EP4077406A1 - Process for producing branched polydiene - Google Patents

Process for producing branched polydiene

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Publication number
EP4077406A1
EP4077406A1 EP19956615.9A EP19956615A EP4077406A1 EP 4077406 A1 EP4077406 A1 EP 4077406A1 EP 19956615 A EP19956615 A EP 19956615A EP 4077406 A1 EP4077406 A1 EP 4077406A1
Authority
EP
European Patent Office
Prior art keywords
solvent
process according
neodymium
branching agent
lanthanide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19956615.9A
Other languages
German (de)
French (fr)
Other versions
EP4077406A4 (en
Inventor
Georgy Victorovich DZHABAROV
Aleksei Vladimirovich TKACHEV
Tatiana Aleksandrovna IARTSEVA
Svetlana Alekseevna LAGUNOVA
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Sibur Holding PJSC
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Sibur Holding PJSC
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Publication date
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Publication of EP4077406A1 publication Critical patent/EP4077406A1/en
Publication of EP4077406A4 publication Critical patent/EP4077406A4/en
Pending legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08C—TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
    • C08C19/00—Chemical modification of rubber
    • C08C19/04—Oxidation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F136/00—Homopolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
    • C08F136/02—Homopolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
    • C08F136/04—Homopolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
    • C08F136/06—Butadiene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/04—Polymerisation in solution
    • C08F2/06—Organic solvent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F4/00—Polymerisation catalysts
    • C08F4/42—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors
    • C08F4/44—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides
    • C08F4/54—Metals; Metal hydrides; Metallo-organic compounds; Use thereof as catalyst precursors selected from light metals, zinc, cadmium, mercury, copper, silver, gold, boron, gallium, indium, thallium, rare earths or actinides together with other compounds thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons

Definitions

  • the invention relates to the production of synthetic rubbers used in the manufacture of tires and tire parts, rubber products, golf balls, etc.
  • the invention relates to rubber compositions comprising the obtained branched polydienes, which are used, in particular, in
  • aromatic hydrocarbons or mixtures thereof with aliphatic hydrocarbons are used as solvents for the polymerization of butadiene.
  • the industry mainly uses benzene, toluene, or mixtures thereof with cyclohexane or hexane (Bashkatov T.V., Zhigalin Y.L. Synthetic rubber technology: Textbook for technical schools (in Russian ), 2nd ed., Revised. L .: Chemistry, 1987. 360 p., p. 170, [1]).
  • the use of a mixture of aromatic and aliphatic solvents helps to reduce the viscosity of the polymerizate in comparison with the viscosity of the polymerizate obtained under the same conditions only in an aromatic solvent.
  • Preparing ethylene-alpha-olefin copolymer by solution polymerization method A (CN103880999, UNIV ZHEJIANG, 06/15/2016, [3]) is known.
  • a mixed organic solvent is used for polymerization, which reduces the viscosity of the polymer system, thereby facilitating the separation and purification of the solvent, and, therefore, the known process is characterized by reduced energy consumption.
  • a complex additive is used to reduce the viscosity of the polymer solution.
  • This complex additive consisting of a higher carboxylic acid, alcohol (C1 -C10 alcohols), ammonium / alkali or alkaline earth metal salts (carboxylates, sulfates, sulfonates or phosphates), as well as in some cases water.
  • This additive is introduced into the polymer solution after the polymerization reaction in an amount of 0.7-6.0 wt.% based on the total weight of the polymer.
  • the interaction time of the additive with the polymer solution is 0.5-30 minutes at 100-110°C.
  • the use of this additive results in a decrease in the viscosity of the polymer solution by 31-85%, depending on the composition of the additive and the type of rubber obtained.
  • the polymerization is carried out in the presence of a catalyst system comprising neodymium versatate (neodecanoate) or neodymium tris (bis (2-ethylhexyl) phosphate and dibutyl magnesium).
  • a catalyst system comprising neodymium versatate (neodecanoate) or neodymium tris (bis (2-ethylhexyl) phosphate and dibutyl magnesium).
  • the inventors [5] noted that the use of diethylzinc as an additive can prevent gel formation and significantly reduce the viscosity of the polymerizate.
  • the yield of polydiene does not exceed 72%.
  • the technical problem which is solved by the present invention is to increase productivity, lower the viscosity of the polymer solution and reduce energy consumption when producing polydiene rubbers.
  • the technical result of the invention is the increased productivity of the polydiene production process, decrease of the dynamic viscosity of the polymer solution and the consumption rates of the branching agent, improved processability, increased rubber branching index (characterized by a decrease in the mechanical loss tangent tg ⁇ (1200%)), as well as a decrease in cold flow and an improvement in plasto-elastic properties.
  • various chlorine-containing compounds are used as branching agents, such as tin tetrachloride, methyltin trichloride, dimethyltin dichloride, ethyl tin trichloride, diethyl tin dichloride, n-butyl tin trichloride, di-n-butyl tin chloride, phenyltin trichloride, tri-tetrachloride, diphenyltrichloride, diphenyltrichloride, diphenyltrichloride, diphenyltrichloride, diphenyltrichloride 2,4,6-tri (phenoxy) -1,3,5-triase-2,4,6- triphosphorine, hexachlorocyclotriphosphazene, or mixtures thereof.
  • branching agents such as tin tetrachloride, methyltin trichloride, dimethyltin dichloride, ethyl tin t
  • Tin tetrachloride silicon tetrachloride or hexachlorocyclotriphosphazene are preferably used. Tin tetrachloride is most preferred.
  • the branching agent is used as a 1-20 wt.% solution in an aliphatic solvent.
  • a solution of a branching agent is prepared in advance or immediately before use.
  • the molar ratio of chlorine-containing branching agent BA to lanthanide used according to the invention is from 0.1:1 to 4:1. This ratio provides the production of polydiene with optimal plasto-elastic properties, the mechanical loss tangent tg ⁇ (1200%) is of not more than 6.5, and a high content of 1,4-cis units is of not less than 97 wt.%.
  • the preferred molar ratio of chlorine-containing BA: lanthanide is from 0.2: 1 to
  • the most preferred molar ratio of chlorine-containing BA: lanthanide is from 1 :
  • compounds containing at least two maleic fragments are used as a branching agent.
  • One maleic fragment gives a lower degree of branching, and therefore, it was noted that the processability of rubber compositions is worse in comparison with a polymer modified with two or more maleic fragments.
  • maleinized polydienes are widely distributed and commercially available, in particular maleinized polybutadiene and maleinized polyisoprene rubbers, in one embodiment, maleinized polybutadiene and maleinized polyisoprene low molecular weight rubbers.
  • the molar ratio of the branching agent used according to the invention, containing at least two maleic fragments, to neodymium is from 0.1:1 to 5:1. Said ratio allows to obtain polydiene with optimal plasto-elastic properties, the mechanical loss tangent tg ⁇ (1200%) is not more than 6.5, and a high content of 1,4-cis units is not less than 97 wt.%.
  • the preferred molar ratio maleinized BA: neodymium is from 0.5:1 to 2:1.
  • the molar ratio maleinized BA: neodymium is from 0.8:1 to 1.0:1.
  • the calculated part of the aliphatic solvent (A) is replaced by low-boiling hydrocarbons C5-C6 (B) with boiling points at atmospheric pressure in the range of 25-65°C, preferably 35-60°C, most preferably 40 -50°C.
  • Aliphatic hydrocarbons are used as such hydrocarbons (B), in particular, such as pentane, isopentane, hexane, 2-methylpentane (isohexane), 3 -methylpentane, 2,2-dimethylbutane (neohexane), 2,3 -dimethylbutane, individually or in mixtures with each other, and / or alicyclic hydrocarbons selected from the group consisting of cyclopentane, methylcyclobutane, ethylcyclopropane.
  • isopentane, cyclopentane, hexane are used as low boiling hydrocarbons (B), most preferably cyclopentane, hexane, or mixtures thereof.
  • the proportion of low boiling hydrocarbons (B) is from 7 wt.% to 50 wt.% based on the total weight of the solvent, preferably from
  • Aliphatic solvent (A) for polymerization is an inert organic solvent, which is selected, for example, from heptane, nefras, as well as cycloaliphatic solvents, in particular, such as cyclohexane, cycloheptane or mixtures thereof.
  • nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with a boiling point of 65-75°C.
  • cyclohexane or a mixture of cyclohexane and nefras is used as an aliphatic solvent.
  • a mixture of cyclohexane and nefras is used as an aliphatic solvent in a weight ratio of 65:35 to 70:30, respectively.
  • the authors of the present invention have found that due to the lower viscosity of the low boiling hydrocarbons C5-C6 compared with the viscosity of other aliphatic solvents, the use of low boiling hydrocarbons as an additive reduces the final viscosity of the polydiene solution by 16-51%, which, in turn, increases the monomer content in reaction mixture and, thus, increases the productivity of the polymer production process.
  • the most preferred component weight ratio in a mixed solvent - an aliphatic solvent (A) and lower low boiling hydrocarbons (B) is 90:10.
  • the method for producing diene copolymers in accordance with the present invention includes several steps, in particular: preparing a catalyst system, polymerizing a diene using the above system, introducing a branching agent after not less than 96% conversion of the diene, modifying, termination, performing degassing, isolation and drying the polymer.
  • a catalyst system used comprises a lanthanide compound, an organoaluminum compound, and a halogen-containing component.
  • lanthanide compounds compounds that include at least one lanthanide atom selected from neodymium, lanthanum, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium are used.
  • Neodymium compounds are preferably used.
  • Compounds containing lanthanides include, but are not limited to, compounds such as carboxylates, organophosphates (in particular alkyl phosphates and aryl phosphates), organophosphonates (in particular alkyl phosphonates and aryl phosphonates), organophosphinates (in particular alkyl phosphinates and aryl phosphinates), carbamates, dithiocarbamates, lanthanide dithiocarbonate, ⁇ -diketonates, halides, oxyhalides, and alcoholates.
  • organophosphates in particular alkyl phosphates and aryl phosphates
  • organophosphonates in particular alkyl phosphonates and aryl phosphonates
  • organophosphinates in particular alkyl phosphinates and aryl phosphinates
  • Neodymium carboxylates include neodymium formate, neodymium acetate, neodymium acrylate, neodymium methacrylate, neodymium valerate, neodymium gluconate, neodymium citrate, neodymium fumarate, neodymium maleate, neodymium oxalate, neodymium 2-ethylhexanoate, neodymium neodecanoate, neodymium naphthenate, neodymium stearate, neodymium oleate, neodymium benzoate, and neodymium picolinate.
