EP3008129A1

EP3008129A1 - Heatable molded articles made from electrically conductive thermoplastic polyurethane

Info

Publication number: EP3008129A1
Application number: EP14729340.1A
Authority: EP
Inventors: Zeljko Tomovic; Frank Prissok; Stefan Arenz
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2013-06-14
Filing date: 2014-06-11
Publication date: 2016-04-20
Also published as: US20160135253A1; JP2016523296A; BR112015031145A2; KR20160021239A; JP2019167546A; CN105722915A; WO2014198752A1; CN105722915B

Abstract

The present invention relates to the use of a composition (Z1), at least containing an elastomer (E1) and a conductivity-imparting additive (A1) based at least 90% on carbon, for producing an electrically heatable molded article for the automotive field, wherein the composition (Z1) has a Shore A hardness, determined according to DIN 53505, in the range from 30 to 95, an electrical specific transition resistance, determined according to ISO 3915, of less than 1x 10² ohm x cm and greater than 0.01 ohm x cm, and an elongation at tear, determined according to DIN 53504, of greater than 300%. The present invention further relates to a method for producing an electrically heatable molded article for the automotive field comprising a composition (Z1), and to electrically heatable molded articles for the automotive field comprising a composition (Z1).

Description

The present invention relates to the use of a composition (Z1) comprising at least one elastomer (E1) and an at least 90% carbon-based conductivity-promoting additive (A1) for producing an electrically heatable molding for the automotive sector wherein the composition (Z1) has a Shore hardness a, determined to DIN 53505, in the range of 30 to 95, an electrical volume resistivity, determined according to ISO 3915, of less than 1 × 10 ² ohm x cm, and greater than 0.01 Ohm x cm , and an elongation at break, determined according to DIN 53504, of greater than 300%. Furthermore, the present invention relates to a method for producing an electrically heatable molded article for the automotive sector comprising a composition (Z1) and electrically heatable moldings for the automotive sector comprising a composition (Z1). Preferred elastomers (E1) are polyurethanes, in particular thermoplastic polyurethanes.

The production of thermoplastic polyurethanes, which are also abbreviated below as TPU, is well known. TPUs are semi-crystalline materials and belong to the class of thermoplastic elastomers. Characteristic of polyurethane elastomers is the segmented structure of the macromolecules. Due to the different cohesive energy densities of these segments, in the ideal case a phase separation into crystalline "hard" and amorphous "soft" regions takes place. The resulting two-phase structure determines the property profile of TPU. Thermoplastic polyurethanes are plastics with a wide range of applications. For example, TPUs are found in the automotive industry, e.g. in instrument panel hides, in foils, in cable sheathing, in the leisure industry, as heel stains, as a functional and design element in sports shoes, as a soft component in hard-soft combinations and in many other applications.

In order to improve the property profile of TPU, it is known from the literature to introduce crosslinking into the TPU which leads to increased strength, improved heat resistance, reduced tensile and compression set, improved resistance to all types of media, resilience and creep behavior become.

The use of auxiliaries and additives for adjusting certain material properties is also known.

WO 2008/116801 A1 relates to a process for the preparation of crosslinked polyurethanes having a Shore A hardness between 55 and 85 by reacting thermoplastic polyurethanes with compounds containing isocyanate groups, wherein the reaction is carried out in the presence of a prepolymer containing the reaction product of isocyanates with Represents isocyanate-reactive compounds having a molecular weight between 500 g / mol and 10,000 g / mol. Furthermore, the invention relates to polyisocyanate polyaddition products, in particular fibers, hoses, cable sheaths, profiles, moldings and films, which are obtainable by the process. WO 2010/149636 A2 discloses polyurethanes based on a thermoplastic polyurethane and an isocyanate added to the thermoplastic polyurethane, preferably under reaction. In this case, the isocyanate is preferably an isocyanate concentrate having a functionality greater than 2. According to WO 2010/149636 A2, the thermoplastic polyurethane has a hard phase content of 0% to 5%, in particular 2% to 4%, and the isocyanate is at least 2 % By weight to 20 wt .-%, particularly preferably 3 wt .-% to 15 wt .-%, in particular at least 3 wt .-% to 10 wt .-%, based on the polyurethane added. WO 2006/134138 A1 relates to a thermoplastic polyurethane comprising between 20% by weight and 70% by weight of isocyanate dissolved in the thermoplastic polyurethane, based on the total weight of the thermoplastic polyurethane containing the isocyanates, and to processes for preparing these thermoplastic polyurethanes containing isocyanate , According to WO 2006/134138 A1, thermoplastic polyurethane is preferably melted and then the isocyanate is preferably incorporated homogeneously into the melt. In addition, WO 2006/134138 A1 relates to processes for the preparation of polyurethanes.

DE 10 2012 203 994 A1 relates to antistatic or electrically conductive polyurethanes containing carbon nanotubes and ionic liquids. Furthermore, DE 10 1012 203 994 A1 relates to a process for the preparation of these polyurethanes and their use for the preparation of e.g. Rollers, films, floor coverings, coatings, sheets, moldings, profiles, rollers, wheels, hoses, linings in automobiles, gaskets, straps, cable sheathing, fibers, cable plugs, bellows, damping elements, electrically heatable moldings, and shoe soles. WO 2005/082988 A1 also discloses a thermoplastic polyurethane containing carbon nanotubes.

EP 0 831 117 A1 relates to the use of thermoplastic molding compositions based on 30 to 94 wt .-% of a Polyoxymethylenhomo- or copolymerizate, and 6 to 10 wt .-% carbon black with a pore volume (DBP adsorption) according to DIN 53 601 of at least 350th ml / 100g and optionally other components for the production of electrically heated moldings. Furthermore, EP 0 831 117 A1 relates to the electrically heatable molded parts obtainable in this case.

EP 0 571 868 A1 relates to the use of an at least single-layered, electrically conductive thermoplastic polyurethane (TPU) film as a flexible insert for containers for storing combustible liquids containing at least TPU as the basic raw material, carbon black having a BET surface area of greater than or equal to 600 m ² / g and optionally contains the additives known for TPU and film production.

Especially in the automotive sector, many components are needed that are sufficiently soft to ensure full functionality. This property must be present both at outdoor temperatures above freezing and at significantly lower temperatures. By using additives to adjust certain material properties Shanks have elastomers, especially thermoplastic polyurethanes, often not the desired suppleness.

In particular, wiper blades for automobiles, which are usually made of crosslinked rubber or partially crosslinked thermoplastic polyurethanes, require u.a. sufficient softness and suppleness to thoroughly remove the water film from the windshield.

At low outside temperatures in winter, the wiper blades stiffen, their wiping performance decreases. In addition, at temperatures below 0 ° C water freezes on and on the wiper blades, which significantly wipes the wiping performance or makes wiping impossible. Even if the pane itself is heated, ice forms on the outer wipers.

Starting from the prior art, the object of the present invention was therefore to provide moldings which have sufficient flexibility and good strength for use in the automotive sector in different temperature ranges. In particular, the shaped bodies should also have good resilience. Another object of the present invention is to provide moldings which have the desired properties even at low outside temperatures.

