CN1351618A - Method for producing thermoplastic molding materials using rubber solutions - Google Patents

Abstract

The invention relates to a method for producing ABS molding materials. According to this method, a solution containing rubber is produced first and the polymerization for producing the ABS molding compounds is then carried out in the presence of this solution containing rubber. Said solution containing rubber is produced by polymerizing diolefines in a solution of vinylaromatic monomers, in the presence of a catalyst containing the following: (a) at least one compound of the rare earth metals; (b) at least one organo-aluminum compound; and (c) optionally, a Lewis acid.

Description

Process for producing thermoplastic molding compositions using rubber solutions

The present invention relates to a thermoplastic ABS molding composition and to a process for its production by polymerization in a rubber-containing solution, and to its use.

Bulk and solution polymerization processes for the production of ABS molding compositions are known and described, for example, in Houben-Weyl, Methoden der Organischen Chemie, Band 20/Teil 1, pp. 182-217, Georg Thieme Verlag, Stuttgart. These methods involve dissolving rubber in a vinyl aromatic monomer (such as styrene) and an ethylenically unsaturated nitrile monomer (such as acrylonitrile) and optionally solvent and polymerizing the monomers. During polymerization, a phase separation occurs between the rubber-containing polymer solution and the rubber-free polymer solution. The rubber-free polymer solution initially forms a discrete discontinuous phase. As the monomer conversion proceeds, phase inversion occurs, ie, the phase of the rubber-free polymer solution becomes larger and the rubber solution becomes a discontinuous phase, while the rubber-free polymer solution forms a homogeneous phase.

ABS molding compositions are polymerized in a continuous, semi-continuous or batch production process using known mass, solution or suspension polymerization methods using a rubber solution produced from dissolving solid rubber in the presence of other monomers and optionally a solvent produced and isolated using known evaporation methods.

The disadvantage of the known methods of producing ABS using bulk, solution or suspension methods is that the soluble rubber is used in solid form, where it is dissolved in styrene and/or other monomers and optionally solvents and then as a rubber solution is added to other processes in the aggregation method. To be able to dissolve, the solid rubber must be cut into small pieces and dissolved in styrene and/or other monomers and optionally solvent in a dissolution tank. The use of rubbers in solid form is disadvantageous because these soluble rubbers are preferably produced by solution polymerization methods in which aliphatic and/or aromatic solvents which are inert during the polymerization and not themselves reactive in the polymerization reaction are used as The solvent and where after the polymerization the solvent must optionally be removed by distillation in order to isolate the rubber formed in solid form. A further disadvantage is that rubbers with high cold flow or high viscosity are very difficult to process and store.

Attempts have already been made to produce diene polymers in vinyl aromatic compounds as solvents and to use these rubber solutions as intermediates.

In US 4,311,819 anionic initiators, such as butyllithium, are used to polymerize butadiene in styrene. According to the examples of this patent, it is possible to obtain SBR rubber suitable for HIPS production by terminating the polymerization reaction as early as about 25% or about 36% conversion of butadiene monomer. A disadvantage in this respect is that most of the introduced butadiene has to be separated by distillation before the solution of the rubber in styrene is subsequently used for impact modification.

Another disadvantage resides in the use of anionic initiators, since this forms styrene-butadiene copolymers (SBR), which are based on butadiene units and allow only slight control over the microstructure. By adding modifiers it is only possible to increase the proportion of 1,2 or 1,4-trans units, which leads to an increase in the glass transition temperature of the polymer. It is not possible to use anionic initiators to produce SBRs with a high cis content, where the 1,4-cis content, relative to the butadiene content, is higher than 40%, preferably higher than 50%, particularly preferably higher than 60% . A further disadvantage is the fact that in this process SBR is formed, and increasing the styrene content leads to a further increase in the glass transition temperature compared to the homopolymer polybutadiene (BR). However, if the rubber is used for impact modification such as HIPS or ABS, the increased glass transition temperature of the rubber has an adverse effect on the low temperature properties of the material, so rubbers with a low glass transition temperature are preferred.

US3299178 claims a _TiCl4 /iodine/Al(iso-Bu) ₃ based catalyst system for the polymerization of butadiene in styrene to form homogeneous polybutadiene. However, in more recent literature, Harwart et al., Plaste und Kautschuk, 24/8 (1977) 540, have described the copolymerization of butadiene and styrene using the same catalyst system and described the use of the catalyst for the production of polystyrene Suitability of styrene. This catalyst system is therefore not suitable for the production of diene polymers in vinyl aromatic solvents.