  • Neodymium organophosphates include neodymium dibutyl phosphate, neodymium diphenyl phosphate, neodymium dihexyl phosphate, neodymium diheptyl phosphate, neodymium dioctyl phosphate, bis-( 1 -methylheptyl) neodymium phosphate, bis-(2-ethylhexyl) neodymium phosphate, neodymium didecyl phosphate, neodymium didodecyl phosphate, neodymium dioctadecyl phosphate, bis-(n-nonylphenyl) neodymium phosphate, butyl (2-ethylhexyl) neodymium phosphate, (1- methylphenyl)(2-ethylhexyl) neodymium phosphate
  • Neodymium organophosphonates include neodymium butylphosphonate, neodymium pentylphosphonate, neodymium hexylphosphonate, neodymium heptylphosphonate, neodymium octylphosphonate, (1 -methylheptyl) neodymium phosphonate, (2-ethylhexyl) neodymium phosphonate, neodymium decyl phosphonate, neodymium dodecyl phosphonate, neodymium octadecyl phosphonate, neodymium oleyl phosphonate, neodymium phenyl phosphonate, (n-nonylphenyl) neodymium phosphonate, butyl (butylphosphonate) neodymium, pentyl (penty
  • Neodymium organophosphinates include neodymium butylphosphinate, neodymium pentylphosphinate, neodymium hexylphosphinate, neodymium heptylphosphinate, neodymium octylphosphinate, (1-methylheptyl) neodymium phosphinate, (2-ethylhexyl) neodymium phosphinate, neodymium decyl phosphinate, neodymium dodecyl phosphinate, neodymium octadecyl phosphinate, neodymium oleyl phosphinate, neodymium phenyl phosphinate, (n-nonylphenyl) neodymium phosphinate, neodymium dibutylphosphin
  • neodymium neodecanoate tris-[bis- (2-ethylhexyl) phosphate] neodymium, or mixtures thereof is most preferred.
  • the organoaluminum compound the following compounds can be used: trialkylaluminum, triphenylaluminum or dialkylaluminum hydrides, alkylaluminum hydrides, in particular, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tritretbutilaluminum, triphenylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, diethylaluminum hydride, di-n- propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, diisohexylaluminum hydride, dioctylaluminum hydride,
  • aluminum alkyls or alkyl aluminum hydrides or mixtures thereof is preferred. Most preferably, triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride or mixtures thereof are used.
  • 1 ,3 -butadiene and isoprene are used as conjugated dienes.
  • organohalogen aluminum compounds can be used, in particular, such as dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide, diethylaluminum bromide, diisobutylaluminum bromide, dimetylaluminum fluoride, diethylaluminum fluoride, diisobutylaluminum fluoride, dimethylaluminum iodide, diethylaluminum iodide, diizobuthylaluminum iodide, methylaluminum dichloride, ethylaluminum dichloride, methylaluminum dibromide, ethylaluminum dibromide, methylaluminum difluoride, ethylaluminum difluoride, methylaluminum sesquichloride, ethylaluminum ses
  • ethyl aluminum sesquichloride is used as the halogen-containing component.
  • a catalyst system comprising (i) a lanthanide compound, (ii) a conjugated diene, (iii) an organoaluminum compound, and (iv) a halogen-containing component which is taken in a molar ratio of (i) :(ii): (iii) :(iv) equal to 1: (5-30) :(8-30) :(1.5-4.5) is used.
  • the preferred molar ratio of the components of the catalyst system (i) :(ii) :(iii) :(iv) 1 : (5-20) :(8-20) :(1.8-4.0).
  • the most preferred molar ratio of the components of the catalyst system (i) :(ii) :(iii) :(iv) 1: (10-15) :(10-15) :(2.1-3.5).
  • the above catalyst system is used to produce branched polydiene by polymerization of a conjugated diene in a mixed hydrocarbon solvent medium.
  • a mixed solvent for polymerization is prepared by mixing predetermined amounts of an aliphatic solvent and low boiling hydrocarbons at room temperature under nitrogen atmosphere, or in the air followed by bubbling nitrogen through the resulting solvent for at least 30 minutes. It is possible to use a mixed solvent both at the stage of polymerization and at the stage of preparation of the catalyst system.
  • a diene copolymer is prepared in a batch or continuous manner in a hydrocarbon solvent medium by feeding a prepared solvent to a polymerization vessel (reactor or autoclave) wherein the solvent comprises a low boiling hydrocarbon monomer, and a catalyst system preliminarily mixed with a solvent consisting of a lanthanide compound, a conjugated diene, anorganoaluminum compound and a halogen-containing organic component.
  • the concentration of monomer in the solvent is 7-15 wt.%, the preferred concentration is 11-13 wt.%.
  • a concentration below 7 wt.% leads to a decrease in the energy efficiency of the process
  • a concentration above 13 wt.% leads to an increase in the viscosity of the polymerizate, and, as a result, in an increase in energy consumption during the isolation and drying of the rubber.
  • the catalyst system is prepared by introducing into a solution of conjugated diene (most preferably 1,3 -butadiene) in an aliphatic solvent (most preferably in a mixture of nefras/cyclohexane or in a mixture of cyclohexane/n-hexane) an organoaluminum compound (most preferably triisobutylaluminium, triethylaluminium, diisobutylaluminium hydride or a mixture thereof), a lanthanide compound (most preferably carboxylate, in particular, neodecanoate of neodymium), maintaining the resulting mixture for 2 to 20 hours at a temperature of 23 ⁇ 2°C, followed by the addition of a halogen-containing component (most preferably ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum chloride, or their mixtures), at the following molar ratio of the components
  • the duration of polymerization is from 0.5 to 3 hours.
  • the conversion of the monomer reaches 96-99%.
  • a branching agent is introduced into the polymer. Further, the resulting mixture is thoroughly mixed for from 15 minutes to 6 hours at a temperature of 60-90°C.
  • the mixing time, and consequently the modification time is preferably from 15 minutes to 5 hours, most preferably from 20 minutes to 2 hours.
  • the viscosity of the polymer will increase, which is undesirable, because of difficulties in the isolation of the polymer and processing thereof.
  • the end groups of the polymer chain tend to lose their activity at temperatures above 90°C, resulting in a decrease in the degree of modification of the polymer.
  • the polymerizate is terminated with softened water, or ethyl or isopropyl alcohol, stabilized with an antioxidant solution taken in an amount of 0.2-0.6 wt.%.
  • the isolation of rubber is carried out by known methods, such as water-steam degassing and drying on rollers.
  • the branched polydiene obtained by the method described above has a Mooney viscosity index of from 39 to 52 Mooney conventional units after modification, the polydispersity index of the obtained diene copolymers corresponds to the range from 2,4 to 2,8, the content of 1 ,4-cis-units is more than 97 wt. %, mechanical loss tangent tg ⁇ (1200%) is in the range from 6.41 to 2.87, plasticity is from 0.41 to 0.56, cold flow is from 17.4 to 35.8 mm /h, elastic recovery is from 0.99 to 2.17 mm.
  • the present invention also relates to rubber compositions based on polydienes obtained by this method, and such compositions being used for the manufacture of tires and rubber products.
  • the mixture of the components of the rubber compositions is determined by the purpose, operating conditions and technical requirements for the product, production technology and other aspects.
  • the process of rubber production includes mixing a rubber with ingredients in special mixers or on mill, cutting and tailoring semi-finished products from rubber (shapes and sizes depend on the planned further use of the obtained rubber, in particular, on the planned test method) and vulcanization of the obtained semi-finished products in special devices (presses, autoclaves, shaper-vulcanizers, etc.).
  • Rubber compositions are based on the obtained polydienes which are prepared according to standard recipes (for example, according to ASTM 3189).
  • the conversion rate is determined by precipitation of the polymer from the polymerizate with ethyl alcohol and drying of the isolated polymer.
  • microstructure of polymer chains was determined by IR spectroscopy according to ISO 12965 using the detachable device of multiple attenuated total internal reflection (MATIR) with a diamond crystal or using the prefix of single attenuated total internal reflection (ATIR) with ZnSe crystal, registration of the IR spectrum of the sample in the range from 4000 to 400 cm -1 with a resolution of 2 cm -1 , the number of scans 32.
  • MATIR multiple attenuated total internal reflection
  • ATIR single attenuated total internal reflection
  • the solvent is tetrahydrofuran, the flow rate 1 cm 3 /min.; - the temperature of the thermostat columns and Refractometer is 30°C.
  • the viscosity of the polymerizate solution was determined using the Brookfield DV2T viscometer according to GOST 25271-93.
  • the Mooney viscosity index was determined by ASTM D 1646.
  • a mixture of diethylaluminum chloride and tributylaluminum is prepared by mixing 1 molar solution of diethylaluminum chloride in hexane (80 ml, 0.08 mol) with 25 wt. % solution of tributylamine in heptane (15,87 g, 0.02 mol) under nitrogen atmosphere.
  • BD diisobutylaluminium hydride
  • DIB AH diisobutylaluminium hydride
  • EASC ethylaluminium sesquichloride
  • DIB AH solution with a concentration of 1.07 mol/1 is fed and the mixture is stirred for 30 minutes.
  • the molar ratio of DIBAH/Nd is equal to 13.
  • a solvent is introduced into the system to a volume of 100 ml solution, stirred for 10 minutes and left to form at 20-23 °C for 22 hours.
  • Polymerization is carried out in a 5 L reactor equipped with a stirring device and a jacket for heat removal.
  • a solvent (A) was used, which was a mixture of cyclohexane/nefras in a weight ratio of 73 : 27.
  • the monomer content in the reaction mass is 11.5 wt.%.
  • the temperature of the polymerization reaction is 90°C.
  • the duration of the process is 2 hours.
  • a branching agent, tin tetrachloride, in the form of a solution with a concentration of 0.91 mol/1 is then fed into the reactor at the rate of 2.5 mol to 1 mol
  • the modification process is carried out with constant stirring for 30 minutes at a temperature of 75°C, after which an antioxidant is introduced (weight fraction of 0.2- 0.4%).
