DE102004013008A1 - Molding compositions comprising rubber finely dispersed in thermoplastic matrix, obtained by mixing organic solvent solutions of rubber and plastics having specific viscosity ratio - Google Patents

Abstract

In the production of molding compositions (A) comprising a rubber (I) dispersed in a thermoplastic matrix (II), by (a) preparing (I) in an emulsion, (b) isolating (I) by coagulation followed by removal of water in one or more stages, (c) mixing (I) with an organic solvent, (d) blending the mixture (M1) with a mixture (M2) of (II) and an organic solvent, (e) removing the solvent from the obtained mixture (M3) and (f) processing the product, the ratio of the viscosity of (M1) to that of (M2) is 1:100 to 100:1. An independent claim is included for apparatus for carrying out the process, the apparatus not being specifically described in general terms in the independent claim but preferably being such that several mixtures (M3) with different (I)/(II) ratios can be prepared in step (d) and further processed separately in steps (e) and (f).

Description

• A) Herstellen des Kautschuks in Emulsion,
• B) Isolieren des Kautschuks aus der Emulsion durch b1) Koagulation des Kautschuks b2) Entfernen von Wasser in einem ein- oder mehrstufigen Vorgang,
• C) Mischen des unter B) erhaltenen Kautschuks mit einem organischen Lösungsmittel,
• D) Mischen der unter C) erhaltenen Mischung M1) mit einer Mischung der thermoplastischen Matrix mit einem organischen Lösungsmittel (M2))
• E) Entfernen des Lösungsmittels aus der unter D) erhaltenen Mischung M3) und
• F) Aufarbeiten des unter E) erhaltenen Produktes.

The present invention relates to a process for the preparation of molding compositions containing a thermoplastic matrix (T) and a rubber (K) dispersed therein, comprising the following steps

• A) Preparation of the rubber in emulsion,
• B) isolating the rubber from the emulsion by b1) coagulating the rubber b2) removing water in a single or multistage process,
• C) mixing the rubber obtained under B) with an organic solvent,
• D) mixing the mixture M1) obtained under C) with a mixture of the thermoplastic matrix with an organic solvent (M2))
• E) removing the solvent from the mixture M3) obtained under D) and
• F) working up of the product obtained under E).

Of Furthermore, the present invention relates to a device for To run the method according to the invention. Further embodiments The present invention are the claims, the description and to take the examples. It is understood that the above mentioned and to be explained below features of the method according to the invention not only in the specified combination, but also in Other combinations are usable without the scope of the invention to leave.

One Problem in the production of graft modified rubber Thermoplastics is the graft rubbers especially fine to disperse in the thermoplastic matrix. Another known The problem is to produce such blends as low as possible energy.

According to the state Technically, these problems can be solved, for example, by the fact that the Graft rubber during the manufacturing process to the final product always as a dispersion or only slightly agglomerated.

So is proposed in EP-A 203 511 a method in which water is removed from a biphasic mixture. The biphasic mixture In addition to water, the graft rubber in latex form comprises an agent for coagulating the same, at least one thermoplastic and a organic solvent, in which the thermoplastic is soluble. According to the disclosure the order of preparation of the biphasic mixture is arbitrary. Thus, the graft latex can be mixed with the coagulant and then this mixture with the organic solvent and the thermoplastics are mixed. The graft latex but also first with the organic solvent mixed and precipitated by adding an aqueous solution of the coagulant and be dehydrated and then added to the thermoplastic. According to this Document of the prior art, the thermoplastic is preferred used in powder form.

In EP-A 208 112 discloses a method of the same principle, in which, however, is dispensed with the addition of coagulant. Also, from EP-A 227 098, such a method is apparent in in particular a larger amount on organic solvent is used.

The US 3,700,622 discloses a process for producing ABS. Accordingly, styrene-acrylonitrile copolymers (SAN) can be prepared from styrene and acrylonitrile in the presence of a solvent. After completion of the polymerization reaction, so this document, the resulting SAN reaction mixture can be further used as such or diluted with solvent. The resulting SAN solution is treated with a rubber dispersion. The SAN rubber mixture is subjected to shear forces, generally with coagulant added. Subsequently, the mixture is degassed in a degassing extruder and processed to the final product.

A process for the preparation of molding compositions from SAN and two different graft rubbers is the US 3,931,256 refer to. In this process, a mixture of SAN and a liquid phase of styrene and acrylonitrile can be used. One of the two rubbers is prepared by bulk polymerization and recovered as beads. The beads are dissolved in styrene and acrylonitrile. This solution will continue to be used in the process. The second rubber is prepared by emulsion polymerization and can be mixed according to a process variant with styrene, acrylonitrile and solvent extracts. From this mixture, the water is separated. The three solutions or dispersions are mixed and then degassed in two stages.

According to DE-A 2 400 659 can rubber-modified resins are prepared by adding a first preparation, the SAN block copolymers and the monomers the SAN block copolymer preparation, mixed with a second preparation and subsequently be degassed by flash evaporation. The second preparation can be obtained by using an emulsion prepared in emulsion Dried graft copolymer and then, for example, in a Mixture of styrene and acrylonitrile is dispersed.

The object of the present invention was to find a further improved process for the production of rubber-modified thermoplastics, by means of which the rubbers can be very finely dispersed in the thermoplastic matrix and which, moreover, should be energy-saving and cost-effective. Furthermore, the aim was to obtain molding compositions which have a very light intrinsic color. A particular aim of the invention was to find a method which makes it possible to produce several products with different rubber content in parallel in a system with the least possible expenditure on equipment.

These Task is fulfilled by the method defined above, wherein The relationship the viscosity the mixture M1) to the viscosity the mixture M2) is from 1: 100 to 100: 1.

