WO2023025638A1

WO2023025638A1 - Antistatic masterbatch based on thermoplastic polyurethan with improved properties for the use in polymers

Info

Publication number: WO2023025638A1
Application number: PCT/EP2022/072989
Authority: WO
Inventors: Marcus Harald BLUEMEL; Frank Schaefer; Anja OLTMANNS; Alexandra WORMSTALL
Original assignee: Basf Se
Priority date: 2021-08-27
Filing date: 2022-08-17
Publication date: 2023-03-02

Abstract

:The invention is directed to an antistatic masterbatch comprising thermoplastic polyurethane, where the thermoplastic polyurethane is prepared from an isocyanate, a polyol comprising a diol A comprising ethoxy and propoxy groups and a diol B comprising butoxy groups, and a chain extender, wherein a perchlorate is comprised in the composition. Further aspects of the inventions are blends made with this masterbatch, respective production processes and the use of the masterbatch.

Description

Antistatic masterbatch based on thermoplastic polyurethan with improved properties for the use in polymers

The current invention is directed to an antistatic masterbatch for the use in polymers with improved properties.

Additives for lowering the surface resistance and respective antistatic polymers are well known. EP2170972 A1 and EP3058009 A1 describe ionic liquids as antistatic agents for thermoplastic polyurethane (TPU). EP 3 058 009 A1 and PCT/EP 2021 1059230 describe antistatic thermoplastic polyurethanes (TPU) are blended with other polymers to equip them with antistatic properties.

However, the problem of these blends is that they quickly lose their conductivity when exhibited to the influence of water or sun light, Therefore, there is an ongoing need for antistatic additives, which are more resistant to these influences.

Surprisingly thermoplastic polyurethane with perchlorate ensures low surface resistance of the blend even after weathering.

The invention further provides a process for producing the composition of the invention, the use of the composition of the invention as conductivity improver and the thermoplastic polyurethane specifically developed for use as conductivity improver.

A conductivity improver is understood as a substance, or a polymer composition added to a polymer for improving the conductivity of this polymer compared to the polymer not comprising the conductivity improver. Preferably the conductivity of the polymer is determined by measuring the surface resistivity, preferably according to DIN EN 62631-3-2:2018-09, more preferably at 23 °C and 72% rel. humidity. The surface conductivity is the inverse of the surface resistivity. Preferably, the conductivity enhancer is a substance or a polymer composition reducing the specific surface resistivity for at least a factor 2, preferably 5, more preferably 10.

A first aspect and embodiment 1 of the invention is a composition comprising a thermoplastic polyurethane, where the thermoplastic polyurethane is prepared from a) an diisocyanate, b) a polyol, preferably a diol comprising a diol A comprising ethoxy and propoxy groups and a diol B comprising butoxy groups, and c) a chain extender, optionally with the aid of a catalysts, and optionally further comprising additives and/or auxiliaries, wherein a perchlorate is comprised in the composition. The term composition indicates that the composition does not comprise the polyurethane only, but may comprise several polymers, additives and/or auxiliaries.

Preferably the thermoplastic polyurethane, is prepared by reacting (a) an organic isocyanate, preferably an diisocyanate, with (b) a compound reactive with isocyanate, in a preferred embodiment a polyol, preferably having two functional groups reactive with isocyanate, also referred to as diol, preferably having a number average molecular weight of from 0.5 x 10³ g /mol to 100 x 10³ g /mol and, if desired, (c) a chain extender preferably having a molecular weight of from 0.05 x 10³ g /mol to 0.499 x 10³ g /mol, if desired in the presence of (d) a catalyst and/or (e) an auxiliary and/or an additive.

The components (a) isocyanate, preferably diisocyanate, (b) compound reactive with isocyanate, in a preferred embodiment polyol, more preferred a diol, and (c) chain extender are also addressed individually or together as structural components. The structural components including the catalyst and/or the auxiliary and/or the additive are also called input materials.

In order to adjust the hardness and melt index of the thermoplastic polyurethane (TPU), the molar ratios of the quantities of the structural components can be varied, whereby the hardness and melt viscosity increase with increasing content of isocyanate or with increasing content of isocyanate and chain extender (c), while the melt flow index decreases.

