POLYAMIDE PARTS WITH LOW FUEL PERMEATION

Abstract

Use of a part comprising at least a portion of a polyamide moulding composition said portion for direct contact with fuel,

wherein the polyamide moulding composition consists of the following components in the following proportions: (A) 30-90% by weight of at least one polyamide; (B) 10-70% by weight of fibers with non-circular cross-section; (C) 0-10% by weight of at least one stabiliser; (D) 0-10% by weight of additives different from (B) and (C),
wherein the sum of (A)-(D) makes up 100% of the portion.

Claims

1. Method of using a part comprising at least a portion of a polyamide moulding composition said portion for direct contact with a fuel, wherein the polyamide moulding composition consists of the following components in the following proportions: (A) 30-90% by weight of at least one polyamide; (B) 10-70% by weight of fibers with non-circular cross-section; (C) 0-10% by weight of at least one stabiliser; (D) 0-10% by weight of additives different from (B) and (C), wherein the sum of (A)-(D) makes up 100% of the portion.

2. Method according to claim 1, wherein the polyamide moulding composition has the following proportions: (A) 50-90% or 52-80% by weight of component (A); (B) 10-50% by weight of component (B); (C) 0.05-8% by weight of component (C); (D) 0.01-8% by weight of component (D).

3. Method according to claim 1, wherein component (A) in a major proportion comprises or consists of at least one polyamide with a relative viscosity, measured according to ISO 307:2019 in m-cresol at a concentration of 0.5 weight percent at a temperature of 20 C. of at least 1.5.

4. Method according to claim 1, wherein component (A) is at least one aliphatic or partially aromatic polyamide derived from at least one dicarboxylic acid and at least one diamine or from at least one lactam or ,-amino acid.

5. Method according to claim 1, wherein component (A) consists of at least one lactam-based polyamide based on lactam with at least 8 carbon atoms.

6. Method according to claim 1, wherein the polyamide of component A has an excess of amine end groups.

7. Method according to claim 1, wherein component (B) is selected as glass fibres.

8. Method according to claim 1, wherein the fibres of component (B) have a ratio of cross-sectional major to minor axes in the range between 8 and 2 and/or wherein the length of the major axis is in the range of 15-40 m, and the length of the minor axis is in the range of 4-15 m.

9. Method according to claim 1, wherein component (C) is selected as at least one light stabiliser or at least one heat stabiliser and/or antioxidant.

10. Method according to claim 1, wherein component (D) is selected from the group consisting of non-fibrous fillers electrostatic discharge and/or conductivity additives, flame retardants, pigments, colorants, markers, processing aids including lubricants, intumescent agents, plasticisers, impact modifiers, flow aids, nucleating agents, mould release agents or a combination thereof.

11. Method according to claim 1, wherein the part is an injection moulded part.

12. Method according to claim 1, wherein the fuel is selected as FAM-B, wherein the permeation value of the polyamide moulding composition with respect to FAM-B at 60 C. is below 80 g/(m.sup.2*d); and/or wherein the fuel is selected as E10, wherein the permeation value of the polyamide moulding composition with respect to E10 at 60 C. is below 19 g/(m.sup.2*d); and/or wherein the fuel is selected as E85, wherein the permeation value of the polyamide moulding composition with respect to E85 at 60 C. is below 40 g/(m.sup.2*d).

13. Method according to claim 1, wherein the part takes the form of a connector.

14. Method according to claim 1, wherein the part consists of said polyamide moulding composition.

15. Connector comprising at least a portion of a polyamide moulding composition said portion for direct contact with fuel, wherein the polyamide moulding composition consists of the following components in the following proportions: (A) 30-90% or 50-90% by weight of at least one polyamide; (B) 10-70% or 10-50% by weight of fibers with non-circular cross-section; (C) 0-10% by weight of at least one stabiliser; (D) 0-10% by weight of additives different from (B) and (C), wherein the sum of (A)-(D) makes up 100% of the portion.

16. Method according to claim 1, wherein the polyamide moulding composition has the following proportions: (A) 52-80% by weight, or 55-75% by weight, to 60-70% by weight of component (A); (B) 15-45% by weight, or 20-40% by weight, or 25-35% by weight of component (B); (C) 0.1-5% by weight, or 0.15-2% by weight of component (C); (D) 0 0.1-5% by weight, or 0.5-3% by weight of component (D).

