LOW SPEED CROSS-LINKING CATALYST FOR SILANE-GRAFTED PLASTOMERS

Abstract

The present invention relates to silane crosslinking catalyst comprising: —75 to 85 wt.-% of an olefin acrylate interpolymer and—15 to 25 wt.-% of a hindered amine light stabilizer (HALS) having a number average molecular weight Mn of 1500 to 4000 g/mol; and—optionally up to 5 wt.-% wax, wherein the silane crosslinking catalyst is free of tin, carboxylic acid(s) and sulphonic acid(s), all weight percentages with respect to the total weight of the silane crosslinking catalyst.

Claims

1-14. (canceled)

15. A silane crosslinking catalyst comprising 75 to 85 wt.-% of an olefin acrylate interpolymer and 15 to 25 wt.-% of a hindered amine light stabilizer (HALS) having a number average molecular weight Mn of 1500 to 4000 g/mol; and optionally up to 5 wt.-% wax, wherein the silane crosslinking catalyst is free of tin, carboxylic acid(s), and sulphonic acid(s), and wherein all weight percentages are with respect to the total weight of the silane crosslinking catalyst.

16. The silane crosslinking catalyst according to claim 15, wherein the olefin acrylate interpolymer is selected from the group consisting of ethylene butyl acrylate (EBA), ethylene ethyl acrylate (EEA), and ethyl methyl acrylate (EMA); and/or the olefin acrylate interpolymer has a MFR (2.16 kg load, ISO1133) of 5 to 15 g/10 min; and/or the hindered amine light stabilizer (HALS) has a melting temperature of at least 95° C.; and/or the wax is present in an amount of 2.0 wt.-% or less with respect to the total weight of the silane crosslinking catalyst.

17. The silane crosslinking catalyst according to claim 15, wherein the silane crosslinking catalyst does not contain a butylated reaction product of p-cresol and dicyclopentadiene.

18. The silane crosslinking catalyst according to claim 15, wherein the silane crosslinking catalyst does not contain an alkoxysilane.

19. The silane crosslinking catalyst according to claim 15, wherein the olefin acrylate interpolymer is ethylene butyl acrylate (EBA) having a content of butyloxy group O—CH.sub.2—CH.sub.2—CH.sub.2—CH.sub.3 of 15 to 20 wt.-% with respect to the total ethylene butyl acrylate (EBA), and/or a melt flow rate of 5.0 to 10.0 g/10 min (ISO1133, 2.16 kg load, 190° C.).

20. A crosslinkable formulation comprising (1) a grafted ethylene alpha olefin plastomer containing silane crosslinker in an amount of 0.1 to 10 wt.-% with respect to the grafted ethylene alpha olefin plastomer, wherein the grafted ethylene alpha olefin plastomer is obtained by grafting an ethylene octene plastomer and/or grafting a plastomer having a density of from 850 kg/m.sup.3 to 870 kg/m.sup.3 and/or grafting a plastomer having an melt flow rate (ISO 1133, 2.16 kg, 190° C.) of 0.40 to 1.5 g/10 min; and (2) a silane crosslinking catalyst according to claim 15.

21. A process of crosslinking an ethylene alpha olefin plastomer, the process comprising: (a) providing an ethylene alpha olefin plastomer having one or more of the following characteristics: the ethylene alpha olefin plastomer is an ethylene octene plastomer; having a density of from 850 kg/m.sup.3 to 870 kg/m.sup.3; and having a melt flow rate (ISO 1133, 2.16 kg, 190° C.) of 0.40 to 1.5 g/10 min; (b) grafting the ethylene alpha olefin plastomer to provide a grafted ethylene alpha olefin plastomer such that the content of silane crosslinker is in an amount of 0.1 to 10 wt.-% with respect to the grafted ethylene alpha olefin plastomer; (c) contacting said grafted ethylene alpha olefin plastomer with a silane crosslinking catalyst according to claim 15 at a temperature sufficient for at least partial crosslinking, thereby providing an at least partially crosslinked ethylene alpha olefin plastomer.