Thermoplastic matrix (T)

In the method according to the invention can in principle, all plastics that process thermoplastically and are themselves rubber-free, used as matrix (T) become. This also includes a mixture of two according to the invention or more different thermoplastic materials. The thermoplastic matrix may be e.g. to polyethylenes, Polypropylene, polyester, polyamides, polystyrenes, polycarbonates or Polyarylenesulfide act, including copolymers such as statistical Copolymers or block copolymers are understood.

When Polyamides are partially crystalline, preferably linear, polyamides such as Polyamide-6, polyamide-6,6, polyamide-4,6, polyamide-6,12 and partially crystalline Copolyamides based on these components suitable. Furthermore can semi-crystalline polyamides are used, the acid component wholly or partly of adipic acid and / or terephthalic acid and / or isophthalic and / or suberic acid and / or sebacic and / or azelaic acid and / or dodecane and / or a cyclohexanedicarboxylic acid, and their diamine component in whole or in part, in particular from m- and / or p-xylylenediamine and / or hexamethylenediamine and / or 2,2,4- and / or 2,4,4-trimethylhexamethylenediamine and / or isophoronediamine, and their compositions in the Principle known in the art.

To include the preferred polyesters Polyalkylacrylates, including in particular polymethylmethacrylate or Copolymers thereof, including those containing up to 40% by weight of comonomers, but also aromatic-aliphatic polyester. Examples are polyalkylene terephthalates, e.g. based on ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,4-bis-hydroxymethylcyclohexane, as well as polyalkylene naphthalates.

Farther can Polyoxyalkylenes, e.g. Polyoxymethylene be used.

Prefers are polycarbonates based on diphenyl carbonate and bisphenols. Preferred bisphenol is 2,2-di (4-hydroxyphenyl) propane, generally - as well in the following - as Bisphenol A called. In place of bisphenol A can also other aromatic dihydroxy compounds are used, in particular 2,2-di (4-hydroxyphenyl) pentane, 2,6-dihydroxynaphthalene, 4,4'-dihydroxydiphenylsulfane, 4,4'-dihydroxydiphenyl ether, 4,4'-Dihydroxydiphenylsulfit, 4,4'-Dihydroxydiphenyfmethan, 1,1-di- (4-hydroxyphenyl) ethane, 4,4-dihydroxydiphenyl or dihydroxydiphenyl cycloalkanes, preferably dihydroxydiphenylcyclohexanes or dihydroxylcyclopentanes, in particular 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane and mixtures the aforementioned dihydroxy compounds. Particularly preferred polycarbonates are those based on bisphenol A or bisphenol A together with Up to 80 mol% of the above-mentioned aromatic dihydroxy compounds. It can also copolycarbonates are used; of special interest are copolycarbonates based on bisphenol A and di- (3,5-dimethyl-dihydroxyphenyl) sulfone, characterized by a high heat resistance distinguished.

To The preferred plastics that can be used as a matrix include polystyrenes and their copolymers.

For example it may be SAN (styrene-acrylonitrile), AMSAN (α-methylstyrene-acrylonitrile), styrene-maleimide-maleic anhydride (SNPMIMA), (styrene-maleic acid (anhydride) acrylonitrile polymers or SMSA (styrene-maleic anhydride).

• t1) 60 bis 100 Gew.-%, vorzugsweise von 65 bis 80 Gew.-%, Einheiten eines vinylaromatischen Monomeren, vorzugsweise des Styrols, eines substituierten Styrols oder eines (Meth)acrylsäureesters oder deren Gemische, insbesondere des Styrols oder α-Methylstyrols oder deren Mischungen,
• t2) 0 bis 40 Gew.-%, vorzugsweise von 20 bis 35 Gew.-%, Einheiten eines ethylenisch ungesättigten Monomers, vorzugsweise des Acrylnitrils oder Methacrylnitrils oder Methylmethacrylats, insbesondere des Acrylnitrils.

Preferably, the component is a copolymer, based on T,

• t1) 60 to 100 wt .-%, preferably from 65 to 80 wt .-%, units of a vinyl aromatic monomer, preferably of styrene, a substituted styrene or a (meth) acrylic acid ester or mixtures thereof, in particular of styrene or α-methylstyrene or their mixtures,
• t2) 0 to 40 wt .-%, preferably from 20 to 35 wt .-%, units of an ethylenically unsaturated monomer, preferably of the acrylonitrile or methacrylonitrile or methyl methacrylate, in particular of the acrylonitrile.

In accordance with one embodiment of the invention, the matrix polymer is given from 60 to 99% by weight of vinylaromatic monomers and 1 to 40% by weight of at least one of the others NEN monomers.

According to one embodiment The invention is a matrix polymer, a copolymer of styrene and / or α-methylstyrene used with acrylonitrile. The acrylonitrile content in these copolymers is thereby 0 to 40 wt .-%, preferably 18 to 35 wt .-%, based on the Total weight of T.

The Molecular weights (weight average Mw) are usually in Range of 50,000 to 500,000 g / mol, preferably in the range of 70 000 to 450 000 g / mol.

The Matrix polymers are known per se or can according to the expert known, methods are produced. The proportion of thermoplastic Matrix used in the molding compositions obtained by the method according to the invention can be produced, can vary widely. In general amounts He just so much that the thermoplastic matrix is the continuous phase can form. Often the proportion of the thermoplastic matrix is in the Range of 40 to 95 wt .-%, preferably in the range of 50 to 90 Wt .-%, based on the total weight of the molding compound.

Rubber and its production

through The process of the invention can molding compounds are prepared based on a rubber (K). among them are also understood to be those that are a mixture of two or more different rubbers included. The in the method according to the invention usable rubbers can be different nature. Thus, e.g. graft or rubbers are used with a block structure. The rubbers (K) generally have a glass transition temperature (determined according to DIN 53765) of 0 ° C or underneath. Particularly preferred are rubbers, which with the thermoplastic matrix compatible are. Among the preferred rubbers are graft copolymers.

