EP4308363A1

EP4308363A1 - Method for producing a stabiliser composition for a polymer, and stabiliser composition produced using said method

Info

Publication number: EP4308363A1
Application number: EP22701286.1A
Authority: EP
Inventors: Georg Andreas MEINHARDT; Karl SCHULLER; Michael Hecher
Original assignee: Akdeniz Chemson Additives Ag
Current assignee: Akdeniz Chemson Additives Ag
Priority date: 2021-03-19
Filing date: 2022-01-24
Publication date: 2024-01-24
Also published as: US20240165866A1; AT524902A1; BR112023018416A2; CN117320866A; WO2022192928A1; AU2022236929A1

Abstract

The invention relates to a method for producing a stabiliser composition for a polymer, particularly a polymer containing halogen such as polyvinyl chloride, in which components for forming the stabiliser composition are mixed in an extruder and continuously discharged therefrom. According to the invention, an impact modifier is admixed. The invention also discloses a correspondingly produced stabiliser composition and the use of a planetary roller extruder (1) to produce a stabiliser composition.

Description

Method of making a stabilizer composition for a polymer and stabilizer composition made therewith

The invention relates to a process for producing a stabilizer composition for a polymer, in particular a halogen-containing polymer such as polyvinyl chloride, with components for forming the stabilizer composition being mixed in an extruder and continuously discharged from the extruder.

Furthermore, the invention relates to a stabilizer composition.

Finally, the invention relates to the use of a planetary roller extruder.

Many polymeric plastics or polymers such as polyvinyl chloride (PVC) have a diverse range of properties and can tend to thermal decomposition both during or during production and during further processing, for example by extrusion, calendering or injection molding. In addition, such polymers can also be subject to degradation after processing into a profile or the like, for example due to temperature influences or UV radiation. It is therefore necessary, for the purposes of processing and later use, to mix in processing aids and modifiers or additives in general, which are tailored to the processing and the later intended use.

PVC in particular can be provided as a dry blend for further processing into profiles such as window sills or other products. In addition to the plastic or PVC, a dry blend includes the required additives, which can also be admixed to the dry blend in the form of a stabilizer composition with a number of additives.

It is expedient if a stabilizer composition already includes all the necessary components for such purposes, so that no additive or other auxiliary material has to be added to the PVC in a separate step during processing. However, this is not always possible, since different additives have different properties, which make it possible to process them satisfactorily impede or prevent a stabilizer composition that is comprehensive or final in terms of components.

For example, impact modifiers, particularly those based on acrylates such as polybutyl acrylate, are additives that are difficult to incorporate into stabilizer compositions. Although the polybutyl acrylates can be added separately alongside other components when producing a dry blend, this requires a separate metering unit or at least a separate metering step. In addition, acrylates are difficult to handle, due to the risk of dust explosions, because acrylates are very dusty in principle. It would therefore be expedient to add the acrylates, such as polybutyl acrylate, during the production of a stabilizer composition, so that the process step of separate addition and thus also the associated risk potential can be omitted in the later production of a dry blend. However, when preparing stabilizer compositions from the melt, there is no dispersion of the acrylates, such as polybutyl acrylate, due to the high viscosity, which consequently leads to an undesirable formation of specks. If, alternatively, a powder mixture is created, i.e. if the individual components are processed without being in a molten state in the meantime, specks will also form, but there is also the risk of segregation and thus dusting and a dust explosion.

The object of the invention is to specify a method with which the above problems are eliminated or at least reduced.

Furthermore, it is an object of the invention to specify a stabilizer composition that can be used for polymers or dry blends therefor.

A further object consists in specifying the use of a planetary roller extruder.

The object of the process is achieved if an impact modifier is added to a process of the type mentioned at the outset. This can be in particular be an acrylate which acts as an impact modifier, for example a polybutyl acrylate and/or another polymeric acrylate and/or an acrylate-containing copolymer.

An impact modifier is understood to mean any component which, when admixed to a final polymer, is able to ensure higher notched impact strength. As a rule, this is also a polymer. Acrylate-containing impact modifiers in particular are to be understood as meaning polymers and copolymers which contain acrylic monomers and/or acrylic monomer derivatives and/or combinations of acrylic monomer and acrylic monomer derivatives as monomer building blocks. Examples of acrylic monomer derivatives include, but are not limited to: acrylate compounds, which may also contain other elements such as nitrogen, sulfur or halogens, and/or functional groups such as aromatics, hydroxyls or cyano groups, for example methacrylate, methyl methacrylate, butyl acrylate, cyanoacrylate, acrylonitrile or hydroxyalkyl methacrylate.

