EP1682592A1 - Procede de polymerisation anionique de monomeres en alpha-methylstyrene - Google Patents

Procede de polymerisation anionique de monomeres en alpha-methylstyrene

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Publication number
EP1682592A1
EP1682592A1 EP04790620A EP04790620A EP1682592A1 EP 1682592 A1 EP1682592 A1 EP 1682592A1 EP 04790620 A EP04790620 A EP 04790620A EP 04790620 A EP04790620 A EP 04790620A EP 1682592 A1 EP1682592 A1 EP 1682592A1
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EP
European Patent Office
Prior art keywords
styrene
polymerization
monomers
impact
methylstyrene
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EP04790620A
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German (de)
English (en)
Inventor
Philippe Desbois
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BASF SE
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BASF SE
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
    • C08L51/04—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to rubbers
    • 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
    • C08F279/00—Macromolecular compounds obtained by polymerising monomers on to polymers of monomers having two or more carbon-to-carbon double bonds as defined in group C08F36/00
    • C08F279/02—Macromolecular compounds obtained by polymerising monomers on to polymers of monomers having two or more carbon-to-carbon double bonds as defined in group C08F36/00 on to polymers of conjugated dienes
    • 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
    • C08F287/00—Macromolecular compounds obtained by polymerising monomers on to block polymers
    • 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
    • C08F293/005—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 using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
    • 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
    • C08F295/00—Macromolecular compounds obtained by polymerisation using successively different catalyst types without deactivating the intermediate polymer
    • 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
    • C08F297/00—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
    • C08F297/02—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type
    • C08F297/04—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type polymerising vinyl aromatic monomers and conjugated dienes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
    • C08L53/02—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers of vinyl-aromatic monomers and conjugated dienes

Definitions

  • the invention relates to a process for the preparation of impact-resistant polystyrene from diene monomers and styrene monomers by anionic or anionic and radical polymerization, characterized in that
  • a rubber solution is prepared from the diene monomers, or from the diene monomers and the styrene monomers, by anionic polymerization in the presence of a solvent and an initiator composition, polymerizing at at least 20 ° C. and using ⁇ -methylstyrene as the sole solvent, and
  • Styrene monomer is added to this rubber solution and the mixture obtained is polymerized anionically or radically in the presence of an initiator composition to give the impact-resistant polystyrene.
  • the invention also relates to the impact-resistant polystyrene obtainable by the process mentioned, the use of impact-resistant polystyrene for the production of moldings, foils, fibers and foams, and the moldings, foils, fibers and foams made from the impact-resistant polystyrene.
  • the polymers mentioned can be produced by various polymerization processes, for example by radical or anionic polymerization.
  • the polymers obtained by anionic polymerization have a number of advantages over products obtained by radical means, including lower residual monomer and oligomer contents. Radical and anionic polymerization are fundamentally different. In the case of radical polymerization, the reaction proceeds via free radicals and, for example, peroxidic initiators are used, whereas the anionic polymerization proceeds via "living" carbanions and, for example, alkali metal organanyl compounds are used as initiators. After the monomers have been consumed, the anionic polymerization is preferably terminated with a chain terminator, for example a protic substance such as water or alcohols. The anionic polymerization proceeds much faster and leads to higher sales than the radical polymerization. The temperature control of the exothermic reaction is difficult due to the high speed.
  • styrene monomer and further solvent are then added to the dilute rubber solution and the mixture is polymerized to give the end product.
  • the anionic polymerization of styrene and / or butadiene is described for example in WO 98/07765 and WO 98/07766.
  • the solvent used for the dilution increases the raw material costs and reduces the amount of polymer produced, since the reaction mixture obtained has comparatively low solids contents.
  • the solvent must be removed again when working up the reaction mixture onto the impact-resistant polystyrene, for example by (usually several) degassing steps. This reduces the economics of the process.
  • the task was to remedy the disadvantages described.
  • the object was to provide an alternative method for producing impact-resistant polystyrene that has improved economy.
  • the process should do without inert solvents.
  • the process should be able to produce polymer solutions with a high solids content.
  • a rubber solution is prepared from diene monomers, or from diene monomers and styrene monomers, by anionic polymerization in the presence of a solvent and an initiator composition.