US 5096970 and EP 304088 describe the use of catalysts based on neodymium phosphonate, organoaluminum compounds such as di(isobutyl)aluminum hydride (DIBAH), and based on halogen-containing Lewis acids such as ethylaluminum trichloride in styrene Process for the production of polybutadiene by reacting butadiene in styrene without further addition of an inert solvent to obtain 1,4-cis polybutadiene. These rubber solutions are recommended for the production of impact-modified polystyrene (HIPS).

Kobayashi et al., J.Polym.Sci., Part A, Polym.Chem., 33(1995) 2175 and 36(1998) 241 have described catalyst systems consisting of haloacetic acid rare earth salts such as Nd(OCOCCl ₃ ) ₃ Or the composition of Gd(OCOCF ₃ ) ₃ with tri(isobutyl)aluminum and diethylaluminum chloride enables the copolymerization of butadiene and styrene in the inert solvent hexane. In addition to the presence of inert solvents, the disadvantages of these catalysts are that, with the incorporation of as low as about 5 mol% styrene, the catalyst activity decreases to less than 10 g polymer/mmol catalyst/hr and with increasing styrene content, relatively In terms of polymer butadiene units, the 1,4-cis content of the polymer is significantly reduced.

The rubber in styrene solution described in said patent publication has been used to produce HIPS by mixing the rubber in styrene solution with a free radical initiator after removal of unreacted butadiene monomer. accomplish.

On the other hand, this rubber is used in a matrix of acrylonitrile/styrene copolymer (SAN) to produce ABS. In contrast to the production of HIPS, the SAN matrix in ABS is not compatible with polystyrene. If dienes are polymerized in vinyl aromatic solvents together with rubber to form solvent homopolymers, such as polystyrene, the incompatibility between the SAN matrix and the homopolymerized vinyl aromatic hydrocarbons during the production of ABS Capacitance will result in a significant loss of material properties.

WO 97/38031 and WO 98/07766 describe thermoplastic polystyrene molding compositions and poly In the production of styrene/acrylonitrile molding compositions. A disadvantage is that an inert solvent is added during the polymerization of butadiene so that the vapors generated after degassing (which contain unreacted monomer and solvent) have to be separated and dried costly in order to make them reused for the anion in the polymerization reaction.

The object of the present invention was to develop a process for the production of ABS molding compositions by polymerisation in rubber-containing solutions which does not exhibit the above-mentioned disadvantages when suitable catalysts are used. The method should in particular make it possible to use the rubber solution directly in the production of ABS molding compositions, ie without isolating and redissolving the rubber in the vinylaromatic compound.

This object is achieved by a rubber-containing solution produced by polymerizing a diene in a solution of vinylaromatic monomer.

The present invention further relates to containing

A) at least one rare earth metal compound,

B) at least one organoaluminum compound and

C) Optional Lewis Acid, catalyst for polymerization.

It has surprisingly been found that the process according to the invention can be carried out without the addition of inert solvents.

The rubber solutions used are obtained in a continuous or batch process. In this way polymers are formed in which the content of double bonds in the cis position (relative to the butadiene content) is greater than 90%, preferably greater than 95%, and the content of 1,2 units with pendant vinyl groups is extremely low (ie <2%) where the glass transition temperature of the polymer is below -100°C.

The rubber solution to be used is at a temperature of -30-110°C, preferably at a temperature of -20-100°C, particularly preferably at a temperature of 20-90°C, in the presence of a catalyst based on a rare earth metal compound and as It is obtained by polymerizing dienes in the presence of vinyl aromatic monomers in solvents.

Conjugated dienes preferably used are, for example, 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, 2,4-hexadiene, 1,3-pentadiene and and/or 2-methyl-1,3-pentadiene, particularly preferably 1,3-butadiene.

The molar ratios employed for catalyst components A and C can vary within wide limits.

The molar ratio of component A to component B can be from 1:1 to 1:1000, preferably from 1:3 to 1:200, particularly preferably from 1:3 to 1:100. The molar ratio of component A to component C may be 1:0.02-1:15, preferably 1:0.4-1:5. When aluminoxanes (III) and (IV) are used as component B, component C may be completely or partially omitted.

Particularly contemplated rare earth metal compounds (component (A)) are those selected from the group consisting of:

- rare earth metal alkoxides,

- rare earth metal phosphonates, phosphinates and/or phosphates,

- rare earth metal carboxylates,

- complexes of rare earth metals with diketones and/or

- addition compounds of rare earth metal halides with oxygen or nitrogen donor compounds.

The above-mentioned rare earth metal compounds are described in more detail, for example, in EP 11184.

The rare earth metal compound is based in particular on elements with atomic numbers 21, 39 and 57-71. Preferably used rare earth metals are lanthanum, praseodymium or neodymium or mixtures of rare earth metals containing at least 10 wt.% of at least one of the elements lanthanum, praseodymium or neodymium. Very particularly preferably used rare earth metals are lanthanum or neodymium, which in turn can be admixed with other rare earth metals. The proportion of lanthanum and/or neodymium in the mixture is particularly preferably at least 30% by weight.