The concept according to the invention consists in particular in the fact that an impact modifier such as an acrylate can be admixed during the production of a stabilizer composition in an extruder from which extrusion is carried out continuously, without the formation of specks or other disadvantageous demixing. Due to a dust-free, homogeneous and effective dispersion of the impact modifier and the associated good distribution of the same, a very good effect of the stabilizer composition is also achieved when the same is used later. Due to this improved effect, the amount of impact modifier required can also be minimized, which is a great advantage, especially with materials that are difficult to handle, such as acrylates. Furthermore, when the stabilizer composition is used for a dry blend or when a polymer such as PVC is processed, there is no need to add an impact modifier separately. Since processing in an extruder is unproblematic, the risk of a dust explosion is not just shifted to an upstream process step, but is actually completely eliminated. As mentioned, an aggregate such as polybutyl acrylate can be incorporated as an impact modifier. Of course, other impact modifiers, which have similar problems, can also be added accordingly. It is particularly preferred that the impact modifier is admixed in the production of the additive system, viewed in the direction of extrusion, downstream in a last third of the extruder. As a result, the impact modifier is only processed in a limited part of the extruder, namely the rear third, which is important in relation to a necessary but gentle shear stress. This is thereby minimized in some areas, but is sufficient for the impact modifier to be sufficiently incorporated. However, if the acting shearing forces are low and/or only locally limited, an impact modifier such as a polybutyl acrylate or other acrylates is also prevented from gelling, which is a problem, for example, in the aforementioned melting process in the production of stabilizers.

If an extruder with a plurality of sections arranged one behind the other is used, it is expedient for the impact modifier to be added in a last section. In particular, the individual sections can be directly connected to one another, but represent separate units that can be adjusted separately with regard to temperature and shearing forces as well as other process parameters. For the reasons explained above, the impact modifier is then effectively prevented from gelling.

Provision can also be made for the extrusion to be carried out with shear forces which decrease downstream. The shearing forces can decrease continuously or also discretely. For a decrease in shear forces downstream, it is sufficient that at a single point the shear force decreases against the shear force at a preceding point upstream in the extruder.

Although not mandatory, it can also be provided that the impact modifier is added as the last component. The other components of the stabilizer composition are then already at least largely mixed and can then absorb the impact modifier, for which a maximum volume is then available for distribution within the rest of the stabilizer composition, which is advantageous in order to prevent dust formation in the extruder itself as far as possible.

After leaving the extruder, the stabilizer composition can be granulated. The stabilizer composition can be granulated under water. Alternatively it is also possible, and for many applications also preferred, if the stabilizer composition is granulated in air or with air or gas cooling, because the stabilizer composition can certainly also comprise one or more water-soluble components such as calcium acetylacetonate.

Since the stabilizer composition is in principle extruded from the extruder without pressure, it may be necessary for efficient granulation that the stabilizer composition is subjected to pressure downstream of the extruder for granulation. For this purpose, for example, the pressure can be generated with a corresponding pump, which applies pressure to the stabilizer composition to a perforated plate downstream of the extruder, so that the stabilizer composition under pressure hits the perforated plate, passes through it and is then cut to granulate form.

A planetary roller extruder is particularly preferably used as the extruder. With a planetary roller extruder, the shearing forces can be set in a targeted manner, which is beneficial in terms of effective incorporation of the impact modifier and prevention of gel formation.

In particular, a planetary roller extruder with a plurality of modules, preferably at least three modules, in particular four to eight modules, can be used. A planetary roller extruder with several modules has the advantage that the individual modules can be temperature-controlled separately, so that desired temperatures or temperature ranges can be set along the extruder depending on individual reactions or mixing processes and, if necessary, the release of water. In this case, shearing forces can also be varied and thus adjusted in the individual modules. The number of modules is preferably kept in such a way that it is matched to the stabilizer composition to be produced or the components required for this. Basically, the components are extruded in a temperature range of about 80 °C to 240 °C. It is preferably provided that the temperature is initially set to rise and then fall again downstream along the planetary roller extruder. A higher temperature at the start of the planetary roller extruder or the extrusion process is required in order to partially melt the components and thus ensure intimate mixing. Towards the end of the extrusion process, when, for example, a premix and/or temperature-sensitive pigments are added, the temperature is preferably set to be lower again. In this lowered area, the impact modifier is then also added as the last component, if necessary, so that this too is only subject to a low temperature load.

It is further preferred that the shearing forces in the planetary roller extruder are set to decrease downstream, in particular by reducing the number of planetary rollers in the planetary roller extruder downstream. This can easily be achieved in that, for example, in a last module of the

Planetary roller extruder is provided with a smaller number of planetary spindles than in the modules before. In this aspect, too, a planetary roller extruder is excellently suited for processing a stabilizer composition with an impact modifier.

If several modules are provided for a planetary roller extruder, typical temperature ranges can be selected according to Table 1 below.

Table 1: Temperature ranges of individual modules when processing a stabilizer composition in a planetary roller extruder

A stabilizer composition, as produced by a method according to the invention, represents a further aspect of the invention. A stabilizer composition according to the invention is characterized in particular by the fact that an impact modifier, which would only have to be added later during the production of a dry blend or a polymer product made of PVC or another polymer, is already a component of the stabilizer composition and is present homogeneously and in finely divided form can.