For the production of polyisocyanate polyaddition product, preferably thermoplastic polyurethanes, preferably those having a Shore A hardness of less than 95, preferably from 95 to 75 Shore A, the essentially difunctional polyols (b), also referred to as diols, and the chain extender (c) may advantageously be used in mole ratios of 1 :1 to 1 :5, preferably 1 :1.5 to 1 :4.5, such that the resulting mixtures of the structural components compound reactive with isocyanate, preferably polyol (b) and chain extender (c) have a hydroxyl equivalent weight of greater than 200, and in particular from 230 to 450, while for the production of harder TPU, e.g. those having a Shore A hardness greater than 98, preferably 55 to 75 Shore D, the molar ratios of compound reactive with isocyanate and chain extender being in the range of 1 :5.5 to 1 :15, preferably 1 :6 to 1 :12, such that the resulting mixtures of compound reactive with isocyanate (b) and chain extender (c) have a hydroxyl equivalent weight of 110 to 200, preferably 120 to 180.

In order to prepare the thermoplastic polyurethane, the structural components isocyanate (a), compound reactive with isocyanate (b), in a preferred embodiment also the chain extender (c), are reacted in preferred embodiments in the presence of a catalyst (d), and optionally auxiliaries and/or additives (e) in such quantities that the equivalent ratio of NCO groups of the isocyanate, preferably the diisocyanates (a) to the sum of the hydroxyl groups of the component reactive with isocyanate (b) and chain extender (c) is 0.95 to 1.10:1 , preferably 0.98 to 1.08:1 and in particular approximately 1.0 to 1.05:1. In a very preferred embodiment the equivalent ratio is 1.0.

Polyisocyanate polyaddition product, preferably thermoplastic polyurethane, has preferably a weight-average molecular weight of at least 0.1x10⁶ g/mol, preferably of at least 0.4 x 10⁶ g/mol and in particular of at least 0.6 x10⁶ g/mol. The upper limit for the weight-average molecular weight of TPU is generally determined by the processability and the desired range of properties. Preferably the weight-average molecular weight does not exceed 0.8 x10⁶ g/mol. The mean molecular weights and the weight-average molecular weight as outlined herein are determined by gel permeation chromatography, preferably according to DIN 55672-1.

Isocyanate

The isocyanate preferably is an organic isocyanate, more preferred is a diisocyanate. Further preferred the isocyanate is selected from the group consisting of aliphatic, cycloaliphatic, arali- phatic and aromatic isocyanates, or is a mixture thereof. The isocyanate more preferably is selected from the group comprising tri-, tetra-, penta-, hexa-, hepta- and/or octamethylene diisocyanate, 2-methyl-pentamethylene 1 ,5-diisocyanate, 2-ethyl-butylene-1 ,4-diisocyanate, 1 ,5-pen- tamethylene diisocyanate (PDI), 1 ,4- butylene-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-iso- cyanatomethyl-cyclohexane (isophorone diisocyanate, IPDI), 1 ,4- bis(isocyanatomethyl)cyclo- hexane and/or 1 ,3-bis(isocyanatomethyl)cyclohexane (HXDI), 2,4-paraphenylene diisocyanate (PPDI), 2,4-tetramethylene xylene diisocyanate (TMXDI), 4,4'-, 2,4'- and 2,2'-dicyclohexylme- thane diisocyanate (H12 MDI), 1 ,6-hexamethylene diisocyanate (HDI),1 ,4-cyclohexane diisocyanate, 1-methyl-2,4- and/or -2, 6-cyclohexane diisocyanate, 2,2'-, 2,4'- and/or 4, 4'-diphenylme- thane diisocyanate (MDI), 1 ,5-naphthylene diisocyanate (NDI), 2,4- and/or 2, 6-toluene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate, 1 ,2-diphenylethane diisocyanate and/or phenylene diisocyanate, or is a mixture thereof.

Aliphatic isocyanates are preferred when stability against electromagnetic waves e.g. light is of importance, whereas aromatic polyisocyanate is preferred when high mechanical strength of the polyurethane, especially the thermoplastic polyurethane is required. A further advantage of aliphatic isocyanate is that it may be produced bio-based.

Aliphatic isocyanates are preferred. Very preferred aliphatic isocyanate are hexamethylene diisocyanate, in particular 1 ,6-hexamethylene diisocyanate (HDI).and pentamethlyenediisocyante, preferably 1 ,5-pentamethylene diisocyanate. This has the additional advantage, that it can be produced bio-based. The most preferred isocyanate is1 ,6 hexa- methylene-diisocyanate.

Polyol

The isocyanate-reactive compound has on statistical average at least 1.8 and at most 3.0 Zere- witinoff-active hydrogen atoms, this number is also referred to as the functionality of the isocyanate-reactive compound and indicates the quantity of the isocyanate-reactive groups of the molecule calculated theoretically down to one molecule from a quantity of substance. The functionality is preferred between 1 .8 and 2.6, further preferred between 1 .9 and 2.2 and especially preferred 2. Compounds reactive with isocyanates are preferably those having a molecular weight between 0.500 g/mol and 8 x10³ g/mol, preferably 0.7 x 10³ g/mol to 6.0 x 10³ g/mol, in particular 0.8 x 10³ g/mol to 4.0 x 10³ g/mol.