Particularly conceivable rare earth metal alkoxides, phosphonates, phosphinates, phosphates and carboxylates or complexes of rare earth metals with diketones are those in which the organic groups present in the compounds contain, inter alia, Linear or branched alkyl residues of 1-20 carbon atoms, preferably 1-15 carbon atoms, such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, isopropyl, isobutyl , tert-butyl, 2-ethylhexyl, neopentyl, neooctyl, neodecyl or neododecyl.

Rare earth alkoxides which may be mentioned are, for example:

Neodymium (III) n-propoxide, Neodymium (III) n-butoxide, Neodymium (III) n-decyl alkoxide, Neodymium (III) isopropoxide, Neodymium (III) 2-ethylhexanolate, Praseodymium ( III) n-propoxide, praseodymium (III) n-butoxide, praseodymium (III) n-decyl alkoxide, praseodymium (III) isopropoxide, praseodymium (III) 2-ethylhexanolate, lanthanum (III) n-propoxide, lanthanum(III) n-butoxide, lanthanum(III) n-decoxide, lanthanum(III) isopropoxide, lanthanum(III) 2-ethylhexoxide, preferably neodymium(III) n-propoxide Butylate, Neodymium(III) Decylate, Neodymium(III) 2-Ethylhexanolate.

Rare earth phosphonates, phosphinates and phosphates which may be mentioned are, for example:

Neodymium(III) Dibutylphosphonate, Neodymium(III) Dipentylphosphonate, Neodymium(III) Dihexylphosphonate, Neodymium(III) Diheptylphosphonate, Neodymium(III) Dioctylphosphonate Phosphonates, Neodymium(III) Dinonylphosphonate, Neodymium(III) Didodecylphosphonate, Neodymium(III) Dibutylphosphinate, Neodymium(III) Dipentylphosphinate Salt, Neodymium(III) Dihexylphosphinate, Neodymium(III) Diheptylphosphinate, Neodymium(III) Dioctylphosphinate, Neodymium(III) Dinonylphosphinate, Neodymium(III) (III) Didodecylphosphinates, preferably neodymium(III) dioctylphosphonate and neodymium(III) dioctylphosphinate.

Suitable rare earth metal carboxylates are:

Lanthanum(III) propionate, Lanthanum(III) diethylacetate, Lanthanum(III) 2-ethyl-hexanoate, Lanthanum(III) stearate, Lanthanum(III) benzoate, Lanthanum(III) cyclohexane formate, lanthanum(III) oleate, lanthanum(III) visanate (versatat), lanthanum(III) naphthenate, praseodymium(III) propionate, praseodymium( III) diethyl acetate, praseodymium (III) 2-ethylhexanoate, praseodymium (III) stearate, praseodymium (III) benzoate, praseodymium (III) cyclohexane formate, Praseodymium(III) Oleate, Praseodymium(III) Visanate, Praseodymium(III) Naphthenate, Neodymium(III) Propionate, Neodymium(III) Diethyl Acetate, Neodymium(III)2 - Ethyl-hexanoate, Neodymium(III) stearate, Neodymium(III) benzoate, Neodymium(III) cyclohexane carboxylate, Neodymium(III) oleate, Neodymium(III) vitamin Salts of neodymium (III) naphthenate, preferably neodymium (III) 2-ethylhexanoate, neodymium (III) visanate, neodymium (III) naphthenate. Neodymium visanate is particularly preferred.

Coordination compounds of rare earth metals with diketones that may be mentioned are:

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

Addition compounds of rare earth metal halides with oxygen or nitrogen donor compounds that may be mentioned are, for example:

Lanthanum(III) chloride and tributyl phosphate, lanthanum(III) chloride and tetrahydrofuran, lanthanum(III) chloride and isopropanol, lanthanum(III) chloride and pyridine, lanthanum(III) chloride and 2- Ethylhexanol, Lanthanum(III) Chloride and Ethanol, Praseodymium(III) Chloride and Tributyl Phosphate, Praseodymium(III) Chloride and Tetrahydrofuran, Praseodymium(III) Chloride and Isopropanol, Praseodymium(III) Chloride( III) with pyridine, praseodymium(III) chloride with 2-ethylhexanol, praseodymium(III) chloride with ethanol, neodymium(III) chloride with tributyl phosphate, neodymium(III) chloride with tetrahydrofuran, chlorine Neodymium(III) chloride and isopropanol, Neodymium(III) chloride and pyridine, Neodymium(III) chloride and 2-ethylhexanol, Neodymium(III) chloride and ethanol, Lanthanum(III) bromide and phosphoric acid Tributyl Ester, Lanthanum(III) Bromide and THF, Lanthanum(III) Bromide and Isopropanol, Lanthanum(III) Bromide and Pyridine, Lanthanum(III) Bromide and 2-Ethylhexanol, Lanthanum(III) Bromide (III) with ethanol, praseodymium(III) bromide with tributyl phosphate, praseodymium(III) bromide with tetrahydrofuran, praseodymium(III) bromide with isopropanol, praseodymium(III) bromide with pyridine, praseodymium(III) bromide (III) and 2-ethylhexanol, praseodymium (III) bromide and ethanol, neodymium (III) bromide and tributyl phosphate, neodymium (III) bromide and tetrahydrofuran, neodymium (III) bromide and isopropyl Alcohol, Nd(III) bromide and pyridine, Nd(III) bromide and 2-ethylhexanol, Nd(III) bromide and ethanol, preferably Lanthanum(III) chloride and tributyl phosphate, Lanthanum chloride (III) and pyridine, lanthanum (III) chloride and 2-ethylhexanol, praseodymium (III) chloride and tributyl phosphate, praseodymium (III) chloride and 2-ethylhexanol, neodymium chloride ( III) with tributyl phosphate, neodymium (III) chloride with tetrahydrofuran, neodymium (III) chloride with 2-ethylhexanol, neodymium (III) chloride with pyridine, neodymium (III) chloride with 2-ethylhexanol Hexyl Alcohol, Neodymium(III) Chloride and Ethanol.

Very particularly preferably used rare earth metal compounds are neodymium visanate, neodymium octanoate and/or neodymium naphthenate.

The above-mentioned rare earth metal compounds can be used either alone or in combination.

Compounds used as organoaluminum component B are selected from trialkylaluminums, dialkylaluminum hydrides and/or aluminoxanes of the following general formulas (I)-(IV):

AIR ₃ (I), HAIR ₂ (II),

In the general formulas (I)-(IV) of component B, each R can be the same or different and refers to linear and branched alkyl residues with 1-10 carbon atoms, preferably 1-4 carbon atoms, Cycloalkyl residues having 3-20 carbon atoms and aryl residues having 6-20 carbon atoms and n means 1-50. Examples of suitable aluminum alkyls of the general formulas (I) and (II) are: trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum Aluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, tricyclooctylaluminum, diethylaluminum hydride, di-n-butylaluminum hydride and diisobutylaluminum hydride. Triethylaluminum, triisobutylaluminum and diisobutylaluminum hydride are preferred.

Examples of aluminoxanes (III) and (IV) that may be mentioned are methylalumoxane, ethylalumoxane and isobutylalumoxane, preferably methylalumoxane and isobutylalumoxane.

The aluminum alkyls can be used alone or mixed with each other.

So-called Lewis acids are used as component C. Examples that may be mentioned are organometallic halides in which the metal atom belongs to group 3a or 4a, and halides of elements of 3a, 4a and 5a of the periodic table, as in Handbook of Chemistry & Physics, p. 45 Edition, 1964-65. The following may be mentioned in particular:

Methylaluminum dibromide, methylaluminum dichloride, ethylaluminum dibromide, ethylaluminum dichloride, butylaluminum dibromide, butylaluminum dichloride, dimethylaluminum bromide, chlorine Dimethyl aluminum chloride, diethyl aluminum bromide, diethyl aluminum chloride, dibutyl aluminum bromide, dibutyl aluminum chloride, methyl aluminum sesquibromid, methyl aluminum trichloride , ethylaluminum tribromide, ethylaluminum trichloride, aluminum tribromide, antimony trichloride, antimony pentachloride, silicon tetrachloride, methyltrichlorosilane, dimethyldichlorosilane, trimethyl Ethylchlorosilane, Ethyltrichlorosilane, Diethyldichlorosilane, Triethylchlorosilane, Vinyltrichlorosilane, Divinyldichlorosilane, Trivinylchlorosilane, Phosphorus Trichloride, Pentachloride Phosphorus, tin tetrachloride.

Diethylaluminum chloride, ethylaluminum trichloride, ethylaluminum dichloride, diethylaluminum bromide, ethylaluminum tribromide and/or ethylaluminum dibromide are preferably used.

Reaction products of aluminum compounds (expressed as component B) with halogens or halogen compounds, for example triethylaluminum with bromine or triethylaluminum with butyl chloride, can also be used as component C. In this case, the reaction can be carried out alone, or the amount of the alkylaluminum compound required for the reaction can be added to the amount required as component B.

Ethylaluminum trichloride, butyl chloride and butyl bromide are preferred.

When aluminoxanes (III) and (IV) are used as component B, component C may be completely or partially omitted.