The stabilizer composition is preferably free of heavy metals except for small amounts of zinc or zinc salts. In one variant, the stabilizer composition according to the invention contains no lead, apart from any impurities resulting from the production process.

A stabilizer composition can in particular comprise the components described below, which are advantageously mixed or partially reacted before the impact modifier is produced. Unless otherwise stated, percentages (%) are based on weight percent.

The stabilizer composition according to the invention, which is particularly free of heavy metals apart from a small proportion of zinc, can generally be supplemented with one or more additives, such as primary stabilizers, co-stabilizers, zeolites, antioxidants, fillers, plasticizers, dyes, pigments, antistatic agents, surface-active agents, foaming agents, (additional ) impact modifiers, UV stabilizers, lubricants, processing aids and/or the like.

Examples of stabilizers in general are epoxides and epoxidized fatty acid esters, phosphites, thiophosphites and thiophosphates, polyols, 1,3-dicarbonyl compounds, mercaptocarboxylic acid esters, dihydropyridines, antioxidants, light stabilizers and UV absorbers, alkali and alkaline earth metal compounds, perchlorate salts, zeolites, hydrotalcites or dawsonites.

If not already included, other common additives, especially those for PVC, e.g. B. lubricants, plasticizers, other impact strength modifiers, processing aids, blowing agents, fillers, antistatic agents, biocides, antifogging agents, Pigments and dyes, metal deactivators and flame retardants (see "Handbook of PVC Formulating" by EJ Wickson, John Wiley & Sons, New York 1993) and can also be added to the stabilizer composition.

Examples of components for 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). Below are some listings of such components, which are purely exemplary.

As phosphites, in particular as co-stabilizers for chlorine-containing polymers, for example trioctyl, tridecyl, tridodecyl, tritridecyl, tripentadecyl, trioleyl, tristearyl, triphenyl, tricresyl, trisnonylphenyl, tris-2, 4-t-butyl-phenyl or tricyclohexyl phosphite.

Various other phosphites such as various mixed aryl-dialkyl or alkyldiaryl phosphites such as phenyldioctyl, phenyldidecyl, phenyldidodecyl, phenylditridecyl, phenylditetradecyl, phenyldipentadecyl, octyldiphenyl,

Decyldiphenyl, undecyldiphenyl, dodecyldiphenyl, tridecyldiphenyl, tetradecyldiphenyl, pentadecyldiphenyl, oleyldiphenyl, stearyldiphenyl and dodecylbis-2,4-di-t-butylphenyl phosphite may also find utility.

In addition, phosphites of various diols or polyols can also be used advantageously, for example tetraphenyldipropylene glycol diphosphite, polydipropylene glycol phenyl phosphite, tetramethylolcyclohexanol decyl diphosphite,

T etramethylolcyclohexanol-butoxyethoxy-ethyldiphosphit, T etramethylolcyclohexanol- nonylphenyldiphosphit, Bis-nonylphenyl-di-trimethylolpropandiphosphit, Bis-2-butoxyethyl- di-trimethylolpropandiphosphit, Trishydroxyethylisocyanurat-hexadecyltriphosphit, Didecylpentaerythritdiphosphit, Distearylpentaerythritdiphosphit, Bis-2,4-di-t- butylphenylpentaerythritdiphosphit. Mixtures of these phosphites and aryl/alkyl phosphite mixtures can also be used in a stabilizer composition according to the invention. The organic phosphites can be used in an amount of, for example, 0.01 to 10, suitably 0.05 to 5, in particular 0.1 to 3 parts by weight, based on 100 parts by weight of polymer (e.g. PVC).

Examples of polyols that can be used are: pentaerythritol, dipentaerythritol, tripentaerythritol, bistrimethylolpropane, trimethylolethane, bistrimethylolethane, trimethylolpropane, sorbitol, maltitol, isomaltitol, lactitol, lycasine, mannitol, lactose, leucrose, tris-(hydroxyethyl)-isocyanurate, tetramethylolcyclohexanol (TMCH) , tetramethylolcyclopentanol, tetramethylolcyclopyranol, glycerol, diglycerol, polyglycerol, thiodiglycerol, 1-0-a-D-glycopyranosyl-D-mannitol dihydrate as well as polyvinyl alcohol and cyclodextrins. Of these, preference is given to TMCH and the disaccharide alcohols. The polyols can be used in an amount of, for example, 0.01 to 20, suitably 0.1 to 20, in particular 0.1 to 10 parts by weight, based on 100 parts by weight of polymer (e.g. PVC).

Thiophosphites or thiophosphates are compounds of the general type (RS)sP, (RS) ₃ P=0 or (RS)3P=S. Exemplary compounds are trithiohexyl phosphite, trithiooctyl phosphite, trithiolauryl phosphite, trithiobenzyl phosphite, trithiophosphoric acid tris-[carboxy-i-octyloxy]-methyl ester, trithiophosphoric acid-S,S,S-tris-[carbo-i-octyloxy]-methyl ester, trithiophosphoric acid-S, S,S-tris-[carbo-2-ethylhexyloxy]-methyl ester, trithiophosphoric acid-S,S,S,-tris-1-[carbo-hexyloxy]-ethyl ester, trithiophosphoric acid- S,S,S-tris-1-[ carbo-2-ethylhexyloxy]ethyl ester, trithiophosphoric acid S,S,S-tris-2-[carbo-2-ethylhexyloxyethyl ester. The thiophosphites or thiophosphates can expediently be present at 0.01% to 20%, preferably at 0.1% to 5%, in particular at 0.1% to 1% in the particularly chlorine-containing polymer (e.g. PVC).