According to the invention, this object is achieved by the use of a composition (Z1) comprising at least one elastomer (E1) and an at least 90% carbon-based conductivity-promoting additive (A1) for producing an electrically heatable shaped body for the automobile sector, the composition (Z1) has the following properties:

a Shore hardness A, determined to DIN 53505, in the range of 30 to 95, an electrical volume resistivity, determined according to ISO 3915, of less than 1 × 10 ² ohm x cm, and greater than 0.01 Ohm x cm, and

an elongation at break, determined according to DIN 53504, of greater than 300%.

It has surprisingly been found that the use according to the invention of a composition (Z1) leads to particularly advantageous shaped articles. The moldings have a high elongation at break and are sufficiently flexible for a wide variety of applications. In addition, the resulting moldings are electrically conductive. Due to the special electrical volume resistivity see the moldings are electrically heated, so that even at lower ambient temperatures, the temperature of the molding can be adjusted per se to prevent deterioration of certain properties, such as flexibility or suppleness. The moldings obtained according to the invention are preferably heatable to a temperature in the range from 0 ° C. to 100 ° C., more preferably to a temperature in the range from 10 ° C. to 60 ° C. and particularly preferably in the range from 15 ° C. to 50 ° C., more preferably in the range of 20 ° C to 40 ° C. In this case, it is essential according to the invention that heating of the molded part in relation to the respective outer window takes place. For example, if the molded part is in an outside temperature of -20 ° C., heating according to the invention can also take place at 0 ° C.

As elastomer (E1), in the context of the present invention it is possible in principle to use any suitable elastomer which has a suitable property profile. suitable

Elastomers (E1) are, for example, crosslinked elastomers, for example rubber, polyurethanes or else blends of various materials, for example blends of polyurethanes and at least one further elastomer or else blends of various polyurethanes, and also polyether block copolymers, polyester block copolymers and polyether amides. Particularly suitable in the context of the present invention as the elastomer (E1) are polyurethanes, more preferably thermoplastic polyurethanes.

Accordingly, the present invention also relates to the use of a composition (Z1) as described above, wherein the elastomer (E1) is a thermoplastic polyurethane.

Processes for the preparation of elastomers (E1), in particular of thermoplastic polyurethanes, are well known. The polyurethanes are preferred by reacting (a) isocyanates with (b) isocyanate-reactive compounds having a number average molecular weight of 0.5 kg / mol to 12 kg / mol and preferably (c) chain extender mittein having a number average molecular weight of 0 , 05 kg / mol to 0.499 kg / mol, optionally prepared in the presence of (d) catalysts and / or (e) conventional excipients.

In the following, exemplary preferred starting components and processes for the preparation of preferred polyurethanes are shown. The components of (a) isocyanates which are preferred in the preparation of these polyurethanes, (b) isocyanate-reactive compounds, (c) chain extenders and optionally (d) catalysts and / or (e) conventional auxiliaries will be described below. The isocyanates (a), the isocyanate-reactive compounds (b) and, if used, the chain extenders (c) are also addressed as synthesis components.

As organic isocyanates (a) it is possible to use generally known isocyanates, preferred are aromatic, aliphatic, cycloaliphatic and / or aliphatic isocyanates, more preferably diisocyanates, preferably 2,2'-, 2,4'- and / or 4,4'- Diphenylmethane diisocyanate (MDI), 1,5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-tolylene diisocyanate (TDI), 3,3'-dimethyl-diphenyl diisocyanate, 1, 2-diphenyl-ethane diisocyanate and / or phenylene diisocyanate, tri-, tetra-, penta-, hexa-, hepta- and / or octamethylene diisocyanate, 2-methylpentamethylene diisocyanate-1, 5,2-ethyl-butylene-diisocyanate-1,4, pentamethylene diisocyanate-1, 5, butylene diisocyanate 1, 4,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, IPDI), 1, 4 and / or 1, 3-bis (isocyanatomethyl) cyclohexane (HXDI), 1,4-cyclohexane diisocyanate, 1-methyl-2,4- and / or 2,6-cyclohexane diisocyanate and / or 4,4'-, 2,4'- and 2 , 2'-Dicyclohexylmethane diisocyanate (H12MDI). Further preferred 2,2'-, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), 1, 5-naphthylene diisocyanate (NDI), 2,4- and / or 2,6-Toluylendiiso- cyanate (TDI), hexamethylene diisocyanate (HDI), 4,4'-, 2,4'- and 2,2'-dicyclohexyl- methane diisocyanate (H12MDI) and / or 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane IPDI, particularly preferably 4,4'-MDI. In a preferred embodiment, only one isocyanate is used to make a polyurethane, in another preferred embodiment, at least two different isocyanates are used to make the polyurethane.

As isocyanate-reactive compounds (b) it is possible to use generally known isocyanate-reactive compounds; preference is given to polyesterols, polyethers and / or polycarbonatediols which are also grouped under the term "polyols" with number average molecular weights of 0.5 kg / mol to 12 kg / mol, preferably 0.6 kg / mol to 6 kg / mol, in particular 0.8 kg / mol to 4 kg / mol, and preferably an average functionality of 1, 8 to 2.3, preferably 1 , 9 to 2.2, in particular 2. The average functionality here indicates the number of groups in a mixture that are present on average per molecule and react with the isocyanate group. These polyols form the soft phase component.

As the chain extender (c), generally known aliphatic, araliphatic, aromatic and / or cycloaliphatic compounds, preferably having a number average molecular weight of from 0.05 kg / mol to 0.499 kg / mol, preferably 2-functional compounds, i. such molecules with two isocyanate-reactive groups can be used. Preference is given to diamines and / or alkanediols having 2 to 10 C atoms in the alkylene radical, in particular butanediol-1, 4, 1,6-hexanediol, 1,3-propanediol, 3-ethylene glycol 1, 2 and / or di-, tri-, Tetra, penta, hexa, hepta, octa, nona and / or Dekaalkylenglykole having up to 8 carbon atoms, preferably corresponding oligo- and / or polypropylene glycols, wherein mixtures of the chain extenders are used in a preferred embodiment. The chain extenders (c) form the hard phase component with the isocyanates (a).

Suitable catalysts (d) which in particular accelerate the reaction between the NCO groups of the isocyanates (a), preferably the diisocyanates and the hydroxyl groups of the synthesis components (b) and (c), are known and customary in the prior art. tertiary amines, preference is given to triethylamine, dimethylcyclohexylamine, N-

Methylmorpholine, N1 '- dimethylpiperazine, 2- (dimethylaminoethoxy) ethanol, diazabicyclo (2,2,2) octane and the like, and in particular organic metal compounds such as titanic acid esters, iron compounds, preferably iron (MI) - acetylacetonate, tin compounds, preferably Tin diacetate, tin dioctoate, tin dilaurate or the tin dialkyl salts, aliphatic carboxylic acids, preferably dibutyltin diacetate, dibutyltin dilaurate or the like. The catalysts are usually used in amounts of 0.00001 to 0.1 parts by weight per 100 parts by weight of polyhydroxyl compound (b).

