 m / g. Such fillers can be obtained, for example, by precipitation from a solution of silicates or by flame hydrolysis of silicon halides. The silica particles can have a particle size of 10 to 400 nm. The silica-containing fillers can also contain oxides of Al, Mg, Ca, Ba, Zn, Zr or Ti. Other examples of silicon oxide-based fillers include aluminum silicates, alkaline earth metal silicates, for example, preferably having a BET surface area of ​​20 to 400 m. 2 Examples of fillers include magnesium or calcium silicates having a molecular weight of 100 / g and a primary particle size of 10-400 nm, natural silicates such as kaolin, and other natural silicates such as clays (layered silica). Further examples of fillers include glass particle-based fillers such as glass beads, microspheres, glass fibres and glass fibre products (mats, strands).

[0049] Polar fillers, such as silica-containing fillers, can be modified to make them more hydrophobic. Suitable modifiers include silanes or silane-based compounds. Common examples of such modifiers include, but are not limited to, those represented by the general formula (V): (R 1 R 2 R 3 O)3Si-R 4 -X(V) Compounds corresponding to the following formula are also included: In the formula, R 1 , R 2 , R 3 are each independently an alkyl group, preferably R 1 , R 2 , R 3 are all methyl or all ethyl, R 4 is an aliphatic or aromatic linking group having 1 to 20 carbon atoms, and X is a sulfur-containing functional group and is selected from -SH, -SCN, -C(=O)S, or a polysulfide group.

[0050] Instead of or in addition to silica modified as described, such modification can also be carried out in situ when producing a rubber compound, for example by adding a modifier, preferably a silane or silane-based modifier, such as a compound according to formula (V), during compounding or during the process of producing a tire or a component thereof.

[0051] Fillers based on metal oxides other than silicon oxide include, but are not limited to, zinc oxide, calcium oxide, magnesium oxide, aluminum oxide, and combinations thereof.Other fillers include metal carbonates such as magnesium carbonate, calcium carbonate, zinc carbonate, and combinations thereof, metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and combinations thereof, α-β-unsaturated fatty acids having 3 to 8 carbon atoms and salts of acrylic or methacrylic acid such as zinc acrylate, zinc diacrylate, zinc methacrylate, zinc dimethacrylate, and mixtures thereof.

[0052] In another embodiment of the present disclosure, the rubber compound contains one or more fillers based on carbon, such as one or more carbon blacks. The carbon blacks can be produced, for example, by the lamp black process, the furnace black process, or the gas black process. Preferably, the carbon black has a BET surface area (nitrogen absorption) of 20 to 200 m. 2 / g. Suitable examples include, but are not limited to, SAF, ISAF, HAF, FEF and GPF Black.

[0053] Other examples of suitable fillers include carbon-silica dual phase fillers, lignin or lignin based materials, starch or starch based materials, and combinations thereof.

[0054] In a preferred embodiment, the filler comprises one or more of silica, carbon black, or a combination thereof.

[0055] Typical amounts of filler include from 5 to 200 parts per 100 parts of rubber, such as from 10 to 150 parts by weight, or from 10 to 95 parts by weight, based on 100 parts total weight of rubber.

[0056] Fillers from renewable or sustainable resources may be used, for example silica materials obtained from plants, such as rice husks, including rice husks. Carbon-based fillers are obtained, for example, from recycled materials.

