DD158526A5 - METHOD AND DEVICE FOR PREPARING MIXTURES FROM THERMOPLASTIC PLASTICS AND MINERAL OR ORGANIC FUELS - Google Patents

Abstract

In a process for the preparation of mixtures of thermoplastics and mineral or organic fillers, the starting materials to be mixed are mixed under vacuum u. compressed. According to the invention, the object is to be achieved in this case that the plastic-filler mixtures are homogeneous even in powdery state and even without granulation against segregation are stable and processable into products. Furthermore, the rigidity should be significantly higher, but without Sproedigkeit, and it should be possible to achieve strength values that are close to those of pure plastics. Finally, economic benefits are to be achieved. The solution proposed is that the fillers are charged electrically and electrostatically before and / or during the mixing with the plastics. This can alternatively be done with the plastics, for example in an electric field under constant Umwaelzung. The charge remains stable for a long time, so that a separate mixing of pretreatment of Fuellstoffes and intermediate storage is possible. The invention also includes a device with a combined charging and mixing reactor with means for generating violent friction of the contents.

Description

SAPCO System Analysis and Project Control GmbH Hirschburgweg 5 D-4000 Düsseldorf 12 Federal Republic of Germany

Authorized representative

Patent Attorney Office Berlin Frankfurter Allee 28 6 DDR-1130 Berlin

9? Q η λ q 7

SS »'" -WWB * w * ^ **? Ϊ ¹ W ϊ · ϊ * 3 »

title

Process for the preparation of mixtures of thermoplastics and mineral or organic fillers and apparatus for carrying out the process and material produced thereafter

Field of application of the invention

The invention relates to a process for the preparation of mixtures of thermoplastics and mineral or organic fillers, wherein the starting materials to be mixed are mixed under vacuum and compacted.

The invention further relates to an apparatus for carrying out the method with a coolable vacuum container, in which a mixing device is arranged, wherein the supply of starting materials in the vacuum container and the removal of the mixture from the container via the maintenance of the vacuum serving funnels and valves.

Finally, the invention also relates to a .10 .. material in the form of a mixture of thermoplastics and mineral or organic fillers.

With the admixture of mineral or organic fillers to plastics 5 on the one hand a cheapening of the raw material and on the other hand the achievement of desired properties of the subsequent product aims. The particular difficulty is to be seen in the processor of the plastic filler. Mixture to provide a homogeneous, transportable and anti-segregation stable polymer starting material, if no immediate further processing of the mixture is provided. In addition, the mixture must meet as a raw material for further processing, each specified strength requirements. For this purpose, various approaches have been taken so far, which more or less result in a thermal treatment of the plastic base, which causes a melting or softening of the thermoplastic.

Characteristic of the known technical solutions

In the known methods, the components plastic and filler are brought together and mixed by rolling, kneading, plasticizing or extrusion. It is known that the formation of correspondingly large adhesive forces between plastic and filler, the pores of both components must be as free as possible of water and air, because with a smaller distance of the molecular chains between plastic and filler take the van der Waalschen forces, which for a compound Both components provide. If any coagulation-inhibiting gas or moisture envelopes are to be removed, the compounding is carried out under vacuum in single or twin screw extruders in which the materials are continuously conveyed, mixed and compacted. This involves the use of appropriate funnels with degassing devices for component addition

20 required.

Based on this finding, a method for producing a plastic-filler mixture, which has become known from DE-OS 23 34 189. Thereafter, the fillers are first subjected to an intensive pre-drying, this pre-drying is carried out under vacuum, and then the mixture with the plastic also takes place under vacuum to ensure exclusion of moisture. During the mixing process, the process temperature must be controlled so that the plastic particles added in powder form on the surface, so that the filler

ansintertern particle, which means that the resulting agglomerates can no longer segregate afterwards.

The disadvantage of this method is that the procedural effort for the drying of the

Filler and for the sintering process (fishing) in any relation to the achieved adhesion between the plastic matrix and the filler particles and that further the homogeneity of 1G mixture thus produced does not meet the usual requirements. In addition, coloring pigments must be added before the mixing process.

