ARTICLE COMPRISING A FABRIC LAYER TREATED WITH PARTLY OXIDIZED POLYETHYLENE

Abstract

The present invention relates to an article having an elastic main body based on at least one thermoplastic elastomer or based on a vulcanizate having an article surface provided with a textile cover ply, characterized in that the textile cover ply is treated with partially oxidized polyethylene, and to processes for producing such an article.

Claims

1.-15. (canceled)

16. An article comprising an elastic main body based on at least one thermoplastic elastomer or based on a vulcanizate having an article surface provided with a textile cover ply, wherein the textile cover ply is treated with partially oxidized polyethylene.

17. The article as claimed in claim 16, wherein the textile cover ply is selected from the group consisting of wovens, formed-loop knits, drawn-loop knits, nonwovens and combinations thereof.

18. The article as claimed in claim 16, wherein the textile cover ply comprises a material selected from the group consisting of cellulose, silk, cashmere, horsehair, aramid (AR), polyurethane (PU), polybenzimidazole (PBI), melamine (MEL), polybenzoxazole (PBO), carbon, polyamide (PA), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyacrylic (PAN), acetate (CA), triacetate (CTA), polyvinyl alcohol (PVA), polyamideimide (PAI), polytrimethylene terephthalate (PTT), polyimide (PI), polybutylene terephthalate (PBT), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyester (PES) and combinations thereof.

19. The article as claimed in claim 18, wherein the textile cover ply comprises a material selected from cotton (CO), viscose (CV), PA6.6, PA6, PET, polyurethane or combinations thereof.

20. The article as claimed in claim 16, wherein the elastic main body is an elastic main body based on a thermoplastic polymer or a vulcanizate in the form of a vulcanized rubber mixture containing at least one rubber component and mixture ingredients, wherein the rubber component is selected from the group consisting of ethylene-propylene copolymer (EPM), ethylene-propylene-diene copolymer (EPDM), (partially) hydrogenated nitrile rubber (HNBR), chloroprene rubber (CR), fluororubber (FKM), natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR) and combinations thereof.

21. The article as claimed in claim 20, wherein the rubber component comprises ethylene-propylene copolymer (EPM), ethylene-propylene-diene copolymer (EPDM) or a blend of ethylene-propylene copolymer (EPM) and ethylene-propylene-diene copolymer (EPDM).

22. The article as claimed in claim 16, wherein the article is a band, strap, belt, hose, air spring bellows, expansion joint or a multilayer fabric web.

23. The article as claimed in claim 16, wherein the article is a drive belt, wherein the elastic main body comprises a top ply as the belt backing and a substructure having a force transmission zone, and wherein the top ply and/or the force transmission zone are provided with the textile cover ply.

24. The article as claimed in claim 23, wherein the drive belt is designed as a flat belt, V-belt, V-ribbed belt, toothed belt, clutch belt or elevator belt.

25. The article as claimed in claim 16, wherein the article is a V-ribbed belt, wherein the elastic main body is a vulcanizate based on ethylene-propylene copolymer (EPM), ethylene-propylene-diene copolymer (EPDM) or a blend of ethylene-propylene copolymer (EPM) and ethylene-propylene-diene copolymer (EPDM), and wherein the textile cover ply comprises a drawn-loop knit or formed-loop knit made of cotton.

26. The article as claimed in claim 25, wherein the textile cover ply further comprises an elastane yarn.

27. A process for producing an article comprising an elastic main body based on at least one thermoplastic elastomer or based on a vulcanizate, and having an article surface provided with a textile cover ply, wherein the process comprises: (a) treating a sheetlike textile with partially oxidized polyethylene to provide the textile cover ply; and, (b) applying the textile cover ply to the surface of the elastic main body based on the at least one thermoplastic elastomer or based on the vulcanizate.

28. The process as claimed in claim 27, wherein the treating of the sheetlike textile with partially oxidized polyethylene is carried out by immersing the sheetlike textile in a suspension containing the partially oxidized polyethylene in a concentration of from 20 to 60 g/l.

29. The process as claimed in claim 27, wherein the treating of the sheetlike textile with partially oxidized polyethylene is carried out by immersing the sheetlike textile in an emulsion containing the partially oxidized polyethylene in a concentration of from 20 to 60 g/l.

30. The process as claimed in claim 27, wherein the treating of the sheetlike textile with partially oxidized polyethylene is carried out by spraying the sheetlike textile with a suspension containing the partially oxidized polyethylene.

31. A process for producing an article comprising an elastic main body based on at least one thermoplastic elastomer or based on a vulcanizate, and having an article surface provided with a textile cover ply, wherein the process comprises: (a) providing the article with the elastic main body based on at least one thermoplastic elastomer or based on a vulcanizate, and having a surface of the article provided with the textile cover ply, wherein the textile cover ply is untreated; and, (b) treating the textile cover ply with partially oxidized polyethylene.