[0057] Hardener: Preferably, the rubber compound also contains at least one curing agent for curing the polybutadiene polymer. The curing agent can crosslink (cure) the polymer and is also referred to herein as a "crosslinking agent" or "vulcanizing agent". Suitable curing agents include, but are not limited to, sulfur, sulfur-based compounds, and organic or inorganic peroxides. In a preferred embodiment, the curing agent includes sulfur. Instead of a single curing agent, a combination of one or more curing agents may be used, or a combination of one or more curing agents with one or more curing accelerators or curing catalysts may be used. Examples of sulfur-containing compounds that act as sulfur donors include, but are not limited to, sulfur, sulfur halides, dithiodimorpholine (DTDM), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), and dipentamethylenethiuram tetrasulfide (DPTT). Examples of sulfur accelerators include, but are not limited to, amine derivatives, guanidine derivatives, aldehyde amine condensation products, thiazoles, thiuram sulfides, dithiocarbamates and thiophosphates. Examples of peroxides used as vulcanizing agents include, but are not limited to, di-t-butyl-peroxide, di-(t-butyl-peroxy-trimethyl-cyclohexane), di-(t-butyl-peroxy-isopropyl-)benzene, dichlorobenzoyl peroxide, dicumyl peroxide, t-butyl-cumyl-peroxide, dimethyl-di(t-butyl-peroxy)hexane and dimethyl-di(t-butyl-peroxy)hexyne and butyl valerate-di(t-butyl-peroxy). Sulfenamide, guanidine or thiuram type vulcanizing accelerators can be used together with the vulcanizing agent as needed.

[0058] If added, the vulcanizing agent is generally present in an amount of from 0.5 to 10 parts by weight, preferably from 1 to 6 parts by weight, per 100 parts by weight of rubber.

[0059] Other Rubber Rubber compounds and compositions according to the present disclosure may contain one or more additional rubbers other than the polybutadiene polymers of the present disclosure. Examples of such other rubbers include, but are not limited to, high vinyl polybutadiene (i.e., at least 10% vinyl by weight), C1-C4 alkyl acrylates, copolymers of chloroprene and butadiene, polyisoprene, styrene-butadiene copolymers, isobutylene-isoprene copolymers, butadiene-acrylonitrile copolymers, such as copolymers having an acrylonitrile content of 5-80% by weight, such as copolymers having an acrylonitrile content of 10-40% by weight; partially or fully hydrogenated acrylonitrile rubber, ethylene-propylene-diene copolymers, natural rubber, and combinations thereof. Typical amounts of one or more other rubbers in the compound include, for example, 5-500 parts per 100 parts of polybutadiene polymer.

[0060] In a preferred embodiment of the present disclosure, the rubber compound contains at least one styrene-butadiene copolymer, preferably in an amount of 5 to 65 wt.%, or 10 to 50 wt.%, based on the total weight of the compound. The styrene-butadiene copolymer may be modified to contain one or more functional groups containing one or more atoms selected from Si, O, N and S atoms, preferably the functional groups containing Si and O atoms. In the case of α, ω or α and ω functionalization, the functional groups may be located at the terminal positions of the polymer, as described, for example, in WO 2021 / 009156 A1; US ​​2016 / 0083495 A1 and US 2016 / 0075809 A1, and European Patent Application No. 2847264 A1, all of which are incorporated herein by reference. The functional group may be a pendant group, for example, as part of a functional group within the chain, by treatment with a mercapto acid, or a mercapto polyether, as described, for example, in U.S. Pat. No. 6,521,698 B2, incorporated herein by reference. Other suitable polymers that may be blended with the polymers according to the present disclosure include those described in U.S. Pat. No. 6,399,623. The combination of such functionalized styrene-butadiene rubbers in tire compositions with silica fillers or carbon-based fillers or both may improve dynamic properties, particularly those expressed by tan d 0° C. / tan d 60° C., as well as tensile properties such as S300, S300 / S100, tensile strength or elongation at break, or a combination thereof. Typical weight ratios of the polymers according to the present disclosure to the functional polymer include ratios of 3:1 to 1:3.

