POLYAMIDE MOULDING COMPOSITIONS FOR GLASS COMPOSITES

Abstract

Thermoplastic polyamide moulding composition consisting of: (A) 30-99.9 percent by weight of at least one polyamide selected from the group consisting of: at least one aliphatic or semiaromatic polyamide, in each case with C:N ratio at least 8; at least one aliphatic or semiaromatic polyamide composed of at least one dicarboxylic acid and of at least one diamine and also optionally a proportion below 50 mol percent based on the entirety of dicarboxylic acids and diamine as 100 mol percent, of lactams and/or aminocarboxylic acids; and mixtures thereof; (B) 0.1-5.0 percent by weight of polyethyleneimine (PEI) or copolymers or derivatives thereof; (C) 0-60 percent by weight of fillers and/or reinforcing materials; (D) 0-5.0 percent by weight of additives; where the entirety of (A)-(D) provides 100% of the thermoplastic polyamide moulding composition, and also uses of such moulding compositions in particular in the context of components bonded to mineral glass.

Claims

1. A composite comprising at least three directly mutually adjoining layers (I)-(III) of the following type coherently bonded to one another: (I) a layer made of a polyamide moulding composition with 0.1-5.0 percent by weight content of polyethyleneimine (PEI) or of a copolymer or derivative thereof; (II) a polyurethane layer; (III) a layer of mineral glass.

2. The composite according to claim 1, wherein said layer made of a polyamide moulding consists of a thermoplastic polyamide moulding composition consisting of: (A) 30-99.9 percent by weight of at least one polyamide selected from the group consisting of: at least one aliphatic or semiaromatic polyamide, in each case with C:N ratio of at least 8; at least one aliphatic or semiaromatic polyamide composed of at least one dicarboxylic acid and of at least one diamine, without lactams or aminocarboxylic acids or without lactams and aminocarboxylic acids or with a proportion below 50 mol percent based on the entirety of dicarboxylic acids and diamine as 100 mol percent, of at least one of lactams or aminocarboxylic acids; and mixtures thereof; (B) 0.1-5.0 percent by weight of at least one polyethyleneimine (PEI) or copolymers or derivatives thereof; (C) 0-60 percent by weight of fillers and/or reinforcing materials; (D) 0-5.0 percent by weight of additives; where the entirety of (A)-(D) provides 100% of the thermoplastic polyamide moulding composition.

3. The composite according to claim 2, wherein the proportion of component (A) present is 32-94.4 percent by weight; or wherein component (A) consists of: (A1) 20-100 percent by weight of a polyamide selected from the group consisting of: at least one aliphatic semicrystalline polyamide based on acyclic dicarboxylic acids and on acyclic diamines, at least one semiaromatic semicrystalline polyamide based on dicarboxylic acids and on diamines, or a mixture thereof; (A2) 0-80 percent by weight, of a polyamide selected from the group consisting of: at least one amorphous semiaromatic polyamide, at least one cycloaliphatic polyamide, or a mixture thereof, wherein the percentage by weight of components (A1) and (A2) together provide 100% by weight of component (A) or wherein the melting point of the polyamides of component (A1) is at least 170 C.; or wherein the polyamides of component (A2) are selected from the group consisting of: the cycloaliphatic polyamides MACM12/PACM12, MACM14/PACM14, MACM16/PACM16, MACM18/PACM18, 6I/6T/MACMI/MACMT/12, 6I/MACMI/MACMT, 6I/PACMI/PACMT, 6I/6T/MACMI, 6I/6T/612/MACMI/MACMT/MACM12, MACMI/MACMT/12, 6/IPDT, 6I/6T/614/MACMI/MACMT/MACM14, 6I/6T/616/MACMI/MACMT/MACM16, MACMI/MACM36, 12/PACMI, 12/MACMT, 6I/PACMT, MACM10, MACM12, MACM14, MACM16, MACM18, MACMI/12, PACM10, PACM12, MACM14, PACM16, PACM18, PACMI/12, TMDC10, TMDC12, TMDC16, TMDC18, MACMT/MACMI/12, PACMT/PACMI/12, amorphous semiaromatic polyamides 6I, 6/6I, MXDI, MXDI/6I, MXD6/MXDI, 6T/6I, 10T/10I, 3-6T and mixtures thereof, where the systems 6T/6I or 10T/10I comprise a proportion below 50 mol % of 6T or 10T units; or wherein the glass transition temperature Tg of the polyamides of component (A2) is above 90 C.

