High-Performance Polymers in Plastic-Rubber ... - VESTAMID

Contents1 Plastic-Rubber Composites 41.1 _ Hard-Soft Composites ..........................................................................................................................................41.2 _Adhesion without Adhesives ............................................................................................................................... 52 Two Approaches to Plastic-Rubber Composites 62.1_ The Two-Stage Process .......................................................................................................................................62.2 _The One-Stage Process ........................................................................................................................................62.3 _Economy ..............................................................................................................................................................63 List of Compounds 84 Polyphenylene Ether VESTORAN ® 94.1 _Processing ..........................................................................................................................................................114.2 _Chemical Resistance ...........................................................................................................................................115 Polyamides VESTAMID ® 145.1_ Polyphthalamide VESTAMID ® HTplus ................................................................................................................ 145.2_ Polyamide 612 VESTAMID ® D ............................................................................................................................ 156 Examples of Rubber Formulations 186.1_ SBR Formulation for K&K Composites with VESTORAN ® ................................................................................ 186.2_ NR/SBR Formulation for K&K Composites with VESTORAN ® .......................................................................... 196.3 _EPDM Formulation for K&K Composites with VESTORAN ® and VESTAMID ® DX9325 ..................................... 206.4 _XNBR Formulation for K&K Composites with VESTAMID ® D ........................................................................... 216.5 _HNBR Formulation for K&K Composites with VESTAMID ® D, VESTAMID ® HTplus .......................................... 226.6 _FKM Formulation for K&K Composites with VESTAMID ® D, VESTAMID ® HTplus ............................................. 226.7 _AEM Formulation for Plastic-Rubber Composites with VESTAMID ® D, VESTAMID ® HTplus ............................. 23

1 Plastic-Rubber CompositesThe High Performance Polymers Business Line of Evonik manufacturesa line of compounds specially modified for the productionof adhesive-free plastic-rubber composites.This brochure describes the plastic-rubber composite process(K&K process) and the compounds available for it.Like all high-performance plastics from the High PerformancePolymers Business Line, these compounds meet the highestquality standards. Our quality management system is certifiedaccording to ISO 9001:2000 and ISO/TS 16949:2002. Numerouscustomers have tested this quality management systemand confirmed its superiority.1.1 Hard-Soft CompositesWherever rubber components must be fastened or fixed, compositesconsisting of a hard component and an elastomer performwell. They represent an important sector of the rubber industry.Such composites are found in a wide variety ofapplications, for example, as shock-absorbing bearings in thechassis of motor vehicles, buffers or reinforced seals in enginesand machines.Traditionally, hard components consisted of metalcomposites. To reduce weight, particularly in vehicles,more and more metal components are being replacedby suitable plastic parts wherever possible.This has two additional advantages: Plastics do notcorrode and can be efficiently processed into verycomplex moldings by injection molding. However,they must be dimensionally stable at the usual vulcanizationtemperatures of 160–190°C. The manufactureof such complex parts from metal is very expensive.The use of plastics in the design of complexcomponents provides the designer and componentdeveloper with much greater latitude.For the long-term function of composites, particularlyunder dynamic stress, the adhesion between thehard component and the soft component of the compositeis an important criterion. It is usually achievedby adhesives. Combinations of all standard rubber typeswith most metals and simple plastics are possible.Besides additional process steps for applying theadhesives, protective measures against emissions ofthe usual solvents and their environmentally correctdisposal are required.4

4 Polyphenylene Ether VESTORAN ® 9VESTORAN ® is the registered trademarkof Evonik for compounds based on poly-2,6-dimethyl-1,4-phenylene ether (PPE).The amorphous material has high heat deflectiontemperature. Moldings ofVESTORAN ® have very low mold shrinkageand warpage. VESTORAN ® is hotwater-resistant. The water absorption isvery low. It is resistant to alkalis and acidsbut less resistant to fats, oils and fuels.Section 4.2 provides details on chemicalresistance.Four VESTORAN ® grades are availablefor adhesive-free plastic-rubbercomposites:• VESTORAN ® 1900 natural and1900 black• VESTORAN ® 1900GF20 light ivoryand 1900GF20 blackThese grades can be combined with SBRand SBR blends, such as NR/SBR; theSBR portion should be at least 20 wt%.These rubbers are to be crosslinked withsulfur. Applications of such combinationsinclude vibration bushings and shock absorbersin the chassis of motor vehicles.Combinations with EPDM compoundsthat are peroxidically crosslinked performwell. Examples of applications are reinforcedprofiles and seals.Examples of SBR, NR/SBR and EPDMformulations are shown in Chapter 7.Figure 4Molecular structure of polyphenylene ether

