MXPA00002423A - Process for the continuous production of rubber powder and apparatus for carrying out the process - Google Patents

Abstract

The mixture of aqueous filler dispersion (e.g. carbon black) and rubber latex e.g. styrene-butadiene latex, is passed along a pipe and mixed with a coagulant. The pipe includes a throttle of variable cross section and one or more points of introduction. The throttle causes a pressure drop in the mixture, exceeding 0.5 bar. An Independent claim is included for equipment carrying out the process. This includes the pipe (1) and supply points (2, 4) for rubber latex suspension (3) and filler (5). A feeder (10) for coagulant (11) and a throttle valve (6) are included. Preferred features:To prevent deposition at the throttle, its cross section is continuously varied during continuous operation. The mixture passes through the throttle before addition of coagulant. Alternatively a mixture of rubber latex, filler and coagulant is passed through the throttle. Precipitated rubber particles are coated and passed through a further point of throttling in the pipe. A coating agent supply (14) is included. An additional throttle (16) adjusts flow cross section. A further supply point introduces acid medium for pH control of the liquid mixture.

Description

METHOD FOR THE CONTINUOUS MANUFACTURE OF RUBBER POWDERS AND DEVICE FOR CARRYING OUT THE METHOD Field of the Invention The present invention relates to a method for the continuous manufacture of rubber powder containing filler material, in which a suspension of filler and rubber is mixed in water, which is conducted through a tube and it is mixed in the tube with a coagulating agent and rubber particles containing filler material are precipitated.

BACKGROUND OF THE INVENTION The manufacture of rubber mixtures is carried out according to the state of the technology from crude rubber that exists in the form of a bullet under a high effort of time, energy and personnel. The crushing of bales and mixing with additives is a high effort and high costs. To change, the use of rubber powders susceptible to shifting offers the possibility to manufacture and manufacture rubber mixtures in a simple and fast way. REF .: 32942 From the patent US 4 265 939 a method for the continuous manufacture of rubber powders is known, however, in which the rubber powder is mixed in a tube with a relatively narrow cross section with a coagulation agent An efficient mixture of both components must be carried out due to a turbulent current inside the narrow tube. The coagulated rubber material is then guided to a tube with a wider cross section. In this tube, a polymer is added as a coating agent to the liquid mixture. This known method leaves much to be desired with respect to the efficient mixing of the components. In addition, disturbing sediments or wall agglomerations, respectively, which change the current conditions, particularly occur in the tube with the narrowed cross-section. Therefore, the properties of the products manufactured according to this method are not reproducible, and these products have also disadvantageous and undesirable properties due to the changing current conditions during manufacture. Basically it is also known from DE 37 23 213 C2 and DE 37 23 214 C2 that within the scope of a method for the continuous production of rubber powders containing filler material, the rubber material can be mixed continuously with the material of stuffing inside a tube. However, you can not find a concrete revelation to carry out this method in any of the two documents. Furthermore, methods for manufacturing rubber powders containing filler material that are executed in a staggered manner or that are carried out discontinuously are known. In these methods, a suspension containing filler material is generally combined with a latex in the presence of a pre-ipoting agent, and then the reaction of the mixture is allowed to terminate in a vessel. These known methods disadvantageously require a high effort of devices and time. Such a discontinuous method is described, for example, in DE 28 22 148 C2. Contrary to what has been described above, the present invention has as its task to provide a method for producing a rubber powder containing filler with reproducible properties without problems and with low stresses and avoiding the disadvantages mentioned above.

