EP3997176A1

EP3997176A1 - Ternary polymer blend, in particular for pipe extrusion, thermoplastic plastics pipe made from such a blend, and use thereof

Info

Publication number: EP3997176A1
Application number: EP20734687.5A
Authority: EP
Inventors: Heinz Spelthann; Daniel DE BEER
Original assignee: Voss Automotive GmbH
Current assignee: Voss Automotive GmbH
Priority date: 2019-07-11
Filing date: 2020-06-22
Publication date: 2022-05-18
Also published as: WO2021004764A1; DE102019118856A1; CN114040944B; CN114040944A

Abstract

The invention relates to a thermoplastic polyamide-polyolefin blend, in particular for the extrusion of pipes intended for conveying fluid, said blend at least containing a polyolefin, a polyamide and a compatibiliser. In order to achieve high media resistance, in particular with respect to cooling water and aqueous zinc chloride solutions, and to guarantee a good extrusion performance of the blend and make it possible to fit a plastics pipe produced from the blend on mandrels as pipe connector elements, all while optimising the ratio of requirement profile to manufacturing outlay, the invention provides for the polyolefin to be a polypropylene-based thermoplastic elastomer, which is present in a mass ratio to the polyamide in the range from 0.05 to 5.0, the compatibiliser content being in a range from 7.5 to 50 parts by mass, in relation to 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide, and the compatibiliser containing, as at least a first component, a partially neutralised ionomer which is a copolymer containing ethylene monomer and acrylic acid monomer units.

Description

Voss Automotive GmbH, Leiersmühle 2-6, D-51688 Wipperfürth

"Ternary polymer blend, especially for pipe extrusion, thermoplastic plastic pipe made from such a blend and its use"

The present invention relates to a thermoplastic polyamide-polyolefin blend, in particular for the production of fluid-carrying pipes by extrusion, at least containing a polyolefin, a polyamide and a compatibilizer. The invention also relates to a plastic pipe made from such a blend and its use.

Fluid-carrying line systems, which are used in particular in motor vehicles as

Line sections pipes - or hoses in flexible training - aulweise, which via line connectors, such as. B. mandrels, interconnectable or connected, are subject to a variety of requirements. Such line systems can in particular means for generating pressure, such. B. pumps or compressors, by means of which the fluid is conveyed through the system. This results in requirements with regard to pressure resistance. By using means for generating or dissipating heat, heating or cooling can be provided. From this and by changing the

Environmental conditions result in requirements in terms of

Temperature resistance.

In addition to the requirements in operation, such as limited fluid absorption, especially water absorption, high heat resistance, one that is adapted to the fluid pressure Pressure resistance, high shear strength, etc., demands are placed on the pipe sections with regard to processability, such as B. in terms of their malleability. For example, it must be possible to flare a pipe onto the mandrel of a connector. The pipe must not tear in or out, whereby - so that the pipe does not tear when it is thrown open - a certain elasticity of its

Wall must be present. In addition, the wall of the pipe must have a certain resetting behavior - from the expanded state that occurs during the expanding process - so that, in particular without the use of further fastening means, such as. B. by hose clamps, a tight fit on the mandrel. For example, pure polyolefin pipes do not meet this requirement because they have too high a tendency to creep, which is unsuitable for mandrel connections.

The pipe must also be resistant to media. So z. B a certain zinc chloride resistance must be guaranteed, especially in cooling water applications. This is determined according to the standard SAE J 2240-2008. PA 6 and PA 66 as well as their blends with polyolefins do not meet this media resistance. These materials are also resistant to hydrolysis at cooling water temperatures>

100 ° C is not sufficient.

Flame protection is also required for some applications.

Numerous technical solutions of the most varied types are known in order to meet the specified requirement profile through the parameters to be observed during operation, such as temperature and pressure, as well as through the conditions that arise during production and assembly according to the method. Pipes known from practice for cooling water applications are for example by

Extrusion of a polyamide, in particular with a wall made of PA12. With regard to the use of material in the pipe wall, at least three options for setting an optimal balance between the requirement profile and manufacturing costs can be differentiated.

As the first such possibility, the German utility model of the applicant DE 20 2011 110 917 U1 describes a heatable fluid line that has at least two length sections that are different in terms of their material properties and / or their structural shape, on the one hand at least a first length section consisting of consists of a first material containing a first polymer, and on the other hand a second

Length section which consists of a second material which contains a second polymer, the material of the second length section being more flexible and / or having a higher strength than the material of the first length section. Thereby a differentiated structuring of the line takes place, i. H. the various lengths of the line are designed according to the locally different requirements. This technical solution has proven itself in practice. The material of the first length section can in particular contain a polymer that is an engineering plastic, while the material of the second length section can in particular contain a polymer that is a high-performance plastic.

If the expressions "engineering plastic" and "high-performance plastic" are used, these expressions relate to a classification of plastics with regard to their long-term service temperature that is customary in the specialist field. After that, between mass and standard plastics with a

Continuous use temperature up to 90 ° C, engineering plastics with a continuous use temperature up to 140 ° C and high-performance plastics with a

Continuous use temperature over 140 ° C differentiated. The continuous use temperature can be determined in various ways. In the method according to UL 746 B a so-called temperature index is given, ie the temperature is determined at which the polymer material still has half its tensile strength after 60,000 or 100,000 hours

Has tensile impact strength or its dielectric strength. An analogous method is the I EC 216 (International Electrical Committee), which corresponds to DIN VDE 0304. This method is used to determine the temperature at which, after 20,000 hours, the values of the mechanical and electrical properties are only half.