4. The composite according to claim 2, wherein the moulding composition is free from aluminium salts, is free from polyethyleneimine copolymers, and is free from iron powder.

5. The composite according to claim 2, wherein the proportion present in the moulding composition of component (B) is in the range 0.5-4.0 percent by weight.

6. The composite according to claim 2, wherein the polyethyleneimine of component (B) is a branched polyethyleneimine; or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with number-average molar mass M.sub.n in the range 500-50 000 g/mol, or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with content of primary amino groups in the range 5000-20 000 eq/g; or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with water content below 4 percent by weight.

7. The composite according to claim 2, wherein the proportion of component (C) present is in the range 5-60 percent by weight; or wherein component (C) consists of: (C1) 0-40 percent by weight of particulate filler; (C2) 60-100 percent by weight of fibrous reinforcing material, wherein the percentages by weight of components (C1) and (C2) together provide 100 percent by weight of component (C).

8. The composite according to claim 2, wherein the proportion of component (D) present is in the range 0.1-4.0 percent by weight; or wherein the additives of component (D) are selected from the group consisting of: ageing retarders, antioxidants, antiozonants, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers, organic heat stabilizers, other stabilizers, conductivity additives, optical brighteners, processing aids, nucleating agents, crystallization accelerators, crystallization retarders, flow promoters, lubricants, mould-release agents, plasticizers, organic pigments and dyes, marking materials and mixtures thereof.

9. The composite according to claim 1, wherein the layer (I) consists of a polyamide moulding composition.

10. The composite according to claim 1, wherein the polyurethane layer (II) is based on a reactive polyurethane (PU) adhesive, or wherein the polyurethane layer (II) is based on a one-component polyurethane hot-melt adhesive system, or wherein the polyurethane layer (II) is based on a crosslinked system.

11. A method of using a thermoplastic moulding composition according to claim 1 for the production of a composite.

12. A process for the production of a composite according to claim 1, wherein a polyamide is mixed with a polyethyleneimine (PEI) or with a copolymer or derivative thereof, with or without fibrous reinforcing materials and additional particulate materials, this material is processed in an injection-moulding process or extrusion process to give a moulding, and this moulding, as layer (I), is placed by way of a layer (II) of polyurethane adhesive in contact with a layer (III) made of mineral glass, and then the layer (II) is hardened.

13. A method of using a polyethyleneimine (PEI) or of a derivative or copolymer thereof in a polyamide composition to improve the adhesion to polyurethane.

14. The method according to claim 13, wherein the proportion of the polyethyleneimine in the polyamide moulding composition is in the range 0.5-4.0 percent by weight, based on the total weight of the polyamide moulding composition.

15. The method according to claim 13, wherein the polyethyleneimine of component (B) is a branched polyethyleneimine; or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with number-average molar mass M.sub.n in the range 500-50 000 g/mol, preferably in the range 1000-2500 g/mol, or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with content of primary amino groups in the range 5000-20 000 eq/g; or wherein the polyethyleneimine is a branched polyethyleneimine with water content below 4 percent by weight.

16. A composite according to claim 2, wherein the proportion of component (A) present is in the range 44.5-69.0 percent by weight; or wherein component (A) consists of: (A1) 40-60 percent by weight, of a polyamide selected from the group consisting of: at least one aliphatic semicrystalline polyamide based on acyclic dicarboxylic acids and on acyclic diamines, at least one semiaromatic semicrystalline polyamide based on dicarboxylic acids and on diamines, or mixtures thereof; (A2) 40-60 percent by weight, of a polyamide selected from the group consisting of: at least one amorphous semiaromatic polyamide, of at least one cycloaliphatic polyamide, or a mixture thereof, wherein the percentage by weight of components (A1) and (A2) together provide 100% by weight of component (A), or wherein the melting point of the polyamides of component (A1) is at least in the range 180-340 C., or if the polyamides are aliphatic 180-230 C.; or wherein the polyamides of component (A2) are selected from the group consisting of: 6T:6I, 10T/10I with a composition range of 20:80 to 45:55; or wherein the glass transition temperature Tg of the polyamides of component (A2) is above 110 C.