It is also possible to add the other component D to the catalyst components A-C which have proved to be effective in experiments. The component D may be a conjugated diene, which is the same diene subsequently 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 (relative to 1 mol of component A), particularly preferably 1 to 100 mol. Very particularly preferably, 1 to 50 mol of D are used relative to 1 mol of component A.

When producing the rubber solution, the catalyst is used in an amount of 1 μmol to 10 mmol, preferably 10 μmol to 5 mmol of the rare earth metal compound relative to 100 g of the monomer.

It is of course also possible to use these catalysts in any mixtures with one another.

The rubber solution is in the presence of vinyl aromatic monomers, especially styrene, α-methylstyrene, α-methylstyrene dimer, p-methylstyrene, divinylbenzene and/or other Produced in the presence of alkylstyrenes (preferably having 2-6 carbon atoms in the alkyl residue).

The rubber solution is particularly preferably produced in the presence of styrene, α-methylstyrene, α-methylstyrene dimer and/or p-methylstyrene as solvent. Styrene, α-methylstyrene and/or α-methylstyrene dimer and mixtures thereof are very particularly preferred.

The solvents can be used alone or as a mixture.

The amount of vinylaromatic monomer used as solvent is generally from 10 g to 2000 g, preferably from 100 to 1000 g, very particularly preferably from 200 to 500 g, relative to 100 g of the monomers used.

The rubber solution is preferably produced at a temperature of -20 to 100°C, particularly preferably at a temperature of 20 to 90°C. The reaction can be carried out without pressure or under elevated pressure (0.1-12 bar). The production process is carried out continuously or discontinuously, preferably continuously.

It is also possible to remove a portion of the solvent used and/or unreacted monomers after the polymerization, preferably by means of distillation, optionally under reduced pressure, in order to obtain the desired polymer concentration.

The rubber-modified thermoplastic molding compositions according to the invention are preferably produced by free-radical polymerization of vinylaromatic monomers and ethylenically unsaturated nitrile monomers. According to the invention, the reaction is carried out by adding ethylenically unsaturated nitrile monomers and optionally The addition of other vinylaromatic monomers is carried out optionally, and optionally in the presence of a solvent.

Polybutadiene solutions in styrene, α-methylstyrene and/or α-methylstyrene dimer and mixtures thereof produced as described above are preferably used in the rubber-modified thermoplastics of the present invention. The molding composition is neutralized and used in the method according to the invention for producing the composition.

Vinylaromatic monomers which undergo free-radical polymerization with the ethylenically unsaturated nitrile monomers and thus form the homogeneous phase (matrix phase) of the molding composition are those which are used for the production of rubber solutions. Ring-substituted chlorostyrenes can additionally be used together with these monomers as a mixture.

The ethylenically unsaturated nitrile monomers are preferably acrylonitrile and methacrylonitrile, with acrylonitrile being particularly preferred.

Furthermore, acrylic acid monomers or maleic acid derivatives can be used in amounts of up to 30 wt.%, preferably up to 20 wt.% of the total amount of monomers: examples are methyl (meth)acrylate, ethyl (meth)acrylate Esters, tert-butyl (meth)acrylate, esters of fumaric acid, esters of itaconic acid, maleic anhydride, maleic acid esters, N-substituted maleimides, ideally such as N-cyclohexyl - or N-phenylmaleimide, N-alkylphenylmaleimide, and acrylic acid, methacrylic acid, fumaric acid, itaconic acid or their amides.

The ratio of vinylaromatic monomer to ethylenically unsaturated nitrile monomer in the ABS molding composition according to the invention is 60-90 wt. %: 40-10 wt. %, relative to the matrix phase. The rubber content in the ABS molding composition of the invention is 5-35 wt.%, preferably 8-25 wt.%, relative to the ABS molding composition.

In the case of radical polymerization in a solvent, solvents which come into consideration are aromatic hydrocarbons such as toluene, ethylbenzene, xylene and ketones such as acetone, methyl ethyl ketone, pentanone, 2-hexanone and mixtures of these solvents. Ethylbenzene, methyl ethyl ketone and acetone, and mixtures thereof are preferred.

The polymerization is ideally initiated by free-radical initiators, but can also be carried out thermally; the molecular weight of the polymers obtained can be adjusted by molecular weight regulators.

Suitable initiators for free radical polymerization are graft-active peroxides that decompose into free radicals, such as peroxycarbonate (Peroxycarbonate), peroxydicarbonate, diacyl peroxide, peroxyaldehyde (Perketale) or dialkyl peroxides and/or azo compounds or mixtures thereof. Examples are dinitrile azobisisobutyrate, alkyl azoisobutyrates, tert-butyl perpivalate, tert-butyl peroctoate, tert-butyl perbenzoate, tert-perneodecanoate Butyl ester, tert-butyl per(2-ethylhexyl)carbonate. These initiators are used in amounts of 0.005-1 wt.%, relative to the monomers.