  • Suitable diene monomers are all polymerizable dienes, in particular 1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethylbutadiene, isoprene, piperylene or mixtures thereof.
  • 1,3-Butadiene (short: butadiene) is preferred.
  • All vinylaromatic monomers are suitable as styrene monomers, for example styrene, p-methylstyrene, ethylstyrene, tert-butylstyrene, vinylstyrene, vinyltoluene, 1,2-diphenylethylene, 1,1-diphenylethylene or mixtures thereof.
  • Styrene is particularly preferably used.
  • styrene is used as the styrene monomer and butadiene or isoprene is used as the diene monomer. Mixtures of these monomers can also be used.
  • ⁇ -methylstyrene is used as the sole solvent in step a) of the process.
  • no other inert solvents for example aliphatic, isocyclic or aromatic hydrocarbons or hydrocarbon mixtures, such as benzene, toluene, ethylbenzene, xylene, cumene, hexane, heptane, octane or cyclohexane, are used.
  • the wording “as the only solvent” is not intended to exclude small amounts of solvents which may be present in the initiator composition or in other auxiliaries, ie the reaction mixture may, for example, contain small amounts of an initiator or retarder solvent. The amount of these solvents is considerably less than the amount of solvent required in anionic solution polymerization, and is far from sufficient as a solvent for the polymerization.
  • the amount of the solvent ⁇ -methylstyrene is usually 5 to 95, preferably 20 to 90 and particularly preferably 60 to 80% by weight, based on the total amount of the monomers used.
  • the initiator composition preferably contains an alkali metal organyl or an alkali metal hydride or mixtures thereof.
  • the alkali metal compounds act as anionic polymerization initiators.
  • Suitable alkali metal organyls are e.g. mono-, bi- or multifunctional alkali metal alkyls, aryls or aralkyls, in particular organolithium compounds such as ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, phenyl, diphenylhexyl , Hexamethylenedi-, Butadienyl-, Isoprenyl-, Polystyryl- lithium or the multifunctional compounds 1,4-Dilithiobutan, 1, 4-Dilithio-2-buten or 1,4-Dilithiobenzol. Sec-butyllithium is preferably used.
  • Alkali metal hydrides as initiators are less preferred in step a) of the process according to the invention, but particularly preferred in step b). They are usually used together with retarders, e.g. aluminum organyls (see below). Suitable alkali metal hydrides are, for example, lithium hydride, sodium hydride or potassium hydride. To control the reaction rate, additives which reduce the rate of polymerization, so-called retarders as described in WO 98/07766, can be added. In rubber synthesis, ie in step a) of the process according to the invention, retarders can be dispensed with in some cases, for example if homopolybutadiene rubber is produced. In contrast, in step b), ie in the production of the impact-resistant polystyrene, the initiator composition additionally contains a retarder, particularly preferably an aluminum organyl.
  • a retarder particularly preferably an aluminum organyl.
  • Suitable retarders are, for example, metal organyles of an element of the second or third main group or of the second subgroup of the periodic table.
  • the organyls of the elements Be, Mg, Ca, Sr, Ba, B, Al, Ga, In, TI, Zn, Cd, Hg can be used.
  • Aluminum organyles, magnesium organyles or zinc organyls, or mixtures thereof, are preferably used as retarders.
  • Organyls are understood to mean the organometallic compounds of the elements mentioned with at least one metal-carbon ⁇ bond, in particular the alkyl or aryl compounds.
  • the metal organyls can also contain hydrogen, halogen or organic radicals bound via heteroatoms, such as alcoholates or phenolates, on the metal. The latter can be obtained, for example, by whole or partial hydrolysis, alcoholysis or aminolysis. Mixtures of different metal organyls can also be used.
  • aluminum organyls those of the formula R3AI can be used, the radicals R independently of one another being hydrogen, halogen, C 1 -C 6 -alkyl or C 6 . 2 mean o-aryl.
  • Preferred aluminum organyls are the aluminum trialkyls, such as triethyl aluminum, tri-iso-butyl aluminum, tri-n-butyl aluminum, tri-iso-propyl aluminum, tri-n-hexyl aluminum. Triisobutylaluminum (TIBA) or triethylaluminum (TEA) is particularly preferably used.