  • the resulting polymer is degassed and dried on mills, physical and mechanical parameters and molecular weight characteristics are determined (see table No. 1). The properties of the resulting polymer are shown in table 1.
  • the sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
  • BD neodymium neodecanoate - butadiene
  • DIB AH diisobutylaluminium hydride
  • EASC ethylaluminium sesquichloride
  • the reaction was performed in a 150-ml Schlenk vessel.
  • 0.87 g (0.522 mmol) of neodymium neodecanoate salt with a concentration of 8.7% as a solution in hexane is placed into the vessel, further 40 ml of the solvent (A) are fed, and stirred on a magnetic stirrer for 10 minutes at a temperature of 23 °C.
  • 0.28 g of butadiene (BD) is introduced into the vessel as a solution with a concentration of 17.8 wt. %, which corresponds to 5.2 mmol of butadiene.
  • Molar ratio of butadiene/ Nd 10.
  • DIB AH solution with a concentration of 1.07 mol/1 is fed and the mixture is stirred for 30 minutes.
  • the molar ratio of DIB AH/Nd 13.
  • the solvent is then introduced into the system to a solution volume of 100 ml, stirred for 10 minutes and left to form at 20- 23°C for 22 hours.
  • Polymerization is carried out in a 5 L reactor equipped with a stirring device and a jacket for heat removal.
  • a mixed solvent is used, obtained by mixing 1702 g of solvent (A), which is a mixture of cyclohexane/nefras in a weight ratio of 73: 27, with 434 g of solvent (B), which is isopentane, thus the solvent content (B) in the polymerization solvent is 10 wt. %.
  • the monomer content in the reaction mass is 11 wt. %.
  • the temperature of the polymerization reaction is 90°C.
  • the duration of the process is 1 hour.
  • tin tetrachloride as a solution in hexane with a concentration of 0.93 mol/1 with a dosage of 2.5 mol with respect to Nd is fed.
  • the modification process is carried out with constant stirring for 30 minutes at a temperature of 75°C, after which an antioxidant is introduced (weight fraction of 0.2- 0.4%).
  • the resulting polymer is degassed and dried on mills, physical and mechanical parameters and molecular weight characteristics are determined.
  • the content of n-hexane in the total volume of the polymerization solvent is 20 wt.%.
  • GdV 3 gadolinium versatate
  • isoprene is used as a monomer
  • 2,4,6 - trichloro-2,4,6- triphenoxycyclotriphosphazene is used as a branching agent in the form of a solution in nefras with a concentration of 0.5 mol/1.
  • the molar ratio of the branching agent to Gd is equal to 1.5.
  • tin tetrachloride is used, in the form of a solution with a concentration of 0.91 mol/1 with a dosage of 3.0 mol with respect to Nd.
  • the monomer content was 13 wt. %.
  • the molar ratio of tin tetrachloride to Gd is 4.0.
  • maleinated polyisoprene (MPI) with a maleic anhydride content of 10 % and a molecular weight of 30000 g/mol is used.
  • MPI maleinated polyisoprene
  • the molar ratio of maleic groups to neodymium is 0.1.
  • Solvent A ane: ane: ane: ane: xane: ne: Nefras
  • Solvent B Cyclopent ane ane ane ntane ane ane Weight ratio of 90.0:10.
  • Solvent A ane: ane: ane ane ane ane ane ane ane ane ane
  • Solvent A ane: ane: ane ne: Nefras ane ane
  • Nefras Nefras: Nefras: Nefras: Cycloh Cycloh Isopent Isopenta Cyclop Cyclop exane: exane: ane ne entane entane hexane hexane

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  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)

Abstract

The invention relates to the production of synthetic rubbers used in the manufacture of tires and tire parts, rubber products, golf balls and other similar products. In particular, the present invention relates to a process for producing a branched polydiene by polymerization of a conjugated diene in a hydrocarbon solvent medium, in the presence of a catalyst system comprising a lanthanide compound, an organosilicon compound, a conjugated diene and a halogen-containing component, by introducing a branching agent at the end of polymerization selected from a group of chlorine-containing compounds or compounds containing at least two maleic fragments, moreover, the hydrocarbon solvent is a mixture of aliphatic solvent (A) and low-boiling hydrocarbons C5-C6 (B), taken in the weight ratio (A): (B)=(50-90):(10-50). The technical result of the invention is to increase the productivity of the polydiene production process, reduce the dynamic viscosity of the polymerizate solution, improve the recyclability, increase the branching index of the polymer, characterized by a decrease in the tangent of the angle of mechanical losses tgδ (1200%), reduce the cold flow and improve the elastoplastic properties.

Description

PROCESS FOR PRODUCING BRANCHED POLYDIENE
Field of the Invention
The invention relates to the production of synthetic rubbers used in the manufacture of tires and tire parts, rubber products, golf balls, etc. In particular, the present invention relates to a process for producing branched polydiene by polymerization of a conjugated diene in a hydrocarbon solvent in the presence of a catalyst system comprising a lanthanide compound, an organoaluminum compound, a conjugated diene and a halogen-containing component, and introducing a branching agent at the end of the polymerization, the agent being selected from the group consisting of chlorine-containing compounds or compounds comprising at least two maleic fragments, wherein the hydrocarbon solvent used in the step of polymerization of diene is a mixture of an aliphatic solvent (A) and low boiling hydrocarbons C5-C6 (B), taken in the weight percentage ratio (A): (B) = (50-90) :(10-50). Moreover, the invention relates to rubber compositions comprising the obtained branched polydienes, which are used, in particular, in the manufacture of tires and rubber products.
Background
Typically, aromatic hydrocarbons or mixtures thereof with aliphatic hydrocarbons are used as solvents for the polymerization of butadiene. The industry mainly uses benzene, toluene, or mixtures thereof with cyclohexane or hexane (Bashkatov T.V., Zhigalin Y.L. Synthetic rubber technology: Textbook for technical schools (in Russian ), 2nd ed., Revised. L .: Chemistry, 1987. 360 p., p. 170, [1]).
It is also known that to ensure high rates of polymerization of butadiene under the action of iodine-containing titanium catalyst system, as well as the production of polybutadiene with the necessary microstructure and molecular parameters, the process has to be carried out in an aromatic solvent or its mixture with a small amount of aliphatic hydrocarbon (Murachev V.B., Aksenov V.I., et al. The impact of the composition of a mixed solvent (toluene-hexane) on the viscosity of polybutadiene and activity of a titanium catalyst system (in Russian)! Ί M.: T sNIITEneftekhim, rukop. Dep. - 12p.- 1987.-87RZHH 10S470, [2]). An increase in the proportion of the aliphatic component leads to a decrease in polymer yield and deterioration of many other properties of the final product.
At the same time, the use of a mixture of aromatic and aliphatic solvents helps to reduce the viscosity of the polymerizate in comparison with the viscosity of the polymerizate obtained under the same conditions only in an aromatic solvent.
Preparing ethylene-alpha-olefin copolymer by solution polymerization method A (CN103880999, UNIV ZHEJIANG, 06/15/2016, [3]) is known. According to the known process, a mixed organic solvent is used for polymerization, which reduces the viscosity of the polymer system, thereby facilitating the separation and purification of the solvent, and, therefore, the known process is characterized by reduced energy consumption.
In the patent RU2523799 (CHINA PETROLEUM & CHEMICAL CORP. INC. (CN), BEIJING UNIVERSITY OF CHEMICAL TECHNOLOGY (CN), 07.27.2014, [4]) a complex additive is used to reduce the viscosity of the polymer solution. This complex additive consisting of a higher carboxylic acid, alcohol (C1 -C10 alcohols), ammonium / alkali or alkaline earth metal salts (carboxylates, sulfates, sulfonates or phosphates), as well as in some cases water. This additive is introduced into the polymer solution after the polymerization reaction in an amount of 0.7-6.0 wt.% based on the total weight of the polymer.
The interaction time of the additive with the polymer solution is 0.5-30 minutes at 100-110°C. The use of this additive results in a decrease in the viscosity of the polymer solution by 31-85%, depending on the composition of the additive and the type of rubber obtained.
However, multicomponent nature of the additive leads to a complication of the hardware design of the process.
In the process described in patent US6177603B1 (BRIDGESTONE CORP (US), January 23, 2001, [5]), the viscosity of the polymerizate is reduced by introducing diethylzinc in the molar ratio Zn / Nd = 3.8-20 into the reaction mass at the stage of polymerization. The polymerization is carried out in the presence of a catalyst system comprising neodymium versatate (neodecanoate) or neodymium tris (bis (2-ethylhexyl) phosphate and dibutyl magnesium). The inventors [5] noted that the use of diethylzinc as an additive can prevent gel formation and significantly reduce the viscosity of the polymerizate. However, when using diethylzinc in a molar ratio of Zn / Nd = 3.8-20, the yield of polydiene does not exceed 72%.
From patents RU2510402 (LANXESS AG (DE), 03/27/2014, [6]) and RU2622648 (SAUDI ARABIAN OIL COMPANY (SAUDI ARAMCO), 06/19/2017, [7]) a method for polymerization in a mixed aliphatic hydrocarbon solvent containing components with a boiling point below 45 °C at a pressure equal to 1013 hPa, as well as components with a boiling point in the range from 45°C to 80°C, at a pressure equal to 1013 hPa, in particular, isopentane and cyclopentane is known. According to the data presented, the viscosity of the polymerizate of the butyl rubber solution is thus reduced, and in addition, the use of these additives can increase the content of solids in the solution to 16-18 wt.%.
In all of the existing methods aromatic solvents are present in the reaction mass, said solvents when polymerized on lanthanide catalyst systems occupy vacant coordination sites in the complex, thereby inhibiting polymerization. Moreover, in these patents nothing is mentioned about any changes / improvements in the properties of the polymer itself in connection with the use of viscosity-reducing additives.
The closest prior art in technical essence and the achieved result is a method for producing rubber, disclosed in patent US5397851 (LANXESS INC. (CA), 03/14/1995, [8]), selected as a prototype of the present invention. According to the data presented in [8], butadiene is polymerized on a catalyst system comprising cobalt dioctate, tributylaluminum and diethylaluminium chloride in a mixed hydrocarbon solvent medium including hexane, butene- 1 and / or benzene. The obtained samples are characterized by a high content of 1,4-cis units (at least 97.4wt.%).