Description of the Invention An object of the present invention is a method for the continuous production of rubber powder containing filler material, in which a) dispersions of filler material and rubber suspensions are mixed; b) the liquid mixture is conducted through a tube, it is mixed with at least one coagulating agent and the rubber powder containing filler is precipitated: c) the liquid mixture is conducted through a tube with at least one choke place with a variable choke cross section; and d) the cross-section of throttling is adjusted with the measure that the reduction of pressure in the liquid mixture obtained with the place of rangulation is greater than 0, 5 bar. It is within the scope of the present invention that the liquid mixture contains at least one liquid medium, in particular water. Preferably a suspension is used, suitably an aqueous suspension of the filling material, or, respectively, it is added to the rubber material. The rubber material is suitably used as a rubber latex - as a rubber solution and / or as a rubber solution. as an aqueous emulsion of a rubber solution. The rubber material can be a synthetic rubber and / or a natural rubber. According to a preferred embodiment of the present invention, a styrene-butadenium copolymer is used as the rubber latex. It is within the scope of the present invention to employ one or more filler materials. For example, carbon black is used as a filler. It is within the scope of the present invention to add to the rubber material an aqueous suspension of carbon black, in particular an aqueous suspension of 2 to 7% by weight of carbon black. The range of granule sizes of the rubber powders obtained according to the present invention is generally between 0.05 and 10 mm, and in particular between 0.5 and 2 mm. The rubbers in the form of powder contain between 20 and 250 phr, in particular between 50 and 100 phr of filler material (phr: parts per hundred parts of rubber) which, if necessary, was partly or completely modified on the surface the use of the organosiliceous compounds known in the rubber sector according to formulas (I), (II) and (III) before the method according to the present invention. As rubbers the following species have been shown to be suitable either individually or in a mixture: natural rubber, styrene-butadenium rubber in emulsion with a styrene part between 10 and 50%, butyl rubber and acrylic nitrile, butyl rubbers, t polymers of ethylene, propylene (EPM) and non-conjugated dienes (EPDM), butadiene rubber, rubber of est i reno-butadenj or, manufactured according to the solution polymerization method, with styrene contents of 10 to 25%, as well as contents of 1,2-vinyl components from 20 to 55% and isoprene rubbers, in particular 3,4-polyisoprene. In addition to the aforementioned rubbers, the following elastomers are also suitable, either individually or in a mixture: carboxyl rubbers, epoxy rubbers, trans-polypentenamer, halogenated butyl rubbers, 2-chloro-butadiene rubbers, vinyl acetate copolymer. ethylenic, epichlorohydrin, optionally also chemically modified natural rubber, such as, for example, epoxidized types. As fillers, in general, the carbon blacks known for the manufacture of rubber and white fillers of a synthetic nature, such as, for example, precipitated silicon acid or natural fillers, such as, for example, chalk, are also used. siliceous, clays, etc. Particularly suitable are the blacks of smoke as they are used in general in the manufacture of rubber. These include furnace carbon blacks, gas and lamp blacks with a degree of iodine adsorption from 5 to 1000 m2 / g, a CTAB number from 15 to 600 m2 / g, an adsorption of DBP from 30 to 400 ml / 100 g and a DBP number of 50 to 370 ml / 100 g in an amount of 5 to 250 parts, in particular 20 to 150 parts in relation to 100 parts of rubber, in particular 40 to 100 parts . Also suitable are silica filling materials known from the rubber sector of a synthetic or natural origin, in particular, precipitated silicon acids.