17. Method according to claim 1, wherein component (A) in a major proportion comprises or consists of at least one polyamide with a relative viscosity, measured according to ISO 307:2019 in m-cresol at a concentration of 0.5 weight percent at a temperature of 20 C. of at least 1.6, or of at least 1.7, or of at least 1.8 or at least 1.9.

18. Method according to claim 1, wherein component (A) is at least one aliphatic or partially aromatic polyamide derived from at least one dicarboxylic acid and at least one diamine or from at least one lactam or ,-amino acid, wherein component (A) is selected from at least one of polyamide 6, polyamide 12, polyamide 11, polyamide 6/12, polyamide 6/66, and/or is derived from at least one aliphatic or aromatic dicarboxylic acid, including those selected from the group consisting of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, brassylic acid, thapsic acid, octadecanedioic acid, terephthalic acid, isophthalic acid, or a combination thereof and from at least one aromatic, aliphatic or cycloaliphatic diamine selected from the group consisting of: an aliphatic, non-linear or linear diamine with 4-10, or 4-8, or 6 carbon atoms, 1,3-bis(aminomethyl)cyclohexane (1,3-BAC), 1,4-bis(aminomethyl)cyclohexane (1,4-BAC), bis(4-aminocyclohexyl)methane (PACM), isophoronediamine (IPD), bis(3-methyl-4-aminocyclohexyl)methane (MACM), m-xylylenediamine (MXDA), p-xylylenediamine (PXDA) or a combination thereof.

19. Method according to claim 1, wherein component (A) is at least one aliphatic or partially aromatic polyamide derived from at least one dicarboxylic acid and at least one diamine or from at least one lactam or ,-amino acid, wherein component (A) is selected from the group consisting of the following polyamides: 12, 46, 66, 410, 610, 612, 614, 416, 616, 618, 6I/6T, 6T/6I, 56, 510, 512, 514, 516, 518, 1010, 1012, 1014, 1016, 1018, MACM12, PACM12, MACM14, PACM14, MACMI/12, 6I/6T/612/MACMI/MACMT/MACM12, MACMI/MACMT/12, 6I/6T/MACMI/MACMT/PACMI/PACMT/12, 4T, 5T, 6T, 9T, 10T, 12T, 6T/6I, 6T/66, 6T/12, 6T/612, 6T/10T, 10T/12, 10T/612, 10T/11, 1012/10T, 1212/10T, 1212/6T, 1010/6T, or a mixture thereof.

20. Method according to claim 1, wherein component (A) consists of at least one lactam-based polyamide based on lactam with at least 10 carbon atoms, or 12 carbon atoms, and/or wherein component (A) primarily or completely consists of a lactam-based polyamide with a relative viscosity of at least 1.9, or is a blend of such lactam-based polyamides comprising at least one lactam with a relative viscosity of at least 1.9 measured according to ISO 307:2019 in m-cresol at a concentration of 0.5 weight percent at a temperature of 20 C.

21. Method according to claim 1, wherein the polyamide of component A has an excess of amine end groups, wherein there is a concentration of amino groups in the range of 30-90 mmol/kg, or wherein the concentration of amine end groups is in the range of 40-60 mmol/kg.

22. Method according to claim 1, wherein component (B) is selected as glass fibres, selected from E glass, A glass, C glass, D glass, M glass, S glass, R glass or mixtures thereof, including fibres which are provided with a sizing, including an aminosilane sizing.

23. Method according to claim 1, wherein the fibres of component (B) have a ratio of cross-sectional major to minor axes in the range between 6 and 2, or between 5 and 3 and/or wherein the length of the major axis is in the range of 20-35 m, and the length of the minor axis is in the range of 5-10 m.