17. The composite according to claim 2, wherein component (A) consists of: (A1) 20-100 percent by weight of a polyamide selected from the group consisting of: at least one aliphatic semicrystalline polyamide based on acyclic dicarboxylic acids and on acyclic diamines, at least one semiaromatic semicrystalline polyamide based on dicarboxylic acids and on diamines, or a mixture thereof; (A2) 0-80 percent by weight, of a polyamide selected from the group consisting of: at least one amorphous semiaromatic polyamide, at least one cycloaliphatic polyamide, or a mixture thereof, wherein the percentage by weight of components (A1) and (A2) together provide 100% by weight of component (A), and wherein the C:N ratio of at least one, or all, of the polyamides of component (A1) is at least 8.

18. The composite according to claim 2, wherein component (A) consists of: (A1) 20-100 percent by weight of a polyamide selected from the group consisting of: at least one aliphatic semicrystalline polyamide based on acyclic dicarboxylic acids and on acyclic diamines, at least one semiaromatic semicrystalline polyamide based on dicarboxylic acids and on diamines, or a mixture thereof; (A2) 0-80 percent by weight, of a polyamide selected from the group consisting of: at least one amorphous semiaromatic polyamide, at least one cycloaliphatic polyamide, or a mixture thereof, wherein the percentage by weight of components (A1) and (A2) together provide 100% by weight of component (A), and wherein the C:N ratio of at least one, or all, of the polyamides of component (A1) is 9.

19. The composite according to claim 2 wherein component (A) consists of: (A1) 20-100 percent by weight of a polyamide selected from the group consisting of: at least one aliphatic semicrystalline polyamide based on acyclic dicarboxylic acids and on acyclic diamines, at least one semiaromatic semicrystalline polyamide based on dicarboxylic acids and on diamines, or a mixture thereof; (A2) 0-80 percent by weight, of a polyamide selected from the group consisting of: at least one amorphous semiaromatic polyamide, at least one cycloaliphatic polyamide, or a mixture thereof, wherein the percentage by weight of components (A1) and (A2) together provide 100% by weight of component (A), wherein the polyamides of component (A1) are selected as semicrystalline aliphatic polyamides from the group consisting of: PA 46, 66, 66/6, 69, 610, 612, 614, 616, 618, 810, 1010, 1012, 1212, 11,12, 6/12, 66/6/610, or are selected as semicrystalline semiaromatic polyamides from the group consisting of: PA 6T/6I, 6T/66, 6T/6I/66, 6T/610, 6T/612, 6T/614, 6T/616, 9T, 9MT, 10T, 12T, 10T/6T, 11/10T, 12/10T, 11/9T, 12/9T, 10T/1010, 10T/612; and/or wherein the polyamides of component (A2) are selected from the group consisting of: 6T:6I and, respectively, 10T/10I with a composition range of 25:75 to 40:60; or wherein the glass transition temperature Tg of the polyamides of component (A2) is above 110 C.

20. The composite according to claim 2, wherein the proportion present in the moulding composition of component (B) is in the range 0.8-3.5 percent by weight.

21. The composite according to claim 2, wherein the polyethyleneimine of component (B) is a branched polyethyleneimine having a ratio of primary to secondary amines in the range 1:2-2:1, or a ratio of primary to tertiary amines in the range 3:1-1:1, or a ratio of secondary to tertiary amines in the range 3:1-1:1; or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with number-average molar mass M.sub.n in the range 1000-2500 g/mol, or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with content of primary amino groups in the range 7 000-12 000 eq/g; or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with water content below 2 percent by weight.

22. The composite according to claim 2, wherein the proportion of component (C) present is in the range 30-50 percent by weight; or wherein component (C) consists of: (C1) 3-25 percent by weight of particulate filler; (C2) 75-97 percent by weight of fibrous reinforcing material, wherein the percentages by weight of components (C1) and (C2) together provide 100 percent by weight of component (C).