Based on these criteria, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polymethacrylic acid methyl ester (PMMA), acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS) are classified as bulk plastics.

Engineering plastics include polyamide (PA), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate (PC) and polyoxymethylene (POM).

The high-performance plastics include polytetrafluoroethylene (PTFE),

Polyvinylidene fluoride (PVDF), polysulphones (PSU), polyaryl ether ketones (PAEK), polyphenylene sulphides (PPS) and polyimides (PI) as well as various copolymers which together contain the smallest repeating chain structural units of the aforementioned compounds. Since these high-quality polymers are very complex to manufacture and consequently expensive, their use is limited to certain special cases. For this reason, despite their excellent properties, these materials are rarely or not at all used for the production of known fluid lines. According to DE 20 2011 110 917 U1, a polyamide (PA), in particular PA 6, PA 66, PA 11 or PA 12, can advantageously be selected as the polymer material of the first length section, which results in a low-cost production of the Fluid line according to the invention can be guaranteed. Polyamides are generally classified as engineering plastics, but they can also be given by a special design of their formulation, e.g. B. by copolymerization, the properties of high-performance plastics are given. The first length section can be designed, for example, as a plastic molded tube, with filled engineering plastics such. B. fiber-reinforced plastics can be used.

According to DE 20 2011 110 917 U1, the polymer of the second length section can advantageously be an elastomer, for example hydrogenated acrylonitrile butadiene rubber (HNBR), ethylene-propylene-diene rubber (EPDM) for a temperature load of up to 170 ° C, an ethylene-propylene - Rubber (EPM) for temperatures above 200 ° C or a thermoplastic elastomer (TPE). From this material class, PA 12 elastomers appear particularly suitable. These are block copolymers made from PA 12 and from polyether segments (polyether block amides PEBA). They show the essential properties of PA12, whereby the elastomeric character becomes more and more pronounced with increasing polyether content. The polymers become elastically more flexible and tougher at low temperatures.

In addition to the pipe design with sequential, section-wise material changes as a first possibility for setting a balance between the requirement profile and the manufacturing wall, the utility model DE 20 2011 110 917 U1 also describes a preferred embodiment of a first length section of a fluid line with a second option for achieving an optimal balance between the requirement profile and manufacturing effort . In this version, the Pipe wall constructed in two layers. It comprises an outer wall, preferably made of an engineering plastic such as PA 12, and an inner wall, preferably made of a fluoropolymer such as PTFE. The

Inner wall can preferably be comparatively thin in the sense of only a superficial coating of the outer wall, i. H. approximately with a maximum wall thickness of 300 µm, the comparatively thicker outer wall ensuring the required mechanical stability. When advantageous

Material-economical production method - mainly from the engineering plastic - the length section has a load-appropriate heat and cold resistance and, in particular due to the fluorine-containing polymer of the inner wall, an increased resistance to the fluid flowing in it, for example increased chemical resistance, especially with regard to water absorption and / or hydrolysis.

Pipes with multilayer made using polyamides

Walls are also described, for example, in EP 1 717 022 B1, EP 2 261 032 B1, EP 2 409 830 B1 and EP 2 842 736 A1.

A third known way of setting a balance between

The requirement profile and manufacturing effort is the use of compound or preferably polyblend polymers. Compounds are plastics to which additional fillers, reinforcing materials or other additives have been added. In this regard, a

Fiber reinforcement mentioned. The compounding thus firmly bonds at least two substances with one another. The aim of compounding is to

Modifying the properties of the plastics specifically for a specific application. For thermoplastics, compounding takes place in particular with the aid of

Twin-screw extruders in which the starting materials, which are usually in granular form, are melted and intimately mixed. If two polymers are compounded, this creates a so-called one

Polyblend. Such a polyblend - also known as a polymer alloy (English: "alloy") - is a special compound, but a compound is not always a blend. Specific types of blends are mixtures of polyolefins, such as polyethylene (PE) and / or polypropylene (PP), which due to the above. Criteria under which mass plastics are to be classified, with polyamides as representatives of the higher-quality technical or even - as mentioned above - possibly the

High performance plastics.

