USH2030H1 - Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds - Google Patents

Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds Download PDF

Info

Publication number
USH2030H1
USH2030H1 US08/084,685 US8468593A USH2030H US H2030 H1 USH2030 H1 US H2030H1 US 8468593 A US8468593 A US 8468593A US H2030 H USH2030 H US H2030H
Authority
US
United States
Prior art keywords
monomers
polymerization
addition
styrene
butadiene
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.)
Abandoned
Application number
US08/084,685
Inventor
Ronald James Hoxmeier
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kraton Polymers US LLC
Original Assignee
Shell Oil Co
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shell Oil Co filed Critical Shell Oil Co
Priority to US08/084,685 priority Critical patent/USH2030H1/en
Assigned to SHELL OIL COMPANY reassignment SHELL OIL COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HOXMEIER, RONALD JAMES
Assigned to CHASE MANHATTAN BANK, AS COLLATERAL AGENT, THE reassignment CHASE MANHATTAN BANK, AS COLLATERAL AGENT, THE SECURITY AGREEMENT Assignors: KRATON, POLYMERS U.S. LLC, FORMERLY KNOWN AS SHELL ELASTOMERS LLC
Assigned to SHELL ELASTOMERS LLC reassignment SHELL ELASTOMERS LLC ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SHELL OIL COMPANY
Application granted granted Critical
Publication of USH2030H1 publication Critical patent/USH2030H1/en
Assigned to UBS AG, STAMFORD BRANCH reassignment UBS AG, STAMFORD BRANCH SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KRATON POLYMERS U.S. LLC
Assigned to KRATON POLYMERS LLC reassignment KRATON POLYMERS LLC RELEASE BY SECURED PARTY Assignors: JPMORGAN CHASE BANK
Assigned to KRATON POLYMERS U.S. LLC reassignment KRATON POLYMERS U.S. LLC RELEASE BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: UBS AG, STAMFORD BRANCH
Abandoned legal-status Critical Current

Links

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
    • 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
    • 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
    • C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
    • C08F236/02—Copolymers 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
    • C08F236/04—Copolymers 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
    • C08F236/10—Copolymers 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 with vinyl-aromatic monomers