  • Aluminum organyls which can be used are those which result from partial or complete hydrolysis, alcoholysis, aminolysis or oxidation of alkyl or arylaluminum compounds. Examples are diethyl aluminum ethoxide, diisobutyl aluminum ethoxide, diisobutyl (2,6-di-tert-butyl-4-methylphenoxy) aluminum (CAS No. 56252-56-3), methylaluminoxane, isobutylated Methylaluminoxane, isobutylaluminoxane, tetraisobutyldialuminoxane or bis (diisobutyl) alumina.
  • Suitable magnesium organyls are those of the formula R 2 Mg, where the radicals R have the meaning given above.
  • Dialkyl magnesium compounds in particular the ethyl, propyl, butyl, hexyl or octyl compounds available as commercial products, are preferably used.
  • the (n-butyl) (s-butyl) magnesium which is soluble in hydrocarbons is particularly preferably used.
  • Zinc organyls which can be used are those of the formula R 2 Zn, where the radicals R have the meaning indicated above.
  • Preferred zinc organyls are dialkyl zinc compounds, in particular with ethyl, propyl, butyl, hexyl or octyl as the alkyl radical. Diethyl zinc is particularly preferred.
  • the required amount of polymerization initiators depends, among other things. according to the desired molecular weight (molar mass) of the polymer to be produced, the type and amount of retarder used and the polymerization temperature. As a rule, 0.0001 to 10, preferably 0.001 to 1 and particularly preferably 0.01 to 0.2 mol% of alkali metal organyl are used, based on the total amount of the monomers used.
  • the required amount is determined, among other things. depending on the type and amount of retarders used, and on the polymerization temperature. Usually 0.0001 to 10, preferably 0.001 to 5 and especially 0.01 to 2 mol% retarder compound are used, based on the total amount of the monomers used.
  • the molar ratio of initiator to retarder can vary within wide limits. For example, according to the desired retardation effect, the polymerization temperature, the type and amount (concentration) of the monomers used, and the desired molecular weight of the polymer.
  • the initiator composition is preferably prepared using a suspension or solvent (hereinafter referred to collectively as solvents).
  • solvents are, in particular, inert hydrocarbons, more specifically aliphatic, cycloaliphatic or aromatic hydrocarbons, such as cyclohexane, methylcyclohexane, pentane, hexane, heptane, isooctane, benzene, toluene, xylene, ethylbenzene, decalin or paraffin oil, or mixtures thereof. Toluene is particularly preferred.
  • the amount of solvents is small compared to the amount of ⁇ -methylstyrene used and is far from sufficient as a solvent for the polymerization, which is why the solvents are not among the solvents within the meaning of the claims.
  • the initiator composition can be allowed to age (age) after the addition of the retarder.
  • age age
  • the ripening or aging of the freshly prepared initiator composition improves the reproducibility of the anionic polymerization.
  • the observed aging process is presumably due to a complex formation of the metal compounds, which is slower than the mixing process.
  • the ripening time is about 2 minutes, preferably at least 5 minutes, in particular at least 20 minutes, and up to several hours, for example 1 to 480 hours.
  • Initiator components can be carried out in conventional mixing units, preferably in units which can be supplied with inert gas.
  • the polymerization temperature in step a) of the process is at least 20 ° C.
  • Polymerization is preferably carried out at 20 to 150, particularly preferably 40 to 100 and in particular 60 to 100 ° C. Temperatures of 60 to 80 ° C. are very particularly preferred.
  • the polymerization temperature is adjusted by conventional devices, e.g. Temperature control of the reactor via the outer wall or immersed heat exchangers, evaporative cooling, and / or by means of the heat of polymerization released.
  • the other polymerization conditions for example pressure and polymerization time, are usually chosen to be similar to the anionic polymerization processes of styrene and diene monomers known to those skilled in the art.
  • step a) is usually not followed by addition after the polymerization of a chain terminating agent such as water or alcohol.
  • a chain terminating agent such as water or alcohol.
  • the reaction can be "frozen” by adding a molar excess, based on the initiator, to the retarder, see below.
