Fibre reinforced polyamide moulding compound

Abstract

The present invention relates to a polyamide moulding compound consisting of A 33-79.4 wt% of a polymer mixture consisting of wherein the sum of A1 and A2 is 100 wt% of A; A1 55 to 85 wt% of at least one semi-crystalline, aliphatic polyamide selected from the group PA 6, PA 46, PA 56, PA 66, PA 66/6, PA 610, PA 612, PA 6/12, PA 1010, PA 11, PA 12, PA 1012, PA 1212 and mixtures thereof; A2 15 to 45 wt% of at least one semi-aromatic polyamide selected from the group PA 6l, PA 5l/5T, PA 6l/6T, PA 10l/10T, PA 10T/6T, PA 6T/BACT/66/BAC6, PA MXD6, PA MXD6/MXDl and mixtures thereof; B 20 to 60 wt% of a reinforcing fibre; C 0.6 to 2.0 wt% metal borate, wherein the molar ratio of metal to boron is in the range from 0.5 to 4; D 0 to 5.0 wt% additives, different from A, B and C; wherein the sum of the components A to D is 100 wt% and wherein the moulding compound comprises neither copper halides nor metal phosphinates.

Claims

1. A polyamide moulding compound consisting of A 33-79.4 wt% of a polymer mixture consisting of A1 55 to 85 wt% of at least one semi-crystalline, aliphatic polyamide selected from the group PA 6, PA 46, PA 56, PA 66, PA 66/6, PA 610, PA 612, PA 6/12, PA 1010, PA 11, PA 12, PA 1012, PA 1212 and mixtures thereof; A2 15 to 45 wt% of at least one semi-aromatic polyamide selected from the group PA 6I, PA 5I/5T, PA 6I/6T, PA 10I/10T, PA 10T/6T, PA 6T/BACT/66/BAC6, PA MXD6, PA MXD6/MXDI and mixtures thereof; wherein the sum of A1 and A2 is 100 wt% of A; B 20 to 60 wt% of a reinforcing fibre; C 0.6 to 2.0 wt% metal borate, wherein the molar ratio of metal to boron is in the range from 0.5 to 4; D 0 to 5.0 wt% additives, different from A, B and C; wherein the sum of the components A to D is 100 wt% and wherein the moulding compound comprises neither copper halides nor metal phosphinates.

2. The polyamide moulding compound according to claim 1, characterised in that the proportion of component A is in the range from 40.4 to 74.4 wt%, preferably in the range from 46.6 to 69.25 wt%, in each case with respect to sum of components A to D; and/or the proportion of component A1 is in the range from 60 to 85 wt%, preferably in the range from 65 to 80 wt%, and the proportion of component A2 is in the range from 15 to 40 wt%, preferably in the range from 20 to 35 wt%, in each case with respect to the sum of components A1 and A2; and/or the proportion of component B is in the range from 25 to 55 wt%, preferably in the range from 30 to 50 wt%, in each case with respect to the sum of components A to D; and/or the proportion of component C is in the range from 0.6 to 1.6 wt%, preferably in the range from 0.7 to 1.4 wt%, in each case with respect to the sum of components A to D; and/or the proportion of component D is in the range from 0 to 3.0 wt%, preferably in the range from 0.05 to 2.0 wt%.

3. The polyamide moulding compound according to claim 1, characterised in that the polyamide A1 is selected from PA6, PA 56, PA 66, PA 66/6, PA 610 and mixtures thereof; and/or the polyamide A2 is selected from PA 6I/6T, PA 6T/BACT/66/BAC6 and a mixture thereof.

4. The polyamide moulding compound according to claim 1, characterised in that the component A2 is selected from an amorphous, semi-aromatic polyamide PA 6I/6T with 55 to 85 mol% hexamethylene isophthalamide units and 15 to 45 mol% hexamethylene terephthalamide units and/or a semi-crystalline, semi-aromatic polyamide PA 6T/BACT/66/BAC6 with 55 to 70 mol% hexamethylene terephthalamide units, 20 to 25 mol% 1,3-bis(aminomethyl)-cyclohexane terephthalamide units, 6 to 16 mol% hexamethylene adipamide units and 2 to 4 mol% 1,3-bis(aminomethyl)cyclohexane adipamide units.