Definitions

  • the invention relates to solution polymerization of conjugated dienes and vinyl aromatic compounds.
  • the invention further relates to random copolymers of the conjugated dienes and vinyl aromatic compounds in which more than 60% of the monomer units are arranged in an arbitrary manner.
  • the solvents described for the known polymerization processes include essentially any aliphatic, cycloaliphatic or aromatic compound or a mixture of these compounds, provided that the compound is essentially inert. Cyclohexane alone or in combination with another compound is a highly preferred solvent in prior art processes.
  • the random copolymerization processes referred to above are suitably carried out at temperatures in the range of from 50° C.
  • compounds having a lower boiling point than cyclohexane, i.e. lower than 80° C. are added to the cyclohexane containing polymerization medium, in such concentrations that the solvency power is still sufficient, in order to provide enough vapor pressure to be able to remove the heat of polymerization by means of evaporative cooling.
  • the invention is a process for preparing a random copolymer of a conjugated diene and at least 50% by weight of a vinyl aromatic compound in a non-polar solvent with the aid of a chelating modifier to achieve at least 50% 1,2-addition of the conjugated diene.
  • the monomers are polymerized with a lithium initiator in the presence of a chelating modifier such as ethylene glycol diethyl ether.
  • the reaction proceeds slowly with continuous addition of monomers at 10° C. to 40° C. to give random polymerization. Control of the polymerization reaction is enhanced by adding the chelating modifier after initial polymerization of at least 5% of the monomers.
  • polymerization rate constants for the monomers in the non-polar solvents containing the chelating modifiers are maintained significantly higher than the rate of adding monomers, which results in more random distribution of the 1,2 polymerized conjugated diene throughout the polymer molecules.
  • the polymerization process according to the present invention is carried out at low temperatures from 10° C. to 40° C., the danger of thermal decomposition of the living polymer chain end is low.
  • Chelating modifiers which will result in at least 50% 1,2-polymerization in non-polar solvents include ethylene glycol diethyl ether, propylene glycol diethyl ether, or tetramethyl-ethylenediamine, preferably ethylene glycol diethyl ether.
  • the chelating modifier is present in the non-polar solvent, preferably cyclohexane, at a concentration from 500 ppm to 10,000 ppm, preferably 1,000 ppm to 4,000 ppm.
  • the totally needed quantity of initiator is added to a starting mixture of monomers under homogenization in a comparatively short time.
  • the amount of monomers contained in the starting mixture is from 1% to 10% by weight of the total amount of monomers to be reacted.
  • the chelating modifier is added after formation of small living polymers since earlier combination of the chelating modifier and the initiator results in an uncontrolled reaction between the chelating modifier and the initiator.
  • the loss of significant amounts of the initiator results in an uncontrolled increase in molecular weight and the loss of significant amounts of the chelating modifier results in an uncontrolled reduction in 1,2 addition.
  • the copolymerization reaction is preferably terminated by means of substances which kill the living polymer; this can be a proton releasing compound, for instance water, an alcohol, an amine or protonic acid, a coupling agent, or a functionalizing agent such as carbon dioxide or ethylene oxide.
  • a proton releasing compound for instance water, an alcohol, an amine or protonic acid, a coupling agent, or a functionalizing agent such as carbon dioxide or ethylene oxide.
  • the aromatic vinyl compound is preferably styrene, but may consist of another mono-vinyl aromatic compound for example: 1-vinylnaphthalene, 3,5-diethylstyrene, 4-n-propylstyrene, 2,4,6-trimethylstyrene, 4-phenylstyrene, 4-methylstyrene, 3,5-diphenylstyrene, 3-ethyl-1-vinylnaphthalene 8-phenyl-1-vinylnaphthalene or a mixture thereof or mixtures containing predominantly styrene.
  • 1-vinylnaphthalene 3,5-diethylstyrene
  • 4-n-propylstyrene 2,4,6-trimethylstyrene
  • 4-phenylstyrene 4-methylstyrene
  • 3,5-diphenylstyrene 3-ethyl-1-vinylnaphthalene 8-phenyl-1-viny
  • the conjugated diene is one capable of copolymerization with styrene or another aromatic vinyl compound and such that when polymerized with styrene or another selected aromatic vinyl compound or compounds, it provides a polymer having the desired properties.
  • the diene is preferably 1,3-butadiene, but may be another diene, for example, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene or 2,3-dimethyl-1,3-pentadiene or mixtures of them alone or with butadiene.
  • monomer addition preferably occurs by continuous addition of a premixed batch of the monomers to achieve the best distribution of the monomers.
  • periodic addition of separate portions of each monomer can be controlled to give good distribution of the monomers.
  • the monomer concentration in the reactor is kept substantially constant which facilitates the control of the process.
  • the lithium initiator is an alkyllithium compound, such as methylenedilithium, isopropyllithium, n-butyllithium, sec-butyllithium, amyllithium, 2-ethylhexyllithium, phenyllithium, ethylenedilithium, trimethylenedilithium, pentamethylenedilithium, 1,4-dilithiobenzene, 1,5-dilithiobenzene, 1,5-dilithionaphthalene and 1,3,5-trilithiumpentane.
  • the amount of initiator used in the process according to the present invention may vary within the wide limits to control molecular weight of the random copolymers.
  • the copolymer containing the reaction mixture is pumped to a polymer recovery area.
  • the principal step in recovery of the polymer comprises coagulation and eventual drying of the polymer to produce a crumb.
  • the cement may be coagulated by treatment with steam and/or hot water.
  • the cement may be sprayed into a hot water bath under such conditions that a crumb is formed.
  • the solvent is removed as a vapor and may be recovered and recycled as desired.
  • the resulting copolymer-water slurry is withdrawn and passed on to a dewatering screen where the water passes through the screen leaving the rubber crumb. This may be reslurried with cold water, drained and finally dried by known means.