In addition to catalysts (d), customary auxiliaries (e) are also added to structural components (a) to (c) in preferred embodiments. Examples include surfactants, flame retardants, nucleating agents, oxidation stabilizers, lubricants and mold release agents, dyes and pigments, stabilizers, eg. As against hydrolysis, light, heat or discoloration, inorganic and / or organic fillers, reinforcing agents and plasticizers.

As hydrolysis protective agents it is preferred to use oligomeric and / or polymeric aliphatic or aromatic carbodiimides. In order to stabilize a polyurethane against aging, stabilizers are preferably added to the polyurethane. Stabilizers in the context of the present invention are additives which protect a plastic or a plastic mixture against harmful environmental influences. Examples include primary and secondary antioxidants, hindered amine light stabilizers, UV absorbers, antihydrolysis agents, quenchers and flame retardants. Examples of commercial hydrolysis stabilizers and stabilizers can be found, for example, in the Plastics Additive Handbook, 5th Edition, H. Zweifel, ed., Hanser Publishers, Munich, 2001 ([1]), p. 98 - page 136.

If the TPU according to the invention is exposed to thermo-oxidative damage during its application, antioxidants can be added. Preferably, phenolic antioxidants are used. Examples of phenolic antioxidants are given in Plastics Additive Handbook, 5th edition, H. Zweifel, ed, Hanser Publishers, Munich, 2001, pp. 98-107 and pp. 116-122. Preferred are phenolic antioxidants whose molecular weight is greater than 700 g / mol. An example of a preferred phenolic antioxidant is pentaerythrityl tetrakis (3- (3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl) propionate (Irganox® 1010). The phenolic antioxidants are generally used in concentrations between 0.1 and 5 wt .-%, preferably between 0.1 and 2 wt .-%, in particular between 0.5 and 1, 5 wt .-%, each based on the Total weight of the TPU. Preferably, the TPUs are additionally stabilized with a UV absorber. UV absorbers are molecules that absorb energy-rich UV light and dissipate the energy. Common UV absorbers which are used in the art include, for. To the group of cinnamic acid esters, the diphenylcyanoacrylates, the formamidines, the benzylidenemalonates, the diarylbutadienes, triazines and the benzotriazoles. Examples of commercial UV absorbers can be found in Plastics Additive Handbook, 5th edition, H. Zweifel, ed, Hanser Publishers, Munich, 2001, page 116-122. In a preferred embodiment, the UV absorbers have a number average molecular weight of greater than 300 g / mol, in particular greater than 390 g / mol. Furthermore, the UV absorbers preferably used should have a molecular weight of not greater than 5000 g / mol, particularly preferably not greater than 2000 g / mol. Particularly suitable as a UV absorber is the group of benzotriazoles. Examples of particularly suitable benzotriazoles are Tinuvin® 213, Tinuvin® 328, Tinuvin® 571, and Tinuvin® 384 and the Eversorb®82. The UV absorbers are preferably added in amounts of between 0.01 and 5% by weight, based on the total mass TPU, more preferably between 0.1 and 2.0% by weight, in particular between 0.2 and 0.5 Wt .-%, each based on the total weight of the TPU. Often a UV stabilization based on an antioxidant and a UV absorber described above is still not sufficient to ensure good stability of the TPU according to the invention against the harmful influence of UV rays. In this case, to the component (e) preferably in addition to the antioxidant and the UV absorber, nor a Hindered Amine Light Stabilizer (HALS) may be added to the TPU according to the invention. The activity of HALS compounds rely on their ability to form nitroxyl radicals, which interfere with the mechanism of oxidation of polymers. HALS are considered to be highly efficient UV stabilizers for most polymers. HALS compounds are well known and commercially available. Examples of commercially available HALS stabilizers can be found in Plastics Additive Handbook, 5th edition, H. Zweifel, Hanser Publishers, Munich, 2001, pp. 123-136. Hindered Amine Light Stabilizers are preferably used as Hindered Amine Light Stabilizers where the number average molecular weight is greater than 500 g / mol. Furthermore, the molecular weight of the preferred HALS compounds should preferably not be greater than 10,000 g / mol, more preferably not greater than 5,000 g / mol. Particularly preferred hindered amine light stabilizers are bis (1, 2,2,6,6-pentamethylpiperidyl) sebacate (Tinuvin® 765, Ciba Spezialitätenchemie AG) and the condensation product of 1-hydroxyethyl-2,2,6,6- tetramethyl-4-hydroxypiperidine and succinic acid (Tinuvin® 622). Particularly preferred is the condensation product of 1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic acid (Tinuvin® 622) when the titanium content of the product is <150 ppm, preferably <50 ppm, more preferably <10 ppm , HALS compounds are preferably used in a concentration between 0.01 and 5 wt .-%, more preferably between 0.1 and 1 wt .-%, in particular between 0.15 and 0.3 wt .-%, each based on the Total weight of the TPU. A particularly preferred UV stabilization comprises a mixture of a phenolic stabilizer, a benzotriazole and a HALS compound in the preferred amounts described above.

As the plasticizer, all plasticizers known for use in TPU can be used. These include, for example, compounds containing at least one phenolic group. Such compounds are described in EP 1 529 814 A2. Further, for example, it is also possible to use polyesters having a molecular weight of about 500 to 1500 g / mol based on dicarboxylic acids, benzoic acid and at least one di- or triol, preferably one diol. The diacid component used is preferably succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, decanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid and / or terephthalic acid, and the diol used is preferably ethane-1,2-diol, diethylene glycol, propane-1,2-diene. diol, propane-1, 3-diol, dipropylene glycol, butane-1, 4-diol, pentane-1, 5-diol and / or hexane-1, 6-diol used. The ratio of dicarboxylic acid to benzoic acid is preferably 1:10 to 10: 1. Such plasticizers are described in more detail, for example, in EP 1 556 433 A1. Further details of the above-mentioned aids and additives are given in the literature, z. B. from Plastics Additive Handbook, 5th edition, H. Zweifel, ed, Hanser Publishers, Munich, 2001. All molecular weights mentioned in this document are number-average molecular weights and have, unless stated otherwise, the unit [kg / mol]. To adjust the hardness of a polyurethane, the constituent components (b) and (c) can be varied in relatively wide molar ratios. Molar ratios of component (b) to total chain extenders (c) to be used have proven to be from 10: 0 to 1: 0.35, the hardness of the polyurethane increasing with increasing content of (c). The preparation of the TPU can be carried out continuously, preferably with reaction extruders or the strip process according to one-shot or the prepolymer process, or discontinuously by the known processes. Preference is likewise given to the preparation via the prepolymer process. In these processes, the components (a), (b) and, if appropriate, (c), (d) and / or (e) which are being reacted can be mixed together successively or simultaneously, where the reaction starts immediately.

In the extruder process, the synthesis components (a), (b) and optionally (c), as well as the components (d) and / or (e) are introduced individually or as a mixture in the extruder, and preferably at temperatures of 100 ° C to 280 ° C, more preferably at 140 ° C to 250 ° C reacted. The resulting TPU is extruded, cooled and granulated.

In a particularly preferred embodiment, the thermoplastic polyurethane is based on an MDI as polyisocyanate and a polyesterol and / or polyetherol, in particular a polyester of adipic acid with butanediol and / or ethylene glycol and / or methylpropanediol or a polyether based on polytetrahydrofuran.