24. Method according to claim 1, wherein component (C) is selected as at least one light stabiliser or at least one organic heat stabiliser and/or antioxidant, including at least one organic stabiliser based on sterically hindered phenols and/or phosphonites, selected from the group consisting of N,N-hexamethylene-bis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionamide, bis-(3,3-bis-(4-hydroxy-3-tert-butylphenyl)-butanoic acid)-glycol ester, 2,1-thioethylbis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate, 4,4-butylidene-bis-(3-methyl-6-tert-butylphenol), ethylene bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate], triethyleneglycol-3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, adducts from phenylenediamine with acetone, adducts from phenylenediamine with linolene, N,N-dinaphthyl-p-phenylenediamine, N-phenyl-N-cyclohexyl-p-phenylenediamine or mixtures of two or more thereof, stabilisers from the group of phosphites and phosphonites, including triphenylphosphite, diphenylalkylphosphite, phenyldialkylphosphite, tris(nonylphenyl)phosphite, trilaurylphosphite, trioctadecylphosphite, distearylpentaerythritoldiphosphite, tris(2,4-di-tert-butylphenyl)phosphite, diisodecylpentaerythritoldiphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritoldiphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)-pentaerythritoldiphospite, diisodecyloxypentaerythritoldiphospite, bis(2,4-di-tert-butyl-6-methylphenyl) pentaerythritoldiphosphite, bis(2,4,6-tris-(tert-butylphenyl))pentaerythritol-diphosphite, tristearylsorbitoltriphosphite, tetrakis(2,4-di-tert-butylphenyl)-4,4-biphenylenediphosphonite, 6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenz-[d,g]-1,3,2-dioxaphosphocine, 6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenz[d,g]-1,3,2-dioxaphosphocine, bis(2,4-di-tert-butyl-6-methylphenyl)methylphosphite and bis(2,4-di-tert-butyl-6-methylphenyl)ethylphosphite, tris[2-tert-butyl-4-thio(2-methyl-4-hydroxy-5-tert-butyl)-phenyl-5-methyl]phenyl-phosphite and tris(2,4-di-tert-butylphenyl)phosphite, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazian-2-ylamino)phenol, triethyleneglycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, tetrakis-methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)methane, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 2,2-methylenebis-(6-tert-butyl-p-cresol)monoacrylate and mixtures thereof.

25. Method according to claim 1, wherein component (D) is selected from the group consisting of non-fibrous fillers, electrostatic discharge and/or conductivity additives chosen from the group consisting of carbon black, carbon nanotubes, carbon fibres, graphene, graphite, and mixtures thereof, flame retardants, pigments, colorants, markers, processing aids including lubricants, intumescent agents, plasticisers, impact modifiers, flow aids, nucleating agents, mould release agents or a combination thereof.

26. Method according to claim 1, wherein the fuel is selected as FAM-B, wherein the permeation value of the polyamide moulding composition with respect to FAM-B at 60 C. is below 75 g/(m.sup.2*d) or in the range of 60-75 g/(m.sup.2*d); and/or wherein the fuel is selected as E10, wherein the permeation value of the polyamide moulding composition with respect to E10 at 60 C. is below 18 g/(m.sup.2*d) or in the range of 12-17 g/(m.sup.2*d) and/or wherein the fuel is selected as E85, wherein the permeation value of the polyamide moulding composition with respect to E85 at 60 C. is below 55 g/(m.sup.2*d) or in the range of 25-33 g/(m.sup.2*d).

27. Method according to claim 1, wherein the part takes the form of a welded connector, a quick fix connector, including for the automotive field as a fuel-line connector.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0099] Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

[0100] FIG. 1a-c) shows a schematic representation of the permeation measurement setup, wherein in FIG. 1a) the container is shown, in FIG. 1b) the specimen plate and in FIG. 1c) the ring.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0101] The parts of the invention are moulded bodies that are made using a moulding composition that comprises or consists of: [0102] (A) at least one polyamide; [0103] (B) glass fibres with a non-circular cross section; [0104] (C) at least one component chosen from additives, modifiers and moulding aids.

[0105] In the working examples the materials according to table 1 were used.