  • the random copolymers are useful within a peak molecular weight range from 5,000 to 250,000, preferably from 25,000 to 50,000.
  • the random copolymers of the invention can be used as a replacement for styrene-butadiene rubbers (SBR's) in general, and are most useful in toner compositions for copy machines as taught in EP 477,577.
  • SBR's styrene-butadiene rubbers
  • the process of the invention is preferably the random polymerization of styrene and 1,3-butadiene in cyclohexane which contains ethylene glycol diethyl ether to make random copolymers having at least 70% by weight of the styrene and at least 70% 1,2-addition of the butadiene which are evenly distributed over most of the polymer molecule.
  • reaction mixture is intensively homogenized by means of an intensively working stirrer.
  • Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane.
  • the copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 273 ml of propylene glycol diethyl ether (sufficient to give 1000 ppm by weight), and 1.7 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 94 lbs of styrene and 31 lbs of butadiene were charged and premixed.
  • the polymerization was completed isothermally at 35° C. by adding the premixed monomer solution over a 60 minute period at a constant feed rate of 2 lbs/min.
  • the composition of the polymer chains was measured every 5 to 10 minutes during addition of the monomers. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
  • the random copolymer was determined by GPC analysis to have a peak MW of 40,300 vs. an expected peak MW of 33,000.
  • the 1,2-addition of the butadiene was 66.1% which varied from 65.5% to 67.4% during polymerization.
  • the styrene content was 75.6% by weight which varied from 73% to 75.6% during polymerization.
  • Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane.
  • the copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 1000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether, and 1.9 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed.
  • sec-butyllithium s-buLi
  • the polymerization was completed isothermally at 20° C. by adding the premixed monomer solution over a 120 minute period at a constant feed rate of 1 lb/min.
  • the composition of the polymer chains was measured every 15 minutes during addition of the monomers. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
  • the random copolymer was determined by GPC analysis to have a peak MW of 41,800 vs. an expected peak MW of 30,000.
  • the 1,2-addition of the butadiene was 76%.
  • the styrene content was 78% by weight which did not vary during polymerization.
  • Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane.
  • the copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 2000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether, and 3.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed.
  • sec-butyllithium s-buLi
  • the polymerization was completed isothermally at 15° C. by adding the premixed monomer solution over a 180 minute period at a constant feed rate of 0.7 lb/min. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
  • the random copolymer was determined by GPC analysis to have a peak MW of 90,500 vs. an expected peak MW of 18,300 as a result of a reaction between the ethylene glycol diethyl ether and the s-buLi.
  • the 1,2-addition of the butadiene was 80.1%.
  • the styrene content was 78.8% by weight.
  • Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane.
  • the copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 2000 ppm by weight of the reaction mixture of tetramethylethylenediamine (TMEDA), and 3.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed.
  • TEDA tetramethylethylenediamine
  • the polymerization was completed isothermally at 15° C. by adding the premixed monomer solution over a 240 minute period at a constant feed rate of 0.5 lb/min. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
  • the random copolymer was determined by GPC analysis to have a peak MW of 22,000 vs. an expected peak MW of 18,300 as a result of low reaction between the TMEDA and the s-buLi. However, the 1,2-addition of the butadiene was only 57%. The styrene content was 79% by weight.
  • Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane.
  • the copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed. The reactor was then charged with 375 lbs of the cyclohexane, 10 lbs of the mixed monomers, and 2.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent.
  • the polymerization proceeded for 10 minutes at 15° C. before addition of 4000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether. Polymerization was completed isothermally at 20° C. by adding the premixed monomer solution over a 150 minute period at a constant feed rate of 0.75 lb/min. The composition of the polymer chains was measured every 30 minutes during addition of the monomers. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
  • the random copolymer was determined by GPC analysis to have a peak MW of 35,300 vs. an expected peak MW of 27,000.
  • the 1,2-addition of the butadiene was 79.6%.
  • the styrene content was 79.1% by weight.
  • Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane.
  • the copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed. The reactor was then charged with 375 lbs of the cyclohexane, 10 lbs of the mixed monomers, and 3.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent.
  • the polymerization proceeded for 10 minutes at 15° C. before addition of 4000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether. Polymerization was completed isothermally at 20° C. by adding the premixed monomer solution over a 150 minute period at a constant feed rate of 0.75 lb/min. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
  • the random copolymer was determined by GPC analysis to have a peak MW of 24,100 vs. an expected peak MW of 18,300.
  • the 1,2-addition of. the butadiene was 79%.
  • the styrene content was 80.3% by weight.
  • Examples 5 and 6 establish a dramatic improvement in control of molecular weight for high 1,2-addition random copolymers resulting from conversion of s-buLi to small living polymer molecules prior to addition of the glycol ether in comparison to Example 3.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

