METHOD FOR PRODUCING A STABILIZER COMPOSITION, AND STABILIZER COMPOSITION PRODUCED USING SAID METHOD

Abstract

A method for producing a stabilizer composition for a polymer and a stabilizer composition produced by the method. At least one carboxylic acid is reacted with at least one metal compound, such as at least one metal hydroxide and/or at least one metal oxide and/or at least one metal carbonate, thereby forming a metal carboxylate of the carboxylic acid. The reaction of the carboxylic acid with the metal compound is carried out in a continuous manner in an extruder while reaction water being formed is discharged out of the extruder.

Claims

1. A method for producing a stabilizer composition for a polymer, the method comprising: reacting at least one carboxylic acid with at least one metal compound, thereby forming a metal carboxylate of the carboxylic acid, wherein the reaction of the carboxylic acid with the metal compound is carried out in a continuous manner in an extruder while reaction water being formed is discharged out of the extruder.

2. The method according to claim 1, wherein the reaction water is allowed to escape.

3. The method according to claim 1, wherein the discharge of the reaction water takes place through openings of the extruder.

4. The method according to claim 1, wherein the carboxylic acid is fed into the extruder in liquid form.

5. The method according to claim 4, wherein the carboxylic acid is fed into the extruder at a temperature of more than 75° C.

6. The method according to claim 1, wherein a catalyst is supplied for reacting the carboxylic with the metal compound.

7. The method according to claim 6, wherein a weight ratio of carboxylic acid to catalyst is selected in the range from more than 0 to 50.

8. The method according to claim 1, wherein the reaction of the carboxylic acid with the metal compound is carried out in multiple cascaded modules of the extruder.

9. The method according to claim 8, wherein the modules are temperature-controlled in an at least partially separate manner.

10. The method according to claim 8, wherein a temperature of the modules is set such that the carboxylic acid is kept in a liquid state.

11. The method according to claim 8, wherein a temperature of the modules is set to at least 50° C.

12. The method according to claim 1, wherein the reaction of the carboxylic acid with the metal compound is carried out in multiple cascaded modules of the extruder and/or in that additional materials are incorporated into the stabilizer composition in one or more additional modules.

13. The method according to claim 12, wherein the additional modules are temperature-controlled at least partially separately from one another.

14. The method according to claim 9, wherein one or more conveying means in the multiple modules and/or in the additional modules are driven via a single motor.

15. The method according to claim 1, wherein a planetary roller extruder is used.

16. The method according to claim 15, wherein a central spindle of the planetary roller extruder is internally temperature controlled.

17. The method according to claim 1, wherein the stabilizer composition is removed from the extruder as a strand.

18. The method according to claim 1, wherein the stabilizer composition is granulated.

19. A stabilizer composition, obtained according to the method of claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0040] FIG. 1 shows a planetary roller extruder.

DETAILED DESCRIPTION

[0041] Additional features, advantages and effects follow from the exemplary embodiment described below. In the drawing which is thereby referenced, FIG. 1 shows a planetary roller extruder.

[0042] In FIG. 1, an extruder 1 is illustrated which is embodied as a planetary roller extruder. The planetary roller extruder comprises multiple modules 11, 12, 13, 14, 15, 16. The modules 11, 12, 13, 14, 15, 16 are arranged one after another and allow a continuous flow of material in the extruder 1. Each of the modules 11, 12, 13, 14, 15, 16 is connected to a heating/cooling circuit 11a, 12a, 13a, 14a, 15a, 16a. The corresponding circuits are circuits which can be operated with oil or water or another medium. An operation with oil permits a maximum temperature of up to 300° C. and is provided for the modules 11, 12, 13, 14, 15. An operation with water permits a maximum temperature of 220° C. For the module 16, the circuit is operated with water. Although not illustrated, it can also be provided that some of the modules 11, 12, 13, 14, 15, 16 can respectively be operated collectively through one circuit. This is advantageous, for example, for the modules 13, 14 which can be run at approximately the same temperature.

[0043] In addition, as illustrated in FIG. 1, a filling section 10 can be provided into which at least one carboxylic acid, in particular a fatty acid, and at least one metal hydroxide and/or at least one metal oxide and/or at least one metal carbonate and/or at least one basic metal carbonate can be fed and mixed. In principle, however, these components can also be immediately introduced in a metered manner into the first module 11. A dedicated heating/cooling circuit 10a is provided for the filling section 10.

[0044] A central spindle 4 that is driven by a motor 3 passes through the extruder 1. The spindle 4 runs through the filling section 10 and all modules 11, 12, 13, 14, 15, 16 of the extruder. Because the extruder is a planetary roller extruder, the spindle 4 is surrounded by planetary spindles which intermesh with an inner side of each of the modules 11, 12, 13, 14, 15, 16. During operation, it can be ensured by means of a corresponding oblique intermeshing that the material is propelled downstream after being introduced into the extruder 1, so that the material can ultimately exit at a rear end 6 of the extruder 1 opposite from a front end 5 of the extruder 1.