According to a further embodiment, the present invention also relates to the use of a composition (Z1) as described above, wherein the elastomer (E1) is a thermoplastic polyurethane based on at least one isocyanate, at least one polyol component having a molecular weight greater than 500 g / mol and at least one second polyol component having a molecular weight of less than 499 g / mol. Such polyurethanes are known in principle and have particularly good flexibility and elongation at break. Polyurethanes which are preferably used according to the invention are disclosed, for example, in WO 2010/149636 A2.

In a particularly preferred embodiment, the thermoplastic polyurethane has an index of from 980 to 1200. The index is defined by the molar ratio of the isocyanate groups of component (a) used overall in the reaction to the isocyanate-reactive groups, ie the active hydrogens, of the components (b) and optionally chain extender (c). If necessary, this means that the chain extender is always taken into account when it is added. With a figure of 1000, an isocyanate group of component (a) has an active hydrogen atom, ie, an isocyanate-reactive function, of components (b) and (c). For ratios above 1000 are more isocyanate groups than groups with active hydrogen atoms, eg. As OH groups, before. The composition (Z1) used according to the invention comprises at least one at least 90% carbon-based conductivity-promoting additive (A1). Basically, at least 90% of the carbon-based conductivity-promoting additive (A1) comprises at least 90% of the carbon-based conductive agent known to the person skilled in the art. suitable additives. According to the invention, the at least 90% carbon-based conductivity-promoting additive (A1) is preferably selected from the group consisting of carbon nanotubes, graphene and conductivity black or mixtures thereof. Preference is given to using carbon nanotubes or graphene, particularly preferably carbon nanotubes.

According to a further embodiment, the present invention also relates to the use of a composition (Z1) as described above, wherein the at least 90% carbon-based conductivity-conferring additive (A1) is selected from the group consisting of carbon nanotubes, graphene and conductivity carbon black and mixtures thereof.

According to a preferred embodiment, the present invention also relates to the use of a composition (Z1) as described above, wherein the at least 90% carbon-based conductivity-conferring additive (A1) is selected from the group consisting of carbon nanotubes and graphene and mixtures thereof. With particular preference, the composition (Z1) in the context of the present invention contains no further carbon-based conductivity-promoting additives in addition to carbon nanotubes and graphene. According to the invention, the conductivity-promoting additive (A1) is distributed as finely as possible in the composition. In this case, according to the invention, the amount of conductivity-promoting additive used can vary. Preferably, the additive is used in an amount of 0.1 to 30 wt .-% based on the total weight of the mixture. Depending on the type of conductivity-promoting additive (A1), the preferred amount used may vary.

According to a further embodiment, the present invention also relates to the use of a composition (Z1) as described above, wherein carbon nanotubes are used as the at least 90% carbon-based conductivity-promoting additive (A1).

If carbon nanotubes are used as the conductivity-promoting additive, they are preferably present as finely divided as possible. Carbon nanotubes, also referred to as carbon nanotubes or CNTs, are understood in the prior art to be mainly cylindrical carbon tubes with a diameter of between 3 and 100 nm and a length which is a multiple of the diameter. These tubes consist of one or more layers of ordered carbon atoms and have a different nucleus in morphology. These carbon nanotubes are also referred to as "carbon fibrils" or "hollow carbon fibers", for example. Carbon nanotubes have long been known in the literature. Typical structures of these carbon nanotubes are those of the cylinder type. In the case of the cylindrical structures, a distinction is made between the single-walled carbon nanotubes and the multi-walled cylindrical carbon nanotubes (Multi Wall Carbon Nano Tubes). Common methods for their preparation are for. For example, arc discharge, laser ablation, chemical vapor deposition (CVD), and chemical vapor deposition (CCVD). Also, the formation of carbon tubes in the arc process is known per se, wherein the resulting carbon nanotubes consist of two or more graphite layers and rolled up into a seamlessly closed cylinder and are nested. Depending on the roll-up vector, chiral and achiral arrangements of the carbon atoms relative to the longitudinal axis of the carbon fiber are possible. In this case, structures are possible in which a single contiguous graphite layer (so-called "scroll type") or interrupted graphite layers (so-called "onion type") are the basis for the structure of the nanotube.

Carbon nanotubes according to the invention are all single-walled or multi-walled carbon nanotubes of the cylinder type, scroll type or onion-like structure. Preference is given to using multi-walled carbon nanotubes of the cylinder type, scroll type or mixtures thereof.

Carbon nanotubes having a length to outside diameter ratio greater than 5, preferably greater than 10, are particularly preferably used.

The carbon nanotubes to be used, which may be present as agglomerates, in the non-agglomerated form preferably have an average outside diameter of 1 to 50 nm, preferably 2 to 30 nm, particularly preferably 3 to 20 nm and in particular 4 to 15 nm.

In addition to the carbon nanotubes of the scroll type with only one continuous or interrupted graphite layer, there are also carbon nanotube structures that consist of several graphite layers, which are combined into a stack and rolled up (multiscroll type). This carbon nanotube structure is similar to the simple-scroll carbon nanotubes in comparison to the structure of multi-walled cylindrical monocarbon nanotubes (cylindrical MWNT) to the structure of single-walled cylindrical carbon nanotubes (cylindrical SWNT).

Suitable methods for producing carbon nanotubes are known in principle from the prior art. A particularly preferred process for producing carbon nanotubes is known from WO 2006/050903 A2, EP 1401763, EP 1594802, EP 1827680 and WO 2007/0033438.

Particularly preferred multi-walled carbon nanotubes are used. A preferred example of such multi-walled carbon nanotubes is Nanocyl® 7000 from Nanocyl SA, Belgium. The content of carbon nanotubes in the composition (Z1) used in the present invention is preferably in the range of 0.1 to 20% by weight, more preferably 0.5 to 15% by weight, still more preferably 1 to 10% by weight. -%, particularly preferably from 1 to 7 wt .-% and in particular from 2 to 7 wt .-%, based on the total weight of the composition (Z1).

According to a further embodiment, the composition (Z1) in the context of the present invention contains no further carbon-based conductivity-conferring additives in addition to carbon nanotubes.

Also, the composition (Z1) used in the present invention may contain conductivity carbon black as an at least 90% carbon-based conductivity-imparting additive (A1). Carbon black is an amorphous form of carbon that has a high surface area to volume ratio. Soot is produced by incomplete combustion of heavy oil products such as FCC tar, coal tar, ethylene cracking tar and, to a lesser extent, vegetable oil. Any conventional form of carbon black can be used in the present invention. For example, commercially available products such as Ketjenblack® EC-600JD from AkzoNobel or Printex® XE2-B from Orion Engineered Carbons are suitable in the context of the present invention.

By graphitic layers, which are incorporated in the amorphous carbon, soot has sufficient conductivity. The current is conducted within the soot particles and see between individual particles, if the distance is sufficiently low. In order to achieve sufficient conductivity with minimal amounts of soot, carbon black with anisotropic structures is preferably used. In the case of such carbon black, the required conductivity is already achieved with a small proportion of the carbon black in the finished material. Suitable materials are described in D. Pantea et al., Applied Surface Science 2003, 217, 181-193.