Random copolymers of a conjugated diene and at least 50% by weight of a vinyl aromatic compound are prepared by slowly reacting the monomers in a non-polar solvent in the presence of a chelating modifier such as ethylene glycol diethyl ether which results in at least 50% 1,2-polymerization of the conjugated diene.

Description

FIELD OF THE INVENTION
The invention relates to solution polymerization of conjugated dienes and vinyl aromatic compounds. The invention further relates to random copolymers of the conjugated dienes and vinyl aromatic compounds in which more than 60% of the monomer units are arranged in an arbitrary manner.
BACKGROUND
Many processes for the preparation of substantially random copolymers of conjugated dienes and vinyl aromatic compounds are well known in the art. Typically, the solvents described for the known polymerization processes include essentially any aliphatic, cycloaliphatic or aromatic compound or a mixture of these compounds, provided that the compound is essentially inert. Cyclohexane alone or in combination with another compound is a highly preferred solvent in prior art processes.
Of all random polymerization processes, the one as disclosed in British patent specification No. 1,283,327, is particularly useful. First, a starting mixture is prepared from the solvent and part of the totally needed quantity of each of the monomers, subsequently the copolymerization is initiated by contacting this mixture with the initiator, and during copolymerization the monomer ratio in the reaction mixture is kept constant by addition of the remaining part of each of the monomers.
The random copolymerization processes referred to above are suitably carried out at temperatures in the range of from 50° C. Often compounds having a lower boiling point than cyclohexane, i.e. lower than 80° C., are added to the cyclohexane containing polymerization medium, in such concentrations that the solvency power is still sufficient, in order to provide enough vapor pressure to be able to remove the heat of polymerization by means of evaporative cooling.
SUMMARY
The invention is a process for preparing a random copolymer of a conjugated diene and at least 50% by weight of a vinyl aromatic compound in a non-polar solvent with the aid of a chelating modifier to achieve at least 50% 1,2-addition of the conjugated diene. The monomers are polymerized with a lithium initiator in the presence of a chelating modifier such as ethylene glycol diethyl ether. The reaction proceeds slowly with continuous addition of monomers at 10° C. to 40° C. to give random polymerization. Control of the polymerization reaction is enhanced by adding the chelating modifier after initial polymerization of at least 5% of the monomers.
DETAILED DESCRIPTION OF THE INVENTION
As a result of extensive research and experimentation a process has now been found in which the random polymerization of conjugated dienes and vinyl aromatic compounds is achieved in a non-polar solvent which contains a chelating modifier such as ethylene glycol diethyl ether to make random copolymers having at least 50% 1,2-addition of the conjugated diene. The random polymers have at least 50% by weight of the vinyl aromatic compound which is evenly distributed over most of the polymer molecule.
In the process according to the present invention polymerization rate constants for the monomers in the non-polar solvents containing the chelating modifiers are maintained significantly higher than the rate of adding monomers, which results in more random distribution of the 1,2 polymerized conjugated diene throughout the polymer molecules.
Since the polymerization process according to the present invention is carried out at low temperatures from 10° C. to 40° C., the danger of thermal decomposition of the living polymer chain end is low.
Chelating modifiers which will result in at least 50% 1,2-polymerization in non-polar solvents include ethylene glycol diethyl ether, propylene glycol diethyl ether, or tetramethyl-ethylenediamine, preferably ethylene glycol diethyl ether. The chelating modifier is present in the non-polar solvent, preferably cyclohexane, at a concentration from 500 ppm to 10,000 ppm, preferably 1,000 ppm to 4,000 ppm.
In order to control molecular weight of the random polymers, the totally needed quantity of initiator is added to a starting mixture of monomers under homogenization in a comparatively short time. The amount of monomers contained in the starting mixture is from 1% to 10% by weight of the total amount of monomers to be reacted. The chelating modifier is added after formation of small living polymers since earlier combination of the chelating modifier and the initiator results in an uncontrolled reaction between the chelating modifier and the initiator. The loss of significant amounts of the initiator results in an uncontrolled increase in molecular weight and the loss of significant amounts of the chelating modifier results in an uncontrolled reduction in 1,2 addition.