5. The polyamide moulding compound according to claim 1, characterised in that the reinforcing fibre B is a glass fibre; and/or is selected from the group consisting of E-glass fibres, ECR-glass fibres, D-glass fibres, L-glass fibres, S-glass fibres and/or R-glass fibres; and/or a long glass fibre (continuous glass fibre, roving); and/or has a diameter in the range from 10 to 20 .Math.m, preferably in the range from 12 to 17 .Math.m.

6. The polyamide moulding compound according to claim 1, characterised in that the heat distortion temperature HDT-C according to ISO 75:2013 is at least 120° C., preferably at least 130° C., in particularly preferably at least 200° C.; and/or the heat distortion temperature HDT-A according to ISO 75:2013 is at least 200° C., preferably at least 230° C.

7. The polyamide moulding compound according to claim 1, characterised in that the metal borate C is selected from the group consisting of: sodium borate, in particular borax pentahydrate Na2O.Math.2B2O3.Math.5H2O, borax decahydrate Na2O.Math.2B2O3.Math.10H2O, water-free borax Na2O.Math.2B2O3 and disodium octaborate tetrahydrate Na2O.Math.4B2O3.Math.4H2O, magnesium borate 2MgO.Math.B2O3, calcium borate 2CaO.Math.3B2O3.Math.5H2O, calcium metaborate CaO.Math.B2O3.Math.4H2O, magnesium calcium borate, e.g., hydroboracite CaMg[B3O4(OH)3]2.Math.3H2O, barium metaborate (BaO.Math.B2O3.Math.H2O), zinc borate xZnO.Math.yB2O3.Math.zH2O, for example 2ZnO.Math.3B2O3.Math.7H2O, 2ZnO.Math.3B2O3.Math.3.5H2O, 2ZnO.Math.2B2O3.Math.3H2O, 4ZnO.Math.B2O3.Math.H2O, 2ZnO.Math.3B2O3, calcium silicate borate, sodium silicate borate, aluminium silicate borate, aluminium borate, copper borate, iron borate.

8. The polyamide moulding compound according to claim 1, characterised in that the metal borate C selected is a zinc borate compound with a boron:metal ratio of 1 to 3, preferably 3.

9. The polyamide moulding compound according to claim 1, characterised in that the component D is selected from the following group: UV stabilisers, heat stabilisers, which are free of copper halides, radical scavengers, processing aids, inclusion inhibitors, lubricants, mould release aids, crystallisation accelerators or retardants, flow promoters, lubricants, mould release agents, pigments, dyes and marking substances, optical brighteners, processing agents, antistatic agents, carbon black, graphite, carbon nanotubes.

10. The polyamide moulding compound according to claim 1, characterised in that component D is selected from UV stabilisers, heat stabilisers, zinc oxide, zinc sulphide, zinc stearate, zinc montanate, calcium montanate, calcium stearate, aluminium stearate and mixtures thereof.

11. The polyamide moulding compound according to claim 1, characterised in that the moulding compound consists of the following components: A: 46.6-69.25 wt% of a polymer mixture, consisting of A1 65 to 80 wt% polyamide PA6, PA 66, PA 610 and mixtures thereof; A2 20 to 35 wt% polyamide PA 6I/6T, PA 6T/BACT/66/BAC6 and mixtures thereof; wherein the sum of A1 and A2 is 100 wt% of A; B: 30-50 wt% long glass fibres (continuous glass fibres, rovings); C: 0.7-1.4 wt% zinc borate with a boron:metal ratio of 0.5 to 4; D: 0.05-2.0 wt% additive, different from A, B and C; wherein the sum A to D is 100 wt% and wherein the moulding compound comprises neither copper halides nor metal phosphinates.