However, in this document of the prior art there is no indication of the influence of the composition of the solvent on the viscosity of the polymer solution and the properties of the resulting rubbers.
SUMMARY OF THE INVENTION
The technical problem which is solved by the present invention is to increase productivity, lower the viscosity of the polymer solution and reduce energy consumption when producing polydiene rubbers.
The technical result of the invention is the increased productivity of the polydiene production process, decrease of the dynamic viscosity of the polymer solution and the consumption rates of the branching agent, improved processability, increased rubber branching index (characterized by a decrease in the mechanical loss tangent tgδ (1200%)), as well as a decrease in cold flow and an improvement in plasto-elastic properties.
Said technical result is achieved by performing the process of polymerization of a conjugated diene in a hydrocarbon solvent in the presence of a catalyst system comprising a lanthanide compound, an organoaluminum compound, a conjugated diene and a halogen-containing component, by introducing a branching agent at the end of the polymerization, selected from the group of chlorine-containing compounds or compounds containing at least two maleic fragments, wherein the hydrocarbon solvent is a mixture of aliphatic solvent (A) and low boiling hydrocarbons C5-C6 (B), taken in the weight ratio (A): (B) = (50-90) :( 10-50).
Detailed Description
The present invention relates to a process of producing a branched polydiene by polymerization of a conjugated diene in a hydrocarbon solvent in the presence of a catalyst system comprising a lanthanide compound, an organoaluminum compound, a conjugated diene and a halogen-containing component, by introducing at the end of the polymerization a branching agent selected from the group of chlorine-containing compounds or compounds containing at least two maleic fragments, wherein the hydrocarbon solvent is a mixture of an aliphatic solvent (A) and low-boiling hydrocarbons C5-C6 (B) in a weight ratio (A): (B) = (50-90) :( 10-50).
To improve the technological properties of rubbers based on the obtained polymers, various branching agents (BA) are used, due to which the formation of branched polymer molecules obtains. This factor influences on such characteristics as the ordering of stacking of chain fragments relative to each other, plasto-elastic properties, melt viscosity, etc., which makes it possible to obtain new materials with improved properties.
In the present invention, various chlorine-containing compounds are used as branching agents, such as tin tetrachloride, methyltin trichloride, dimethyltin dichloride, ethyl tin trichloride, diethyl tin dichloride, n-butyl tin trichloride, di-n-butyl tin chloride, phenyltin trichloride, tri-tetrachloride, diphenyltrichloride, diphenyltrichloride, diphenyltrichloride, diphenyltrichloride 2,4,6-tri (phenoxy) -1,3,5-triase-2,4,6- triphosphorine, hexachlorocyclotriphosphazene, or mixtures thereof.
Tin tetrachloride, silicon tetrachloride or hexachlorocyclotriphosphazene are preferably used. Tin tetrachloride is most preferred.
The branching agent is used as a 1-20 wt.% solution in an aliphatic solvent. A solution of a branching agent is prepared in advance or immediately before use.
The molar ratio of chlorine-containing branching agent BA to lanthanide used according to the invention is from 0.1:1 to 4:1. This ratio provides the production of polydiene with optimal plasto-elastic properties, the mechanical loss tangent tgδ (1200%) is of not more than 6.5, and a high content of 1,4-cis units is of not less than 97 wt.%.
The preferred molar ratio of chlorine-containing BA: lanthanide is from 0.2: 1 to
3: 1.
The most preferred molar ratio of chlorine-containing BA: lanthanide is from 1 :
1 to 2.5: 1.
In another embodiment of the present invention, compounds containing at least two maleic fragments are used as a branching agent. One maleic fragment gives a lower degree of branching, and therefore, it was noted that the processability of rubber compositions is worse in comparison with a polymer modified with two or more maleic fragments. As a compound containing maleic fragments, maleinized polydienes are widely distributed and commercially available, in particular maleinized polybutadiene and maleinized polyisoprene rubbers, in one embodiment, maleinized polybutadiene and maleinized polyisoprene low molecular weight rubbers.
The molar ratio of the branching agent used according to the invention, containing at least two maleic fragments, to neodymium is from 0.1:1 to 5:1. Said ratio allows to obtain polydiene with optimal plasto-elastic properties, the mechanical loss tangent tgδ (1200%) is not more than 6.5, and a high content of 1,4-cis units is not less than 97 wt.%.
The preferred molar ratio maleinized BA: neodymium is from 0.5:1 to 2:1.
Most preferably the molar ratio maleinized BA: neodymium is from 0.8:1 to 1.0:1.
Increasing the molar dosages of the branching agent above the presented range leads to a sharp gap in the Mooney viscosity, which negatively affects the plasto-elastic properties, while there are problems with the selection of the polymer and its processing. Lowering the molar dosages of the branching agent below the indicated ranges is not effective.
According to the claimed method for the polymerization of a conjugated diene, the calculated part of the aliphatic solvent (A) is replaced by low-boiling hydrocarbons C5-C6 (B) with boiling points at atmospheric pressure in the range of 25-65°C, preferably 35-60°C, most preferably 40 -50°C. Aliphatic hydrocarbons are used as such hydrocarbons (B), in particular, such as pentane, isopentane, hexane, 2-methylpentane (isohexane), 3 -methylpentane, 2,2-dimethylbutane (neohexane), 2,3 -dimethylbutane, individually or in mixtures with each other, and / or alicyclic hydrocarbons selected from the group consisting of cyclopentane, methylcyclobutane, ethylcyclopropane.
Preferably, isopentane, cyclopentane, hexane are used as low boiling hydrocarbons (B), most preferably cyclopentane, hexane, or mixtures thereof.
The authors of the present invention have found that the use of hydrocarbons with a boiling point below 25°C is undesirable, since a higher pressure will have to be used to maintain the system in a liquid state. The use of hydrocarbons with a boiling point above 65°C will lead to a decrease in the manufacturability of rubber separation at the degassing stage.
According to the present invention, the proportion of low boiling hydrocarbons (B) is from 7 wt.% to 50 wt.% based on the total weight of the solvent, preferably from
9 wt.% to 20 wt.%, most preferably from 10 wt.% to 15 wt.%. The authors of the present invention found that when the content of low-boiling hydrocarbons is less than 7 wt.% decrease in the viscosity of the polymer solution will be too slight and the presence of low-boiling C5-C6 hydrocarbons will not affect the properties of the final rubber. The content of low-boiling hydrocarbons C5-C6 above 50 wt. % in the total solvent volume will lead to a sharp increase in pressure in the reactor, due to the low boiling point of these hydrocarbons, and in addition, will lead to the accelerated formation of high molecular weight polymer deposits on the internal surfaces of the equipment.
Aliphatic solvent (A) for polymerization is an inert organic solvent, which is selected, for example, from heptane, nefras, as well as cycloaliphatic solvents, in particular, such as cyclohexane, cycloheptane or mixtures thereof. In the context of the present invention, nefras is a hexane-heptane fraction of paraffinic hydrocarbons of dearomatized catalytic reforming gasolines with a boiling point of 65-75°C.
Preferably, cyclohexane or a mixture of cyclohexane and nefras is used as an aliphatic solvent.
Most preferably, a mixture of cyclohexane and nefras is used as an aliphatic solvent in a weight ratio of 65:35 to 70:30, respectively.
The authors of the present invention have found that due to the lower viscosity of the low boiling hydrocarbons C5-C6 compared with the viscosity of other aliphatic solvents, the use of low boiling hydrocarbons as an additive reduces the final viscosity of the polydiene solution by 16-51%, which, in turn, increases the monomer content in reaction mixture and, thus, increases the productivity of the polymer production process. Moreover, it was unexpectedly found out that the presence of low-boiling C5- C6 hydrocarbons in the polymerization solvent significantly increases the efficiency of the use of a branching agent (BA), and also reduces the mechanical loss tangent tgδ (1200%) by 3-25%, which indicates that more branched polymers, characterized by good processability and plasto-elastic properties, are produced using less branching agent.
Since the degree of branching of polydiene rubber increases with a decrease in the mechanical loss tangent tgδ (1200%) with an increase in the content of low-boiling hydrocarbons, in order to achieve optimal polymer properties and the best processability of its preparation, the most preferred component weight ratio in a mixed solvent - an aliphatic solvent (A) and lower low boiling hydrocarbons (B) is 90:10.
The method for producing diene copolymers in accordance with the present invention includes several steps, in particular: preparing a catalyst system, polymerizing a diene using the above system, introducing a branching agent after not less than 96% conversion of the diene, modifying, termination, performing degassing, isolation and drying the polymer.
According to the invention, a catalyst system used comprises a lanthanide compound, an organoaluminum compound, and a halogen-containing component. As the lanthanide compounds, compounds that include at least one lanthanide atom selected from neodymium, lanthanum, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium are used. Neodymium compounds are preferably used.
Compounds containing lanthanides include, but are not limited to, compounds such as carboxylates, organophosphates (in particular alkyl phosphates and aryl phosphates), organophosphonates (in particular alkyl phosphonates and aryl phosphonates), organophosphinates (in particular alkyl phosphinates and aryl phosphinates), carbamates, dithiocarbamates, lanthanide dithiocarbonate, β-diketonates, halides, oxyhalides, and alcoholates.
Neodymium carboxylates include neodymium formate, neodymium acetate, neodymium acrylate, neodymium methacrylate, neodymium valerate, neodymium gluconate, neodymium citrate, neodymium fumarate, neodymium maleate, neodymium oxalate, neodymium 2-ethylhexanoate, neodymium neodecanoate, neodymium naphthenate, neodymium stearate, neodymium oleate, neodymium benzoate, and neodymium picolinate.
Neodymium organophosphates include neodymium dibutyl phosphate, neodymium diphenyl phosphate, neodymium dihexyl phosphate, neodymium diheptyl phosphate, neodymium dioctyl phosphate, bis-( 1 -methylheptyl) neodymium phosphate, bis-(2-ethylhexyl) neodymium phosphate, neodymium didecyl phosphate, neodymium didodecyl phosphate, neodymium dioctadecyl phosphate, bis-(n-nonylphenyl) neodymium phosphate, butyl (2-ethylhexyl) neodymium phosphate, (1- methylphenyl)(2-ethylhexyl) neodymium phosphate, and (2-ethylhexyl)(n-nonylphenyl) neodymium phosphate.