Examples of 1,3-dicarbonyl compounds are acetylacetone, butanoylacetone, heptanoylacetone, stearoylacetone, palmitoylacetone, lauroylacetone, 7-tert-nonylthioheptanedione-2,4, benzoylacetone, dibenzoylmethane, lauroylbenzoylmethane, palmitoylbenzoylmethane, stearoylbenzoylmethane, isooctylbenzoylmethane, 5-hydroxycapronyl - benzoylmethane, tribenzoylmethane, bis(4-methylbenzoyl)methane, benzoyl-p-chlorobenzoylmethane, bis(2-hydroxybenzoyl)methane, 4-methoxybenzoylbenzoylmethane, 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, Di(pivaloyl)methane, methyl, ethyl, hexyl, octyl, dodecyl or octadecyl acetoacetate, ethyl, butyl, 2-ethylhexyl, dodecyl or octadecyl benzoylacetate, ethyl, propyl or butyl stearoyl acetate -, - hexyl or -octyl esters and dehydroacetic acid and their zinc, alkali metal, alkaline earth metal and/or aluminum salts. The 1,3-dicarbonyl compounds can be used in an amount of, for example, 0.01 to 10, suitably 0.01 to 3, in particular 0.01 to 2 parts by weight, based on 100 parts by weight of polymer (e.g. PVC).

Examples of mercaptocarboxylic acid esters which may be mentioned are: esters of thioglycolic acid, thiomalic acid, mercaptopropionic acid, mercaptobenzoic acids or thiolactic acid, such as are described, for example, in EP 0 365483 A1.

The mercaptocarboxylic acid esters also include corresponding polyol esters or their partial esters. The corresponding esters can expediently be present at 0.01% to 10%, preferably at 0.1% to 5%, in particular at 0.1% to 1%, in a polymer which in particular contains chlorine.

A stabilizer composition according to the invention may additionally contain at least one epoxidized fatty acid ester. Esters of fatty acids from natural sources such as soybean oil or rapeseed oil are preferred. The epoxy compounds are used in amounts of, for example, from 0.1 part, based on 100 parts by weight of composition, advantageously from 0.1 to 30, in particular from 0.5 to 25, parts by weight. Other examples are epoxidized polybutadiene, epoxidized linseed oil, epoxidized fish oil, epoxidized tallow, methylbutyl or 2-ethylhexyl epoxy stearate, 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 used as epoxides.

Furthermore, monomeric dihydropyridines and/or polydihydropyridines can be provided as stabilizers, as disclosed in EP 0 796888 A2. The (poly)dihydropyridines can be used in the polymer, in particular one containing chlorine, expediently in amounts of from 0.001 to 5, in particular from 0.005 to 1, parts by weight, based on the polymer with 100 parts by weight. Furthermore, sterically hindered amines can be provided as stabilizers, as are also disclosed in EP 0796 888 A2.

A stabilizer composition according to the invention can contain alkali metal and alkaline earth metal compounds, in particular the carboxylates of the acids described above, but also corresponding oxides or hydroxides, carbonates or basic carbonates. Their mixtures with organic acids are also suitable. Examples are NaOH, KOH, CaO, Ca(OH) 2 , MgO, Mg(OH) 2 , CaCO ₃ , MgCO _ß , 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, their adducts with MO or M(OH) 2 (M=Ca, Mg, Sr or Zn), so-called "overbased" compounds, can also be used. Alkali is additionally preferred for a stabilizer according to the invention -, Alkaline earth and / or aluminum carboxylates used, for example sodium, potassium, calcium or aluminum stearates.

The stabilizer composition can, for example, comprise one or more perchlorate salts, for example those of the general formula M(Cl0 ₄ ) _n , where M is Li, Na, K, Mg, Ca, Ba, Zn, Al, Ce or La. The index n runs from 1 to 3, depending on the value of M, and is therefore 1, 2 or 3. The perchlorate salts can be complexed with alcohols or ether alcohols. The respective perchlorate can be used in various common dosage forms, e.g. B. as a salt or aqueous solution mounted on a carrier material such as PVC, calcium silicate, zeolite or hydrotalcite, or obtained by chemical reaction of hydrotalcite with perchloric acid.

Alternatively or additionally, phyllosilicates intercalated with perchlorate, such as hydrotalcites, can also be used. Exemplary compounds from this group are Alcamizer® products from Kisuma Chemicals. The perchlorates can be used in an amount of, for example, 0.001 to 5, suitably 0.01 to 3, particularly preferably 0.01 to 2 parts by weight, based on 100 parts by weight of PVC or other polymer.

