MATERIAL COMPOSITES

Abstract

A composite containing directly adjoining and firmly bonded sections (I) and (II) of the following type: (I) section, formed from a thermoplastic moulding compound FM-1 containing at least one polyamide (A) and optionally fillers and reinforcing materials (C) and additives (D); (II) section, formed from a thermoplastic moulding compound containing at least one olefinic and/or vinyl aromatic polymer (E) and optionally fillers and reinforcing agents (F), plasticisers (G) and additives (H);
wherein the moulding compound FM-1 or FM-2 contains 0.1 to 5.0 percent by weight of polyethyleneimine (B) or a copolymer or derivative thereof and a method for producing such composites.

Claims

1. A composite containing directly adjoining and firmly bonded sections (I) and (II) of the following type: (I) section, formed from a thermoplastic moulding compound FM-1 containing at least one polyamide (A) and optionally fillers and reinforcing materials (C) and additives (D); (II) section, formed from a thermoplastic moulding compound FM-2 containing at least one olefinic and/or vinyl aromatic polymer (E) and optionally fillers and reinforcing agents (F), plasticisers (G) and additives (H); wherein the moulding compound FM-1 or FM-2 contains 0.1 to 5.0 percent by weight of polyethyleneimine (B) or a copolymer or derivative thereof.

2. The composite according to claim 1, wherein the thermoplastic moulding compound FM-1 contains the following components: (A) 30-99.9 percent by weight of at least one polyamide; (B) 0.1-5.0 percent by weight polyethyleneimine or copolymers or derivatives thereof; (C) 0-60 percent by weight fillers and/or reinforcing materials; (D) 0-5.0 percent by weight additives other than (A)-(C); the sum of (A)-(D) being 100 percent by weight of the thermoplastic moulding compound FM-1, and in that the thermoplastic moulding compound FM-2 contains the following components: (E) 45-100 percent by weight of at least one olefinic and/or vinyl aromatic polymer; (F) 0-15 percent by weight fillers and/or reinforcing materials; (G) 0-35% by weight plasticiser; (H) 0-5.0% by weight additives other than (E), (F) and (G); the sum of (E)-(H) being 100 percent by weight of the thermoplastic moulding compound FM-2.

3. The composite according to claim 1, wherein the at least one polyamide (A) is present in a proportion of 31-79.5 percent by weight, preferably 40-74 percent by weight, based on the total weight of the moulding compound FM-1; and/or the at least one olefinic and/or vinyl aromatic polymer (E) is present in a proportion of 55-94.9 percent by weight, particularly preferably 65-89.8 percent by weight, based on the total weight of the moulding compound FM-2.

4. The composite according to claim 1, wherein the thermoplastic moulding compound FM-1 contains the following components: (A) 35-100 percent by weight of at least one polyamide; (C) 0-60 percent by weight fillers and/or reinforcing materials; (D) 0-5.0% by weight additives other than (A) and (C); the sum of (A), (C) and (D) being 100 percent by weight of the thermoplastic polyamide moulding compound FM-1, and in that the thermoplastic moulding compound FM-2 contains the following components: (E) 40-99.9 percent by weight of at least one olefinic and/or vinyl aromatic polymer; (B) 0.1-5.0 percent by weight polyethyleneimine or copolymers or derivatives thereof; (F) 0-15 percent by weight fillers and/or reinforcing materials; (G) 0-35% by weight plasticiser; (H) 0-5.0 percent by weight additives other than (E), (F), (G) and (B); the sum of (B) and (E)-(H) being 100 percent by weight of the thermoplastic moulding compound FM-2.

5. The composite according to claim 4, wherein, the at least one polyamide (A) is present in a proportion of 35-80 percent by weight, preferably 43-74.8 percent by weight, based on the total weight of the moulding compound FM-1; and/or the at least one olefinic and/or vinyl aromatic polymer (E) is present in a proportion of 51-94.4 percent by weight, particularly preferably 62-89 percent by weight, based on the total weight of the moulding compound FM-2.

6. The composite according to claim 1, wherein the polyethyleneimine (B) is present in a proportion of 0.5-4.0 percent by weight, preferably 0.8-3.0 percent by weight, based on the total weight of the moulding compound FM-1 or FM-2.