The Graft copolymers each contain one, formed by a rubber, Phase (soft phase) as a graft base and a graft (hard phase). This should also be understood according to the invention be that several soft and hard phases can be included. The Graft copolymers can also based on rubbers of various monomeric composition or have a different graft pad. Furthermore is it is possible that they have both a different grafting base and a have different Pfropfauflage.

in principle are suitable as a graft base all rubbers having a glass transition temperature of 0 ° C (determined according to DIN 53765) or below. The rubbers can vary greatly Be nature. For example, you can Silicone, olefin, such as ethylene, propylene, ethylene / propylene, EP (D) M, Block rubbers such as styrene / ethylene / butadiene / styrene (SEBS) rubbers, Diene, acrylate, ethylene vinyl acetate, or ethylene butyl acrylate rubbers.

Prefers are used as a grafting base acrylate and diene rubbers.

When Acrylate rubbers are mainly polymers of alkyl acrylates which may be up to 40% by weight, based on the total weight of the Acrylic rubbers, other copolymerizable monomers can. Preferred are C1 to C8 alkyl esters, e.g. Methyl, -, ethyl, butyl, n-octyl and 2-ethylhexyl esters or mixtures of said esters. Particular preference is given to crosslinking acrylate rubbers as the graft base used. The skilled worker is familiar with processes for their preparation. Your Particle diameters (weight average d50) are generally in the range of 0.05 to 10 μm, preferably from 0.1 to 5, in particular from 0.15 to 3 μm (determined according to W. Scholtan and H. Lange, colloid-Z. and Z.-Polymers 250 (1972) pages 782-796, by means of Ultracentrifuge).

• k11) 50 bis 100 Gew.-% mindestens eines Diens mit konjugierten Doppelbindungen und
• k12) 0 bis 50 Gew.-% von einem oder mehreren weiteren monoethylenisch ungesättigten Monomeren,

aufgebaut sind, wobei sich die Gewichtsprozente von k11) und k12) zu 100 addieren.However, diene rubbers are particularly preferably used as the graft base. Very particularly preferred as the graft base are diene rubbers which are made from

• k11) 50 to 100 wt .-% of at least one diene having conjugated double bonds and
• k12) 0 to 50% by weight of one or more further monoethylenically unsaturated monomers,

are constructed, wherein the weight percent of k11) and k12) add up to 100.

When Dienes with conjugated double bonds, k11), come in particular Butadiene, isoprene and their halogen-substituted derivatives, such as Chloroprene, into consideration. Preference is given to butadiene or isoprene, in particular Butadiene.

The other monoethylenically unsaturated monomers k12) which may be present in the diene rubber at the expense of the monomers k11) are, for example:
vinylaromatic monomers, preferably styrene or styrene derivatives such as C1 to C8 alkyl substituted styrenes such as α-methylstyrene, p-methylstyrene, vinyltoluene;
unsaturated nitriles such as acrylonitrile, methacrylonitrile;
aliphatic esters such as C1 to C4 alkyl esters of methacrylic acid or of acrylic acid such as methyl methacrylate, furthermore also the glycidyl esters, glycidyl acrylate and methacrylate;
N-substituted maleimides such as N-methyl, N-phenyl and N-cyclohexylmaleimide;
Acids such as acrylic acid, methacrylic acid; furthermore dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and also their anhydrides such as maleic anhydride;
Nitrogen-functional monomers such as dimethylaminoethyl acrylate, diethylaminoethyl acrylate, vinylimidazole, vinylpyrrolidone, vinylcaprolactam, vinylcarbazole, vinylaniline, acrylamide and methacrylamide;
aromatic and araliphatic esters of (meth) acrylic acid and such as phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, 2-phenylethyl acrylate, 2-phenylethyl methacrylate, 2-phenoxyethyl acrylate and 2-phenoxyethyl methacrylate;
unsaturated ethers such as vinyl methyl ether or vinyl butyl ether.

Of course, come also mixtures of two or more of these monomers into consideration.

preferred Monomers k12) are styrene, acrylonitrile, methyl methacrylate, glycidyl acrylate, methacrylate or butyl acrylate.

The Production of the rubbers (K) takes place according to the invention in emulsion (Step A). According to the invention below be understood that the preparation in the presence of a liquid dispersant (Lyosol) takes place and a liquid or solid dispenser portion is present. Process for the preparation of rubbers in emulsion are known in the art or the preparation can be done by methods known to those skilled in the art.

So can for example, the diene rubbers used as a grafting base be made in a first step, where they do not particulate incurred, for example via solution polymerization or gas phase polymerization and then in a second step in the aqueous phase be dispersed (secondary emulsification).

For the production however, the rubbers are preferred for primary emulsification. So For example, the preparation may be e.g. in a conventional manner by the method Emulsion, Inverse Emulsion, Miniemulsion, Microemulsion, or microsuspension in the feed process, continuously or in batch mode become. The rubbers can also prepared in the presence of a submitted finely divided latex (so-called "seed latex procedure" of the polymerization). Suitable seed latices consist for example of polybutadiene or Polystyrene. in principle Is it possible To mix the rubber directly after its preparation with the matrix or directly as a grafting base to use. You can, however also before a grafting first agglomerated by agglomeration into larger particles become.

method for agglomeration are known in the art or agglomeration can be made by the skilled person known per se methods. So can physical processes such as freeze or pressure agglomeration processes be used. It can But also chemical methods are used to get the primary particles to agglomerate. The latter include the addition of inorganic or organic acids. Preferably, the agglomeration by means of a Ag is glomerisationspolymerisates in the absence or presence of an electrolyte, such as an inorganic one Hydroxide, made. As Agglomerisationspoylmerisate are, for example To name polyethylene oxide polymers or polyvinyl alcohols. To the suitable agglomeration polymers include copolymers of C1- to C 12 -alkyl acrylates or C1 to C12 methalkyl acrylates and polar comonomers such as Acrylamide, methacrylamide, ethacrylamide, n-butylacrylamide or maleic acid amide.