The electrical conductivity increases with increasing carbon black concentration, while the electrical resistance decreases accordingly. The inventively suitable carbon black is used in amounts such that the composition (Z1) 5 to 30 wt .-%, preferably 7 to 25 wt .-% carbon black, particularly preferably 10 to 20 wt .-% carbon black, based on the total weight of Composition (Z1), included.

According to the invention, the composition (Z1) may also contain graphene as conductivity-promoting additive. Graphene is a monolayer of carbon atoms arranged in a honeycomb-shaped structure. In the context of the present invention, however, the term graphene is understood to mean not only graphene within the meaning of the IUPAC definition, but a composition comprising monolayer material, two-ply material and multilayer material having 3 to 10 layers and in exceptional cases up to 20 layers. The ratio of the different components, ie monolayer material, two-ply material and multilayer material, depends on the manufacturing process. For the purposes of the present invention, the term graphene is understood to mean a material which is characterized by the absence of the graphite signal in an XRD measurement. The presence of a signal at 2theta = 25 to 30 ° (accurate signal at 26.3 °, with Cu Ka radiation, wavelength = 0.154 nm) results from the layer structure and is related to the proportion of graphite. Preferably, the corresponding measurement for the graph in the context of the present invention does not have a graphite signal. Accordingly, in the context of the present invention, the material preferably has no non-defoliated material.

"Graphene" in the context of the present invention is further characterized by a low density, preferably of at most 0.2 g / cm ³ , for example from 0.001 to 0.2 g / cm ³ or from 0.003 to 0.2 g / cm ³ , more preferably of at most 0.15 g / cm ³ , for example from 0.001 to 0.15 g / cm ³ or from 0.003 to 0.15 g / cm ³ , particularly preferably at most 0.1 g / cm ³ , for example from 0.001 to 0.1 g / cm ³ or from 0.003 to 0.1 g / cm ³ , in particular not more than 0.05 g / cm ³ , for example from 0.001 to 0.05 g / cm ³ or from 0.003 to 0, 05 g / cm ³ , and particularly preferably at most 0.01 g / cm ³ , for example from 0.001 to 0.01 g / cm ³ or from 0.003 to 0.01 g / cm ³ . "Graphene" in the sense of the present invention is further characterized by a high BET surface area (Brunauer-Emmett-Teller). Preferably, the BET surface area is greater than 200 m ² / g, for example in the range of 200 to 2600 or in the range of 200 to 2000 or in the range of 200 to 1500 m ² / g or in the range of 200 to 700 m ² / g; more preferably, the BET surface area is greater than 300 m ² / g, for example in the range from 300 to 2600 or in the range from 300 to 2000 or in the range from 300 to 1500 or in the range from 300 to 700 m ² / g.

In the context of the present invention, suitable "graphene" preferably has a high ratio of carbon atoms to oxygen atoms (C / O ratio). The elemental composition is represented by the ratio of carbon atoms to oxygen atoms in (C / O ratio) and is related to the degree of reduction of the graphene material. The ratio of carbon atoms to oxygen atoms is preferably at least 3: 1, more preferably at least 5: 1, particularly preferably at least 50: 1, in particular at least 100: 1 and preferably at least 500: 1, determined by the atomic fractions (at%) of the elements by X-ray photoelectron spectroscopy (XPS).

Suitable materials and methods of preparation are described, for example, in Macromolecules 2010, 43, pages 6515 to 6530, in WO 2009/126592, J. Phys. Chem. B 2006, 110, 8535-8539, Chem. Mater. 2007, 19, 4396-4404 and in the prior art cited therein.

The content of graphene in the composition (Z1) used in the invention is preferably in the range of 0.1 to 20 wt .-%, more preferably in the range of 0.5 to 15% by weight, particularly preferably in the range of 1 to 10 Wt .-%, more preferably in the range from 1 to 7 wt .-% or in the range of 2 to 7 wt .-%, each based on the total weight of the composition (Z1).

In the context of the present invention, the composition (Z1) particularly preferably contains, in addition to graphene, no further carbon-based conductivity-conferring additives.

The composition (Z1) used according to the invention can be prepared in a manner known per se, the preparation preferably taking place by means of a kneader or an extruder, for example a twin-screw extruder.

For the incorporation of the additives (A1), the so-called "Feed Enhancement Technology" (FET) can be used, as described by Paul Anderson in "Plastics Research Online", Soc. of Plastic Engineers (2011), 10.1002 / spepro.003681 or in US 20080248152 and in US

20100202243 is described. Extruders with the FET technique are commercially available from Copeion GmbH, Stuttgart.

In addition, to improve the distribution of added additives, processing aids, such as surface-active substances, e.g. anionic, cationic or nonionic surfactants are used.

According to the invention, the elongation at break of the composition (Z1) used is greater than 300%, determined in accordance with DIN 53504. The elongation at break is preferably greater than 500% and particularly preferably greater than 600%.

Accordingly, the present invention also relates to the use of a composition (Z1) as described above, wherein the composition (Z1) has an elongation at break, determined according to DIN 53504, in the range of greater than 500%. In preferred embodiments, the composition (Z1) used according to the invention is further characterized in that at least one of the following properties is fulfilled:

The tensile strength is greater than 5 MPa, preferably greater than 10 Pa, and particularly preferably greater than 20 MPa.

The tear propagation resistance is greater than 10 kN / m, preferably greater than 15 KN / m and particularly preferably greater than or equal to 25 kN / m. The abrasion is less than 100 mm ³ , preferably less than 70 mm ³ and particularly preferably less than 55 mm ³ . - The compression set is less than 40% at 23 ° C, preferably less than 30% and more preferably less than 24%.

- The compression set at 70 ° C is less than 50%, preferably less than 35%, and more preferably less than 25%.

- The bending angle at 23 ° C is less than 50%, preferably less than 30% and more preferably less than 20%. In particularly preferred embodiments, the composition (Z1) has at least two of the abovementioned properties, more preferably at least three, more preferably at least four, more preferably at least 5, even more preferably at least 6, and most preferably all 7 of the above properties. Any combination of properties with the same or different preferences also belongs to the scope of disclosure of this document, eg "preferred" with "preferred", but also "preferred" with "particularly preferred" etc., even if not each of these combinations for reasons of clarity is explicitly mentioned. Most preferably, the polyurethanes according to the invention have a tensile strength of more than 20 MPa, an elongation at break of more than 500%, a tear resistance of greater than or equal to 25 kN / m, an abrasion of less than 55 mm ³ , a compression set of less than 24%. at 23 ° C and less than 25% at 70 ° C.

The polyurethanes contained in the composition (Z1) used according to the invention preferably have a coefficient KZ between 980 and 1200, preferably between 980 and 1100, particularly preferably between 990 and 1050.

According to the invention, the Shore A hardness of the composition (Z1) used according to the invention is in the range from 30 to 95, preferably in the range from 40 to 85, particularly preferably in the range from 45 to 80, in each case according to DIN 53505.