  • Step a) of the process according to the invention can be carried out batchwise or continuously, in any pressure-resistant and temperature-resistant reactor, it being possible in principle to use backmixing or non-backmixing reactors (ie reactors with stirred tank or tubular reactor behavior).
  • backmixing or non-backmixing reactors ie reactors with stirred tank or tubular reactor behavior.
  • the process sequence used in particular, and other parameters, such as temperature and possibly temperature profile the process leads to polymers with high or low molecular weight.
  • stirred tanks, tower reactors, loop reactors and tubular reactors or tube bundle reactors with or without internals are suitable. Internals can be static or movable internals.
  • the polymerization can be carried out in one or more stages. It is preferably carried out batchwise, for example in a stirred tank. Further details on the design of the reactors and the operating conditions can be found in the documents WO 98/07765 and WO 98/07766, to which reference is expressly made here.
  • step a) of the process a reaction mixture is obtained which contains the rubber polymer dissolved in ⁇ -methylstyrene.
  • the solvent ⁇ -methylstyrene is not or only to a small extent incorporated as a monomer in the polymer.
  • the rubber polymer preferably contains polymerized ⁇ -methylstyrene only in small amounts of 0 to 10, in particular 0 to 5% by weight of ⁇ -methylstyrene.
  • Rubber polymers include, for example, homopolymers such as polybutadiene (PB) and polyisoprene (PI), and copolymers such as styrene-butadiene block copolymers (S-B polymers).
  • the weight average molecular weights Mw for polybutadiene or polyisoprene are preferably 10,000 to 500,000, preferably 50,000 to 300,000 g / mol.
  • the block structure is essentially created by first anionically polymerizing styrene alone, creating a styrene block. After the styrene monomers have been consumed, the monomer is changed by adding monomeric butadiene and anionically polymerizing to a butadiene block polymer (so-called sequential polymerization).
  • the resulting two-block polymer S-B can be polymerized by renewed monomer change on styrene to a three-block polymer S-B-S, if desired.
  • the two styrene blocks can be of the same size (same molecular weight, that is, symmetrical structure S 1 -BS 1 ) or different sizes (different molecular weight, that is, asymmetrical structure S BS 2 ).
  • Block sequences SSB or SS 2 -B, or SBB or SB B 2 are of course also possible.
  • the indices for the block sizes are given above. The block sizes depend, for example, on the amounts of monomers used and the polymerization conditions.
  • the block copolymers mentioned can have a linear structure (described above). However, branched or star-shaped structures are also possible and preferred for some applications. Branched block copolymers are obtained in a known manner, e.g. by grafting polymer "side branches" onto a polymer backbone.
  • Star-shaped block copolymers are formed, for example, by reacting the living anionic chain ends with an at least bifunctional coupling agent.
  • an at least bifunctional coupling agent are described, for example, in U.S. Patent Nos. 3,985,830, 3,280,084, 3,675,554, and 4,091,053.
  • Epoxidized glycerides eg epoxidized linseed oil or soybean oil
  • silicon halides such as SiCl 4
  • divinylbenzene divinylbenzene
  • polyfunctional aldehydes, ketones, esters, anhydrides or epoxides are preferred.
  • Dichlorodialkylsilanes, dialdehydes such as terephthalaldehyde and esters such as ethyl formate are also particularly suitable for the dimerization.
  • dialdehydes such as terephthalaldehyde
  • esters such as ethyl formate
  • the individual star branches can be the same or different, in particular contain different blocks S, B, B / S or different block sequences. Further details on star-shaped block copolymers can be found, for example, in WO 00/58380.
  • the monomer names styrene and butadiene used above are also examples of other vinyl aromatics and dienes.
  • step b) of the process according to the invention styrene monomer is added to the rubber solution obtained in step a) and the mixture obtained is polymerized in the presence of an initiator composition anionically or radically to give the end product impact-resistant polystyrene.
  • Suitable styrene monomers are the styrene monomers already mentioned above, and also ⁇ -methylstyrene. Styrene is preferably used.
  • the initiator composition suitable for anionic polymerization has already been described in step a).
  • the initiator compositions used in step a) or step b) may differ from one another.