Prefers the rubbers have particle sizes (weight average d50) in the range of 100 to 2500 nm. The particle size distribution is preferably almost or completely monomodal or bimodal.

• k21) 50 bis 100, bevorzugt 60 bis 100 und besonders bevorzugt 65 bis 100 Gew.-% eines vinylaromatischen Monomeren,
• k22) 0 bis 50, bevorzugt 0 bis 40 und besonders bevorzugt 0 bis 35 Gew.-% Acrylnitril oder Methacrylnitril oder deren Mischungen,
• k23) 0 bis 40, bevorzugt 0 bis 30 und besonders bevorzugt 0 bis 20 Gew.-% von einem oder mehreren weiteren monoethylenisch ungesättigten Monomeren,

wobei sich die Anteile der Komponenten k21) bis k23) zu 100 Gew.-% ergänzen.The graft copolymers contain a grafting pad based on an unsaturated monomer, which also means that the grafting pad can be prepared from two or more unsaturated monomers. In principle, the rubbers can be grafted with a wide variety of unsaturated compounds. Corresponding compounds and methods are known per se to the person skilled in the art. Preference is given to containing a graft

• k21) from 50 to 100, preferably from 60 to 100, and particularly preferably from 65 to 100,% by weight of a vinylaromatic monomer,
• k22) 0 to 50, preferably 0 to 40 and more preferably 0 to 35 wt .-% of acrylonitrile or methacrylonitrile or mixtures thereof,
• k23) 0 to 40, preferably 0 to 30 and particularly preferably 0 to 20 wt .-% of one or more further monoethylenically unsaturated monomers,

wherein the proportions of components k21) to k23) add up to 100% by weight.

Suitable vinylaromatic monomers are the vinylaromatic compounds mentioned under k12) or mixtures of two or more thereof, in particular styrene or α-methylstyrene. Other monoethylenically unsaturated monomers include the aliphatic, aromatic and araliphatic esters, acid listed under k12) ren, nitrogen-functional monomers and unsaturated ethers or mixtures of these monomers.

In the graft pad can but also monomers containing functional groups, among which in particular epoxy or oxazoline be mentioned.

you The graft may be in one or more process steps produce. It can the monomers k21), k22) and k23) individually or in mixture miteinan the added become. The monomer ratio The mixture may be constant in time or a gradient. Also Combinations of these procedures are possible.

For example you can do it first Styrene alone, and thereafter a mixture of styrene and acrylonitrile, Polymerize on the graft.

preferred Grafting pads are for example made of styrene and / or α-methyl-styrene and one or more of the other mentioned under k22) and k23) Monomers. Preferred are methyl methacrylate, N-phenylmaleimide, maleic anhydride and acrylonitrile, more preferably methyl methacrylate and acrylonitrile.

• k2-1: Styrol
• k2-2: Styrol und Acrylnitril,
• k2-3: α-Methylstyrol und Acrylnitril,
• k2-4: Styrol und Methylmethacrylat
• k2-5: Alkylacrylat und Methylmethacrylat

Preferred grafting conditions are based on:

• k2-1: styrene
• k2-2: styrene and acrylonitrile,
• k2-3: α-methylstyrene and acrylonitrile,
• k2-4: styrene and methylmethacrylate
• k2-5: alkyl acrylate and methyl methacrylate

Especially is preferred the proportion of styrene or α-methylstyrene, or the proportion of the sum of styrene and α-methylstyrene, at least 40% by weight, based on the graft.

Farther are as already mentioned also Graft copolymers with several "soft" and "hard" stages, especially in case of larger particles.

• k1) 30 bis 95, bevorzugt 40 bis 90, insbesondere 40 bis 85 Gew.-% einer Pfropfgrundlage (d.h. Kautschuk) und
• k2) 5 bis 70, bevorzugt 10 bis 60, insbesondere 15 bis 60 Gew.-% einer Pfropfauflage

enthalten.Preference is given to graft copolymers which (based on the graft copolymer)

• k1) 30 to 95, preferably 40 to 90, in particular 40 to 85 wt .-% of a graft base (ie rubber) and
• k2) 5 to 70, preferably 10 to 60, in particular 15 to 60 wt .-% of a graft

contain.

• k1) 30 bis 95 Gew.-% einer Pfropfgrundlage, enthaltend (bezogen auf b1)) 90 bis 100 Gew.-% Butadien und 0 bis 10 Gew.-% Styrol und
• k2) 5 bis 70 Gew.-% einer Pfropfauflage, enthaltend (bezogen auf b2)) von 65 bis 85 Gew.-% Styrol und von 15 bis 35 Gew.-% Acrylnitril

enthalten.Examples of preferred graft copolymers are those which (based on the graft copolymer)

• k1) from 30 to 95% by weight of a grafting base comprising (based on b1)) from 90 to 100% by weight of butadiene and from 0 to 10% by weight of styrene and
• k2) from 5 to 70% by weight of a grafting pad containing (based on b2)) from 65 to 85% by weight of styrene and from 15 to 35% by weight of acrylonitrile

contain.