According to a further embodiment, the present invention thus also relates to the use of a composition (Z1) as described above, wherein the composition (Z1) has a Shore A hardness, determined according to DIN 53505, in the range from 40 to 85. Furthermore, the composition (Z1) used according to the invention has an electrical volume resistivity, determined according to ISO 3915, in the range of less than 1x10 ² ohm.cm and more than 0.01 ohm.cm. The electrical volume resistivity, determined in accordance with ISO 3915, is preferably in the range from 0.01 to 100 ohm.cm, preferably in the range from 0.05 to 50 ohm.cm, more preferably in the range from 0.05 to 10 ohm.cm. , most preferably in the range of 0.1 to 5 ohm.cm.

According to the invention, the composition (Z1) is used for the production of moldings in the automotive sector, for example rollers, claddings in automobiles, hoses, Ββ · Laminations, profiles, laminates, bellows, trailing cables, scrapers, sealing lips, cable sheathing, gaskets, belts, frames, housings, containers, nozzle shells or damping elements produced by injection molding, calendering, hot pressing, powder sintering or extrusion.

According to a further embodiment, the present invention also relates to the use of a composition (Z1) as described above, wherein the composition (Z1) for producing a scraper, a wiper blade, a sealing lip, a steering wheel, a gasket or a component for a car seat or a Armrest is used.

Furthermore, the present invention relates to a method for producing an electrically heatable molding for the automotive sector, comprising the steps

(i) providing a composition (Z1) containing at least an elastomer (E1) and an at least 90% carbon-based conductivity-imparting additive (A1) for producing an electrically heatable molded article for automobile use, said composition (Z1) having the following properties :

a Shore hardness A, determined to DIN 53505, in the range of 30 to 95, an electrical volume resistivity, determined according to ISO 3915, of less than 1 × 10 ² ohm x cm, and greater than 0.01 Ohm x cm, and an elongation at break, determined in accordance with DIN 53504, greater than 300%,

(ii) Shaping the composition (Z1).

With regard to the preferred embodiments, reference is made to the above statements.

According to the invention, the composition (Z1) is produced on a kneader or twin-screw extruder from an elastomer (E1), preferably a thermoplastic polyurethane, and the conductivity-promoting additive (A1). In the context of the present invention, the conductivity-imparting additive (A1) according to a further embodiment may also be added in the form of a concentrate to the elastomer (E1) before molding.

According to step (ii), shaping takes place. In the context of the present invention, it is preferred, for example, for the composition (Z1) to be melted and processed in an extruder or in an injection molding or pressing process.

In the context of the present invention, it is also possible that the molded article produced is merely a part of a component, and the composition (Z1) is applied, for example, to an existing frame.

The present invention also relates to electrically heatable moldings for the automotive sector comprising a composition (Z1) at least containing an elastomer (E1) and an at least 90% carbon-based conductivity-promoting additive (A1) for producing an electrically heatable molded article for the automotive sector, the composition (Z1) having the following properties:

a Shore hardness A, determined to DIN 53505, in the range of 30 to 95, - an electrical volume resistivity, determined according to ISO 3915, of less than 1 × 10 ² ohm x cm, and greater than 0.01 Ohm x cm, and

According to the invention, the shaped body is preferably a scraper, a wiper blade, a sealing lip, a steering wheel, a component for a car seat or an armrest or a seal. Accordingly, the present invention also relates to moldings as described above, wherein the molded body is a scraper, a wiper blade, a sealing lip, a steering wheel, a component for a car seat or an armrest or a seal. The compositions used according to the invention or the shaped bodies obtained according to the invention are preferably heatable to a temperature in the range from 0 ° C. to 100 ° C., more preferably to a temperature in the range from 10 ° C. to 60 ° C., in particular to a temperature in the range from 15 ° C to 50 ° C, and more preferably in the range of 20 to 40 ° C. In this case, according to a preferred embodiment, in the case of a shaped body with a cross-section of 10 mm ^2, a surface temperature of 30 ° C. occurs within 5 minutes after applying a voltage of 12V over a passage of 10 cm.

In this case, according to the invention at least two contacts are provided to heat the molding by a voltage is applied. It is also possible that a current flows through only part of the molded body or that more than two contracts are present, for example 3, 4, 5 or 6 contacts. For example, an extruded wiper blade can be produced from a composition (Z1) and this can be provided with an electrical connection at the beginning and at the end. By applying low voltage from the car electrical system, such a wiper blade can be heated up to 60 ° C, the desired temperature can be adjusted by a series resistor or a voltage control. On such heated wiper blades forms no more ice at temperatures below freezing and the well-known for thermoplastic elastomers stiffening well below 0 ° C can also be prevented by the material-internal heating. According to a further embodiment, the present invention accordingly also relates to a shaped body as described above, wherein the shaped body is heated by applying a DC or AC voltage from the automotive electrical system. Furthermore, according to a further embodiment, the present invention also relates to a shaped body as described above, wherein the temperature control of the shaped body takes place by adaptation of the voltage or change of a series resistor.

The present invention also relates to a method for electrically heating a molding for the automotive sector by applying a DC or AC voltage from the Automotive electrical system. Furthermore, the present invention also relates to a method for controlling the temperature of a molded article for the automotive sector, wherein the temperature control is carried out by adjusting the voltage or change a series resistor. Further embodiments of the present invention can be taken from the claims and the examples. It is understood that the above-mentioned and explained below features of the subject invention method A / uses not only in the particular combination given, but also in other combinations can be used without departing from the scope of the invention. So z. For example, the combination of a preferred feature with a particularly preferred feature, or a non-further characterized feature with a particularly preferred feature, etc. implicitly includes, even if this combination is not explicitly mentioned.

Use of a composition (Z1) at least comprising an elastomer (E1) and an at least 90% carbon-based conductivity-conferring additive

(A1) for producing an electrically heatable shaped article for the automobile sector, the composition (Z1) having the following properties:

2. Use of a composition (Z1) according to embodiment 1, wherein the

Elastomer (E1) is a thermoplastic polyurethane.

3. Use of a composition (Z1) according to embodiment 1 or 2, wherein the elastomer (E1) is a thermoplastic polyurethane based on at least one isocyanate, at least one polyol component having a molecular weight greater than 500 g / mol and at least one second polyol component with a Molecular weight of less than 499 g / mol, is.

Use of a composition (Z1) according to any one of embodiments 1 to 3, wherein the at least 90% carbon-based conductivity-conferring additive (A1) is selected from the group consisting of carbon nanotubes, graphene and conductivity carbon black, and mixtures thereof.

Use of a composition (Z1) according to any one of embodiments 1 to 4, wherein as the at least 90% carbon-based conductivity-promoting additive (A1) carbon nanotubes are used.

Use of a composition (Z1) according to one of embodiments 1 to 5, wherein the at least 90% carbon-based conductivity-promoting additive tiv (A1) in the composition (Z1) in an amount ranging from 0.1 to 30% by weight based on the entire composition (Z1).

Use of a composition (Z1) according to one of embodiments 1 to 6, wherein the composition (Z1) has a Shore A hardness, determined according to DIN 53505, in the range from 40 to 85.

Use of a composition (Z1) according to one of embodiments 1 to 7, wherein the composition (Z1) has an elongation at break, determined according to DIN 53504, in the range of greater than 500%.