In another known method {DE-OS 23 32 583) plastic and filler are added to each other to achieve the desired mixture with constant kneading. Due to the heat generated during the kneading process as a result of the constant friction, which can be further intensified by v / eitere heat from the outside, the plastic particles melt and mix with the Füllstoffteilchen. This process is carried out until the filler is substantially consumed by the mixing, so that no free or unmixed filler remains and the particles of the polymeric material are consumed by melting at least in the desired Unfang. Depending on the components used, the procedure must be repeated several times.

These and other known methods, which can be summarized due to their physical mode of action under the generic term "thermal procedures", have the disadvantage that the necessary mechanical systems are associated with high investment and operating costs and thereby often allow only low flow rates.

The mixtures made therewith are not homogeneous, i.

the proportion of filler in the individual granules varies. As a rule, inferior properties of the mixture as well as of the later product are due to weak adhesive forces between the plastic matrix and the filler particles. The plastic-filler mixtures tend to brittleness or high Ε-module, simultaneously with increasing proportion of filler to lower strength. Although these effects by the addition of so-called.

Bonding agents overcome or at least limited, but this is associated with high procedural complexity and therefore high costs, so that this possibility is at best reserved for the production of specialty products.

Object of the invention

The general shortage and constant increase in oil prices, which used to be the main raw material for plastic production, makes it necessary to save on the raw material "oil" in the manufacture of plastic products. One possibility for this is the addition of mineral fillers, which has not led to a satisfactory result in the known methods. Therefore, it is the object of the invention, by means of the method according to the invention and the associated device to reduce the expenses for the use of raw materials and at the same time to produce plastic-filler mixtures which have better material properties than the filled thermoplastics produced by conventional methods.

229849

The technical task

The known methods and devices for the production of plastic-filler mixtures provide the mechanical connection of plastic and filler ago by the surface behavior of the plastic is used in its heating. When heat either by generating heat by rolling, kneading, etc. or by means of heat from the outside, the surface of the plastic melts, 'after which the filler connects by fishing or Ansintern with the plastic to granules. However, it has been shown that the compound thus produced is not sufficient to ensure the necessary for the further processing of the plastic-filler mixture homogeneity.

In view of the invention, the technical object of the invention to provide a method for the production of plastic-filler mixtures, which already in powdered! State are homogeneous and even without an elaborate granulation against segregation stable and processable to commercial products. In addition, the materials produced by the process according to the invention should have a significantly higher rigidity, but without the otherwise associated brittleness, and at the same time achieve strength values that are close to those of pure plastic materials and not of the mixtures prepared according to the previously known and previously described methods be achieved. Another object is to provide a suitable apparatus for carrying out the method.

Features of the invention

In the procedure according to the invention, the filler is subjected to an electrostatic charge. Depending on the type of filler, this charge is stable for months. This is also a temporally as local ~ leh separated from the mixing process pretreatment of the filler including about necessary intermediate storage possible.

When plastic and filler are mixed, a charge separation takes place due to the friction which occurs, with the plastic charging with a polarity opposite to that of the filler. However, it may be necessary for certain combinations of filler and plastic depending on their position to each other in the electrostatic series, that the plastic in turn is subjected to a previous charge and thereby receives a charge opposite to the filler.

During the mixing process now forms only due to the opposite charges of the two components of a tight-fitting layer of filler particles around the entire plastic grain; a sintering or angeling of the filler particles on the approximately softened surface of the plastic particles does not take place in contrast to the methods described in the prior art. This is detectable by the fact that in dispersion of the plastic-filler mixture in water, the filler shell separates from the plastic grain, because in the water

- β - / / μ H α μ /

ii.ia » sham *** ¹ Sw ^ *" Sb ^ ώίϊβ

electrostatic binding forces are lifted. Subsequent electron microscopic examination of the "bare" plastic powder grain reveals its almost undamaged surface.

The thickness of the filler shell depends on the desired filler content. The total amount of filler added is bound in the filler shell and does not form its own, separated from the plastic or easily separable from this

Agglomerates or aggregates. As a result, the filler shell produced according to the procedure of the invention is resistant to normal mechanical stresses, e.g. B. by pressure, shock, shear

forces or friction insensitive. In addition, the uniform shape of the filler shell results in a good flowability of the powder desired in further processing.