An analysis of the known state of the art for the production of polyblends shows that the 1970s in particular were a period in which many patent applications were made in the field of PA-PE blends. DE 42 23 864 A1, which deals with the recycling of PA / PE waste, provides a relatively comprehensive overview of this state of the art. It is stated there that polyamide-polyolefin blends, especially polyamide-polyethylene blends, have been known to the person skilled in the art for years. These polymer alloys are characterized by the fact that polyamide with 5 to 40

% By weight polyethylene with the aid of a process for compatibilization, such as the use of peroxides, block copolymers or specially selected compatibilizers. These blends are characterized e.g. B. by increased impact strength and reduced water absorption. Likewise, the production of high-impact polyamides by compounding polyamide is known exclusively with modified polyolefins, especially with acid- or anhydride-functional polyethylenes. The production of such polyamide blends is e.g. B. described in: Kunststoffe 65 (1975), p. 139 ff, Kunststoffe 80 (1991), p 838 ff, EP 0 469 693 A2 and in the literature cited therein - z. B. EP 0 235 876 A2, EP 0 245 964 A2, EP 0 270 247 A2, EP 0 272 695 A2, EP 0 335 649 A2 - as well as in WO 8908120 A1, JP 012 845 552 A, WO 9107467 A1 and US 3 484 403 A. It will stated that (despite the familiarity of the various processes) a careful balancing of the individual components is necessary in each case in order to obtain optimal properties. In fact, such a property optimization with often more than one target variable represents a coordinated setting of influencing variables comprising several parameters, which the normal activity of a person skilled in the art can often exceed.

A special challenge is that - since one polymer acts as a "high molecular weight" solvent for the other in a mixture of two different polymers - the possibilities for arranging the polymer segments are often drastically reduced, so that a strongly restricted or a non- The result is miscibility of the polymers, which is shown thermodynamically, for example, in the enthalpy of mixing of different homopolymers which deviates from zero. The entropy of mixing is also used as a measure.

Even saturated hydrocarbon polymers are usually not miscible with one another despite the same structural unit (-CH2-) that repeats in them and despite their chemical similarity. Also the mutual solubility depends on

Polyolefins depend on the chemical structure of the polymer chain, such as from

Degree of branching of the chain, its length and the position of side groups.

Even with copolymer pairings specially developed for the compatibilization of blend constituents - depending on the composition of the mixture and the temperature - there are also miscibility doors and windows as well as of

Immiscibility doors spoken in the phase diagram. Often there is only a miscibility in a certain proportion of the constituents of the mixture. The percentage of different types of polymer in a blend is therefore very important. However, the miscibility, which according to thermodynamics is understood to be complete single-phase, must be distinguished from a general compatibility of the different polymers. Polymers are compatible when the corresponding blends show the desired properties without having to be completely homogeneously miscible. They can therefore also be designed in two or more phases, with one of the polymers being able to form a matrix for the other polymer and any other ingredients that may be present. A prerequisite for this, however, is the provision of a suitable compatibilizer tailored to the constituents of the mixture. However, it can also be assumed that the quantitative proportions of the constituents are highly significant.

A polyamide-polyolefin blend similar to the type mentioned above is known from DE 603 02 719 T2. It describes flame-retardant compositions which - based on the weight, the total amount being 100 parts - contain the following components: 50 to 75 parts of the mixture of polyamide and polyolefin and 25 to 50 parts of the mixture containing: 0.1 to 48.8 parts of a flame retardant, 0.1 to 30 parts of a phosphorus

Plasticizer, 0.1 to 10 parts of a zeolite, the total of these three products being between 25 and 50 parts. To make polyamide and polyolefin compatible, functionalization of the polymers through the use of copolymers is apparently intended - although not expressly emphasized. These compositions are said to be suitable for protecting electrical cables and optical fibers and for molding electrical housings and preventers and therefore have an insulating effect.

A polyamide-polyolefin blend of the type mentioned at the beginning is known from DE 60 2004 001 610 T2. Therein the use of constructions with at least one layer of a mixture of polyamide and containing nanofillers Described polyolefin, wherein the polyamide forms the matrix, and where at least one layer of another material is optionally present to achieve a barrier effect. The mixture is thermoplastic and can be used to make bottles, tanks, containers, pipes and vessels of all kinds. An ethylene-butyl acrylate-maleic anhydride copolymer and a polypropylene are described as compatibilizers

Maleic anhydride was grafted and then condensed with a monoamino-PA6 as described in US Pat. No. 5,342,886.

The present invention is based on the object of providing a polyamide-polyolefin blend, in particular for the production of fluid-carrying pipes, of the generic type mentioned at the outset, and one produced therefrom, preferably as

To create a cooling water pipe in an automobile usable plastic pipe with in particular a single-layer wall, wherein an optimization of the ratio of requirement profile to manufacturing effort should take place, preferably with the lowest possible manufacturing effort

Resistance to media, especially to cooling water and aqueous media

Zinc chloride solutions and the blend is easy to process

Extruding and assembling the pipe on mandrels as

Pipe connector elements should be guaranteed. In addition, for the production of permanent mandrel connections in fluid-carrying line systems - at lower costs and high material availability - a similar expansion and creep behavior as that of PA 12 should be guaranteed.

According to the invention this is achieved in that the polyolefin is a

polypropylene-based thermoplastic elastomer, which is in one

Mass ratio in the range from 0.06 to 4.8 to the polyamide, the

Compatibilizer is contained in a range from 7.5 to 50 parts by weight based on 100 parts of the mixture of the polypropylene and the polyamide and contains a partially neutralized ionomer, which is a copolymer containing ethylene and acrylic acid monomer units.