• k1) 30 bis 95 Gew.-% einer Pfropfgrundlage, enthaltend n-Butylacrylat und einen Vernetzter und
• k2) 5 bis 70 Gew.-% einer Pfropfauflage, enthaltend (bezogen auf Pfropfauflage) von 65 bis 85 Gew.-% Styrol und von 15 bis 35 Gew.-% Acrylnitril

enthalten.The preferred graft copolymers include, for example, those which (based on K)

• k1) from 30 to 95% by weight of a grafting base containing n-butyl acrylate and a crosslinker and
• k2) 5 to 70 wt .-% of a graft, containing (based on grafting) of 65 to 85 wt .-% of styrene and 15 to 35 wt .-% of acrylonitrile

contain.

According to the invention Grafting done in emulsion. Suitable procedural measures are known in the art. As far as not grafted in the grafting Polymers formed from the monomers k2), these amounts, the usually less than 10% by weight, based on the graft copolymer, assigned to the mass of the matrix (T).

in the General amounts the solids content of the emulsion of 10 obtained in step A) to 70 wt .-%, preferably from 15 to 50 wt .-%.

Isolate the rubber from the emulsion

According to the invention Rubber isolated from the emulsion in two steps. In one first step (b1), the rubber is coagulated. There are many different ones Methods suitable. In general, a precipitant is used. Next the precipitant In coagulation, steam can also be used. It can but they are also purely mechanical methods.

When precipitant are preferably aqueous solutions of water-soluble inorganic or organic acids and / or salts, such as hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, formic acid, acetic acid, propionic acid, citric acid, alkali metal or alkaline earth chlorides, sulfates, formates, acetates, phosphates, carbonates, aluminates, partially hydrolyzed polyvinyl acetates or else Mixtures of the acids mentioned and salts used. Among the preferred precipitating agents include alkaline earth salts, including Magnesium sulfate and calcium formate.

The amount of precipitant needed for the precipitation can vary widely and depends, inter alia, on the type of rubber, its concentration in the aqueous phase and used excipients such as emulsifiers. In general, the amount of precipitant, based on rubber (solid) from 0.1 to 20, preferably from 0.5. to 10% by weight.

The precipitation is generally carried out at normal pressure. She can, too at a pressure lower or higher. That's how the pressure works e.g. in the range of 1 to 10 bar, preferably from 1 to 5 bar. Especially when the precipitation should be made at temperatures above the boiling point of the aqueous Phase in which the rubber is present, the pressure can be higher than Normal pressure lie. The temperature at which the precipitation is carried out can vary within wide limits. For most rubbers have Temperatures in the range of 20 to 140 ° C proved to be favorable. At normal pressure the temperature is generally preferably in the range of 25 to 100 ° C. at Use of steam, its dosage is advantageously made so that the temperature at the precipitation remains within the preferred temperature range. But it can also, the temperature during the precipitation to 10 ° C or below e.g. to below zero ° C to reduce and, for example, down to -5 ° C, in particular to reduce to -3 ° C.

During the precipitation can the watery Phase, for example, sheared. The shear rates are strong from the present system. The shear rate can also be in the course of precipitation be varied. The precipitation can be made in a variety of reactors. To the include suitable reactors stirred tank, Stirred tank cascades, tubular reactors with static mixers, or tubular reactors with dynamic mixers. It is also possible the precipitation in an extruder. The leadership of the precipitation step can be batchwise or continuous or semi-batched.

When Coagulation extruder can be a single-screw or a twin-screw extruder be used. The latter contains preferably two co-rotating screws. The coagulation extruder preferably contains Kneading and / or shearing elements. These can, as is preferred, more than half of processing length turn off. Usually, the coagulation is at a temperature in the range of 150 to 300 ° C carried out. The speed can be very high and e.g. up to 800 rpm. Preferably, the speeds are in the range of 200 to 500 U / min.

To one of the preferred embodiments Is it possible, the rubber by means of shear precipitation to isolate for what As a shear unit, a rotor-stator combination is used. For example, can the emulsion containing the rubber by a shearing machine with at least one shear element having a circular slotted stator and having a slotted rotor rotating within the stator, promoted and the effect of a for a shear coagulation of the dispersion of sufficiently strong shear be subjected. The shear rates are generally higher, if no precipitant is used and lower when in the presence of precipitant is coagulated. The shear rates are in the Rule from 5 to 30 and preferably 6 to 25 m per second. The shear unit contains in general, 1 to 3 successive shear elements, preferably one to two shear elements, with their rotors and stators at least a row of teeth formed by axial slots, but also several have concentrically arranged rows or wreaths of slots or teeth can. In addition to simply slotted rotors rotors are often advantageous, the extra Have knives in the axial and / or radial direction, as well as rotors, the additionally to the shear elements with turbine blade-like Verdrängerleisten are provided, resulting in better product promotion and better suction leads to the dispersion. As a rule, the temperature at which the shear precipitation is carried out adjusted so that it is below the respective temperature, at the the precipitated rubber sinters, i. to larger, coarser particles assembles. In particular, the temperature is in the range of 75 to 95 ° C, preferably in the range of 75 to 90 ° C. This may require it be to cool the shearing unit itself.

In a further step (b2)), the, the precipitated rubber adhering, Water afterwards according to the invention in one one or more stages, for example, two or three stages removed. By this is meant that the water is whole or how it is preferred to be partially removed. For example, the Proportion of water in the rubber after step b2) still up to 20% by weight, preferably up to 15% by weight, based on the mixture of rubber (solid) and water amount. In particular, the residual water content is in the range from 0.1 to 10, in particular 0.1 to 6 wt .-%, based on the mixture Rubber (solid) and water. Step b2) may be e.g. Filtering, sedimenting, Squeezing, decanting, centrifuging, extruding, thermal Drying or microwave drying done. Unless the step b2) is multi-level, it is also possible the water by combination to remove two or more different measures. Of the potential Combinations it is preferred that the rubber an extrusion step and microwave drying.

