COMPOSITE

Abstract

The invention relates to a directly adhering composite composed of at least one part composed of at least one polyamide molding compound and at least one part composed of at least one elastomer, preferably obtainable from rubber to be vulcanized or crosslinked with elemental sulfur, wherein at least one part comprises the mixture of polyoctenamer and polybutadiene.

Claims

1. A mixture of polyoctenamer and polybutadiene.

2. The mixture as claimed in claim 1, wherein the polybutadiene has a number-average molecular weight Mn of 800 to 20,000 g/mol and/or a dynamic viscosity, measured by the cone-plate method to DIN 53019 at standard pressure and at a temperature of 25° C., of 100 to 15,000 mPas.

3. A directly adhering composite composed of at least one part produced from at least one polyamide molding compound and at least one part produced from at least one elastomer, wherein at least one part comprises the mixture as claimed in claim 1.

4. The composite as claimed in claim 3, wherein the composite comprises the mixture in the part produced from the polyamide molding compound.

5. The composite as claimed in claim 3, characterized in that the polyamide molding compound comprises, to an extent of at least 30% by weight, a mixture of a) 60 to 99.9 parts by weight of polyamide and b) 0.1 to 40 parts by weight of polyoctenamer and polybutadiene, wherein the sum total of the parts by weight of a) and b) is 100 in the polyamide molding compound, and the elastomer part is produced from rubber to be crosslinked or vulcanized with elemental sulfur as crosslinking agent.

6. The mixture as claimed in claim 1, wherein the polyoctenamer is 1,8-trans-polyoctenamer.

7. The composite as claimed in claim 3, wherein the polybutadiene has a number-average molecular weight Mn of 800 to 20,000 g/mol and/or a dynamic viscosity, measured by the cone-plate method to DIN 53019 at standard pressure and at a temperature of 25° C. in the range from 100 to 15,000 mPas, preferably in the range from 550 to 4500 mPas, is used.

8. The composite as claimed in claim 5, wherein the rubber to be crosslinked with elemental sulfur as crosslinking agent is selected from the group consisting of natural rubber, ethylene-propylene-diene rubber, vinylaromatic/diolefin rubber, polybutadiene rubber, polyisoprene, butyl rubber, halobutyl rubber, nitrile rubber, hydrogenated nitrile rubber, carboxylated butadiene/acrylonitrile rubber, and polychloroprene.

9. The composite as claimed in claim 8, wherein the vinylaromatic/diolefin rubber is styrene/butadiene rubber.

10. The composite as claimed in claim 8, wherein the halobutyl rubber is chloro- or bromobutyl rubber.

11. The composite as claimed in claim 3, wherein the polyamide is PA6 or PA66.

12. The composite as claimed in claim 3, wherein the polyamide is PA6 and the rubber to be crosslinked with sulfur used is ethylene-propylene-diene rubber.

13. The composite as claimed in claim 3, wherein the polyoctenamer and polybutadiene are in a mass ratio of 1 part polyoctenamer:20 parts polybutadiene to 30 parts polyoctenamer:1 part polybutadiene.

14. The composite as claimed in claim 3, wherein the composite does not need any additional adhesion promoter.

15. A product comprising the at least one composite as claimed in claim 3.

16. The product as claimed in claim 15, characterized in that it is a seal, membrane, gas pressure storage means, hose, housing for a motor, pump or electrically operated tool, roller, tire, coupling, buffer stop, conveyor belt, drive belt, multilayer laminate or multilayer film, or a sound- and vibration-dampening component.

17. A process for producing a directly adhering composite composed of at least one part produced from at least one polyamide molding compound and at least one part produced from at least one elastomer by at least one shaping method from the group of extrusion, flat film extrusion, film blowing, extrusion blow molding, coextrusion, calendering, casting, compression methods, injection embossing methods, transfer compression methods, transfer injection compression methods or injection molding or special methods thereof, either by contacting the part composed of the polyamide molding compound with a rubber component and exposing it to the vulcanization conditions of the rubber, or by contacting the part composed of rubber with a polyamide molding compound, with at least the molding compound or a part, preferably the polyamide molding compound, comprising the mixture of polyoctenamer and polybutadiene.