The isocyanate-reactive compound is essentially linear and is a single isocyanate-reactive compound or is a mixture of different such compounds, in which case the mixture meets the above requirement.

These long-chain compounds are used with a content of 1 mol% equivalent to 80 mol% equivalent, based on the isocyanate group content of the polyisocyanate.

The compound reactive with isocyanate (b) preferably has a reactive group selected from the hydroxyl group, the amino group, the mercapto group or the carboxylic acid group. The preferred group is the hydroxyl group. These compounds are also referred to as polyol or polyhydroxy polyol. The polyol (b) preferably is selected from the group consisting of polyesterols, polyetherols or polycarbonate diols, more preferred from the group consisting of polyether polyol and polycarbonate. Particularly preferred is polyether polyol. More preferably the polyol is a diol.

According to the invention, the polyol, which preferably is a diol, comprises a diol A comprising ethoxy and propoxy groups, and a diol B comprising butoxy groups,

In a preferred embodiment, the molar percentage of the ethoxy and propoxy groups and butoxy groups in the composition is at least 5 mol%, preferably at least 10 mol%, based on the mole weight of the total diol. Further preference is given to the proportion of ethoxy groups in the diol in the composition at the same time being at least 25 mol%, more preferably at least 40 mol%, more preferably at least 60 mol% and particularly preferably at least 65 mol%, based on the total diol.

Very particular preference is given to the molar percentage of the ethoxy group being in the range from 70 mol% to 75 mol%, the proportion of the propoxy group being in the range from 12 mol% to 18 mol% and the proportion of the butoxy groups being in the range from 12 mol% to 18 mol%, based on the total polyol.

The determination of the molar percentage is carried out by means of ¹H NMR in accordance with ASTM D4875 - 11 (2011) Standard Test Methods of Polyurethane Raw Materials: Determination of the Polymerized Ethylene Oxide Content of Polyether Polyols.

Further preference is given to the diol B in the composition being a homopolymer. A homopolymer is a polymer which is made up of virtually only one monomer group, i.e. essentially does not comprise any other monomers. "Essentially" means that at least 95 mol% of the homopolymer consists of only one monomer, more preferably at least 97.5 mol% and particularly preferably at least 99 mol%. A preferred diol B is polybutylene oxide diol. More preferably diol B is polytetrahydrofuran.

Furthermore, the diol A in the composition is preferably a block copolymer having one block and two ends, with the block comprising ethoxy and propoxy groups and the two ends of the block copolymer comprising exclusively ethoxy groups. In this block polymer, the proportion of ethoxy groups in the two ends of the block copolymer is preferably more than 5 mol%, preferably at least 10 mol% and particularly preferably at least 15 mol%, based on the number average molecular weight of the total block copolymer. The ends of the block copolymer very particularly preferably comprise from 10 mol% to 20 mol% of the ethoxy groups, based on the total block copolymer, and the block of the block copolymer comprises in the range from 60 mol% and 70 mol% of ethoxy groups and in addition from 15 mol% to 20 mol% of propoxy groups, based on the total block copolymer.

Diol A preferably is prepared by adding the desired cyclic alkylene oxides, in the present case ethylene oxide and propylene oxide, to a bifunctional starter molecule in a reactor in a 1st step, so that the cyclic alkylene oxides polymerize with ring opening to form a prepolymer. Preference is given to using starter molecules having two OH groups, which are preferably primary OH groups. Very particularly preferred examples are 1 ,2-ethylene glycol, also referred to as monoethyl glycol (MEG), diethylene glycol (DEG), monopropanediol (MPG), preferably 1 ,3-propyl- ene glycol, and also dipropanediol (DPG), preferably 4-oxa-1 ,7-heptanediol. The structure of the prepolymer can be determined by the addition of the alkylene oxides. If ethylene oxide and then propylene oxide are added alternately, blocks of these monomers are formed in the prepolymer as a function of the amounts added; this is also referred to as the block mode of operation. If both alkylene oxides are added simultaneously, the alkylene oxides react arbitrarily, which is also referred to as the mixed mode of operation. The mixed mode of operation is preferred. A person skilled in the art can control the structure of the polyol and the molar distribution of the monomers within a narrow range on the basis of the molecular weights of the alkylene oxides and control of the amounts added. In a preferred embodiment, exclusively ethylene oxide is added in a step 2 to the prepolymer from step 1 , so that the diol A has ethoxy groups at the ends.