[0061] Other rubber auxiliaries: The compositions and rubber compounds containing polybutadiene polymers according to the present disclosure may contain one or more additional rubber auxiliaries known in the art for rubber compounding and processing. Such additional auxiliaries include, but are not limited to, cure accelerators, antioxidants, heat stabilizers, light stabilizers, processing aids, plasticizers, tackifiers, blowing agents, and colorants. Processing auxiliaries include organic acids, waxes, and process oils. Examples of oils include, but are not limited to, MES (light extractive solvates), TDAE (treated distillate aromatic extracts), RAE (residual aromatic extracts), and naphthenic light and heavy oils, as well as vegetable oils. Specific examples of commercially available oils include oils having the trade names Nytex 4700, Nytex 8450, Nytex 5450, Nytex 832, Tufflo 2000, and Tufflo 1200. Examples of oils include functionalized oils, particularly epoxidized or hydroxylated oils.

[0062] Activators include triethanolamine, polyethylene glycol, hexanetriol.Colorants include dyes and pigments and can be organic or inorganic, such as zinc white and titanium dioxide.

[0063] Additional rubber auxiliaries may be used in suitable amounts depending on the intended use as known in the art. Typical amounts of auxiliaries individually or in total include 0.1 to 50% by weight based on the total weight of rubber in the compound.

[0064] To produce the rubber compound, the polybutadiene polymer composition according to the present disclosure can be blended with one or more of the components by means known in the art of rubber processing, for example, by using rolls, internal mixers and mixing extruders. The filler is preferably mixed into the solid polybutadiene polymer composition or into mixtures thereof with other rubbers known in the art, for example, using a kneader. The filler can be added as a solid, or as a slurry, or in another state known in the art.

[0065] vulcanizate The rubber vulcanizates can be obtained by subjecting the rubber compound, i.e. the composition comprising the polybutadiene polymer of the present disclosure and at least one curing agent, to curing, e.g. one or more curing steps. The curing can be carried out as known in the art. The curing is generally carried out at a temperature of 100-200°C, e.g. 130-180°C. The curing can be carried out in a mould under reduced pressure. Typical pressures include pressures of 10-200 bar. The curing times and conditions vary depending on the actual composition of the rubber compound and the amount and type of the curing agent and curable components.

[0066] Goods The compositions and compounds according to the present disclosure can be used to manufacture articles. Typically, the articles include the polybutadiene polymer compositions according to the present disclosure in a cured state, for example, as a result of one or more curing reactions. The compositions and compounds provided in the present disclosure are particularly suitable for manufacturing tires or tire components. Tires include pneumatic tires. Tires include tires for automobiles, aircraft, and electric and hybrid vehicles, i.e., vehicles that can be driven by a combustion engine or an electric propulsion engine or a battery. Typical components of tires include innerliners, treads, undertreads, carcasses, and sidewalls.

[0067] In one embodiment, the compositions and compounds according to the present disclosure are used as sealing materials, for example to make O-rings, gaskets or any other seal or sealing component.

[0068] In one embodiment, the compositions and compounds according to the present disclosure are used as impact modifiers for thermoplastic materials such as polystyrene and styrene-acrylonitrile.

[0069] In another embodiment, the compositions and compounds according to the present disclosure are used to manufacture golf balls or components thereof. In another embodiment, the compositions and compounds according to the present disclosure are used to manufacture shaped articles selected from profiles, membranes, damping elements and hoses. The articles may be obtained by subjecting the curable rubber compounds of the present disclosure to curing and shaping. The shaping step may take place during or after the curing step, or even before the curing step. A single curing and / or shaping step may be used, or multiple curing and / or shaping steps may be used. Additional ingredients may be added to the compositions of the present invention as required for the manufacture of the article.

[0070] Thus, in one aspect of the present disclosure, an article is provided that includes a polybutadiene polymer according to the present disclosure in a cured form. Preferably, the article is selected from a golf ball, a shoe sole, a hose, a belt, a tire or tire tread, or another component of a tire. In another aspect of the present disclosure, a method of manufacturing an article is provided that includes subjecting a composition according to the present disclosure, comprising at least one curable polybutadiene according to the present disclosure and at least one curing agent for curing the polybutadiene polymer, to curing and shaping, where shaping can occur during, before, or after curing.