32. The process as claimed in claim 31, wherein the treating of the textile cover ply with partially oxidized polyethylene is carried out by immersing the textile cover ply in a suspension containing the partially oxidized polyethylene in a concentration of from 20 to 60 g/l.

33. The process as claimed in claim 31, wherein the treating of the textile cover ply with partially oxidized polyethylene is carried out by immersing the textile cover ply in an emulsion containing the partially oxidized polyethylene in a concentration of from 20 to 60 g/l.

34. The process as claimed in claim 31, wherein the treating of the textile cover ply with partially oxidized polyethylene is carried out by spraying the textile cover ply with a suspension containing the partially oxidized polyethylene.

35. The process as claimed in claim 31, wherein the treating of the textile cover ply with partially oxidized polyethylene is carried out by spraying the textile cover ply with an emulsion containing the partially oxidized polyethylene.

Description

EXAMPLES

[0041] Four different V-ribbed belt types were produced by the molding process, wherein in each case the articles of examples A and B and examples C and D have the same cover plies, substructure mixtures, polyester cords and adhesive layers for the textile coating. The articles of examples A and B utilized the same cotton-elastane knit, but in example B the textile cover ply was provided with 6.5 g/m.sup.2 of oxidized HDPE before being applied to the blank sleeve. Analogously, the articles of examples C and D utilized the same slightly heavier cotton-elastane knit, but for example D the textile cover ply was provided with 8 g/m.sup.2 of oxidized HDPE before being applied to the blank sleeve. The coils were heated in hollow V-ribbed belt molds and parted off as 6PK1378 belts (see ISO 9982). The belts of types A and B differed from types C and D not only in the textile coatings but also in the rubber mixtures (vulcanizates) and in the profile depths, which in turn was apparent from the belt heights. The employed rubber mixtures (referred to in the table below as EPDM1 and EPDM2) were peroxidically crosslinked EPDM mixtures having different formulations, i.e. different filler contents and degrees of crosslinking.

[0042] Belt types A, B, C, D were then tested for durability and heat aging on a hot bending fatigue life test rig, a visual inspection of the belt being carried out daily. In this test, V-ribbed belts normally exhibit first cracks and then chunk outs after a certain running time. The test was in each case terminated when three or more cracks or one or more chunk outs were observed in the substructure. The test was a five-pulley test (drive pulley diameter=60 mm, additional pulleys=50 mm) based on the VDA hot bending fatigue life test (as at 09.27.2005), which in turn uses nine pulleys. In a further departure from the VDA test, the test was carried out at a constant ambient temperature of 130 C.

[0043] Furthermore, the coefficient of friction (CoF) according to SAE J2432, 2015 edition, was determined under wet and dry conditions.

[0044] Finally, wear tests were carried out on a diesel engine (running time 72 hours). This comprised measuring the mass loss of the belts using a balance.

[0045] The oxidized polyethylene employed was the commercially available product POLYAVIN COP from Bezema and an aqueous suspension comprising 40 g/l of this product was formulated. The active substance in POLYAVIN COP is oxidized HDPE having a (weight-average) molecular weight of 5000 to 8000.

[0046] The following table summarizes the results obtained for examples A to D:

TABLE-US-00001 Example A (Comparative) B C (Comparative) D Belt height 4.1 mm 4.1 mm 4.7 mm 4.7 mm Belt length 6PK1378 6PK1378 6PK1329 6PK1329 Substructure EPDM 1 EPDM 1 EPDM 2 EPDM 2 Basis weight of pure textile 180 g/m.sup.2 180 g/m.sup.2 225 g/m.sup.2 225 g/m.sup.2 cover ply Material composition of textile Cotton 93%, Cotton 93%, Cotton 91%, Cotton 91%, cover ply Elastane 7% Elastane 7% Elastane 9% Elastane 9% Weight increase after immersion 6.5 g/m.sup.2 8 g/m.sup.2 in aqueous suspension comprising 40 g/l of oxidized HDPE and subsequent drying Adhesive layer between textile LDPE film, LDPE film, LDPE film, LDPE film, and substructure 30 m 30 m 30 m 30 m CoF dry 1.5 1.5 1.2 1.2 CoF wet 1.0 1.0 1.1 1.1 Average running time in bending 180 h 320 h 205 h 275 h fatigue life test at 130 C. Mass loss in wear test on a 1.10% 0.50% 2.50% 0.80% diesel engine after idling for 72 h
Comparable friction results were obtained under wet and dry conditions (CoF) for belt variants A and B and also C and D. However, belts B and D, whose textile coating was provided with oxidized HDPE prior to vulcanization, showed markedly higher bending fatigue lives than the comparative belts A and C, whose textile coatings contained no oxidized HDPE.

[0047] Significantly lower mass losses were also registered in the wear test.