Method and device for producing stabilizer composition in particulate form and stabilizer composition produced thereby

Abstract

The invention relates to a method for producing a stabilizer composition (38) in the form of granules, in which the stabilizer composition (38) is produced and pressed in a flowable state through at least one opening (34) to form a strand, and then the stabilizer composition (38) exiting the at least one opening (34) is cut to length under the supply of a coolant to form granules (39); a mixture of liquid and gas is supplied as a coolant. Further disclosed is a device (31) for producing such a stabilizer composition (38), as well as a correspondingly produced stabilizer composition (38) in particulate form.

Description

Technical Field

[0001] The present invention relates to a method for producing a stabilizer composition in particulate form, wherein the stabilizer composition is produced and extruded in a flowable state through at least one opening to form a strand, and then the stabilizer composition emerging from the at least one opening is cut to length under the supply of a coolant to form particles.

[0002] The present invention also relates to an apparatus for producing a stabilizer composition in particulate form, comprising: a mixing device for processing components into a flowable stabilizer composition; a granulating unit having at least one opening through which the flowable stabilizer composition supplied by the mixing device can be introduced; and a separating unit by which the stabilizer composition introduced into the granulating unit can be cut to length to form particles; and a coolant supply device for supplying a coolant to the particles.

[0003] The present invention also relates to a stabilizer composition in particulate form. Background Art

[0004] Stabilizers are used in plastics to increase their stability first during processing and then during use, for example in shaped products such as profiles. The corresponding stabilizer compositions usually contain a plurality of components, and the use of these components solves the resistance to various aspects such as light irradiation (especially UV exposure), temperature, atmospheric conditions, etc. The individual components can also be specifically mixed for processing. The individual components are generally mainly organic components on the one hand, such as various fatty acids or their salts, and inorganic materials on the other hand, such as zeolites or titanium dioxide. During the processing of plastics such as polyvinyl chloride (PVC), the stabilizer composition is then mixed therewith, wherein both the plastic and the stabilizer composition are preferably in powder form. For this purpose, it is again preferred to supply the stabilizer composition used to the plastic processor in particulate form.

[0005] In other words, the disadvantage of stabilizers in powder form is that they are prone to dust explosions, while this does not occur with stabilizers in particulate form. Then, during processing, the delivered particles themselves are directly pulverized into powder for safe transportation and equally safe storage ultimately, or for providing safe transportation and equally safe storage until use.

[0006] To produce particles of a stabilizer composition, the stabilizer composition must be extruded through a perforated plate and cut to length. For example, a rotary knife can be used to achieve this. In this context, it is also known to introduce water to remove and at the same time cool the produced and cut-to-length particles. In this context, experts call this underwater granulation.

[0007] As described above, due to the different properties of the individual components and the resulting very different performance thereof, the processing of stabilizer compositions is usually difficult. In particular, the viscosity of the mixture to be processed can cause major problems. For example, if tablets are to be produced instead of granules, this is carried out in a batch process by mixing the components and then dripping them onto a cooling belt, which is only possible with a suitable set viscosity. Otherwise, it is not possible to produce a suitable stabilizer composition in the batch process. Persons skilled in the art have to deal with similar problems during the granulation process. If the stabilizer composition produced has a low viscosity when extruded through a perforated plate, the partial strands or subsequently sized granules formed by extrusion through the perforated plate easily stick together. This is a frequently occurring problem because the extruded stabilizer composition has to be sized at a relatively high temperature in a quasi-pasty state. Therefore, underwater granulation is carried out with water for intensive cooling. This is to prevent the partial strands and / or individual granules from sticking together.

[0008] Although it has been found that underwater granulation can prevent the unwanted adhesion of individual granule particles, it also brings considerable disadvantages: First, the stabilizer material is sized during the granulation process and thus its surface area increases, which is significant because it has previously been separated into partial strands. Because of contact with water, water-soluble components of the stabilizer composition (e.g., co-stabilizers such as calcium acetylacetonate) or inorganic components (e.g., soluble salts such as sodium perchlorate) may dissolve out to such an extent that the intended stabilizer composition can no longer be accurately obtained. In addition, contact with water (a relatively strong cooling medium) leads to the fact that the surface of the granules often becomes covered with cracks. This in turn results in a relatively high proportion of fines in the granules, i.e., the proportion of fines is significant. For those processing plastics, this is undesirable for storage in silos and makes conveying and precise metering more difficult. These disadvantages may be exacerbated if the handling of the granules also causes individual edges of the surface cracks to break off, further increasing the proportion of fines.

[0009] In addition, due to the non-uniform distribution of the granules, the achievable bulk density is also reduced.

[0010] A further disadvantage is that it has been found that underwater granulation with water causes a deviation in the color of the granules. Although these effects have not been fully elucidated, this seems to be due to the close contact with water during the granulation process. Summary of the Invention

[0011] This is where the present invention comes in. An object of the present invention is to further develop a method of the type described at the beginning in such a way that the above-mentioned disadvantages are eliminated or at least reduced.

[0012] A further object of the present invention is to specifically describe a device of the type described at the beginning, by means of which the method according to the present invention can be implemented, thereby achieving corresponding advantages.

[0013] Finally, an object of the present invention is to specifically describe a correspondingly produced stabilizer composition.

[0014] If, in the method of the type described at the beginning, a mixture of liquid and gas is provided as a coolant, the first object of the present invention can be achieved.