7. The composite according to claim 1, wherein the at least one polyamide (A) of the moulding compound FM-1 is selected as partially crystalline, acyclic, aliphatic polyamides (A1) from the group consisting of: 46, 56, 66, 66/6, 69, 610, 612, 614, 616, 618, 810, 1010, 1012, 1014, 1016, 1212, 11, 12, 6/12, 66/6/610, wherein 66, 612, 614 and 616 are preferred; and/or partially crystalline, partially aromatic polyamides (A2) from the group consisting of: 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 cycloaliphatic polyamides (A3) from the group consisting of: MACM12/PACM12, MACM14/PACM14, MACM16/PACM16, MACM18/PACM18, 6I/6T/MACMI/MACMT/12, 6/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; and/or amorphous, partially aromatic polyamides (A4) from the group consisting of: 5, 6, 6/6I, MXDI, MXDI/6I, MXD6/MXDI, 5T/5I, 6T/6I, 10T/10I, 3-6T (3-6=2,2,4- or 2,4,4-trimethylhexanediamine) or mixtures thereof, the systems 5T/5I, 6T/6I or 10T/10I having a proportion of less than 50 mol % 5T, 6T or 10T units, and a composition range 5T:5I, 6T:6I or 10T/10I from 20:80 to 45:55, in particular 25:75 to 40:60, in each case stated as mol %, is preferred.

8. The composite according to claim 1, wherein the at least one polyamide (A) of the moulding compound FM-1 contains the following components or consists of the following components: 20-100 percent by weight, preferably 40-80 percent by weight of at least one partially crystalline, acyclic, aliphatic polyamide (A1) and/or at least one partially aromatic, partially crystalline polyamide (A2), 0-80 percent by weight, preferably 20-60 percent by weight of at least one cycloaliphatic polyamide (A3) and/or an amorphous, partially aromatic polyamide (A4), the percent by weight of components (A1) to (A4) adding up to 100 percent by weight of component (A); or 20-80 percent by weight, preferably 25-75 percent by weight of at least one partially crystalline, acyclic, aliphatic polyamide (A1) selected from the group consisting of PA66, PA610, PA612, PA614 and PA616; 20-80 percent by weight, preferably 25-75 percent by weight of at least one amorphous, partially aromatic polyamide (A4) selected from the group consisting of 5T/5I, 6T/6I and 10T/10I, the percent by weight of components (A1) and (A4) adding up to 100 percent by weight of component (A).

9. The composite according to claim 1, wherein the moulding compound FM-2 contains as component (E) at least one vinyl aromatic polymer, preferably at least 50 percent by weight, in particular at least 70 percent by weight, each based on the total amount of (E), of a vinyl aromatic polymer and optionally contains at least one polyolefin.

10. The composite according to claim 1, wherein the at least one olefinic and/or vinyl aromatic polymer (E) of the moulding compound FM-2 is selected from the group consisting of: styrene-ethylene-butylene-styrene block copolymers (SEBS), styrene-ethylene-propylene-styrene block copolymers (SEPS), styrene-butylene-styrene block copolymers (SBS), styrene-styrene-butylene-styrene block copolymers (SSBS), polyethylene (PE), polypropylene (PP), polybutadiene (PB), poly-4-methylpentene, ethylene-propylene copolymers, ethylene-butene copolymers, ethylene-methylhexadiene copolymers, propylene-methylhexadiene copolymers, ethylene-octene copolymers, ethylene-propylene-butene copolymers, ethylene-propylene-hexene copolymers, ethylene-propylene-methylhexadiene copolymers, poly(ethylene-vinyl acetate) (EVA), ethylene-ethyl acrylate copolymer (EEA), ethylene-hexene copolymer, ethylene-propylene-diene terpolymers and mixtures of these polymer materials.

