Classifications

• • 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
  • C08F293/00—Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule
• • 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
  • C08F4/46—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 selected from alkali metals
  • C08F4/48—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 selected from alkali metals selected from lithium, rubidium, caesium or francium
• • 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
  • C08F12/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
  • C08F12/02—Monomers containing only one unsaturated aliphatic radical
  • C08F12/04—Monomers containing only one unsaturated aliphatic radical containing one ring
  • C08F12/06—Hydrocarbons
  • C08F12/08—Styrene
• • 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
  • C08F212/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring
  • C08F212/02—Monomers containing only one unsaturated aliphatic radical
  • C08F212/04—Monomers containing only one unsaturated aliphatic radical containing one ring
  • C08F212/06—Hydrocarbons
  • C08F212/08—Styrene

Definitions

• the present invention relates to a process for the preparation of polymers of vinyl aromatics and of vinyl aromatic-diene block copolymers with the aid of a modified n-alkyl lithium initiator and its use as an initiator for the anionic polymerization.
• Block copolymers of vinylaromatics (e.g., styrene) and dienes (e.g., butadiene) are copolymers of several juxtaposed or otherwise linked polymer molecule regions (so-called blocks) which are more or less uniform in structure.
• blocks polymer molecule regions
• diene monomers they can, at a certain temperature, have a total of elastomeric, i. have elastomeric properties or rigid, non-rubbery properties, i. they behave outwardly either totally rubber elastic, similar to a polydiae and have e.g. meaning as so-called thermoplastic elastomers, or as transparent, tough-rigid styrene polymers.
• SB-rubbers can not be processed like thermoplastics but, like ordinary diene polymers, have to be vulcanised for use, ie crosslinked, which greatly prolongs their processing time.
• the disadvantage of this method is a significant increase of 1, 2-linkages by at least 3-5% in the subsequent butadiene polymerization, which leads to a higher glass transition temperature, ie poorer elastomeric properties and an increased sensitivity to oxidation and crosslinking.
• thermoplastic elastomers with sec-butyllithium as initiator in cyclohexane is known.
• the styrene polymerization gives the desired, mechanically advantageous narrow-distribution living polymers under these conditions, but sec-butyllithium is more expensive than n-BuLi and especially at room temperature not storage stable. It forms with the release of butene a pyrophoric lithium hydride sludge, which spontaneously ignites when in contact with air.
• the present invention was therefore based on the object to remedy the aforementioned disadvantages.
• the invention relates to a process for the preparation of vinylaromatic homopolymers and vinylaromatic diene block copolymers by anionic polymerization, characterized in that a modified n-alkyllithium initiator is used for the polymerization of a vinylaromatic, which by reaction of n-alkyllithium, dissolved in an inert solvent, with a diene in a molar ratio of 1: 1 to 1: 50 at a temperature of -20 to 100 ° C is available
• a modified alkyllithium initiator according to the invention is an alkyllithium initiator generally containing 1 to 50, preferably 1 to 20, in particular 1 to 10, particularly preferably 1 to 5, and very particularly preferably 1 to 3, copolymerized monomer units of a diene understand.
• the following dienes are suitable: 1,3-dienes, preferably 1,3-butadiene, isoprene, 2,3-dimethylbutadiene and / or 1,3-pentadiene, more preferably 1,3 butadiene.
• Suitable n-alkyllithium is C 1 -C 22 -alkyl lithium, preferably C 4 -C 8 -alkyllithium, particularly preferably n-butyllithium.
• the reaction of the diene with n-alkyllithium can preferably be carried out in the presence of an inert solvent.
• n-Alkyllithium is used as a solution of n-alkyl lithium in an inert solvent, which usually has a concentration of 0.1 to 20 wt .-%, preferably 1 to 15 wt .-%, particularly preferably 5 to 13 parts by weight. % having.
• n-butyllithium solutions are generally present as 12% by weight solutions.
• the modified alkyllithium initiator used in the process according to the invention it is advantageous to initially charge the n-alkyllithium solution, optionally with the addition of further inert solvent, and then at temperatures from -20 to 100 ° C., preferably from 20 to 80 ° C., more preferably 35 to 75 ° C, in particular 50 to 75 ° C, and a pressure of 0.5 to 100 bar, preferably 1 to 10 bar, particularly preferably 2 to 5 bar, the diene, optionally with the addition of an inert solvent, admit.