23. The composite according to claim 2, wherein component (C) consists of: (C1) 0-40 percent by weight of particulate filler selected from the group consisting of: carbon black, talc, mica, silicates, quartz, wollastonite, kaolin, silicas, magnesium carbonate, magnesium hydroxide, chalk, ground or precipitated calcium carbonate, limestone, feldspar, inorganic pigments, inclusive of barium sulfate, zinc oxide, zinc sulfide, lithopone, titanium dioxide (rutile, anatase), iron oxide, iron manganese oxide, metal oxides, inclusive of copper iron spinel, copper chromium oxide, zinc iron oxide, cobalt chromium oxide, cobalt aluminium oxide, magnesium aluminium oxide, mixed copper chromium magnesium oxides, mixed copper manganese iron oxides, rutile pigments inclusive of titanium zinc rutile, nickel antimony titanate, chromium antimony titanate, magnetically hard and magnetically soft metals and alloys and ceramics, hollow-sphere silicate fillers, aluminium oxide, boron nitride, boron carbide, aluminium nitride, calcium fluoride and mixtures thereof; (C2) 60-100 percent by weight of fibrous reinforcing material selected from the group consisting of: glass fibres, carbon fibres, graphite fibres, aramid fibres, nanotubes and mixtures thereof, where the fibres of component (C2) can have circular or non-circular cross section, wherein the percentages by weight of components (C1) and (C2) together provide 100 percent by weight of component (C).

24. The composite according to claim 2, wherein the proportion of component (D) present is in the range 0.2-2.0 percent by weight; or wherein the additives of component (D) are selected from the group consisting of: ageing retarders, antioxidants, antiozonants, light stabilizers, UV stabilizers, UV absorbers, UV blockers, inorganic heat stabilizers based on copper halides and on alkali metal halides, organic heat stabilizers, other stabilizers, conductivity additives, optical brighteners, processing aids, nucleating agents, crystallization accelerators, crystallization retarders, flow promoters, lubricants, mould-release agents, plasticizers, organic pigments and dyes, marking materials and mixtures thereof.

25. The composite according to claim 1, wherein the polyurethane layer (II) is based on a reactive one-component polyurethane adhesive or two-component polyurethane adhesive, or is based on a reactive polyurethane hot-melt adhesive, which is moisture-crosslinking, or wherein the polyurethane layer (II) is based on a chemically or physically crosslinked system, or a moisture-crosslinked or electromagnetically crosslinked system.

26. A process for the production of a composite according to claim 12, wherein a polyamide is mixed with a polyethyleneimine (PEI) or with a copolymer or derivative thereof to give a polyamide, this material is processed in an injection-moulding process or extrusion process to give a moulding, and this moulding, as layer (I), is placed by way of a layer (II) of polyurethane adhesive in contact with a layer (III) made of mineral glass, and then the layer (II) is hardened, in that the layer (II) is crosslinked, with exposure to moisture or exposure to electromagnetic waves.

27. The method according to claim 13 of using a polyethyleneimine (PEI) or of a derivative or copolymer thereof in a polyamide composition to improve the adhesion to a reactive polyurethane (PU) adhesive, in the form of a one-component polyurethane adhesive or two-component polyurethane adhesive, including a reactive polyurethane hot-melt adhesive, which is moisture-crosslinking, to form a composite.

28. The method according to claim 13, wherein the proportion of the polyethyleneimine in the polyamide moulding composition is in the range 0.8-3.5 percent by weight, based on the total weight of the polyamide moulding composition.

29. The method according to claim 13, wherein the polyethyleneimine of component (B) is a branched polyethyleneimine that has a ratio of primary to secondary amines in the range 1.2:1-1:1.2 or a ratio of primary to tertiary amines in the range 2:1-1.4:1, or a ratio of secondary to tertiary amines in the range 2:1-1.2:1; or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with number-average molar mass M.sub.n in the range 1000-2500 g/mol, or wherein the polyethyleneimine of component (B) is a branched polyethyleneimine with content of primary amino groups in the range 7 000-12 000 eq/g; or wherein the polyethyleneimine is a branched polyethyleneimine with water content below 2 percent by weight.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0150] Preferred embodiments of the invention are described below with reference to the drawings, which serve merely for illustration and are not to be interpreted as restrictive:

[0151] FIGS. 1a-1e in the drawing shows: the various phases of the experimental set-up for measuring adhesion.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0152] The components stated in Table 1 were compounded in the proportions stated in Tables 2 and 3 in an twin-screw extruder from Werner and Pfleiderer with screw diameter 25 mm with prescribed process parameters (see Table 4); the polyamide granulates and the added substances were metered here into the feed zone, whereas the glass fibre was metered into the polymer melt by way of a side-feeder 3 barrel sections before the die. The compounded materials collated in Tables 2 and 3 were drawn off as strand from a die with diameter 3 mm and granulated after water-cooling. The granulate was dried in vacuo at 30 mbar for 24 hours at 100 C.

TABLE-US-00001 TABLE 1 Materials used in the Inventive Examples and Comparative Examples Components Description Manufacturer Polyamide 1 PA 612, .sub.rel. = 1.78, Tm = 215 C., AG = 21 eq/g EMS-CHEMIE AG Polyamide 1A PA 612, .sub.rel. = 1.45, AG = 210 eq/g EMS-CHEMIE AG Polyamide 2 PA 616, .sub.rel. = 1.94, Tm = 195 C., AG = 32 eg/g EMS-CHEMIE AG Polyamide 3 PA 61/6T (67:33), .sub.rel. = 1.52, T.sub.g = 125 C., AG = 45 EMS-CHEMIE AG eq/g Polyamide 4 PA 61/6T (67:33), .sub.rel. = 1.41, T.sub.g = 122 C., AG = 287 EMS-CHEMIE AG eq/g Polyamide 5 PA MACM16, .sub.rel. = 1.75, T.sub.g = 140 C., AG = 34 eq/g EMS-CHEMIE AG Polyamide 6 PA 6, *.sub.rel. = 2.70 (1% in sulfuric acid), T.sub.m = 222 C., EMS-CHEMIE AG AG = 23 eq/g Glass fibre Vetrotex 995 EC10-4.5, E glass, diameter = 10 m, Owens Corning length = 4.5 mm, round cross section Fiberglass (US) Carbon black Black Pearls 1100, Iodine absorption (g/kg) 20, Cabot Corp. (CH) OAN (cc/100 g): 105 (ASTM D2414) Mica Mica HLM 100; Muskovite mica, density: 2.8 g/cm.sup.3; Krntner median diameter: 50 m (d50), 315 m (d98); aspect Montanindustrie (AT) ratio: 40:1 PEI Lupasol G20, polyethyleneimine (CAS 25987-06-8), BASF SE (DE) number-average molar mass M.sub.n = 1200 g/mol, water content at most 2 percent by weight, ratio of primary/secondary/tertiary amines 1:0.91:0.64 Stabilizer Mixture of Irganox 1010 (CAS 6683-19-8), Anox 20 BASF SE system (CAS 6683-19-8) and Hostanox PAR24 (CAS 31570- Addivant 04-4) in the ratio 7:3:3 Clariant Int. Ltd. .sub.rel Relative viscosity determined in accordance with ISO 306, 0.5 g polymer granulate in 100 ml m-cresol, 20 C., for polyamides 1 to 5 *.sub.rel Relative viscosity determined in accordance with ISO 306, sulfuric acid, 1.0% by weight, 20 C., for polyamide 6 AG Concentration of terminal amino groups in [eq/g] T.sub.g, T.sub.m Glass transition temperature, melting point determined in accordance with ISO 11357 at heating rate 20 C./min