[0015] In the context of the present invention, it has been shown that the above-mentioned disadvantages can be avoided or at least reduced in the corresponding method. Particularly advantageously, due to the combined granulation with water and air, especially the combined granulation with a water-air mixture, particles with very few surface cracks and especially a low fines fraction can be produced. This is beneficial for subsequent storage and transportation, because the fines fraction is very low and does not even increase significantly during transportation, because edge breakage is avoided due to fewer surface cracks, and the bulk density of the particles is also improved.

[0016] In particular, the stabilizer composition can also be processed using an extruder (especially a planetary roller extruder) by means of the method according to the present invention. The basic problem with using an extruder or especially a planetary roller extruder is that due to the shear forces introduced during processing, the stabilizer composition reaches a relatively high temperature in the mixed state. Of course, in order to achieve a uniform mixing of the starting components of the stabilizer composition, it is desirable to introduce high shear forces, but this also leads to a high energy input. The effect of the water-air mixture in the granulation process ensures that sufficient energy is dissipated, so that the individual particle particles present after sizing do not adhere to each other. Applying a water-air mixture seems to be beneficial for the particle particles not to adhere or to separate well after sizing. In addition, a certain proportion of air in the water-air mixture also significantly reduces the dissolution of the individual components in the finished particles due to the influence of water, especially for water-soluble components such as sodium perchlorate, etc.

[0017] In principle, within the scope of the present invention, any desired liquid can be used as the liquid. The liquid only needs to provide a transportation and cooling function. For this purpose, water is preferably used because it is an easily accessible and easily handled resource.

[0018] A plurality of gases can also be used, just as essentially different liquids are used. Particularly suitable for this purpose are easily handled inert gases, such as noble gases, such as argon, or, in the case of the stabilizer composition, inert gases such as nitrogen. Similar to the easily accessible resource of preferably using water as the liquid, air is preferably used as the gas.

[0019] The stabilizer composition is typically cut to size at a temperature of about 50 °C to 100 °C. Then, a liquid (such as water) is preferably supplied at a temperature of up to 60 °C, particularly up to 50 °C, for example in the temperature range of 35 °C to 50 °C. Air or an optional further gas is preferably supplied at ambient temperature.

[0020] The liquid and the gas can be mixed in a chamber that can be located before the point of emergence of the stabilizer composition or of the granules produced by the cut-to-size operation. As the stabilizer composition is continuously supplied, for example by continuous extrusion through an extruder (such as a planetary roller extruder), the flow rates of the liquid (such as water) and the gas (such as air) can be adjusted according to the throughput of the stabilizer composition.

[0021] Preferably, an extruder can be used to prepare the stabilizer composition. In particular, a planetary roller extruder can be used. The advantage of a planetary roller extruder is that the stabilizer composition can be prepared in a continuous manner. If a planetary roller extruder with multiple modules is used, the shear force in each module can also be adjusted by the number of planetary rollers used, which is advantageous in order to be able to influence the temperature of the emerging stabilizer composition, particularly at the end of the planetary roller extruder. The introduction of shear force also results in an energy input and thus essentially in a temperature increase. If fewer planetary rollers are provided in the corresponding module at the end of the planetary roller extruder, the introduced shear force and thus the temperature of the stabilizer composition decrease towards the end of the extruder, which in turn provides an optimal granulation temperature for the stabilizer composition. The temperature is determined in such a way that the flowable and thus forward-pushing stabilizer composition can still move well, but on the other hand, the temperature is not so high that the stabilizer composition has a very high fluidity and, despite the supply of a mixture of liquid and gas, the cut-to-size granules still stick together and only form sticky aggregates with a shape that cannot be strictly defined. A temperature range of about 55 °C to 100 °C for the above-mentioned extruded stabilizer composition has proven to be a suitable temperature range for granulation.

[0022] In particular, a planetary roller extruder having multiple modules (preferably at least three modules, especially four to eight modules) can be used. The advantage of a planetary roller extruder with multiple modules is that the temperature of each module can be controlled individually, so that the required temperature or temperature range can be set along the extruder according to each reaction or mixing process and, if appropriate, the release of water. In this case, the shear force can also be changed, so that the shear force can be adjusted in each module. Here, the number of modules is preferably maintained to be suitable for the stabilizer composition to be produced or the components required for this purpose. Basically, the temperature range of the extruded components is about 80 °C to 240 °C. For this purpose, the temperature is preferably set to rise first along the planetary roller extruder and then decrease downstream. At the beginning of the planetary roller extruder or the extrusion process, a higher temperature is required to partially melt the components to ensure uniform mixing. At the end of the extrusion process, for example, when mixing the premix and / or temperature-sensitive pigments, the temperature is preferably adjusted to decrease again. In this lower region, sensitive components such as impact modifiers can be mixed so that these components are also only slightly temperature-loaded.

[0023] It is further basically preferred that the shear force in the planetary roller extruder is set to decrease downstream, especially by reducing the number of planetary rollers in the downstream direction in the planetary roller extruder. This can be achieved in a simple manner, for example, by providing a smaller number of planetary shafts in the last module of the planetary roller extruder than in the previous modules.

[0024] If there are multiple modules in the planetary roller extruder, the typical temperature range can be selected according to Table 1 below.

[0025] Table 1 : During the process of processing the stabilizer composition in the planetary roller extruder, the temperature range of each module

[0026] Module Number Temperature Range [°C] Preferred Temperature Range [°C] 1 90 to 120 105 to 115 2 180 to 205 185 to 200 3 220 to 250 225 to 245 4 190 to 220 190 to 210 5 160 to 195 170 to 190 6 80 to 115 90 to 110 7 80 to 110 90 to 105

[0027] Preferably, the stabilizer composition is extruded through a plate having multiple openings for granulation. This can be a perforated plate having multiple openings arranged in a circle and preferably equidistant from each other on the circumference of the circle. To bring the extruded strands into the openings and separate them, the plate can have a central tapered widening portion against which the strands impinge during the extrusion process and through which the strands are divided into individual partial strands for the openings.