In terms of the device, the solution of the technical problem mentioned is that

a combined charging and mixing reactor is provided with means for generating violent friction of the parts of the reactor contents, which are arranged downstream of a coolable intermediate volume and this in turn a cooling reactor, wherein a line from the cooling reactor in the charging and mixing reactor is arranged to be recycled.

Alternatively, the vacuum vessel can be preceded by charging reactors, it being possible to arrange an agitator cylinder in the reactor body which consists of an electrically insulating

Material consists of a conductive core and immersed until about half of the reactor body in this. According to one embodiment, the conductive core of the agitator cylinder may be connected to an agitator designed as a multi-arm likewise conductive grid, wherein the respective one-level grid surfaces are tilted by approximately dreigg degrees from the vertical and perpendicular to the lattice planes, respectively on the upper side of the tilted Showing lattice and in the direction of rotation of the agitator, short tips are made of conductive material.

embodiments

In carrying out the erf indungsgeinäßen process, various ways can be taken, as the examples described below can be seen. In the drawing, corresponding embodiments of the devices for carrying out the method are shown, showing:

Fig. 1 is a schematic representation of

Arrangement of aggregates for the charging of the components by friction and their subsequent Ver

mixture,

Fig. 2 is a schematic representation of the arrangement of aggregates for charging the components in an electric field and their subsequent Ver

mixture,

- ¹⁰ - ->? 9 8 AQ

3 is a schematic perspective view of a combined charging and mixing grid,

Fig. 4 is a schematic representation of the on-order of aggregates for charging

the components in an electric field for a continuous implementation of the method,

5 is a cut-away particle of the mixture with plastic core and filler shell,

6 shows the enlargement of a section of the phase boundary in FIG. 5,

7 shows the enlargement of a section of the phase boundary in FIG. 6, FIG.

Fig. 8 column diagram with juxtaposition of mechanical characteristics of a commercial and the material according to the invention.

Example I

20 kg of a filler, for. As chalk, talc or kaolin mica with a humidity of less than 3 wt .-%, v / earth mixed under vacuum in a high-speed mixer at a pressure of 10 millibars, thereby causing an intense friction of the filler particles to each other and

the internal reactor parts comes. As a result, an electric charge of the particles takes place, whereby chalk receives a negative, Kalkum, kaolin and mica a positive charge of several kV. The charges are particularly stable when mixed at short term (eg 0.5 s) peak temperatures in excess of 200 ° C caused either by frictional heat or by additional heating.

Thereafter, the pretreated filler must first cool again. Subsequently, the electrostatically charged filler with the desired amount of plastic, for. B. 20 to 30 kg of polyethylene, polypropylene or other powdered thermoplastics, placed in an evacuated high-speed mixer. The mass is mixed at a pressure of less than one thousand pascals, whereby a certain maximum temperature must not be exceeded, which is to be regarded as an indicator of the friction that has occurred and thus the extent of charge separation of filler and plastic. This maximum temperature is lower than the softening temperature of Kuriststoffes and

25 is based both in their amount

the combination of plastic and filler used and their proportion, for example according to the table below:

^ • s ^ filling substance content 10 % 25 p 40% »-40 % Type of Type of ^ s. Plastic. 85 ⁰ C 95 ⁰ C 130 ⁰ C 130 ⁰ C Fül1 substance polyethylene ooo ooo ooo CO CO CO 100 ⁰ C 105 ⁰ C 95 ⁰ C 140 ° C 135 ⁰ C 140 ⁰ C 145 ⁰ C 140 ⁰ C 145 ⁰ C Talc _e • polypropylene 80 ⁰ C 80 ⁰ C i 80 ⁰ C 80 ⁰ C Cretaceous glittering talc polyvinylchloride chalk

The plastic-filler mixture now present is either stored in powder form, granulated on request or, if required, in an extruder or directly fed to a final product for processing. Granulation and processing must be carried out under vacuum, so that the intensive wetting of the filler by the thermoplastics is not hindered by the air layers or bubbles trapped in cavities or niche irregularities of the rough shell surface, and thus the adhesion forces can advantageously have an effect.

The attraction forces produced as a result of the electrical charge lead to significantly better properties of the filled thermoplastics, in particular to good impact resistance with a low modulus of elasticity.