12. A moulded body made from a polyamide moulding compound according to claim 1 or having at least one region or a coating made from a polyamide moulding compound according to one of the preceding claims, preferably produced by injection moulding, extrusion or blow moulding, wherein it is preferably a moulded body in the field of housings, covers or frames, a housing or a housing component, preferably housings or housing parts for portable electronic devices, claddings or covers, domestic devices, domestic appliances, spectacle mounting, spectacle frames, sunglasses, cameras, spy glasses, decorative items, devices and apparatuses for telecommunications and consumer electronics, interior and exterior parts in the automotive sector and in the field of other transport means, interior and exterior parts, preferably with support or mechanical function in the field of electronics, furniture, sports, mechanical engineering, sanitation and hygiene, fans, in particular a fan rotor or fan wheel, medicine, energy and drive technology, particularly preferably mobile phones, smartphones, organisers, laptop computers, notebook computers, tablet computers, radios, cameras, watches, calculators, sensor housings, measurement devices, players for music and/or video, navigation devices, GPS devices, electronic picture frames, external hard drives and other electronic storage media.

13. The moulded body according to claim 12, characterized in that the requirements for fungicidal surfaces according to method A of DIN EN ISO 846:2020 are met and the test according to the method described in Annex C gives the classification “ZERO” or “ONE A” or “ONE”; and/or the resistance to bacteria according to method C of DIN EN ISO 846: 2020 is met and the test according to the method described in Annex C gives the classification “ZERO” or “ONE”.

14. A use of a polyamide moulding compound according to claim 1 for producing mould-resistant and bacteria-resistant moulded bodies, in particular for door handles, hands-free door openers, handrails, kitchen appliances, medical devices, automotive interior functional parts, steering wheels with levers and buttons, gearsticks, control units for air-conditioning systems, control units for entertainment devices, door locking systems, hinges, handles, grab handles and bars in public transport, medical care beds, hospital furniture, knobs and control elements in lifts, kitchen furniture, bathroom furniture and accessories, housings and covers, ventilation systems, fans, axial fans, centrifugal fans, process fan rotors.

Description

[0054] In a preferred embodiment, in addition to the above named stabilisers, component D also contains the following compounds selected from the group consisting of zinc oxide, zinc sulphide, zinc stearate, zinc montanate, calcium montanate, calcium stearate, aluminium stearate and mixtures thereof. Furthermore, it is preferred if these compounds are present in the moulding compound at 0.05 to 0.5 wt%, with respect to the components A to D.

[0055] Experiments have also shown that, in particular, a polyamide moulding compound which consists of the following components, has superior properties: [0056] A: 46.6-69.25 wt% of a polymer mixture, consisting of [0057] A1 65 to 80 wt% polyamide PA6, PA 66 or PA 610 and mixtures thereof; [0058] A2 20 to 35 wt% polyamide PA 6l/6T, PA 6T/BACT/66/BAC6 and mixtures thereof; [0059] wherein the sum of A1 and A2 is 100 wt% of A; [0060] B: 30-50 wt% long glass fibres (continuous glass fibres, rovings); [0061] C: 0.7-1.4 wt% zinc borate with a B:M ratio of 0.5 to 4; [0062] D: 0.05-2.0 wt% additive, different from A, B and C; wherein the sum A to D is 100 wt% and wherein the moulding compound comprises neither copper halides nor metal phosphinates.

[0063] Surprisingly, it has been found that if the filled polyamide moulding compounds according to the invention are processed into moulded bodies, moulded bodies are obtained which have above-average properties, in particular in relation to notched impact strength, tensile strength at break, elongation at break, the heat distortion temperature and resistance to moulds and/or bacteria. In addition, it was surprisingly found that the addition of metal borates in combination with the preferably used long glass fibres (continuous glass fibres) has practically no negative effects on the mechanical properties of the moulding compound or of the moulded body. On the other hand, when so-called cut or short glass fibres are used, disadvantages in terms of the mechanical properties, in particular the notched impact strength, tensile strength at break and elongation at break must be tolerated.