This can be achieved by using common molecular weight regulators such as mercaptans, olefins, e.g. tertiary dodecyl mercaptan, n-dodecyl mercaptan, cyclohexene, terpine in an amount of 0.05-2 wt.% relative to the monomers oil, α-methylstyrene dimer to adjust the molecular weight.

The method according to the invention can be carried out in a discontinuous, semi-continuous and continuous manner. In a continuous embodiment, the rubber solution, monomer, and optional solvent can ideally be fed, mixed, and stirred tank-type at steady-state monomer conversion after a phase inversion of greater than 10%. Polymerization is carried out in the first stage in the reactor, then free radical initiated polymerization is continued while mixing in one or more additional continuously operated stirred tanks in series or in mixed plug flow reactors and A monomer conversion of 30-90% is carried out in at least one additional stage in a combination of/or two types of reactors. Residual monomers and solvents can be evaporated using common methods (e.g. in heat exchange evaporators, flash evaporators, line evaporators, thin film evaporators, screw evaporators, stirred heterogeneous evaporation with kneading and extraction devices) device) to remove (where it is also possible to use blowing or entraining agents, such as water vapor), and return to the process. Additives, stabilizers, antioxidants, fillers, lubricants can be added during polymerization and during isolation of the polymer.

Discontinuous and semi-continuous polymerizations are carried out in one or more series of full or partially filled mixing tanks, wherein rubber solution, monomers and optional solvent are initially introduced and polymerized to 30-90% of the total The above-mentioned monomer conversion rate.

Mixing and dispersion of the introduced rubber solution can be improved by pumping the slurry in continuous or discontinuous circulation by means of mixing and shearing devices. Loop reactors are known in the art and can be used to determine the particle size of rubber. However, it is more desirable to have a shear device between the two separate reactors to avoid back mixing which would result in a broadening of the particle size distribution.

The average residence time is 1-10 hours, preferably 2-6 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 a rubber particle size with a diameter (weight average, _dw ) of 0.1-10 μm, preferably 0.1-2 μm.

The molding compositions according to the invention can be thermoplastically processed to moldings by extrusion, injection molding, calendering, blow molding, pressing and sintering methods.

Example

Measurement methods

The solution viscosity of rubber solution is to measure (Brookfield RV, SyncroLectric, LVT type, mandrel 2 by using Brookfield (Brookfield) viscometer at 25 ℃ to 5wt.% solution measurement, can set speed to 6,12 according to viscosity , 30, 60Upm fixed speed).

Conversion was determined by determining the solids content after evaporation at 200°C. The rubber content in the final product is determined from mass balance. The gel content is determined in acetone as dispersion medium. The intrinsic viscosity of the soluble fraction was measured using dimethylformamide + 1 g/L LiCl as solvent. Particle size and particle size distribution were measured following the centrifugation method described in US 5,166,261; instead of said method, a dispersion of rubber particles in propylene carbonate was injected into a mixture of propylene carbonate/acetone (75:25) ; weight average (d _W ), area average (d _A ) and number average (d _N ) are stated. The notched impact strength (a _K -Izod) was measured according to ISO 180/1A at 23° C. and the melt volume index (MVI 220° C./10 kg) according to DIN 53735. The phase was investigated by the kinetic, mechanical measurement of the shear modulus parameter G ^* (T) on NKS in the temperature range -150-200 °C and at a frequency of about 1 Hz using the RDA II from Rheometrics. structure. The glass transition temperatures (Tg) of the soft and matrix phases were determined. The corrected shear modulus (G'korr. (RT)) at 23°C was also determined. The measurements were carried out on injection-molded moldings at a melt temperature of 240° C. and a mold temperature of 70° C.

Production of rubber solutions

Air and water vapor were excluded, and the polymerization was carried out under an argon atmosphere. The polymers were isolated from solutions in styrene as described in some of the examples for the sole purpose of characterizing the polymers obtained. The polymer can of course also be stored in solution in styrene without isolation and processed further accordingly. Styrene used as a solvent for the polymerization of dienes was dried over molecular sieves. The microstructure of polybutadiene (1,4-cis, 1,4-trans and 1,2-content) and polystyrene formed by free-radical polymerization was determined by infrared spectroscopic analysis.