[0071] Hereinafter, the present disclosure will be further illustrated by specific embodiments and examples, but it is not intended that the present disclosure be limited to these specific embodiments and examples.

[0072] method Cis, trans and vinyl unit content: The content of vinyl, cis and trans units in a polymer can be determined by Fourier transform infrared (FT-IR) spectroscopy using absorbance and absorbance ratios as described in the standard ISO 12965:2000(E).

[0073] Mooney Viscosity: The Mooney viscosity of the polymers was determined according to standard ASTM D1646 (1999) using a 1999 Alpha Technologies MV2000 Mooney Viscometer.

[0074] Mooney Stress Relaxation (MSR): Mooney stress relaxation (MSR) was determined according to ASTM D1646-00 at a temperature of 100°C.

[0075] Molecular weight and molecular weight distribution: Molecular weights (number average molecular weight (Mn), weight average molecular weight (Mw)) and molecular weight distribution (MWD=Mw / Mn) were determined by gel permeation chromatography (GPC). A modular system from Agilent, Santa Clara, CA, USA, equipped with an Agilent 1260 refractive index detector, an Agilent 1260 variable wavelength detector, a 1260ALS autosampler, a column oven (Agilent 1260TCC), an Agilent 1200 Degasser, an Agilent 1100 Iso pump and a column combination of 3PLgel 10 μm Mixed B300×7.5 mm columns from Agilent was used. Tetrahydrofuran (THF) was used as the solvent. Polystyrene standards from PSS Polymer Standards Service GmbH (Mainz, Germany) were used. The polymer samples dissolved in THF were filtered through a syringe filter (0.45 μm PTFE membrane, 25 mm diameter). Measurements were performed at 40° C. and a flow rate of 1 mL / min.

[0076] Glass Transition Temperature: Glass transition temperatures (Tg) were determined by differential thermal analysis (DTA, differential scanning calorimetry (DSC)) on a 2003 Perkin Elmer DSC-7 calorimeter. 10-12 mg of polymer was placed on a DSC sample holder (standard aluminum pan) commercially available from Perkin Elmer. Two cooling / heating cycles were performed and the Tg was determined in the second heating cycle. The first DSC cycle was performed by first cooling the sample to -100°C with liquid nitrogen and then heating it to +150°C at a rate of 20 K / min. As soon as a sample temperature of +150°C was reached, the second DSC cycle was started by cooling the sample at a cooling rate of about 320 K / min. In the second heating cycle, the sample was heated again to +150°C at a heating rate of 20 K / min. From the graph of the DSC curve of the second heating run, the Tg was determined.

[0077] Polymer-bound Sulfur Content: 1 g of polymer sample was cut into smaller pieces and extracted with 50 mL of acetone (>99% purity) by Soxhlet extraction under reflux for 48 h. After extraction, the polymer was dried in a vacuum oven at 60° C. Subsequent quantification of the sulfur content (bound sulfur) is performed by combustion ion chromatography (CIC). CIC instruments are commercially available, for example, from Thermo Fisher Scientific (e.g. Fisher Scientific GmbH, Schwerte, Germany). They usually have two connected units; one is an automatic digestion unit with an autosampler, a combustion unit (electric heater) and an absorption module. The second unit is an ion chromatography unit for quantification. For the measurement, the polymer sample is weighed into a ceramic boat and then thermohydrolytically oxidized in an argon-oxygen atmosphere. The sample gas is absorbed in a hydrogen peroxide solution and automatically transferred to an ion chromatograph, where sulfur is measured as sulfate anion.

[0078] Branching degree (Delta delta, Δδ): The degree of branching was determined with a SIS V50 Rubber Processability Analyzer (RPA) in frequency mode consisting of 20 frequencies (equidistant on a logarithmic scale) starting at 0.01-40 Hz, temperature 100°C and amplitude 0.5°. Polyamide-6,6 foil was used. After 5 min preheating, measurements were performed with 3 pre-cycles and 3 measurement cycles / times. Delta delta (Δδ) is the difference in phase angle delta at 0.1 and 100 rad / s.