To carry out the method according to Example I, a device is suitable, as shown in Figure 1.

This apparatus comprises a combined charging and mixing reactor 10 with two hopper 11, 12. The reactor 10 has at its bottom two outputs 13, 14, of which the output 14 is connected to a coolable intermediate volume 15, from which a line 16 to a Cooling reactor 17 leads. From the cooling reactor 17, a line 18 is laid back to the combined charging and mixing reactor 10.

The combined charging and mixing reactor 10 consists of a reactor body 19 and a lid 20, which is electrically isolieri against the reactor body 19

is, preferably through a layer 21 of polytetrafluoroethylene. To produce the required vacuum, the reactor 10 is connected via its lid 20 to a vacuum pump 22. On the lid 20, a pressure indicator 23 is provided.

The lid 20 of the reactor 10 is connected to a high voltage generator 24, which can supply voltages from 0 to 10 kV and is infinitely variable. The reactor body 19 is earthed via a grounding line 25, to which also the mixing unit 26 located in the reactor body 19 is connected. In this case, the grounding of the reactor body including mixer can be interrupted by a switch 27. Further, the reactor body 19 is equipped with a temperature sensor and a charge meter 29. Outside the reactor body 19 around annular cooling coils 30 are arranged.

The feed hoppers 11, 12 are also connected to the vacuum pump 22 and each provided with a pressure indicator 31, 32. Both funnels are each connected to the reactor 10 via vacuum-tight closing members 33, 34.

From the outlet 14 of the combined charging and mixing reactor 10, a line 35 leads to the coolable intermediate volume 15, which is connected to a vacuum pump 36 and has a pressure indicator 37. Outside the intermediate volume is surrounded by annular coolant lines 38,

Coolable intermediate volume and cooling reactor 17 are connected to one another via line 16. The cooling

Reactor 17 is also connected to the vacuum pump 36 and has a pressure gauge 39. The cooling reactor consists of a cooling reactor body 40 with cover 41, wherein the cooling reactor body 40 is internally provided with a non-conductive layer 42, preferably made of polytetrafluoroethylene. Outside the cooling reactor body 40 around annular coolant lines 43 are arranged. Inside is an upright shaft 44, are mounted on the three stirring arms 45, which are still scrapers 46 between the individual stirring arms.

The production of a plastic-filler mixture according to the method described in Example I proceeds in the apparatus shown in FIG. 1 as follows:

One batch of filler, e.g. B. 30 kg of chalk or similar mineral is fed via the evacuated funnel 11 and the product slide 33 in the combined charging and mixing reactor 10. Here, the filler is thoroughly mixed by a high-speed mixer 26, wherein the filler is heated and electrically charged. The charge is constantly monitored via the temperature sensor 28 and the charge meter 29. So that no layer of the filler to be charged deposits on the cover 20 of the reactor, the latter in turn is electrically charged at a temperature of the filler of 70 to 80 ° C from the high voltage generator 24, with a sign opposite to the charge of the filler sign. In contrast, the reactor body 19 and mixer 26 are grounded, the ground in case of need during the charging process on the

£. Z? O ⁴ ^ Ό L ·

Switch 27 can be interrupted so that constant potentials can be established.

If the filler is sufficiently charged, it is conveyed through the outlet 14 via the line 35 into the coolable intermediate volume 15. There, the filler is cooled by running in the cooling coils 38 water before it is conveyed on the line 16 in the cooling reactor 17. During this cooling process, the reactor 10 is cooled by cooling water, which flows in the cooling coils 30, so far that a new batch of filler can be added via the hopper 11 in the reactor 10. Here now the charging of the filler takes place in the same way as described.

The cooling reactor 17 has four times the volume of the reactor 10, so that four charges of filler can be cooled and stored in it. This is because the charging of the filler takes less time than its cooling and the

20 'now the following mixing of filler and plastic.

If the cooling reactor 17 is filled, the lowermost first charge of filler has cooled down to such an extent that a portion thereof can be returned to the reactor 10 via the conduit 18 and the funnel 11. At the same time, a corresponding amount of plastic is added to the reactor 10 via the funnel 12. Here now takes place in the same way as in the electrical charging of the filler intensive mixing of plastic and filler instead. The temperature is constantly monitored by the temperature sensor 28. Has sufficient charge during mixing?