[0064] It is clear that the long glass fibres (continuous fibres, rovings) that are preferably used according to the invention form a web or skeleton (fibre agglomerate) in the moulded body by wooling of the fibre fragments formed during the production of the moulded body, which effectively prevents crack propagation and thus contributes to shape retention at higher temperatures as well as to the notched impact strength and thus enables the excellent properties despite the presence of a pigment-like additive such as the metal borate.

[0065] The pronounced wooling of the long glass fibres in the moulded body is reinforced by the fact that the long glass fibres are less severely damaged during injection moulding. The preferably low-viscosity polyamide matrix in particular contributes to this. Therefore, even under unfavourable conditions, such as high shear during injection moulding in the production of a moulded part, it is ensured that the fibre fragments in the moulded body have a sufficient average length and length distribution that leads to a pronounced three-dimensional fibre agglomeration and thus to outstanding properties.

[0066] In the case of the moulding compounds reinforced with long glass fibres (continuous fibres, rovings) and the moulded bodies produced therefrom, it is particularly noteworthy that the notched impact strength at 23° C. remains substantially unchanged and constant due to the addition of metal borate, i.e., practically identical to the metal-borate-free moulding compound. On the other hand, when short glass fibres are used, the notched impact strength at 23° C. is reduced by up to 40% with respect to the metal-borate-free moulding compound, through the addition of metal borate. A similar behaviour can be observed with regard to the elongation at break. Here too, the preferably used long glass fibres show clear advantages.

[0067] Uncoated fillers, such as finely ground metal borates act as nucleating agents for semi-crystalline polyamides, i.e., they increase the crystallisation temperature and accelerate crystallisation. This is often accompanied by undesired embrittlement of fibre reinforced thermoplastics. Through suitable selection of the matrix components, such as the combination of a semi-crystalline, aliphatic polyamide A1 with an amorphous, semi-aromatic polyamide A2, the nucleating effect of the metal borate can be compensated.

[0068] The polyamide moulding compounds according to the invention have a heat distortion temperature HDT-C according to ISO 75:2013 of at least 120° C., preferably at least 130° C. and particularly preferably at least 200° C.

[0069] The polyamide moulding compounds according to the invention have a heat distortion temperature HDT-A according to ISO 75:2013 of at least 200° C., preferably at least 230° C.

[0070] The invention also relates to moulded bodies made from the described polyamide moulding compound or moulded bodies having at least one region or a coating made from a polyamide moulding compound, preferably produced by injection moulding, extrusion or blow moulding, which is preferably a moulded body in the following fields: housings, covers or frames, a housing or a housing component, preferably housings or housing parts for portable electronic devices, claddings or covers, domestic devices, domestic appliances, spectacle mountings, spectacle frames, sunglasses, cameras, spy glasses, decorative items, devices and apparatuses for telecommunications and consumer electronics, interior and exterior parts in the automotive sector and in the field of other transport means, interior and exterior parts, preferably with support or mechanical function in the field of electronics, furniture, sports, mechanical engineering, sanitation and hygiene, fans, in particular a fan rotor or a fan wheel, medicine, energy and drive technology, particularly preferably mobile phones, smartphones, organisers, laptop computers, notebook computers, tablet computers, radios, cameras, watches, calculators, sensor housings, measurement devices, players for music and/or video, navigation devices, GPS devices, electronic picture frames, external hard drives and other electronic storage media.

[0071] The moulded bodies preferably meet the requirements for fungicidal surfaces according to method A of DIN EN ISO 846:2020 and the test according to the method described in Annex C preferably gives the classification “ZERO” (0) or “ONE A” (1a). Additionally or alternatively, the moulded bodies meet the requirements for resistance to bacteria according to method C of DIN EN ISO 846: 2020 and the test according to the method described in annex C preferably gives the classification “ZERO” (0).