Table 3: Properties of polyphenylene ether compounds for plastic-rubber compositesProperties Test method UnitVESTORAN ®1900Physical, thermal and mechanical propertiesDensity 23°C ISO 1183 g/cm 3 1.04 1.19Melt volume-flow rate (MVR) 300°C/21.6 kg ISO 1133 cm 3 /10 min ca. 40 ca. 15Tensile test ISO 527-1/-2Stress at yield MPa 60Strain at yield % 6Tensile strength MPa 110Strain at break % >50 3Tensile modulus ISO 527-1/-2 MPa 2000 5600Flexural modulus ISO 178 MPa 2400 5700CHARPY impact strength* 23°C ISO 179/1eU kJ/m² 250 P 50 CCHARPY notched impact strength* 23°C ISO 179/1eA kJ/m² 25 C 12 CTemperature of deflection under load ISO 75-1/-2Method A 1.8 MPa °C 170 185Method B 0.45 MPa °C 190 190Vicat softening temperature ISO 306Method A 10 N °C 190 200Method B 50 N °C 185 190Flammability acc. UL94 0.8 mm ISO 60695 HB HB1.6 mm HB HBWater absorption 23°C, saturation ISO 62 % 0.4 0.4Processing shrinkageDeterminedon 2 mmin flow direction % approx. 0.9 0.5sheets within transverse direction % approx. 0.8 0.6film gate atrim, moldtemperature80°CVESTORAN ®1900GF20Electrical PropertiesRelative permittivity 100 Hz IEC 60250 2.6 2.91 MHz 2.9 2.7Dissipation factor 100 Hz IEC 60250 8 • 10 -4 8 • 10 -41 MHz 16 • 10 -4 18 • 10 -4Electric strength K20/P50 IEC 60243-1 kV/mm 40 33Comparative tracking index IEC 60112Test solution A CTI 225 200100 drops value 200 175Volume resistivity IEC 60093 Ohm • m 10 13 10 13Surface resistance R OA IEC 60093 Ohm 10 14 10 13Electrolytic corrosion IEC 60426 Stage A1 A110

4.1 Processing VESTORAN ®Pre-dryingAlthough VESTORAN ® absorbs very littlemoisture, pre-drying in a circulating orvacuum dryer is extremely important.To prevent damage to the material, dryingconditions should not exceed 110–120°Cfor 2 hours. The pre-dried granulatemust be introduced hot into the machinehopper. The dwell time of the melt in thecylinder should be less than 5 minutes.Machine parametersScrew: L/D ratio min. 20:1, compres -s ion ratio 2:1 to 3:1Nozzle: Diameter greater than 3 mmInjection pressure: 800–1600 barHolding pressure: 50–80% of injectionpressureSpecific back pressure: 5–10 barTemperature settings:Cylinder: 280/300/320/320°CNozzle: 310°CMelt: 300–330°CThe melting temperature should not exceed340°C to prevent thermal damageto the PPE.MoldExternally heated hot runner systemsmust be used. Approximately 0.05 mmdeep venting channels should be placednear the welding lines.Temperature settings for separate manufactureof the moldings (two-stage process):VESTORAN ® 1900 80–90°CVESTORAN ® 1900GF20 130–140°CTemperature settings for theone-stage process:VESTORAN ® 1900 180°CVESTORAN ® 1900GF20 180°CThe higher mold temperature in the onestageprocess enables the molding heat tobe utilized for a shorter vulcanization timeof the rubber component. An exhaustingdevice above the injection molding machineis strongly recommended.Handling VESTORAN ® moldings in thetwo-stage processWhen pre-molded components are usedfor the plastic-rubber composites, nomold release agents may be used. TheVESTORAN ® surfaces must be free ofgrease and dust. Intermediate storage ofthe moldings is done in the dark, for example,in black polyethylene bags. Furtherprocessing within two weeks is recommended.Contaminated surfaces can becleaned by wiping them off with toluene.11