22 9 8 4

completed, the mixing process is terminated. The finished powdered compound can now be fed via the outlet 13 either to a package or to a granulating extruder or another processing machine.

Example II

In a modification of the procedure described in Example I, the charging of the filler or, if necessary, of the plastic can also take place in that the particles are exposed to a correspondingly strong electric field. For this purpose, a correspondingly high voltage is applied between agitator and outer wall of a reactor designed for this purpose. Particularly advantageous is the design of the stirring

plant as a lattice with attached tips, since at the

so-called peak discharge even relatively small voltages sufficient to locally generate a strong electric field. The device is thus comparable to a capacitor, wherein the initially electrically neutral solid state components act as a dielectric.

With a negative voltage applied to the tips of the agitator grid, the tips emit free electrons that are taken up by the filler or plastic molecules. This results in an excess of electrons, whereby the component particles are negatively charged. The particles thus become charge carriers themselves, and there is a virtual displacement of the live grid in the direction of the outer wall of the reactor until all the particles are electrically charged to the desired extent. A discharge of the particles at the counterelectrode,

-18-7 / 3849 L

namely the outer wall, is prevented by / that the inner wall of the reactor vessel is lined with an electrically insulating layer.

If the particles are to be charged positively, the agitator grid and outer wall should be re-folded accordingly. A strong electric field with lattice tips as a (positive) anode releases electrons from the component molecules, which leads to an electron underload, ie a positive charge.

In both cases, the amount of charge introduced is controlled by the magnitude of the voltage and the duration of the process. A uniform charge distribution is generated by continuous slow circulation of the material by means of rotation of the agitator grid.

After charging, the components get into one

Mixed reactor and are there in the same way as in

Example I performed, mixed and then fed to another use.

Compared to the electrical charge in a high-speed mixer according to Example I is associated with the above described in Example II charging in an electric field, the advantage that a cooling, in particular of the filler, after charging is no longer necessary. Thus, the extensive machinery for cooling the material and return to the mixing reactor can be saved. Furthermore, the charging process can be controlled better due to selectable polarity and amount of charge and thus by the attraction forces thus caused

the mixing of plastic and filler achieve a particularly good coating of the plastic grain.

The charging of the components in an electric field is carried out in a device, as shown schematically in Figures 2 and 3.

On a vacuum tank 49 two identically designed reactors 50, 51 are set for the electrical charging, wherein only one of the two reactors is described below. The reactor 50 is evacuated via a vacuum pump 52, wherein the negative pressure via the pressure indicator 53 is controllable. The reactor has a reactor body 54 and an electrically insulated against the body 54 reactor cover 55. The reactor body 54 is in its interior with a

  15 layer 56 lined from an electrically insulating material.

Into the reactor cover 55 is vacuum-tight and electrically isolated, a stirrer cylinder 57 is inserted, which consists of an electrically insulating material and a conductive core 58. As shown in Figure 3, the master cylinder 58 of the agitator cylinder is connected to an agitator 59, which is formed as a two-arm grate 59a, in which the opposing grating surfaces each extend through 30 ° the vertical are tilted. At the crossing points of the individual grids forming the grating 59a, short tips 59b made of conductive material are mounted perpendicular to the grating plane, pointing only on the upper side of the grating 59a tilted by 30 ° and in the direction of rotation of the grating.

A voltage between 0 and 100 kV, which is generated by a continuously variable high-voltage generator 61, is applied to the conductive core 58 and to the outer wall 60 of the reactor body 54 made of conductive material. In this case, the voltage is transmitted to the rotating conductive core 58 by means of a sliding electrode 62.

The reactor 50 is also with. a vacuum-tight feed lock 63 and an output 64, the latter being connected to the vacuum-tight product slide 33 of the vacuum container 4 9. Incidentally, this vacuum container 49 is formed with all its constituents in the same way as the mixing reactor in Example I. It lacks the coolable intermediate volume and the cooling reactor, which are not required in the process described above.

