EP1187862A1

EP1187862A1 - Method for producing thermoplastic molding materials using rubber solutions

Info

Publication number: EP1187862A1
Application number: EP00929500A
Authority: EP
Inventors: Gisbert Michels; Heike Windisch; Peter Krüger; Pierre Vanhoorne; Heinz-Dieter Brandt
Original assignee: Bayer AG
Current assignee: Bayer AG
Priority date: 1999-05-18
Filing date: 2000-05-05
Publication date: 2002-03-20
Also published as: RU2001134206A; BR0010762A; CA2372178A1; MXPA01011759A; JP2002544350A; AU4755400A; CN1350560A; WO2000069940A1

Abstract

The invention relates to a method for producing ABS and HIPS molding materials. According to this method, a solution containing rubber is produced first and the polymerization for producing the ABS and HIPS molding materials is then carried out in the presence of this solution containing rubber. The solution containing rubber is produced by polymerizing diolefines in a solution of vinyl aromatic monomers, in the presence of a catalyst containing the following: (A) at least one compound of the rare earth metals; (B) optionally, a cyclopentadine; and (C) at least one organo-aluminium compound.

Description

Process for the production of thermoplastic molding compositions using rubber solutions

The present invention relates to a process for the production of ABS thermoplastics and impact-resistant polystyrenes (hereinafter referred to as HIPS = high impact polystyrene), wherein vinylaromatic-diolefin copolymers dissolved in vinylaromatic compounds and prepared as solvents by transition metal catalysts in vinylaromatic compounds statistical form can be used as rubbers.

Bulk and solution polymerization processes are known for the production of ABS molding compositions and are described in Houben-Weyl, Methods of Organic Chemistry, Volume E20 / Part 1, pp. 182-217, Georg Thieme Verlag Stuttgart. The manufacture of HIPS is also known and e.g. in Becker / Braun, plastic manual, volume 4 "Polystyrene" p. 109-120, ISBN 3-446-18004-4, 1996, Carl Hanser

Verlag and "Styrene Polymers", Encyclopedia of Polymer Science and Engineering, Vol. 16, pp. 1-246, 2 " ^d Ed., 1989, John Wiley + Sons. These processes involve the dissolution of rubbers in vinyl aromatic monomers ( eg styrene) and ethylenically unsaturated nitrile monomers (eg acrylonitrile) and, where appropriate, solvents and the polymerization of the monomers

Polymerization occurs a phase separation between the rubber-containing polymer solution and the non-rubber-containing polymer solution. The non-rubber-containing polymer solution initially forms a discrete, discontinuous phase. With increasing monomer conversion, phase inversion takes place, i.e. the phase of the non-rubber-containing polymer solution becomes larger and the rubber solution becomes the discontinuous phase, while the non-rubber-containing polymer solution forms the homogeneous phase.

To produce ABS and HIPS molding compositions, the rubber solutions prepared by dissolving are in the presence of further monomers and, if appropriate, solvents by known methods of bulk, solvent or Suspension polymerization prepared in a continuous, semi-continuous or batch mode and isolated by known evaporation methods.

A disadvantage of many processes for the production of ABS and HIPS by the bulk, solution or suspension process is that soluble rubbers in solid

Form are used, which are dissolved in styrene and / or further monomers and optionally solvents and then fed to the further polymerization process as a rubber solution. To dissolve the solid rubbers, they have to be cut into small pieces and dissolved in a dissolving container in styrene and / or other monomers and, if appropriate, solvents.

The use of rubbers in solid form is disadvantageous because the production of these soluble rubbers is preferably carried out by solution polymerization, aliphatic and / or aromatic solvents being used as solvents which are inert during the polymerization and which themselves are not polymerization-active, and the solvents may have to be removed by distillation after the polymerization in order to isolate the rubbers formed in solid form. Another disadvantage is that rubbers with high cold flow or high stickiness are difficult to process and store.

Attempts have already been made to produce vinylaromatic-diolefin copolymers in vinylaromatic compounds as solvents and to use these rubber solutions for the production of ABS and HIPS molding compositions.

In US-A 431 1819 anionic initiators such as e.g. Butyllithium, used for the polymerization of butadiene in styrene. According to the patent examples, an SBR rubber suitable for HIPS production could be obtained by terminating the polymerization either at an initial butadiene in styrene concentration of about 35% by weight, the polymerization being stopped at a butadiene monomer conversion of about 25%, or by increasing the monomer conversion of butadiene to approximately by a high butadiene concentration of approximately 55% by weight

36% was increased, so that the majority of the butadiene used before one further use of the styrenic rubber solution for impact modification must be separated by distillation.

The disadvantage of the anionic initiators is that styrene-butadiene copolymers (SBR) are formed which, based on the butadiene units, allow only a slight control of the microstructure. By adding modifiers, only the proportion of 1, 2 or 1, 4-trans units can be increased, which leads to an increase in the glass transition temperature of the polymer. It is not possible to produce a high-cis-containing SBR with anionic initiators, in which the 1,4-cis content, based on the butadiene content, is over 40%, preferably over 50%, particularly preferably over 60%. This fact is disadvantageous above all because SBR is formed in this process, which results in a further increase in the glass transition temperature with increasing styrene content compared to homopolymeric polybutadiene (BR). However, when the rubber is used to modify the impact resistance of, for example, HIPS or ABS, a high glass transition temperature has an effect

Rubber adversely affects the low temperature properties of the material, so that rubbers with low glass transition temperatures are preferred.