In one of the preferred embodiments, b2) is single-stage. Particularly preferred is b2) carried out in an extruder. In principle, all screw machines come into consideration, which make it possible to remove the water. Sol che are preferably used in which the water at least partially, preferably for the most part, can be removed in liquid form. Extruders with corresponding drainage zones are known per se to the person skilled in the art.

Especially Preference is given to using twin-screw extruders. Their snails can run concurrently or countering. Preferably, they are concurrent. The snails are designed so that locally tightly limited a pressure gradient occurs and the solids content is jammed. As a result, a phase separation occurs. The material will for example, against a baffle element acting as an obstacle promoted. One can change the pressure depending on the rheological behavior of the rubber and the water content by different arrangement of screw, Build kneading elements or other storage elements. Basically all commercial, suitable for the pressure build-up device elements.

• – überschobene, fördernde Schneckenelemente
• – Schneckenelemente mit Steigung entgegen der Förderrichtung
• – Knetblöcke mit nichtfördernden Knetscheiben in unterschiedlicher Breite
• – Knetblöcke mit rückfördernder Steigung
• – Knetblöcke mit fördernder Steigung
• – Zylinderscheiben, Exzenterscheiben und daraus konfigurierte Blöcke
• – neutrale Stauscheiben ("Drosselscheiben")
• – mechanisch verstellbare Drosseln (Schiebegehäuse, Radialdrosseln, Zentraldrosseln)

genannt.For example, as possible stowage elements

• - pushed, conveying screw elements
• - Screw elements with slope against the conveying direction
• - Knetblöcke with non-promotional kneading discs in different widths
• - Knetblöcke with recirculating slope
• - Knetblöcke with promotional slope
• - Cylinder discs, eccentric discs and blocks configured therefrom
• - neutral baffle plates ("throttle plates")
• - mechanically adjustable throttles (sliding housing, radial throttles, central throttles)

called.

It can also two or more of the baffle elements are combined. Likewise, the congestion effect can be due to the length and intensity of each Damping elements are adapted to the respective rubber. Prefers contains the extruder for pressure buildup screw elements with a slope against the conveying direction.

Prefers are all constructive features and all operating parameters of the extruder advantageously coordinated so that at the selected screw speed of the Although rubber promoted and compressed, but not sintered or fused. It is therefore particularly preferred to remove the water while cooling.

Making the mixture M1)

According to the invention in step B) obtained rubber, which can still adhere residual water, in a further step C) with an organic solvent mixed, whereby the mixture M1) is formed.

• k1) 30 bis 95 Gew.-% einer Pfropfgrundlage, enthaltend (bezogen auf b1)) 90 bis 100 Gew.-% Butadien und 0 bis 10 Gew.-% Styrol und
• k2) 5 bis 70 Gew.-% einer Pfropfauflage, enthaltend (bezogen auf b2)) von 65 bis 85 Gew.-% Styrol und von 15 bis 35 Gew.-% Acrylnitril

enthalten, sowie Ethylbenzol, Styrol und Acrylnitril.Suitable solvents are a wide variety of organic liquids into consideration. The choice of solvent depends on the type of rubber used. In general, organic solvents are used which can keep the rubber in suspension or in which it is partially or completely soluble. As a rule, preference is given to solvents which, owing to their vapor pressure, can also easily be removed thermally again. As solvents, particular preference is given to those which are able to keep in suspension not only the rubber but also the thermoplastic matrix M or in which the matrix (T) is partly or completely soluble. Examples of organic solvents are acetone, ethers such as tetrahydrofuran, alkyl acetates, butyl acetate, ketones such as methyl ethyl ketone, ethylbenzene, toluene or xylene. Of course, solvent mixtures can also be used. Particularly preferred solvents include those in which the matrix is producible. Particularly preferred solvents include ethylbenzene or solvent mixtures containing ethylbenzene. The latter include, in particular, solvent mixtures which, in addition to ethylbenzene, contain monomers which originate from the production process of the matrix (T). Particularly preferred monomers are styrene or styrene derivatives and acrylonitrile. In one of the preferred embodiments, M1) comprises graft copolymers

• k1) from 30 to 95% by weight of a grafting base comprising (based on b1)) from 90 to 100% by weight of butadiene and from 0 to 10% by weight of styrene and
• k2) from 5 to 70% by weight of a grafting pad containing (based on b2)) from 65 to 85% by weight of styrene and from 15 to 35% by weight of acrylonitrile

and ethylbenzene, styrene and acrylonitrile.

Of the Solid content of the mixture M1) can vary within wide ranges and for example from 30 to 70 wt .-%, preferably from 40 to 65 Wt .-%, based on M1).

The preparation of the mixture M1) can in principle be carried out in various ways. Thus, the mixture in a mixing device or in two or more, for example, three mixing devices connected in series become. It is possible to combine each mixing devices of the same type or even those of different types together. Suitable mixing devices may be, for example, pumps such as centrifugal pumps. Suitable mixing devices are above all mixing devices based on the rotor-stator principle, such as dispersing machines or Konius mills. The operating parameters of the mixing device, such as slot dimensions in the rotor and stator of the dispersing machine or gap widths in the Konius mill, introduced energies and rotational speeds depend inter alia on the nature of the rubber and the solvent or the viscosity of the mixture and the desired dispersion coefficient. In general, it is preferred that the rubber have substantially the particle size and particle size distribution that it had prior to its precipitation.

Step D)

According to the invention is in a further step the mixture M1) with a mixture M2) to a M3 mixture).