Polypropylene-based thermoplastic elastomers are among the

olefin-based thermoplastic elastomers (TPE-O). They combine the properties of a semi-crystalline polyolefin and an amorphous elastomer component. It can in particular be a polymer blend with an uncrosslinked phase from the polymer which is dispersed in a polypropylene-containing matrix

Terpolymer Ethylene Propylene Diene Rubber (EPDM) act. In EPDM - used as a stand-alone material - the saturated main chain leads

Properties such as B. high weather and ozone resistance and high thermal resistance. Because of its good chemical resistance to polar media, it is used for various seals such as B. O-rings are used in contact with water / steam, cooling liquids as well as acids and alkalis. It has been shown that these properties are advantageously largely retained when it is compounded according to the invention. Commercially available EPDM rubbers have an ethylene content of 45-75% by weight. Polymers with a lower ethylene content (45-55% by weight) are amorphous and have the best low-temperature flexibility. With increasing ethylene content, the crystallinity increases (pure linear polyethylene is highly crystalline). An EPDM with a medium ethylene content (55-65% by weight) is partially crystalline. Terpolymers above 65 wt.% Ethylene have larger crystalline areas and therefore behave like thermoplastic elastomers.

Even in the non-crosslinked state, these have a high tear strength.

Alternatively or in addition to EPDM, the polypropylene-based

thermoplastic elastomer also contain an ethylene-propylene copolymer (abbreviation E / P) as the second phase. This is a copolymer made from ethene and propene is manufactured, its known areas of application being, for example, hot melt adhesives and sealants.

Due to the two-phase composition of the polypropylene-based used according to the invention as polyolefin - together with the polyamide

thermoplastic elastomer, the polyamide-polyolefin blend according to the invention is not just a binary but a ternary polymer alloy, that is to say a polyblend whose three constituents advantageously each have their own way

the desired "material made to measure".

As far as the compatibilizer is concerned, which contains as at least one first component a partially neutralized ionomer, which is a copolymer that contains ethylene and acrylic acid monomer units, three different types of crosslinking are known for copolymers that contain ethylene and acrylic acid monomer units: physical, ionic and covalent.

The radical copolymerization of ethylene and acrylic acid results in highly branched polymers. The carboxy groups cause very good adhesion to polar materials, while the polyethylene matrix adheres well to non-polar carrier materials. They can act to promote adhesion between the polypropylene of the TPE-O and the polyamide. Hydrogen bridges also form between the carboxy groups, which ensure good internal cohesion through physical cross-linking.

If ethylene-acrylic acid copolymers - as provided according to the invention - are then neutralized with metal ions, such as Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ or Zn ²⁺ , for crosslinking in the context of the second type of crosslinking, these groups accumulate ion clusters together, and ionic networks are formed. In the third type of crosslinking, covalently crosslinked ethylene-acrylate elastomers are obtained from ethylene-methyl acrylate-acrylic acid terpolymers which are chemically linked with diamines.

Blends in which mixed forms of the three types of crosslinking mentioned can be present are also advantageous according to the invention. Ionomers are obtained by copolymerization of a non-polar with a polar monomer, as in the case according to the invention from ethylene and acrylic acid monomer units (English abbreviation: EAA - Ethylene Acrylate Acid). The polar bonds push back the crystallization and lead to the aforementioned "ionic crosslinking". Compared to conventional thermoplastics, ionomers have the advantage that both secondary valence forces and ionic bonds are effective in them. These ion bonds are particularly strong and give the substance its characteristic properties. In addition, unlike most other plastics, they can also serve as electrolytes.

The compounded using such a compatibilizer

Polyblend according to the invention behaves like a thermoplastic elastomer, so that it is very suitable for pipe extrusion. This applies optimally when it is in the stated proportions in the range from 7.5 to 50 parts by weight based on 100 parts of the mixture of the polypropylene-based

thermoplastic elastomer and the polyamide is contained in the blend according to the invention.

In the context of the invention, the compatibilizer can advantageously be used as a second additional optional component, a terpolymer of ethylene, alkyl acrylate and glycidyl methacrylate, e.g. B. ethylene methacrylic glycidyl methacrylate (EnMaGma). The mass ratio of the first component of the compatibilizer to the second component of the compatibilizer can - if present - be in the range from 0.05 to 2.0, preferably in the range from 0.2 to 1.0. The crosslinking behavior achieved in this way preserves the positive properties of the ionomer, but advantageously lowers the high melting temperature occurring in the case of the ionomers mentioned, which - considered as a pure material for the ionomer - would be in the range of 290 ° C to 330 ° C, in the sense of a improved extrudability at lower processing temperatures.

As regards the polyamide as a blend component according to the invention, so are

Polyamides are an extremely large class of polymers, the individual representatives of which can be produced in different ways. The presence of functional amide groups —CO — NH— or also —CO — NR— in the macromolecule is characteristic, where R describes an organic, in particular aliphatic or also aromatic radical.

For the designation of the polyamides with abbreviations consisting of the letters "PA" followed by numbers and letters, reference is made to the standard DIN EN ISO 1043-1 (09/2016). According to this, polyamides, which are derived from an aminocarboxylic acid of the type H2N- (CH2) x-COOH or the corresponding

Lactams can be derived, marked with PA Z, where Z denotes the number of carbon atoms in the monomer (Z = x + 1). So stands z. B. PA 6 for a polymer made from e-caprolactam or w-aminocaproic acid [NH- (CH2) 5-CO] n, with n as the degree of polymerization. PA 11 is made from 11-aminoundecanoic acid and PA 12 from laurolactam or w-aminodecanoic acid.