Co-stabilizers are compounds that can make a further stabilizing contribution to halogen-containing polymers. Possible co-stabilizers can be selected from the group consisting of 1,3-diketone compounds, polyols, metal salts, natural or synthetic minerals such as hydrotalcite, hydrocalumite and zeolite, amino acid derivatives, organic esters of phosphorous acid, epoxy compounds.

Examples of 1,3-diketone compounds include, but are not limited to, dibenzoylmethane, stearoylbenzoylmethane, palmitoylbenzoylmethane, myristoylbenzoylmethane, lauroylbenzoylmethane, benzoylacetone, acetylacetone, tribenzoylmethane, diacetylacetobenzene, p-methoxystearoylacetophenone, acetoacetic acid ester and acetylacetone and their metal salts, especially those of lithium , sodium, potassium, calcium, magnesium, titanium and/or aluminum.

Co-stabilizers from the group of polyols include, but are not limited to, glycerol, pentaerythritol, di- and tri-pentaerythritol, trismethylolpropane (TMP), di-TMP, sorbitol, mannitol, malititol, saccharides, disaccharides (especially sucrose, 4- O-ß-D-galactopyranosyl-D-glucose, 4-0-alpha-D-glucopyranosyl-D-glucose, 6-0-(6-deoxy-alpha-L-mannopyranosyl)-D-glucose, alpha-D- Glucopyranosyl- alpha-D-glucopyranoside, 6-O-alpha-D-glucopyranosyl-D-glucose, 4-O-ß-D-glucopyranosyl-D-glucose, 2-0-ß-D-glucopyranosyl-D-glucose, 6-O-alpha-D- glucopyranosyl-D-glucitol, 3-O-alpha-D-glucopyranosyl-D-fructose, 6-O-ß-D- glucopyranosyl-D-glucose, 4-O-ß-D- galactopyranosyl-D-glucitol, 4-O-alpha-D-glucopyranosyl-D-glucitol, 6-O-alpha-D-galactopyranosyl-D-glucose, 3-O-alpha-D-galactopyranosyl-D-myo-inositol, 4-0-ß-D-galactopyranosyl-D-fructose, 4-O-ß-D-galactopyranosyl-ß-D-glucopyranose, ß-O-alpha-D-glucopyranosyl-D-fructose, 4-0-ß- D-galactopyranosyl-alpha-D-glucopyranose, 2-0-(6-deoxy-alp ha-L-mannopyranosyl)-D-glucose, 4-O-alpha-D-glucopyranosyl-D-fructose, 2-O-β-D-glucopyranosyl-alpha-D-glucopyranose, 1-O-alpha-D-glucopyranosyl -D-mannitol, 6-0-(6-deoxy-alpha-L-mannopyranosyl)-ß-D-glucopyranose, 2-0-ß-D-glucopyranosyl-ß-D-glucopyranose, 6-0-alpha-D -glucopyranosyl-alpha-D-glucopyranose, 2-O-alpha-D-glucopyranosyl-alpha-D-glucopyranose, 2-O-alpha-D-glucopyranosyl-ß-D-glucopyranose, 1-O-alpha-D-glucopyranose -D-fructose, 6-0-alpha-D-glucopyranosyl-alpha-D-fructofuranose, 6-0-alpha-D-glucopyranosyl-D-glucitol, 4-O-ß-D-galactopyranosyl-D-glucitol, 4 -O-alpha-D-glucopyranosyl-D-glucitol, 1-O-alpha-D-glucopyranosyl-D-mannitol, trisaccharides, polysaccharides, in particular polyvinyl alcohols, starch, cellulose and their partial esters. Examples of antioxidants include, but are not limited to, alkylphenols, hydroxyphenylpropionates, hydroxybenzyl compounds, alkylidenebisphenols, thiobisphenols and aminophenols, especially e.g. B. 2,6-di-tert-butyl-4-methyl-phenol, 2,6-di-benzyl-4-methyl-phenol, stearyl-3-(3'-5'-di-tert-butyl). -4'-hydroxy-phenyl)propionate, 4,4'-thiobis(3-methyl-6-tert-butyl-phenol), 4-nonylphenol, 2,2'-methylenebis(4-methyl-6-tert .-butylphenol), 2,5-di-tert-butylhydroquinone, 4,4',4"-(l-methyl-l-propanyl-3-ylidene)tris[2-(1,1-diethylethyl)- 5-ethyl-phenol], their neutral or basic lithium, magnesium, calcium and aluminum salts, and also sterically hindered amines and/or phosphonites and mixtures thereof.

Examples of metal salt co-stabilizers include, but are not limited to, hydroxides, oxides, carbonates, basic carbonates, and carboxylic acid salts of lithium, sodium, potassium, magnesium, calcium, aluminum, titanium, and the like, so long as (excluding zinc ) no heavy metal is used. In one embodiment of the present invention, the metal salts may be salts of higher carboxylic acids, for example C6-C22 carboxylic acids, such as stearic, palmitic, myristic, lauric, oleic, oleic and ricinoleic acid.