11. The composite according to claim 1, wherein the at least one olefinic and/or vinyl aromatic polymer (E) of the moulding compound FM-2 is grafted with carboxylic acid or carboxylic anhydride groups; and/or the at least one olefinic and/or vinyl aromatic polymer (E) is grafted with acrylic acid, methacrylic acid or maleic anhydride; and/or the degree of grafting is 0.1 to 4.0, preferably 0.4 to 2.5 and particularly preferably 0.5 to 2.0 percent by weight, based on the grafted polymer (E).

12. The composite according claim 1, wherein the polyethyleneimine of component (B) is a branched polyethyleneimine, which preferably has a ratio of primary to secondary amines in the range of 1:2-2:1, preferably in the range of 1.2:1-1:1.2 and/or a ratio of primary to tertiary amines in the range of 3:1-1:1, preferably in the range of 2:1-1.4:1 and/or a ratio of secondary to tertiary amines in the range of 3:1-1:1, preferably in the range of 2:1-1.2:1; and/or in that the polyethyleneimine of component (B) is a branched polyethyleneimine with a number average molar mass Mn in the range of 500-50,000 g/mol, preferably in the range of 1000-2500 g/mol, and/or in that the polyethyleneimine of component (B) is a branched polyethyleneimine with a content of primary amino groups in the range of 5000-20,000 μeq/g, preferably in the range of 7,000-12,000 μeq/g; and/or in that the polyethyleneimine of component (B) is a branched polyethyleneimine with a water content of less than 4 percent by weight, preferably less than 3 percent by weight, particularly preferably less than 2 percent by weight.

13. The composite according to claim 1, wherein the moulding compound FM-1 contains the fillers and reinforcing materials of the component (C) in a proportion in the range of 20-60 percent by weight, preferably in the range of 25-55 percent by weight; and/or the moulding compound FM-2, which contains the fillers and reinforcing materials of component (F) in a proportion in the range of 0-10 percent by weight, is preferably free of component (F); and/or that components (C) and (F) consist of: particulate filler (C1) and (F1), particularly preferably selected from the group consisting of: soot, talc, mica, silicates, quartz, wollastonite, kaolin, silicic acids, magnesium carbonate, magnesium hydroxide, chalk, ground or precipitated calcium carbonate, lime, feldspar, inorganic pigments, including barium sulphate, zinc oxide, zinc sulphide, lithopone, titanium dioxide (rutile, anatase), iron oxide, iron manganese oxide, metal oxides, especially spinels, including copper iron spinel, copper chromium oxide, zinc-iron oxide, cobalt-chromium oxide, cobalt-aluminium oxide, magnesium aluminium oxide, copper-chromium-manganese mixed oxides, copper-manganese-iron mixed oxides, rutile pigments including titanium zinc rutile, nickel antimony titanate, chromium antimony titanate, hard or soft magnetic metals or alloys or ceramics, hollow spherical silicate fillers, aluminium oxide, boron nitride, boron carbide, aluminium nitride, calcium fluoride and mixtures thereof; and/or fibrous reinforcing material (C2) and (F2), preferably selected from the group consisting of: glass fibres, carbon fibres, graphite fibres, aramid fibres, nanotubes or mixtures thereof, wherein the fibres of components (C2) and (F2) can have circular or non-circular cross-sectional areas.

14. The composite according to claim 1, wherein the additives of component (D) are present in the moulding compound FM-1 in a proportion in the range of 0.1-4.0 percent by weight, preferably 0.2-2.0 percent by weight; and/or the additives of component (H) are present in the moulding compound FM-2 in a proportion in the range 0.1-4.0 percent by weight, preferably 0.2-2.0 percent by weight; and/or that the additives of components (D) and (H) are selected from the group consisting of: stabilisers, aging inhibitors, antioxidants, antiozonants, light stabilisers, UV stabilisers, UV absorbers, UV blockers, inorganic heat stabilisers, in particular based on copper halides and alkali halides, organic heat stabilisers, conductivity additives, optical brighteners, processing aids, nucleating agents, crystallisation accelerators, crystallisation retarders, flow additives, lubricants, mould release agents, organic pigments and dyes, markers and mixtures thereof.

15. The composite according to claim 1, wherein the plasticiser of component (G) is present in the moulding compound FM-2 in a proportion in the range of 5-35 percent by weight, preferably 10-33 percent by weight; and/or that the plasticiser of component (G) is selected from the group consisting of paraffinic and naphthenic oils.