TABLE-US-00001 TABLE 1 materials used Commercial products Supplier A1 PA12 Polyamide 12, EMS-CHEMIE AG, .sub.rel = 1.64-1.69 Domat/Ems, Switzerland A2 PA12 Polyamide 12, EMS-CHEMIE AG, .sub.rel = 1.85-1.95 Domat/Ems, Switzerland A3 Transparent MACMT/MACMI/12 EMS-CHEMIE AG, copolyamide (38/38/24 mol-%), Domat/Ems, Switzerland .sub.rel = 1.51-1.57 B1 Flat Glass fibres, E- CSG3PA-820, length 3 NITTO BOSEKI, Japan Glass mm, main axis length 28 m, minor axis length 7 m, axis ratio = 4, silane sizing B2 Round Glass fibres, 995 EC10-4.5, length European Owens Corning E-Glass 4.5 mm, round cross Fiberglas SPRL, Belgium section, diameter 10 m, silane sizing C1 Stabiliser SANDOSTAB P-EPQ Clariant Plastics & Coatings (Deutschland) GmbH, Germany C2 Processing Magnesium stearate AV Brlocher GmbH, Germany aid/lubricant C3 Antioxidant HOSTANOX O 3 P Clariant Produkte (Deutschland) GmbH, Germany C4 Colorant (black PA12 MB L20 SCHWARZ EMS-CHEMIE AG, masterbatch) N115/25 Domat/Ems, Switzerland

[0106] Moulding compositions for all examples were produced in a FEDDEM FED 26 twin-screw extruder from FEDDEM GmbH & Co. KG. Compositions as listed in Table 2 were compounded, adding component (B) by the side feeder.

TABLE-US-00002 TABLE 2 compositions B1 B2 B3 VB1 A1 wt % 69.1 30.0 69.1 A2 wt % 67.9 A3 wt % 19.1 B1 wt % 30 50 30 B2 wt % 30 C1 wt % 0.2 0.2 0.2 0.2 C2 wt % 0.2 0.2 0.2 0.2 C3 wt % 0.5 0.5 0.5 0.5 C4 wt % 1.2

Test Parts:

[0107] The compounded compositions were injection moulded (Aarburg Allrounder, tool temperature 80 C.) to produce specimens appropriate for the testing. For permeation tests, the test parts were 100100 mm with 1 mm thickness. For mechanical and tensile tests, the test parts were according to ISO 527, ISO 179/1eA, ISO 179/1eU.

Test Methods:

Permeation Tests:

[0108] Permeation was measured with the following liquids: [0109] FAM-B, a methanol-containing simulated fuel (Liquid 2, DIN 51604); [0110] E10 (DIN 51626); [0111] E85 (ASTM 5798)

[0112] Permeation values were determined at either 20 C. or 60 C. in a manner in corresponding to DIN 53122-1.

[0113] 50 millilitres of the required fluid was added to an aluminium container 1 as depicted in FIG. 1a) with inner diameter of 80 mm and outer diameter of 100 mm and a depth of 21.5 mm. The container includes 8 M4-threaded holes 4.

[0114] As test specimens, 1001002 mm plates 2 of the material to be tested were injection moulded and drilled with holes 5 to align with the holes 4 of the aluminium container 1 (FIG. 1b). An aluminium ring 3 (FIG. 1c) with inner diameter of 80 mm and outer diameter of 100 mm with 4.2 mm holes 6 to align with the drilled holes 5 of the injection-moulded plate was placed over the plate 2. The orientation of the system was such that the aluminium containers 1 remain under the plate 2 at all times.

[0115] The container was filled with 50 millilitres of the required fluid and sealed by screwing the ring 3 onto the plate 2 into place on the aluminium container 1. The closed system was then placed into an oven, for elevated temperature measurements (as reported in Table 4). Permeation was measured gravimetrically at regular intervals until a continuous, linear change in weight of the test specimen was established.

[0116] Tensile modulus, tensile strength at break elongation at break and energy at break: were measured according to ISO 527 at a tensile speed of 1 mm/min on an ISO 3167 compliant tensile bar. The values for dry were obtained on samples as moulded. The values for conditioned (cond.) were obtained from samples that were conditioned in accordance with ISO 527-1 (2019) with reference to ISO 291 (2008), storing specimens for 16 hours at 232 C. at 5010% relative humidity.

[0117] HDT A (1.8 MPa) and HDT C (8 MPa): ISO 75:2013, ISO impact specimen, 80*10*4, dry. Mold shrinkage: Measured according to ISO 294-4 (2018) on 606020 mm specimens. Longitudinal and transverse values are reported.