[0079] Shear Sensitivity: The shear sensitivity was measured on a commercial intermeshing mixer GK1.5E from Werner & Pfleiderer equipped with a PES 5 rotor. The mixer was preheated to 80°C, then the test material was charged to 72% of the mixer and mixed at 50 rpm for 3 minutes. The test material was discharged and the Mooney viscosity of the test material was measured. The specific mixing energy of the mixing step was measured. This procedure was repeated with a new sample of the test material for 5 minutes. Then, a mixing time of 8 minutes was repeated with a new sample of the test material, and a mixing time of 12 minutes was repeated with a new sample of the test material.

[0080] The shear sensitivity (MU) was then calculated as the absolute value of the slope of the linear regression curve obtained by plotting the Mooney viscosity of the polymer against the corresponding specific mixing energy. * Specific mixing energy values ​​below 0.5 kWs / g and mixing energy values ​​with a Mooney reduction of more than 15% relative to the initial Mooney viscosity before treatment were not taken into account for the linear regression.

[0081] MV / Δδ ratio: The ratio is calculated from the measurements taken for Mooney Viscosity (MV) and degree of branching Δδ. The average value from three measurements was used. The Mooney units used in the calculation included one decimal place. The Δδ values ​​used in the calculation included one and two decimal places.

[0082] Properties of hardening compounds Mooney Viscosity: The Mooney viscosity of the curable compounds (measurement conditions ML(1+4) at 100° C.) was determined according to ISO 289-1 on an Alpha Technology Mooney MV2000 from 1999.

[0083] Monsanto MDR: Monsanto MDR was determined according to ISO6502 on an Alpha Technology rheometer MDR 2000E.

[0084] Properties of vulcanized polymers and compounds hardness: The Shore A hardness at 60° C. was determined in accordance with DIN 53505.

[0085] Resilience: The rebound resilience at 60° C. was determined in accordance with DIN 53512.

[0086] Mechanical stress: Stress values ​​at 10%, 100% and 300% elongation (σ10, σ100 and σ300), tensile strength and elongation at break were determined according to DIN 53504 in an S2 test fixture at 10 kN on a roboTest R robotic testing system commercially available from ZwickRoelln, Ulm, Germany.

[0087] wear: The wear was determined according to DIN 53516.

[0088] Dynamic properties: The dynamic properties were determined according to DIN 53513-1990 on an Eplexor 500N from Gabo-Testanlagen GmbH, Ahlden, Germany, at 10 Hz in the temperature range from -100 °C to +100 °C, with a heating rate of 1 K / min, with a constant strain of 0.9% and a dynamic strain of 0.1% (samples: strips of length x width x height = 60 mm x 10 mm x 2 m; free length between sample holders 30 mm). The following properties were thus determined: E'(60 °C): storage modulus at 60 °C; E'(23 °C): storage modulus at 23 °C; E'(0 °C): storage modulus at 0 °C; tan δ(60 °C), i.e. loss factor at 60 °C (E'' / E'); tan δ(23 °C), i.e. loss factor at 23 °C (E'' / E') and tan δ(0 °C), i.e. loss factor at 0 °C (E'' / E'). E' provides an index of the grip of a winter tire tread on ice and snow. A decrease in E' improves grip. Tan δ(60°C) is a measure of the hysteresis loss from the tire under driving conditions. A decrease in tan δ(60°C) reduces the rolling resistance of the tire. Tan δ(0°C) is a measure of the wet grip of a material. An increase in tan δ(0°C) increases wet grip.