[0028] When using an extruder, the stabilizer composition usually leaves the extruder without pressure. Therefore, it may be necessary to mechanically convey the stabilizer composition onto the plate. For example, a pump can be provided for the conveying purpose.

[0029] The particles are preferably conveyed from the mixture to a separating device, where the particles are separated from the mixture, and are then optionally dried. Once the particles are sufficiently dry, they can be separated from the mixture again, and the mixture is no longer required in terms of its cooling and transport functions. When doing so, it is preferred to recover the liquid from the mixture and convey it into the circuit for granulation. The supplied gas (usually air) leaves the process, while the liquid (such as water) is recycled.

[0030] In a device of the type described at the beginning, a coolant supply device having at least one first inlet for a liquid and at least one second inlet for a gas is provided to supply a mixture of liquid and gas as a coolant, which achieves another object of the present invention.

[0031] The corresponding device is particularly suitable for implementing the method according to the present invention. Advantageously, the device enables the production of granules with highly uniform granule particles. Generally, the granule particles have a surface with fewer cracks and thus a surface that is more suitable for storage and processing. A surface with fewer cracks results in a lower fines fraction, which is advantageous during conveying, storage, and subsequent processing or handling.

[0032] The mixing device is preferably an extruder, particularly a planetary roller extruder. As described above, when using a planetary roller extruder in particular, the temperature during the discharging process can be targeted controlled or adjusted, so that the best quality of the surface of the granule particles can be obtained.

[0033] The coolant supply device can be particularly connected to a water reservoir. This enables the mixing of water for granulation with a gas (such as air), and after passing through a circulation process, it is recycled for further granulation.

[0034] The device according to the present invention can have a conveying line and a separating device. The particles can be conveyed along the conveying line by a coolant, and the separating device is used to separate the particles from the coolant. The conveying line connects the granulation unit and the separating device. It is advantageous here to provide a circuit through which the coolant can be guided.

[0035] On the other hand, the present invention relates to a stabilizer composition in the form of granules prepared according to the present invention. The greatest feature of the granules is that, compared with granules granulated only with water, they basically have a more uniform and less cracked surface. This has advantages in terms of transportation, storage, and processing. In addition, the color deviation of the granules is smaller, and the so-called multiple grains, that is, the accumulation of multiple interconnected granule particles, are also avoided.

[0036] In principle, any desired stabilizer composition can be processed within the scope of the present invention.

[0037] The stabilizer composition is preferably formed without heavy metals, except for small amounts of zinc or zinc salts. In one variant, the stabilizer composition processed according to the invention does not contain lead, except for possible production-related impurities.

[0038] In particular, the stabilizer composition may comprise the components described below, and advantageously these components are mixed or partially reacted during the production process, even before adding any impact modifier. Unless otherwise stated, the percentage (%) data refers to weight percentage.

[0039] Except for small amounts of zinc, the stabilizer composition processed according to the invention does not contain heavy metals, and this stabilizer composition can generally coexist with one or more additives, such as primary stabilizers, co-stabilizers, zeolites, antioxidants, fillers, plasticizers, dyes, pigments, antistatic agents, surfactants, blowing agents, (other) impact modifiers, UV stabilizers, lubricants, processing aids and / or the like.

[0040] Examples of stabilizers are generally epoxides and epoxidized fatty acid esters, phosphites, thiophosphites and thiophosphates, polyols, 1,3-dicarbonyl compounds, mercapto carboxylates, dihydropyridines, antioxidants, light stabilizers and UV absorbers, alkali metal and alkaline earth metal compounds, perchlorates, zeolites, hydrotalcites or dawsonites.

[0041] Further common additives (especially additives for PVC), unless already included, are for example lubricants, plasticizers, other impact modifiers, processing aids, foaming agents, fillers, antistatic agents, biocides, antifogging agents, pigments and dyes, metal deactivators and flame retardants (in this regard, see "Handbook of PVC Formulating" by E.J. Wickson, John Wiley & Sons, New York 1993), and can likewise be mixed with the stabilizer composition.

[0042] Examples of components for use as or as stabilizers or additives are known to those skilled in the art (R.-D. Maier, M. Schiller, Handbuch Kunststoff-Additive, 4th edition, Hanser Verlag, 2016). Some lists of such components are given below only by way of example.

[0043] In particular, suitable phosphites are co-stabilizers for chlorine-containing polymers, such as trioctyl-, tridecyl-, tridodecyl-, tritridecyl-, tripentadecyl-, trioctadecenyl-, tristearyl-, triphenyl-, tritolyl-, trinonylphenyl-, tri-2,4-tert-butylphenyl- or tricyclohexyl phosphite.

[0044] A variety of further phosphites can also be used, such as various mixed aryldialkyl phosphites or alkyldiaryl phosphites, such as phenyldioctyl-, phenyldidecyl-, phenyldidodecyl-, phenylditridecyl-, phenylditetradecyl-, phenyldipentadecyl-, octyldiphenyl-, decyldiphenyl-, undecyldiphenyl-, dodecyldiphenyl-, tridecyldiphenyl-, tetradecyldiphenyl-, pentadecyldiphenyl-, octadecenyl diphenyl-, stearyl diphenyl- and dodecyl-2,4-di-tert-butylphenyl phosphite.