Neodymium organophosphonates include neodymium butylphosphonate, neodymium pentylphosphonate, neodymium hexylphosphonate, neodymium heptylphosphonate, neodymium octylphosphonate, (1 -methylheptyl) neodymium phosphonate, (2-ethylhexyl) neodymium phosphonate, neodymium decyl phosphonate, neodymium dodecyl phosphonate, neodymium octadecyl phosphonate, neodymium oleyl phosphonate, neodymium phenyl phosphonate, (n-nonylphenyl) neodymium phosphonate, butyl (butylphosphonate) neodymium, pentyl (pentylphosphonate) neodymium, hexyl (hexylphosphonate) neodymium, heptyl (heptylphosphonate) neodymium, octyl (octylphosphonate) neodymium, ( 1 -methylheptyl)(( 1 -methylheptyl) phosphonate) neodymium, (2-ethylhexyl)((2-ethylhexyl) phosphonate) neodymium, decyl (decylphosphonate) neodymium, dodecyl (dodecylphosphonate) neodymium, octadecyl(octadecylphosphonate) neodymium, oleyl (oleylphosphonate) neodymium, phenyl (phenylphosphonate) neodymium, (n-nonylphenyl)(n-nonylphenyl) phosphonate) neodymium, butyl ((2-ethylhexyl) phosphonate)neodymium, (2- ethylhexyl) (butylphosphonate) neodymium, (1-methylheptyl) ((2-ethylhexyl) phosphonate) neodymium, (2-ethylhexyl)(( 1-methylheptyl) phosphonate) neodymium, (2-ethylhexyl)((n-nonylphenyl) phosphonate) neodymium, and (p-nonylphenyl)((2- ethylhexyl) phosphonate) neodymium.
Neodymium organophosphinates include neodymium butylphosphinate, neodymium pentylphosphinate, neodymium hexylphosphinate, neodymium heptylphosphinate, neodymium octylphosphinate, (1-methylheptyl) neodymium phosphinate, (2-ethylhexyl) neodymium phosphinate, neodymium decyl phosphinate, neodymium dodecyl phosphinate, neodymium octadecyl phosphinate, neodymium oleyl phosphinate, neodymium phenyl phosphinate, (n-nonylphenyl) neodymium phosphinate, neodymium dibutylphosphinate, neodymium dipentylphosphinate, neodymium dihexylphosphinate, neodymium diheptylphosphinate, neodymium dioctylphosphinate, bis-( 1 -methylheptyl)phosphinate neodymium, bis-(2-ethylhexyl) phosphinate neodymium, tris-[bis-(2-ethylhexyl) phosphinate] neodymium, neodymium didecyl phosphinate, neodymium didodecyl phosphinate, neodymium dioctadecyl phosphinate, neodymium dioleyl phosphinate, neodymium diphenyl phosphinate, bis- (n-nonylphenyl) phosphinate neodymium, butyl (2-ethylhexyl) phosphinate neodymium, (1-methylheptyl) (2-ethylhexyl) phosphinate neodymium, and (2- ethylhexyl)(n-nonylphenyl) phosphinate neodymium.
Most preferred is the use of carboxylates of neo acids due to their faster and more complete alkylation, which leads to more active catalyst compounds.
The use of neodymium neodecanoate, tris-[bis- (2-ethylhexyl) phosphate] neodymium, or mixtures thereof is most preferred.
According to the present invention as the organoaluminum compound the following compounds can be used: trialkylaluminum, triphenylaluminum or dialkylaluminum hydrides, alkylaluminum hydrides, in particular, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tritretbutilaluminum, triphenylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, diethylaluminum hydride, di-n- propylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, dihexylaluminum hydride, diisohexylaluminum hydride, dioctylaluminum hydride, diisoaktylaluminum hydride, phenylethylaluminum hydride, phenyl-n-propylaluminum hydride, phenylisopropylaluminum hydride, phenyl-n-butylaluminum hydride, phenylisobutylaluminum hydride, benzylethylaluminum hydride, benzyl-n- butylaluminum hydride, benzylisobutylaluminum hydride, benzylisopropylaluminum hydride and the like.
The use of aluminum alkyls or alkyl aluminum hydrides or mixtures thereof is preferred. Most preferably, triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride or mixtures thereof are used.
As conjugated dienes in the process according to the invention, 1,3 -butadiene, isoprene, 2,3-dimethyl- 1 ,3-butadiene, piperylene, 2 -methyl-3 -ethyl- 1, 3-butadiene, 3- methyl- 1 ,3-pentadiene, 2-methyl-3 -ethyl- 1 ,3 -pentadiene, 3-methyl- 1 ,3-pentadiene, 1,3- hexadiene, 2-methyl- 1, 3 -hexadiene, 1 ,3-heptadiene , 3 -methyl- 1 ,3 -heptadiene, 1,3- octadiene, 3-butyl-l ,3-octadiene, 3, 4-dimethyl- 1,3 -hexadiene, 4,5-diethyl- 1 ,3-octadiene , phenyl- 1,3-butadiene, 2, 3-diethyl- 1,3-butadiene, 2, 3-di-n-propyl- 1,3 -butadiene, and 2- methyl-3 -isopropyl- 1 ,3 -butadiene are used.
Most preferably, 1 ,3 -butadiene and isoprene are used as conjugated dienes.
As the halogen-containing component, organohalogen aluminum compounds can be used, in particular, such as dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, dimethylaluminum bromide, diethylaluminum bromide, diisobutylaluminum bromide, dimetylaluminum fluoride, diethylaluminum fluoride, diisobutylaluminum fluoride, dimethylaluminum iodide, diethylaluminum iodide, diizobuthylaluminum iodide, methylaluminum dichloride, ethylaluminum dichloride, methylaluminum dibromide, ethylaluminum dibromide, methylaluminum difluoride, ethylaluminum difluoride, methylaluminum sesquichloride, ethylaluminum sesquichloride, isobuthylaluminum sesquichloride, or the mixture thereof.
Preferably, ethyl aluminum sesquichloride is used as the halogen-containing component.
In accordance with the present invention, to carry out the polymerization a catalyst system , comprising (i) a lanthanide compound, (ii) a conjugated diene, (iii) an organoaluminum compound, and (iv) a halogen-containing component which is taken in a molar ratio of (i) :(ii): (iii) :(iv) equal to 1: (5-30) :(8-30) :(1.5-4.5) is used.
The preferred molar ratio of the components of the catalyst system (i) :(ii) :(iii) :(iv) = 1 : (5-20) :(8-20) :(1.8-4.0).
The most preferred molar ratio of the components of the catalyst system (i) :(ii) :(iii) :(iv) = 1: (10-15) :(10-15) :(2.1-3.5).
According to one embodiment of the invention, the above catalyst system is used to produce branched polydiene by polymerization of a conjugated diene in a mixed hydrocarbon solvent medium.
According to the present invention, a mixed solvent for polymerization is prepared by mixing predetermined amounts of an aliphatic solvent and low boiling hydrocarbons at room temperature under nitrogen atmosphere, or in the air followed by bubbling nitrogen through the resulting solvent for at least 30 minutes. It is possible to use a mixed solvent both at the stage of polymerization and at the stage of preparation of the catalyst system.
A diene copolymer is prepared in a batch or continuous manner in a hydrocarbon solvent medium by feeding a prepared solvent to a polymerization vessel (reactor or autoclave) wherein the solvent comprises a low boiling hydrocarbon monomer, and a catalyst system preliminarily mixed with a solvent consisting of a lanthanide compound, a conjugated diene, anorganoaluminum compound and a halogen-containing organic component. The concentration of monomer in the solvent, as a rule, is 7-15 wt.%, the preferred concentration is 11-13 wt.%. A concentration below 7 wt.% leads to a decrease in the energy efficiency of the process, a concentration above 13 wt.% leads to an increase in the viscosity of the polymerizate, and, as a result, in an increase in energy consumption during the isolation and drying of the rubber.
The catalyst system is prepared by introducing into a solution of conjugated diene (most preferably 1,3 -butadiene) in an aliphatic solvent (most preferably in a mixture of nefras/cyclohexane or in a mixture of cyclohexane/n-hexane) an organoaluminum compound (most preferably triisobutylaluminium, triethylaluminium, diisobutylaluminium hydride or a mixture thereof), a lanthanide compound (most preferably carboxylate, in particular, neodecanoate of neodymium), maintaining the resulting mixture for 2 to 20 hours at a temperature of 23±2°C, followed by the addition of a halogen-containing component (most preferably ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum chloride, or their mixtures), at the following molar ratio of the components of the catalyst system: (i) a lanthanide compound, (ii) conjugated diene (iii) an organoaluminum compound and (iv) halogen- containing component (i) : (ii) :(iii) : (i v) equal 1 :(5-30):(8-30):(1, 5-3,0).
The duration of polymerization is from 0.5 to 3 hours. The conversion of the monomer reaches 96-99%.
Upon reaching the above conversion, a branching agent is introduced into the polymer. Further, the resulting mixture is thoroughly mixed for from 15 minutes to 6 hours at a temperature of 60-90°C. The mixing time, and consequently the modification time, is preferably from 15 minutes to 5 hours, most preferably from 20 minutes to 2 hours. At temperatures below 60°C, the viscosity of the polymer will increase, which is undesirable, because of difficulties in the isolation of the polymer and processing thereof. At the same time, the end groups of the polymer chain tend to lose their activity at temperatures above 90°C, resulting in a decrease in the degree of modification of the polymer.
At the end of the modification process, the polymerizate is terminated with softened water, or ethyl or isopropyl alcohol, stabilized with an antioxidant solution taken in an amount of 0.2-0.6 wt.%. Further, the isolation of rubber is carried out by known methods, such as water-steam degassing and drying on rollers.
The branched polydiene obtained by the method described above has a Mooney viscosity index of from 39 to 52 Mooney conventional units after modification, the polydispersity index of the obtained diene copolymers corresponds to the range from 2,4 to 2,8, the content of 1 ,4-cis-units is more than 97 wt. %, mechanical loss tangent tgδ (1200%) is in the range from 6.41 to 2.87, plasticity is from 0.41 to 0.56, cold flow is from 17.4 to 35.8 mm /h, elastic recovery is from 0.99 to 2.17 mm.