The ring-opening polymerization is carried out with the aid of catalysts. Here, preference is given to basic catalysts such as alkali metal or alkaline earth metal hydroxides or alkali metal or alkaline earth metal alkoxides, preferably NaOH, KOH, CsOH or sodium methoxide and potassium methoxide. Other preferred catalysts are ones which comprise functional amino groups; preferred examples are N,N-dimethylethanolamine (DMEOA) or imidazole. A third group of preferred catalysts is carbenes, preferably N-heterocyclic carbenes.

The product obtained in step 2 is precipitated by means of a precipitant in step 3. Precipitants are usually proton donors; examples of preferred precipitants are carbonic acid (H2CO3), phosphoric acid (H3PO4). The polymer worked up in step 3 is filtered in a 4th step in order to remove the catalyst. Binders are used as filtration aids; preferred examples of binders are cellulose or silica gel. Diol B is prepared analogously, with exclusively butylene oxide being used in step 1 and step 2 being omitted.

A preferred diol A is the polyol which can be procured under the name Lupranol VP9243 from BASF Polyurethanes GmbH in October 2013.

Mixture of polyol

In one preferred embodiment the polyol is a polyol mixture of the diol A and diol B as outlined above with at least one further polyol, as indicated above. In a case of using a polyol mixture of a further polyol and diols A and B, the further polyol is used in an amount of less than 50 % by weight, preferably less than 35 % by weight, more preferably less than 15 % by weight, and most preferably less than 5 % by weight, based on the total weight of the polyol mixture.

In one preferred embodiment the polyol is a mixture of diol A and diol B. The further polyol in a preferred embodiment is a diol. In this case the polyol is also referred to as diol.

Chain extender

In preferred embodiments a chain extender is used in the synthesis of the polyurethane, preferably the thermoplastic polyurethane. The chain extender preferably is an aliphatic, araliphatic, aromatic and/or cycloaliphatic compound, preferably with a molecular weight of 0.05 x 10³ g/mol to 0.499 x 10³ g/mol, preferably with 2 groups reactive with isocyanate, which are also referred to as functional groups. The chain extender is either a single chain extender or a mixture of at least two chain extenders. The chain extender is preferably a difunctional compound, preferred examples being diamines or alkane diols having 2 to 10 carbon atoms in the alkylene radical, or a mixture thereof. In a preferred embodiment the chain extender (c) is selected from the group consisting of 1 ,2- ethylene glycol, 1 ,2-propanediol, 1 ,3-propanediol, 1 ,4-butanediol, 2,3-butanediol, 1 ,5-pentane- diol, 1 ,6-hexanediol, diethylene glycol, di-, tri-, tetra-, penta-, hexa-, hepta-, okta-, nona- and/or deca alkylene glycole, dipropylene glycol, 1 ,4-cyclohexanediol, 1 ,4-dimethanol cyclohexane, neopentylglycol and hydroquinone bis (beta-hydroxyethyl) ether (HQEE), or is a mixture thereof. Preferably the chain extender selected from the group consisting of 1 ,2-ethylene glycol, 1 ,3-pro- panediol, 1 ,4-butanediol, and 1 ,6-hexanediol, di-, tri-, tetra-, penta-, hexa-, hepta-, okta-, nona- and/or deca alkylene glycol, preferably respective oligo- and/or polypropylene glycol, or is a mixture thereof.

Particularly preferred chain extender is 1 ,3-propanediol, 1 ,4-butanediol or 1 ,6-hexanediol, or is a mixture thereof.

In one preferred embodiment the chain extender comprises, preferably is 1 ,6-hexandiol.

Catalyst

Catalysts (d) which, in particular, accelerate the reaction between the NCO groups of the isocyanates (a) and the hydroxyl groups of the polyol and the chain extenders, in a preferred embodiment is selected from the group consisting of tertiary amines and organic metal compound, or is a mixture thereof.

A preferred tertiary amine is selected from the group consisting of triethylamine, dimethylcyclohexylamine, N-methylmorpholine, N,N'-dimethyl-piperazine, 2-(dimethylaminoethoxy)ethanol, diazabicyclo[2.2. octane], or is a mixture thereof;