16. The composite according to claim 1, wherein the section (I), formed from the thermoplastic moulding compound FM-1, has a Shore hardness of at least 70D, preferably of at least 75D and particularly preferably of at least 80D, each determined according to ISO 7619-1 (2012-02) in the dry state and/or the section (II), formed from the thermoplastic moulding compound FM-2, has a Shore hardness of at most 60D, preferably of at most 50D and particularly preferably of at most 39D or 90A, each determined according to ISO 7619-1 (2012-02) in the dry state.

17. A method for producing a composite according to claim 1, wherein the composite is produced in an injection moulding process which comprises the following steps: (i) insertion of a moulded body, containing at least one section (I), formed from the moulding compound FM-1, into an injection mould or injection of the thermoplastic moulding compound FM-1 into an injection mould for shaping at least one section (I) and (ii) injection of the thermoplastic moulding compound FM-2 for shaping at least one section (II), wherein the melts of the moulding compounds FM-1 and FM-2 are introduced into the injection mould in parallel or successively without mixing or without substantial mixing, and wherein the sections (I) and (II) are in contact at least at one point.

18. Use of polyethyleneimine or a derivative or copolymer thereof in a composite containing sections (I), formed from a moulding compound FM-1 containing polyamide, and containing sections (II), formed from a moulding compound FM-2 containing olefinic and/or vinyl aromatic polymer, for improving the adhesion strength between the sections (I) and (II).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0160] The drawings in FIGS. 1 and 2 show the composite test specimen used and the holder for the roller peeling test for measuring the peel force. They serve only for explanation and are not to be interpreted restrictively.

[0161]

TABLE-US-00001 List of reference signs for FIGS. 1 and 2 1 Composite test specimen a Side length of 2 2 Frame, section (I) b Width of 2 3 Opening in the frame c Side length of 3 4 Tab, section (II) d Width of 3 5 Sprue side of section (II) e Side length of 4 6 Holder for roller peeling test f Width of 4 7 Deflection roller g Thickness of 2 8 Fixing rollers h Thickness of 4 Z Traction axis

DESCRIPTION OF PREFERRED EMBODIMENTS

[0162] Production of the Polyamide Moulding Compounds FM-1

[0163] The components given in Table 1 were compounded in the proportions given in Table 2 in a twin-screw extruder from Werner and Pfleiderer with a screw diameter of 25 mm for given process parameters (see Table 3), the polyamide granules and the additives being metered into the feed zone while the glass fibre was dosed into the polymer melt via a side feeder 3 housing units in front of the nozzle. The compounds summarised in Table 2 were drawn off as a strand from a nozzle with a 3 mm diameter and granulated after cooling with water. The granulate was dried for 24 hours at 100° C. in a vacuum of 30 mbar.

TABLE-US-00002 TABLE 1 Materials used in the examples and comparative examples Components Description Manufacturer Polyamide 1 PA 66, η.sub.rel. = 1.85, Tm = 260° C. EMS-CHEMIE AG (Component A1) Polyamide 2 PA 610, η.sub.rel. = 1.94, Tm = 195° C. EMS-CHEMIE AG (Component A1) Polyamide 3 PA 6I/6T (67:33), η.sub.rel. = 1.52, T.sub.g = 125° C. EMS-CHEMIE AG (Component A4) Kraton G1651 E SEBS, styrene content = 31.5% by weight Shell (Component E) Kraton FG1901GT SEBS-g-MAH, styrene content = 30% by weight, Shell (Component E) MAH content = 1.5% by weight Polybond 3002 Polypropylene (PP-g-MAH), T.sub.m = 157° C., MAH Additive (Component E) content = 0.3% by weight Polybond 3200 Polypropylene (PP-g-MAH), T.sub.m = 160° C., MAH Additive (Component E) content = 1.0% by weight Admer QB 510E Polypropylene (PP-g-MAH), MAH content = Mitsui (JP) 0.05% by weight Admer NF358E LLDPE (PE-g-MAH), MAH content = 0.2% by Mitsui (JP) weight Glass fibre Vetrotex 995 EC10-4.5, E-glass, diameter = 10 Owens Corning (Component C) μm, length = 4.5 mm, round cross-section Fiberglass (US) Soot Black Pearls 1100, Iodine absorption (g/kg): 20, Cabot Corp. (CH) (Component D) OAN (cc/100 g): 105 (ASTM D-2414) PEI Lupasol G20WFR, polyethyleneimine (CAS BASF SE (DE) (Component B) 25987-06-8), 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 Stabilisation Irganox 1010 (CAS 6683-19-8) BASF SE (Component D) Plasticiser MERKUR WOP 240 PB Paraffin oil (Paraffinum Sasol (DE) (Component G) Perliquidum) (CAS 8002-74-2) η.sub.rel Relative viscosity determined according to ISO 306, 0.5 g polymer granulate in 100 ml m-cresol, 20° C., for polyamides 1 to 5 MAH Maleic anhydride T.sub.g, T.sub.m Glass transition temperature, melting temperature determined according to ISO 11357 with a heating rate of 20° C./min