In US-A 3299178 a catalyst system based on TiCl t / iodine / Al (isobu) 3, for the polymerization of butadiene in styrene to form homogeneous

Polybutadiene claimed. However, the same catalyst system is used in more recent literature by Harwart et al. in Plaste and Kautschuk, 24/8 (1977) 540 describes the copolymerization of butadiene and styrene and, on the other hand, the suitability of the catalyst for the production of polystyrene. This makes this catalyst system unsuitable for the production of vinylaromatic-diolefin copolymers in vinylaromatic solvents.

US-A 5096970 and EP-A 304088 describe a process for the preparation of polybutadiene in styrene using catalysts based on neodymium phosphonates, organic aluminum compounds such as di (isobutyl) aluminum hydride (DIBAH). and a halogen-containing Lewis acid, such as ethyl aluminum sesquichloride, described in which butadiene in styrene is converted to a 1,4-cis-polybutadiene without the addition of inert solvents. A disadvantage of this catalyst is that the rubbers obtained have a very low 1,2-unit content of less than 1%. It is disadvantageous because a higher 1, 2 content in the rubber has a positive effect on the grafting behavior between the rubber and the polymer matrix, for example homo- or copolymers of vinylaromatic compounds.

Kobayashi et al. was e.g. in J. Polym. Be., Part A, Polym. Chem., 33 (1995) 21 75 and 36 (1998) 241 a catalyst system consisting of halogenated rare earth acetates, e.g. Nd (OCOCCl3) 3 or Gd (OCOCF3) 3, described with tri (isobutyl) aluminum and diethyl aluminum chloride, which enables the copolymerization of butadiene and styrene in the inert solvent hexane. A disadvantage of these catalysts, in addition to the presence of inert solvents, is that the catalyst activity drops to below 10 g of polymer / mmol of catalyst / h even with a small amount of styrene incorporated, and that the 1,4-cis content of the polymer is based on the polymeric butadiene units decreases significantly with increasing styrene content.

The rubber solutions in styrene described in the listed patent publications were used for the production of HIPS by adding free-radical initiators to the rubber solutions in styrene after removal of the unreacted butadiene monomer.

On the other hand, for the production of ABS, the rubber is in a matrix of

Acrylonitrile-styrene copolymers (SAN) are used. In contrast to the production of HIPS, the SAN matrix in ABS is incompatible with polystyrene. If, during the polymerization of the diolefins in vinylaromatic solvents, homopolymers of the solvent, such as polystyrene, are formed in addition to the rubber, the incompatibility of the SAN matrix with the homopoly- merized vinyl aromatics to a significant deterioration in the material properties.

WO 97/38031 and WO 98/07766 describe that styrene-butadiene copolymers or polybutadiene homopolymers are prepared anionically in solution in the presence of inert solvents and for the production of toughened, thermoplastic polystyrene molding compounds and polystyrene-acrylonitrile molding compounds be used. It is disadvantageous that inert solvents are added in the butadiene polymerization, so that the vapors obtained after the degassing, which contain unreacted monomers and solvents, have to be separated and dried in a complex manner in order to reuse them in an anionic polymerization.

The invention has for its object to develop a process for the production of ABS and HIPS molding compositions by polymerization in rubber-containing solution, which does not meet the above when using suitable catalysts. Has disadvantages and also makes it possible to vary the proportion of styrene units in the dissolved rubber.

Furthermore, it should allow the rubber solution used to be used directly, i.e. can be used for the production of ABS and HIPS molding compounds without isolating and redissolving the rubber in vinyl aromatic compounds.

The solution to this problem is that for the preparation of the rubber-containing solution containing diolefins in a solution of vinyl aromatic monomers in the presence of a catalyst

(A) at least one compound of the rare earth metals,

(B) optionally at least one cyclopentadiene and (C) at least one organoaluminum compound,

be polymerized.

Surprisingly, it was found that the process according to the invention can be carried out without the addition of inert solvents.

The rubber solutions to be used are obtained by polymerizing conjugated diolefins in vinyl aromatic solvents. In doing so

Copolymers formed in which the polymer composition based on the content of vinyl aromatics and diolefins and the selectivity of the polymerized diolefins, such as e.g. the content of cis double bonds and of 1, 2 units with pendant vinyl groups can be varied, the glass transition temperature of the polymer being below -60 ° C., preferably below -70 ° C.

The rubber solutions to be used are obtained by polymerizing the diolefins in the presence of catalysts based on rare earth metal compounds and in the presence of vinylaromatic monomers as solvents at temperatures from -30 to 100 ° C., preferably at

Temperatures from -20 to 90 ° C, particularly preferably at temperatures from 20 to 80 ° C by known methods in a continuous, semi-continuous or batch mode.

As conjugated diolefins e.g. 1,3-butadiene, 1,3-isoprene, 2,3-dimethyl-butadiene, 2,4-hexadiene, 1,3-pentadiene and / or 2-methyl-1,3-pentadiene or mixtures of the monomers mentioned can be used , 1,3-butadiene is preferred.

Of course, it is also possible, in addition to the conjugated diolefins, to use other unsaturated compounds, such as ethylene, propene, 1-butene, 1-pentene, 1- Hexene, 1-octene and / or cyclopentene preferably use ethylene, propene, 1-butene, 1-hexene, and or 1-octene, which can be copolymerized with the diolefins mentioned.