A preferred organic metal compound is selected from the group consisting of titanic ester, iron compound, tin compound, and bismuth salt, or is a mixture thereof. A preferred iron compound is iron(lll) acetylacetonate. A preferred tin compound is selected from the group consisting of tin diacetate, tin dioctoate, tin dilaurate and dialkyl tin salts of aliphatic carboxylic acids, preferably tin dioctoate, or is a mixture thereof. A preferred titanic ester is tetrabutyl orthotitanate. In preferred bismuth salts, the bismuth is present in the oxidation states 2 or 3, in particular 3, with preference being given to salts of carboxylic acids, preferably carboxylic acids having from 6 to 14 carbon atoms, particularly preferably from 8 to 12 carbon atoms. A very preferred bismuth salt is bismuth(lll) neodecanoate, bismuth 2-ethylhexanoate, or bismuth octanoate, or is a mixture thereof. The catalysts (d) is preferably used in an amount of from 0.0001 to 0.1 part by weight per 100 parts by weight of the compound reactive toward isocyanates, preferably polyol. Preference is given to using tin catalysts, in particular tin dioctoate.

A very preferred catalyst is SDO (tin (II) 2-ethylhexanoate), preferably used in quantities of 0.35- 0.4 parts per weight, referring to the composition.

Auxiliary

In preferred embodiments an auxiliary or additive (e) is added to the composition. Preferred examples include surface-active substances, fillers, flame retardants, nucleating agents, oxidation stabilizers, lubricating and demolding aids, dyes and pigments, if necessary stabilizers, preferably against hydrolysis, light, heat or discoloration, inorganic and/or organic fillers, reinforcing agents and/or plasticizers.

Stabilizers in the sense of this invention are additives which protect a plastic or a plastic composition against harmful environmental influences. Preferred examples are primary and secondary antioxidants, sterically hindered phenols, hindered amine light stabilizers, UV absorbers, hydrolysis inhibitors, quenchers, and flame retardants. Examples of commercial stabilizers are given in Plastics Additives Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), p.98-S136.

In a preferred embodiment, the UV absorber has a number average molecular weight greater than 0.3 x 10³ g/Mol, in particular greater than 0.39 x 10³ g/Mol. Furthermore, the preferred UV absorber has a molecular weight not exceeding 5 x 10³ g/Mol, particularly preferred not exceeding 2 x 10³ g/mol.

The UV absorber is preferably selected from the group consisting of cinnamates, oxanilides and benzotriazole, or is a mixture thereof, particularly suitable as UV absorbers is benzotriazole. Examples of particularly suitable UV-absorbers are Tinuvin® 213, Tinuvin® 234, Tinuvin® 312, Tinuvin® 571 , Tinuvin® 384 and Eversorb® 82.

Preferably the UV absorbers is added in quantities of 0.01 wt.% to 5 wt.% based on the total weight of the composition, preferably 0.1 wt.% to 2.0 wt.%, in particular 0.2 wt.% to 0.5 wt.%.

Often a UV stabilization based on an antioxidant and a UV absorber as described above is not sufficient to guarantee a good stability of the composition against the harmful influence of UV rays. In this case, in addition to the antioxidant and/or the UV absorber, or as single stabilizer, a hindered-amine light stabilizer (HALS) is be added to the composition. Examples of commercially available HALS stabilizers can be found in Plastics Additive Handbook, 5th edition, H. Zweifel, Hanser Publishers, Munich, 2001, pp. 123-136.

Particularly preferred hindered amine light stabilizers are bis-(1 ,2,2,6,6-penta-^,methylpiperidyl) sebacat (Tinuvin® 765, Ciba Spezialitatenchemie AG) and the condensation product of 1-hy- droxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid (Tinuvin® 622). In particular, the condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidines and succinic acid (Tinuvin® 622) is preferred, if the titanium content of the finished product is less than 150 ppm, preferably less than 50 ppm, in particular less than 10 ppm, based on the components used.

HALS compounds are preferably used in a concentration of from 0.01 wt.% to 5 wt.%, particularly preferably from 0.1 wt.% to 1 wt.%, in particular from 0.15 wt.% to 0.3 wt.%, based on the total weight of the composition.

A particularly preferred UV stabilization contains a mixture of a phenolic stabilizer, a benzotriazole and a HALS compound in the preferred amounts described above.

Further information on the above-mentioned auxiliaries and additives can be found in the technical literature, e.g. Plastics Additives Handbook, 5th edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001.

In a preferred embodiment the composition according to any of the precedent embodiments or one of their preferred embodiments the perchlorate is selected from the group consisting of ammonium perchlorate, calcium perchlorate, kalium perchlorate, magnesium perchlorate, sodium perchlorate, zinc perchlorate, or is a mixture thereof., most preferred the perchlorate comprises sodium perchlorate. With an amount of more than 50 weight % referring to the whole amount of perchlorate, more preferred more than 70 weight %, more preferred more than 90 weight%, more preferred more than 95 weight %, more preferred more than 99 weight %. Most preferred the perchlorate is sodium perchlorate.