• the reaction is usually carried out under an inert gas atmosphere. It is also advantageous for rapid mixing of the reaction mixture by means of a high-speed stirrer such. B. to provide a propeller stirrer. Also suitable are continuous flow through mixing chambers without moving parts, in which the two reaction components are injected under pressure so that there is a rapid turbulence and mixing.
• Suitable inert solvents are, for example, aliphatic and / or aromatic hydrocarbons, for example C 5 - to C 2 o-alkane, such as n-pentane, iso-pentane, n-hexane, isohexane, heptane, octane or isooctane, a C 4 - to C 2 o-cycloalkane such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, methylcyclohexane and decalin, aromatics and alkylaromatics such as benzene, toluene, ortho-, meta- and para-xylene, ethylbenzene, n- and isopropylbenzene, tert-butylbenzene, naphthalene, methylnaphthalene and tetralin and
• Cyclohexane or a mixture of cyclohexane and n-hexane is preferably used. Preference is furthermore given to mixtures of cycclohexane with an inert solvent whose melting point is ⁇ 4 ° C.
• the inert solvents which are used for the n-alkyllithium solution and for its further dilution or for dilution of the diene may be the same or different, preferably the same.
• the reaction is preferably carried out under an inert gas atmosphere.
• Suitable inert gases are nitrogen, noble gases such as argon, helium, neon, krypton, xenon or hydrocarbons such as methane, ethane, propane, butane or hydrogen, preferably nitrogen or argon, particularly preferably nitrogen.
• the volume ratio of inert solvent to n-alkyl lithium solution is generally 0: 1 to 10: 1, preferably 0.1: 1 to 8: 1, more preferably 0.5: 1 to 2: 1, in particular 1: 1.
• the volume ratio of inert solvent to diene is generally 0: 1 to 10: 1, preferably 0.1: 1 to 8: 1, more preferably 0.5: 1 to 2: 1, in particular 1: 1.
• the volume ratio of inert solvent to diene is usually 0.5: 1 to 2: 1, preferably 0.7: 1 to 1, 5: 1, more preferably 1: 1.
• the molar ratio of n-alkyllithium to diene is generally 1: 1 to 1:50, preferably 1: 1 to 1:20, preferably 1: 1 to 1:10, particularly preferably 1: 1, 2 to 1: 5 and most preferably 1: 1, 5 to 1: 3.
• the modified alkyllithium initiator used in the process of the invention as described above should be substantially free of monomeric diene, i. the concentration of monomeric diene with respect to the initiator is usually 0 to 1, 000 ppm, preferably 0 to 100 ppm, more preferably 0 to 10 ppm.
• the modified alkyllithium initiator obtained may optionally be intercalated under inert gas or used directly for the process according to the invention.
• the initiator is cooled, for example, by flowing through a heat exchanger after the preparation to temperatures of preferably below 60 ° C.
• the anionic homo- or copolymerization of vinyl aromatic monomers is known (see K. Knoll in Kunststoffhandbuch polystyrene: Volume 4, Gausepohl and Geliert Hrsg, Hanser Verlag, 1996, pages 145-160).
• block copolymers based on vinylaromatic and diene monomer units by sequential anionic polymerization ibid. 161-164. Reference is expressly made to the aforementioned methods.
• the modified alkyl lithium initiator in an inert solvent such as preferably cyclohexane with a vinyl aromatic such as preferably styrene at temperatures from 0 to 120 ° C, preferably 20 to 100 ° C, particularly preferably 30 to 90 ° C, especially 35 to 80 ° C and a pressure of 0.3 to 25 bar, preferably 0.5 to 5 bar, more preferably reacted 0.5 to 2 bar.
• an inert solvent such as preferably cyclohexane with a vinyl aromatic such as preferably styrene
• Suitable vinyl aromatics are styrene, ⁇ -methylstyrene, o-, m-, p-substituted alkylstyrenes, vinylnaphthalene and / or 1,1-diphenylethylene, preferably styrene, ⁇ -methylstyrene, o-, m-, p-substituted alkylstyrenes, such as , m- and / or p-methylstyrene, particularly preferably styrene.
• one or more different vinyl aromatic compounds can be used.