PA 11 and PA 12 are cold-resistant down to at least -50 ° C and continuously heat-resistant up to +80 ° C. By adding stabilizers and plasticizers However, the resistance to cold or heat can be reduced to values of -60 ° C or

+110 ° C, briefly up to 160 ° C. The material has only a very low water absorption, with molded parts made from it showing only the slightest dimensional changes when the ambient humidity changes. Even well below freezing point PA 12 has an extraordinarily high impact strength and

Notched impact strength. In addition, it has good to very good chemical resistance to grease, oils, fuels, hydraulic fluids, many solvents, salt solutions and other chemicals.

Polyamides that can be derived from diamines and dicarboxylic acids of the types H2N- (CH2) x-NH2 and HOOC- (CH2) y-COOH are identified with PA Z1 Z2, where Z1 is the number of carbon atoms in the diamine and Z2 the number of Denotes carbon atoms in the dicarboxylic acid (Z1 = x, Z2 = y + 2). So stands z. B. PA 66 for the polymer of hexamethylenediamine (HMDA, 1, 6-diaminohexane) and adipic acid [NH- (CH2) 6-NH-CO- (CH2) 4-CO] n. PA 6 10 stands for the polymer made from HMDA and sebacic acid (decanedioic acid, 1,8-octanedicarboxylic acid, HOOC- (CH2) 8-COOH).

Particularly suitable polyamides for the blend according to the invention are long-chain polyamides in the mono- or dimer, such as PA 11, PA 12, PA 6 10, PA 6 12, PA 6 14, in which Z ³ 11 or Z2 ³ 10 ( at Z1 ³ 6).

In the polyamide-polyolefin blend according to the invention, a content of additives such as fillers, heat stabilizers, antioxidants, anti-aging agents, plasticizers or plasticizers, lubricants,

Lubricants and / or flow aids, can be provided, the additives in a range of 0.5 to 25 parts by weight, preferably 4 to 15 parts by weight, based on 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide. The blend according to the invention is in a tube, in particular in a

Cooling water pipe of an automobile, through the use of the cheaper one

polypropylene-based thermoplastic elastomer as a blend component with a reduced material wall compared to the use of pure PA12,

especially with regard to its properties of creep resistance, media resistance and flexibility, on a par or even superior to the known PA12 pipes.

A pipe according to the invention is characterized in that its wall is made using the thermoplastic polyamide-polyolefin blend according to the invention, in which the polyolefin is a polypropylene-based thermoplastic elastomer, which in a mass ratio in the range from 0.06 to 4.8 to the polyamide The compatibilizer is contained in a range from 7.5 to 50 parts by weight based on 100 parts of the mixture of the polypropylene and the polyamide and contains a partially neutralized ionomer which is a copolymer which contains ethylene and acrylic acid monomer units.

The pipe can advantageously be produced in particular by extrusion, but the polyblend according to the invention is also suitable for the production of other extrusion goods, such as corrugated pipes and profiles, etc.

The pipe wall can advantageously be designed in particular in one layer, but the production of a multi-layer pipe by, for example, coextrusion of one or more further layers lying radially inside and / or outside the layer consisting of the blend according to the invention is not excluded.

Further advantageous design features of the invention are contained in the dependent claims and the following description. In relation to the description that follows, it is expressly emphasized that the invention does not apply to the exemplary embodiment, nor does it apply to all or several of the features described in each case for the exemplary embodiment

Combinations of features is limited. Rather, each individual partial feature of the exemplary embodiment can also have an inventive significance in isolation from all other partial features described in connection therewith, either by itself or in combination with only a few other partial features. So can

For example, the branded products listed in Table 2 below can be replaced with alternative materials with the same or at least largely similar chemical structure with no or only marginal change in the minimum and maximum values of the percentages.

According to the procedure described below, on the one hand polyamide comparison pipes and on the other hand polyblend pipes according to the invention were produced.

The comparison pipes were made from VESTAMID® X7393. It is a standardized molding compound according to ISO 1874-PA12-HIP, EHL, 22-005, which is used as type PA 12-PHLY according to DIN 73 378 and DIN 74 324 for flexible pipes and hoses for the automotive industry. According to the above-mentioned ISO standard (including the measuring methods prescribed therein), the polymer has the properties listed in Table 1.

The polymer is supplied as granules and is one when processed

plasticized, highly viscous PA 12 molding compound with optimized low-temperature impact strength after solidification. It is especially for an extrusion of semi-hard Suitable for pipes with high burst pressure resistance. The recommended melt temperature for profile extrusion is 220 ° C to 250 ° C.