[0045] In addition, phosphites of various diols or polyols can also be advantageously used, such as tetraphenyldipropylene glycol diphosphite, polydipropylene glycol phenyl phosphite, tetrakis(hydroxymethyl)cyclohexanol-decyl diphosphite, tetrakis(hydroxymethyl)cyclohexanol-butoxyethoxy-ethyl diphosphite, tetrakis(hydroxymethyl)cyclohexanol-nonylphenyl diphosphite, bis-nonylphenyl-di-trimethylolpropane diphosphite, bis-2-butoxyethyl-di-trimethylolpropane diphosphite, trihydroxyethyl isocyanurate-hexadecyl triphosphite, didecyl pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis-2,4-di-tert-butylphenyl pentaerythritol diphosphite. Mixtures of these phosphites and aryl / alkyl phosphite mixtures can also be used in the stabilizer compositions according to the invention.

[0046] Based on 100 parts by weight of the polymer (such as PVC), the amount of the organic phosphite can be, for example, from 0.01 to 10 parts by weight, suitably from 0.05 to 5 parts by weight, and in particular from 0.1 to 3 parts by weight.

[0047] For example, the following polyols can be used: pentaerythritol, dipentaerythritol, tripentaerythritol, ditrimethylolpropane, trimethylolethane, ditrimethylolethane, trimethylolpropane, sorbitol, maltitol, isomaltitol, lactitol, lycasin, mannitol, lactose, leucrose, tris(2-hydroxyethyl) isocyanurate, tetramethylolcyclohexanol (TMCH), tetramethylolcyclopentanol, tetramethylolcyclopyranol, glycerol, diglycerol, polyglycerol, thiodiglycerol, 1-O-α-D-glucopyranosyl-D-mannitol dihydrate, and polyvinyl alcohol and cyclodextrin. Among them, TMCH and diols are preferred. Based on 100 parts by weight of the polymer (such as PVC), the amount of the polyol can be, for example, 0.01 to 20 parts by weight, advantageously 0.1 to 20 parts by weight, particularly 0.1 to 10 parts by weight.

[0048] The thionophosphite or thiophosphate is of the general type (RS) 3 P, (RS) 3 P=O or (RS) 3 P=S compounds. Exemplary compounds are tris(hexylthio)phosphite, tris(octylthio)phosphite, tris(dodecylthio)phosphite, tris(benzylthio)phosphite, tris-[carboxy-isooctyloxy]-methyl trithiophosphate, tris-[carbonyl-isooctyloxy]-methyl trithiophosphate, tris-[carbonyl-2-ethylhexyloxy]-methyl trithiophosphate, tris-1-[carbonyl-hexyloxy]-ethyl trithiophosphate, tris-1-[carbonyl-2-ethylhexyloxy]-ethyl trithiophosphate, tris-2-[carbonyl-2-ethylhexyloxy]-ethyl trithiophosphate. Advantageously, the thionophosphite or thiophosphate can be present in the chlorine-containing polymer (such as PVC) in an amount of 0.01% to 20%, preferably 0.1% to 5%, particularly 0.1% to 1%.

[0049] Examples of 1,3-dicarbonyl compounds are acetylacetone, butyrylacetone, heptanoylacetone, stearoylacetone, palmitoylacetone, lauroylacetone, 7-tert-nonylthioheptanedione-2,4, benzoylacetone, dibenzoylmethane, lauroylbenzoylmethane, palmitoylbenzoylmethane, stearoylbenzoylmethane, isooctylbenzoylmethane, 5-hydroxyhexanoylbenzoylmethane, tribenzoylmethane, bis(4-methylbenzoyl)methane, benzoyl-p-chlorobenzoylmethane, bis(2-hydroxybenzoyl)methane, 4-methoxybenzoyl-benzoylmethane, bis(4-methoxybenzoyl)methane, 1-benzoyl-1-acetylnonane, benzoyl-acetyl-phenylmethane, stearoyl-4-methoxy-benzoylmethane, bis(4-tert-butylbenzoyl)methane, benzoyl-formylmethane, benzoyl-phenylacetylmethane, bis(cyclohexanoyl)methane, bis(pivaloyl)methane, methyl, ethyl, hexyl, octyl, dodecyl or octadecyl acetoacetate, ethyl, butyl, 2-ethylhexyl, dodecyl or octadecyl benzoylacetate, ethyl, propyl, butyl, hexyl or octyl stearoylacetate and dehydroacetic acid and their zinc, alkali metal, alkaline earth metal and / or aluminium salts. Based on 100 parts by weight of the polymer (e.g. PVC), the amount of 1,3-dicarbonyl compound can be, for example, from 0.01 to 10 parts by weight, advantageously from 0.01 to 3 parts by weight, in particular from 0.01 to 2 parts by weight.

[0050] Examples which may be mentioned of mercapto-carboxylic esters are mercaptoacetates, thiomalates, mercaptopropionates, mercaptobenzoates or thiolactates, as described, for example, in EP 0 365 483 A1. Mercapto-carboxylic esters also include the corresponding polyol esters or their partial esters. Advantageously, the corresponding esters can be present in the chlorine-containing polymer in an amount of from 0.01% to 10%, preferably from 0.1% to 5%, in particular from 0.1% to 1%.

[0051] The stabilizer composition according to the invention can additionally comprise at least one epoxidized fatty acid ester. Preferably esters of fatty acids from natural sources (such as soybean oil or rapeseed oil). Based on 100 parts by weight of the composition, the amount of epoxide is, for example, 0.1 part by weight, advantageously from 0.1 to 30 parts by weight, in particular from 0.5 to 25 parts by weight. Other examples are epoxidized polybutadiene, epoxidized linseed oil, epoxidized fish oil, epoxidized tallow, methyl butyl- or 2-ethylhexyl epoxystearate, tris(epoxypropyl)isocyanurate, epoxidized castor oil, epoxidized sunflower oil, 3-phenoxy-1,2-epoxypropane, bisphenol A diglycidyl ether, vinylcyclohexene diepoxide and / or dicyclopentadiene diepoxide. Bisphenol A and bisphenol F derivatives can also be regarded as epoxides.