[0089] Elasticity: Elasticity was determined according to DIN 53513-1990. An elastomer testing system (MTS Systems GmbH, 831 Elastomer testing system) was used. Measurements were carried out in double shear mode on cylindrical specimens (2 specimens precompressed to 20 x 6 mm each, 5 mm thick) without static pre-strain in the shear direction, at approximately zero oscillations, and with a measurement frequency of 10 Hz in the strain range of 0.1 to 40%. Using this method, the following properties were obtained: G'(0.5%): dynamic modulus of elasticity at 0.5% amplitude sweep, G'(15%): dynamic modulus of elasticity at 15% amplitude sweep, G'=G'(0.5%)-G'(15%): difference in dynamic modulus of elasticity at 0.5% relative to 15% amplitude sweep, tan δ(max): maximum loss factor (G'' / G') over the entire measurement range at 60°C.

[0090] The difference G'(0.5%)-G'(15%) is an indication of the Payne effect of the mixture. The lower the value, the better the distribution of the filler in the mixture and the better the rubber-filler interaction, the lower the risk of phase separation. Tan δ(max) is another measure of the hysteresis loss from the tire under driving conditions. A decrease in tan δ(max) reduces the rolling resistance of the tire. EXAMPLES

[0091] The polymers of Comparative Examples C1 and C2 were polybutadiene rubbers that were not treated with modifiers to increase their Mooney viscosity. The polymer of Comparative Example C3 was subjected to treatment with modifiers and had a Mooney viscosity similar to that of the polymer of Comparative Example C2. For Examples 1-5, polybutadienes with higher branching than C3 were used. They were also treated with modifiers to reach MV / Δδ ratios above 4.6. All polymers were produced with the same Nd-based catalyst system and had a 1.4 cis content of more than 96 wt%. The modifier was S2Cl2, and the modification was carried out by adding 0.025-0.135 g per 100 g of polymer to the reaction mixture (50-110°C for 10-300 min) depending on the degree of branching and Mooney viscosity.

[0092] [Table 1]

[0093] Several compounds were prepared with the components and amounts shown in Table 2 for Comparative Examples 2 and 3 (C2 and C3) and Examples 1 to 5 (Ex1 to Ex5).

[0094] [Table 2]

[0095] The resulting compounds have Mooney viscosities as shown in Table 3.

[0096] [Table 3]

[0097] The compounds were cured at 160°C and the cure time was set based on the T95 value of the rheometer cure time. The properties of the cured compounds are shown in Tables 4 and 5.

[0098] [Table 4]

[0099] [Table 5]

[0100] Comparison of Comparative Examples C4 and C5 confirms that the modification (C5) improves processability (reduced Mooney viscosity of the compound) and improves wear properties compared to the unmodified polymer (C4).

[0101] Comparison of the examples according to the present disclosure (Examples 6-10) with Comparative Example C5 demonstrates that modification of the polymer to reach a MV / Δδ ratio greater than 4.5 increases the performance of the modified polymer, in particular the tan d 0°C value (wet grip index) and the ratio of tan d 0°C / tan d 60°C (wet grip vs. rolling resistance). The Payne effect (G'(0.5%)-G'(15%)) is significantly improved, indicating excellent filler dispersion.

Claims

1. 1. A curable polybutadiene polymer comprising at least 60% by weight, preferably at least 80% by weight, of units derived from butadiene, based on the total weight of the polymer, said polymer having a Mooney viscosity ML1+4 at 100° C. of 42-150 MU and a cis unit content of at least 96% by weight, said polymer having been treated with at least one modifier to introduce branching and folding of the polymer chain, said modifier being selected from the group consisting of sulfur-containing modifiers, polysulfur-containing modifiers or combinations thereof, said polymer being branched and having a degree of branching Δδ of 20 or less, and having a molecular weight of at least 100% by weight, said molecular weight being ... Mooney viscosity of the polymer at 100° C. ML1+4 / branching degree of the polymer Δδ≧4.6 A curable polybutadiene polymer which satisfies the above requirements.