Table 1: Properties of PA12 (comparative example, VESTAMID® X7393)

The pipes according to the invention were produced on the basis of the polyblend formulation according to the invention according to the last column of Table 2, which is specified as preferred. The third and fourth columns of the table contain the minimum and maximum values of the preferred ranges. Table 2: Recipe according to the invention

Grilamid 2S, which can be obtained from EMS-Grivory, is PA 6 10 and, as already mentioned, is produced by the polycondensation of hexamethylenediamine and sebacic acid. Hexamethylenediamine is extracted from petroleum while

Sebacic acid is obtained from the organic raw material castor oil through a multi-stage chemical process. Polyamide 6 10 therefore advantageously consists of 62 percent renewable raw materials. Other special features of Grilamid 2S (PA 6 10) are its low water absorption and good properties

Dimensional stability compared to PA 6 or PA 66, its good chemical and weather resistance, its high melting point of 215 ° C and its

problem-free processability.

Vistamaxx ™ 6202 is offered as granules by Exxon Mobil and is a polypropylene-based thermoplastic elastomer with isotactic propylene Repeating units and statistical distribution of ethylene groups in the polyolefin copolymer. The ethylene content is 15 to 16% by mass.

In this context, it should be noted that within the scope of the invention - notwithstanding the above. usual compositions - in that

polypropylene-based thermoplastic elastomer an ethylene content of less than 40 mass% is considered optimal, in particular an ethylene content in the range of only 7 mass% to 25 mass%, preferably in the range of 12 mass% to 19 mass%. -%. Accordingly, the propylene content is higher than that of the known polypropylene-based thermoplastic elastomers described above.

Another special feature of Vistamaxx ™ 6202 is that it does not use the classic Ziegler-Natta catalysts, which have the disadvantage that they usually have to be used as heterogeneous catalysts on a carrier material because they are not soluble in organic solvents but is made with metallocene catalysts. Metallocenes are a group of organometallic compounds in which a central metal atom is sandwiched between two cyclopentadienyl ligands (C5H5, abbreviation: Cp). The metallocene catalyst is the

isotactic arrangement of the propylene repeat units, control of the molecular weight distribution and the degree of linearity or branching of the molecules - and thus later the crosslinking - made possible. As a result, in the polyblend according to the invention, the viscoelastic properties can advantageously be influenced in the sense of a reduced tendency to creep.

According to the manufacturer's specification, Vistamaxx ™ 6202 has the properties listed in Table 3. Table 3: Properties of Vistamaxx ™ 6202

For the determination methods, the respective versions of the standard that were valid on 01/01/2017 are to be used.

Typical properties of Lotader® AX 8900 are shown in Table 4 below.

Table 4: Properties of Lotader® AX 8900

Lotader® AX 8900 is a terpolymer with statistical distribution of its

Repeat units ethylene (68% by mass), acrylic ester (24% by mass) and

Glycidyl methacrylate (8 mass%). It is produced in high pressure autoclaves and sold by Arkema.

For the methods of determining the properties listed in Table 4, the respective versions of the standards that were valid in February 2018 are to be used. Table 4 also shows that European ISO standards lead to the same measurement results as the US ASTM standards. The acrylic ester constituents of Lotadei® AX 8900 (EnMaGma) cause partial molecular polarity in the blend according to the invention, reduce hardness and improve thermal stability during processing. As the acrylic ester content increases, the flexibility of the end product and its impact strength increases due to the associated decrease in crystallinity.

The glycidyl methacrylate causes a reactivity towards OH, COOH and NH2 groups, which during the mixing process in the melt with the polymers for which it is used as a compatibilizer, an optimally homogeneous

Distribution is achieved. Lotader® AX 8900 is not only compatible with LDPE, but advantageously also with ethylene-containing copolymers, such as the ethylene-containing TPE-O described above.

Aclyn® 295 is an ionomer from Honeywell, usually used in inks and coatings, which contains ethylene and acrylic acid monomer units and has the chemical formula (-CH2-CH2-COO-CH2-CH2-) xZn _y . It is 98 percent neutralized with zinc (y = 0.98x), and therefore essentially to be regarded as a salt. The use of Aclyn® 295 in the polyblend according to the invention has a positive effect on a high level of corrosion resistance, in particular to zinc chloride solutions.

Bruggoien® H333 is a heat stabilizing additive from the Brüggemann group of companies. Those sold under the brand name Bruggoien®

Heat stabilizers are used to prevent the phenomenon that occurs with many polymer materials, due to the influence of heat, light and

Atmospheric oxygen the physical properties and the appearance of the respective plastic can be changed considerably. A distinction is made between processing stabilizers, which primarily counteract polymer degradation in the melt phase - i.e. during compounding, injection molding or extrusion - and long-term stabilizers that are used during the use of the finished part high ambient temperatures (60 ° - 130 ° C) prevent polymer degradation, high temperature stabilizers, which are effective up to 180 ° C, as well as UV stabilizers, for effective protection of the finished parts against polymer degradation by UV radiation. Combinations of various heat-stabilizing additives can result in additional synergy effects. Specifically, the Bruggolens® H333 additive used is the active ingredient copper iodide, which stabilizes polyamides at temperatures of up to 180 ° C.

Irganox® 1098 is the trade name for benzene propanamide, N, N'-1, 6-hexanediyl- bis [3,5-bis (1, 1-dimethylethyl) -4-hydroxy. It is a sterically hindered phenolic compound. It is what is called a primary antioxidant

(Antioxidant I ”) and is manufactured by the company BASF in order to achieve increased thermal stability in polymers, in particular in polyamides, with its addition in particular causing discoloration of the polymer

can be avoided.