In a preferred embodiment according to one of the precedent embodiments or one of its preferred embodiments the perchlorate is comprised in an amount of from 0.1% by weight to 25% by weight, preferably from 0.2 % by weight to 10 % by weight, more preferably from 0.3 % by weight to 7.5% by weight and particularly preferably from 0.5 % by weight to 4 % by weight, based on the thermoplastic polyurethane composition In another embodiment the composition comprises at least one further polymer beside the thermoplastic polyurethane. More preferred the polymer is selected from the group consisting of polyethylene, polypropylene, polystyrene, polyoxymethylene, ethylene-vinyl acetate, acryloni- trile-butadiene-styrene, polyvinyl chloride, and thermoplastic polyurethane. Preferably the recipe of the thermoplastic polyurethane differs from that of the composition. More preferred the polymer is selected from the group consisting of polyethylene, polypropylene and polystyrene, or is a mixture thereof.

In a preferred embodiment the polymer is comprised in the composition with 1% by weight and less than 50% by weight, preferably more than 5% by weight and less than 35% by weight, particularly preferably more than 15% by weight and less than 30% by weight.

Production Process

Another aspect of the invention is the production of the composition comprising a thermoplastic polyurethane according to any of the precedent embodiments, or one their preferred embodiments.

The composition comprising the thermoplastic polyurethane in an embodiment is produced discontinuously or continuously. A preferred process, is the reaction extruder process, the belt line process, the “one shot” process, preferably the "one-shot" process or the reaction extruder process, most preferably the reaction extruder-process.

These processes are used either by directly mixing the building components or alternatively by applying the prepolymer process.

Polyisocyanate prepolymers are obtainable by reacting above-described polyisocyanate in excess, at temperatures of 30 °C to 100 °C, preferably at 8 x10 °C, with the compound reactive isocyanate, preferably the polyol.

In the "one-shot" process, the building components diisocyanate and polyol, preferably polyol diol, and in a preferred embodiment also the chain extender, are mixed with each other. This is done either in succession or simultaneously, in preferred embodiment in the presence of the catalyst. In the extruder process, the building components diisocyanate and diol, in a preferred embodiment also the chain extender, and, in further preferred embodiments, also the catalyst are mixed. The mixing in the reaction extruding process is done preferably at temperatures between 100°C and 280°C, preferably between 140°C and 250°C. The thermoplastic polyurethane obtained, preferably is in the form of a granulate or a powder. Auxiliaries and additives may be added during the synthesis preferred or are added to the thermoplastic polyurethane. The latter is preferred especially, if the additive or auxiliary is not inert against isocyanate, the chain extender, the compound reactive with isocyanate, or the catalyst. The auxiliaries and/ or perchlorate in one embodiment are added during synthesis of the thermoplastic polyurethane. In another preferred embodiment the auxiliary and/or the perchlorate is added to the thermoplastic polyurethane after its synthesis, more preferably in an extruder.

A twin-screw extruder is preferred, as the twin-screw extruder operates with positive conveying and thus allows a more precise setting of the temperature and output quantity on the extruder. All components of the following production processes are described and preferred above.

In a preferred embodiment the thermoplastic polyurethane is prepared from an isocyanate a polyol comprising a diol A and a diol B and a chain extender, optionally with the aid of a catalysts and optionally further comprising additives and/or auxiliaries, wherein the diol A comprises ethoxy and propoxy groups and the diol B comprises butoxy groups.

In a preferred embodiment producing the composition as outlined and preferred above, the thermoplastic polyurethane is prepared in a step A and this thermoplastic polyurethane is mixed with the perchlorate in a step B.

In another preferred embodiment a blend as outlined above is prepared by producing the thermoplastic polyurethane in a step A and mixing this thermoplastic polyurethane with the perchlorate in a step B and then mixing the product from step A and B with a polymer as outlined and preferred above.

Form of the beads

In a preferred embodiment the composition comprising thermoplastic polyurethane according to one of the precedent embodiments or its preferred embodiments is in the form of a pellet or a powder. The pellet or powder in a preferred embodiment is a compact material.

Use for an article

Another aspect of the invention and preferred embodiment is the use of the composition according to one of precedent embodiments or its preferred embodiment for improving the electric conductivity in an article.

In other words, a preferred embodiment is the use of the composition as conductivity improver for a polymer.

In a preferred embodiment the composition of this invention is blended with a second composition comprising a polymer before forming the article. The composition as such is also referred to as master batch, The composition blended with another polymer as outlined above, is also referred to as blend.

The forming of these articles is preferably done by injection moulding, calendering, producing of films, powder sintering, or extrusion.