These generally have a surface area of N2 determined according to the known BEJ method, from 35 to 700 m2 / g, a CTAB surface of 30 to 500 m2 / g and a DBP number of 150 to 400 ml / 100 g. The product according to the present invention contains these silicon acids in an amount of from 5 to 250 parts, in particular from 20 to 100 parts in relation to 100 parts of rubber. In the case of natural white fillers, such as clays or siliceous chalk with an N2 surface area of 5 to 350 m2 / g, an amount of 5 to 350 parts is used in relation to 100 rubber parts. Also suitable are powders containing a mixture of one or more filler materials mentioned above. In addition to the unmodified filler materials of the abovementioned type, fillers modified in the manufacture of the rubber powders claimed in the present application are also used, if appropriate. The part of the unmodified filler materials depends on the mixture to be specifically manufactured. In each case, the total amount of the filling materials is from 20 to 250 phr. This generally consists of 100%, in particular 30 to 100%, preferably 60 to 100% of the unmodified filler materials; silicon acid and / or carbon black. For the modification of the surfaces, organosiliceous compounds are generally used, according to the general formulas: p ^ n (RO) 3-nS ± - (Alk) m- (Ar) pJ q [B], (I) R2n (RO) 3-nS ± - (Alk), or (II) R1n (RO) 3-nSl - (Alkenyl), (III) in which it means: B -SCN, -SH, -Cl, -NH2- (when q = 1) or Sv (when q = 2) R and P.1: an alkyl group of 1 to 4 carbon atoms, branched or unbranched, the phenyl moiety, in which all the radicals R and R1 may each have the same or a different meaning, preferably an alkyl group, a C1-C4-alkyl group, Cl-C4-alkoxy, branched or unbranched n: 0; 1 or 2, Alk: a straight or branched bivalent hydrocarbon radical of 1 to 6 carbon atoms, m: 0 or 1, Ar: an arylene test with 6 to 12 carbon atoms, p: 0 or 1 with the measurement which p and m do not mean 0 at the same time, x: a number from 2 to 8, alkyl: a monovalent, non-straight or branched hydrocarbon radical of 1 to 20 atoms, preferably with 2 to 8 carbon atoms alkenyl: a hydrocarbon radical monovalent, non-straight or branched with 2 to 20 atoms, preferably with 2 to 8 carbon atoms. The modified filler materials which are used according to the present invention are described, for example, in EP-B 0 442 143, in EP-B 0 177 674, and, in particular, in the form of granules. in EP-A 0 795 579 (white filler materials) or, respectively in EP-B 0 519 188 (carbon black). The bis (alkoxysilyloalkyl) -oligosulfanes of the bis (trialkoxysilylpropyl) tetrasulfan and -disulfan types were also shown to be suitable for the pre-modification or addition of the suspension of filler material. The modified filler materials known from the patent applications or patents, respectively, and the organosiliceous compounds indicated therein are incorporated explicitly as part of the compounds claimed in the present patent application. The rubber powders according to the present invention include, in addition to the aforementioned filling materials, in particular, auxiliary processing and vulcanization agents with zinc oxide, zinc stearate, stearic acid, polyalcohols, polyamines, resins, waxes. , anti-oxidant softening oils against heat, light or oxygen or ozone, reinforcing resins, flame protection agents such as, for example, Al (OH) 3 and Mg (OH) 2, pigments, different chemical crosslinking agents and accelerators and, given the case, sulfur in the conventional concentrations of rubber technology, preferably sulfur in modifications mixed with surfactants, as it is commercially available.