Examples of natural and synthetic minerals include, but are not limited to, A3, A4, A5 zeolites, mordenite, erionite, faujasite X or Y type zeolites, and ZSM-5 zeolites, hydrotalcites (from Alcamizer® 1 and 4-type) and/or mixtures thereof.

Mesoporous materials, in particular mesoporous silicates such as MCM-41 or SBA-15, can also represent components of a stabilizer composition according to the invention.

Examples of amino acid derivative co-stabilizers include, but are not limited to, glycine, alanine, lysine, tryptophan, acetylmethionine, pyrrolidone carboxylic acid, α-aminocrotonic acid, α-aminoacrylic acid, α-aminoadipic acid and the like, and the corresponding esters thereof. The alcohol components of these esters can be monohydric alcohols, e.g. methyl alcohol, ethyl alcohol, propyl alcohol, i-propyl alcohol, butyl alcohol, a-ethylhexanol, octyl alcohol, i-octyl alcohol, lauryl alcohol, stearyl alcohol and the like, and polyols such as e.g. B. ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, glycerol, diglycerol, trismethylolpropane, pentaerythritol, dipentaerythritol, erythritol, sorbitol, mannitol and the like.

Examples of phosphorous acid ester co-stabilizers include, but are not limited to, triaryl phosphites, such as e.g. B. triphenyl phosphite, tris (p-nonylphenyl) phosphite, alkylaryl phosphites, such as. B. monoalkyldiphenyl phosphites, z. B. diphenylisooctyl phosphite, diphenylisodecyl phosphite, and dialkyl monophenyl phosphites, such as. B. phenyldiisooctyl phosphite or phenyl diisodecyl phosphite, and trialkyl phosphites such as triisooctyl phosphite, tristearyl phosphite and the like.

Another component which can be included in the stabilizer composition of the invention is titanium dioxide. Titanium dioxide essentially occurs naturally in three modifications: anatase, brookite and rutile. Both anatase and rutile have technical importance as pigments. The high refractive indices of 2.55 (anatase) and 2.75 (rutile) justify the brightening and hiding power and thus its use as a white pigment. With the appropriate dosage, rutile completely absorbs light below 400 nm, i.e. the entire UV range. The absorption of anatase is slightly shifted to shorter wavelengths. Brookite, on the other hand, does not show any photocatalytic activity and is therefore not preferred as another component of the stabilizer composition, but can be added as a filler.

For exterior applications, the titanium dioxide advantageously has a rutile structure. For all other applications, it can have both anatase and rutile structure. Combinations of these modifications are also possible.

The titanium dioxide can be used in accordance with the present invention in an amount of from about 0.01% to about 20% in the stabilizer composition. In another embodiment, the titanium dioxide can be used in an amount of from about 0.05% to about 10.0%, or from about 0.1% to about 5%, for example in an amount of about 4%. The titanium dioxide should be finely divided and well dispersed. Paraffin wax can be used as a lubricant, for example. In one embodiment, the paraffin wax can be a mixture of alkanes having the general molecular 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 as well as purely straight-chain components. Examples of commercially available and useful paraffin waxes include, but are not limited to, Fischer-Tropsch paraffins and related compounds.

Fillers can be provided as part of a stabilizer composition, but are not necessarily part of it.

The other co-stabilizers specified above can be used in identical amounts to the lubricants.

In order to process halogen-containing polymers with the stabilizer composition produced according to the invention, the methods known in the prior art can be used. Examples of such methods include, but are not limited to, calendering, extrusion, injection molding, blow molding, and the like. The composition according to the invention can also be admixed to a dry blend which is subsequently processed further to give a product which is at least close to the final dimensions.

Polymers can be made into products for different applications from the stabilizer composition according to the invention. For example, window profiles, pipes, floor coverings, roofing membranes, cables and foils can be produced with the appropriately stabilized polymers. The polymers can also be foamed or foamed during processing. In addition, the polymers can be used in materials for sports boats, rotor blades for wind turbines and in wagon construction, to name just a few examples. All of these applications are only examples, without the use of a stabilizer composition according to the invention being limited in any way. The task of specifying the use of a planetary roller extruder is achieved if a planetary roller extruder is used to produce a stabilizer composition, shear forces being adjusted via a different number of planetary spindles in modules of the planetary roller extruder.

When used in this way, it is advantageous that otherwise high-quality stabilizer compositions that can only be produced with difficulty or with insufficient quality properties can be provided, if at all. In particular, if the individual modules can also be temperature-controlled separately, the conditions for mixing can be optimized, optionally with a reaction taking place at the same time.

Further features, advantages and effects of the invention result from the exemplary embodiments presented below. In the drawing shows:

1 shows a planetary roller extruder.

1 shows an extruder which is used in the processing or production of a stabilizer composition according to the invention. The extruder is a planetary roller extruder 1.