In the apparatus described above, the procedure according to Example II is as follows:

A batch of the required filler is added to the reactor 50 via the vacuum-tight material lock 63. The filler is constantly stirred and agitated by the agitator here. Between the agitator 59 and the outer wall 60 made of conductive material is applied to a voltage of about 80 kV, which is generated by the high voltage generator 61. The polarity of the two conductive components, agitator and outer wall, depends on the desired charge polarity of the filler. Under vacuum, the filler remains in the reactor with constant rotation of the agitator until all particles have reached the desired charge. Thereafter, the filler is over

the outlet 64 and the vacuum-tight product slide 33 in the vacuum tank 49 derived. At the same time an equivalent amount of plastic in the Vakkumbehälter 4 9 is given over the product pusher 34, wherein the plastic may also be electrically charged.

In the vacuum container 49, charge separation now occurs by rapidly mixing both components in the same way as described in Example I, so that the formation of the desired compound occurs due to the electrostatic attraction forces.

Example III

After it is in the above-described examples I and II to devices that allow only a discontinuous, so batchwise production of the desired plastic-filler mixture, the device shown in Figure 4 is set up for a continuous manufacturing process. In this case, the charging of the components must be carried out by means of the procedure described in Example II in an electric field, since then can be dispensed with cooling and thus intermediate storage of the components.

Accordingly, the device for the continuous production of a plastic-filler mixture of Figure 4 consists of a mixing column 65 on which two charging reactors 50, 51 are placed, which correspond to the reactors described in Example II, so that the components charged therein

pass through the locks 66, 67 into the mixing column 65. To produce the required vacuum, the mixing column 65 is connected to a vacuum pump 68, wherein the pressure in the mixing column is controlled via a pressure gauge 69.

The mixing column 65 is formed as a cylinder 70, which merges into a funnel-shaped downwardly tapering cone 71. The inner wall of the cylindrical part 70 of the mixing column 65 is provided with helically upwardly rising grooves 72. Inside the mixing column, a total of three rotors 74 are arranged on a vertical drive shaft 73, one of which is a small diameter in the tip of the cone 71, while the other two with a correspondingly larger diameter at the lower end of the cylindrical portion 70 of the mixing column 65th are attached. The direction of rotation of the rotors 74 is chosen so that the material is conveyed in the ascending guided spiral upwards. Finally, at the base of the cone 71 is still an outlet 75, which is connected to a device 76 for further processing of the plastic-filler mixture, preferably an extruder.

The method proceeds as follows in the apparatus shown in FIG. 4:

The components charged oppositely in the reactors 50 and 51, as described in Example II, are metered into the evacuated mixing column 65 via the locks 66, 67. In the mixing column they meet

29849

On the arranged at the end of the cylindrical portion 70 rotors 74 are mixed there and conveyed in the attached to the inner wall of the cylinder 70 coil upwards. During the upwardly directed migration movement imposed thereby, intensive mixing of the two components, namely plastic and filler, takes place.

The upward promotion of the material in the coil and thus the mixing time are controlled by the dosage of the supply of components in the mixing column 65 and the speed of the rotors 74, so that in each case a corresponding amount of finished compounds in the cone 71 falls. Here it is conveyed with constant further mixing by the arranged in the apex rotor 74 to the outlet 75 and continuously supplied to the standing under vacuum, provided for further processing device. The total residence time in the mixing column 6 5 should be at least five minutes.

² ^ 5 shows an enlarged photo of a single particle 80 of a plastic-filler mixture, which was prepared by one of the methods above-described examples. For better clarity, the particle 80 is cut open and unfolded, so that an insight into the structure of the particle with plastic core 81 and filler shell 82 can be obtained. Here, the sharp dividing line 83 between the plastic core 81 and filler shell 82 is clearly visible. The filler particles are therefore not penetrated into the plastic core or the plastic core is not on or melted and has not mixed with the filler ^v .

This is even more clearly visible in Figures 6 and 7, which show a section of the dividing line 83 between the plastic core 81 and filler shell 82 in two different greatly enlarged 5th Scanning electron micrographs. There are no constituents of plastic 85 between the individual filler particles 84, as would be the case with a sintering or fusing process between plastic and filler. The adhesion between the plastic and the filler thus only goes back to the forces of attraction caused by the opposite electrical charges.