[0052] Furthermore, monomeric dihydropyridines and / or polydihydropyridines as disclosed in EP 0 796 888 A2 can be provided as stabilizers. Advantageously, based on 100 parts by weight of the polymer, the amount of (poly-)dihydropyridine in the chlorine-containing polymer can be from 0.001 to 5 parts by weight, in particular from 0.005 to 1 part by weight. Furthermore, as disclosed in EP 0 796 888 A2, sterically hindered amines can be provided as stabilizers.

[0053] The stabilizer composition according to the invention can contain alkali metal and alkaline earth metal compounds, in particular carboxylates of the above acids, and can also contain the corresponding oxides or hydroxides, carbonates or basic carbonates. Mixtures thereof with organic acids can also be considered. Examples are NaOH, KOH, CaO, Ca(OH) 2 , MgO, Mg(OH) 2 , CaCO 3 , MgCO 3 , dolomite, zinc oxide, zinc carbonate and fatty acid Na, K, Ca, Mg or Zn salts. In the case of alkaline earth metal and Zn carboxylates, adducts thereof with MO or M(OH) 2 (M = Ca, Mg, Sr or Zn), so-called "overbased" compounds, can also be used. Preferably, alkali metal carboxylates, alkaline earth metal carboxylates and / or aluminum carboxylates, such as sodium stearate, potassium stearate, calcium stearate or aluminum stearate, are additionally used in the stabilizer according to the invention.

[0054] The stabilizer composition can contain, for example, one or more perchlorates, such as perchlorates of the general formula M(ClO 4 )n, where M represents Li, Na, K, Mg, Ca, Ba, Zn, Al, Ce or La. The exponent n varies from 1 to 3 according to the valence of M and is thus 1, 2 or 3. The perchlorates can be complexed with alcohols or ether alcohols. Here, specific perchlorates can be used in various common forms, for example as salts applied to carrier materials (such as PVC, calcium silicate, zeolite or hydrotalcite) or aqueous solutions, or can be obtained by chemical reaction of hydrotalcite with perchloric acid. Alternatively or additionally, perchlorate-intercalated layered silicates, such as hydrotalcite, can also be used. An exemplary compound of this group is the product of Kisuma Chemicals. For example, based on 100 parts by weight of PVC or other polymer, the amount of perchlorate can be from 0.001 to 5 parts by weight, advantageously from 0.01 to 3 parts by weight, and particularly preferably from 0.01 to 2 parts by weight.

[0055] A co-stabilizer is a compound that can provide a further stabilizing contribution to a halogen-containing polymer. Possible co-stabilizers may be selected from the group consisting of: 1,3-diketone compounds, polyols, metal salts, natural or synthetic minerals (such as hydrotalcite, hydrocalumite and zeolites), amino acid derivatives, organic esters of phosphorous acid and epoxides.

[0056] Examples of 1,3-diketone compounds include but are not limited to dibenzoylmethane, stearoylbenzoylmethane, palmitoylbenzoylmethane, myristoylbenzoylmethane, lauroylbenzoylmethane, benzoylacetone, acetylacetone, tribenzoylmethane, diacetylacetophenone, p-methoxystearoylacetophenone, acetoacetates and acetylacetone and their metal salts, in particular salts of lithium, sodium, potassium, calcium, magnesium, titanium and / or aluminium.

[0057] Co-stabilizers from the polyol group include, but are not limited to, glycerol, pentaerythritol, dipentaerythritol and tripentaerythritol, trimethylolpropane (TMP), di-TMP, sorbitol, mannitol, maltitol, sugars, disaccharides (especially sucrose, 4-O-β-D-galactopyranosyl-D-glucose, 4-O-α-D-glucopyranosyl-D-glucose, 6-O-(6-deoxy-α-L-mannopyranosyl)-D-glucose, α-D-glucopyranosyl-α-D-glucopyranoside, 6-O-α-D-glucopyranosyl-D-glucose, 4-O-β-D-glucopyranosyl-D-glucose, 2-O-β-D-glucopyranosyl-D-glucose, 6-O-α-D-glucopyranosyl-D-sorbitol, 3-O-α-D-glucopyranosyl-D-fructose, 6-O-β-D-glucopyranosyl-D-glucose, 4-O-β-D-galactopyranosyl-D-sorbitol, 4-O-α-D-glucopyranosyl-D-sorbitol, 6-O-α-D-galactopyranosyl-D-glucose, 3-O-α-D-galactopyranosyl-D-myo-inositol, 4-O-β-D-galactopyranosyl-D-fructose, 4-O-β-D-galactopyranosyl-β-D-glucopyranose, β-O-α-D-glucopyranosyl-D-fructose, 4-O-β-D-galactopyranosyl-α-D-glucopyranose, 2-O-(6-deoxy-α-L-mannopyranosyl)-D-glucose, 4-O-α-D-glucopyranosyl-D-fructose, 2-O-β-D-glucopyranosyl-α-D-glucopyranose, 1-O-α-D-glucopyranosyl-D-mannitol, 6-O-(6-deoxy-α-L-mannopyranosyl)-β-D-glucopyranose, 2-O-β-D-glucopyranosyl-β-D-glucopyranose, 6-O-α-D-glucopyranosyl-α-D-glucopyranose, 2-O-α-D-glucopyranosyl-α-D-glucopyranose, 2-O-α-D-glucopyranosyl-β-D-glucopyranose, 1-O-α-D-glucopyranosyl-D-fructose, 6-O-α-D-glucopyranosyl-α-D-fructofuranose, 6-O-α-D-glucopyranosyl-D-sorbitol, 4-O-β-D-galactopyranosyl-D-sorbitol, 4-O-α-D-glucopyranosyl-D-sorbitol, 1-O-α-D-glucopyranosyl-D-mannitol, trisaccharides, polysaccharides, especially polyvinyl alcohol, starch, cellulose and their partial esters.

