Method of functionalising an elastomeric material and the use thereof in rubber formulations
A method of functionalising an elastomeric material, such as a rubber particle, is provided. The method comprises the functionalisation of an elastomeric material through the use of an ionic liquid based composition, which comprises a water soluble polymer, a cationic silicate component, and a salt of a vulcanization accelerator, together with a zinc compound, sulphur, and an accelerator. Rubber particles, for example particles from recycled rubber products, functionalised according to the method disclosed can successfully be utilised in virgin rubber masterbatches at concentrations not previously possible.
1 . A method of functionalising a vulcanised elastomeric material, the method comprising the steps of:
a) providing a vulcanised elastomeric material having a surface to be functionalised,
b) providing an ionic liquid based composition comprising a water soluble polymer, a cationic silicate component, and a salt of a vulcanization accelerator,
c) providing a zinc compound, sulphur, and an accelerator,
d) contacting the ionic liquid based composition of step b) and the components of step c) with the vulcanised elastomeric material surface,
thereby to produce a functionalised elastomeric material.
2 . The method according to claim 1 , wherein the vulcanised elastomeric material is a vulcanised elastomeric particle.
3 . The method according to claim 2 , wherein the vulcanised elastomeric particle has a particle size range of about 10 to about 400 mesh.
4 . The method according to claim 1 , wherein the vulcanised elastomeric material is selected from the group consisting of ground rubber, scorched rubber, and micronized rubber powder.
5 . The method according to claim 1 , wherein the vulcanised elastomeric material is a recycled tyre rubber.
6 . The method according to claim 1 , wherein the ionic liquid based composition further comprises one or more of a reinforcing filler and a thermoplastic elastomer.
7 . The method according to claim 6 , wherein the reinforcing filler comprises precipitated silica.
8 . The method according to claim 7 , wherein the precipitated silica is silane-treated amorphous precipitated silica.
9 . The method according to claim 1 , wherein the method further comprises mixing the vulcanised elastomeric material of step a) with a reinforcing filler.
10 . The method according to claim 1 , wherein the vulcanization accelerator in the ionic liquid based composition of step b) is selected from a group of accelerator classes including thiazoles, dithiocarbamates, dithiophosphates, sulfenamides, thiuram sulfides, xanthates, guanidines, and aldehyde amines.
11 . The method according to claim 1 , wherein the salt of a vulcanization accelerator in the ionic liquid based composition of step b) is a salt of 2-mercaptobezothiazole (MBT), zinc dibenzyldithiocarbamate (ZBEC), zinc dialkyldithiophosphate (ZBOP), tetrabenzyl thiuramdisulfide (TBzTD), Di-isopropyl xanthogen disulphide (DIXD) or polysulfide (AS100), or combinations thereof, and wherein the salt of the vulcanization accelerator is a sodium or potassium salt thereof.
12 . The method according to claim 1 , wherein the cation of the cationic silicate component is a sodium or potassium cation.
13 . The method according to claim 1 , wherein the water soluble polymer is an ethylene oxide polymer or polyvinyl alcohol polymer.
14 . The method of claim 13 , wherein the water soluble polymer is polyethylene glycol.
15 . The method according to claim 1 , wherein the ionic liquid based composition comprises polyethylene glycol, sodium metasilicate and accelerator salt NaBEC.
16 . The method according to claim 1 , wherein the accelerator of step c) is selected from a group of accelerator classes including thiazoles, dithiocarbamates, dithiophosphates, sulfenamides, thiuram sulfides, xanthates, guanidines, and aldehyde amines.