In yet another embodiment the composition of this invention is used for polymers from which expanded beads, preferably those comprising thermoplastic polyurethane, are produced.

These foamed beads and also articles produced therefrom may be used in various applications (see e.g. WO 94/20568, WO 2007/082838 A1 , WO2017030835, WO 2013/153190 A1 , WO2010010010), EP 21168694.4), herein incorporated by reference. In preferred embodiments articles, as outlined and preferred herein, are produced from these expanded beads

Yet another aspect of the invention is the article produced with a composition according to one of the embodiments as outlined above or its preferred embodiments.

Preferably these article is selected from the group consisting of cable, cases, cell-phone, coating, covers, damping element, bellows, foil, fiber, film, moulded body, roofing or flooring for buildings or vehicles, non woven fabric, gasket, packaging material, roll, shoe sole, middle sole of a shoe, hose, cable, cable connector, cable sheathing, pillow, laminate, phone, profile, strap, saddle, foam, by additional foaming of the preparation, plug connection, television, trailing cable, solar module, lining in automobiles, wiper blade, elevator load bearing members, roping arrangements, drive belts for machines, preferably passenger conveyer, handrails for passenger conveyers modifier for thermoplastic materials, which means substance that influences the properties of another material. Each of these articles itself is a preferred embodiment, also referred to as an application.

More preferably the product is selected from covers, packaging material, cases, film, phone, cell phones, television, or cable, more preferably for an electronic device.

In a very preferred embodiment, the packaging material is a stretchable film, more preferably as outlined in PCT/EP2021/059230.

In another preferred embodiment the cover is for electronic device, preferably as outlined in WO 2018/015504 Examples

Example 1 - Materials used

HDPE: Lupolen 4261 AG, a typical high molecular weight, high-density polyethylene was used. Lupolen 4161 AG exhibits a density (determined according to DIN EN ISO 1183-1 :2019, A) of 0.945 g em^-3, an MFR (determined according to DIN EN ISO 1133-1 :2011) at 190 °C and 21.6 kg of 6.0 g/(10 min), and a Vicat temperature (determined according to DIN EN ISO 306:2013, A) of 126 °C.

Antistatic TPU composition 1 : The composition (=100 wt%) comprising 19.9 wt% of hexamethylene diisocyanate (HDI), 10.3 wt% of 1 ,6-hexanediol, 13.1 wt% of a polytetramethylene glycol (PTMG) having a number average molecular weight of 2.0x10³ g/mol, and 52.4 wt% of a bifunctional polymer diol with ethoxy and propoxy groups with average molecular weight between 1 .5 10³ g/mol and 3.0- 10³ g/mol are converted into the antistatic thermoplastic polyurethane (TPU) composition 1 in a reaction extruder. Also incorporated are 3 wt% of a 1-ethyl-3-methyl-1-imidaz- olium ethylsulfate, (EMIN ETOSO3), 1.3 wt% of an additive mixture comprising antioxidant (AO, hindered phenol derived from pentaerythritol and di-tert-butyl hydroxyphenylpropanamide), hindered amine light stabilizer (HALS, condensation product of i-hydroxyethyl-2,2,6,6-tetramethyl-4- hydroxypiperidine and succinic acid), UV filter (2-(2H-benzotriazol-2-yl)-4,6-bis(1 -methyl-1-phe- nylethyl)phenol), chain regulator (octanol), and lubricant (distearamide).

TPU matrix: The composition (=100 wt%) comprising 21.3 wt% of hexamethylene diisocyanate (HDI), 10.5 wt% of 1 ,6-hexanediol, 13.3 wt% of polytetramethylene glycol (PTMG) having a number average molecular weight (M_w) of 1.0-10³ g/mol, and 53.2 wt% of a bifunctional polymer diol with ethoxy and propoxy groups with average molecular weight between 1.5- 10³ g/mol and 3.0- 10³ g/mol is converted into a thermoplastic polyurethane (TPU) in a reaction extruder. In the composition are also incorporated 1.75 wt% of an additive mixture comprising antioxidant (AO, hindered phenol derived from pentaerythritol and di-tert-butyl hydroxyphenylpropanamide), hindered amine light stabilizer (HALS, condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypi- peridine and succinic acid), UV absorber (2-propenoic acid, 2-cyano-3,3-diphenyl-, 2,2-bis[[(2- cyano-1-oxo-3,3-diphenyl-2-propenyl)oxy]methyl]-1 ,3-propanediyl ester) and chain regulator (octanol). Antistatic TPU composition 2: The composition (=100 wt%) comprising 91 .7 wt% of the TPU matrix and 8.3 wt% of antistatic agent in polymer matrix (20-25 wt% sodium perchlorate) were converted into an antistatic TPU composition in an extruder.