[0058] Examples of antioxidants include, but are not limited to, alkylphenols, hydroxyphenyl propionates, hydroxybenzyl compounds, alkylidene bisphenols, thio-bisphenols, and aminophenols, especially, for example, 2,6-di-tert-butyl-4-methylphenol, 2,6-dibenzyl-4-methylphenol, stearyl 3-(3’,5’-di-tert-butyl-4’-hydroxyphenyl) propionate, 4,4’-thio-bis(3-methyl-6-tert-butylphenol), 4-nonylphenol, 2,2’-methylenebis(4-methyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, 4,4’,4”-(1-methyl-1-propylidene-3-ylidene) tris[2-(1,1-dimethylethyl)-5-methylphenol], their neutral or basic lithium, magnesium, calcium, and aluminum salts, and sterically hindered amines and / or phosphites and mixtures thereof.

[0059] Examples of co-stabilizers from the group of metal salts include, but are not limited to, hydroxides, oxides, carbonates, basic carbonates, and carboxylates of lithium, sodium, potassium, magnesium, calcium, aluminum, titanium, etc., provided that heavy metals (except zinc) are not used. In one embodiment of the present invention, the metal salt may be a salt of a higher carboxylic acid, and the higher carboxylic acid is, for example, C 6 -C 22 carboxylic acids, such as stearic acid, palmitic acid, myristic acid, lauric acid, oleic acid, and ricinoleic acid.

[0060] Examples of natural and synthetic minerals include, but are not limited to, A3 zeolite, A4 zeolite, A5 zeolite, mordenite, erionite, faujasite type X or Y, and ZSM-5 zeolite, hydrotalcite ( types 1 and 4) and / or mixtures thereof.

[0061] Mesoporous materials, especially mesoporous silicates, such as MCM-41 or SBA-15, can also be components of the stabilizer composition according to the present invention.

[0062] Examples of co-stabilizers from the group of amino acid derivatives include, but are not limited to, glycine, alanine, lysine, tryptophan, acetylmethionine, pyrrolidonecarboxylic acid, α-aminocrotonic acid, α-aminoacrylic acid, α-aminoadipic acid, etc., and their corresponding esters. The alcohol component of these esters may include monohydric alcohols, such as methanol, ethanol, propanol, isopropanol, butanol, α-ethylhexanol, octanol, isooctanol, lauryl alcohol, stearyl alcohol, etc., and polyhydric alcohols, such as ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, glycerol, diglycerol, trimethylolpropane, pentaerythritol, dipentaerythritol, erythritol, sorbitol, mannitol, etc.

[0063] Examples of co-stabilizers from the group of phosphites include, but are not limited to, triaryl phosphites such as triphenyl phosphite, tris(p-nonylphenyl) phosphite; alkylaryl phosphites such as monoalkyl diphenyl phosphites such as diphenyl isooctyl phosphite, diphenyl isodecyl phosphite; and dialkyl monophenyl phosphites such as phenyl diisooctyl phosphite or phenyl diisodecyl phosphite; and trialkyl phosphites such as triisooctyl phosphite, tristearyl phosphite, etc.

[0064] Another component that can be added to the stabilizer composition within the scope of the present invention is titanium dioxide. Titanium dioxide exists mainly in three forms in nature: anatase, brookite, and rutile. Anatase and rutile both have industrial significance as pigments. The high refractive indices of 2.55 (anatase) and 2.75 (rutile) demonstrate their brightening and covering capabilities and can thus be used as white pigments. With an appropriate dosage, rutile completely absorbs light below 400 nm, i.e., the entire UV range. The absorption of anatase is slightly shifted towards shorter wavelengths. In contrast, brookite does not exhibit any photocatalytic activity and is thus not preferred as another component of the stabilizer composition but can be added as a filler.

[0065] Advantageously, titanium dioxide has a rutile structure for outdoor applications. For all other applications, it can have both anatase and rutile structures simultaneously. Combinations of these modifications are also possible.

[0066] In the stabilizer composition, the amount of titanium dioxide can be from about 0.01% to about 20%. In another embodiment, the amount of titanium dioxide can be from about 0.05% to about 10.0%, or from about 0.1% to about 5%, such as about 4%. Titanium dioxide should be present in a finely divided and well-dispersed form.

[0067] For example, paraffin wax can be used as a lubricant. In one embodiment, the paraffin wax can be a mixture of alkanes having the general empirical formula C n H 2n+2 where n is an integer from 20 to 100. The mixture can consist of straight-chain and odd-chain components or can consist of pure straight-chain components. Examples of commercially available and usable paraffin waxes include, but are not limited to, Fischer-Tropsch paraffin wax and related compounds.

[0068] Fillers can be provided as components of the stabilizer composition but are not necessarily components thereof.

[0069] The further co-stabilizers indicated above can be used in the same amount as the lubricant.