• the modified alkyllithium initiator may be added under the above conditions to a mixture of an inert solvent such as cyclohexane and a vinyl aromatic such as preferably styrene. It is also possible to add the modified alkyllithium initiator directly after its preparation in still warm or hot state.
• narrowly distributed, linear living, i. still polymerizable, ie active and thus reactive polymer chains of vinyl aromatics obtained, for example, in a subsequent polymerization step with a diene or a mixture of a vinyl aromatic such as styrene and a diene can be reacted.
• the sequential anionic polymerization is carried out as a block polymerization of a vinyl aromatic and a diene.
• Suitable dienes for the block polymerization are 1,3-dienes, preferably 1,3-butadiene, isoprene, 2,3-dimethylbutadiene and / or 1,3-pentadiene, particularly preferably 1,3-butadiene and isoprene, very particularly preferably 1, 3-butadiene.
• One or more different dienes can be used in the process according to the invention.
• the sequential anionic polymerization is carried out as a bulk polymerization of styrene and 1, 3-butadiene.
• a diene block with a blurred transition to another vinyl aromatic block is obtained without the addition of a randomizer.
• a randomizer for example, THF or potassium alcoholates (e.g., potassium tertiary amylate) can be used.
• a random vinyl aromatic / diene block can be obtained by adding a mixture of a vinyl aromatic and a diene to the living polymer chain.
• a suitable potassium / lithium ratio is preferably in the range from 1:30 to 1:40, particularly preferably 1:37.
• the number, length, sequence and composition of the blocks is arbitrary.
• the process according to the invention is particularly suitable for preparing vinyl aromatic-diene block copolymers having at least one external vinylaromatic block.
• the polymer chain can be protonated and deactivated, or a symmetrical linear polymer with twice the molecular weight can be obtained by addition of a bi- or oligofunctional coupling agent.
• a star polymer can be obtained.
• the modified alkyllithium initiator followed by monomer may in turn be added once or several times to give a bi- or oligomodal molecular weight distribution. If the living chains are treated with an oligofunctional coupling agent, unsymmetrical star polymers are obtained.
• the modified alkyllithium initiator is stable, for example at 60 ° C and can be stored as a solution under an inert gas atmosphere until further use.
• the vinylaromatic homo- and block copolymers prepared with the aid of the initiator used according to the invention are generally transparent and, depending on the composition, may have elastomeric behavior or a toughened mechanism.
• Another object of the invention is the use of modified n-Alkylllithium containing 1 to 50, preferably 1 to 20, especially 1 to 10, more preferably 1 to 5, and most preferably 1 to 3, copolymerized monomer units of a diene as an initiator for the anionic Polymerization of vinylaromatics.
• the styrene originates from the styrene distillation of the styrene factory and was used without further purification, the cyclohexane was dried at room temperature over an aluminum oxide column and the butadiene was dried at -10 ° C. over aluminum oxide and freed from the stabilizer.
• the GPC measurements were carried out according to DIN 55672 using a refractive index detector ERC-RI-101.
• a 10 l stainless steel autoclave equipped with a crossbeam brewer which could be simultaneously heated and cooled, was prepared by purging with nitrogen and boiling with cyclohexane / sec.-BuLi. Cyclohexane was then introduced and the amounts of initiator and monomers indicated in the respective examples and optionally further solvent were added.
• the temperature of the reaction mixture was controlled by heating or cooling the reactor jacket.
• the further workup is carried out by the usual methods.
• isopropanol was added to protonate the carbanions.
• the solids content of the sample was 30% by weight.
• the following data was obtained from the GPC measurement:
• the GPC diagram shows a bimodal molecular weight distribution.
• the solids content of the sample was 30% by weight.
• the GPC diagram shows a monomodal distribution.
• the solids content of the sample was 30% by weight.
• the following data was obtained from the GPC measurement:
• the solids content of the sample was 30% by weight.

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• 2013
  • 2013-06-24 WO PCT/EP2013/063097 patent/WO2014001234A1/de not_active Ceased
  • 2013-06-24 KR KR1020147035890A patent/KR20150022872A/ko not_active Withdrawn
  • 2013-06-24 US US14/409,275 patent/US20150166710A1/en not_active Abandoned
  • 2013-06-24 EP EP13731131.2A patent/EP2864375B1/de not_active Not-in-force
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  • 2013-06-24 JP JP2015519014A patent/JP6388577B2/ja not_active Expired - Fee Related
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