Method of making a functionalized elastomer, elastomer, rubber composition and tire
The present invention is directed to a method of making a functionalized elastomer, comprising the step of polymerizing a conjugated diene monomer in the presence of a lanthanide-based coordination polymerization catalyst activated with a functionalized aluminum reagent of formula 1 where R is a linear or branched alkane group containing 1 to 8 carbon atoms, and R1 is phenylene, or a linear or branched alkane diyl group containing 2 to 10 carbon atoms, or a combination of one or more phenylene groups and one or more linear or branched alkane diyl groups containing 1 to 10 carbon atoms; Q is of formula 2 where R3 and R4 are independently phenyl or a linear or branched alkyl group containing 1 to 10 carbon atoms, or R3 and R4 taken together with the nitrogen atom represent a nitrogen containing heterocyclic group containing from 4 to 12 carbon atom.
1. A method of making a functionalized elastomer, comprising the step of polymerizing a conjugated diene monomer in the presence of a lanthanide-based coordination polymerization catalyst activated with a functionalized aluminum reagent of formula 1
wherein R is a linear or branched alkane group containing 1 to 8 carbon atoms, and R1 is phenylene, or a linear or branched alkane diyl group containing 2 to 10 carbon atoms, or a combination of one or more phenylene groups and one or more linear or branched alkane diyl groups containing 1 to 10 carbon atoms; Q is of formula 2
wherein R3 and R4 are independently phenyl or a linear or branched alkyl group containing 1 to 10 carbon atoms, or R3 and R4 taken together with the nitrogen atom represent a nitrogen containing heterocyclic group containing from 4 to 12 carbon atoms.
2. The method of claim 1 , wherein functionalized aluminum reagent is selected from the group consisting of
where TMS is a trimethylsilyl group.
3. The method of claim 1 , wherein the conjugated diene monomer is selected from the group consisting of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, and 2-phenyl-1,3-butadiene.
4. The method of claim 1 , further comprising the step of terminating polymerization using a functional terminator.
5. The method of claim 4 , wherein the functional terminator is an organic compound substituted with a functional group comprising at least one heteroatom selected from phosphorus, boron, oxygen, halogens and silicon.
6. The method of claim 4 , wherein the functional terminator is selected from the group consisting of tetraethoxysilane, n-octyltriethoxysilane, 3-chloropropyltriethoxysilane, and chlorodiphenylphosphine.
7. The method of claim 1 , wherein the conjugated diene monomer is functionalized.
8. The method of claim 1 , wherein the lanthanide-based coordination polymerization catalyst comprises a neodymium carboxylate and an organoboron salt compound.
9. The method of claim 8 , wherein the neodymium carboxylate comprises an organic monocarboxylic acid ligand that contains from 1 to 20 carbon atoms.
10. The method of claim 9 , wherein the organic monocarboxylic acid ligand is selected from the group consisting of acetic acid, propionic acid, valeric acid, hexanoic acid, 2-ethylhexanoic acid, neodecanoic acid, lauric acid, and stearic acid.
11. The method of claim 8 , wherein the neodymium carboxylate is selected from the group consisting of neodymium naphthenate, neodymium neodecanoate, and neodymium octanoate.
12. The method of claim 8 , wherein the organoboron salt compound is an ionic compound consisting of an organoboron anion with a cation, wherein the organoboron anion is selected from the group consisting of tetraphenylborate ([BPh4]-), tetrakis(monofluorophenyl)borate ([B(C 6 F 5 ) 4 ] − ), tetrakis(difluorophenyl)borate, tetrakis(trifluorophenyl)borate, tetrakis(tetrafluorophenyl)borate, tetrakis(pentafluorophenyl)borate, tetrakis(tetrafluoromethylphenyl)borate, tetra(tolyl)borate, tetra(xylyl)borate, (triphenyl, pentafluorophenyl)borate, [tris(pentafluorophenyl), phenyl]borate, and decahydro-7,8-dicarbanium borate, and the cation in selected from the group consisting of a carbonium cation, an oxonium cation, an ammonium cation, a phosphonium cation, a cycloheptatrienyl cation, and a ferrocenium cation containing a transition metal.
13. The method of claim 8 , wherein the organoboron salt compound is selected from the group consisting of [Ph 3 C][B(C 6 F 5 ) 4 ], [PhNMe 2 H][BPh 4 ], [NEt 3 H][BPh 4 ], and [PhNMe 2 H][B(C 6 F 5 ) 4 ].