[0118] Relative viscosity: DIN EN ISO 307 (2007), in 0.5 weight percent m-cresol solution at a temperature of 20 C.

[0119] Thermal behaviour (melting point Tm and glass transition temperature (T.sub.g): ISO standard 11357-1 (2016), -2 (2013) and -3 (2011), measured on granules, where the differential scanning calorimetry (DSC) is performed at a heating rate of 20 C./min.

[0120] Charpy impact strength and notched impact strength: Measured according to ISO 179/keU or ISO 179/keA on the ISO test rod, standard ISO/CD 3167, type B1, 80104 mm at a temperature of 23 C.

[0121] The results of the thermal, thermomechanical and mechanical tests are given in Table 3 and the results of the permeation tests are given in Table 4.

TABLE-US-00003 TABLE 3 thermal, thermomechanical and mechanical test results Norm Unit B1 B2 B3 VB1 Rel. viscosity DIN EN 1.83 1.79 1.961 1.833 (0.5%, m-cresol, ISO 307 20 C.) (2007) Tm ISO 11357 C. 179 178 177 178.8 Tg ISO 11357 C. 29 31 31 27.2 Tensile modulus 5 mm/min, MPa 7027 7770 7640 6913 dry Tensile strength 5 mm/min, MPa 116 133 126 110 at break dry Elongation at 5 mm/min, % 4.2 4.1 3.3 5.5 break dry Energy of break 5 mm/min, J 10.9 12.2 8.8 14.5 dry Tensile modulus 5 mm/min, MPa 6035 7580 6760 5990 cond. Tensile strength 5 mm/min, MPa 100 125 105 99 at break cond. Elongation at 5 mm/min, % 4.7 3.9 3.3 6.1 break cond. Energy of break 5 mm/min, J 10.8 10.6 7.6 14.2 cond. Charpy ISO 179-2: kJ/m.sup.2 74 74 66 83 impact 30 1997 C., dry Charpy ISO 179-2 kJ/m.sup.2 87 82 66 96 impact 23 C., dry Charpy ISO 179-2 kJ/m2 70 73 59 77 impact, 23 C., cond. Notched Charpy ISO 179-2 kJ/m.sup.2 26.7 12.5 17.2 25.4 impact 30 C., dry Notched Charpy ISO 179-2 kJ/m.sup.2 20.9 17.3 13.7 18.8 impact 23 C., dry Notched Charpy ISO 179-2 kJ/m2 22.7 15.7 16.2 23.3 impact, 23 C., cond. HDT A (1.8 MPa) ISO 75 C. 155 160 163 149 HDT C (8 MPa) ISO 75 C. 82 84 114 73 Linear mold 24 h, dry % 0.11 0.09 0.23 0.1 shrinkage long. Linear mold 24 h, dry % 0.34 0.29 0.48 0.52 shrinkage trans. Linear mold 14 d, dry % 0.1 0.08 0.2 0.08 shrinkage long. Linear mold 14 d, dry % 0.33 0.25 0.44 0.48 shrinkage trans.

TABLE-US-00004 TABLE 4 permeation test results Norm State Unit B1 B2 B3 VB1 Permeation FAM B, dry g/(m.sup.2*d) 64.64 71.0 74.5 87.4 (liquid) 60 C. Permeation E10, dry g/(m.sup.2*d) 15.2 16.4 19.1 (liquid) 60 C. Permeation E85, dry g/(m.sup.2*d) 30.2 31.7 41 (liquid) 60 C.

Discussion of Results

[0122] As is evident from the data shown in Table 4, inventive examples 1B1-1B3 demonstrate a desirable reduction in permeability to FAM B when compared with comparative example VB1 with round glass fibre reinforcement. The inventive examples B1 and B3 furthermore show a low permeability of test fuels E10 and E85 when compared with the round-glassfibre reinforced comparative example VB1. The mechanical properties of all inventive and comparative examples are reasonable, as would be expected from materials with glass reinforcement loadings of 30% by weight. The use of flat glass fibres in the moulding composition used in the invention has the unexpected effect of reducing permeation in while providing the connector with an equivalent degree of reinforcement as may be expected from glass fibres with circular cross section.