4.2 Chemical Resistance of VESTORAN ®The stress cracking susceptibility test according to ISO 4599under the influence of different media is a criterion for chemicalresistance (bent strip test, 3.5% outer fiber strain withbasic grades; 2.7% outer fiber strain in the case of glassfiber-reinforced grades). The resistance is dependent ontemperature but also on the stress state of the test specimen.Therefore, we recommend using a test under field conditionsto determine whether the requirements are met.12

5 Polyamides VESTAMID ® Figure 5Evonik manufactures and sells various polyamide (PA) grades. The polyamide 612 products are named VESTAMID ® D, the polyphthalamide(PPA) grades are supplied under the trade name VESTAMID ® HTplus.5.1 PolyphthalamideVESTAMID ® HTplusVESTAMID ® HTplus belongs to the familyof polyphthalamide (PPA) polymers.Evonik have combined high temperaturedurability, excellent chemical resistanceagainst the most automotive fluids, andoutstanding mechanical properties withthe flexibility of multiple process technologies.Our latest development exploitsthe high heat deflection temperature ofmore than 280°C and dimensional stabilityof VESTAMID ® HTplus, especially inthe range of 120 to 140°C, and adds thespecial functionality of direct bonding toa variety of elastomers. Compared withPA 66 and PA 612, VESTAMID ® HTplusfeatures also higher strength and stiffness,especially in contact with moisture,a high long-term heat resistance up to150°C, and a low tendency to creep.Due to higher heat deflection temperatureof PPA compared to PA 612 it is possibleto vulcanize also thin thermoplasticparts together with rubber up to 190°Cwithout any deformation of the plasticpart.For direct rubber bonding threeheat- stabilized grades are available:• VESTAMID ® HTplus R1033 and R1133are 30% glass fiber-reinforced,• VESTAMID ® HTplus R1035 contains50% glass fibers.These compounds are especially formanu facturing parts sub jected to hightemperature.Moleculare structure of polyphthalamideTable 5: Properties of VESTAMID ® HTplus compounds for plastic-rubber compositesProperty Test method Unit R1033 R1133 R1035Glass fiber content % 30 30 50Density 23°C ISO 1183 g/cm 3 1.43 1.40 1.64Tensile test ISO 527-1/-2Tensile strength MPa 180 140 260Strain at break % 2.0 1.5 1.8Tensile modulus ISO 527-1/-2 MPa 11000 10500 17000CHARPY impact strength *ISO 179/1eU23°C kJ/m 2 45 C 29 C 70 C-40°C kJ/m 2 30 C 23 C 50 CCHARPY notchedISO 179/1eAimpact strength *23°C kJ/m 2 7 C 6 C 12 C-40°C kJ/m 2 7 C 6 C 12 CVicat softening temperature ISO 306Method A 10 N °C 308 300 308Method B 50 N °C 275 275 282Melt temperature °C 330-340 330-340 330-340Mold temperature °C 140-180 140-180 140-180*C = complete break14

5.2 Polyamide 612VESTAMID ® DCompounds are available in the D seriesspecifically for adhesive-free manufactureof plastic-rubber composites. As partiallycrystalline materials, they feature excellentchemical resistance, particularly towardgreases, oils and fuels. Besides verygood sliding friction properties, PA 612compounds show appreciably less waterabsorption than PA 6 or PA 66.Figure 6Molecular structure of polyamide 612Chemical resistanceThe chemical resistance of PA 612 is comparableto that of PA 12. Polyamide 612generally displays outstanding resistanceto fuels, lubricants, greases, oils, andmost industrial solvents. Polar solventscan cause reversible swelling, especiallyat elevated temperatures. This will generallybe connected with a drop in strength(plasticizer effect). In practice, the originalcharacteristics will be restored afterthe solvent has evaporated. Liquids thathave a particularly high affinity to the carbonamidegroups of the polyamides canact as solvents for PA 612 at higher temperatures.Examples are phenols, cresols,benzyl alcohol, and particular chlorohydrocarbons.Due to their low water absorption,PA 612 compounds exhibit verygood resistance to aqueous agents, suchas alkali solutions, saline solutions, andcleaners. Their resistance to aqueousacids is limited, depending on the temperature,time, and concentration. In general,concentrated acids will lead to a moreor less rapid drop in relative molar mass(embrittlement). Concentrated sulfuricacid and formic acid will dissolve PA 612.Rubber combinationsThe properties of the VESTAMID ® gradessuitable for plastic-rubber composites arelisted in Table 6. Compounds with differentglass fiber contents and, in somecases, with impact modification are available.For manufacture of oil-resistant andfuel-resistant seals and moldings, they canbe combined with appropriate rubberblends, for example, based on XNBR rubber,partially saturated HNBR rubber andFPM rubber. Moldings for the two-stageplastic-rubber process should be stored ina dust-free atmosphere and processedwithin three months.Examples for known rubber formulationsare found in Chapter 7.15

