Adhesive formulation and also method for the treatment of reinforcing inserts

Abstract

The present invention relates to an adhesive formulation in the form of an aqueous dispersion with a solids content of 10 to 40% by weight relative to the adhesive formulation, for the treatment of reinforcing inserts for the production of reinforced polymer products, 100% by weight of the solids containing a) 1 to 20% by weight of a bisphenol A epoxy novolak, b) 0 to 20% by weight of an entirely or partially blocked isocyanate, c) 60 to 92% by weight of a resorcinol formaldehyde latex (RFL).

Claims

1. An adhesive formulation in the form of an aqueous dispersion with a solids content of 10 to 40% by weight relative to the adhesive formulation, which is suitable for the treatment of reinforcing inserts for the production of reinforced polymer products, wherein 100% by weight of the solids containing a) 14.5 to 20% by the weight of a bisphenol A epoxy novolak, b) 14.5 to 20% by the weight of an entirely of partially blocked isocyanate, and c) 60 to 71% by weight of a resorcinol formaldehyde latex.

2. An adhesive formulation according to claim 1, wherein the solids content is 10 to 30% by weight.

3. An adhesive formulation according to claim 1, wherein the solids content is 15 to 30% by weight.

4. An adhesive formulation according to claim 1, wherein the solids content is 18 to 27% by weight.

5. An adhesive formulation according to claim 1, wherein the solids proportion a) of bisphenol A epoxy novolak is 15 to 19% by weight.

6. An adhesive formulation according to claim 3, wherein the solids proportion a) of bisphenol A epoxy novolak is 18 to 19% by weight.

7. An adhesive formulation according to claim 1, wherein the solids proportion b) of the blocked or partially blocked isocyanate is 15 to 19% by weight.

8. An adhesive formulation according to claim 1, wherein the isocyanate is blocked with lactam.

9. An adhesive formulation according to claim 1, wherein the isocyanate is 4,4-diisocyanate diphenylmethane and/or toluene diisocyanate and/or naphthyl diisocyanate.

10. An adhesive formulation according to claim 1, wherein the solids proportion c) of the RFL is 62-64% by weight.

11. An adhesive formulation according to claim 1, wherein the formulation contains 0.0001 to 0.1 mol/kg of a metal compound as catalyst selected from the group consisting of zinc, strontium, cadmium, sodium, caesium, potassium, silver, barium, titanium, chromium, tin, antimony, manganese, iron, cobalt, nickel, cerium, uranium, copper, calcium, zinc, lead and zirconium.

12. An adhesive formulation according to claim 1, further comprising one or more additive- and/or dispersion agents.

13. An adhesive formulation according to claim 1, which has a pot life of at least 6 hours.

14. An adhesive formulation according to claim 1, which has a pot life of at least 24 hours.

15. An adhesive formulation according to claim 1, which has a pot life of at least 48 hours.

16. An adhesive formulation according to claim 1, which has a pot life of at least 70 hours.

17. An adhesive formulation according to claim 1, which has a pot life of at least 100 hours.

18. A method for treating a reinforcing insert suitable for the production of a reinforced polymer product, comprising applying to said reinforcing insert an adhesive formulation according to claim 1.

19. A method according to claim 18, wherein the adhesive formulation is produced directly before the treatment by mixing the individual components.

20. A method according to claim 18, wherein the adhesive formulation is produced immediately before application by mixing component c) into the formulation already present as a mixture of components a) and b).

21. A method according to claim 18, wherein a non-activated reinforcing insert is treated.

22. A method according to claim 18, wherein the reinforcing insert is a tyre cord, conveyor cord or V-belt cord.

23. A method according to claim 18, wherein a non-activated reinforcing insert made of polyester is treated.

Description

(1) 1) Comparative Example

(2) A dispersion with the following composition of the solids proportion was produced:

(3) 14.5% by weight ECN-1400

(4) 14.5% by weight Grilbond IL-6

(5) 71% by weight RFL

(6) For this purpose, 121 parts deionised water were placed in a vessel and in succession 805 parts RFL and 37 parts ECN-1400 and 37 parts IL -6 were added with agitation and subsequently agitated for a further 15 minutes at 25° C.

(7) 2) Example According To The Invention

(8) A dispersion with the following composition of the solids proportion was produced:

(9) 14.5% by weight bisphenol A epoxy novolak

(10) 14.5% by weight Grilbond 1L-6

(11) 71% by weight RFL.

(12) For this purpose, 121 parts deionised water were placed in a vessel and in succession 805 parts RFL and 37 parts bisphenol A epoxy novolak and 37 parts IL -6 were added with agitation and subsequently agitated for a further 15 minutes at 25° C.

(13) The non-activated cord Performance Fibers HMLS polyester, 1,100×1×2 dtex, ZS 470, 1×50 were coated with the formulations 1) and 2) in a one-step process on a laboratory dip unit. The adhesion results are reproduced in Data Set 1 (comparative example) and 2 (example according to the invention).

(14) As the test results show, the one-step dip, according to the comparative example, i.e. with a cresol epoxy novolak, now has significantly poorer pot lives, which is shown in a severe drop in adhesion after 5 hours dip duration (Data Set 1). In addition, a base coating in the coating bath is shown already after 5 hours.

(15) The relative peel value indicated in Data Set 1 was thereby measured according to ASTM D 4393 with Continental B458 as test rubber.

(16) However it was shown that a one-step dip according to the invention with a bisphenol A epoxy novolak itself has, after a pot life of 70 hours and even after 100 hours, excellent adhesion. Reference is made in this respect to Data Set 2 which shows again the relative peel values, as also in Data Set 1, measured according to ASTM D 4393 with Continental 13458 as test rubber. Neither after 70 hours nor after 101 hours can any base coating in the coating bath be established:

(17) TABLE-US-00001 Data Set 1 Usage duration of the adhesive Relative peel value formulation [%] 1 96 2 94 3 96 4 96 5 100 6 85 8 70

(18) TABLE-US-00002 Data Set 2 Usage duration of the adhesive Relative peel value formulation [%] 1 96 6 94 24 91 48 9396 72 100 80 100 101 99