2. 2. The polymer of claim 1, wherein the polybutadiene polymer has a Mooney viscosity ML1+4 at 100° C. of 63 to 150 Mooney units or a Mooney viscosity ML1+4 at 100° C. of 44 to 63 Mooney units.

3. 3. The polymer of claim 1 or 2, wherein the polybutadiene polymer is produced by a polymerization reaction involving at least one neodymium-containing polymerization catalyst.

4. 4. The polymer of any one of claims 1 to 3, wherein the sulfur-containing modifier comprises a sulfur halide having 1 to 8 sulfur atoms per molecule.

5. The sulfur-containing modifier is S ２ C ２ , SC ２ , SOCl ２ , S ２ B ２ , SOBr ２ and combinations thereof.

6. 1.50 MU, as determined by the method described in the Methods section ＊ Shear sensitivity of more than 2.0 MU g / kWs ＊ 6. The polymer of claim 1 having a shear sensitivity of more than 10 g / kWs.

7. 7. The polymer according to claim 1, having a degree of branching Δδ of less than or equal to 19, preferably Δδ between 5 and 19, or having a value for the quotient Mooney viscosity at 100° C. ML1+4 / degree of branching Δδ between 4.9 and 8.7, or both.

8. and a molecular weight distribution (MWD) of less than or equal to 3.0, preferably from 2.0 to 3.0, said MWD being determined by dividing the weight average molecular weight (Mw) by the molecular average molecular weight (Mn), both of which are determined by the equation: MWD = Mw / Mn The polymer according to any one of claims 1 to 7, as determined by gel chromatography according to

9. The polymer according to any one of claims 1 to 8, wherein the polymer is oil extended, optionally in a weight ratio of polymer to extender oil of from 10:1 to 1:

2.

10. A polymer composition comprising at least 60% by weight, preferably at least 95% by weight, of at least one polybutadiene polymer according to any one of claims 1 to 9, relative to the total weight of the composition being 100%.

11. A rubber compound comprising at least 5 wt. % of the polymer according to any one of claims 1 to 9 and further comprising at least one filler or at least one curative capable of curing said polymer, or a combination of at least one filler and at least one curative.

12. A process for producing the polybutadiene polymer of any one of claims 1 to 8, comprising the steps of: (i) a process for producing a polybutadiene polymer, preferably by a polymerization reaction involving the presence of at least one neodymium-containing polymerization catalyst, said polymer having the following characteristics: a) a branching degree Δδ of 21 or less; b) a Mooney viscosity ML1+4 at 100° C. of at least 25 and less than 90 Mooney units; c) 1.50 MU ＊ Shear sensitivity of less than g / kWs; and (ii) treating the reaction mixture with at least one modifier to increase branching and reduce the value of Δδ or increase the Mooney viscosity or the shear sensitivity or both to provide a polymer according to any one of claims 1 to 11, wherein the modifier is selected from the group consisting of sulfur-containing modifiers, polysulfur-containing modifiers or combinations thereof; and optionally (iii) isolating the polybutadiene polymer; The process includes:

13. The modifier is selected from the group consisting of sulfur-containing modifiers and polysulfur-containing modifiers and combinations thereof, and is preferably selected from one or more sulfur halides having 1 to 8 sulfur atoms / molecule, preferably 1 or 2 sulfur atoms / molecule, and ２ C ２ , SC ２ , SOCl ２ , S ２ B ２ , SOBr ２ and combinations thereof.

14. 10. An article comprising the polybutadiene polymer of any one of claims 1 to 9 in cured form, preferably selected from a golf ball, a shoe sole, a hose, a belt, a tire or tire tread, or another component of a tire.

15. 10. A method of manufacturing an article comprising subjecting a composition comprising at least one polybutadiene polymer according to any one of claims 1 to 9 and at least one curing agent for curing said polybutadiene polymer to curing and shaping, said shaping may be performed during, before or after said curing.

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