Table 6: Properties of VESTAMID ® polyamide 612 compounds for plastic-rubber compositesProperties Test method Unit X7094 blackDX9301 black4% graphitePhysical, thermal and mechanical propertiesDensity 23°C ISO 1183 g/cm 3 1.06 1.09Melting temperature peak temperature ISO 11357 °C 215 2152 nd heatingTemperature of deflection underISO 75-1/-2loadMethod A 1.8 MPa °C 60 85Method B 0.45 MPa °C 150 185Vicat softening temperature ISO 306Method B 50 N °C 185 187Linear thermal expansion 23°C - 55°C ISO 11359longitudinal 10 -4 K -1 1.3transverse 10 -4 K -1 1.1Flammability acc. UL94 1.6 mm IEC 60695 HB3.2 mm HBWater absorption 23°C, saturation ISO 62 % 2.8 2.7Moisture absorption 23°C, 50 % r.F. ISO 62 % 1.0 1.0Mold shrinkageSpecimenin flow direction127.12.7.3.2 mm % 1.3 1.2in transverse directionProcessing acc.ISO 1874-2 % 1.1 1.4Tensile testISO 527-2/1 AStress at yield MPa 60Strain at yield % 5Stress at break MPa 65Strain at break % 8 7Tensile modulus ISO 527-2/1 A MPa 2200 2700CHARPY impact strength* 23°C ISO 179/1eU kJ/m 2 N 115 C-30°C kJ/m 2 N 110 CCHARPY notched impact 23°C ISO 179/1eA kJ/m 2 6 C 4 Cstrength* -30°C kJ/m 2 7 C 3 CElectrical propertiesRelative permittivity 100 Hz IEC 60250 4.41 MHz 3.9Dissipation factor 100 Hz IEC 60250 10 -4 5901 MHz 10 -4 390Electric strength K20/P50 IEC 60243-1 KV/mm 30Comparative tracking index CTI IEC 60112Test solution A50-drop-value100-drop-value > 600Volume resistivity IEC 60093 Ohm . cm 10 14*N = no break, C = complete break16

DX9320 black10% glass fibersDX9322 black15% milled glass fibersX7099 black20% glass fibersDX9321 black20% glass fibersDX9323 black35% glass fibersDX9325 black40% glass fibers1.12 1.17 1.20 1.19 1.33 1.37215 215 210 215 215 212183 114 190 189 196 195201 186 210 208 213 210199 194 205 207 2090.7 1.0 0.5 0.5 0.5 0.50.8 0.6 0.7 0.7 0.8HB HB HB HB HB HBHB HB HB2.6 2.4 2.0 2.0 1.9 1.91.0 0.9 0.8 0.8 0.8 0.81.29 1.92 0.55 0.66 0.35 0.230.97 0.93 1.05 0.88 1.02 0.863882 59 118 115 148 15010 18 5 5 5 43700 3150 5600 5700 8900 940081 C 46 C 80 C 93 C 90 C 100 C96 C 43 C 60 C 106 C 105 C 104 C11 C 4 C 10 C 18 C 22 C 22 C5 C 3 C 7 C 11 C 15 C 16 C4.3 4.3 4.4 4.4 4.83.1 3.1 3.9 3.1 3.6470 430 650 500 610466 493 430 470 32038 39> 600 > 600 > 600 >600600 575 600 57510 14 10 14 10 14 10 14 10 1417

6.2 NR/SBR Formulation for Plastic-Rubber Compositeswith VESTORAN ®Formulation No.: RD 5010NR 80SBR 1500 20Carbon black N 772 (SRF-HM) 59ZnO, RS 4Stearic acid 1.0Antilux ® 600 2Vulcanox ® 4020 (IPPD) 2.0Vulcazit ® CZ (CBS) 0.65Vulcalent ® E 0.2Vulcanox ® HS (TMQ) 1.2Sulfur 4.0ML (1+4) 100°C 67Vulcameter 180°C t 10min 0.5t 90min 2.0Vulcanization 180°C; 4 minHardness 23°C Shore A 60Hardness 75°C Shore A 57Tensile strength MPa 8.7Strain at break % 260Modulus 100% strain MPa 2.1Modulus 200% strain MPa 5.7Modulus 300% strain MPa 11.6Impact resilience 23°C % 49Impact resilience 75°C % 5919