The determination of the grain size is obtained from the suspension of filling material. In a particularly preferred form of the method according to the present invention all the solid materials used are before the precipitation of the rubber particles from the < 50 mm, preferably from < 10 mm. If appropriate, the formation of agglomerates may occur due to the manufacturing method, which, however, do not have a negative influence on the processing behavior. It is also an object of the present invention, a method for the manufacture of fine particle rubber powder containing filler material by precipitation from mixtures containing water, in a tube provided in suitable places with throttling valves, which contain filling material or materials (carbon black and / or silicon filler) of fine particles, if appropriate, modified with organosiliceous compounds, water-soluble salts of a metal of the groups lia, Ilb, Illa and VIII of the system periodic of the elements, and a rubber latex or the aqueous emulsion of a rubber solution, if necessary, in the presence of a solvent, characterized by the fact that a) it is mixed > 50% by weight, but less than 100% by weight of the expected amount of a fine particle filling material, preferably in the form of an aqueous suspension with a content of 2 to 15% by weight in water, optionally with a quantity provided for the modification of the surface of filling material, of one or more organosilioe compounds according to the formulas (1), (II) or (III) in an amount of 0.1 to 20% by weight in relation to the filler material, in particular, if it is a silicon filler. preferably precipitated silicon acid, and / or > ^ 50% by weight, but less than 100% by weight of a modified filler material on the surface by at least in part with one or more organosilicon compounds (formulas (1), <II) or (III)), in particular in the presence of an emulsifying agent with a rubber latex or an aqueous emulsion of a rubber solution, and the pH value of the mixture is reduced (in a first step) to a value in the range from 7.5 to 6.5, in particular by the addition of a Lewis acid; b) the remaining part (dividing penis) of the aforementioned fine particulate filler material is added, optionally, with the remaining amount of organosilicon compounds according to formulas (I), (II) or (III) intended for modifying the surface of filler material, in the form of a suspension, and the pH value is reduced, in particular by the addition of a Lewis acid to a value in the range of < 6.5 to "5, preferably" 5.5 so that the rubber in the mixture is completely precipitated together with the filling material (second stage), c) the precipitated solid material is separated with known measures, d) the rubber is washed, if necessary, and e) the same is dried. The organosiliceous compounds are used in particular under the use of silicon filler material, preferably silicon acid. The precipitation method is generally carried out at room temperature in particular between 20 and 80 ° C inside the tube which is preferably provided with several entry places. The method is carried out in adaptation to the known measures of DE 198 58 706.6. In the method which is used according to the present invention, a tube with a circular cross-section is preferably used. The tube diameter is, for example, from 10 to 30 mm. Preferably the total length of the tube is from 1 to 3 m, and most preferably from 1.5 to 2.5 m. According to the present invention, the cross section of the tube is reduced at least in one throttling location. Preferably, the diameter of the tube in front of the throttling site is equal to the diameter of the tube behind the throttling site. It is within the scope of the present invention that an adjustable throttle element is disposed at the throttling site. This is preferably a valve, and more preferably from a clamping valve with an elastic insert body. According to a highly preferred embodiment of the present invention, at least one throttle element is adjusted and adjusted with the aid of a drive device. The variable cross section reduction according to the present invention at the throttling site serves so that the continuous method can be carried out always so that the pressure drop that is achieved at the throttling site is always greater than 0, 5 bar In other words, the throttle cross section is adjusted with the throttle element during the execution of the continuous method in an appropriate manner, always so that the pressure in front of the throttle location or in front of the throttle element, respectively, is at least 0. , 5 greater than behind the place of rangulation or behind the throttle element, respectively. It is within the scope of the present invention that the pressure drop achieved with the throttling site within the liquid mixture has a maximum of 6 bar. Preferably, a pressure drop of 0.5 to 3 bar, and most preferably 0.8 to 2.5 bar, is achieved at the throttling site. On the basis of the throttling, a surprisingly optimal mixture of the components that are conducted through the throttling site is achieved. It is within the scope of the present invention that the cross-section of the tube is widened again in the direction of the backstream of a throttling site according to the present invention. According to a highly preferred embodiment, the cross-section of throttling is varied during the execution of the continuous method for the elimination of sediments in the throttling zone. Sediments in the throttling zone means in particular sediments or wall agglomerations, respectively, briefly in front of the throttling site and briefly behind the throttling site, as well as in the rerouting element. Thus, if sediments or wall agglomerations are determined, respectively, in the throttling zone, the cross-section of throttling is preferably varied depending on this fact. The adjustment of the choke cross section is carried out automatically. According to a very preferred embodiment, a constant pressure drop at the throttling site is always maintained or adjusted, respectively, within the scope of the present invention. Yes, due to. In the case of sediments or wall agglomerations, respectively, the pressure drop in the throttling site is changed, the throttling cross-section preferably being adjusted, until the desired constant pressure drop is achieved again. For the components that are used for the manufacture of the fine particle rubber powder, a surprisingly efficient mixture is achieved by means of the throttling according to the present invention so that the final products with the desired characteristics can be manufactured without problems. For this purpose, it also contributes that the sediments or wall agglomerations, respectively, which would change such current conditions in a disadvantageous manner, can be prevented in a simple manner according to the present invention, and in this way reproducible products can be obtained. According to one embodiment of the present invention, the liquid mixture of rubber latex and suspension of filler material is conducted before the addition of a coagulation agent through a tube with a throttling site according to the present invention. invention. In this embodiment, an efficient mixing of the rubber latex and the filling material takes place immediately behind the throttling site. According to another embodiment of the present invention, a liquid mixture of rubber latex is conducted., of filling material and of coagulation agent through one of the above-mentioned throttling sites. It is within the scope of the present invention to provide a first place of rangulation through which a liquid mixture of rubber material and suspension of filler material is conducted and then a coagulation agent is added and then it is conducted again. liquid mixture through a second place of strangulation. Immediately behind this second throttling site an efficient mixing of rubber latex, filler material and coagulating agent takes place. In accordance with a preferred embodiment of the present invention both the cross-section of throttling of the first place of throttling as the cross-section of throttling of the second throttling site so that the pressure drop within the liquid mixture that is achieved with the respective throttle location is greater than 0.5 bar and has a maximum of 6 bar.