[0072] The invention also relates to the use of the described polyamide moulding compound for producing mould-resistant and bacteria-resistant moulded bodies, in particular for door handles, hands-free door openers, handrails, kitchen appliances, medical devices, automotive interior functional parts, steering wheels with levers and buttons, gearsticks, control units for air-conditioning systems, control units for entertainment devices, door locking systems, hinges, handles, grab handles and bars in public transport, medical care beds, hospital furniture, knobs and control elements in lifts, kitchen furniture, bathroom furniture and accessories, housings and covers, ventilation systems, fans, axial fans, centrifugal fans, process fan rotors.

[0073] The invention will be explained in greater detail by way of the following example. The following materials were used in the examples and comparative examples:

TABLE-US-00001 PA-1: polyamide-66 with η.sub.rel = 1.82, Tm = 262° C., RADICI, IT PA-2: polyamide-6 with η.sub.rel = 1.80, Tm = 222° C., BASF, DE APA-1: polyamide 6l/6T (67:33) with η.sub.rel = 1.50, Tg = 125° C., EMS-CHEMIE AG, CH APA-2: polyamide 6T/BACT/66/BAC6 (68.5/23.5/6/2) with η.sub.rel = 1.65, Tm = 325° C., Tg = 150° C., EMS-CHEMIE AG, CH LGF-1: E-glass roving NEG TufRov 4510-17-2400, round cross-sectional area with diameter 17 .Math.m, sizing system with aminosilane-based adhesion promoter and epoxy resin-based film former. LGF-2: E-glass roving NEG TufRov 4510-12-1200, round cross-sectional area with diameter 12 .Math.m, sizing system with aminosilane-based adhesion promoter and epoxy resin-based film former. GF: ECR-glass short fibre bundle, Vetrotex 995 EC10-4.5, length: 4.5 mm, filament diameter: 10 .Math.m, Saint-Gobain Vetrotex, FR Metal borate: Firebrake 500, (ZnO).sub.2(B.sub.2O.sub.3).sub.3, M:B = 3, U.S. Borax, USA Stabiliser: mixture of Irganox 1098 (BASF, DE) and Brüggolen H10 (Brüggemann, DE) in the ratio 2:1 Zinc sulphide: Sachtolith HD-S, ZnS, Huntsman, USA

[0074] The moulding compounds of the compositions B7 to B10, B12 and B13 in Table 2 were produced on a twin-screw extruder from Werner and Pfleiderer, model ZSK 30. The granules of components A1 and A2 and additives C and D were metered into the feed zone. The glass fibres (GF, short glass fibres) were metered into the polymer melt via a side feeder 3 housing units in front of the nozzle. The housing temperature was set as a rising profile from 270 to 300° C. A throughput of 10 kg was achieved at 150 to 200 rpm. The granulation was carried out by means of underwater granulation or hot cutting under water, in which the polymer melt is pressed through a perforated die and granulated by a rotating knife in a water stream immediately after exiting the die. After granulation and drying at 110° C. for 24 hours, the granule properties were measured and the test specimens produced.

[0075] The continuously reinforced compositions B1 to B6 (Table 1) and B11 (Table 2) were produced by a pultrusion method, in which the polymer mixtures A with additives C and/or D were mixed and melted in a twin-screw extruder, before being transferred into an impregnation unit and brought into contact with the preheated continuous filament glass fibres (LGF-1 and LGF-2, continuous glass fibres). More specifically, the pultrusion process proceeded as follows: The components A1, A2, C and D were metered into the feed zone of a twin-screw extruder with a screw diameter of 40 mm. The components were then mixed with a rising temperature profile from 270 to 340° C. The extruder, which is securely connected to the impregnation unit, conveys the melt directly into the impregnation unit, so that the glass fibres, which are preheated to 180 to 220° C., are infiltrated. The continuous glass fibres, 1200 tex rovings in the case of 12 .Math.m fibres and 2400 tex rovings in the case of 17 .Math.m fibres, are drawn at a speed of 8 to 15 metres per minute through the impregnating zone, with heating zones in the range from 340 to 400° C. After cooling in water, the thus-impregnated strands were cut to a length of 10 mm. After pelletisation and drying for 24 hours at 110° C., the properties of the pellets were measured and the test specimens produced.