The molar ratio of the catalyst components (A) :( B) :( C) can be in the range from 1: 0.01 to 1.99: 0.1 to 1000. Component (A) of the catalyst can be used in amounts of 1 μmol to 10 mmol, based on 100 g of the conjugated diolefins, and the aromatic vinyl compound in amounts of 50 g to 2,000 g, based on 100 g of the conjugated diolefins used become.

The molar ratio of components (A) :( B) :( C) in the catalyst used is in the range from 1: 0.1 to 1.9: 3 to 500, particularly preferably 1: 0.2 to 1.8: 5 to 100.

Suitable compounds of the rare earth metals (component (A)) are, in particular, those which are selected from

an alcoholate of the rare earth metals, - a phosphonate, phosphinates and / or phosphates of the rare earth metals, a carboxylate of the rare earth metals, a complex compound of the rare earth metals with diketones and / or an addition compound of the halides of the rare earth metals with a

Oxygen or nitrogen donor compound.

The aforementioned compounds of rare earth metals are described in more detail, for example, in EP-A 1 1 184.

The compounds of rare earth metals are based in particular on the elements with atomic numbers 21, 39 and 57 to 71. Lanthanum, praseodymium or neodymium or a mixture of elements are preferably used as rare earth metals. ten of the rare earth metals, which contains at least one of the elements lanthanum, praseodymium or neodymium to at least 10 wt .-%. Lanthanum or neodymium are very particularly preferably used as rare earth metals, which in turn can be mixed with other rare earth metals. The proportion of lanthanum and / or neodymium in such a mixture is particularly preferably at least 30% by weight.

Suitable alcoholates, phosphonates, phosphinates, phosphates and carboxylates of the rare earth metals or as complex compounds of the rare earth metals with diketones are, in particular, those in which the organic group contained in the compounds in particular straight-chain or branched alkyl radicals having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms, such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, isopropyl, isobutyl, tert-butyl, 2-ethylhexyl, neo-pentyl, neo-octyl, neo-decyl or neo-dodecyl .

Rare earth alcoholates e.g. called:

Neodymium (III) -n-propanolate, neodymium (III) -n-butanolate, neodymium (III) -n-decanolate, neodymium (III) -isopropanolate, neodymium (III) -2-ethylhexanolate, praseodymium (III) -n-propanolate, praseodymium (III) -n-butanolate, praseodymium (III) -n-decanolate, praseodymium (III) -isopropanolate, praseodymium (III) -2-ethylhexanolate, lanthanum ( III) -n-propanolate, lanthanum (III) -n-butanolate, lanthanum (III) -n-decanolate, lanthanum (III) -isopropanolate, lanthanum (III) -2-ethyl-hexanolate are preferred Neodymium (III) -n-butanolate, neodymium (III) -n-decanolate, neodymium (III) -2-ethyl-hexanolate.

As the phosphonates, phosphinates and rare earth phosphates, e.g. called:

Neodymium (III) -dibutylphosphonate, neodymium (III) -dipcntylphosphonate, neodymium (IIl) -di- hexylphosphonate, neodymium (III) -diheptylphosphonate. Neodymium (ll) dioctylphosphonate,

Neodymium (III) dinonylphosphonate, neodymium (III) didodecylphosphonate, neodymium (III) - dibutylphosphinate, neodymium (III) -dipentylphosphinate, neodymium (III) -dihexylphosphinate, neodymium (III) -diheptylphosphinate, neodymium (III) -dioctylphosphinate, neodymium (IΙI) -dinonylphosphinate-neodidym (III) III) - dioctylphosphonate and neodymium (III) dioctylphosphinate.

Suitable carboxylates of rare earth metals are:

Lanthanum (III) propionate, lanthanum (III) diethyl acetate, lanthanum (III) -2-ethylhexanoate, lanthanum (III) stearate, lanthanum (III) benzoate, lanthanum (III) cyclohexane carboxylate, lanethane (III ) oleate, lanthanum (III) versatate, lanthanum (III) naphthenate, praseodymium (III) propionate, praseodymium (III) diethyl acetate, praseodymium (III) -2-ethylhexanoate, praseodymium (III) stearate, Praseodymium (III) benzoate, praseodymium (III) cyclohexane carboxylate, praseodymium (III) oleate, praseodymium (III) versatate, praseodymium (III) naphthenate, neodymium (IΙI) propionate, neodymium (III) diethylacetate, Neodymium (III) -2-ethylhexanoate, neodymium (IΙI) stearate, neodymium (III) benzoate, neodymium (III) cyclohexane carboxylate, neodymium (III) oleate, neodymium (III) versatate, neodymium (III) - naphthenate, preferably neodymium (III) -2-ethylhexanoate, neodymium (III) versatate, neodymium (III) naphthenate. Neodymium versatate is particularly preferred.

The following are mentioned as complex compounds of rare earth metals with diketones:

Lanthanum (III) acetylacetonate, praseodymium (III) acetylacetonate, neodymium (III) acetyl acetonate, preferably neodymium (III) acetylacetonate.