According to a very preferred embodiment, which has a particular meaning within the scope of the present invention, the precipitated rubber particles are coated with a coating agent. It is within the scope of the present invention that the addition of the coating agent to the coagulated rubber material is carried out. Suitably, a filler material for rubber is used as the coating agent. In this case, the filling material that was mixed at the beginning of the method with the rubber material can be used. However, it can also be another filler material. According to a preferred embodiment of the present invention, the liquid mixture is conducted with the aggregate reversing agent through an additional location of trangulation within the tube. Suitably, the pressure drop also in this throttling location is greater than 0.5 bar and has a maximum of 6 bar, and is preferably 3 bar. According to a preferred embodiment of the present invention, the liquid mixture is conducted through a total of three throttling sites within the tube. In this embodiment, the rubber material and the filler material are first mixed and the mixture is passed through a first place in the field. A coagulation agent is added to the section of pipe that follows it and the resulting liquid mixture is passed through a second choke point. In the pipe section that follows, then the precipitation of the rubber particles takes place. and then a coating agent is added in this tube section. The mixture with the coating agent is then passed through a third throttling site. Preferably, the pressure drop is at each of the three throttling locations greater than 0.5 bar. Appropriately, at least two, and preferably all three, choke locations are formed as described above with respect to a first choke site.

According to a second preferred embodiment, a total of two throttling locations within the tube are provided. In this embodiment, a rubber material, a filler material and a coagulation agent are first mixed and this mixture is conducted through the first choke point. In the section of pipe that follows the first place of rangulation, then the precipitation of the rubber particles takes place and then a coating agent is added. The mixture with the coating agent is then conducted through a second throttling site. Preferably, the throttle cross section is adjusted at each throttle location with the measure that the pressure drop inside the liquid mixture is at each of the throttle locations is greater than 0.5 bar and has a maximum of 6 bar . Appropriately, the two choke locations are shaped as described above with respect to a first choke place. Also an object of the present invention is an arrangement for carrying out the method according to the present invention according to claim 7. Claims 8 and 9 claim preferred embodiments of the arrangement according to the present invention.