  • it preferably contains alkali metal organyls or (particularly preferred) alkali metal hydrides as the anionic polymerization initiator, and additionally a retarder, preferably an aluminum organyl.
  • step b) - with styrene as the added styrene monomer - an impact-resistant polystyrene with a hard matrix of styrene- ⁇ -methylstyrene copolymer is obtained, since the initiator composition mentioned incorporates ⁇ -Methylstyrene favored as a comomomer in the hard matrix.
  • a mixture of potassium hydride and TIBA is particularly preferably used in step b).
  • the molar ratio of retarder to initiator is expediently stated as the molar ratio of retarder metal (for example Al, Mg or Zn) to initiator metal (for example Li) and is 0.5: 1 to 1.5: 1, preferably 0, for Al / Li. 8: 1 to 1: 1.
  • retarder metals other than Al and initiator metals other than Li are expediently stated as the molar ratio of retarder metal (for example Al, Mg or Zn) to initiator metal (for example Li) and is 0.5: 1 to 1.5: 1, preferably 0, for Al / Li. 8: 1 to 1: 1.
  • retarder metals other than Al and initiator metals other than Li for example by ripening the mixture.
  • a retarder is added to the rubber solution before the styrene monomer is added, in order to prevent the premature polymerization of the styrene monomers.
  • Suitable retarders are the retarder compounds already mentioned, in particular TEA or TIBA. It is preferred to add 0.001 to 2, in particular 0.01 to 1, mol% of the retarder, based on the styrene monomers.
  • This retarder additive changes the molar ratio retarder / initiator such that the reaction rate drops to almost zero.
  • the living polymer chains are "dormant", i.e. the reaction is "frozen” but not stopped. By adding initiator again for re-initiation, the molar ratio changes again and the stopped reaction starts again, it “thaws”.
  • step b) If the polymerization in step b) is not anionic but free-radical, the polymerization is initiated either thermally or the usual free-radical polymerization initiators (in short: free-radical initiators), in particular peroxidic initiators, are used for this.
  • free-radical initiators in particular peroxidic initiators
  • An organic peroxide is preferably used which has a half-life of about 5 to 30 minutes at the respective reaction temperature. You can use alkyl or acyl peroxides, hydroperoxides, peresters or peroxy carbonates.
  • a graft-active initiator such as dibenzoyl peroxide, t-butylperoxy-2-ethylhexanoate, t-butylperbenzoate, 1,1-di- (t-butylperoxy) cyclohexane or 1,1-di- (t-butylperoxy) -3 is preferably used , 3,5-trimethylcyclohexane.
  • the radical initiator can be used as such or as a solution in an inert solvent, e.g. Toluene.
  • the amount of free-radical initiators required depends, inter alia, on the desired molecular weight (molar mass) of the polymer to be prepared and on the polymerization temperature. As a rule, 20 to 1000 are used, in particular re 50 to 500 ppmw (parts per million by weight), based on the total amount of styrene monomers used in steps a) and b).
  • the polymerization in step b) is preferably carried out in the absence or — less preferably — in the presence of a solvent.
  • Suitable solvents are, for example, aliphatic, isocyclic or aromatic hydrocarbons or hydrocarbon mixtures, such as benzene, toluene, ethylbenzene, xylene, cumene, hexane, heptane, octane or cyclohexane. If solvents are used, those with a boiling point above 95 ° C, e.g. Toluene, preferred. The solvent is usually removed during degassing, then collected by condensation and reused after cleaning.
  • the polymerization reaction is terminated by adding a chain terminator which irreversibly terminates the living polymer chain ends.
  • chain terminator All proton-active substances and Lewis acids can be considered as chain terminators.
  • water (preferred) and CrCio alcohols such as methanol, ethanol, isopropanol, n-propanol and the butanols are suitable.
  • Aliphatic and aromatic carboxylic acids such as 2-ethylhexanoic acid and phenols are also suitable.
  • Inorganic acids such as carbonic acid (solution of CO 2 in water) and boric acid can also be used.
  • the reaction mixture is usually worked up, for example by means of degassing.
  • the desired impact-resistant polystyrene contains, for example, the auxiliaries and accompanying substances used in the polymerization and demolition, and, if appropriate, unreacted monomers (so-called residual monomers), and, if appropriate, oligomers or low molecular weight polymers as undesired by-products of the polymerization.
