Process for bonding a textile material to an elastomer

Abstract

The present invention relates to a process for adhering a textile material to an elastomer, the process comprising the steps of pretreating the textile material with at least one polyester of an α-β-unsaturated carboxylic acid, contacting the pretreated textile material with an unvulcanized elastomer, and vulcanizing the product obtained. The present invention additionally encompasses an elastomer article obtainable by this process and also the use of a polyester of an α-β-unsaturated carboxylic acid for improving the adhesion of a textile material to an elastomer.

Claims

1. A process for adhering a textile material to an elastomer, the process comprising the steps of: a) pretreating the textile material with at least one polyester of an α-β-unsaturated carboxylic acid; b) contacting the pretreated textile material with an unvulcanized elastomer; and c) vulcanizing the product obtained from the step of contacting the pretreated textile material with an unvulcanized elastomer; wherein the textile material is not treated with resorcinol-formaldehyde latex in the process for adhering a textile material to an elastomer.

2. The process as claimed in claim 1, wherein the textile material is selected from the group consisting of fibers, threads, sheet textiles and combinations thereof.

3. The process as claimed in claim 2, wherein the sheet textiles are selected from the group consisting of woven fabrics, knitted fabrics, nonwovens and combinations thereof.

4. The process as claimed in claim 1, wherein the textile material comprises a material selected from the group consisting of polyester, polyamide, aramid, polyurethane, glass, carbon, viscose and combinations thereof.

5. The process as claimed in claim 1, wherein the textile material is selected from the group consisting of woven polyester fabric, woven polyamide fabric, polyester thread, aramid thread, aramid fibers, glass fibers, carbon fibers, viscose fibers and combinations thereof.

6. The process as claimed in claim 1, wherein the at least one polyester of an α-β-unsaturated carboxylic acid is selected from the group consisting of trimethylolpropane trimethacrylate, trimethylolpropane triacrylate and combinations thereof.

7. The process as claimed in claim 1, wherein the unvulcanized elastomer is a rubber component selected from the group consisting of an ethylene-propylene copolymer (EPM), an ethylene-propylene-diene copolymer (EPDM), a hydrogenated nitrile rubber (HNBR), a chloroprene rubber (CR), a fluoro rubber (FKM), a natural rubber (NR), a styrene-butadiene rubber (SBR), a butadiene rubber (BR) and combinations thereof.

8. The process as claimed in claim 1, wherein the textile material that has been pretreated with the at least one polyester of an α-β-unsaturated carboxylic acid is broken down into smaller parts or fragments prior to being contacted with the unvulcanized elastomer and is subsequently contacted with the unvulcanized elastomer by being mixed into the unvulcanized elastomer.

9. The process as claimed in claim 8, wherein the textile material is short aramid fiber, the at least one polyester of an α-β-unsaturated carboxylic acid is trimethylolpropane trimethacrylate and the elastomer is ethylene-propylene-diene copolymer (EPDM) or a hydrogenated nitrile rubber (HNBR).

10. The process as claimed in claim 1, wherein an elastomer article is obtainable by the process.

11. The process as claimed in claim 10, wherein the elastomer article is a tape, strap, belt, hose, air spring bellows, expansion joint or a multilayer fabric web.

12. The process as claimed in claim 10, wherein the elastomer article is a drive belt, wherein the elastomer forms a main body comprising a top ply as belt backing and a substructure having a power transmission zone, wherein the top ply and/or the power transmission zone has/have been provided with the textile material.

13. The process as claimed in claim 12, wherein the drive belt is designed as a flat belt, V-belt, a V-ribbed belt, a toothed belt, a clutch belt or an elevator belt.

14. The process as claimed in claim 12, wherein the textile material is short aramid fiber, wherein the at least one polyester of an α-β-unsaturated carboxylic acid is trimethylolpropane trimethacrylate, and wherein the unvulcanized elastomer is ethylene-propylene-diene copolymer (EPDM).