P-EPQ, which - as can be seen from Table 2 - in an inventive

Formulation as a so-called secondary, phosphorus-based antioxidant

(.Antioxidant II “) can be used, prevents a thermo-oxidative

Decomposition and yellowing during processing. It is a

Multi-component system with the CAS number 119345-01-6. Under this

The exact number of the Chemical Abstracts Service can also be found

chemical structure, the product names of various other suppliers and its properties.

The polysiloxane product Dow-Corning® is shown in Table 2 as a further additive

MB50-002 from Dow-Corning Corporation. These are pellets in which an ultra-high molecular weight (UHMW) polysiloxane is finely dispersed up to 50% by mass in a low-density polyethylene matrix (LDPE) is embedded. Ultra high molecular weight (UH MW) means that the mean molecular weight of the siloxane is above 300,000 g / mol and that the polysiloxane has a kinematic viscosity of above 5,000,000 - determined according to DIN 51562 (01/1999) at 40 ° C. By doing

Blend according to the invention, it improves the flowability and reduces the

Wall adhesion when shaping the polymer mass. The LDPE owns

due to its chemical similarity to Vistamaxx ™ 6202 (presence of

CH2 groups) - but especially under the effect of the

Compatibility Maker - a high level of compatibility with the

polypropylene-based thermoplastic elastomer of the formulation.

Table 2 lists Proviplast® 024 from the company as the last ingredient in the formulation

Proviron. It is a plasticizer that in particular

equally good for PA 6 10, PA 6 12, PA 10 10, PA 11 and PA 12 as

Plasticizer is replaceable. Proviplast® 024 is by its chemical nature a sulphonamide, namely N-butylbenzenesulphonamide.

It can be seen from Table 2 that the polypropylene-based thermoplastic elastomer in the preferred blend composition is in a mass ratio of 0.154 (10/65) to the polyamide. It is therefore in a preferred range from 0.1 to 3.0. According to the invention this should

Mass ratio at least in the range of 0.05 to 5.0.

The compatibility maker (sum of the first component and the second

Component 16 + 3 = 19) - based on 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide (65 + 10 = 75) - contains 25.3 parts (19/75) in the mixture. It is therefore in a preferred range of 12 to 30 parts by weight, based on 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide. The Compatibility agents should according to the invention at least in a range of 12 to 30 parts by weight, based on 100 parts of the mixture of the

polypropylene-based thermoplastic elastomer and the polyamide.

The mass ratio of the ionomer as the first component of the

Compatibility maker for the terpolymer made from ethylene, alkyl acrylate and

Glycidyl methacrylate as the second compatibilizer component is 0.187 (3/16). It is therefore in a preferred range from 0.2 to 1.0. The total of the additives is 6 mass%. Based on 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide (65 + 10 = 75) this is 8 parts by weight. The proportion is therefore in a preferred range of 4 to 15 parts by weight, based on 100 parts of the mixture of the

polypropylene-based thermoplastic elastomer and the polyamide. According to the invention, the mass ratio should be at least in the range from 0.05 to 2.0.

The compound was produced in a twin screw extruder with a screw diameter of 25 mm. The constituents introduced in the solid state were melted and in one

Treated temperature in the cylinder of 250 ° C until the establishment of a homogeneous melt.

The pipes were produced in an extruder with a screw diameter of 45 mm. A barrier screw with a ratio of length L to diameter D of 25 was used. Characteristic of a

The barrier screw is that in the plasticizing zone an additionally inserted web, the so-called barrier web, separates the solids from the melt. The freshly melted material can be transferred from the solids channel via the barrier web into the Melt channel flow while the barrier gap is dimensioned so that the solid is retained. This ensures a well-digested melt and prevents unmelted solid particles from escaping from the plasticizing zone. The temperatures in the extruder were as follows: feed zone - 240 ° C, compression zone - 245 ° C, discharge zone - 250 ° C, extrusion head - 250 ° C. The geometry of the comparison tubes and the

Pipes according to the invention could equally be described by the specification 4.05 × 1 mm.

Tables 5 and 6 contain representations of the tensile tests on the pipes using the ZWICK ROELL Z020 in accordance with the DIN EN ISO 527-2: 2012-06 standard

Test results obtained, Table 5 referring to the values before a

Heat aging and Table 6 refer to the values thereafter.

Table 5: Mechanical pipe properties

Table 6: Mechanical pipe properties after heat aging for 72 h at 130 ° C and percentage change compared to the unaged pipe

With approximately the same tensile modulus, the tube according to the invention contains fewer volatile components than the comparison tube, as can be seen from the weight loss during heat aging, which indicates that the low tensile modulus in

Comparative material is achieved via plasticizers. Overall, due to the increase in tensile strength and the decrease in elongation at break after

Heat aging that the pipe according to the invention from the mechanical

Properties has a high suitability for use as a cooling water pipe in an automobile.