Examples of addition compounds of the halides of rare earth metals with an oxygen or nitrogen donor compound are:

Lanthanum (III) chloride with tributyl phosphate, lanthanum (III) chloride with tetrahydrofuran,

Lanthanum (III) chloride with isopropanol, lanthanum (III) chloride with pyridine. Lanthanum (III) - chloride with 2-ethylhexanol. Lanthanum (III) chloride with ethanol, praseodymium (IIl) chloride with tributyl phosphate, praseodymium (III) chloride with tetrahydrofuran, praseodymium (III) - chloride with iso-propanol, praseodymium (III) chloride with pyridine, praseodymium (III) chloride with 2-ethylhexanol, praseodymium (III) chloride with ethanol, neodymium (III) chloride with tributyl phosphate, neodymium (III) chloride with tetrahydrofuran, neodymium (III) chloride with isopropanol, neodymium (I_I) chloride with pyridine, neodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with ethanol, lanthanum (III) - bromide with tributyl phosphate, lanthanum (III) bromide with tetrahydrofuran, lanthanum (III) bromide with isopropanol, lanthanum (III) bromide with pyridine, lanthanum (III) bromide with 2-ethylhexanol, lanthanum (III) bromide with ethanol, praseodymium (III) bromide with tributyl phosphate, praseodymium (III) bromide with tetrahydrofuran, praseodymium (III) bromide with isopropanol, praseodymium (HI) bromide with pyridine, praseodymium (III) bromide with 2-

Ethylhexanol, praseodymium (III) bromide with ethanol, neodymium (III) bromide with tributyl phosphate, neodymium (III) bromide with tetrahydrofuran, neodymium (III) bromide with isopropanol, neodymium (III) bromide with pyridine, neodymium (III) bromide with 2-ethylhexanol, neodymium (III) bromide with ethanol, preferably lanthanum (III) chloride with tributyl phosphate, lanthanum (III) chloride with pyridine, lanthanum (III) chloride with 2-

Ethylhexanol, praseodymium (III) chloride with tributyl phosphate, praseodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with tributylphosphate, neodymium (III) chloride with tetrahydrofuran, neodymium (III) chloride with 2-ethylhexanol , Neodymium (III) chloride with pyridine, neodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with ethanol.

Neodymium versatate, neodymium octanoate and / or neodymium naphthenate are very particularly preferably used as compounds of the rare earth metals.

The above-mentioned compounds of rare earth metals can be used both individually and in a mixture with one another.

As cyclopentadienes (component (B)), compounds of the formulas (I), (II) or (III)

(I) (II) (in)

used, in which R * to R ° are the same or different or are optionally connected to one another or are condensed on the cyclopentadiene of the formula (I), (II) or (III), and for hydrogen, a Ci - to C30-alkyl group, one Cβ to Cl O aryl group, a Cη to C40 alkylaryl group, a C3 to C30 silyl group, where the alkyl groups can either be saturated or mono- or polyunsaturated and can contain heteroatoms such as oxygen, nitrogen or halides . In particular, the radicals can represent hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, methylphenyl, cyclohexyl, benzyl, trimethylsilyl or triflourmethyl.

Examples of the cyclopentadienes are the unsubstituted cyclopentadiene, methyl cyclopentadiene, ethylcyclopentadiene, n-butylcyclopentadiene, tert-butylcyclopentadiene, vinyl cyclopentadiene, Benzylcyclopentadien, Phenylcyclopentadien, Trimefhyl- silylcyclopentadien, 2-Methoxyethylcyclopentadien, 1, 2-dimethylcyclopentadiene, 1, 3- Dimethylcyclopentadiene, trimethylcyclopentadiene, tetramethylcyclopentadiene, tetraphenylcyclopentadiene, tetrabenzylcyclopentadiene, pentamethylcyclopentadiene, pentabenzylcyclopentadiene, ethyl tetramethylcyclopentadiene, trifluoromethyl tetramethyl, methylamethyl, methylamethyl, methylamethylindenyl, methylamethylindenyl, methylamethylindenyl, methylamethylindenyl, methylamethylindenyl, methylamethylindenyl, methylphenyl, methylphenyl, methyl-2-enamethylene, 4-methyldiamine, methyl-2-enamyl, methyl-2-methylphenyl, methyl-2-enamyl, methyl-2-enamethyl, methyl-2-enamethyl, methyl-2-enamethyl, methyl-2-enamyl, methyl-2-enamethyl, methyl-2-enamethylene,

The cyclopentadienes can also be used individually or in a mixture with one another. Suitable organoaluminum compounds (component (C)) are, in particular, alumoxanes and / or aluminum organyl compounds.

Aluminum-oxygen compounds which, as is known to the person skilled in the art, are obtained as alumoxanes and are obtained by contacting organoaluminum compounds with condensing components, such as water, and the noncyclic or cyclic compounds of the formula (-Al (R) O- ) contain _n , where R can be the same or different and represents a linear or branched alkyl group having 1 to 10 carbon atoms, which can contain heteroatoms, such as oxygen or halogens, and n is determined by the degree of condensation.

In particular, R represents methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-octyl or iso-octyl, particularly preferably methyl, ethyl or iso-butyl. Examples of alumoxanes are: methylalumoxane, ethylalumoxane and isobutylalumoxane, preferably methylalumoxane and isobutylalumoxane.

Compounds of the formula AIR ¹⁰ 3_ < _j Xd are used as aluminum organyl compounds, where

R ^{10 can be the} same or different and can stand for a Ci - to C30-alkyl group, a Cß- to Cio-aryl group, a C7 to C40-alkylaryl group, whereby the alkyl groups can be either saturated or mono- or polyunsaturated and heteroatoms, such as may contain oxygen or nitrogen,

X represents a hydrogen or a halogen and

d represents a number from 0 to 2.