TABLE-US-00003 TABLE 2 Moulding compounds FM-1 (B1, B2 and VB1 to VB5) as well as adhesion strength to moulding compounds FM-2 (I) to (III) Components Unit B1 B2 VB1 VB2 VB3 VB4 VB5 Polyamide 1 % by 43.9 30.7 20.6 40.1 44.6 (Component A1) weight Polyamide 2 % by 68.0 69.5 (Component A1) weight Polyamide 3 % by 14.6 10.2 6.9 13.4 14.9 (Component A4) weight Stabiliser % by 0.3 0.3 0.3 0.3 0.3 0.3 0.3 weight Soot % by 0.2 0.2 0.2 0.2 0.2 0.2 0.2 weight Polybond 3002 % by 18.6 weight Admer QB 510E % by 32.0 weight Admer NF358E % by 6.0 weight Glass fibre % by 40.0 30.0 40.0 40.0 40.0 40.0 30.0 weight PEI % by 1.0 1.5 weight Characteristics Shore D 85 82 80 80 82 84 82 Modulus of elasticity MPa 16,100 9,100 10,200 10,100 12,000 16,400 9,200 Breaking stress MPa 225 154 147 83 189 228 155 Elongation at break % 2.0 3.9 2.1 1.5 3.0 2.0 4.0 Impact strength, kJ/m.sup.2 66 88 41 22 87 72 90 Charpy, 23° C. Notched impact kJ/m.sup.2 14 16 10 9 16 15 18 strength, Charpy, 23° C. Adhesione strength to moulding compound FM-2 (I) 0 d (48 h, 23° C.) N 122 127 28.1 19.9 24.2 108 111 2 d, 70° C., 62% RH N 125 125 26.6 19.6 17.5 20.4 22.7 5 d, 70° C., 62% RH N 117 122 21.1 19.1 11.2 16.2 15.1 Adhesion strength to moulding compound FM-2 (II) 0 d (48 h, 23° C.) N 177 70.6 2 d, 70° C., 62% RH N 170 45.6 5 d, 70° C., 62% RH N 157 38.8 Adhesion strength to moulding compound FM-2 (III) 0 d (48 h, 23° C.) N 0

TABLE-US-00004 TABLE 3 Process parameter for compounding Parameter Temperature profile [° C.] Temperature zone 1  80-100 Temperature zone 2 230-250 Temperature zone 3 to 10 250-260 Temperature zone 11 250-270 Temperature zone 12 230-270 Temperature of the nozzle head 260-280 Melt temperature 250-280 Throughput [kg/h] 10-12 Screw speed [rpm] 150-200

[0164] To determine the mechanical properties, the compounds were injected into test specimens with an Arburg Allrounder 320-210-750 injection moulding machine at defined cylinder temperatures in zones 1 to 4 of 240 to 280° C. and a mould temperature of 100° C.