In addition, there is a high level of media resistance, in particular to cooling water and aqueous zinc chloride solutions. The

The blend according to the invention has good processability by extrusion, with the ability to assemble pipes according to the invention on mandrels as pipe connector elements is ensured. In making more durable

Mandrel connections in fluid-carrying pipe systems show - at lower costs and high material availability - a similar expansion and creep behavior as that of PA 12. The polymer blend according to the invention advantageously has an optimal combination of the material properties of long-chain polyamides as technical ones

Plastics, in particular with similar creep resistance, media resistance and flexibility as PA 12, with a high media resistance and low-cost (inexpensive) production as well as the easy availability of polyolefins as mass-produced plastics.

The person skilled in the art can also supplement the invention with further expedient technical embodiments without departing from the scope of

Invention is abandoned. So z. B. the known methods for

Optimization of the ratio of the requirement profile to the manufacturing effort by material variation in sequentially successive sections of the pipeline or in the radial direction in successive layers in the pipe wall can be used combinatorially.

Thermoplastic plastic pipes according to the invention have in particular an excellent ability for crack-free and creep-free assembly on one

A mandrel as a pipe connector element as well as optimally high media resistance, in particular - under the aspect of use as cooling water pipes - high hydrolysis resistance and zinc chloride resistance according to SAE J 2240. They are therefore particularly suitable for use as cooling water pipes in an automobile.

Furthermore, the invention has not yet been restricted to the combinations of features defined in the independent claims, but can also be defined by any other combination of specific features of all of the individual features disclosed. This means that in principle practically every single feature of the independent claims can be omitted or replaced by at least one individual feature disclosed elsewhere in the application.

Claims

Expectations

1. Thermoplastic polyamide-polyolefin blend, in particular for the extrusion of pipes intended for fluid guidance, containing at least one

Polyolefin, a polyamide and a compatibilizer,

characterized in that the polyolefin is a polypropylene-based thermoplastic elastomer which is in a mass ratio im

Range from 0.05 to 5.0 for the polyamide, the

Compatibility agent in a range from 7.5 to 50 parts by weight, based on 100 parts of the mixture of the polypropylene-based

thermoplastic elastomer and the polyamide, and wherein the compatibilizer contains as at least a first component a partially neutralized ionomer which is a copolymer which contains ethylene and acrylic acid monomer units.

2. polyamide-polyolefin blend according to claim 1,

characterized in that the polypropylene-based

thermoplastic elastomer in a mass ratio in the range from 0.1 to 3.0 to the polyamide.

3. polyamide-polyolefin blend according to claim 1 or 2,

characterized in that the compatibilizer is contained in a range of 12 to 30 parts by weight, based on 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide.

4. Polyamide-polyolefin blend according to one of claims 1 to 3, characterized in that the polypropylene-based

thermoplastic elastomer a polymer blend with one in one

polypropylene-containing matrix dispersed, in particular uncrosslinked, phase of ethylene-propylene-diene rubber and / or ethylene-propylene copolymer.

5. polyamide-polyolefin blend according to one of claims 1 to 4,

characterized in that the polypropylene-based

thermoplastic elastomer has an ethylene content of less than 40 mass%, in particular an ethylene content in the range from 7 mass% to 25 mass%, preferably in the range from 12 mass% to 19 mass%.

6. polyamide-polyolefin blend according to one of claims 1 to 5,

characterized in that the polypropylene-based

thermoplastic elastomer is made with metallocene catalysts.

7. polyamide-polyolefin blend according to one of claims 1 to 6,

characterized in that the partially neutralized ionomer of the first component of the compatibilizer is 80 percent to 99 percent, preferably 92 percent to 98 percent, with metal ions such as Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ or in particular Zn ²⁺ , is partially neutralized.

8. polyamide-polyolefin blend according to one of claims 1 to 7,

characterized in that the compatibilizer is a second component of a terpolymer of ethylene, alkyl acrylate and

Contains glycidyl methacrylate.

9. polyamide-polyolefin blend according to one of claims 1 to 8, characterized in that a mass ratio of the first component of the compatibility maker to a / the second component of the

Compatibility maker in the range from 0.05 to 2.0, preferably im

Range from 0.2 to 1.0.

10. polyamide-polyolefin blend according to one of claims 1 to 9,

characterized in that the polyamide according to DIN EN ISO 1043-1 is described as PA Z or PA Z1 Z2, where Z ³ 11 or Z1 ³ 6 and Z2> 10.

11. polyamide-polyolefin blend according to one of claims 1 to 10,

characterized by a content of additives such as fillers,

Heat stabilizers, anti-aging agents, antioxidants, plasticizers and / or flow aids, the additives being contained in a range from 0.5 to 25 parts by weight, preferably 4 to 15 parts by weight, based on 100 parts of the mixture of the polypropylene-based thermoplastic elastomer and the polyamide.

12. Thermoplastic plastic pipe whose Rohnwandung at least partially consists of a polyamide-polyolefin blend according to one of claims 1 to 11.

13. Plastic pipe according to claim 12,

characterized in that the pipe wall has a single-layer design and consists entirely of a polyamide-polyolefin blend according to one of claims 1 to 11.

14. Connection comprising a thermoplastic plastic pipe according to claim 12 or 13 and a mandrel as a pipe connector element.

15. Use of a thermoplastic plastic pipe according to claim 12 or 13 as a cooling water pipe in an automobile.