The present invention also relates to rubber compositions based on polydienes obtained by this method, and such compositions being used for the manufacture of tires and rubber products. The mixture of the components of the rubber compositions is determined by the purpose, operating conditions and technical requirements for the product, production technology and other aspects.
The process of rubber production includes mixing a rubber with ingredients in special mixers or on mill, cutting and tailoring semi-finished products from rubber (shapes and sizes depend on the planned further use of the obtained rubber, in particular, on the planned test method) and vulcanization of the obtained semi-finished products in special devices (presses, autoclaves, shaper-vulcanizers, etc.).
Rubber compositions are based on the obtained polydienes which are prepared according to standard recipes (for example, according to ASTM 3189).
Examples of the invention implementation
Examples of the implementation of the present invention are described below. It should be clarified that the present invention is not limited to the presented examples and the same effect can be achieved in other embodiments that do not go beyond the essence of the claimed invention.
The test methods used to evaluate the properties of polymers obtained by the claimed process are described.
1. The conversion rate is determined by precipitation of the polymer from the polymerizate with ethyl alcohol and drying of the isolated polymer.
2. The microstructure of polymer chains was determined by IR spectroscopy according to ISO 12965 using the detachable device of multiple attenuated total internal reflection (MATIR) with a diamond crystal or using the prefix of single attenuated total internal reflection (ATIR) with ZnSe crystal, registration of the IR spectrum of the sample in the range from 4000 to 400 cm-1 with a resolution of 2 cm-1, the number of scans 32.
3. Molecular weight characteristics of rubbers were determined by gel- permeation chromatography by internal technique using gel-chromatographic system "Breeze" of the "Waters" company with refractometric detector. Samples of rubbers were dissolved in freshly distilled tetrahydrofuran, the weight concentration of the polymer in solution was 2 mg/ ml, the calculation was carried out by universal calibration using polystyrene standards and Mark-Kuhn-Hauwink constants for polybutadiene (K = 0.000457, α = 0.693). The determining conditions:
- Bank of 4 high-resolution columns (300 mm long, 7.8 mm diameter) filled with styrogel, HR3, HR4, HR5, HR6, allowing to analyze polymers with molecular weight from 500 to 1*107 AU;
- the solvent is tetrahydrofuran, the flow rate 1 cm3/min.; - the temperature of the thermostat columns and Refractometer is 30°C.
4. Determination of the mechanical loss tangent (tgδ (1200%)) was carried out on the device RPA-2000 company "Alpha Technologies" at variable shear amplitude: amplitude range from 0 to 1200%, frequency 0.1 Hz, temperature 100°C.
5. The viscosity of the polymerizate solution was determined using the Brookfield DV2T viscometer according to GOST 25271-93.
6. Determination of plastoelastic characteristics of rubbers (plasticity, cold flow) was carried out according to national standards GOST 19920.17 and GOST 19920.18 on a compression-type plastometer with thermostat, model GT7060SA.
7. The Mooney viscosity index was determined by ASTM D 1646.
8. The elastic component of the complex dynamic shear modulus G' (kPa), which allows to estimate the distribution of filler in rubber blends and silanization of the filler, was determined on the RPA-2000 rubber recyclability analyzer of "Alpha Technologies" at 0.1 Hz and 100°C in the deformation range from 1 to 450%. Difference of accumulation modules at deformation amplitude of 1% and 50% - ΔG' =
(G '1% - G’ 43%) - Payne effect.
9. Abrasion resistance when sliding on a renewable surface was evaluated according to GOST 23509 (method B) on the ABRASION CHECK "Gibitre Instruments".
Example 1 (according to the closest prior art)
A mixture of diethylaluminum chloride and tributylaluminum is prepared by mixing 1 molar solution of diethylaluminum chloride in hexane (80 ml, 0.08 mol) with 25 wt. % solution of tributylamine in heptane (15,87 g, 0.02 mol) under nitrogen atmosphere.
In order to conduct polymerization in a glass reactor, which is a bottle of 1 liter, 150.0 g of cyclohexane, 84.0 g of 1 -butene, 0.24 ml (1.22 mmol) of water, 4.0 ml of 1 ,5-octadiene and 72.0 g (1.33 mol) 1,3-butadiene (butadiene content was 23 wt. % of the total weight of the solution) are loaded, and then the mixture is stirred by shaking in a water bath at 20°C for 10 minutes. After that, a mixture of diethylaluminium chloride and tributylaluminium (3.5 mmol) is added to the solution, followed by stirring the resulting solution in a water bath at 20°C for 10 minutes. Then, 0.22 ml (0.0067 mol) 0.87 wt. % of cobalt dioctoate solution in hexane is added. Polymerization is carried out for 30 minutes at 20°C, after which a mixture of water and methanol is added to deactivate the catalyst and precipitate polybutadiene. Next, the polymer is dried in a vacuum oven at 60°C for 24 hours.
The properties of the resulting polymer are presented in table 1.
Example 2 (comparative)
At the first stage, a catalyst system of neodymium neodecanoate - butadiene
(BD) diisobutylaluminium hydride (DIB AH) - ethylaluminium sesquichloride (EASC) with a molar ratio of 1:10:13:2.5 (by substance) is obtained. The maturation (ageing) time of the system is 22 hours at a temperature of 23°C.
In a 150 ml Schlenk vessel, 0.87 g (0.522 mmol) of neodymium neodecanoate salt with a concentration of 8.7% in the form of a solution in hexane, 40 ml of aliphatic solvent is placed and stirred on a magnetic stirrer for 10 minutes at a temperature of 23°C. Then 0.28 g of butadiene (BD) is introduced into the vessel as a solution with a concentration of 17.8 wt. %, which corresponds to 5.2 mmol of butadiene. Molar ratio of butadiene/ Nd= 10.
After 15 minutes of stirring the contents at 23 °C, 6.3 ml of DIB AH solution with a concentration of 1.07 mol/1 is fed and the mixture is stirred for 30 minutes. The molar ratio of DIBAH/Nd is equal to 13. Further, 2.0 ml of EASC solution with a concentration of 0.66 mol/1, molar ratio Cl/Nd=2.5 was fed into the mixture. Then a solvent is introduced into the system to a volume of 100 ml solution, stirred for 10 minutes and left to form at 20-23 °C for 22 hours.
Polymerization is carried out in a 5 L reactor equipped with a stirring device and a jacket for heat removal. As a medium, a solvent (A) was used, which was a mixture of cyclohexane/nefras in a weight ratio of 73 : 27. The monomer content in the reaction mass is 11.5 wt.%. The temperature of the polymerization reaction is 90°C. The duration of the process is 2 hours.
A branching agent, tin tetrachloride, in the form of a solution with a concentration of 0.91 mol/1 is then fed into the reactor at the rate of 2.5 mol to 1 mol
Nd. The modification process is carried out with constant stirring for 30 minutes at a temperature of 75°C, after which an antioxidant is introduced (weight fraction of 0.2- 0.4%). The resulting polymer is degassed and dried on mills, physical and mechanical parameters and molecular weight characteristics are determined (see table No. 1). The properties of the resulting polymer are shown in table 1. The sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
Example 3 (according to the invention)
At the first stage, a catalyst system of neodymium neodecanoate - butadiene (BD) - diisobutylaluminium hydride (DIB AH) - ethylaluminium sesquichloride (EASC) with a molar ratio of 1:10:13:2.5 (by substance) is obtained. The maturation (ageing) time of the complex is 22 hours at a temperature of 23°C.
The reaction was performed in a 150-ml Schlenk vessel. 0.87 g (0.522 mmol) of neodymium neodecanoate salt with a concentration of 8.7% as a solution in hexane is placed into the vessel, further 40 ml of the solvent (A) are fed, and stirred on a magnetic stirrer for 10 minutes at a temperature of 23 °C. Then, 0.28 g of butadiene (BD) is introduced into the vessel as a solution with a concentration of 17.8 wt. %, which corresponds to 5.2 mmol of butadiene. Molar ratio of butadiene/ Nd=10.
After 15 minutes of stirring the mixture at 23°C, 6.3 ml of DIB AH solution with a concentration of 1.07 mol/1 is fed and the mixture is stirred for 30 minutes. The molar ratio of DIB AH/Nd= 13. Further, 2.0 ml of EASC solution with a concentration of 0.66 mol/1, molar ratio Cl/Nd=2.5 is administered. The solvent is then introduced into the system to a solution volume of 100 ml, stirred for 10 minutes and left to form at 20- 23°C for 22 hours.
Polymerization is carried out in a 5 L reactor equipped with a stirring device and a jacket for heat removal. As a medium a mixed solvent is used, obtained by mixing 1702 g of solvent (A), which is a mixture of cyclohexane/nefras in a weight ratio of 73: 27, with 434 g of solvent (B), which is isopentane, thus the solvent content (B) in the polymerization solvent is 10 wt. %. The monomer content in the reaction mass is 11 wt. %. The temperature of the polymerization reaction is 90°C. The duration of the process is 1 hour.
Then into the reactor a branching agent, tin tetrachloride, as a solution in hexane with a concentration of 0.93 mol/1 with a dosage of 2.5 mol with respect to Nd is fed. The modification process is carried out with constant stirring for 30 minutes at a temperature of 75°C, after which an antioxidant is introduced (weight fraction of 0.2- 0.4%). The resulting polymer is degassed and dried on mills, physical and mechanical parameters and molecular weight characteristics are determined.
The properties of the resulting polymer are presented in table 1.
Example 4
Similar to example 3 with the difference that the solvent content (B) in the polymerization solvent is 20 wt.%.
The properties of the resulting polymer are presented in table 1. The sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
Example 5
Similar to example 3 with the difference that isoprene is used as a monomer, its content in the reaction mass is 13.0 wt. % and the molar ratio of SnCl4 to Nd is 0.2.
The properties of the resulting polymer are shown in table 1.
Example 6
Similar to example 5 with the difference that the solvent (B) content in the polymerization solvent is 20 wt. %.
The properties of the resulting polymer are shown in table 1. The sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
Example 7
Similar to example 3 with the difference that as solvent (B) cyclopentane is used.
The properties of the resulting polymer are shown in table 1.
Example 8
Similar to example 7 with the difference that the solvent (B) content in the polymerization solvent is 20 wt. %, and the molar ratio of SnCl4 to Nd is 0.1.