[0165] Production of the Moulding Compound FM-2 [0166] Composition (1): 42.7% by weight Kraton G1651 (SEBS) [0167] 24.0% by weight Polybond 3200 (PP-g-MAH) [0168] 33.0% by weight plasticiser (Paraffinum Perliquidum) [0169] 0.3% by weight Irganox HP2921 [0170] Composition (II): 99.7% by weight Kraton FG1901 GT (SEBS-g-MAH) [0171] 0.3% by weight Irganox HP2921 [0172] Composition (III): 42.7% by weight Kraton G1651 (SEBS) [0173] 23.0% by weight Polybond 3200 (PP-g-MAH) [0174] 33.0% by weight plasticiser (Paraffinum Perliquidum) [0175] 1.0% by weight Lupasol G20 [0176] 0.3% by weight Irganox HP2921

[0177] The components were compounded in the specified proportions in a twin-screw extruder from Werner and Pfleiderer with a screw diameter of 25 mm at an average zone temperature of 200 to 230° C., a screw speed of 250 rpm and a throughput of 8 kg/h, wherein the SEBS, the PP and the additives were metered into the feed zone, while the plasticiser was metered into the polymer melt via a metering pump through a bore in the cylinder at the level of heating zone 3. The polymer melt was drawn off as a strand from a nozzle with a 3 mm diameter and granulated after cooling with water. The granules were dried for 24 hours at 80° C. in a vacuum of 30 mbar. The test specimens produced with this granulate had a Shore hardness of 80A for the moulding compound FM-2 (I), a Shore hardness of 70 A for the moulding compound FM-2 (II) and a Shore hardness for the moulding compound FM-2 (III) of 78 A.

[0178] Production of the Composite Test Specimen

[0179] The composite test pieces, so-called 2K peel plates made of frames and tabs, were manufactured using an Arburg Allrounder 520A injection moulding machine, equipped with a 30 mm standard three-zone screw. For this purpose, in a first step (i), the frame plate (section (1)) was injection moulded from the moulding compound FM-1 (i.e. the polyamide moulding compounds B1, B2 and VB1 to VB5). 25 seconds after the start of the injection of the frame plate, the slide that kept the cavity for the section (II) occupied during phase (i) was pulled out of the tool. In the second step (ii), the moulding compound FM-2 was then injected into this now vacated cavity and the flexible tab (section (11)) was formed in this way. The injection moulding parameters used are summarised in the table below. The composite test specimen 1 can be seen in FIGS. 1 and 2. The frame has a side length a of 120 mm, a width b of 90 mm and a thickness g of 3 mm, while the tab 4 has a side length e of 150 mm, a width f of 30 mm and a thickness h of 1 mm. The frame 2 contains an opening 3 with a side length c of 55 mm and a width d of 50 mm, which is positioned in the frame 2 such that the overlap of the frame 2 with the tab 4 takes up an area of 50×30 mm.sup.2. The side of the tab 4 remote from the sprue is located above the frame opening 3.

TABLE-US-00005 Moulding Moulding Parameter Unit compound FM-1 compound FM-2 Temperature of cylinder ° C. 40, 260, 270, 40, 180, 190, Zones 0, 1, 2, 3, 4 280, 290 200, 210 Temperature of nozzle ° C. 290 210 Temperature of hot runner ° C. 290 290 Temperature of tool ° C. 100 100 Injection speed mm/s 100 100 Screw speed RPM 80 100 Back pressure bar 100 100 Holding pressure bar 200 300

[0180] Measuring Methods

[0181] Unless otherwise specified, the test specimens were used in the dry state. For this purpose, the test specimens were stored after injection moulding for at least 48 hours at room temperature in a dry environment, i.e. over silica gel.

[0182] The following measurement methods were used for this application:

[0183] Melting Point (Tm) and Enthalpy of Fusion (ΔHm):

[0184] The melting point and enthalpy of fusion were determined on the granulate according to ISO 11357-3 (2013). The DSC (differential scanning calorimetry) measurements were carried out with a heating rate of 20 K/min.

[0185] Glass Transition Temperature, Tg:

[0186] The glass transition temperature T.sub.g was determined in accordance with ISO 11357-2 (2013) 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.