The copolymerization reaction is preferably terminated by means of substances which kill the living polymer; this can be a proton releasing compound, for instance water, an alcohol, an amine or protonic acid, a coupling agent, or a functionalizing agent such as carbon dioxide or ethylene oxide.
The aromatic vinyl compound is preferably styrene, but may consist of another mono-vinyl aromatic compound for example: 1-vinylnaphthalene, 3,5-diethylstyrene, 4-n-propylstyrene, 2,4,6-trimethylstyrene, 4-phenylstyrene, 4-methylstyrene, 3,5-diphenylstyrene, 3-ethyl-1-vinylnaphthalene 8-phenyl-1-vinylnaphthalene or a mixture thereof or mixtures containing predominantly styrene.
The conjugated diene is one capable of copolymerization with styrene or another aromatic vinyl compound and such that when polymerized with styrene or another selected aromatic vinyl compound or compounds, it provides a polymer having the desired properties. The diene is preferably 1,3-butadiene, but may be another diene, for example, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene or 2,3-dimethyl-1,3-pentadiene or mixtures of them alone or with butadiene.
After polymerization of the starting mixture, monomer addition preferably occurs by continuous addition of a premixed batch of the monomers to achieve the best distribution of the monomers. Although not preferred, periodic addition of separate portions of each monomer can be controlled to give good distribution of the monomers. As a result of the steps mentioned, the monomer concentration in the reactor is kept substantially constant which facilitates the control of the process.
Also special preference is given to the addition of the monomers during the copolymerization at a rate less than the rate at which the concerning monomer is consumed. Under these conditions the relative rate at which both monomers are applied during the copolymerization can be kept substantially constant at a value calculated beforehand and the heat development can be calculated in advance to control the temperature of the polymerization.
The lithium initiator is an alkyllithium compound, such as methylenedilithium, isopropyllithium, n-butyllithium, sec-butyllithium, amyllithium, 2-ethylhexyllithium, phenyllithium, ethylenedilithium, trimethylenedilithium, pentamethylenedilithium, 1,4-dilithiobenzene, 1,5-dilithiobenzene, 1,5-dilithionaphthalene and 1,3,5-trilithiumpentane. The amount of initiator used in the process according to the present invention may vary within the wide limits to control molecular weight of the random copolymers.
Generally at the end of the reaction the copolymer containing the reaction mixture is pumped to a polymer recovery area. The principal step in recovery of the polymer comprises coagulation and eventual drying of the polymer to produce a crumb. Thus the cement may be coagulated by treatment with steam and/or hot water. Alternatively, the cement may be sprayed into a hot water bath under such conditions that a crumb is formed. The solvent is removed as a vapor and may be recovered and recycled as desired. The resulting copolymer-water slurry is withdrawn and passed on to a dewatering screen where the water passes through the screen leaving the rubber crumb. This may be reslurried with cold water, drained and finally dried by known means.
The random copolymers are useful within a peak molecular weight range from 5,000 to 250,000, preferably from 25,000 to 50,000. The random copolymers of the invention can be used as a replacement for styrene-butadiene rubbers (SBR's) in general, and are most useful in toner compositions for copy machines as taught in EP 477,577.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The process of the invention is preferably the random polymerization of styrene and 1,3-butadiene in cyclohexane which contains ethylene glycol diethyl ether to make random copolymers having at least 70% by weight of the styrene and at least 70% 1,2-addition of the butadiene which are evenly distributed over most of the polymer molecule.
It is preferred that throughout the process the reaction mixture is intensively homogenized by means of an intensively working stirrer.
The following examples and comparative examples are presented to further illustrate the invention which is defined by the claims.
EXAMPLE 1
Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane. The copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 273 ml of propylene glycol diethyl ether (sufficient to give 1000 ppm by weight), and 1.7 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 94 lbs of styrene and 31 lbs of butadiene were charged and premixed.
The polymerization was completed isothermally at 35° C. by adding the premixed monomer solution over a 60 minute period at a constant feed rate of 2 lbs/min. The composition of the polymer chains was measured every 5 to 10 minutes during addition of the monomers. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