The properties of the resulting polymer are shown in table 1.
Example 9
Similar to example 7 with the difference that the solvent (B) content in the polymerization solvent is 15 wt. %.
The properties of the resulting polymer are shown in table 1.
Example 10
Similar to example 7 with the difference that isoprene is used as a monomer and SnCl4 is used as a branching agent in the form of a solution in hexane with a concentration of 0.83 mol / 1 with a dosage of 2.5 mol to Nd.
The properties of the resulting polymer are shown in table 1. The sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
Example 11
Similar to example 10, with the difference that as a branching agent, 2, 2, 4, 4,6,6- hexachloro- 1 ,3,5-triase-2,4,6-triphosphorine is used as a solution in toluene with a concentration of 0.5 mol/1 with a dosage of 1.5 mol to Nd.
The properties of the resulting polymer are shown in table 1. The sample was also tested according to the formulation of rubber compounds ASTM 3189 (table 2), the test results are presented in table 3.
Example 12
Similar to example 7 with the difference that as a branching agent maleinated polybutadiene (MPB) with a maleic anhydride content of 8% and a molecular weight of 2700 g/mol is used. The molar ratio of maleic groups to neodymium is 0.8.
The properties of the resulting polymer are shown in table 1.
Example 13
Similar to example 10 with the difference that as a compound containing lanthanide, tris-[bis-(2-ethylhexyl)phosphate]neodymium is used, isopentane is chosen as a solvent, the content of low-boiling hydrocarbon in the solvent (B) is 20%, as a branching agent, SnCl4 is used as a solution in hexane with a concentration of 0.9 mol/1 with a mole dosage to Nd 2.0.
The properties of the resulting polymer are shown in table 1. The sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
Example 14
Similar to example 7 with the difference that as a compound containing lanthanide, tris-[bis-(2-ethylhexyl)phosphate]neodymium is used.
The properties of the resulting polymer are shown in table 1.
Example 15
Similar to example 3 with the difference that cyclohexane is used as the solvent (A) and n-hexane is used as the solvent (B), the content of n-hexane in the total volume of the polymerization solvent is 20 wt.%.
The properties of the resulting polymer are presented in table 1. The sample was also tested according to the formulation of rubber compositions ASTM 3189 (table 2), the test results are presented in table 3.
Example 16
Similar to example 15 with the difference that the solvent (B) content in the polymerization solvent is 30 wt. %.
The properties of the resulting polymer are shown in table 1.
Example 17
Similar to example 15 with the difference that the solvent (B) content in the polymerization solvent is 50 wt. % and the content of the monomer is 11.6 wt. %.
The properties of the resulting polymer are shown in table 1.
Example 18
Similar to example 15 with the difference that the solvent (B) content in the polymerization solvent is 50 wt. % and monomer content is 13 wt. %.
The properties of the resulting polymer are shown in table 1.
Example 19
Similar to example 14 with the difference that as a solvent (A) cyclohexane is used, as a solvent (B)- n-hexane, the weight percentage ratio (A): (B) is 80:20. As a branching agent, 2,4,6-trichloro-2,4,6-triphenoxy cyclotriphosphazene is used as a solution in nefras with a concentration of 0.5 mol/1, the dosage to Nd was 1.0 mol.
The properties of the resulting polymer are shown in table 1.
Example 20
Similar to example 3 with the difference that gadolinium versatate (GdV3) is used as a lanthanide compound, isoprene is used as a monomer, 2,4,6 - trichloro-2,4,6- triphenoxycyclotriphosphazene is used as a branching agent in the form of a solution in nefras with a concentration of 0.5 mol/1. The molar ratio of the branching agent to Gd is equal to 1.5.
The properties of the resulting polymer are shown in table 1.
Example 21
Similar to example 19, characterized in that as a branching agent, tin tetrachloride is used, in the form of a solution with a concentration of 0.91 mol/1 with a dosage of 3.0 mol with respect to Nd. The monomer content was 13 wt. %.
The properties of the resulting polymer are shown in table 1.
Example 22
Similar to example 15 with the difference that GdV3 is used as the lanthanide compound, the molar ratio of tin tetrachloride to Gd is 4.0.
The properties of the resulting polymer are shown in table 1.
Example 23
Similar to example 12 with the difference that as a branching agent maleinated polyisoprene (MPI) with a maleic anhydride content of 10 % and a molecular weight of 30000 g/mol is used. The molar ratio of maleic groups to neodymium is 0.1.
The properties of the resulting polymer are shown in table 1.
Example 24
Similar to example 12 with the difference that the molar ratio of maleic groups to neodymium is equal to 5.
The properties of the resulting polymer are shown in table 1.
Rubber samples obtained in examples 4, 6, 13, 10, 11, 15, have been tested in the formulation of rubber compositions ASTM 3189 (see table 2). The test results are shown in table 3.
Table 1
Mode of preparation and properties of copolymers
Example number
Dimensiona 1 2
1 unit (closest (compa 3 4 5 6 prior art) rative)
Lanthanide
NdV3 NdV3 NdV3 NdV3 NdV3 compound
Monomer butadiene butadiene butadiene butadiene isoprene isoprene
Concentrati on of the
23.0 11.0 11.0 11.0 13.0 13.0 monomer in the solution, Wt. %
Cyclohe Cyclohe
Cyclohex Cyclohexa Cyclohexa Cyclohexa
Solvent A xane: xane: ane ne: Nefras ne: Nefras ne: Nefras
Nefras Nefras
Isopentan Isopenta Isopenta
Solvent B Butene- 1 Isopentane e ne ne
Weight ratio of 80.0:20.
64.1:35.9 100.0:0.0 90.0:10.0 80.0:20.0 90.0:10.0 solvents A: 0
B
BA, type,
SnCL4 SnCL4 SnCL4 SnCL4 SnCL4 dosage per
2.5/Nd 2.5/Nd 2.5/Nd 0.2/Nd 2.5/Nd mole
The viscosity of the polymer
4236 3528 2125 6225 3948 solution, MPa*s, at 25°C
Polymer properties
Mooney viscosity
ML 1+4
32.4 47.3 43.7 43.0 42.0 47.3
(100°C),
Mooney unit
The area under the relaxation
230 347 217 203 546 curve A,
Mooney unit*s Plasticity 0.56 0.49 0.51 0.47 0.48
Elastic recovery, 0.99 1.76 1.70 1.71 1.80 mm
Cold flow,
35.8 30.4 31.6 33.7 20.5 mm/h
Mw/Mn 3.7 2.65 2.51 2.8 2.53 2.7
1.4-cis-
97.4 98.4 97.6 98.1 97.7 98.2 units,%
Mechanical loss tangent 6.12 4.00 4.58 5.8 2.99 (tg6 1200%)
Table 1. Continuation
Dimensio Example number nal unit 7 8 9 104 11 12
Lanthanid e NdV3 NdV3 NdV3 NdV3 NdV3 NdV3 compound
Monomer butadiene butadiene butadiene butadiene isoprene butadiene
Concentra tion of the monomer
11.0 11.0 11.0 11.0 11.0 11.0 in the solution wt. %
Cyclohex Cyclohex Cyclohex Cyclohex Cyclohe
Cyclohexa
Solvent A ane: ane: ane: ane: xane: ne: Nefras
Nefras Nefras Nefras Nefras Nefras
Cyclopent Cyclopent Cyclopent Cyclope Cyclopent
Solvent B Cyclopent ane ane ane ntane ane ane Weight ratio of 90.0:10.