The organoaluminum compounds of the formula AlR ¹⁰ 3_ _c ιX _c } which can be used are, in particular: tmethylaluminum, tmethylaluminum, Tn-n-propylaluminum,

Tri-iso-propyl aluminum, Tπ-n-butyl aluminum, Tπ-iso-butyl aluminum, Tπpentyl- aluminum, ethylaluminiumhydrid trihexylaluminum, tricyclohexylaluminum, trioctylaluminum, di-, di-n-butylaluminum hydride, di-iso-butylaluminum hydride, Diethylaluminiumbutanolat, Diethylaluminiumethyliden (dimethyl) amine, and diethyl lauminiumimethyliden (methyl) ether, preferably trimethyl aluminum, Triethylalu- minium, tri-iso -butyl aluminum and di-iso-butyl aluminum hydride.

The organoaluminum compounds can in turn be used individually or as a mixture with one another.

It is also possible to add a further component (D) to the proven catalyst components (A) to (C). This component (D) can be a conjugated diene, which can be the same diene that is later to be polymerized with the catalyst. Butadiene and / or isoprene are preferably used.

If component (D) is added to the catalyst, the amount of (D) is preferably 1 to 1000 mol, based on 1 mol of component (A), particularly preferably 1 to 100 mol. 1 to 50 mol, based on 1 mol of component (A), of (D) are very particularly preferably used.

In the manufacture of the rubber solutions, the catalysts are used in quantities of

1 μmol to 10 mmol, preferably 10 μmol to 5 mmol, of the compound of the rare earth metals based on 100 g of the monomers.

Of course, it is also possible to use the catalysts in any mixture with one another.

The rubber solution is prepared in the presence of vinylaromatic monomers, in particular in the presence of styrene, α-methylstyrene, α-methylstyrene dimer, p-methylstyrene, divinylbenzene and / or other nucleus-substituted alkylstyrenes, preferably with 2 to 6 carbon atoms in the Alkyl radical performed. The preparation of the rubber solution in the presence of styrene, α-methylstyrene, α-methylstyrene dimer and / or p-methylstyrene as a solvent is very particularly preferably carried out.

The solvents can be used individually or in a mixture.

The amount of vinyl aromatic monomers used as solvent is usually 10 to 2,000 parts by weight, preferably 30 to 1,000 parts by weight, very particularly preferably 50 to 500 parts by weight, based on 100 parts by weight of the set monomers.

The rubber solutions are preferably produced at temperatures from -20 to 90 ° C., very particularly preferably at temperatures from 20 to 80 ° C. The production can be carried out without pressure or at elevated pressure (0.1 to 12 bar). The production can be carried out continuously or discontinuously, preferably in a continuous manner.

It is also possible to remove part of the solvent and / or the unreacted monomers after the polymerization, preferably by distillation, if appropriate under reduced pressure, in order to obtain the desired polymer concentration.

The rubber-modified thermoplastic molding compositions according to the invention are obtained by radical polymerization of a vinylaromatic monomer and an ethylenically unsaturated nitrile monomer or a vinylaromatic

Monomers in the presence of one of the rubber solutions described above with the addition of ethylenically unsaturated nitrile monomer and optionally with the addition of further vinyl aromatic monomers and optionally in the presence of solvents by known bulk, solution or suspension polymerization processes in a continuous, semi-continuous or batch procedure . Styrene-butadiene copolymer solutions in styrene, which can be prepared as described above, are preferably used for the rubber-modified thermoplastic molding compositions according to the invention and in the process according to the invention for their preparation.

Rubber solutions are preferably used in which the dissolved styrene-butadiene copolymers have a styrene unit content of 5 to 40 mol%, particularly preferably 10 to 30 mol% and, based on the butadiene content, a 1,2-unit content, ie on pendant vinyl groups, from 2 to 20 mol%, particularly preferably 4 to 15 mol% and a content of 1,4-cis units from 35 to 85 mol%, particularly preferably from 45 to 85 mol% and the glass temperature is below -60 ° C, particularly preferably below -70 ° C.

Vinylaromatic monomers, which alone or optionally together with free-radically polymerized together with ethylenically unsaturated nitrile monomers and thereby form the homogeneous phase (matrix phase) of the molding compositions, are the same as those used to prepare the rubber solution. Core-substituted chlorostyrenes can also be used in a mixture with these.

Ethylenically unsaturated nitrile monomers are preferably acrylonitrile and methacrylonitrile, acrylonitrile is particularly preferred.

It is also possible to use up to 30% by weight, preferably up to 20% by weight, of the total monomer amount of acrylic monomers or maleic acid derivatives: such as, for example, methyl (meth) acrylate, ethyl (meth) acrylate, tert-butyl (meth) acrylate , Esters of fumaric acid, itaconic acid, maleic anhydride, maleic acid esters, N-substituted maleimides such as advantageously N-cycohexyl- or N-phenyl-maleimide, N-alkylphenyl-maleimide. further acrylic acid, methacrylic acid, fumaric acid, itaconic acid, or their amides. The ratio of vinyl aromatic monomers to ethylenically unsaturated nitrile monomers in the ABS molding compositions according to the invention is 60-90% by weight to 40-10% by weight, based on the matrix phase. The rubber content in the ABS molding compositions according to the invention is 5-35% by weight, preferably 8-25% by weight, based on the ABS molding composition.