Examples A-D

Polymerization was carried out in a 40L steel reactor equipped with an anchor stirrer (100 Upm). The catalyst components were added to a solution of butadiene in styrene at room temperature in the following order: 1) diisobutylaluminum hydride (DIBAH, as a 3.2 molar solution in hexane), 2) neodymium Visanate (NDV, as a 0.24 molar solution in cyclohexane), 3) ethyl aluminum trichloride (EASC, as a 0.1 molar solution in hexane). After adding the last components, the temperature was raised to 65°C. The reaction temperature was maintained at 65-70°C during the polymerization. In Examples C and D, only a part (40%) of the amount of butadiene was introduced initially and the remainder was introduced within 1 hour of the polymerization once after the temperature was raised to 65°C. After the reaction time was over, the polymer solution was transferred to the second reactor (80L reactor, anchor stirrer, 100Upm) and was added by adding 500g of butanone and 18g of p-2,5-di-tert-butyl Polymerization was terminated with octyl phenol propionate (Irganox 1076, Ciba Geigy) and 18 g of tris-(nonylphenyl) phosphite (Irgatos TNPP, Ciba Geigy). Unreacted butadiene was removed by reducing the pressure in the reactor to 200 mbar within 1 hour and to 100 mbar within 2 hours at 50°C.

The batch sizes, reaction conditions and properties of the polymers obtained are given in the table below. Example A B C D. aggregation condition Styrene [kg] 16.9 16.9 16.9 16.9 Butadiene [kg] 4.25 4.25 4.9 4.9 DIBAH [mmol] 300 320 320 270 EASC [mmol] 5.4 5.4 6.5 6.5 NDV [mmol] 8.0 8.0 9.8 9.8 temperature [°C] 60 70 65 63 time [min] 390 165 150 240 rubber solution BR content[wt.%] 14.3 16.7 20.9 18.9 PS content [wt.%] 0.6 1.5 1.4 0.8 rubber cis content[%] ^a) 96 96 96 96 1,2 content [%) ^a) 1 1 1 1 T _g [°C] -108 -109 -110 -109 Viscosity (5% solution) [mPas] 83 41 39 58

^a) Content of 1,4-cis and 1,2 units relative to polybutadiene.

Production of the ABS molding compositions of Examples 1-6

From rubber solution, styrene, acrylonitrile, butanone (MEK), p-2,5-di-tert-butylphenol octyl propionate (Irganox 1076, Ciba Geigy) and α-methylstyrene dimer ( Solution I composed of AMSD) was mixed with an anchor stirrer (150 Upm) at 40° C. in a 5 L flat ground joint kettle equipped with an anchor stirrer and a reflux condenser. After the solution was heated to 82-85° C., initiator solution II consisting of butanone and tert-butyl perpivalate (t-BPPIV) was added within 4 hours. The temperature of the entire reaction was controlled in such a way that the mixture was gently refluxed (82-85°C). Two hours after the start of the addition of solution II, solution III consisting of butanone and α-methylstyrene dimer was added in 1-2 minutes, then the stirrer was set at 100 Upm. After the addition of solution II was complete, stirring was continued at 85° C. for a further 2 hours, then the temperature was lowered to room temperature. The mixture was prepared by adding octyl p-2,5-di-tert-butylphenol propionate (Irganox 1076, Ciba Geigy) and dilauryl dithiopropionate (Irganox PS 800, Ciba Geigy) in butanone solution to stabilize. The solution was then devolatilized and pelletized in a ZSK-laboratory twin-screw devolatilizing extruder (Eindampfschnecke). The pellets were injection molded into standard bars.

The table below shows the formulation compositions, the results of polymerization and the properties of the ABS molding compositions.

Composition of the recipe (all values are in g) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Solution I Example A 932.2 932.2 - - - - Example B - - 820.4 - - - Example C - - - 712.5 - - Example D - - - - 755 755 Irganox 1076 0.3 0.3 0.3 0.3 0.3 0.3 Styrene 415.4 415.4 544.6 645.9 608.2 608.2 Acrylonitrile 408 408 408 408 408 408 MEK 544.4 544.4 527 533.6 528.9 528.9 AMSD 1.6 0.8 2.4 4.8 2.4 4.8 Solution II MEK 150 150 150 150 150 150 t-BPPIV (75%) 6.4 7.42 7.42 7.46 7.46 7.46 Solution III MEK 50 50 50 50 50 50 AMSD 9.6 4.8 7.2 4.8 7.2 4.8 Solution IV MEK 250 250 250 250 250 250 Irganox 1076 2.22 2.22 2.22 2.22 2.22 2.22 Irganox PS 800 3.33 3.33 3.33 3.33 3.33 3.33

result Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Monomer conversion rate [%] 56.1 62.7 58.4 55.6 57.4 56.2 Rubber content in ABS [%] 14.0 12.8 13.5 14.1 13.8 14.0 Gel content[%] 27.0 27.1 26.7 28 30.4 28.8 degree of grafting 0.93 1.117 0.972 0.983 1.211 1.059 intrinsic viscosity 0.551 0.674 0.576 0.514 0.561 0.529 MVR(220℃/10kg)[g/10′] 5.5 2.6 5.2 10.5 4.9 7.6 _dw [μm] 1.094 0.993 0.249 0.566 0.502 0.480 d _a [μm] 0.353 0.252 0.113 0.134 0.205 0.157 d _n [μm] 0.140 0.103 0.072 0.082 0.115 0.090