The random copolymer was determined by GPC analysis to have a peak MW of 40,300 vs. an expected peak MW of 33,000. The 1,2-addition of the butadiene was 66.1% which varied from 65.5% to 67.4% during polymerization. The styrene content was 75.6% by weight which varied from 73% to 75.6% during polymerization.
EXAMPLE 2
Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane. The copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 1000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether, and 1.9 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed.
The polymerization was completed isothermally at 20° C. by adding the premixed monomer solution over a 120 minute period at a constant feed rate of 1 lb/min. The composition of the polymer chains was measured every 15 minutes during addition of the monomers. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
The random copolymer was determined by GPC analysis to have a peak MW of 41,800 vs. an expected peak MW of 30,000. The 1,2-addition of the butadiene was 76%. The styrene content was 78% by weight which did not vary during polymerization.
EXAMPLE 3
Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane. The copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 2000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether, and 3.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed.
The polymerization was completed isothermally at 15° C. by adding the premixed monomer solution over a 180 minute period at a constant feed rate of 0.7 lb/min. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
The random copolymer was determined by GPC analysis to have a peak MW of 90,500 vs. an expected peak MW of 18,300 as a result of a reaction between the ethylene glycol diethyl ether and the s-buLi. The 1,2-addition of the butadiene was 80.1%. The styrene content was 78.8% by weight.
EXAMPLE 4
Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane. The copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. The reactor was charged with 375 lbs of the cyclohexane, 2000 ppm by weight of the reaction mixture of tetramethylethylenediamine (TMEDA), and 3.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed.
The polymerization was completed isothermally at 15° C. by adding the premixed monomer solution over a 240 minute period at a constant feed rate of 0.5 lb/min. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
The random copolymer was determined by GPC analysis to have a peak MW of 22,000 vs. an expected peak MW of 18,300 as a result of low reaction between the TMEDA and the s-buLi. However, the 1,2-addition of the butadiene was only 57%. The styrene content was 79% by weight.
EXAMPLE 5
Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane. The copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed. The reactor was then charged with 375 lbs of the cyclohexane, 10 lbs of the mixed monomers, and 2.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent.
The polymerization proceeded for 10 minutes at 15° C. before addition of 4000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether. Polymerization was completed isothermally at 20° C. by adding the premixed monomer solution over a 150 minute period at a constant feed rate of 0.75 lb/min. The composition of the polymer chains was measured every 30 minutes during addition of the monomers. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
The random copolymer was determined by GPC analysis to have a peak MW of 35,300 vs. an expected peak MW of 27,000. The 1,2-addition of the butadiene was 79.6%. The styrene content was 79.1% by weight.
EXAMPLE 6
Styrene and 1,3-butadiene were copolymerized by means of sec-butyllithium (s-buLi) as the initiator in cyclohexane. The copolymerization was carried out in a reactor of 100 gallons capacity, which was provided with a vigorous stirrer. In a separate vessel, 97.5 lbs of styrene and 27.4 lbs of butadiene were charged and premixed. The reactor was then charged with 375 lbs of the cyclohexane, 10 lbs of the mixed monomers, and 3.1 moles of 1.4 M s-buLi initiator in cyclohexane solvent.
The polymerization proceeded for 10 minutes at 15° C. before addition of 4000 ppm by weight of the reaction mixture of ethylene glycol diethyl ether. Polymerization was completed isothermally at 20° C. by adding the premixed monomer solution over a 150 minute period at a constant feed rate of 0.75 lb/min. Polymerization continued eight additional half lives after the last addition of monomers. Polymerization was then terminated by addition of methanol, and the polymer was recovered by steam coagulation. The recovered polymer was ground to give a white granular powder followed by drying at 35° C. for 24 hours.
The random copolymer was determined by GPC analysis to have a peak MW of 24,100 vs. an expected peak MW of 18,300. The 1,2-addition of. the butadiene was 79%. The styrene content was 80.3% by weight.
Examples 5 and 6 establish a dramatic improvement in control of molecular weight for high 1,2-addition random copolymers resulting from conversion of s-buLi to small living polymer molecules prior to addition of the glycol ether in comparison to Example 3.