The rubber content in the HIPS molding compositions according to the invention is 1 to 25% by weight, preferably 3 to 15% by weight, based on the HIPS molding compositions.

If the radical polymerization is carried out in solvents, aromatic hydrocarbons such as toluene, ethylbenzene, xylenes and ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone and mixtures of these solvents are suitable as solvents. Ethylbenzene, methyl ethyl ketone and acetone and mixtures thereof are preferred.

The polymerization is advantageously triggered by radical starters, but can also be carried out thermally; the molecular weight of the polymer formed can be adjusted by molecular weight regulators.

Suitable initiators for radical polymerization are graft-active, in

Radically disintegrating peroxides such as peroxycarbonates, peroxydicarbonates, diacyl peroxides, perketals, or dialkyl peroxides and / or azo compounds or mixtures thereof. Examples are azodiisobutyronitrile, azoisobutyric acid alkyl ester, tert-butyl perpivalate, tert-butyl peroctoate, tert-butyl perbenzoate, tert-butyl perneodecanoate, tert-butyl per- (2-ethylhexyl) carbonate. These initiators are used in amounts of 0.005 to 1% by weight, based on the monomers.

To adjust the molecular weights, conventional molecular weight regulators such as mercaptans, olefins, for example tert-dodecyl mercaptan, n-dodecyl mercaptan, cyclohexene, terpiπolen, α-methylstyrene dimer in amounts of 0.05 to 2% by weight, based on the monomers, can be used become. The process according to the invention can be carried out batchwise, semi-continuously and continuously. In the continuous embodiment, the rubber solution, monomers and, if appropriate, solvents can advantageously be polymerized in a continuously charged, mixed and stirred tank reactor with a stationary monomer conversion after the phase inversion in the first stage of more than 10%, and the radical-triggered polymerization in at least one continue in a further stage up to a monomer conversion of 30-90% with mixing in one or more continuously operated stirred kettles in cascade or in a mixing plug flow reactor and / or a combination of both types of reactor. Residual monomers and solvents can be removed using conventional techniques (e.g. in heat exchanger evaporators, flash evaporators, strand evaporators, thin-film or thin-film evaporators, screw evaporators, stirred multi-phase evaporators with kneading and stripping devices), the use of

Propellants and entraining agents, e.g. Water vapor, is possible, and can be returned to the process. During the polymerization and during the polymer insulation additives, stabilizers, anti-aging agents, fillers,

Lubricants can be added.

The discontinuous and semi-continuous polymerization can be carried out in one or more filled or partially filled stirred tanks connected in series with the rubber solution, monomers and, if appropriate, solvents and polymerization, up to the stated monomer conversion of 30-90%.

For better mixing and division of the rubber solution fed in, the syrup can be pumped in a circle over both mixing and shearing organs with continuous and discontinuous operation. Such loop reactors are state of the art and can be used when setting the

Particle size of the rubber may be helpful. However, the arrangement is more advantageous of shear organs between two separate reactors to avoid back-mixing, which leads to a broadening of the particle size distribution.

The average residence time is 1 to 10 hours, preferably 2 to 6 hours. The polymerization temperature is 50 to 180 ° C, preferably 70 to 170 ° C.

The rubber-modified thermoplastic molding compositions according to the invention have rubber particle sizes with a diameter (weight average, dw) of 0.1-10 μm, preferably 0.1-2 μm (ABS) or 0.1-10 μm, preferably 0.2- 6 μm (HIPS).

The molding compositions according to the invention can be processed themioplastically into molded parts by extrusion, injection molding, calendering, hollow body blowing, pressing and sintering.

Examples

Measurement methods

The solution viscosity of the rubber solutions is measured on a 5% strength by weight solution using a Brookfield viscometer at 25 ° C. (Brookfield RV, Syncro-Lectric, model LVT, spindle 2, speed can be set permanently, depending on viscosity: 6.12 , 30, 60 rpm).

SECTION:

The conversion is determined by solids determination by evaporation at 200 ° C. The rubber content in the end product was determined from the mass balance. Gel contents were determined in acetone as the dispersing medium. The Staudinger index of the soluble fraction was determined using dimethylformamide + lg / L LiCl as solvent. The particle size and distribution were determined by centrifugation as in US

5,166,261 described measured; in deviation from this, a dispersion of the rubber particles in propylene carbonate was injected into a mixture of propylene carbonate / acetone (75:25); the weight average (dw), the area average (dA) and the number average (d] \ [) are given. The notched impact strength (aκ-Izod) was determined at 23 ° C according to ISO 180 / 1A, the melt volume index (MVI 220 ° C / 10 kg)

Measured according to DIN 53735. The phase structure was examined by dynamic-mechanical measurement of the thrust module characteristics G * (T) at the NPS at a frequency of approx. 1 Hz in the temperature range from -150 to 200 ° C with the RDA II from Rheometrics. The glass transition temperature (Tg) of the soft phase and the matrix is determined. Furthermore, the corrected shear modulus at 23 ° C

(G 'orr _. (RT)) determined. The measured values were measured on injection molded articles at a melt temperature of 240 ° C and a mold temperature of 70 ° C. HIPS:

The impact strength (a _k , Izod) was determined at 23 ° C and -40 ° C according to ISO 180 / 1U, tensile strength, elongation at break, yield stress and modulus of elasticity according to DIN 53 455 and DIN 53 457. The measured values were measured on injection molded molds at a melt temperature of 200 ° C and a mold temperature of 45 ° C.