Commercial usability

The plastic-filler mixture produced by the process according to the invention is stable even in powder form against segregation. In general, the mixture is either still granulated, if the customer so wishes, or fed directly to processing to a final product. It is of particular advantage that the end products, in contrast to the method described in the section "prior art" (DE-OS 23 34 189) are subsequently dyeable, which has a favorable effect especially in fibers made from the material of the invention. The adhesive forces between the plastic and the filler caused by the electrical charging of the components also result in significantly better material properties of the filled thermoplastics, which are not achieved by plastic-filler mixtures produced according to the prior art. This is shown by the comparison of the mechanical characteristics shown in FIG.

values of a commercially available polypropylene mixture containing 40% by weight talc with those of a polypropylene blend likewise prepared by the process according to the invention and containing 40% by weight talc. Above all, a significantly lower Ε-modulus and significantly better tear resistance and impact resistance are evident.

The features of the subject-matter of the application disclosed in the foregoing description, in the drawing and in the claim of invention may be essential to each other individually or in any combination for the realization of the invention in its various embodiments.

For this 8 sheets of drawings

Claims (42)

invention claim 1. A process for the preparation of mixtures of thermoplastics and mineral or organic fillers, wherein the starting materials to be mixed are mixed under vacuum and thereby compacted, characterized in that the fillers before and / or during the mixing with the plastics electrically or electrostatically charged become. 2. The method according to item 1, characterized in that the plastics are electrically or electrostatically charged before and / or during mixing with the fillers. - 3! Further processing device (76) is connected. 3. The method according to item 1 or 2, characterized in that the charging of the starting materials - XT - under strong friction of the particles to each other and to the inner reactor parts with resulting frictional heat and appropriate electrical or electrostatic charge is made. 4. The method according to any one of the preceding points, characterized in that the fillers are brought with a humidity of less than three percent by weight and under a pressure of about one thousand pascals to charge. 5 agitator (59) is connected. 5. The method according to any one of the preceding points, characterized in that the charging occurs at short-term peak temperatures above two hundred degrees Celsius, wherein these temperatures are caused by friction and / or heating. 6. The method according to item 5, characterized in that the starting materials are cooled after being charged and before mixing. 7. The method of item 1-6, characterized in that the applied electrical charges are between about one and ten kilovolts. 8. The method according to item 1 or 2, characterized in that the starting materials are charged before they are mixed in an electric field. 9. The method according to item 8, characterized in that the starting materials constantly circulated during charging for uniform charge distribution 10 is connected. (10) a temperature sensor (28) and a charge meter (29) are mounted. 11. The method according to item 1-3 or 8, characterized in that the mixing of the charged substances is carried out under a pressure of about ten millibars. 12. The method according to item 1 - 3 or 8, characterized in that the occurring during the mixing of the starting materials maximum temperature is set lower than the softening temperature of the plastic used. 13. The method according to item 12, characterized in that the maximum temperature is set differently high depending on the type and amount of the plastic and / or the filler (Table page 12}. 14. The method according to at least one of the preceding points, characterized by a further processing of the mixture produced, for example granulation or spinning, under the discharge of the charging exclusion or at least reducing conditions, preferably below 15. The method according to at least one of the preceding points, characterized in that the mixture or the product, for example, the granules or the spun yarn, dyed. 16. A device for carrying out the method according to item 1 and one or more of the other preceding points, with a coolable vacuum container in which a mixing device is arranged, wherein the supply of starting materials in the vacuum container and the removal of the mixture from the container over the maintenance funnel and valves serving vacuum, characterized in that a combined charging and mixing reactor (10) is provided with means (26) for generating severe friction of the parts of the reactor contents, a coolable intermediate volume (15) and this in turn a cooling reactor ( 17), wherein a line (18) from the cooling reactor (17) in the charging and mixing reactor (10) is arranged to be recirculating. 17. Device according to item 16, characterized characterized in that the reactor body (19) and cover (20) of the charging and mixing reactor (10) are electrically isolated from each other by a layer (21) of non-conductive material. 