CORROSION RESISTANCE OF RUBBER-BASED ADHESIVES AND SEALANTS

Abstract

The present invention relates to a hot-curing reactive composition based on natural and/or synthetic elastomers containing olefinic double bonds, and further containing at least one vulcanization system, as well as the use thereof as a one-component adhesive, sealant, as sealing compound or coating compound in vehicle construction, in particular in automotive body assembly. The present invention further relates to the use of corrosion protection pigments for improving the corrosion protection effect of such compositions.

Claims

1. A hot-curing, reactive composition based on natural and/or synthetic elastomers containing olefinic double bonds, wherein the hot-curing, reactive composition further comprises at least one vulcanization system and at least one corrosion protection pigment.

2. The hot-curing reactive composition according to claim 1, wherein the at least one corrosion protection pigment comprises at least one metal phosphate salt.

3. The hot-curing reactive composition according to claim 2, wherein the at least one corrosion protection pigment is present in an amount of from approximately 3.0 wt. % to approximately 8.0 wt. %, in each case based on total weight of the composition.

4. The hot-curing reactive composition according to claim 2, wherein the at least one metal phosphate salt is a metal orthophosphate salt, a metal triphosphate salt, a metal polyphosphate salt or mixtures thereof; and/or the at least one metal phosphate salt comprises at least one metal cation selected from alkali metal cations, alkaline earth metal cations, transition metal cations and cations of the boron group.

5. The hot-curing reactive composition according to claim 4, wherein the at least one metal cation is a cation of a metal selected from the group consisting of Zn, Al, Ca, Sr, Mo, Ba and Pb.

6. The hot-curing, reactive composition according to claim 1, wherein the at least one corrosion protection pigment is selected from the group consisting of an aluminum polyphosphate compound, zinc aluminum orthophosphate, zinc orthophosphate hydrate, zinc molybdenum orthophosphate hydrate, a calcium phosphate complex, zinc aluminum polyphosphate hydrate, strontium aluminum polyphosphate hydrate, aluminum triphosphate and combinations thereof.

7. The hot-curing reactive composition according to claim 6, wherein the at least one corrosion protection pigment is present in an amount of from approximately 0.1 wt. % to approximately 10 wt. %, in each case based on total weight of the composition.

8. The hot-curing, reactive composition according to claim 1, wherein the natural and/or synthetic elastomers containing olefinic double bonds comprise at least one liquid polyene selected from the group consisting of polybutadienes, polybutenes, polyisobutylenes, 1,4- and 3,4-polyisoprenes, styrene-butadiene copolymers, butadiene-acrylonitrile copolymers and combinations thereof.

9. The hot-curing, reactive composition according to claim 8, wherein the natural and/or synthetic elastomers containing olefinic double bonds comprise at least one solid rubber from the group cis-1,4-polybutadiene, styrene-butadiene rubber, synthetic isoprene rubber, natural rubber, ethylene propylene diene rubber (EPDM), polycyclooctenamer, nitrile rubber, butyl rubber, acrylic rubber or polychloroprene.

10. The hot-curing reactive composition according to claim 9, wherein the at least one corrosion protection pigment is contained in an amount of from approximately 0.1 to approximately 10 wt. %, based on total weight of the composition.

11. The hot-curing reactive composition according to claim 1, wherein the at least one vulcanization system is selected from the group consisting of b1) sulfur and one or more accelerators; b2) one or more peroxides or disulfide vulcanization systems; and b3) quinones, quinone dioximes, nitrosobenzene and/or dinitrosobenzene.

12. The hot-curing reactive composition according to claim 1, wherein the at least one vulcanization system is a peroxide-based vulcanization system and the composition contains at least one organic peroxide compound present in an amount of approximately 0.1 wt. % to approximately 5 wt. %, in each case based on total weight of the composition.

13. The hot-curing, reactive composition according to claim 1, wherein the hot-curing, reactive composition further comprises at least one crosslinking agent containing multiple (meth)acryloyl groups.

14. The hot-curing reactive composition according to claim 13, wherein the at least one crosslinking agent containing multiple (meth)acryloyl groups is present in an amount of approximately 0.1 wt. % to approximately 5 wt. %, in each case based on total weight of the composition.

15. The hot-curing, reactive composition according to claim 1, wherein the hot-curing, reactive composition additionally contains fillers, rheological aids, extender oils, blowing agents, further pigments different from the corrosion protection pigment, adhesion promoters and/or aging inhibitors.

16. A hot-curing, reactive composition comprising components in weight %: a. A solid rubber present in an amount of about 0.1-9%; b. A maleic anhydride-grafted polybutadiene, present in an amount of about 1-20%; c. A liquid polybutadiene, having a cis 1,4-proportion of more than 80%, present in an amount of about 2-50%; d. A vulcanization agent present in an amount of about 0.1-7%; e. A vulcanization accelerator present in an amount of about 0.25-8%; f. A crosslinker containing multiple (meth)acryloyl groups present in an amount of about 0.1-5% g. A corrosion protection pigment present in an amount of about 0.1-10% h. Filler present in an amount of about 10-65%; and optionally 0-10% of a second liquid polybutadiene, having a 1,2 vinyl proportion of more than 50% up to about 80%; 0-40% Softening agent; 0-40% Hydrocarbon resin; 0-2% Bifunctional vulcanization crosslinker; 0-6% Chemical blowing agent/activator; 0-6% Physical blowing agent; 0-10% Zinc oxide; and 0-1.5% Antioxidant.