The Mixture M2) is a mixture according to the invention the matrix (T) in an organic solvent. As organic solvent the above are considered. It is possible to do this separately prepared matrix with an organic solvent to mix. Preferably, however, the mixture M2) from the manufacturing process of Matrix obtained reaction mixture. Preferably, the mixture comprises M2) therefore also monomers which originate from the production of the matrix. Preferably contains the mixture M2) the matrix, ethylbenzene, styrene or styrene derivatives and acrylonitrile. According to one of the preferred embodiments, M2) comprises styrene-acrylonitrile copolymer, Ethylbenzene, styrene and acrylonitrile. In general, the solids content is the mixture M2) in the range of 30 to 70 wt .-%, preferably from 50 to 70 wt .-%.

According to the invention viscosity the mixture M1) is adjusted to the viscosity of the mixture M2), that the ratio the viscosity of the Mixture M1) to the viscosity of M2) is from 1: 100 to 100: 1. Preferably, the ratio of 1: 80 to 80: 1, especially from 1:50 to 50: 1. Especially is preferred The relationship the viscosity from M1) to that of M2) 1: 20 to 20: 1, in particular from 1 to 10 10: 1. For example, the ratio of the viscosity of M1) to that of M2) from 1: 8 to 8: 1. So it is e.g. possible that The relationship the viscosity from M1) to the viscosity of M2) is from 1: 5 to 5: 1. The viscosities from M1) and M2) doing so by means of this suitable measuring method of course, with care being taken that the measurements of the viscosities from M1) and M2) is carried out under the same conditions. Preferably, the viscosities are through determines an on-line measurement by means of a Return Stream Rheometer, Care should be taken that the rheometers are the same Have design with respect to the inlet and outlet pumps, the pum pendrucke, the nozzle, filling the pressure transducer, the size and arrangement the inlets and outlets. Preference is given to the feed and discharge lines and the rheometer itself isolated, so that temperature fluctuations, if any, then only in subordinate Dimensions occur can. It should also be ensured that the rheometers are comparable Be arranged. For example, the viscosity determination by means of two ViscoSenor rheometers from Dynisco with a L / D relationship from 60/1 by measuring the apparent viscosity and the on-line ASTM D1238 melt flow rate be made.

M1) and M2) be mixed with each other in a variety of mixing devices. there Is it possible more than one mixing device, e.g. two or three mixers for the Mixing of M1) and M2) connected in series. Preferably, however, only one mixing device is used. To the particularly preferred mixing devices include static mixers. there both turbulence mixers and laminarmischer come into consideration. The turbulence mixers are both free turbulence generating mixing systems as well as those with fittings into consideration. For the laminar mixers usually those with more than 4, e.g. 4 to 50 installed used. To suitable static mixers include Multiflux mixers, spiral mixers, Vortex mixer, lattice mixer, Sulzer SMX mixer, Sulzer SMV mixer and Kenics mixer.

The Mixture M3) is usually at temperatures in the range of 120 up to 200 ° C, preferably made in the range of 130-190 ° C. The in step D) obtained mixture M3) is at a temperature of 150 ° C or more preferred single-phase with respect to the liquids contained therein.

In Step D) it is possible by appropriate choice of the volumes of M1) and M2) in parallel two or More, for example, three mixtures M3) produce, which in their proportions M1) to M2) differ from each other. The production of different Mixtures M3) in this case may e.g. be done by the Mixtures M3) in different and parallel mixing devices, like the aforementioned static mixers. Of course it is it also possible though not preferred, different mixtures M3) in time produce one after the other and for this purpose in each case a mixing device to use.

Remove the solvent

Of the Invention according to is in a further step E) of the mixture M3) the solvent removed. this includes is to be understood according to the invention that next to the organic solvent even the remaining water is removed. Furthermore, it is below also to understand that different mixtures M3) in parallel in their own devices, the solvent is removed.

methods with which the solvent can be removed, are known in the art. The solvent can be removed in one or more stages. Mostly the Solvent removal in a two-stage or multi-stage, for example three-stage process. Particularly preferably, the removal of the solvent takes place at least in one stages according to the principle of indirect heat exchange. Examples of suitable Devices are evaporators, for example, tube bundle heat exchangers, Schlangenrohrverdampfer or degasser as strand degasser or a Combination of two or more of these devices. That's it possible two or more of these devices are the same type, but be operated under different conditions, one behind the other to switch. But it is also possible, devices of different To switch kind in a row. According to one of the preferred embodiments In a first stage, a shell and tube heat exchanger in a second Stage used a strand degasser. Devices for removal of solvents can be used are for example from WO 99/54017, EP-B1 1 113 848 or WO 02/740 known. The design of devices such as number, length, shape the tube bundle, Dimension or shape of the collection container and the internals of a Tube heat exchanger or, for example, the dimensioning and orientation of the tubes a snake tube evaporator or shape, type and dimensioning of the distributor or the collecting container as well as internals of a Strangentgasers are among other things due to the viscosity of the mixture M3) and throughput.

In usually the mixture has M3) just before removing the solvent in a first stage, a temperature of 130 to 180 ° C. In the Usually, the mixture M3) is pressurized into the device e.g. a tube bundle heat exchanger introduced and relaxed therein, whereby the solvent evaporates. Preferably the mixture M3) is released into a pressure below that saturation pressure of the solvent and possibly still existing water is. In general Therefore, the removal of the solvent takes place in a first Step preferably at pressures ranging from 10 to 100 mbar, particularly preferably in the range from 20 to 30 bar. In a second or in further stages it may be expedient to continue the pressure lower, for example, the residual solvent for printing in Range of 1 to 10 mbar, preferably in the range of 1 to 5 mbar remove. In addition, it may be necessary to change the temperature of to maintain in a first stage concentrated mixture or also, for example, by up to 200 ° C, preferably by up to 180 ° C to increase. The increase the temperature can e.g. by means of a device for intermediate heating be reached, that between the output of a previous one and the entrance of the next Level is. Depending on the type of solvent It may be necessary to have one or a mixture of different easily volatile liquids to be used as an entrainment agent. According to one of the preferred embodiments the removal of the solvent takes place without the addition of an entraining agent.

in the Generally, after removal of the solvent and optionally the residual water, the substantially freed from volatiles molding material as a melt before. As a rule, the proportion of residual solvent including water not more than 800 ppm, preferably not more than 600 ppm, based on the melt. Depending on the type of matrix and the Rubber may vary the temperature of the melt, e.g. in the Range from 150 to 300 ° C lie.

