Vulcanization-accelerating mixture
The present invention relates to a mixture which can be used as vulcanization accelerator, to a process for producing the mixture and to use of the mixture, to vulcanizates which comprise the said mixtures or which comprise corresponding individual constituents of the mixture, and also to vulcanizates which are produced with use of the said mixture.
1. A mixture for accelerating vulcanization of halogen-containing rubbers, the mixture comprising:
(1) 10-70 wt % 3-methylthiazolidine-2-thione,
(2) 10-60 wt % tetrabenzylthiuram disulphide, and
(3) 1-60 wt % at least one Lewis acid selected from the group consisting of stannous chloride, stannous chloride dihydrate, tin dioctanoate, tin oxalate, dibutyltin carboxylate, monobutyltin tris(2-ethylhexanoate), dibutyltin oxide, aluminium(III) chloride, titanium tetrachloride, antimony pentachloride, zinc chloride, and zinc chloride dihydrate,
wherein the sum of the weight percents of constituents (1), (2) and (3) in the mixture is 100%.
2. The mixture according to claim 1 , wherein the at least one Lewis acid is bound on a polymer selected from the group consisting of acrylate rubber (ACM), ethylene-acrylate rubber (AEM), polyurethane rubber (PU), butyl rubber (IIR), butadiene rubber (BR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), epichlorohydrin polymer (CO), chlorobutadiene rubber (CR), chlorosulphonated polyethylene polymer (CSM), ethylene oxide-epichlorohydrin rubber (ECO), ethylene-propylene diene rubber (EPDM), ethylene-methyl acrylate copolymer (EMA), perfluoro rubber (FFPM), fluoro rubber (FPM), fluoromethylpolysiloxane (FVMQ), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR), natural rubber (NR), styrene-butadiene rubber (SBR), chlorinated polyethylene (PE-C) and/or ethylene-vinyl acetate polymer (EVA/EVM) and/or any desired mixtures of these polymers.
3. The mixture according to claim 1 , wherein the at least one Lewis acid is stannous chloride dihydrate.
4. A process for producing the mixture according to claim 1 , the process comprising mixing the 3-methylthiazolidine-2-thione, the tetrabenzylthiuram disulphide, and the at least one Lewis acid with one another.
5. A process for producing a rubber vulcanizate, the process comprising: mixing rubber to be vulcanized with the mixture according to claim 1 as a vulcanization accelerator, and vulcanizing the rubber mixture.
6. The process according to claim 5 , further comprising using the mixture according to claim 1 as a vulcanization accelerator wherein the rubber is chloroprene rubber (CR), butyl rubber (IIR), bromobutyl rubber (BIIR), chlorobutyl rubber (CIIR), epichlorohydrin polymer (CO), chlorosulphonated polyethylene polymer (CSM), epichlorohydrin rubber (CO), ethylene oxide-epichlorohydrin rubber (ECO), chlorinated polyethylene polymer (CM) and other rubbers or a mixture thereof.
7. The mixture according to claim 2 , wherein the at least one Lewis acid is stannous chloride dihydrate.
8. The mixture according to claim 1 , wherein the at least one Lewis acid is stannous chloride dihydrate bound to butyl rubber.
9. The mixture according to claim 1 , wherein the mixture comprises:
(1) 30-50 wt % of the 3-methylthiazolidine-2-thione,
(2) 25-50 wt % of the tetrabenzylthiuram disulphide, and
(3) 15-30 wt % of the at least one Lewis acid.
10. A mixture for accelerating vulcanization of halogen-containing rubbers, the mixture comprising:
3-methylthiazolidine-2-thione,
tetrabenzylthiuram disulphide, and
stannous chloride dihydrate bound to butyl rubber wherein the sum of the weight percents of constituents of 3-methylthiazolidine-2-thione, tetrabenzylthiuram disulphide, and stannous chloride dihydrate bound to butyl rubber in the mixture is 100.