[0070] Further features, advantages, and effects of the present invention result from the exemplary embodiments shown below. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In the accompanying drawings referred to in this text:

[0072] Figure 1 A planetary roller extruder is shown;

[0073] Figure 2 A schematic diagram of a granulation unit is shown;

[0074] Figure 3 A photograph of the produced granules is shown. Detailed implementation manners

[0075] Figure 1 An extruder for processing or producing a stabilizer composition is shown. The extruder is a planetary roller extruder 1.

[0076] The planetary roller extruder has a first end 2 and a second end 3 opposite to the first end 2. The planetary roller extruder 1 is composed of a plurality of modules 10, 11, 12, 13, 14, 15, 16. Each of these modules 10, 11, 12, 13, 14, 15, 16 is respectively equipped with a circuit 10a, 11a, 12a, 13a, 14a, 15a, 16a having a heating and / or cooling function. A fluid (especially oil) can circulate in these circuits 10a, 11a, 12a, 13a, 14a, 15a, 16a to bring each module 10, 11, 12, 13, 14, 15, 16 to the required temperature or maintain it at this temperature during the processing of the composition. If necessary, a temperature change can also be carried out. A similar circuit p is provided to control the temperature of the shaft 4.

[0077] The shaft 4 of the planetary roller extruder 1 passes through the modules 10, 11, 12, 13, 14, 15, 16. The shaft 4 is a central driving element. On the outside, the shaft 4 is surrounded by a plurality of invisible planetary shafts (not shown), as is customary for a planetary roller extruder 1. The number of planetary shafts arranged around the shaft 4 in the modules 10, 11, 12, 13, 14, 15, 16 can vary for each module 10, 11, 12, 13, 14, 15, 16. Generally, three, five or seven planetary shafts are provided in each module 10, 11, 12, 13, 14, 15, 16. In addition, the planetary roller extruder 1 can include a dispersion disk 8 located between the respective modules 10, 11, 12, 13, 14, 15, 16 and a degassing disk 9 located downstream thereof.

[0078] The shaft 4 is connected to an electric motor (not shown) and the shaft 4 can be set in rotational motion. By doing so, the shaft 4 runs at a freely selectable rotational speed, for example, the rotational speed is generally 200 rpm to 400 rpm, the inner diameter of the extruder is 100 mm to 120 mm and the central shaft diameter is 70 mm to 75 mm. It has been proven that rotational speeds in the range of about 275 rpm to 375 rpm are particularly useful for the exemplary extruder dimensions. The shear force in the modules 10, 11, 12, 13, 14, 15, 16 can be set by the rotational speed and the number of planetary shafts arranged around the shaft 4, which allows the production of stabilizer compositions that otherwise cannot be produced or can only be produced with unsatisfactory results, as will still be explained below.

[0079] According to Figure 1 the planetary roller extruder 1 also has a plurality of outlets 5, 6, 7. The outlets 5, 6, 7 are not necessarily provided, but are advantageous and beneficial when processing stabilizer compositions that tend to form a large amount of foam during processing. For example, this is the case when processing stabilizer compositions containing fatty acids or their derivatives, in which water is released during their reaction. The cross-section of the outlets 5, 6, 7 arranged on the upper side of the housing of the respective modules 10, 11, 12, 13, 14, 15, 16 of the planetary roller extruder 1 is preferably formed in a rectangular shape. In particular, they can be outlets 5, 6, 7 extending upward in the form of a rectangular cuboid or a slit, so that controlled foaming can occur with the release of water without the stabilizer composition to be processed leaking out therefrom. On the contrary, when the stabilizer composition to be processed is driven forward in the direction of the second end 3 by the cooperation of the shaft 4 and the corresponding planetary shafts downstream, only water leakage will occur.

[0080] The planetary roller extruder 1 must be loaded in a suitable manner to produce the stabilizer composition. For this purpose, separate feeding devices or feeders 21, 22, 23, 24, 25, 26 can be provided. The feeding of the respective components for preparing the stabilizer composition is carried out in the corresponding feeders 21, 22, 23, 24, 25, 26, where the feeding can be adjusted according to the temperature, shear force and uniformity of the stabilizer components of the modules 10, 11, 12, 13, 14, 15, 16.

[0081] When producing the stabilizer composition, the temperatures of the respective modules 10, 11, 12, 13, 14, 15, 16 are controlled respectively by the circuits 10a, 11a, 12a, 13a, 14a, 15a, 16a. Table 2 below lists the typical temperatures of the respective modules in the production of the stabilizer composition, and an impact modifier is used to produce this stabilizer composition. The temperature of the melt pump refers to the temperature of the pump arranged downstream of the extruder for pressurizing the discharged stabilizer composition.

[0082] Table 2: Circuit temperatures of each module

[0083] Module Melt Pump p 10 11 12 13 14 15 16 Circuit Temperature [°C] 100 110 190 240 200 180 120 120 90

[0084] Figure 2 Schematically shows a device 31 according to the present invention. The device 3 includes a mixing device 32, which can be the planetary roller extruder 1 explained in more detail above, but this is not mandatory. In principle, another extruder can also be used. However, as explained, the planetary roller extruder 1 is preferred. The extruded stabilizer composition 38 is discharged from the mixing device 32 without pressure and is driven forward in the form of a strand by a pump or, as shown, by rollers 42 to the granulation unit 33, and the strand enters the granulation unit 33 through an opening 34. For this purpose, the strand or the stabilizer composition 38 is divided into partial strands by a perforated plate, as Figure 2 shown schematically. For this purpose, the perforated plate can be designed conically so that the strand impinges on the cone, thereby guiding the partial strands to the opening 34.