18. The device according to item 17, characterized in that the cover (20) to a high voltage generator (24) is connected, whose output voltages is designed to be infinitely variable. 19. Device according to item 18, characterized characterized in that the reactor body (19) and friction generator (26) are isolated and grounded via a grounding line (25) and that the grounding via a switch (27) is to interrupt. 20. The device according to item 16, characterized in that in the charging and mixing reactor 21. Device according to item 16, characterized in that the coolable intermediate volume (15) can be evacuated and for this purpose to a vacuum pump (36). 22 9 8 4 9 22. The device according to item 16, characterized in that the cooling reactor (17) has a multiple volume, preferably four times the volume of the charging and mixing reactor (10). 23. Device according to item 21 and 22, characterized in that the cooling reactor (17) is evacuated and for this purpose connected to the vacuum pump (36). 24. Device according to item 16, characterized characterized in that the reactor body (40) of the cooling reactor (17) is provided in its interior with a layer (42) of non-conductive material. 25. Device according to item 16, characterized characterized in that in the cooling reactor (17) an upright, rotating under the action of a drive shaft (44) is arranged and that on the shaft stirring arms (45) are fixed, between which scrapers (4 6) are located. 25 vacuum. 26. Apparatus for carrying out the method according to item 8, comprising a vacuum container in which a mixing device is arranged, wherein the supply of starting materials into the vacuum container and the removal of the mixture from the container via the maintenance of the vacuum serving fittings, characterized that the vacuum vessel (4 9) charging reactors (50, 51) are connected upstream. 27. The device according to item 26, characterized in that each charging reactor (50, 51) is evacuated and for this purpose connected to a vacuum pump (52). 28. The device according to item 26, characterized in that the reactor body (54) and cover (55) of the charging reactors (50, 51) are electrically isolated from each other. 29. The device according to item 26 - 28, characterized in that the reactor body (54) consists of conductive material, but is lined in its interior with a layer (56) of electrically insulating material. 30 reactor body (54) immersed in this. 30. Apparatus according to item 26, characterized characterized in that from the cover (55) forth in the reactor body (54) a stirrer cylinder (57) is arranged, which consists of an electrically insulating material with a conductive core (58) and to about half of 30 will be. 1O. Method according to item 8 and 9, characterized characterized in that the amount of charge introduced is controlled by the magnitude of the voltage and the duration of the process. 31. The device according to item 30, characterized in that the conductive core (58) of the agitator cylinder (57) formed on a multi-arm also conductive grid (59 a) 32. Device according to item 31, characterized in that each forming a plane grid surfaces are tilted by about thirty degrees from the vertical. 33. Device according to item 32, characterized in that perpendicular to the lattice planes, each on the upper side of the tilted grid (59a) and in the direction of rotation of the agitator (59) pointing, short tips (59b) are made of conductive material. 34. Apparatus according to item 29 and 30, characterized in that on the outer wall (60) of the reactor body (54) and the conductive core (58) a voltage of up to one hundred kilovolts applied, which generated by a continuously variable high voltage generator (61) ' becomes. 35. Device according to item 26, characterized in that the charging reactors (50, 51) are vacuum-tightly connected to the vacuum container (49) via locks. 36. Device according to item 26, characterized in that the discharge (75) of the vacuum container (65) directly to one of 37. Device according to item 36, characterized in that the mixing column (65) formed as a vacuum container consists of a cylinder (70) which merges into a funnel-shaped tapered lower part (71), wherein the cylindrical part (70) on its inside is provided with helically rising grooves (72). 38. The device according to item 37, characterized in that at a center of the mixing column (65) standing, vertically arranged drive shaft (73) a plurality of rotors (74) are mounted, of which a rotor (74) in the top of the funnel ( 71) while the others are located in the lower portion of the cylindrical member (70). 39. A material in the form of a mixture of thermoplastics and mineral or organic fillers, prepared by the process according to item 1 or 2, characterized in that the mixture constituents (80) consist of a core (81) of thermoplastic material and a filler shell ( 82). 40. The material according to item 39, characterized in that the filler shell (82) alone due to the by the opposite electrical charges of plastic and filler be - 3fr - attracted to the plastic core (81). 41. The material according to item 40, characterized in that the surface of the plastic core (81) is unhurt under the accumulated Füllstoffteilchen. 42. The material according to item 40, characterized in that the filler shell (82) is mechanically stable.