Claims (3)

What is claimed is:
1. An improved process for the preparation of a random copolymer of at least one conjugated diene and at least 50% by weight of a vinyl aromatic compound wherein the monomers are polymerized with a lithium initiator, the improvement comprising polymerizing at least 5% by weight of the monomers in a non-polar solvent prior to addition of a sufficient amount tetramethylethylenediamine to achieve 1,2-addition of at least 60%, and them slowly adding the remaining portion of the monomers to maintain a reaction temperature from 10° C. to 40° C.
2. The process of claim 1 wherein the conjugated diene is 1,3-butadiene and the vinyl aromatic compound is styrene.
3. The process of claim 2 wherein the monomers are premixed and the mixture of the monomers comprises at least 70 percent by weight of the styrene.
US08/084,685 1993-06-29 1993-06-29 Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds Abandoned USH2030H1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US08/084,685 USH2030H1 (en) 1993-06-29 1993-06-29 Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/084,685 USH2030H1 (en) 1993-06-29 1993-06-29 Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds

Publications (1)

Publication Number Publication Date
USH2030H1 true USH2030H1 (en) 2002-06-04

Family

ID=22186582

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/084,685 Abandoned USH2030H1 (en) 1993-06-29 1993-06-29 Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds

Country Status (1)

Country Link
US (1) USH2030H1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6657028B1 (en) * 2002-08-01 2003-12-02 Albemarle Corporation Anionic polymerization process

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884490A (en) * 1958-05-23 1961-12-13 Phillips Petroleum Co Copolymers
US3301840A (en) * 1964-09-17 1967-01-31 Phillips Petroleum Co Preparation of polymers of conjugated dienes using organolithium/polar compound catalyst systems
GB1283327A (en) * 1970-04-16 1972-07-26 Shell Int Research Process for the discontinuous copolymerization of conjugated dienes containing at most five carbon atoms, and vinylaromatic compounds
US4230841A (en) * 1979-01-31 1980-10-28 The Goodyear Tire & Rubber Company Process for medium vinyl polybutadiene
US4429091A (en) * 1983-03-09 1984-01-31 The Firestone Tire & Rubber Company Oligomeric oxolanyl alkanes as modifiers for polymerization of dienes using lithium-based initiators
EP0128607A1 (en) 1983-06-13 1984-12-19 Shell Internationale Researchmaatschappij B.V. Elastomeric copolymers, their preparation and their use
US4696986A (en) * 1986-08-12 1987-09-29 The Goodyear Tire & Rubber Company Modifier for lithium catalysts
EP0477512A1 (en) 1990-09-24 1992-04-01 Xerox Corporation Toner and developer compositions with liquid glass resins
US5194535A (en) * 1991-06-10 1993-03-16 Shell Oil Company Process for production of alkadiene-based polymer of increased vinyl content

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB884490A (en) * 1958-05-23 1961-12-13 Phillips Petroleum Co Copolymers
US3301840A (en) * 1964-09-17 1967-01-31 Phillips Petroleum Co Preparation of polymers of conjugated dienes using organolithium/polar compound catalyst systems
GB1283327A (en) * 1970-04-16 1972-07-26 Shell Int Research Process for the discontinuous copolymerization of conjugated dienes containing at most five carbon atoms, and vinylaromatic compounds
US4230841A (en) * 1979-01-31 1980-10-28 The Goodyear Tire & Rubber Company Process for medium vinyl polybutadiene
US4429091A (en) * 1983-03-09 1984-01-31 The Firestone Tire & Rubber Company Oligomeric oxolanyl alkanes as modifiers for polymerization of dienes using lithium-based initiators
EP0128607A1 (en) 1983-06-13 1984-12-19 Shell Internationale Researchmaatschappij B.V. Elastomeric copolymers, their preparation and their use
US4696986A (en) * 1986-08-12 1987-09-29 The Goodyear Tire & Rubber Company Modifier for lithium catalysts
EP0477512A1 (en) 1990-09-24 1992-04-01 Xerox Corporation Toner and developer compositions with liquid glass resins
US5194535A (en) * 1991-06-10 1993-03-16 Shell Oil Company Process for production of alkadiene-based polymer of increased vinyl content