Example 2 - Antistatic TPU-polymer blends

To manufacture an antistatic TPU polymer blend, 82 wt% of the base polymer (e.g. Lupolen 4261 AG) and 18 wt% of the antistatic TPU composition 1 or 2 were compounded in an extruder and formed to test plates of 10 cm x 10 cm x 2 mm by injection molding.

Tab. 1. Formulations of the polymer compositions.

Example 3 - Aging

The aging of the test plates (10 cm x 10 cm x 2 mm ) prepared via injection molding was conducted according to ISO 4892-2A Cycle 1 (Atlas).

Example 4 - Measurements

The surface resistivity of the test plates of the polymer compositions according to Example 2 and aged according to Example 3 were measured according to DIN EN 62631-3-2:2018-09 at 23 °C and 72% rel. humidity. According to DIN EN 62631-3-2:2018-09 the surface resistivities were converted into the specific surface resistivities according to the following formulas: (a) Bar electrode:

With: o_Bar ... Specific surface resistivity R_Bar ... Measured resistance

I ... length of the bar electrodes g ... distance between the bar electrodes

(b) Ring electrode:

With: o_Ring - Specific surface resistivity

R_Ring ■■■ Measured resistance d ... Outer diameter of the ring electrode d₂ ... Inner diameter of the ring electrode

Tab. 2. Specific surface resistivities of the prepared polymer compositions before and after aging.

Claims

210647 WO 2023/025638 PCT/EP2022/072989 16 Claims: Claims:

1 . A composition comprising a thermoplastic polyurethane, where the thermoplastic polyurethane is prepared from a) an isocyanate, b) a polyol comprising a diol A comprising ethoxy and propoxy groups and a diol B comprising butoxy groups, and c) a chain extender, optionally with the aid of a catalysts, and optionally further comprising additives and/or auxiliaries, wherein a perchlorate is comprised in the composition.

2. The composition according to claim 1 , wherein the perchlorate is selected from the group consisting of ammonium perchlorate, calcium perchlorate, kalium perchlorate, lithium perchlorate, magnesium perchlorate, sodium perchlorate, zinc perchlorate, or is a mixture thereof.

3. The composition according to claim 1 , wherein the perchlorate is sodium perchlorate.

4. The composition according to any of the precedent claims, wherein the molar % of the ethoxy and propoxy groups and butoxy groups is in each case at least 5 mol%, preferably at least 10 mol%, referred to the total diol.

5. The composition according to either of the preceding claims, wherein the proportion of the ethoxy groups in the diol A is at least 25 mol%, more preferably at least 40 mol% and particularly preferably at least 50 mol%, based on the total diol A.

6. The composition according to any of the preceding claims, wherein the diol B is polybutylene diol.

7. The composition according to any of the preceding claims, wherein the diol A is a block copolymer having a block and two ends and the block comprises ethoxy and propoxy groups and the two ends of the block copolymer comprise ethoxy groups only.

8. The composition according to the preceding claim, wherein the proportion of the ethoxy groups in the two ends of the block copolymer is more than 5 mol%, preferably at least 10 mol% and particularly preferably at least 15 mol%, based on the total block copolymer.

9. The composition according to any of the preceding claims, wherein the perchlorate is comprised in an amount of from 0.1% by weight to 25% by weight, preferably from 1 % by weight to 10% by weight, more preferably from 1.5% by weight to 7.5% by weight and particularly preferably from 2% by weight to 5% by weight, based on the thermoplastic polyurethane composition.

10. The composition according to any of the preceding claims, wherein the diisocyanate is an aliphatic diisocyanate.

11. A blend comprising a composition according to any of the preceding claims and a polymer.

12. The blend according to the preceding claim, wherein the polymer is selected from the group consisting of polyethylene, polypropylene, polystyrene, polyoxymethylene, ethylene-vinyl acetate, acrylonitrile-butadiene-styrene, polyvinyl chloride, thermoplastic polyurethane, or is a mixture thereof.

13. A process for producing a composition according to any of claims 1 to 10, wherein the thermoplastic polyurethane is prepared in a step A and this thermoplastic polyurethane is mixed with the perchlorate in a step B.

14. A process for producing a blend according to any of claims 11 to 13, wherein the thermoplastic polyurethane is prepared in a step A and this thermoplastic polyurethane is mixed with the perchlorate in a step B and the product from step A and B is mixed with a polymer.

15. The use of a composition according to any of claims 1 to 10 as conductivity improver for a polymer.