17. A one-component adhesive, sealant or coating composition comprising the hot-curing, reactive composition according to claim 1.

18. A method of assembling an automotive body comprising steps of: applying the one-component adhesive, sealant or coating composition comprising the hot-curing, reactive composition according to claim 17 to automotive body components, optionally joining the components; and hot-curing the adhesive, sealant or coating composition thereby forming a cured adhesive, sealant or coating.

19. A method of improving metal corrosion protection effect of a hot-curing, reactive composition which comprises natural and/or synthetic elastomers containing olefinic double bonds and a vulcanization system, the method comprising a step of adding at least one corrosion protection pigment comprising at least one metal phosphate salt prior to application and hot-curing of the composition, wherein the at least one metal phosphate salt is present in an amount of from approximately 0.1 wt. % to approximately 10 wt. %, in each case based on total weight of the composition.

Description

EXAMPLES

[0065] All quantity specifications listed in the Tables are in wt. %

TABLE-US-00002 TABLE 2 b2)-based cure Component Example 1 Example 2 Example 3 Example 4 Solid polybutadiene; 5.90 4.50 5.90 4.00 cis-1,4 proportion > 95% Maleic anhydride- 4.80 6.00 6.00 4.00 grafted polybutadiene Liquid polybutadiene, 16.25 20.50 18.00 12.25 cis-1,4 proportion > 80% Talc 17.58 Calcium carbonate 16.42 38.37 34.50 42.15 Coated calcium 17.20 17.60 17.20 17.20 carbonate Calcium dioxide 4.80 4.78 4.80 4.80 Mineral oil 6.25 10.25 Antioxidant 0.30 0.40 0.30 0.05 Amorphous 0.30 0.20 0.30 0.30 carbon black Expanding hollow 0.10 0.15 0.60 microspheres Benzenesulfinic 0.10 acid zinc salt Azodicarbonamide 1.00 Aluminum triphosphate 5.00 5.00 4.00 2.00 Aromatic hydrocarbon 2.00 5.00 resin in oil Silica, hydrophobic 0.50 Liquid polybutadiene, 1.00 1,2 vinyl Peroxide 1.40 1.00 1.40 1.40 Acrylate monomer 1.70 1.00 0.50 1.00 co-agent

TABLE-US-00003 TABLE 3 b1)-based cure Component Example 5 Example 6 Example 7 Example 8 Solid polybutadiene; 5.00 7.8 6.1 6.00 cis-1,4 proportion > 95% Maleic anhydride- 4.00 4.3 6.1 6.0 grafted polybutadiene Liquid polybutadiene, 18.14 24.48 6.1 22.4 cis-1,4 proportion > 80% Talc Calcium carbonate 44.27 32.81 26.8 25.95 Coated calcium 12.04 18.7 20.4 13.2 carbonate Calcium dioxide 2.9 2.5 2.55 8.00 Mineral oil 5.00 20.47 Antioxidant 0.30 0.3 0.50 0.50 Amorphous 0.37 0.3 2.0 0.50 carbon black Expanding hollow 0.22 0.62 1.02 0.2 microspheres Benzenesulfinic 0.1 0.17 acid zinc salt Azodicarbonamide 0.8 1.53 Aluminum triphosphate 1.16 1.19 3.24 6.40 Aromatic hydrocarbon resin in oil Silica, hydrophobic Liquid polybutadiene; 2.2 1,2 vinyl proportion > Sulfur 3.50 2.5 1.02 3.75 Organic accelerator 3.00 1.1 1.2 5.00 Acrylate monomer 0.1 0.3 0.8 2.1 co-agent

TABLE-US-00004 TABLE 4 b3)-based cure Component Example 9 Example 10 Solid polybutadiene; 5.00 6.35 cis-1,4 proportion > 95% Maleic anhydride- 1.73 1.2 grafted polybutadiene Liquid polybutadiene, 5.0 24.1 cis-1,4 proportion > 80% Talc Calcium carbonate 49.2 40.53 Coated calcium 12.0 11.9 carbonate Calcium dioxide 2.5 2.0 Mineral oil 20.00 Antioxidant 0.5 0.1 Amorphous 2.00 0.3 carbon black Expanding hollow 0.23 microspheres Benzenesulfinic 0.1 acid zinc salt Azodicarbonamide 0.3 Di-nitrosopentamethylenetetramine 0.2 Aluminum triphosphate 0.65 3 Aromatic hydrocarbon resin in oil Silica, hydrophobic 9.23 Liquid polybutadiene; 1,2 vinyl proportion > 50% Benzoquinone dioxime 0.39 0.99 Acrylate monomer 0.4 0.1 co-agent