The melt volume index (MVI, 220 ° C, 5 kg) was determined according to DIN 53 735.

Manufacture of rubber solutions

The polymerizations were under the exclusion of air and moisture

Argon performed. The isolation of the polymers from the styrenic solution described in individual examples was carried out only for the purpose of characterizing the polymers obtained. The polymers can of course also be stored in the styrenic solution without insulation and processed further accordingly. The styrene used as solvent for the diene polymerization was stirred under argon over CaH2 at 25 ° C. for 24 h and distilled off at 25 ° C. under reduced pressure. The styrene content in the polymer is determined by means of H-NMR spectroscopy, the selectivity of the polybutadiene content (1,4-cis, 1,4-trans and 1,2-content) is determined by means of IR spectroscopy and the determination the molecular weights by means of GPC / light scattering.

Examples A-E

Catalyst aging A-C

In a 300 ml Schlenk flask at 25 ° C to 38.4 ml of a 0.3125 molar solution of neodymium (III) versatat (NDV) in hexane through a septum were 5.3 g butadiene, 1.88 ml pentamethylcyclopentadiene and 217 ml a 10% solution of methylalumoxane in toluene (MAO), heated to 50 ° C. for 2 hours with stirring and used for the polymerization. Catalyst aging DE

In a 300 ml Schlenk flask, 49.0 ml of a 0.245 molar solution of neodymium (III) versatate (NDV) in hexane were dissolved at 25 ° C. through a septum, 6.0 g of butadiene, 1.4 ml of indene and 217 ml of a 10th % solution of methylalumoxane in toluene

(MAO), heated to 50 ° C. for 2 hours with stirring and used for the polymerization.

Polymerization

The polymerization was carried out in a 40L steel reactor with anchor stirrer (50 rpm). At room temperature, a solution of trimethyl aluminum (TMA) or tri-iso-butyl aluminum (TIBA) in hexane was added to a solution of butadiene in styrene as a scavenger, the reaction solution was heated to 50 ° C. within 45 min and with the appropriate amount of catalyst solution transferred. During the

Polymerization, the reaction temperature was kept at 50 ° C. After the reaction time had expired, the polymer solution was transferred to a second reactor (80 L reactor, anchor stirrer, 50 rpm) within 15 minutes and the polymerization was carried out by adding 3,410 g of methyl ethyl ketone with 7.8 g of p-2,5-di-tert.- octyl butylphenol propionate (Irganox 1076, Ciba-Geigy) and 25.5 g of tris (nonylphenyl) phosphite (Irgafos TNPP, Ciba-Geigy). To remove unreacted butadiene, the internal reactor pressure at 50 ° C. was reduced to 200 mbar within 1 h and to 100 mbar within 2 h.

The batch sizes, reaction conditions and the properties of the obtained

Polymers are given in the table below.

a) 'Content of 1,4-cis, 1,4-trans and 1,2 units based on the butadiene content in

Polymers nb = not determined Manufacture of ABS molding compounds

Examples 1-7

In a 5L flat ground vessel with anchor stirrer and reflux condenser

Solution I, consisting of rubber solution, styrene, acrylonitrile, methyl ethyl ketone (MEK), p-2,5-di-tert-butylphenol-propionic acid octyl ester (Irganox 1076, Ciba Geigy) and alpha-methyl styrene dimer (AMSD), with 40 ° C mixed with an anchor stirrer (150 rpm). After heating this solution to 82-85 ° C, the starter solution II, consisting of methyl ethyl ketone and tert-butyl perpivalate (t-BPPIV), is metered in within 4 h. Throughout the reaction, the temperature is controlled so that there is a slight reflux (82-85 ° C). After 2 hours from the beginning of metering solution II, metering solution III, consisting of methyl ethyl ketone and alpha-methylstyrene dimer, is added in 1-2 minutes, then the stirrer is set to 100 rpm. After metering in of solution II, the mixture is stirred for a further 2 h at 85 ° C., then cooled to RT. For stabilization, a solution of octyl p-2,5-di-tert-butylphenol-propionate (Irganox 1076, Ciba Geigy) and dilauryl dithio-propionate (Irganox PS 800, Ciba Geigy) in methyl ethyl ketone is added. The solutions are then evaporated and granulated on a ZSK laboratory evaporation screw. The granules were hosed down into standard small bars.

The compositions of the formulations, results of the polymerization and characterization of the ABS molding compositions are summarized in the tables below. Composition of the recipes (all data in g)

Results:

Characterization of the ABS molding compounds

Production of HIPS molding compounds:

Example 8

The rubber solution from Example E is diluted to 6% solids by adding styrene (stabilized). After adding 0.5 parts by weight of Vulkanox MB ^y and 0.2 parts by weight Parts of α-methylstyrene dimers, 1 200 g of this solution are flushed with N ₂ in a 2 l glass autoclave with a spiral stirrer for 15 minutes. The mixture is heated to 120 ° C. within 1 hour and stirred at this temperature for 4.5 hours (80 rpm). The highly viscous solution obtained is filled into pressure-proof aluminum molds and polymerized according to the following time / temperature program:

2.5 h at 125 ° C 1.5 h at 135 ° C

1.5 h at 145 ° C 1.5 h at 165 ° C 2.5 h at 225 ° C.

After cooling, the polymer is crushed and 20 hours at 100 ° C in

Vacuum degassed. For testing, the samples are sprayed on an injection molding machine. The mechanical values are determined on standard small bars.