TABLE-US-00002 TABLE 2 Moulding compositions according to the invention Components Unit IE1 IE2 IE3 IE4 IE5 IE6 IE7 IE8 Polyamide 1 % by 28.79 28.04 28.99 57.58 43.20 28.04 28.04 (component A1) wt. Polyamide 2 % by 28.79 (component A1) wt. Polyamide 3 % by 28.79 28.04 28.99 14.38 (component A2) wt. Polyamide 4 % by 28.04 28.04 (component A2) wt. Polyamide 5 % by 28.79 (component A2) wt. Stabilizer % by 0.42 0.42 0.42 0.42 0.42 0.42 0.42 0.42 wt. Carbon black % by 0.50 0.50 0.50 0.50 0.50 0.70 0.50 0.50 wt. Mica % by 5.00 5.00 5.00 5.00 5.00 4.80 5.00 5.00 wt. Glass fibre % by 35.00 35.00 35.00 35.00 35.00 35.00 35.00 35.00 wt. PEI % by 1.50 3.00 1.10 1.50 1.50 1.50 3.00 1.50 wt. Properties Terminal amino eq/g 220 395 165 228 217 297 472 229 groups Modulus of MPa 12200 12100 12200 12000 11900 12200 11800 11000 elasticity Tensile stress at MPa 181 170 176 180 176 180 167 152 break Elongation at break % 2.2 2.1 2.2 2.5 2.4 2.3 2.1 5.3 Impact resistance, kJ/m.sup.2 47 32 55 65 56 47 38 51 Charpy, 23 C. Notched impact kJ/m.sup.2 8 7 9 10 8 8 7 10 resistance, Charpy, 23 C. Adhesion mJ 996 1013 915 654 915 1013 1078 817

TABLE-US-00003 TABLE 3 Moulding compositions of the Comparative Examples Components Unit CE1 CE2 CE3 CE4 CE5 Polyamide 1 % by 29.54 59.08 wt. Polyamide 1A % by 29.54 wt. Polyamide 3 % by 29.54 59.08 wt. Polyamide 4 % by 29.54 wt. Polyamide 6 % by 67.51 wt. Stabilizer % by 0.42 0.42 0.42 0.42 0.14 wt. Carbon black % by 0.50 0.50 0.50 0.50 wt. Mica % by 5.00 5.00 5.00 5.00 wt. Glass fibre % by 35.00 35.00 35.00 35.00 30.0 wt. PEI % by 2.00 wt Calcium montanate % by 0.35 wt Properties Terminal amino eq/g 27 24 30 242 33 groups Modulus of MPa 11540 11300 12000 12500 9600 elasticity Tensile stress at MPa 189 180 195 151 161 break Elongation at break % 3.0 3.5 2.5 1.1 2.5 Impact resistance, kJ/m.sup.2 68 85 47 12 45 Charpy, 23 C. Notched impact kJ/m.sup.2 9 12 8 5 8 resistance, Charpy, 23 C. Adhesion mJ 327 229 327 423 457

TABLE-US-00004 TABLE 4 Compounding process parameters Parameter Temperature profile [ C.] Temperatur Zone 1 80-100 Temperatur Zone 2 230-250 Temperatur Zone 3 to 10 250-260 Temperatur Zone 11 250-270 Temperatur Zone 12 230-270 Temperature of die head 260-280 Melt temperature 250-280 Throughput [kg/h] 8-12 Screw rotation rate [rpm] 150-200

[0153] The compounded materials were injection-moulded in an Arburg Allrounder 320-210-750 injection-moulding machine at defined cylinder temperatures of 240 to 280 C. in zones 1 to 4 and with mould temperature 100 C. to give test samples.

[0154] Test Methods

[0155] The following test methods were used for the purposes of this application:

[0156] Melting Point (Tm) and Enthalpy of Fusion (Hm):

[0157] Melting point and enthalpy of fusion were determined in accordance with ISO 11357-3 (2013) on the granulate. The DSC (differential scanning calorimetry) measurements were made at heating rate 20 K/min.

[0158] Glass Transition Temperature, Tg:

[0159] Glass transition temperature T g was determined in accordance with ISO 11357-2 (2013) on granulate by means of differential scanning calorimetry (DSC). This was carried out with heating rate 20 K/min in each of the two heating procedures. After the first heating procedure, the specimen was quenched in dry ice. The glass transition temperature (T.sub.g) was determined during the second heating procedure. The midpoint of the glass transition region, stated as glass transition temperature, was determined by the half height method.

[0160] Relative Viscosity, .sub.rel:

[0161] Relative viscosity was determined in accordance with ISO 307 (2007) at 20 C. For this, 0.5 g of polymer granulate was weighed into 100 ml of m-cresol (unless otherwise stated), and relative viscosity (RV) was calculated by a method based on Section 11 of the Standard as follows: RV=t/t.sub.0.