Properties of ABS molding compositions Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Notched impact strength, 23℃[kJ/m ² ] 23.0 18.6 21.2 24.8 25.6 26.8 Tg-soft phase [℃] -106 -108 -107 -105 -104 -104 Tg-substrate [°C] 110 110 106 108 108 108 G′ _korr .(RT)[MPa] 915 970 915 870 860 835

Claims (23)

1. Process for producing an ABS molding composition, wherein I. First produce a solution containing rubber and II. The polymerization reaction to produce the ABS molding composition is then carried out in the presence of this solution containing rubber, The solution characterized in that it contains rubber is produced by polymerizing dienes in a solution of vinylaromatic monomers in the presence of a catalyst comprising: A) at least one rare earth metal compound, B) at least one organoaluminum compound and C) Optional Lewis acid. 2. The method for producing an ABS molding composition according to claim 1, characterized in that styrene, α-methylstyrene, α-methylstyrene dimer, p-methylstyrene, divinylbenzene, alkanes Styrenes, or mixtures thereof, are used as the vinyl aromatic monomer. 3. Process for producing ABS molding compositions according to claims 1 and 2, characterized in that styrene, α-methylstyrene, α-methylstyrene dimer or mixtures thereof are used as the vinyl aromatic monomer. 4. Process for producing ABS molding compositions according to claims 1-3, characterized in that conjugated dienes are used. 5. The method for producing ABS molding compositions according to claims 1-4, characterized in that 1,3-butadiene, isoprene, 2,3-dimethylbutadiene, 2,4-hexadiene ene, 1,3-pentadiene, 2-methyl-1,3-pentadiene or a mixture thereof is used as the conjugated diene. 6. Process for the production of ABS molding compositions according to claims 1-5, characterized in that alkoxides of rare earth metals, phosphonates, phosphinates, phosphates, carboxylates, coordination of rare earth metals with diketones Compounds or addition compounds of rare earth metal halides with oxygen or nitrogen donor compounds are used as catalyst component A. 7. Process for producing ABS molding compositions according to claims 1-6, characterized in that trialkylaluminums, dialkylaluminum hydrides or aluminoxanes are used as the organoaluminum component B. 8. Process for the production of ABS molding compositions according to claims 1 to 7, characterized in that organometallic halides in which the metal atoms belong to group 3a or 4a of the periodic table are used as component C. 9. Process for producing ABS molding compositions according to claims 1-8, characterized in that as component C halides of elements of groups 3a, 4a or 5a of the periodic table are used. 10. Process for producing ABS molding compositions according to claims 1-9, characterized in that conjugated dienes are added to catalyst components A to C. 11. The method for producing an ABS molding composition according to claims 1-10, characterized in that the molar ratio of component A to component B is 1:1 to 1:1000 and the molar ratio of component A to component C is 1:0.02-1:15. 12. Process for the production of ABS molding compositions according to claims 1-11, characterized in that a catalyst is used which contains A) at least one rare earth metal compound, and B) Aluminoxanes. 13. Process for the production of ABS molding compositions according to any one of claims 1-12, characterized in that the rubber solution is obtained by polymerizing dienes without the addition of inert solvents. 14. Process for producing ABS molding compositions according to one or more of claims 1 to 13, characterized in that it is carried out continuously or discontinuously. 15. Process for producing an ABS molding composition according to claims 1-14, characterized in that the rubber solution is produced at a temperature of -30 to 110°C. 16. Process for producing an ABS molding composition according to claims 1-15, characterized in that the rubber solution is produced without pressurization. 17. Process for producing an ABS molding composition according to claims 1-16, characterized in that the rubber solution is produced at an elevated pressure of 0.1-12 bar. 18. Process for the production of ABS molding compositions according to claims 1-17, characterized in that unsaturated nitrile monomers are used during the polymerization for the production of ABS molding compositions in the presence of rubber-containing solutions. 19. Process for the production of ABS molding compositions according to claims 1-18, characterized in that additionally up to 30% of acrylic acid monomers or maleic acid derivatives are used, relative to the total amount of monomers. 20. ABS molding compositions, characterized in that they are obtainable by using a process according to one or more of claims 1-19. 21. ABS molding composition according to claim 20, characterized in that the content of double bonds in the cis position is greater than 90% and the content of 1,2 units with pendant vinyl groups is less than 2%. 22. Use of the ABS molding compositions according to claims 20 and 21 for the production of moldings. 23. Molded articles obtainable from the ABS molding composition according to claim 20.