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6657028B1 (en) * 2002-08-01 2003-12-02 Albemarle Corporation Anionic polymerization process

Similar Documents

Publication Publication Date Title
AU605370B2 (en) Elastomeric compositions, process for the preparation thereof and tyres containing them
CA1340469C (en) Capped polydienes
DE10039357B4 (en) Process for the preparation of styrene-butadiene rubber
JPH0391516A (en) Block polymer having narrow molecular weight distribution and manufacture thereof
EP3103820A1 (en) Novel anionic polymerization initiator and method for preparing conjugated diene-based polymer using same
DE69415861T2 (en) Solubilized anionic polymerization initiators and products made from them
CA2023218C (en) Process for the preparation of copolymers of conjugated dienes and vinyl aromatic compounds
US5001196A (en) Process for preparation of diene type polymer rubber
US5171800A (en) Anionic polymerization with bifunctional initiators
US5147939A (en) Unsaturated, elastomeric, asymmetrically coupled block copolymer, a single batch process for its manufacture and its use for the production of tire components
US3887532A (en) Method of coagulating latices
US3435011A (en) Modified polymers of conjugated dienes
US3801554A (en) Lithium alkenoxides as modifiers in organolithium initiated polymerization
JP3157034B2 (en) Method for producing carboxyl group-containing conjugated diene polymer
JPH05403B2 (en)
USH2030H1 (en) Process for the preparation of random copolymers of conjugated dienes and vinyl aromatic compounds
US4087484A (en) Process for producing transparent block copolymer resin
EP0998502B1 (en) Enhanced hydrogenation catalyst removal from block copolymers by reduction in polymer cement viscosity by increasing the vinyl content of the block copolymers
Santarella et al. Cationic polymerization of dienes III. Polymerization of 1, 3-pentadiene initiated by ferric chloride in hexane
US6221975B1 (en) Process for preparing random copolymer functionalized at both terminals
EP1319673A1 (en) Polymers, modified by functionalised groups
JPH0475244B2 (en)
JPS63297410A (en) Production of styrene-butadiene copolymer
JP6754007B2 (en) How to generate polydiene
JP3992365B2 (en) Method for producing chloroprene polymer and polymerization catalyst thereof

Legal Events

Date Code Title Description
AS Assignment

Owner name: SHELL OIL COMPANY, TEXAS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HOXMEIER, RONALD JAMES;REEL/FRAME:010741/0991

Effective date: 19930628

AS Assignment

Owner name: CHASE MANHATTAN BANK, AS COLLATERAL AGENT, THE, NE

Free format text: SECURITY AGREEMENT;ASSIGNOR:KRATON, POLYMERS U.S. LLC, FORMERLY KNOWN AS SHELL ELASTOMERS LLC;REEL/FRAME:011571/0342

Effective date: 20010228

AS Assignment

Owner name: SHELL ELASTOMERS LLC, TEXAS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SHELL OIL COMPANY;REEL/FRAME:012090/0627

Effective date: 20010228

STCF Information on status: patent grant

Free format text: PATENTED CASE

AS Assignment

Owner name: UBS AG, STAMFORD BRANCH, CONNECTICUT

Free format text: SECURITY INTEREST;ASSIGNOR:KRATON POLYMERS U.S. LLC;REEL/FRAME:014242/0281

Effective date: 20031223

AS Assignment

Owner name: KRATON POLYMERS LLC, TEXAS

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:JPMORGAN CHASE BANK;REEL/FRAME:018224/0293

Effective date: 20010228

AS Assignment

Owner name: KRATON POLYMERS U.S. LLC, TEXAS

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:UBS AG, STAMFORD BRANCH;REEL/FRAME:025880/0216

Effective date: 20110211