The present invention is based on the understanding that a rubber powder containing a filling material with reproducible properties can be obtained in a way that requires less effort, if one works with the type of continuous method according to the present invention. . With the throttling sites according to the present invention a surprisingly efficient mixture of the components used here is achieved (rubber material, filling material, optionally: coagulation agent) so that in the aftermath of mixing develops the desired reaction completely and without problems. In particular, the perfect mix of the components here in question is generally very problematic for. for example, achieve a homogenous incorporation of the filling material into the rubber. With the variable choke according to the present invention this mixture is achieved in a surprisingly efficient and safe manner by the person skilled in the art. With the help of the throttling elements, preferably throttle valves, a specific, turbulent current is generated on the basis of the pressure drop according to the present invention and, therefore, a very homogeneous mixture is achieved in such a way that also result in homogeneous final products. This was not possible in the known methods mentioned at the beginning of this description. In addition to the optimum mixing of the components it is achieved with the throttling according to the present invention further that the sediments or agglomerations in the throttling zone can be avoided in a surprisingly efficient manner by changing the throttle cross-section. By means of adjusting the pressure drop with the aid of variable throttle cross sections, obstruction-resistant throttling sites which function as optimum mixing elements are thus obtained according to the present invention. With the method according to the present invention, rubbers in the form of powder can be manufactured which can already have all the auxiliary rubber components. In addition to these filler materials, these can be sulfur, vulcanization accelerators, activators as well as protector against rubber aging. These rubber auxiliary components can be added without problems during the execution of continuous method to the liquid mixture, and then these rubber auxiliary components are distributed very homogeneously in the final products in powder form. In contrast to the known methods, it is also possible in a very easy way, subsequent treatments, in particular, the coating of the rubber particles providing in accordance with the present invention another element of rangulation and contributing the pressure drop adjusted for this The throttle element also ensures that the coating agent is efficiently mixed with the liquid mixture and, therefore, that the particles are coated uniformly and in a safe operation. With the continuous method mode in the tube according to the present invention, essentially higher yields per unit time are achieved compared to a batch mode. The residence periods of the liquid mixture within the tube according to the present invention are relatively small.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, the present invention is described in detail by means of an illustrative drawing showing only one embodiment. It is shown in a schematic illustration in: Figure 1 a first embodiment of an arrangement for carrying out the method according to the present invention, Figure 2 a diagram for the arrangement according to "Figure 1, in which the pressure is schematically illustrated as a function of the length of the tube, or of the period of permanence of the tube, respectively, and Figure 3 a second embodiment of the object according to Figure 1.

Description of the Figures Figures 1 and 3 show an arrangement for the continuous manufacture of a rubber powder containing filler material. The arrangement consists of a tube 1 for driving through it a liquid mixture containing rubber and for the precipitation of rubber particles. Both in the exemplary embodiment according to FIG. 1 and in the exemplary embodiment according to FIG. 3, a supply device 2 for a rubber material 3 and a delivery device 4 are connected to the principle of the tube 1. for a filling material 5. The rubber material may be rubber latex, preferably styrene-butadenium. In the filling material it is an aqueous suspension of carbon black. In the embodiment according to the Fig. 1 the liquid mixture of rubber material 3 and filler material C is led first through the first throttle element 6. The throttle cross section of this first throttle element 6 is always adjusted so that the fall of pressure that is achieved within the liquid mixture in the place of throttling is greater than 0.5 bar. Of course it is understood that corresponding pressure sensors are provided which are not shown in the Figures. By means of the pressure indicators 7, B, 9 the respective pressure conditions that exist in the individual tube sections can be read in the embodiment according to FIG. Preferably the method is carried out so that a constant pressure drop during continuous method execution is always adjusted in the first throttle element. Correspondingly, the choke cross section is adjusted so as to maintain this constant pressure drop. In accordance with a preferred embodiment, the first throttle element 6 is automatically reset. The first throttling element 6 can be embodied as a clamping valve in this embodiment. Preferably and in the exemplary embodiment according to FIG. 1, the tube section in front of the first throttle element 6 has the same cross section as the tube section behind the first throttle element 6. By means of the throttle in FIG. the first throttle element 6 performs a particularly efficient mixture of the rubber material with the filler material. Via a delivery device 10 a coagulation agent 11 is added to the liquid mixture within the tube 1. This liquid mixture is then conducted through a second throttle element 12 having a throttle cross-section which is adjusted so that the pressure drop that is achieved within the liquid mixture in the choke place is greater than 0.5 bar. Correspondingly, the throttling cross-section is also adjusted by means of this second throttle element 12 during the method, always in such a way that a constant pressure drop is maintained. Preferably the readjustment of this second throttle element 12 is also carried out in a manner that is also correct. automatic depending on the pressure drop measured. Preferably and in the exemplary embodiment according to Fig. 1, the tube diameter in front of the second throttle element 12 corresponds to the tube diameter behind the second throttle element 12. Behind the second throttle element 12, the coagulating agent 11 is mixed with the liquid mixture in a surprisingly efficient manner. In the tube section 13 immediately following the second throttle element 12, the strongly mixed reactants react and the rubber particles are precipitated in this luaar.