90.0:10.0 80.0:20.0 85.0:15.0 90.0:10.0 90.0:10.0 solvents 0
A: B
BA, type,
SnCL4 SnCL4 SnCL4 SnCL4 HCF MPB dosage per
2.5/Nd 0.1/Nd 2.5/Nd 2.5/Nd 1.5/Nd 2.5/Nd mole
The viscosity of the
2161.0 2363.0 2674.0 2453.0 2726.0 polymer 2509.0 solution, MPa*s, at
25°C
Polymer properties
Mooney viscosity
ML 1+4
49.8 44.0 50.4 50.5 51.8 50.3
(100°C),
Mooney unit
The area under the relaxation
310 165 573 216 295 159 curve A,
Mooney unit*s
Plasticity 0.48 0.54 0.43 0.53 0.45 0.58
Elastic recovery, 1.43 1.92 1.99 1.29 1.89 1.16 mm
Cold flow, 32.8 33.5 25.7 34.2 29.5 35.6 mtn/h
Mw/Mn 2.42 2.73 2.45 2.48 2.38 2.35
1.4-cis-
98.1 98.6 97.0 97.7 97.9 97.1 units, %
Mechanic al loss tangent 4.83 6.1 2.87 5.67 4.36 6.41
(tgδ
1200%)
Table 1. Continuation
Dimensio Example number nal unit 13 14 15 16 17 18
Lanthanid e NdV3 NdV3 NdV3 NdV3 NdV3 NdV3 compound
Monomer isoprene butadiene butadiene butadiene butadiene butadiene
Concentra tion of the monomer
11.0 11.0 11.0 11.0 11.0 13.0 in the solution, wt. %
Cyclohex Cyclohex
Cyclohex Cyclohex Cyclohex Cyclohex
Solvent A ane: ane: ane ane ane ane
Nefras Nefras
Isopen Cyclo
Solvent B N-hexan N-hexane N-hexane N-hexane tane pentane
Weight ratio of
80.0:20.0 90.0:10.0 80.0:20/0 70.0:30.0 50.0:50.0 50.0:50.0 solvents
A: B BA, type,
SnCL4 SnCL4 SnCL4 SnCL4 SnCL4 SnCL4 dosage per
2.0/Nd 2.5/Nd 2.5/Nd 2.5/Nd 2.5./Nd 2.5/Nd mole
The viscosity of the polymer 2023.0 2476.0 3400.0 2568.0 2250.0 4056.0 solution, MPa*s, at 25°C
Polymer properties
Mooney viscosity ML 1+4
43.2 45.4 45.8 51.4 48.3 41.6
(100°C),
Mooney unit
The area under the relaxation
271 315 267 417 360 328 curve A,
Mooney unit*s
Plasticity 0.43 0.47 0.49 0.43 0.46 0.53
Elastic recovery, 1.63 1.95 1.57 2.17 1.97 1.29 mm
Cold flow,
35.7 25.4 28.75 17.4 26.25 45.5 mm/h
Mw/Mn 2.40 2.47 2.39 2.51 2.51 2.3
1 ,4-cis-
96.6 96.5 97.7 97.65 97.8 97.1 units, % Mechanic al loss
5.97 4.75 4.91 3.55 3.8 3.28 angle (tgδ
1200%)
Table 1. Continuation
Example number
Dimensio 20 nal unit 19 (comparat 21 22 23 24 ive)
Lanthanid e NdP3 GdV3 NdV3 GdV3 NdV3 NdV3 compound
Monomer butadiene isoprene butadiene butadiene butadiene butadiene
Concentra tion of the monomer
11.0 11.0 13.0 11.0 11.0 11.0 in the solution, wt. %
Cyclohex Cyclohex
Cyclohex Cyclohexa Cyclohex Cyclohex
Solvent A ane: ane: ane ne: Nefras ane ane
Nefras Nefras
Isopen Cyclopent Cyclopent
Solvent B N-hexane N-hexane N-hexane tane ane ane
Weight ratio of
80.0:20.0 90.0:10.0 80.0:20.0 80.0:20.0 90.0:10.0 90.0:10.0 solvents
A: B
BA, type,
THE TGF SnCL4 SnCL4 MPI MPB dosage per
1.0/Nd 1.5/Nd 3.0/Nd 4.0/Nd 0.1/Nd 5/Nd mole The viscosity of the polymer 3580 2476 6114 3123 3641 2918 solution, MPa*s, at
25°C
Polymer properties
Mooney viscosity
ML 1+4
39.7 42.6 44.7 42.1 43.8 47.6
(100°C),
Mooney unit
The area under the relaxation
218 278 371 449 119 250 curve A,
Mooney unit*s
Plasticity 0.41 0.46 0.48 0.47 0.59 0.48
Elastic recovery, 1.69 1.81 1.91 1.89 1.21 1.10 mm
Cold flow,
34.9 28.3 27.3 22.3 34.8 31.2 mm/h
Mw/Mn 2.64 2.75 2.68 2.71 2.59 2.64
1.4-cis-
97.5 96.9 96.1 96.0 96.3 96.6 units,%
Mechanic 4.98 4.31 4.27 3.87 6.97 3.74 al loss tangent
(tgδ
1200%)
List of abbreviations in table 1:
BA-branching agent;
BD-butadiene;
NdP3-Tris-[bis-(2-ethylhexyl)phosphate] neodymium NDV3 -neodymium neodecanoate GdV3 -gadolinium versatate
HCF - 2,2,4,4,6,6-hexachloro-l,3,5-triaza-2,4,6-triphosphorin; THF-2,4,6-trichloro-2,4,6-triphenoxy cyclotriphosphazene; MPB - maleinated polybutadiene MPI - maleinated polyisoprene Table 2
Formulation of rubber compounds (ASTM 3189)
Name of ingredients parts by weight
Butadiene rubber 100.0
60.0
Carbon black N330
White zinc 3.0
Stearic acid
Naphthenic oil 15.0
Gas Sulfur 1.5
Sulfenamide T 0.9
Total: 182.40
Table 3
Characteristics of rubber compounds
Dimensiona Example number
1 unit 2 4 10 11 13 15
Solvent Nefras Nefras: Nefras: Nefras: Nefras: Cycloh Cycloh Isopent Isopenta Cyclop Cyclop exane: exane: ane ne entane entane hexane hexane
90/10 80/20 90/10 90/10 80/20 50/50
Mooney viscosity
ML (1+4), 76.1 62.6 58.8 72.8 73.9 68.5 67.3
Mooney units
The area under the relaxation
498 362 363 473 439 399 429 curve A,
Mooney unit*s
Payne
Effect
Δ (G '1% - 228 227 224 163 176 172 224 G' 50%), kPa
Tear resistance, 39 44 49 43 48 54 45 kN / m
As can be seen from table 1, when using as a solvent a mixture of aliphatic solvent (A) and low-boiling hydrocarbons C5-C6 (B), taken in different percentages, the branching index of polydiene increases, as evidenced by the low value of the mechanical loss tangent tgδ (1200%), the viscosity of the polymer solution and the cold flow decreases. In comparison with the prototype, a significant improvement in polydispersity was noted in all samples obtained according to the proposed invention.
The results of testing of rubber compositions (table 3) based on samples obtained according to the invention, illustrate the improvement of the processability, expressed in a lower Mooney viscosity for rubber compositions, improving the interaction of the filler with the polymer matrix, resulting in the decrease of the Payne effect as well as the improvement (increase) of tear resistance.

Claims

WHAT IS CLAIMED IS:
1. A process for producing a branched polydiene comprising the following steps: preparation of a catalyst system comprising (i) a lanthanide compound, (ii) an organoaluminum compound, (iii) a conjugated diene, and (iv) a halogen-containing component; polymerization of conjugated diene in a hydrocarbon solvent in the presence of said catalyst system; introduction of branching agent; modification, termination, degassing, isolation and drying of the polymer, characterized in that upon reaching at least 96% conversion of conjugated diene, a branching agent is introduced selected from the group of chlorine-containing compounds or compounds containing at least two maleic fragments, wherein the hydrocarbon solvent is a mixture of aliphatic solvent (A) and low-boiling hydrocarbons C5-C6 (B), taken in the weight ratio (A) : (B) = (50-90):(10-50).
2. The process according to claim 1, characterized in that lanthanide compound is selected from the group of neodymium, lanthanum, cerium, praseodymium, promethium, samarium, europium, gadolinium, terbium, dysprosia, holmium, erbium, thulium, ytterbium, and lutetium.
3. The process according to claim 2, characterized in that neodymium is used as the lanthanide compound.
4. The process according to claim 1, characterized in that as a branching agent selected from the group of chlorinated compounds such as tin tetrachloride, methyltin trichloride, dimethyltin dichloride, ethyltin trichloride, diethyltin dichloride, n-butyltin trichloride, di-n-butyltin dichloride, phenyltin trichloride, diphenyltin dichloride, silicon tetrachloride, 2,4,6-trichloro-2,4,6-tri(phenoxy)-1,3,5-triaza-2,4,6- triphosphorin, hexachlorocyclotriphosphazene or mixtures thereof.
5. The process according to claim 4, characterized in that a branching agent is selected from the group of chlorine-containing compounds, preferably from tin tetrachloride, silicon tetrachloride or hexachlorocyclotriphosphazene.
6. The process according to claim 5, characterized in that as a chlorine- containing branching agent tin tetrachloride is the most preferable.
7. The process according to claim 1, characterized in that the chlorine- containing branching agent is used in the form of 1-20 wt.% solution in aliphatic solvent.
8. The process according to claim 1 , characterized in that the molar ratio of the chlorine-containing branching agent to the lanthanide is from 0.1:1 to 4: 1.
9. The process according to claim 8, characterized in that the preferred molar ratio of the chlorine-containing branching agent to the lanthanide is from 0.2:1 to 3: 1.
10. The process according to claim 9, characterized in that the most preferred molar ratio of the chlorine-containing branching agent to the lanthanide is from 1:1 to 2.5:1.
11. The process according to claim 1 , characterized in that as a branching agent containing at least two maleic fragments, maleinized polydienes, in particular, maleinized polybutadiene and maleinized polyisoprene rubbers, are used.
12. The process according to claim 1, characterized in that the molar ratio of the branching agent (BA) containing at least two maleic fragments to the lanthanide is from 0.1:1 to 5: 1.
13. The process according to claim 12, characterized in that the preferred molar ratio of maleinized branching agent: lanthanide is from 0.5:1 to 2: 1.
14. The process according to claim 13, characterized in that the most preferred molar ratio of maleinized branching agent: lanthanide is from 0.8:1 to 1:1.
15. The process according to claim 1, characterized in that low-boiling hydrocarbons (solvent (B)) are selected from aliphatic hydrocarbons such as pentane, isopentane, hexane, 2-methylpentane (isohexane), 3 -methylpentane, 2,2-dimethylbutane (neohexane), 2,3 -dimethylbutane, or alicyclic hydrocarbons, such as particular cyclopentane, methylcyclobutane, ethylcyclopropane, which are used individually or in mixtures with each other.
16. The process according to claim 15, characterized in that as a solvent (B) isopentane, cyclopentane, hexane, or mixtures thereof are used.
17. The process according to claim 16, characterized in that a solvent (B) is most preferably cyclopentane, hexane, or mixtures thereof.
18. The process according to claim 15, characterized in that the proportion of solvent (B) is from 7 wt.% to 50 wt.% based on the total weight of the solvent.
19. The process according to claim 18, characterized in that the proportion of solvent (B) in the mixture is preferably from 9 wt.% to 20 wt.%.
20. The process according to claim 1, characterized in that the proportion of solvent (B) is most preferably from 10 wt.% to 15 wt.% based on the total weight of the solvent.
21. The process according to claim 1, characterized in that the aliphatic solvent for polymerization (A) is an inert organic solvent selected from heptane, hexane-heptane fraction of paraffin hydrocarbons of dearomatized catalytic reforming gasoline with boiling temperature limits of 65-75°C (nefras), as well as a cycloaliphatic solvent selected from cyclohexane, cycloheptan or mixtures thereof.
22. The process according to claim 21, characterized in that a solvent (A) is preferably cyclohexane or mixtures of cyclohexane and nefras.
23. The process according to claim 22, characterized in that a solvent (A) is most preferably a mixture of cyclohexane and nefras in a weight ratio of 65:35 to 70:30, respectively.
24. Branched polydiene obtained by the process of claims 1-23.
25. Branched polydiene characterized by a Mooney viscosity index of 39 to 52 Mooney units after modification, the polydispersity obtained in the range from 2.4 to 2.8, the content of 1.4-cis-units is more than 97 wt. %, mechanical loss tangent tgδ
(1200%) corresponding to the range from 6.41 to 2.87, plasticity is from 0.41 to 0.56, cold flow is from 17.4 to 35.8 mm/h and elastic recovery is from 0.99 to 2.17 mm.
26. Rubber compositions for tires and rubber products based on polydiene according to claims 24-25.
EP19956615.9A 2019-12-20 2019-12-20 Process for producing branched polydiene Pending EP4077406A4 (en)

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