22. A process for providing a fluids transport product comprising the steps of: (a) providing a grafted ethylene alpha olefin plastomer having a content of silane crosslinker of 0.1 to 10 wt.-% with respect to the grafted ethylene alpha olefin plastomer; (b) extruding said grafted ethylene alpha olefin plastomer into a tubular structure in the presence of a silane crosslinking catalyst according to claim 15; (c) optionally reinforcing the tubular structure by fabric and further optionally covering the fabric with the same or a different grafted ethylene alpha olefin plastomer also having a content of silane crosslinker of 0.1 to 10 wt.-%; (d) optionally labelling the outer surface; (e) optionally fixing the labelling if present by utilizing UV rays; (f) washing the structure obtained; (g) cutting the structure into semi-finished products (h) maintaining the semi-finished products at a temperature of from 10 to 25° C. and relative humidity of up to 60%; (i) placing the semi-finished products on shaped mandrels; (j) subjecting the semi-finished products placed on the shaped mandrels to curing by increasing temperature and optionally increasing pressure, and further optionally increasing relative humidity thereby obtaining cured semi-finished fluids transport products having a predetermined shape; and (k) optionally washing and further optionally trimming the cured semi-finished fluids transport products to yield the fluids transport products.

23. The process according to claim 22, wherein maintaining the semi-finished products at a temperature of from 10 to 25° C. and relative humidity of from up to 60% in step (h) lasts at least 24 hours.

24. The process according to claim 22, wherein the fluids transport product is a hose.

25. A fluid transport product or hose obtained by the process of claim 23.

26. A vehicle comprising a fluid transport product or hose according to claim 25.

Description

EXAMPLE 1

[0187] The silane crosslinking catalysts RC1, RC2 and IC2 were tested on plastomers subjected to grafting. The used reactants are indicated in Table 1.

TABLE-US-00001 TABLE 1 Crosslinking degree of the inventive silane crosslinking catalyst IC1 (24 h, 48 h, 4 days) Plastomer Gel content after MFR Density VTMS crosslinking at RT Name (g/10 min) (kg/m.sup.3) % IC1 24 h 48 h 4 days P1 0.5 863 2.0 5% 8%  8% 22% P2 1 857 1.8 5% 5% 13%  7% P3 0.5 861 1.7 5% 11%  20% 32%

[0188] It can be seen the crosslinking degree remained on a surprisingly low level even for up to 4 days.

TABLE-US-00002 TABLE 2 Crosslinking degree of the reference silane crosslinking catalyst RC2 (24 h, 48 h, 4 days) Plastomer Gel content after MFR Density VTMS crosslinking at RT Name (g/10 min) (kg/m.sup.3) % RC2 24 h 48 h 4 days P1 0.5 863 2.0 5% 96% 96% 96% P2 1 857 1.8 5% 96% 96% 96% P3 0.5 861 1.7 5% 96% 96% 96%

TABLE-US-00003 TABLE 3 Crosslinking degree of the reference silane crosslinking catalyst RC1 (24 h, 48 h, 4 days) Plastomer Gel content after MFR Density VTMS crosslinking at RT Name (g/10 min) (kg/m.sup.3) % RC1 24 h 48 h 4 days P1 0.5 863 2.0 5% 96% 96% 96% P2 1 857 1.8 5% 96% 96% 96% P3 0.5 861 1.7 5% 96% 96% 96%

[0189] It can be seen the crosslinking degree could not be maintained at a low level e.g. for storage.

[0190] All tests were made on 2 mm extruded tapes using 95% plastomer (Engage and Queo) and 5% of a catalyst.

EXAMPLE 2

[0191] All tapes using IC1 (Table 1) after experimental treatment for 4 days were (as described above) were placed in a water bath using deionized water at 90° C. for 24 hours.

TABLE-US-00004 TABLE 4 Crosslinking degree of the inventive silane crosslinking catalyst IC1 after cross-linking in water bath. Plastomer Gel content after MFR (g/10 Density VTMS crosslinking at Name min) (kg/m.sup.3) % IC1 90° C. for 24 h P1 0.5 863 2.0 5% >70% P2 1 857 1.8 5% >70% P3 0.5 861 1.7 5% >70%

[0192] IE1 showed crosslinking of above 70% gel content, i.e. Cooper Standard specification (minimum 70% gel content) after 24 h was met.

[0193] The inventive silane crosslinking catalysts allows modifying reaction rates according to the industrial needs.

EXAMPLE 3

[0194] The production operation included an extrusion of a rubber like tube which is reinforced in another step by a fabric material.

[0195] Cooling and forming was effected under water thereby forming a hose. The hoses were cut to the required length providing semi-finished products. The semi-finished products were maintained at 23° C. and 55% relative humidity for 4 days.

[0196] After that the semi-finished products were placed on the shaped mandrels and subjected to curing (autoclave, 20 minute curing program consisting of 10 minutes at 140° C. at 3.6 bar and 10 min at 7.6 bar).

[0197] Then cured hoses were removed from the mandrels. Shape retention was observed.

[0198] Gel content was measured and was well above 70%.

[0199] It could be shown the silane crosslinking catalysts allows an extremely advantageous process for providing a fluids transport products.