Preferably and in the exemplary embodiment according to FIG. 1, another delivery device 14 for a coating agent 15 is provided. In the exemplary embodiment, the coating agent 15 can coincide with the filling material 5, With this coating agent 15, the rubber particles which have been precipitated before must be coated. The liquid mixture with the coating agent 15 is conducted in the exemplary embodiment according to FIG. 1 through an additional throttle element 16. Also in this additional throttle element 16 the throttle cross section is adjusted under the as the pressure drop that is achieved by the place of throttling within the liquid mixture in the place of throttling is greater than 0.5 bar. Preferably, a constant pressure drop is also always set here and this pressure drop is readjusted as in the throttle elements 6, 12 described above, preferably automatically. Suitably, the pipe diameter in front of the additional throttle element 16 corresponds to the pipe diameter behind the second additional throttle element 16. Behind the additional throttle element 16 the coating agent is mixed with the liquid mixture in a surprisingly efficient manner . In the tube section immediately following the additional rasgulation element 16, then the coating of the rubber particles takes place. The precipitation product 17 is extracted at the end of the tube in the form of coated rubber particles. A separation of the coated rubber particles containing filler material from the liquid phase, or from the aqueous phase, respectively, is then carried out appropriately and then a drying of the powder is preferably carried out. of rubber. A fine particle rubber powder with reproducible properties is obtained. In FIG. 2, the pressure P inside the tube 1 against the length of the tube (in meters), or against the period of permanence of the liquid mixture in the tube, is scaled for a disDositive according to FIG. in seconds). The length of the tube is measured here from the first throttle element 6. Accordingly, a tube with a length of 2.5 m (measured from the first throttle element 6) is used in the exemplary embodiment. The diameter of the tube is in the exemplary embodiment of. 25 mm. In the diagram according to Fig. 2 it can be read that the pressure drop ÜPi in the first throttle element 6 is 1.5 bar. The pressure drop U2 in the second throttle element 12 is in the exemplary embodiment of 2 bar and the pressure drop U3 in the additional throttle element 16 is 1 bar, since, in this embodiment, the pressure of the liquid mixture inside the tube 1 by a total of an initial pressure of 4.5 bar at 0 bar. Preferably the maximum initial pressure is 6 bar. According to a preferred embodiment, the pressure drop Pi in the first throttle element 6 is between 0.5 and 2.5 bar, preferably between 1 and 2 bar. Preferably the pressure drop ΔP2 in the second throttle element 12 is between 0.5 and 3 bar, preferably between 1.5 and 2.5 bar. Suitably, the pressure drop AP3 in the additional reaming element 16 is between 0.5 and 2 bar, preferably between 0.5 and 1.5 bar.