[0076] The test specimens were produced on an Arburg injection moulding system, wherein cylinder temperatures of 260° C. to 300° C. and a peripheral screw speed of 15 m/min were set. A mould temperature of 100-140° C. was selected.

[0077] The measurements were carried out according to the following standards and on the following specimens.

Tensile Modulus of Elasticity

[0078] The tensile modulus of elasticity was determined in accordance with ISO 527 (2012) at 23° C. with a draw speed of 1 mm/min on an ISO tensile rod (type A1, mass 170 × 20/10 × 4) according to the standard: ISO/CD 3167 (2003).

Tensile Stress at Break and Elongation at Break

[0079] The tensile stress at break and elongation at break were determined in accordance with ISO 527 (2012) at 23° C. with a draw speed of 5 mm/min on an ISO tensile rod type A1 (mass 170 × 20/10 x 4 mm) according to the standard: ISO/CD 3167 (2003).

Impact Strength According to Charpy

[0080] The Charpy impact strength was determined in accordance with ISO 179/2*eU (1997,* 2 = instrumented) at 23° C. on an ISO test rod, type B1 (dimensions 80 × 10 × 4 mm), produced in accordance with the ISO/CD 3167 (2003).

Notch Impact Strength According to Charpy

[0081] The Charpy notch impact strength was determined in accordance with ISO 179/2*eA (1997,* 2 = instrumented) at 23° C. on an ISO test rod, type B1 (dimensions 80 × 10 × 4 mm), produced in accordance with the ISO/CD 3167 (2003).

Melting Point (T.SUB.m.) and melting enthalpy (ΔH.SUB.m.)

[0082] The melting point and melting enthalpy were determined on granules according to DIN EN ISO 11357-3: 2018. The DSC (differential scanning calorimetry) measurements were carried out with a heating rate of 20 K/min.

Glass Transition Temperature, T.SUB.g

[0083] The glass transition temperature T.sub.g was determined in accordance with DIN EN ISO 11357-2:2020 on granules by means of differential scanning calorimetry (DSC). This was carried out for each of the two heatings at a heating rate of 20 K/min. After the first heating, the sample was quenched in dry ice. The glass transition temperature (T.sub.g) was determined during the second heating. The midpoint of the glass transition area, which was given as the glass transition temperature, was determined by the “Half Height” method.

Relative Viscosity, Η.SUB.rel

[0084] The relative viscosity was determined according to ISO 307 (2007) at 20° C. For this purpose, 0.5 g of polymer granules were weighed into 100 ml of m-cresol, and the calculation of the relative viscosity (η.sub.rel) according to η.sub.rel = t/t.sub.0 was with respect to Section 11 of the standard.

Heat Deflection Temperature (HDT)

[0085] The heat deflection temperature or also called the deformation temperature under load (HDT) is reported as HDT/A and/or HDT/C. HDT/A corresponds to method A with a flexural stress of 1.80 MPa and HDT/C corresponds to method C with a flexural stress of 8.00 MPa. The HDT values were determined in accordance with ISO 75 (2013) on ISO impact bars measuring 80 × 10 × 4 mm.

Determination of the Actions of Microorganisms on Plastics

[0086] The resistance to moulds and bacteria was determined according to methods A and C of DIN EN ISO 846:2020 using plates with dimensions 50 × 50 × 2 mm. The evaluation was carried out using the method described in Annex C.

[0087] Unless otherwise noted in the tables, the test specimens were used to determine the mechanical properties in the dry state. For this purpose, the test specimens were stored in a dry environment at room temperature for at least 48 hours after injection moulding.