  • the degassing for example by means of conventional degassing devices such as degassing extruders, partial evaporators, continuous degassers or vacuum pots, removes residual monomers and oligomers and in particular the solvent ⁇ -methylstyrene.
  • reaction mixtures (polymer solutions) with very high solids contents of over 80% by weight can be produced.
  • the high solids content simplifies the degassing, reduces the time and cost of reprocessing, increases the product output and thus makes the product cheaper.
  • Step b) of the process can be carried out batchwise or continuously in any pressure- and temperature-resistant reactor, as has already been described in step a). Polymerization is usually carried out in step b) at 50 to 200, preferably 75 to 175 and particularly preferably 80 to 160 ° C. The information on step a) applies to the pressure and duration of the polymerization.
  • the polymerization can be carried out in one or more stages. In a preferred embodiment, at least one stage is carried out in a tower reactor or tubular reactor.
  • the rubber solution in step a) of the process, can be prepared batchwise, retarders may be added to prevent premature polymerization, and then styrene as a further styrene monomer can be added in step b).
  • a solution of the rubber is obtained in a mixture of ⁇ -methylstyrene (solvent from step a)) and styrene (styrene monomer from step b)).
  • the solution can be temporarily stored in a buffer tank and then continuously anionically polymerized with the addition of a further initiator composition.
  • the reaction mixture obtained in step b) has a solids content (FG) of at least 70, particularly preferably at least 80% by weight after the end of the polymerization.
  • Impact-resistant polystyrene is obtained as the end product of the process according to the invention.
  • the invention also relates to the impact-resistant polystyrene (HIPS) obtainable by the polymerization process.
  • HIPS impact-resistant polystyrene
  • the impact-resistant polystyrene contains polybutadiene or styrene-butadiene copolymers as the rubber.
  • Impact-resistant polystyrenes containing as rubber are particularly preferred according to the invention
  • styrene-butadiene two-block copolymer Si with a styrene content of 1 to 60, preferably 5 to 50% by weight, based on the two-block copolymer, or
  • styrene-butadiene-styrene triblock copolymer SBS with a styrene content of 1 to 60, preferably 5 to 50 wt .-%, based on the triblock copolymer.
  • SBS styrene-butadiene-styrene triblock copolymer
  • Mw weight average molecular weight
  • the butadiene block B has an Mw of 30,000 to 300,000, preferably 50,000 to 200,000
  • the styrene block S 2 has an Mw of 1,000 to 100,000, preferably 5,000 to 30,000, or
  • copolymers b) to e) can each contain up to 10, preferably up to 5% by weight of ⁇ -methylstyrene, in particular in their styrene blocks.
  • the hard matrix of the impact-resistant polystyrene consists of a styrene- ⁇ -methylstyrene copolymer. That Part of the solvent used in rubber synthesis, ⁇ -methylstyrene, is incorporated into the hard matrix as a comonomer in HIPS synthesis.
  • Hard matrix 10 to 90 in particular 20 to 60 wt .-%, based on the hard matrix.
  • the weight average molecular weight Mw of the hard matrix is e.g. 50,000 to 300,000, preferably 100,000 to 250,000 g / mol.
  • a mineral oil e.g. White oil
  • a mineral oil e.g. 0.1 to 10
  • a 0.5 to 5 wt .-% added, whereby the mechanical properties are improved, in particular the elongation at break increases.
  • an antioxidant or a stabilizer against exposure to light is used as a further additive in amounts of, for example, 0.01 to 0.3, preferably 0.02 to 0.2, by weight. -% used.
  • light stabilizer a stabilizer against exposure to light
  • these additives increase the resistance of the polymer to air and oxygen, or to UV radiation, and thus increase the weathering and aging resistance of the polymer.
  • the amounts given relate to the polymer obtained.
  • the polymers can contain other additives or processing aids, for example lubricants or degreasers. Molding agents, colorants such as pigments or dyes, flame retardants, fibrous and powdery fillers or reinforcing agents or antistatic agents, as well as other additives or their mixtures.
  • the individual additives are used in the usual amounts, so that further details are not necessary.