Results:

Claims

claims

1. Process for the production of ABS and HIPS molding compositions, in which

I. a rubber-containing solution is first prepared and

II. The polymerization for the production of the ABS and HIPS molding compositions is then carried out in the presence of this rubber-containing solution,

characterized in that for the preparation of the rubber-containing solution containing diolefins in a solution of vinyl aromatic monomers in the presence of a catalyst

(A) at least one compound of the rare earth metals,

(B) optionally at least one cyclopentadiene and

(C) at least one organoaluminum compound,

be polymerized.

2. A process for the preparation of ABS and HIPS molding compositions according to claim 1, characterized in that as vinyl aromatic monomers styrene, α-methylstyrene, α-methylstyrene dimer, p-methylstyrene, divinylbenzene, nucleus-substituted alkylstyrenes, preferably those with 2 to 6 Carbon atoms in the alkyl radical, or mixtures thereof.

3. A process for the preparation of ABS and HIPS form compositions according to claim 1 and 2, characterized in that as vinyl aromatic monomers Styrene, α-methylstyrene, α-methylstyrene dimer or mixtures thereof can be used.

4. A process for the production of ABS and HIPS molding compositions according to claim 1 to 3, characterized in that conjugated diolefins are used.

5. A process for the preparation of ABS and HIPS molding compositions according to claim 1 to 4, characterized in that 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, 2,4-hexadiene, 1,3-pentadiene as conjugated diolefins , 2-methyl-l, 3-pentadiene or mixtures thereof, particularly preferably 1,3-butadiene.

Process for the production of ABS and HIPS molding compositions according to Claims 1 to 5, characterized in that alcoholate, phosphonates, phosphinates, phosphates, carboxylates of the rare earth metals, complex compounds of the rare earth metals with diketones or addition compounds of the halides of the rare earths as catalyst component (A) Earth metals with oxygen or nitrogen donor compounds can be used.

Process for the preparation of ABS and HIPS foams according to Claim 1 to 6, characterized in that compounds of the formulas (I), (II) or (III) are used as the cyclopentadiene component (B)

(I) (II) (III) can be used in which R to R ° can be the same or different or can optionally be connected to one another or can be condensed on the cyclopentadiene of the formula (I), (II) or (III) and for hydrogen, a Cl to C30 alkyl group , a C6 to Cio aryl group, a C7 to C40 alkylaryl group or a C3 to C30 silyl group, where the alkyl groups can be either saturated or mono- or polyunsaturated and can contain heteroatoms such as oxygen, nitrogen or halides.

8. Process for the production of ABS and HIPS molding compositions according to Anspmch

1 to 7, characterized in that aluminum organanyl compounds, in particular alumoxanes, are used as organoaluminum component (C).

9. Process for the production of ABS and HIPS molding compositions according to Anspmch

1 to 8, characterized in that a conjugated diene is added to the catalyst components (A) to (C).

10. A process for the preparation of ABS and HIPS molding compositions according to Anspmch 1 to 9, characterized in that the molar ratio of the components

(A) to component (B) 1: 0.01 to 1: 1.99 and the molar ratio of component (A) to component (C) is 1: 0.1 to 1: 1000.

1 1. A method for producing ABS and HIPS molding compositions according to one of claims 1 to 10, characterized in that the rubber solution by

Polymerization of a diolefin is obtained without the addition of an inert solvent.

12. The method for producing ABS and HIPS molding compositions according to one or more of claims 1 to 1 1, characterized in that the process is carried out in a continuous or discontinuous procedure.

13. A process for the preparation of ABS and HIPS molding compositions according to Anspmch 1 to 12, characterized in that the production of the rubber solution is carried out at temperatures from -30 to 100 ° C.

14. A process for the production of ABS and HIPS molding compositions according to Claim 1 to 13, characterized in that the rubber solution is produced without dirt.

15. Process for the production of ABS and HIPS form masses according to Anspmch

1 to 14, characterized in that the rubber solution is produced at elevated pressure in the range 0.1 to 12 bar.

16. A process for the preparation of ABS and HIPS molding compositions according to Claim 1 to 15, characterized in that an unsaturated nitrile monomer, preferably acrylonitrile or methacrylonitrile, particularly preferably acrylonitrile, in the polymerization for producing the ABS molding compositions in the presence of the rubber-containing solution , are used.

17. Process for the production of ABS and HIPS molding compositions according to Anspmch

1 to 16, characterized in that up to 30%, based on the total amount of monomers, preferably up to 20%, of acrylic monomers or maleic acid derivatives are additionally used.

18. ABS and HIPS molding compositions, characterized in that they are obtainable by a process according to one or more of claims 1 to

17th

19. ABS and HIPS molding compositions according to Anspmch 18, characterized in that the styrene-butadiene copolymers used have a styrene unit content of 5 to 40 mol%, a 1,2-unit content based on Butadiene from 2 to 20 mol% and a content of 1, 4-cis units from 35 to 85 mol%.

20. ABS or HIPS molding compositions obtainable using styrene-butadiene copolymers which, based on the butadiene content, have a content of 35 to 85 mol% of cis-permanent double bonds.

21. Use of the ABS and HIPS molding compositions according to Anspmch 18 to 20 for the production of moldings and extrusion articles.

22. Moldings and extrusion articles, obtainable from ABS or HIPS molding compositions according to claims 1 to 20.