6.3 EPDM Formulation for Plastic-Rubber Composites with VESTORAN ®and VESTAMID ® DX9325Formulation No.: RD 5162Buna EP G 6470 90VESTENAMER ® 8012 10Carbon Black N 539 (FEF-LS) 72Paraffin Oil 51ZnO, RS 5.0Vulcanox ® HS (TMQ) 1.0TRIM/S 1.25Perkadox ® 14/40 5.5ML (1+4) 100°C 46Vulcameter 180°C t 10min 0.65t 90min 5.2Density g/cm 3 0.96Vulcanization 180°C; 20 minHardness 23°C Shore A 64Hardness 75°C Shore A 53Tensile strength MPa 13.4Strain at break % 420Modulus 100% strain MPa 2Modulus 200% strain MPa 5Modulus 300% strain MPa 8.6Impact resilience 23°C % 59Impact resilience 75°C % 61Compression set 22 h; 70°C % 13.320

6.4 XNBR Formulation for Plastic-Rubber Compositeswith VESTAMID ® DFormulation No.:RD 3731 blueNipol ® 1472 (or Chemigum ® NX 775) 100Vulkasil ® C 60Polestar ® 200 (Calc, Clay) 20Vulcanol ® 88 10Titandioxide 3.0Oppasin ® blue 2.0Stearic acid 1.0BDMA 0.8Perkadox ® BC40-B pd 5.0ML (1+4) 100°C 69Vulcameter 180°C t 10min 0.5t 90min 2.8Vulcanization 180°C; 10 minHardness 23°C Shore A 76Hardness 75°C Shore A 72Tensile strength MPa 9.8Strain at break % 400Modulus 100% strain MPa 9.8Modulus 200% strain MPa 6.1Modulus 300% strain MPa 7.7Impact resilience 23°C % 29Impact resilience 75°C % 49Compression set 22 h; 70°C % 1821

6.5 HNBR Formulation for Plastic-Rubber Composites with VESTAMID ® D,VESTAMID ® HTplusFormulation No.: RD 5080/3Zetpole ® 3110 100Carbon black N 550 (FEF) 65Rhenosin ® W-759 10ZnO 2HVA 2 4Perkaox ® 14/40 7ML (1+4) 100°C 122Vulcameter 180°C t 10min 0.9t 90min 2.8Vulcanization 180°C; 5 minHardness 23°C Shore A 77Hardness 75°C Shore A 73Tensile strength MPa 14Strain at break % 117Modulus 100% strain MPa 12.2Impact resilience 23°C % 45Impact resilience 75°C % 58Compression set % 76.6 FKM Formulation for Plastic-Rubber Composites with VESTAMID ® D,VESTAMID ® HTplusFormulation No.: RD 3367Dai EI 100Carbon black N 990 (MT) 15Rhenofit ® D/A 3Innovox ® OH 6ML (1+4) 100°C 109Vulcameter 180°C t 10min 1.4t 90min 4.1Vulcanization 170°C; 10 min, Tempering 175°C; 24hHardness 23°C Shore A 58Hardness 75°C Shore A 52Tensile strength MPa 7.7Strain at break %Modulus 100% strain MPa 1.7Modulus 200% strain MPa 3.5Modulus 300% strain MPa 5.8Impact resilience 23°C % 10Impact resilience 75°C % 5722

6.7 AEM Formulation for Plastic-Rubber Composites with VESTAMID ® D,VESTAMID ® HTplusFormulation No.: RD 70849Vamac ® G 100Naugard ® 445 2Armeen ® 18D 0.5Stearic acid 2Gafac ® RL-210 0.5Carbon black N-774 55DIAK No 1 1.25Diphenylguanidine (DPG) 4ML (1+4) 100°C 16Vulcameter 180°C t 10minVulcanization 177°C; 20 min, Tempering 175°C; 24hHardness 23°C Shore A 68Tensile strength MPa 13.4Strain at break % 2.4Modulus 100% strain MPa 6.4Modulus 200% strain MPa 510t 90min23