  • the additives can be added, for example, during the processing of the polymer melt, and / or the solid polymer (for example polymer granules) by mixing processes known per se, for example by melting in an extruder, Banbury mixer, kneader, roller mill or calender.
  • Shaped articles including semifinished products, films, fibers and foams of all kinds can be produced from the impact-resistant polystyrenes according to the invention.
  • the invention accordingly also relates to the use of the impact-resistant polystyrene according to the invention for the production of moldings, films, fibers and foams, and to the moldings, films, fibers and foams obtainable from the impact-resistant polystyrene.
  • the process according to the invention manages without inert solvents and has improved economy.
  • polymer solutions with high solids contents of over 80% by weight can be produced, which considerably reduces the time and cost of degassing.
  • the rubber solution obtained had a solids content (FG) of x9% by weight.
  • FG solids content
  • GPC analysis gel permeation chromatography in tetrahydrofuran, calibration with polybutadiene standards
  • the polymer had a monomodal distribution.
  • the residual monomer content of butadiene determined by gas chromatography was less than 10 ppm (w).
  • the weight average molecular weight Mw was determined by GPC as described above and was x10 kg / mol.
  • Table 1 summarizes the individual values of the variables x1 to x10.
  • Table 1 Rubber production: Variables x1 to x10 (FG solids content)
  • the polymerization was carried out continuously in a double-walled 50 l stirred kettle with a standard anchor stirrer.
  • the reactor was designed for an absolute pressure of 25 bar and was tempered with a heat transfer medium and by means of evaporative cooling for isothermal reaction control.
  • X13 kg / h of styrene, x14 kg / h of the rubber solution (see item 2 and Table 1 above) and x15 g / h of the initiator solution (initiator solution see item 1) were metered into the stirred kettle continuously at 115 rpm and the kettle kept at a constant reactor wall temperature of 130 to 140 ° C.
  • the solids content was x16% by weight;
  • the reaction mixture was then metered in x17 kg / h of styrene.
  • the reaction mixture was conveyed in a stirred 29 l tower reactor which was provided with two heating zones of the same size, the first zone being kept at x18 ° C. and the second zone x19 ° C. reactor wall temperature.
  • the solids content at the outlet of the tower reactor was x20% by weight.
  • the discharge from the tower reactor was mixed with x21 g / h of water, then passed through a mixer and finally passed through a pipe section heated to 250 ° C. Afterwards, the reaction mixture was degassed into a pressure control valve Pumped at x22 ° C operated partial evaporator and relaxed in a vacuum pot operated at 10 mbar absolute pressure and x23 ° C. The ⁇ -methylstyrene solvent removed in the degassing was condensed and reused after distillation.
  • the polymer melt obtained was discharged using a screw conveyor and then mixed with x24 g / h of an additive mixture of x25 g Irganox® 1076 and x26 g mineral oil Winog®70, passed through a mixer and granulated. The turnover was quantitative.
  • the HIPS obtained had the following residual monomer contents, which were determined as already described: styrene less than 5 ppm (w), ethylbenzene less than 5 ppm (w).
  • Table 2 summarizes the individual values of the variables x11 to x26.
  • Example HIPS3 The procedure was as described in Example HIPS3, with the following differences: I) a tubular reactor was used instead of the tower reactor.
  • the tubular reactor had a volume of 20 l, a diameter D of 50 mm and three heating zones with the following temperatures and volumes: first zone 130 ° C. and 6 l, second zone 140 ° C. and 6 l, third zone 160 ° C. and 8 l .
  • x17 4 kg / h of styrene (instead of 8 kg / h) were metered in at the outlet of the stirred tank, and
  • the solids content at the discharge from the tubular reactor (corresponds to variable x20) was 92.1% by weight.
  • butadiene rubbers can be produced with the process according to the invention without the use of inert solvents such as toluene or cyclohexane.
  • the rubber solutions obtained could be used directly for the production of impact-resistant polystyrene.
  • the HIPS solutions obtained had very high solids contents of well over 80% by weight; through process optimization (example HIPS4) even solids contents of over 90% could be achieved.
  • the high solids content made the degassing considerably easier and the economy of the process improved.