The planetary roller extruder has a first end 2 and a second end 3 opposite the first end 2 . The planetary roller extruder 1 is composed of several modules 10, 11, 12, 13, 14, 15, 16. Each of these modules 10, 11, 12,

13, 14, 15, 16 is each equipped with a circuit 10a, 11a, 12a, 13a, 14a, 15a, 16a with heating and/or cooling function. A fluid, in particular an oil, can be circulated in these circuits 10a, 11a, 12a, 13a, 14a, 15a, 16a in order to bring the individual modules 10, 11, 12, 13, 14, 15, 16 to a desired temperature or to be kept at this temperature during processing of a composition. If necessary, temperature changes can also be carried out. A similar circuit p is provided for tempering a spindle 4 .

A spindle 4 of the planetary roller extruder 1 passes through the modules 10 , 11 , 12 , 13 , 14 , 15 , 16 . The spindle 4 is the central drive element. On the outside is the spindle 4 surrounded by a large number of planetary spindles, which cannot be seen, as is usual for a planetary roller extruder 1 . The number of planetary spindles, which are arranged around the spindle 4 within the modules 10, 11, 12, 13, 14, 15, 16, can be varied for the individual modules 10, 11, 12, 13, 14, 15, 16 . Typically, three, five or seven planetary spindles are provided in each module 10, 11, 12, 13, 14, 15, 16. Furthermore, the planetary roller extruder 1 can be divided between individual modules 10, 11, 12, 13,

14, 15, 16 include dispersing disks 8 and a degassing disk 9 downstream.

The spindle 4 is connected to a motor, not shown, which can cause the spindle 4 to rotate. The spindle 4 runs at a freely selectable rotational speed, e.g. typically at rotational speeds between 200 rpm and 400 rpm with an internal diameter of the extruder of 100 mm to 120 mm and a central spindle diameter of 70 mm to 75 mm. Rotational speeds in the range from about 275 rpm to 375 rpm have proven particularly useful for the extruder dimensions given as an example. Shearing forces in the modules 10, 11, 12, 13, 14, 15, 16 can be set via the rotational speed on the one hand and a number of planetary spindles, which are arranged around the spindle 4, which allows this, as will be explained below Otherwise, to create stabilizer compositions that cannot be produced or can only be produced with unsatisfactory results.

The planetary roller extruder 1 according to FIG. 1 also has a number of outlets 5 , 6 , 7 . The outlets 5, 6, 7 do not necessarily have to be provided, but they are favorable and expedient when a stabilizer composition is processed which tends to form a lot of foam during processing. This is the case, for example, when stabilizer compositions containing fatty acids or derivatives are processed, with water being released during their reaction. The outlets 5, 6, 7, which are arranged on an upper side of the housing of the individual modules 10, 11, 12, 13, 14, 15, 16 of the planetary roller extruder 1, are preferably rectangular in cross section. In particular, the outlets 5, 6, 7 can be cuboid or slit-shaped and extend upwards, through which controlled foaming with release of water is possible without the stabilizer composition to be processed escaping. Rather, there is only an escape of water while the processing stabilizer composition is propelled downstream towards the second end 3 by the spindle 4 in cooperation with the associated planetary spindles.

For the production of a stabilizer composition, the planetary roller extruder 1 must be fed in a suitable manner. Individual supply devices or feeders 21, 22, 23, 24, 25, 26 can be provided for this purpose. In the corresponding feeders 21, 22, 23, 24, 25, 26, the task of individual components for the production of the stabilizer composition takes place, with a supply in relation to the temperature of the modules 10, 11, 12, 13, 14, 15, 16, shear forces and degree of homogenization of the stabilizer components can be adjusted.

During the production of a stabilizer composition, the individual modules 10, 11, 12, 13, 14, 15, 16 are temperature-controlled separately via the circuits 10a, 11a, 12a, 13a, 14a, 15a, 16a. Table 2 below lists typical temperatures for individual modules when producing a stabilizer composition, the stabilizer composition being created with an impact modifier. The temperature of the melt pump relates to a pump downstream of the extruder for pressurizing the discharged stabilizer composition.

Table 2: Circuit temperatures of individual modules

When producing a stabilizer composition with an impact modifier in a planetary roller extruder 1, the individual components for the stabilizer composition are first fed into one or more of the feeders 21, 22, 23, 24, 25, but not the impact modifier. A corresponding composition with a premix according to Table 4 is given in Table 3 below. The modules 10, 11, 12, 13, 14, but not the module 16, are each operated with five planetary spindles. A typical speed of rotation of the spindle 4 is 300 rpm. Module 16 and optionally module 15 are only operated with three planetary spindles. A premix containing an impact modifier such as an acrylate, in particular polybutyl acrylate, is fed into the modules 15, 16 via the feeder 25 and/or the feeder 26. As mentioned, the composition of the premix can be seen from Table 4 below.