[0162] Tensile Modulus of Elasticity:

[0163] Tensile modulus of elasticity was determined in accordance with ISO 527 (2012) at 23 C. with tensile velocity 1 mm/min on an ISO tensile specimen (Type A1, 17020/104) produced in accordance with the standard: ISO/CD 3167 (2003).

[0164] Tensile Stress at Break and Elongation at Break:

[0165] Tensile stress at break and elongation at break were determined in accordance with ISO 527 (2012) at 23 C. with tensile velocity 5 mm/min on a Type A1 ISO tensile specimen (17020/104 mm) produced in accordance with the standard ISO/CD 3167 (2003).

[0166] Charpy Impact Resistance:

[0167] Charpy impact resistance was determined in accordance with ISO 179/2*eU (1997, *2=instrumented) at 23 C. on a Type B1 ISO test specimen (80104 mm) produced in accordance with the standard ISO/CD 3167 (2003).

[0168] Charpy Notched Impact Resistance:

[0169] Charpy notched impact resistance was determined in accordance with ISO 179/2*eA (1997, *2=instrumented) at 23 C. on a Type B1 ISO test specimen (80104 mm) produced in accordance with the standard ISO/CD 3167 (2003).

[0170] Adhesion:

[0171] The following procedure was used to measure adhesion: a square test sample 1 with side length a 50 mm and thickness 3.5 mm, and also with a central circular aperture 2 with diameter b 10 mm was produced by injection moulding as stated above (cf. FIG. 1a). An adhesive tape strip of thickness 240 m was then used (cf. FIG. 1b) to produce a square 3 with exterior width d 17 mm and interior width c 14 mm. A strip 4 of breadth 1 mm of EH9651 PU hot-melt adhesive from H.B. Fuller was then applied while warm on the internal side of the same square, likewise at a thickness of 240 m and then (cf. FIG. 1c) a square panel 5 of mineral glass (Gorilla Glass 5, Corning) with side length e 20 mm and thickness 3 millimetres was superposed with the aid of a template. The composite was then dried and, respectively, the PU adhesive crosslinked (cf. FIG. 1d) for 2 hours under a load 6 of 500 g at 23 and 50% relative moisture.

[0172] Adhesion was measured in a set-up according to FIG. 1e), where a cylindrical metallic body 8 with diameter 7 mm, weighing 50 g, 100 g, or 120-220 g, as required by each test, was dropped from increasing height in the range 50-500 mm in controlled manner through the aperture 2 onto the glass panel 5 until the composite separated; the kinetic energy of the body 8 on impact in the final damage-free drop test was taken as adhesion value.

[0173] Terminal Amino Group Concentration:

[0174] For determination of terminal amino groups, the polyamide is dissolved in m-cresol under hot conditions and isopropanol is admixed (m-cresol:isopropanol=2:1 volumetrically). Content of terminal amino groups is determined by potentiometric titration with perchloric acid.

[0175] Discussion of results: The measured values reveal the following: in the absence of polyethyleneimine in the polyamide matrix (cf. CE1-CE3), although good mechanical values are obtained adhesion is poor. This problem cannot be solved by using a polyamide with increased terminal amino group concentration as polyamide matrix (cf. CE4): tensile stress at break and elongation at break decrease sharply here, i.e. mechanical properties deteriorate, and no significant improvement of adhesion can be obtained.

[0176] It is moreover apparent that use of polyethyleneimine as additional material in a polyamide 6 (cf. CE6) does not lead to adequate adhesion.

[0177] In other words, good adhesion is achievable only with a polyamide matrix according to the claims with the claimed proportions of polyethyleneimine (IE1-IE7).

LIST OF REFERENCE SIGNS

[0178] 1 Square polyamide test sample [0179] 2 Aperture in 1 [0180] 3 Tape square [0181] 4 PU adhesive [0182] 5 Square glass panel [0183] 6 Weight [0184] 7 Template [0185] 8 Falling body [0186] a Side length of 1 [0187] b Diameter of 2 [0188] c Interior width of 3 [0189] d External width of 3 [0190] e Side length of 5