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  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Graft Or Block Polymers (AREA)

Abstract

L'invention concerne un procédé pour produire du polystyrène résilient à partir de diènes monomères et de monomères de styrène par polymérisation anionique ou anionique et radicalaire. L'invention est caractérisée en ce qu'on réalise d'abord une solution de caoutchouc par polymérisation anionique à partir de diènes monomères ou de diènes monomères et de monomères de styrène en présence d'un solvant et d'une composition d'amorce, cette polymérisation étant effectuée à au moins 20 °C et le seul solvant utilisé étant du alpha-méthylstyrène, puis on ajoute à cette solution de caoutchouc un monomère de styrène et on procède à la polymérisation anionique ou radicalaire de ce mélange en présence d'une composition d'amorce pour obtenir un polystyrène résilient.
EP04790620A 2003-10-30 2004-10-19 Procede de polymerisation anionique de monomeres en alpha-methylstyrene Withdrawn EP1682592A1 (fr)

Applications Claiming Priority (2)

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DE2003150998 DE10350998A1 (de) 2003-10-30 2003-10-30 Verfahren zur anionischen Polymerisation von Monomeren in α-Methylstyrol
PCT/EP2004/011796 WO2005047353A1 (fr) 2003-10-30 2004-10-19 Procede de polymerisation anionique de monomeres en alpha-methylstyrene

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US7212110B1 (en) 2004-04-19 2007-05-01 Advanced Neuromodulation Systems, Inc. Implantable device and system and method for wireless communication
ES2392100T3 (es) 2005-06-15 2012-12-04 Nippon Soda Co., Ltd. Polímero de ácido acrílico
CN101421350B (zh) 2006-03-24 2012-02-15 科腾聚合物美国有限责任公司 高温嵌段共聚物及其制备方法
ITMI20072324A1 (it) 2007-12-12 2009-06-13 Polimeri Europa Spa Procedimento semi-continuo integrato per la produzione di (co)polimeri vinilaromatici antiurto mediante polimerizzazione in sequenza anionica/radicalica

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GB1025573A (en) * 1962-12-24 1966-04-14 Foster Grant Co Inc Improvements in or relating to polymer processes and compositions
DE1770392B2 (de) * 1968-05-11 1980-07-03 Basf Ag, 6700 Ludwigshafen Verfahren zur Herstellung von schlagfesten kautschukhaltigen Polymerisaten
BE792704A (nl) * 1972-01-21 1973-06-14 Shell Int Research Werkwijze ter bereiding van een polymeer uit een geconjugeerd dieen door polymerisatie in oplossing met trihydrocarbylborium in hetkatalysatorsysteem
FR2295972A1 (fr) * 1974-12-23 1976-07-23 Michelin & Cie Polymerisation ou copolymerisation en solution d'un ou plusieurs dienes conjugues avec eventuellement un ou plusieurs composes vinylaromatiques
US4362849A (en) * 1979-07-18 1982-12-07 The Dow Chemical Company Preparation of alkenyl aromatic monomer butadiene rubber and preparation of impact resistant resin therefrom
US6444762B1 (en) * 1996-08-19 2002-09-03 Basf Aktiengesellschaft Anionic polymerization process
DE19731419A1 (de) * 1997-07-22 1999-01-28 Basf Ag Verfahren zur anionischen Polymerisation
DE59702613D1 (de) * 1996-08-19 2000-12-14 Basf Ag Verfahren zur herstellung von dienpolymerisatlösungen in vinylaromatischen monomeren
WO1999040135A1 (fr) * 1998-02-07 1999-08-12 Basf Aktiengesellschaft Procede de production de matieres de moulage thermoplastiques modifiees a resistance elevee aux chocs
DE19936566A1 (de) * 1999-08-04 2001-02-08 Basf Ag Verfahren zum Herstellen einer Lösung von Dienpolymerisaten in vinylaromatischen Verbindungen sowie zum Herstellen von schlagzähen vinylaromatischen Polymeren durch Polymerisation dieser Lösung
DE19954818A1 (de) * 1999-11-13 2001-05-17 Basf Ag Verfahren zur anionischen Polymerisation von vinylaromatischen Monomeren

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WO2005047353A1 (fr) 2005-05-26

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