In Fig. 3 another embodiment of a device according to the present invention is shown. Via the delivery device 2, rubber material 3 is supplied in the form of a 20% by weight latex made from a styrene-butadiene copolymer. Via the delivery device 4, filling material 5 is supplied in the form of a 3% by weight carbon black suspension to the tube 1. For the preliminary mixing of the rubber material 3 with the filling material 5 the mixture is first conducted liquid through an arrangement of guide plates 18, and then a coagulating agent 11 is supplied to the tube 1 via the delivery device 10 in the form of a 20% by weight alumina sulfate solution. The liquid mixture is then conducted with the coagulation agent through the first leveling element 6. The coagulation cross-section of this first ion element 6 is adjusted so that the pressure drop achieved in the Liquid mixture is greater than 0.5 bar. An efficient mixing of the rubber material, the filling material and the coagulation agent takes place behind the first throttle element 6. Via the delivery device 19, an acid 20, preferably a 10% by weight sulfuric acid solution, is supplied to the tube 1, thereby adjusting a pH value between 1 and 10. It is within the scope of the present invention to adjust a value pH between 2.5 and 9. Preferably a pH value greater than 6 is set. With the pH indicator 21 the pH value can be controlled. By adjusting the pH value, the size of the coagulated or filled rubber particles can be regulated, respectively. In the tube section immediately following the delivery device 19, precipitation of the rubber particles takes place. Via the delivery device 14, a coating agent 15 is supplied. The liquid mixture with the coating agent 15 is then passed through the additional throttle element 16. Behind the additional throttle element 16, a very efficient mixing takes place and, therefore, an efficient coating of the rubber particles. After this, the final precipitated product 17 is extracted in the form of the fine-particle, coated rubber particles and present in an aqueous phase. The rubber particles are then separated from the aqueous phase, and then, preferably, the rubber powder is dried. In the exemplary embodiment according to FIG. 3, the total length of the tube is 1.5 m. The pipe section between the supply devices 2 and 4 and the first throttle element 16 has a length of 0.25 m. The length of the tube section between the first element of rangulation i? and the additional throttle element 16 is 1.0 m and the section of pipe that follows behind the additional throttle element 16 has a length of 0.25 m. The diameter of the tube 1 outside the throttle elements 6, 16 is 15 mm.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property:

Claims (10)

1. A method for the continuous manufacture of rubber powder, which contains filling material from dispersions of filling material and rubber latices: characterized by the fact that a) the liquid mixture is conducted through a tube, mixes it with at least one coagulation agent; b) the tube includes at least one throttling site with a variable throttle cross section and optionally one or more inlet locations: and c) the throttle cross section is adjusted as the pressure reduction in the mixture liquid that is obtained with the place of rangulation is greater than 0.5 bar.

2. The method according to claim 1, characterized in that the cross-section of throttling is varied during the execution of the continuous method for the elimination of sediments in the throttling zone.

The method according to any of claims 1 or 2, characterized in that the liquid mixture of rubber latex and suspension of filler material is conducted before the addition of a coagulation agent through the place of strangulation.

4. The method according to any of claims 1 or 2, characterized in that a liquid mixture of rubber latex, filler material and coagulation agent is conducted through the throttling site.

5, The method according to any of claims 1 to 4, characterized in that the precipitated rubber particles are coated with a coating agent.

6. The method according to the claim

5, characterized in that the liquid mixture is conducted with the coating agent added through a choke point

• additional inside the tube.

7. A. device for carrying out the method according to any of claims 1 to 6, characterized in that a tube is provided for the passage of a liquid mixture containing rubber and for the precipitation of rubber particles, in which At the beginning of the tube, at least one supply device for rubber material is connected as well as a supply device for filling material, in which at least one delivery device for a coagulation agent is connected to the tube, and, wherein at least one throttle element for the variable adjustment of the throttle cross-section is provided in the tube.

fi The device rfft according to claim 7, characterized in that, in the current direction, at least one supply device for a coating agent is connected to the tube behind the throttle element.

9. The device according to claim R, characterized in that, in the current direction, an additional throttle element for variable adjustment of the throttle cross section is provided behind the supply device for the reversing agent. .

10. The device according to any of claims 7 to 9, characterized in that the tube is connected to at least one delivery device (place of entry) for an acidic agent for adjusting the pH value in the mixture 1 what a way