[0187] Relative Viscosity, η.sub.rei:

[0188] 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 (unless otherwise stated), and the calculation of the relative viscosity (RV) according to RV=t/t.sub.0 was based on Section 11 of the standard.

[0189] Tensile Modulus of Elasticity:

[0190] The tensile modulus of elasticity was determined according to ISO 527 (2012) at 23° C. with a tensile speed of 1 mm/min on an ISO tensile rod (type A1, dimensions 170×20/10×4) according to the standard: ISO/CD 3167 (2003).

[0191] Breaking Stress and Elongation at Break:

[0192] The determination of breaking stress and elongation at break were carried out according to ISO 527 (2012) at 23° C. with a tensile speed of 5 mm/min on an ISO tension rod, type A1 (dimensions 170×20/10×4 mm), produced according to the ISO standard/CD 3167 (2003).

[0193] Charpy Impact Strength:

[0194] The Charpy impact strength was determined in accordance with ISO179/2*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).

[0195] Charpy Notched Impact Strength:

[0196] The Charpy notched 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).

[0197] Shore Hardness

[0198] The Shore hardness according to methods A and D was determined using a hardness tester from Karl Franknach according to ISO 7619-1 (2012-02). The arithmetic mean values from 5 measurements are given. The test specimens used had the dimensions 60×60×4 mm and were stored in a dry place at 23° C. until immediately before the test, but for at least 48 hours after production. The measurement was also carried out at 23° C. and the values read off after 15 seconds.

[0199] Adhesion Strength:

[0200] The composite test specimens (2K peel plate) according to FIGS. 1 and 2 for determining the adhesion strength were stored for different times at 70° C. and 62% relative humidity. The test specimens were stored overnight (12 hours) in an air-conditioned environment at 23° C./50% rel. humidity until the roller peel test. Storage for 0 hours means that the composite test specimens produced were stored for 48 hours at room temperature (23° C.) in a dry environment, i.e. over silica gel, after injection moulding. The terms used in the following in connection with the composite test specimen and the holder for the roller peel test refer to FIGS. 1 and 2.

[0201] The adhesion strength was determined by means of a roller peel test at 23° C., in which the 30 mm wide tab 4 (section II) of the composite test specimen 1 used for the measurement was moved over a deflection roller 7 at an angle of 90° using a tensile testing machine peeled from frame 2 (section I) at a tensile speed of 50 mm/min; Table 2 shows the mean value of the mean peel force [N] determined from five individual measurements over the measuring section. The part of the tab remote from the sprue was attached to the upper specimen holder and the holder 6 for the test specimen was attached to the lower specimen holder of the tensile testing machine. The deflection roller 7 used had a diameter of 20 mm. The frame 2 of the composite test body can move freely in the plane perpendicular to the tensile axis Z and is stabilised by means of fixing rollers 8. During the peeling test, the frame 2 was shifted continuously over the entire measuring section in the holder so that the break zone (zone between still adhering and already loosened parts) was always in the plane of the tensile axis Z.

[0202] Discussion of the Results:

[0203] The composite according to the invention with a section (I) made of the polyamide moulding compound B1 and a section (II) made of the moulding compound FM-2 (I) has very good adhesion strength and retains this good adhesion even after five days of storage at 70° C. and 62% relative humidity at almost the same level. In comparison, the adhesion strength of VB4, which, in contrast to B1, is free of component (B), to FM-2 (I) is already 10% lower after manufacture and insufficient after storage. The same picture emerges in a comparison of the composites B2/FM-2 (I) and VB5/FM-2 (I), wherein excellent adhesion can be measured for B2 after production and storage, while there is insufficient adhesion after storage for VB5. Looking now at the adhesion strength to the moulding compound FM-2 (II), the moulding compound B1 according to the invention has excellent adhesion before and after storage, while the adhesion of VB4 is already reduced by a factor of 2.5 after production compared to B1 and turns out to be insufficient after storage. The modification of the polyamide moulding compound with MAH-grafted polyolefins according to the prior art, as represented by the comparative examples VB1 to VB3, does not lead to composites with adequate adhesion. No or only very weak adhesion strength was observed when component (B) was contained in both moulding compounds or in sections (I) and (II) of the composite at the same time.