18. The use of a mixture of polyoctenamer and polybutadiene for production of a directly adhering composite composed of at least one part composed of at least one polyamide molding compound and at least one part composed of at least one elastomer, characterized in that the mixture is used in the molding compound of at least one part, preferably in the polyamide molding compound.

19. The composite as claimed in claim 3, wherein the polyoctenamer is 1,8-trans-polyoctenamer.

Description

EXAMPLES

1. Polyamide Components Used:

[0225] The compositions of the polyamide components are summarized in Table 1.

[0226] The constituents of the polyamide components are stated in parts by mass based on the overall molding composition.

TABLE-US-00001 TABLE 1 Composition of the polyamide molding composition for the polyamide- based component of the composite Polyamide component 1 2 3 4 5 Constituent A 95 95 95 95 95 Constituent B 5 0 1 2.5 4 Constituent C 0 5 4 2.5 1 Sum total of the 5 5 5 5 5 proportions by mass of constituents B and C

[0227] Product names and manufacturers of the constituents of the polyamide components in Table 1: [0228] Constituent A=Durethan® BKV30 H2.0 901510 from LANXESS Deutschland GmbH, Cologne, with ISO molding compound designation ISO 1874-PA6, GHR, 14-090, GF 30, a heat-stabilized nylon-6 with 30% added glass fibers [0229] Constituent B=polyoctenamer, Vestenamer® 8012 (1,8-trans-polyoctenamer), 80% trans, weight-average molecular weight Mw 90 000 g/mol, T.sub.m=54° C., 30% crystalline (manufacturer data), from Evonik Industries AG, Marl [0230] Constituent C=polybutadiene, LBR-307B (liquid polybutadiene) having a dynamic viscosity at 25° C. (DIN 53019) of 2210 mPas and a weight-average molecular weight Mw in the region of 8000 g/mol (manufacturer data) from Kuraray Europe GmbH, Hattersheim am Main

Production of the Polyamide Components in Table 1:

[0231] The constituents of the polyamide components 1 to 5 according to table 1 were mixed to give polyamide molding compounds in a Leistritz ZSE 27 MAXX twin-screw extruder from Leistritz Extrusionstechnik GmbH, Nuremberg. For all the polyamide components, the compounding was conducted at a melt temperature of 260 to 300° C. and with a throughput of 8 to 60 kg/h. The melt was discharged as a strand into a water bath and then pelletized. After compounding, the polyamide molding compounds were dried at 80° C. in a dry air dryer for 4 hours before they were then processed in an injection molding operation.

[0232] Table 2 lists the resulting mass ratios of polyoctenamer to polybutadiene for the polyamide components 1 to 5.

TABLE-US-00002 TABLE 2 Mass ratios of polyoctenamer to polybutadiene of polyamide components 1 to 5 Polyamide component 1 2 3 4 5 Parts of polyoctenamer 5 0 1 1 4 Parts of polybutadiene 0 5 4 1 1

2. Elastomer Components Used:

[0233] The compositions of the rubber mixtures of the elastomer components that result after vulcanization are summarized in Table 3.

[0234] The rubber mixture constituents of the elastomer components are stated in parts by mass based on 100 parts by mass of rubber.

TABLE-US-00003 TABLE 3 Composition of the rubber mixtures of the elastomer components that result after vulcanization Elastomer component A Keltan ® 2450 100 N550 60 PEG-4000 5 Sunpar ® 2280 5 Stearic acid 3 ZnO 5 Sulfur 0.7 TBBS 1 TBzTD-70 3.5