[0045] Downstream, at the modules 11, 12, 13, dispersion discs 7 or other means of distributing mass into a subsequent unit can be provided. A degassing ring 8 can be subsequently arranged downstream at the additional modules 14, 15. The spindle 4 can also be internally temperature-controlled, for which purpose a dedicated circuit 9 is provided which can be operated, for example, with oil up to a temperature of 300° C. In this manner, strong temperature gradients between an outer side of the extruder 1, or expressed more accurately the inner side of the modules 11, 12, 13, 14, 15, 16, and the spindle 4 can be avoided. In other words:

[0046] To a great extent, temperature inhomogeneities in the extruder 1 can be avoided.

[0047] For the supply of material to produce a stabilizer composition, suitable feeds 21, 22, 23, 24, 25, 26, 27, 28 are provided. Furthermore, openings 2 are provided laterally, in particular on the top side as illustrated or in an upper vertical region, on the extruder 1. The openings 2 can be embodied in the form of slots and are laterally surrounded by rising walls 3. Through these slots or openings 2, reaction water forming during a reaction of the previously dispensed carboxylic acids with the metal compounds can escape. It is also possible that this escape of reaction water is actively facilitated, for example by extraction by means of a pump. In principle, however, a corresponding process management can be omitted if the modules 11, 12, 13 are suitably designed. To prevent a foaming, it is also expedient if the reaction water escapes independently or without supporting measures.

[0048] A reaction of the at least one carboxylic acid with the at least one metal hydroxide and/or the at least one metal oxide occurs in the modules 11, 12, 13, which constitute a sort of vessel cascade.

[0049] At the end of the module 13, the reaction water formed will have either completely escaped or at least have been reduced to a desired content. At the end of the module 13, a temperature of the, in this case still liquid, mass can be approximately 200° C. to 250° C. This module 13 can exclusively be provided for the escape of reaction water. The walls 3 can in this case be designed to be higher than those on the module 12. This mass then passes into the module 14 through a final dispersion ring 7. In this module 14, the processed material is still liquid or is present as a melt. Liquid components, premixed powders and/or pigments can then be introduced via the feed 26. Here, a temperature can be approximately 40° C. to 200° C. In the subsequent module 15, additional components, for example zeolites, chalk or co-stabilizers, can once again be admixed via a feed 27. Since the temperature in this region is already significantly lower, the processed mass or the material propelled in the extruder 1 already exhibits a paste-like, much more highly viscous consistency at this position. Finally, in the module 16, which is heated with water, an admixture of thermally sensitive materials occurs via another feed line 28, for example, selected raw materials and/or dyes, at relatively moderate temperatures of 30° C. to 130° C. Like the other feed lines 21, 22, 23, 24, 25, 26, 27, the feed line 28 is equipped with suitable metering means, for example, a scale or a metering pump.

[0050] It can be provided that several of the modules 11, 12, 13, 14, 15, 16 can also be combined into a single module. For example, the modules 11, 12, 13 can be combined into one or two modules. The same applies to the modules 14, 15, 16. The number of modules 11, 12, 13, 14, 15, 16 is at least two, in particular three or more, but has no upper limit.

[0051] Finally, the stabilizer composition produced in such a manner exits the extruder 1 at the end thereof arranged downstream. The strand-shaped material of the stabilizer composition can thereby be removed as such or as a strand. It is also possible that a granulation of the material produced in such a manner is arranged downstream. The temperature in the module 16 is also based thereon. For a removal as a strand, lower temperatures in the range of 30° C. to 80° C. are normally sufficient. If granulation is to take place or tablets are to be produced, the temperature is higher, in the range of approximately 110° C. to 140° C.

[0052] Optionally, safety devices such as screens or magnetic separators can also be affixed to the end of the extruder 1 in order to trap any contamination in the finished stabilizer composition. However, these devices can also be installed at some or all of the feeds 21, 22, 23, 24, 25, 26, 27, 28.

[0053] In Tables 1 and 2 below, typical parameters for producing a stabilizer composition with an extruder 1 of the type described above are illustrated.

TABLE-US-00001 TABLE 1 Composition for stabilizer composition Composition Component [%] Stearic acid, liquid (100° C.) 27.8 Calcium hydroxide Ca(OH).sub.2 3.9 Zinc oxide ZnO 1.3 Catalyst (H.sub.2O) 1.7 Paraffin wax (drop point 55° C. to 77° C.) 5.5 Dilauryl thiodipropionate 4.6 Antioxidant (Irganox 1076) 4.9 Alcamizer P93 (Kisuma) 50.3 Total 100

TABLE-US-00002 TABLE 2 Temperature setting System component Temperature [° C.] Spindle 4 160 Filling section 10 passive* Module 11 180 Module 12 160 Module 13 160 Module 14 120 Module 15  60 Module 16 passive* *passive means that the corresponding heating/cooling circuit is not active

[0054] Not only can a stabilizer composition produced according to Table 1 and 2 be produced in large quantities in little time as strand material or granulate to be cut to length; due to the tailored process conditions and the extrusion via a planetary roller extruder, it also exhibits a high homogeneity and quality with a predefined and reproducible water content.