To one of the preferred embodiments Is it possible between two steps in which solvent is removed one or a mixture of different additives to the partially already of solvent liberated mixture M3) so that a mixture M4) is formed. E is possible for example, the mixture M4) between a first and before a second and further steps in which the removal of the solvent takes place manufacture. It is also possible the mixture M4) only after a second or further step, in which the solvent will be removed. It is also possible to do the process once or repeat several times and between more than two steps in those solvents is removed to add additives and each a mixture M4) or M4 '), M4 ") etc. It is preferred between the first and the second step, in the solvent is removed to add additives and produce a mixture M4).

Additives are not understood to mean the above-mentioned entraining agent. Additives are, for example, waxes, plasticizers, lubricants and mold release agents, pigments, dyes, matting agents, flameproofing agents, antioxidants, light stabilizers and thermal damage stabilizers, fibrous and pulverulent fillers and reinforcing agents and antistatic agents. The additives Kings NEN in pure form solid, liquid or gaseous, or already be used as a mixture of pure substances together. They can also be used in a formulation which facilitates the dosage, for example as a solution, or as a dispersion (emulsion or suspension). A formulation as masterbatch, ie as a concentrated mixture with a melt-compatible thermoplastic polymers, is suitable and in some cases preferred.

workup

According to the invention is in a further step F), the melt obtained in step E) worked up.

In this step can to the melt additives, in the usual for these agents Quantities are added. In this step, of course, too additional thermoplastic polymers or elastomers may be added. According to one of the preferred embodiments Only additives are added to the melt.

To another preferred embodiment no further additives are added to the melt, in particular, if they have already been added in step E).

The optional addition of the additives and possibly other polymers or elastomer can be used in a wide variety of mixing devices respectively. However, preferred are screw machines. among them Both single- and twin-screw extruders are considered. These are preferably provided with one or more vent openings to residual quantities on or over To remove the added materials registered volatiles.

The Melt is subsequently discharged. It can either be the same in a formative unit, e.g. an injection molding unit or as preferred is, crushed, for example granulated. Especially preferred the melt is granulated under water.

The Plant for implementation the method according to the invention may be reactors for the preparation of the rubbers in emulsion and such for preparing the matrix and the mixture M2). alternative it may comprise devices by means of which it is otherwise manufactured Rubbers in emulsion and / or the matrix otherwise prepared or mixture M2) is supplied can be. Of Furthermore, the system includes, in addition to those described above for the implementation of inventive method necessary devices suitable for material handling like gear pumps or screw machines. The material transport However, it can also be done gravimetrically. For the discharge of the melt from the last device for removing solvent, e.g. extruder with inwardly projecting screws particularly preferred. In addition, can the plant of course Devices for recycling and optional for refurbishing solvents removed from the process, Water, matrix or rubber components.

The according to the inventive method available Molding compounds are suitable for the production of moldings, films, Fibers or foams.

V1:

Volumen 1

V2:

Volumen 2

V3:

Volumen 3

Lm:

Lösungsmittel

An example of the inventive method is in the 1 and 2 shown schematically.

V1:

Volume 1

V2:

Volume 2

V3:

Volume 3

lm:

solvent

Claims (14)

Process for the preparation of molding compositions containing a thermoplastic matrix (T) and a rubber (K) dispersed therein, comprising the steps A) preparing the rubber in emulsion, B) isolating the rubber from the emulsion by b1) coagulating the rubber b2) removing C) mixing the rubber obtained under B) with an organic solvent, D) mixing the mixture M1) obtained with C) with a mixture of the thermoplastic matrix with an organic solvent (M2)) E ) Removing the solvent from the mixture M3) obtained under D) and F) working up the product obtained under E), characterized in that the ratio of the viscosity of the mixture M1) to the viscosity of the mixture M2) of 1: 100 to 100: 1 amounts to. Method according to claim 1, characterized in that that the mixture M3) is single-phase. Method according to one of claims 1 or 2, characterized that the rubber is coagulated by shearing. Process according to claims 1 to 3, characterized in that the rubber dispersion obtained under A) is coagulated by means of a device comprising at least one shearing element comprising a stator and a within the Sta having arranged rotor. Method according to claim 4, characterized in that that the shear is below the sintering temperature of the rubber carried out becomes. Process according to claims 1 to 5, characterized that step b2) is multi-level. Method according to one of claims 1 to 6, characterized that step D) is carried out in a static mixer. Process according to claims 1 to 7, characterized that step E) takes place by indirect heat exchange. Process according to claims 1 to 8, characterized that step E) is multi-stage. Method according to claim 9, characterized in that that between two steps in which solvent is removed, Add additive and a mixture (M4) from the partially from solvent liberated M3) and the additive is produced. Method according to one of claims 1 to 10, characterized in that a gum based on a diene rubber is used as the rubber. or acrylate rubbers. Process according to claims 1 to 11, characterized in that a styrene copolymer is used as the thermoplastic matrix becomes. Apparatus for carrying out the method according to at least one of the claims 1 to 12. Device according to claim 13, characterized in that it allows in step D) more M3 mixtures), each in their proportions from rubber to matrix differ from each other and those in the Steps E) and F) are processed separately from each other.