[0235] Product names and manufacturers of the rubber mixture constituents in Table 2: [0236] Keltan® 2450=ethylene-propylene-diene rubber (EPDM) from LANXESS Deutschland GmbH, Cologne [0237] N550=Corax® N550 industrial carbon black from Orion Engineered Carbons GmbH [0238] PEG-4000=polyethylene glycol, CAS No. 25322-68-3, plasticizer from Carl Roth GmbH & Co. KG, Karlsruhe [0239] Sunpar® 2280=paraffinic plasticizer oil from Schill & Seilacher “Struktol” GmbH, Hamburg. The composition is specified by SUNOCO as a mixture of carefully refined paraffinic oils, CAS No. 64742-62-7/64742-65-0. [0240] Stearic acid=Edenor® ST4A stearic acid from BCD-Chemie GmbH, Hamburg [0241] ZnO=Zinkweiss Rotsiegel zinc oxide from Grilio-Werke AG, Goslar [0242] Sulfur 90/95 ground sulfur as vulcanizing agent from SOLVAY GmbH, Hanover [0243] TBBS=Vulkacit NZ vulcanization accelerator from LANXESS Deutschland GmbH, Cologne, CAS No. 102-06-7. [0244] TBzTD-70=Rhenogran® TBzTD-70 polymer-bound vulcanization accelerator from Rhein Chemie Rheinau GmbH, Mannheim, contains tetrabenzylthiuram disulfide CAS No. 10591-85-2.

[0245] The rubber mixtures were produced by means of a Werner & Pfleiderer GK 5E laboratory internal mixer.

3. Production of the Composite Specimens from Polyamide Component and Elastomer Component by Means of 2-Component Injection Molding:

[0246] To detect the rise in bond strength through the inventive combination of materials, composite specimens were produced in a multicomponent injection molding process. An Engel Combimelt 200H/200L/80 2-component injection molding machine from Engel Austria GmbH, Schwertberg, Austria was used, and the injection mold used was a 2-cavity turntable mold.

[0247] The 2K injection molding process was operated in two stages, i.e. first production of the polyamide component by injection molding, dry and dust-free storage of the polyamide component for 24 h and reinsertion of the polyamide component into the elastomer mold cavity of the 2K injection molding machine for overmolding with the rubber component, and subsequent vulcanization. The polyamide component was preheated to the elastomer mold temperature for 20 min prior to reinsertion into the mold.

[0248] In the thermoplastic cavity of the injection mold, a 60 mm*68 mm*4 mm PA sheet was produced by injection molding. The rubber cavity had the dimensions 140 mm*25 mm*6 mm and formed an overlap with respect to the thermoplastic sheet of 44.5 mm*25 mm.

[0249] The polyamide component of the composite specimens was produced with the following injection molding settings: barrel temperature 270/275/275/270/265° C., injection rate 15 cm.sup.3/s, mold temperature 85° C., hold pressure 450 bar, hold pressure held for 20 s, cooling time 15 s.

[0250] The elastomer component of the composite specimens was produced with the following injection molding settings: barrel temperature 100° C., injection rate 7 cm.sup.3/s, mold temperature 165° C., hold pressure 300 bar, hold pressure held for 90 s, vulcanization time 10 min.

4. Testing of the Composite Specimens from Polyamide Component and Elastomer Component by Means of a Peel Test:

[0251] After storage of the composite specimens based on the compositions of polyamide components 1 to 5 and elastomer component A for at least 24 hours, these were subjected to a 90° peel test to test the bond strength. The peel test was conducted on the basis of DIN ISO 813 using a Zwick Z010 universal tester from Zwick GmbH & Co. KG, Ulm, Germany. In this test, the composite specimen was clamped at an angle of 90° in a tensile tester with a special device to accommodate the thermoplastic component—a polyamide component here—and placed under tensile stress. The pretensioning force was 0.3 N, the testing speed 100 mm/min. The bond strength is obtained from the maximum force measured in N based on the width of the elastomer component of 25 mm.

[0252] The results of the peel tests on the composite specimens of polyamide components 1 to 5 and elastomer component A, i.e. the resulting bond strengths, are summarized in table 4.

TABLE-US-00004 TABLE 4 Results of the peel tests of the composite specimens composed of polyamide component and elastomer component, expressed in the resulting bond strength Elastomer component Polyamide component A 1  7.8 N/mm 2  3.6 N/mm 3 14.5 N/mm 4 17.0 N/mm 5 16.9 N/mm

[0253] The composite specimens composed of polyamide components 1 and 2 exhibited bond strengths of >3 N/mm. The composite specimens composed of polyamide components 3, 4 and 5 had significantly higher bond strengths. The bond strengths here were about twice to five times higher compared to polyamide components 1 and 2.

[0254] In summary, table 4 thus shows that the inventive use of a mixture of polyoctenamer and polybutadiene in the polyamide component significantly increased the bond strength.