Table 3: Exemplary composition for a stabilizer composition based on 1000 kg output (10.7 kg escaping residual water taken into account, all bases react with the acids)

Table 4: Composition of a premix (see Table 3) based on 1000 kg of stabilizer composition

Components 1 to 4 of the stabilizer composition, with the exception of the premix, can be fed into modules 10, 11, 12, in particular stearic acid. Hydroxystearic Acid, Zinc Oxide and Calcium Hydroxide. Downstream thereafter, magnesium hydroxide and acetic acid may be fed to react. In modules 12,13,

A conversion and mixing can then take place in 14 before the premix is supplied in module 15 and/or in module 16 . The temperature control (see Table 2) leads to the melting of the fatty acids. The fatty acids react to form soaps or salts of the corresponding acids, the conversion of which is or will be completed by module 13. In the present example, the premix is fed into module 15, module 16 is used for temperature control in preparation for subsequent underwater granulation.

After mixing the premix in module 15 with the other components of the stabilizer composition already present in this module 15, a stabilizer composition is discharged at the second end 3, which can be pressurized with a pump in the direction of a downstream perforated plate, so that the stabilizer composition passes through the perforated plate is pressed and cutting to length can take place. A corresponding granulation can, for example, take place under water, but also in air. Is then obtained granular stabilizer, which

Contains impact modifier and can be added to a dry blend as a completely finished stabilizer composition, but can also be used for directly creating a profile from a polymer, in particular a profile made from PVC.

The resulting stabilizer product containing an impact modifier is designated P1. For comparison, all components 1 to 4 from Table 3 were reacted in a conventional batch process in a reactor and after the reaction to the corresponding soaps or salts was complete, components A to G were added to the melt in a suitable order and the comparative product V1 shaped as a tablet.

The comparison of the product P1 according to the invention with the comparative product, which was produced by conventional batch processes without the possible incorporation of an impact modifier, is given in Table 5.

A dry blend is produced with PVC and additional filler and the respective dry blend is extruded to form profile samples. These profile samples were subjected to a notched bar impact test. The higher impact energy value of the sample prepared according to the invention shows the unexpected benefit.

Table 5: Composition of the extruded profile samples Various test series have shown that the quality of a created

Stabilizer composition, which immediately has an impact modifier added, can be achieved through targeted adjustment of the shear forces. By using a planetary roller extruder 1, it is possible to increase the shear forces during production via the rotational speed of the spindle 4 and a number of planetary spindles optimize that the best possible mixing or homogenization takes place for the individual components. This applies in particular to the impact modifier, which is only added or supplied at a relatively late stage, namely in the last third or at most the last module 16 of the stabilizer composition. A smaller number of planetary spindles results in lower shearing forces, so that unwanted gelation or specks formation is prevented and a stabilizer composition of high quality can be obtained.

Claims

patent claims

1. A process for producing a stabilizer composition for a polymer, in particular a halogen-containing polymer such as polyvinyl chloride, wherein components for forming the stabilizer composition are mixed in an extruder and continuously discharged from this, characterized in that an impact modifier is added.

2. The method according to claim 1, characterized in that an acrylate is added as an impact modifier.

3. The method according to claim 1 or 2, characterized in that the impact modifier viewed in the direction of extrusion is admixed downstream in a last third of the extruder.

4. The method according to any one of claims 1 to 3, characterized in that an extruder with a plurality of sections arranged one behind the other is used and the impact modifier is added in a last section.

5. The method according to any one of claims 1 to 4, characterized in that the

Extrusion is carried out with downstream decreasing shear forces.

6. The method according to any one of claims 1 to 5, characterized in that the impact modifier is added as the last component.

7. The method according to any one of claims 1 to 6, characterized in that the stabilizer composition is granulated after leaving the extruder.

8. The method according to claim 7, characterized in that the stabilizer composition is granulated in air.

9. The method according to claim 7 or 8, characterized in that the stabilizer composition is subjected to pressure after the extruder for the granulation.

10. The method according to any one of claims 1 to 9, characterized in that a planetary roller extruder (1) is used as the extruder.

11. The method according to claim 10, characterized in that a planetary roller extruder (1) with a plurality of modules (10, 11, 12, 13, 14, 15, 16), preferably at least three modules (10, 11, 12, 13, 14, 15, 16), in particular four to eight modules (10, 11, 12, 13, 14, 15, 16).

12. The method according to claim 10 or 11, characterized in that the components are extruded in a temperature range of about 80 °C to 240 °C.

13. The method according to any one of claims 10 to 12, characterized in that along the planetary roller extruder (1) downstream the temperature is initially set to rise and then fall again.

14. The method according to any one of claims 10 to 13, characterized in that the shear forces in the planetary roller extruder (1) are set to decrease downstream, in particular by reducing the number of planetary rollers in the planetary roller extruder (1) downstream.

15. Stabilizer composition obtainable according to any one of claims 1 to 14.

16. Use of a planetary roller extruder (1) for producing a stabilizer composition, shear forces being adjusted via a different number of planetary spindles in modules (10, 11, 12, 13, 14, 15, 16) of the planetary roller extruder (1).