[0085] A separation unit 40 is provided in the granulation unit 33, and the stabilizer composition supplied in the form of a strand is deflected by means of the separation unit 40. In particular, the separation unit 40 can be one or more rotary knives. The granulation unit 33 has a further opening for discharging the deflected particles 39. As Figure 2 shown, this further opening can be located on the head side so that the deflected particles 39 are discharged against gravity. For this purpose and for cooling purposes, a coolant supply device 35 is provided, through which coolant can be supplied to the granulation unit 33. The deflected particles 39 can be discharged upward against gravity by the supplied coolant. The advantage of this is that the particles 39 do not fall down and stick together, but are carried upward with a high cooling intensity and are cooled in a relatively short time. According to the present invention, as long as the coolant supply device 35 has a first inlet 36 for a liquid (such as water) and a second inlet 37 for a gas (such as air). Therefore, a water-air mixture can be produced, which has a distinct advantage over known particles in terms of particle quality, because the produced particles 39 are very uniform and in particular have a surface that is not very cracked. In addition, multiple grains are avoided, and after being conveyed out along the conveyor line 41, better drying behavior is also noted.

[0086] By Figure 3 comparing the stabilizer composition 38 in Figure 3 it can be seen the advantages achieved. The stabilizer composition 38 conventionally granulated only with water can have an appearance as shown in the left photo in Figure 3The particles 39 shown in the right photograph. This type of particle 39 has significantly better transport and storage properties because the fines fraction is significantly lower, or a significantly lower fines fraction occurs during subsequent storage and during further transport or processing. In addition, a higher color fastness is provided.

[0087] In a typical extrusion process, the temperature of the stabilizer composition 38 when it exits the extruder (e.g., the planetary roller extruder 1) is about 55 °C to 100 °C. For example, water can be supplied at a temperature of 35 °C to 50 °C. The supplied air is at room temperature. The flow rates of water and air can be adjusted according to the throughput of the stabilizer composition 38. At a throughput of the stabilizer composition 38 of about 100 kg / h to 120 kg / h, it is recommended that the flow rate of liquid water be 1 m 3 / h to 3.5 m 3 / h, and the flow rate of air be about 86 Nm 3 / h to 110 Nm 3 / h.

[0088] The number of holes in the perforated plate can also be optimized to achieve optimal granulation conditions. Generally, a perforated plate with five holes and a hole diameter of about 4.5 mm can be provided. When the strands of the stabilizer composition 38 are granulated or extruded through, the temperature of the perforated plate is in the range of about 80 °C to 120 °C. The separation device can be equipped with a rotary knife that rotates, for example, at 650 rpm to 1300 rpm.

[0089] The device 31 can be equipped with Figure 2 a circuit not shown in the figure. The particles 39 are discharged through the conveyor line 41. For example, a water separator or another separation device can be provided on the conveyor line 41 to separate the produced particles 39 from the water. Then the water is recovered and can be used again as a coolant. The particles 39 separated from the water are then further conveyed by a vibrating conveyor and are further dried by air from below during this process.

Claims

1. A method for producing a stabilizer composition (38) in particulate form, wherein, the stabilizer composition (38) is produced and extruded through at least one opening (34) in a flowable state to form a strand, and then the stabilizer composition (38) emerging from the at least one opening (34) is cut to a fixed length under the supply of a coolant to form particles (39), characterized in that a mixture of liquid and gas is supplied as the coolant.

2. The method according to claim 1, characterized in that, water is used as the liquid.

3. The method according to claim 1 or 2, characterized in that, air is used as the gas.

4. The method according to any one of claims 1 to 3, characterized in that, the particles (39) are conveyed by the mixture.

5. The method according to any one of claims 1 to 4, characterized in that, the stabilizer composition (38) is produced by an extruder.

6. The method according to any one of claims 1 to 5, characterized in that, the stabilizer composition (38) is produced by a planetary roller extruder (1).

7. The method according to any one of claims 1 to 6, characterized in that, the stabilizer composition (38) is extruded through a plate having a plurality of openings (34).

8. The method according to claim 7, characterized in that, the stabilizer composition (38) is conveyed to the plate by a pump.

9. The method according to any one of claims 1 to 8, characterized in that, the particles (39) are conveyed by the mixture to a separation device, and then the particles (39) are separated from the mixture in the separation device, and subsequently the particles (39) are optionally dried.

10. An apparatus (31) for producing a stabilizer composition (38) in particulate form, comprising: a mixing device (32) for processing components into a flowable stabilizer composition (38); a granulating unit (33) having at least one opening (34) through which the flowable stabilizer composition (38) supplied by the mixing device (32) can be introduced; and a separation unit (40) by which the stabilizer composition (38) introduced into the granulating unit (33) can be cut to a fixed length to form particles (39); and a coolant supply device (35) for applying a coolant to the particles (39), characterized in that the coolant supply device (35) is formed with at least one first inlet (36) for liquid and at least one second inlet (37) for gas to supply a mixture of liquid and gas as the coolant.

11. The apparatus (31) according to claim 10, characterized in that, the mixing device (32) is an extruder, particularly a planetary roller extruder.

12. The apparatus (31) according to claim 10 or 11, characterized in that, the coolant supply device (35) is in communication with a reservoir.

13. The device (31) according to any one of claims 10 to 12, characterized in that, a conveyor line (41) and a separation device are provided, the particles can be conveyed by the coolant along the conveyor line (41), and the separation device is used to separate the particles (39) from the coolant, wherein the conveyor line (41) connects the granulation unit (33) and the separation device together.

14. The device (31) according to any one of claims 10 to 13, characterized in that, a circuit capable of guiding the coolant is provided.

15. A stabilizer composition (38) in the form of particles obtainable according to any one of claims 1 to 10.

Images