Use of a composition (Z1) according to one of embodiments 1 to 8, wherein the composition (Z1) has a volume resistivity, determined according to ISO 3915, in the range of 0.1 to 5 ohm.cm. Use of a composition (Z1) according to any one of embodiments 1 to 9, wherein the composition (Z1) is used for producing a scraper, a wiper blade, a sealing lip, a steering wheel, a gasket or a component for a car seat or an armrest. A process for producing an electrically heatable shaped article for the automotive sector, comprising the steps

(i) providing a composition (Z1) containing at least an elastomer (E1) and an at least 90% carbon-based conductivity-promoting additive (A1) for producing an electrically heatable molding for the automotive sector, the composition (Z1) comprising the following Features:

(ii) Shaping the composition (Z1). An electrically heatable molded article for the automotive sector comprising a composition (Z1) containing at least one elastomer (E1) and at least 90%

A carbon-based conductivity-promoting additive (A1) for producing an electrically heatable molded article for the automotive sector, the composition (Z1) having the following properties:

an elongation at break, determined according to DIN 53504, of greater than 300%. 13. Shaped body according to embodiment 12, wherein the shaped body is a scraper, a wiper blade, a sealing lip, a steering wheel, a component for a car seat or an armrest or a seal. 14. Shaped body according to embodiment 12 or 13, wherein the shaped body is heated by applying a DC or AC voltage from the automotive electrical system.

15. Shaped body according to one of the embodiments 12 to 14, wherein the temperature control of the shaped body by adjusting the voltage or change of a Vorwider- state takes place.

16. Use of a composition (Z1) comprising at least one elastomer (E1) and at least 90% carbon-based conductivity-promoting additive (A1) for producing an electrically heatable molding for the automotive sector, wherein the at least 90% carbon-based conductivity-promoting additive (A1) is selected from the group consisting of carbon nanotubes, graphene and mixtures thereof and

wherein the composition (Z1) has the following properties:

17. Use of a composition (Z1) according to embodiment 16, wherein as the at least 90% based on carbon conductivity-promoting additive (A1) carbon nanotubes are used.

18. Use of a composition (Z1) according to one of the embodiments 16 or 17, wherein the at least 90% carbon-based conductivity-promoting additive (A1) in the composition (Z1) in an amount in the range of 2 to 7 wt.

%, based on the total composition (Z1).

19. An electrically heatable molding for the automotive sector comprising a composition (Z1) comprising at least one elastomer (E1) and an at least 90% carbon-based conductivity-promoting additive (A1) for producing an electrically heatable molding for the automotive sector, wherein the at least 90 % carbon-based conductivity-promoting additive (A1) is selected from the group consisting of carbon nanotubes, graphene and mixtures thereof and

wherein the composition (Z1) has the following properties:

a Shore hardness A, determined to DIN 53505, in the range of 30 to 95, an electrical volume resistivity, determined according to ISO 3915, of less than 1 × 10 ² ohm x cm, and greater than 0.01 Ohm x cm, and an elongation at break, determined according to DIN 53504, of greater than 300%.

Shaped body according to embodiment 19, wherein the shaped body is a scraper, a wiper blade, a sealing lip, a steering wheel, a component for a car seat or an armrest or a seal.

Shaped body according to embodiment 19 or 20, wherein the shaped body is heated by applying a DC or AC voltage from the automotive electrical system.

Shaped body according to one of the embodiments 19 to 21, wherein the temperature control of the shaped body is carried out by adjusting the voltage or change of a series resistor.

In the following the invention will be explained in more detail by means of examples. EXAMPLES 1. Feedstocks

Various TPU formulations were used for the experiments. The starting materials are listed below.

1.1 TPU1

A thermoplastic polyurethane (TPU) with a Shore hardness of about 85 A is from 344 parts of 4,4'-diphenylmethane diisocyanate, 72.2 parts of chain extender butanediol-1, 4 and 573 parts of polytetrahydrofuran having a number average molecular weight of 1 kg / mol a reaction extruder synthesized, wherein the zone temperatures of the extruder between 140 ° C and 210 ° C. Further, 10 parts of a phenolic antioxidant and 25 ppm of a 25% solution of dioctyl adipate of tin dioctoate are added as a reaction catalyst. The resulting TPU is transformed into lentil granules by means of underwater granulation and dried.

TPU2

A thermoplastic polyurethane (TPU) with a Shore hardness of about 70 A is from 256 parts of 4,4'-diphenylmethane diisocyanate, 45.3 parts of chain extender butanediol 1.4 and 688 parts of polytetrahydrofuran having a number average molecular weight of 1, 5 kg / mol in a reaction extruder synthesized, wherein the zone temperatures of the extruder between 140 ° C and 210 ° C. Furthermore, 10 parts of a phenolic antioxidant, 5 parts of ester wax and 25 ppm of a 25% solution of dioctyl adipate of stannous oxide are added. toat added as a reaction catalyst. The resulting TPU is transformed into lentil granules by means of underwater granulation and dried. TPU3

A thermoplastic polyurethane (TPU) with a Shore hardness of about 60 A is from 199 parts of 4,4'-diphenylmethane diisocyanate, 25 parts of chain extender monoethylene glycol and 764 parts of a polymer diol of adipic acid, Ethandioll, 2, butanediol 1.4, the latter in mass ratio 1: 1, the number average molecular weight of 2000 g / mol synthesized in a reaction extruder, the zone temperatures of the extruder between 140 ° C and

210 ° C lie. Furthermore, 7.6 parts of a hydrolysis stabilizer (oligomeric carbodiimide of TMDXI = tetramethylxylyl diisocyanate), 2 parts of a phenolic antioxidant and 3 parts of a lubricant (partially hydrolyzed montanic acid ester) are added during the reaction. The resulting TPU is transformed into lentil granules by means of underwater granulation and dried. CNT: Nanocyl NC7000, carbon nanotubes from Nanocyl SA, Belgium CB: Carbon Black, Printex XE 2B from Orion Engineered Carbons, Germany

Production Examples Example 1

A mixture of 97 parts by weight of TPU1 and 3 parts by weight of CNT was compounded on a co-rotating 27 mm 2 Leistritz ZSE Maxx 27 screw extruder, extruded into a strand and then granulated. The resulting uniformly colored granules were placed on an Arenz 30mm extruder

(Company Arenz Germany) using a profile tool continuously processed to wiper blade profiles of about 10mm2 cross-section. Of these, a section of 10 cm in length was taken, contacted at the ends with conductive silver and applied according to the voltage described in Table 2 and the resulting temperature measured by means of an infrared camera time-dependent.

On a corresponding machine with a flat film die, the material was continuously processed into a 10 cm wide and 1, 5 mm thick film.

Subsequently, specimens were punched out of the film and the specific passage resistance was determined in accordance with ISO 3915.

Example 2 A mixture of 85 parts by weight of TPU1 and 15 parts by weight of CB was compounded on a co-rotating 2-screw extruder Berstorff ZE 40, and then granulated under water.

The resulting uniformly colored granules were processed continuously on a Arenz 30 mm extruder (Arenz Germany) by means of a profile tool into wiper blade profiles of approximately 10 mm 2 cross-section. Of these, a section of 10 cm in length was taken, contacted at the ends with conductive silver and applied according to the voltage described in Table 2 and the resulting temperature measured by means of an infrared camera time-dependent.