TABLE-US-00002 Composition and properties of the examples B1 to B6 Example Units B1 B2 B3 B4 B5 B6 Composition PA-1 (component A1) wt% 44.1 43.8 36.75 36.75 44.1 36.75 APA-1 (component A2) wt% 14.7 14.6 12.25 12.25 APA-2 (component A2) wt% 14.7 12.25 LGF-1 (component B) wt% 40.0 40.0 50.0 40.0 LGF-2 (component B) wt% 50.0 50.0 GF (component B) wt% Metal borates (component C) wt% 0.90 1.30 0.75 0.75 0.90 0.75 Stabiliser (component D) wt% 0.30 0.30 0.25 0.25 0.30 0.25 Properties HDT A °C 255 254 255 255 253 258 HDT C °C 208 208 217 218 210 220 Tensile modulus of elasticity MPa 14100 14100 17400 17600 14500 17800 Tensile stress at break MPa 238 235 268 288 242 290 Elongation at break wt.% 2.5 2.4 2.5 2.6 2.5 2.4 Impact strength Charpy, 23° C. kJ/m.sup.2 84 82 100 110 105 110 Notch impact strength Charpy, 23° C. kJ/m.sup.2 30 29 33 38 45 42 Resistance to moulds (ISO 846, method A) 1a 0 1a 1a 1a 1a Resistance to bacteria (ISO 846, method C) 0 0 0 0 0 0

[0088] The moulding compounds according to the invention of examples B1-B8 show good to very good resistance to moulds and bacteria and therefore clear advantages compared to the comparative examples B9 to B13. Example B11 shows that the selected metal borate concentration is too low to achieve a sufficient resistance to mould. A comparison of examples B9 and B10 with examples B1 to B4 shows that the preferably used continuous glass fibres have advantages with respect to the heat distortion temperature HDT-C, tensile strength at break, elongation at break and notched impact strength. On the other hand, the resistance to mould and bacteria is at the same high level as examples B1, B2 and B4.

TABLE-US-00003 Composition and properties of examples B7 and B8 and of comparative examples B9 to B13 Example Units B7 B8 B9 B10 B11 B12 B13 Composition PA-1 (component A1) wt% 44.1 36.75 44.8 37.3 44.4 44.8 PA-2 (component A1) wt% 68.5 APA-1 (component A2) wt% 14.7 12.25 14.9 12.4 14.8 14.9 LGF-1 (component B) wt% 40.0 LGF-2 (component B) wt% GF (component B) wt% 40.0 50.0 40.0 50.0 40.0 30.0 Metal borates (component C) wt% 0.90 0.75 0.50 1.00 Stabiliser (component D) wt% 0.30 0.25 0.30 0.25 0.30 0.25 0.50 Zinc sulphide (component D) wt% 0.05 Properties HDT A °C 235 235 235 235 255 237 205 HDT C °C 142 160 145 165 210 148 135 Tensile modulus of elasticity MPa 14000 18200 14000 18000 14000 14100 9500 Tensile stress at break MPa 205 211 230 250 240 232 185 Elongation at break wt.% 2.1 1.9 3.0 2.5 2.5 3.0 4.2 Impact strength Charpy, 23° C. kJ/m.sup.2 70 74 90 90 85 88 85 Notch impact strength Charpy, 23° C. kJ/m.sup.2 8 10 14 17 30 13 12 Resistance to moulds (ISO 846, method A) 1a 1a 4 4 2 3 3 Resistance to bacteria (ISO 846, method C) 0 0 0 0 0 1 1

[0089] In order to assess mould growth, a grid with 100 equal-size squares was placed on the incubator sample plates with dimensions 50 × 50 × 2 mm, and the squares which showed growth were counted, the 36 squares at the edge not being included in the evaluation. Based on the number of squares with mould growth that are visible to the naked eye or a microscope, the following score was determined: [0090] 0: None of the inner squares show mould growth that can be detected under the microscope at 50x magnification [0091] 1a: 1 to 16 squares show traces of mould growth under the microscope at 50x magnification [0092] 2: 1 to 16 squares have mould growth when observed with the naked eye [0093] 3: 17 to 32 squares have mould growth when observed with the naked eye [0094] 4: 33 to 64 squares have mould growth when observed with the naked eye

[0095] The assessment of the incubated sample plates with regard to resistance to bacteria was carried out analogously to the mould test, wherein squares with bacterial growth visible to the naked eye were counted: [0096] 0: The inner squares are free of bacterial growth [0097] 1: 1 to 16 squares show traces of bacterial growth