15. The process as claimed in claim 12, wherein the textile material is short aramid fiber, wherein the at least one polyester of an α-β-unsaturated carboxylic acid is trimethylolpropane trimethacrylate, and wherein the unvulcanized elastomer is hydrogenated nitrile rubber (HNBR).

16. The process as claimed in claim 12, wherein the textile material is short aramid fiber, the α-β-unsaturated carboxylic acid is trimethylolpropane trimethacrylate and the unvulcanized elastomer is peroxidically crosslinked HNBR.

17. The process as claimed in claim 12, wherein the textile material is short aramid fiber having a length in the range of from 4 cm to 8 cm.

18. The process as claimed in claim 12, wherein the textile material that has been pretreated with the at least one polyester of an α-β-unsaturated carboxylic acid is broken down into smaller parts or fragments prior to being contacted with the unvulcanized elastomer and is subsequently contacted with the unvulcanized elastomer by being mixed into the unvulcanized elastomer.

Description

EXAMPLES

Example 1

(1) Woven polyester fabric is immersed into pure trimethylolpropane trimethacrylate (CAS 3290-92-4), roughly cleaned of excess coating material and laid onto an unvulcanized rubber sheet formed from a mixture based on a peroxide-crosslinked HNBR rubber mixture. The structure is vulcanized under pressure for 20 minutes at 180° C. The following separation forces (determined according to DIN 53530) result for the product obtained by the process according to the invention and also for the corresponding comparison products with RFL treatment or without treatment of the woven polyester fabric:

(2) TABLE-US-00001 Raw woven polyester fabric 1.2 N/mm separation force without treatment (comparison) RFL-dipped woven polyester fabric 3.7 N/mm separation force (comparison) Woven polyester fabric according 2.4 N/mm separation force to the invention with treatment

(3) The example above proves that the process according to the invention also achieves a marked improvement in the adhesion between the elastomer and textile material compared to the untreated textile material, although the improvement in the adhesion does not quite approach that of the conventional RFL system.

Example 2

(4) A raw-edged V-belt is manufactured with a woven fabric coated raw woven polyamide fabric that has been immersed in trimethylolpropane triacrylate (CAS 15625-89-5). The belt exhibits a cohesive strength (determined according to DIN 53530) of the woven fabric of 2.5 N/mm compared to 1.9 N/mm for an uncoated woven fabric.

Example 3

(5) A polyester thread is drawn through a bath containing trimethylolpropane triacrylate (CAS 15625-89-5). A V-ribbed belt is manufactured from this thread.

(6) The article displays a pull-out force (determined according to ISO 12046) of 20 N. In contrast, when using a non-coated thread to produce the V-ribbed belt, it exhibits a pull-out force (determined according to ISO 12046) of 14 N.

Example 4

(7) An aramid thread is immersed in trimethylolpropane trimethacrylate (CAS 3290-92-4) and cut into short fiber pieces (short aramid fibers). These fiber pieces are mixed into a peroxidically crosslinked HNBR mixture. After vulcanization, the following values result in the longitudinal direction for the short fibers treated by means of the process according to the invention and, for comparison, for the untreated short fibers and for fibers treated with ester plasticizer (ester of trimellitic acid). In addition, for comparison trimethylolpropane trimethacrylate was also added directly to the mixture, that is to say the fibers were also not treated beforehand with the α-β-unsaturated carboxylic acid here:

(8) TABLE-US-00002 Short fibers according to the invention Modulus 10*: 8.1 MPa Untreated short fibers Modulus 10*: 3.5 MPa Fibers treated with ester plasticizer Modulus 10*: 1.8 MPa Untreated short fibers, where 3% Modulus 10*: 3.6 MPa CAS3290-92-4 was added to the mixture Short fibers treated with RFL Modulus 10*: 8.2 MPa *Modulus 10 = stress value at 10% elongation