Subsequently, specimens were punched out of the film and the specific volume resistance was determined in accordance with ISO 3915.

Example 3

A mixture of 97 parts by weight of TPU2 and 3 parts by weight of CNT was compounded on a co-rotating 27 mm 2 Leistritz ZSE Maxx 27 screw extruder, extruded into a strand and then granulated.

The resulting uniformly colored granules were processed continuously on a Arenz 30 mm extruder from Arenz Germany) by means of a flat film die into a 10 cm wide and 1.5 mm thick film.

Example 4

A mixture of 95 parts by weight of TPU2 and 5 parts by weight of CNT was compounded on a co-rotating Leistritz ZSE Maxx 27 27 mm 2 screw extruder, extruded into a strand and then granulated.

The resulting uniformly colored granules were processed continuously on a Arenz 30 mm extruder (Arenz Germany) by means of a profile tool into wiper blade profiles of approximately 10 mm 2 cross-section. Of these, a section of 10 cm in length was taken, contacted at the ends with conductive silver and applied according to the voltage described in Table 2 and the resulting temperature measured by means of an infrared camera time-dependent On a corresponding machine with a flat film die, the material was continuously processed into a 10 cm wide and 1, 5 mm thick film.

2.5 Example 5

A mixture of 97 parts by weight TPU3 and 3 parts by weight CNT was compounded on a concomitant Leistritz ZSE Maxx 27 27 mm 2 screw extruder, extruded into a strand and then granulated.

The resulting uniformly colored granules were processed continuously on a Arenz 30 mm extruder (Arenz Germany) by means of a flat film die into a 10 cm wide and 1.5 mm thick film.

Subsequently, specimens were punched out of the film and the specific volume resistance was determined in accordance with ISO 3915. 2.6 Example 6

A mixture of 95 parts by weight TPU3 and 5 parts by weight CNT was compounded on a co-rotating 27 mm 2 Leistritz ZSE Maxx 27 screw extruder, extruded into a strand and then granulated.

The resulting uniformly colored granules were processed continuously on a Arenz 30 mm extruder (Arenz Germany) by means of a profile tool into wiper blade profiles of approximately 10 mm 2 cross-section. From each of which a section of 10cm in length was taken, contacted at the ends with conductive silver and applied a voltage according to Table 2 described and the resulting temperature by means of a

Infrared camera measured time-dependent.

On a corresponding machine with a flat film die, the material was continuously processed into a 10 cm wide and 1.5 mm thick film.

Subsequently, specimens were punched out of the film and the specific volume resistance was determined in accordance with ISO 3915. 3. Results / readings

Table 1 shows the results of the volume resistance measurement according to ISO 3915. Example DuWi [Dem]

1 6

2 4

3 12

4 4

5 15

6 4

Table 2 shows summarized voltages and the resulting temperatures, which were measured time-dependent by means of an infrared camera.

Voltage 12V 24V

Temperature after 1 min after 5 min after 1 min after 5 min

Example 1 27 ° C 31 ° C 37 ° C 57 ° C

Example 2 33 ° C 43 ° C 55 ° C> 80 ° C

Example 4 31 ° C 41 ° C 54 ° C> 80 ° C

Example 6 32 ° C 42 ° C 57 ° C> 80 ° C

Claims

Patent claims

Use of a composition (Z1) containing at least one elastomer (E1) and a conductivity-promoting additive (A1) based on at least 90% carbon for producing an electrically heatable molded body for the automotive sector, the composition (Z1) having the following properties:

a Shore hardness A, determined according to DIN 53505, in the range from 30 to 95, an electrical specific volume resistance, determined according to ISO 3915, of less than 1x 10 ² Ohm x cm and greater than 0.01 Ohm x cm, as well

Use of a composition (Z1) according to claim 1, wherein the elastomer (E1) is a thermoplastic polyurethane.

Use of a composition (Z1) according to claim 1 or 2, wherein the elastomer (E1) is a thermoplastic polyurethane based on at least one isocyanate, at least one polyol component with a molecular weight of greater than 500 g/mol and at least one second polyol component with a molecular weight of less than 499 g/mol, is.

Use of a composition (Z1) according to one of claims 1 to 3, wherein the at least 90% carbon-based conductivity-imparting additive (A1) is selected from the group consisting of carbon nanotubes, graphene and conductivity carbon black and mixtures thereof.

Use of a composition (Z1) according to one of claims 1 to 4, wherein carbon nanotubes are used as the at least 90% carbon-based conductivity-imparting additive (A1).

Use of a composition (Z1) according to one of claims 1 to 5, wherein the at least 90% carbon-based conductivity-imparting additive (A1) in the composition (Z1) in an amount in the range of 0.1 to 30% by weight, based on the entire composition (Z1).

Use of a composition (Z1) according to one of claims 1 to 6, wherein the composition (Z1) has a Shore hardness A, determined according to DIN 53505, in the range from 40 to 85.

Use of a composition (Z1) according to one of claims 1 to 7, wherein the composition (Z1) has an elongation at break, determined according to DIN 53504, in the range of greater than 500%.

9. Use of a composition (Z1) according to one of claims 1 to 8, wherein the composition (Z1) has an electrical specific volume resistance, determined according to ISO 3915, in the range of 0.1 to 5 ohm x cm.

10. Use of a composition (Z1) according to one of claims 1 to 9, wherein the composition (Z1) is used to produce a wiper, a wiper blade, a sealing lip, a steering wheel, a seal or a component for a car seat or an armrest.

11. Process for producing an electrically heatable molded body for the automotive sector, comprising the steps

(i) Providing a composition (Z1) containing at least one elastomer (E1) and a conductivity-imparting additive (A1) based on at least 90% carbon for producing an electrically heatable molded body for the automotive sector, the composition (Z1) having the following Features:

a Shore hardness A, determined according to DIN 53505, in the range from 30 to 95, an electrical specific volume resistance, determined according to ISO 3915, of less than 1x 10 ² Ohm x cm and greater than 0.01 Ohm x cm, and an elongation at break, determined according to DIN 53504, greater than 300%,

(ii) Shaping the composition (Z1). 2. Electrically heatable molded body for the automotive sector comprising a composition (Z1) containing at least one elastomer (E1) and at least 90%

Carbon-based conductivity-imparting additive (A1) for producing an electrically heatable molded body for the automotive sector, the composition (Z1) having the following properties:

a Shore hardness A, determined according to DIN 53505, in the range from 30 to 95, - an electrical specific volume resistance, determined according to ISO 3915, of less than 1x 10 ² Ohm x cm and greater than 0.01 Ohm x cm, as well

13. Shaped body according to claim 12, wherein the shaped body is a wiper, a wiper blade, a sealing lip, a steering wheel, a component for a car seat or an armrest or a

Seal is.

14. Shaped body according to claim 12 or 13, wherein the shaped body is heated by applying a direct or alternating voltage from the automobile electrical system.

15. Shaped body according to one of claims 12 to 14, wherein the temperature control of the shaped body takes place by adjusting the voltage or changing a series resistor.