Low molecular weight nitrile rubber
View Patent ↗The present invention relates to nitrile rubber polymers having lower molecular weights and narrower molecular weight distributions than those known in the art. The present invention also relates to a process for the manufacture of said nitrile rubber and the use of said nitrile rubber for the manufacture of shaped articles.
1. A process for the preparation of a nitrile rubber comprising the step of subjecting said nitrile rubber to a metathesis reaction in the presence of at least one co-olefin and at least one compound selected from the group consisting of compounds having the formula I, II, III or IV
wherein
M is Os or Ru,
R and R 1 are, independently, hydrogen or a hydrocarbon selected from the group consisting of C 2 -C 20 alkenyl, C 2 -C 20 alkynyl, C 1 -C 20 alkyl, aryl, C 1 -C 20 carboxylate, C 1 -C 20 alkoxy, C 2 -C 20 alkenyloxy, C 2 -C 20 alkynyloxy, aryloxy, C 2 -C 20 alkoxycarbonyl, C 1 -C 20 alkylthio, C 1 -C 20 alkylsulfonyl and C 1 -C 20 alkylsulfinyl,
X and X 1 are independently any anionic ligand, and
L and L 1 are independently any neutral ligand; optionally, L and L 1 can be linked to one another to from a bidentate neutral ligand;
wherein
M 1 is Os or Ru;
R 2 and R 3 are, independently, hydrogen or a hydrocarbon selected from the group consisting of C 2 -C 20 alkenyl, C 2 -C 20 alkynyl, C 1 -C 20 alkyl, aryl, C 1 -C 20 carboxylate, C 1 -C 20 alkoxy, C 2 -C 20 alkenyloxy, C 2 -C 20 alkynyloxy, aryloxy, C 2 -C 20 alkoxycarbonyl, C 1 -C 20 alkylthio, C 1 -C 20 alkylsulfonyl and C 1 -C 20 alkylsulfinyl,
X 2 is a anionic ligand,
L 2 is a neutral □-bonded ligand independent of whether they are mono- or polycyclic,
L 3 is a ligand selected from the group consisting of phosphines, sulfonated phosphines, fluorinated phosphines, functionalized phosphines bearing up to three aminoalkyl-, ammoniumalkyl-, alkoxyalkyl-, alkoxylcarbonylalkyl-, hydrocycarbonylalkyl-, hydroxyalkyl- or ketoalkyl-groups, phosphites, phosphinites, phosphonites, phosphinamines, arsines, stibenes, ethers, amines, amides, imines, sulfoxides, thioethers and pyridines,
Y − is a non-coordinating anion,
n is an integer in the range of from 0 to 5;
wherein
M 2 is Mo or W,
R 4 , R 5 are, independently, hydrogen or a hydrocarbon selected from the group consisting of C 2 -C 20 alkenyl, C 2 -C 20 alkynyl, C 1 -C 20 alkyl, aryl, C 1 -C 20 carboxylate, C 1 -C 20 alkoxy, C 2 -C 20 alkenyloxy, C 2 -C 20 alkynyloxy, aryloxy, C 2 -C 20 alkoxycarbonyl, C 1 -C 20 alkylthio, C 1 -C 20 alkylsulfonyl and C 1 -C 20 alkylsulfinyl,
R 6 and R 7 are independently any unsubstituted or halo-substituted alkyl, aryl, aralkyl groups or silicon-containing analogs thereof,
wherein
M is Os or Ru,
R and R 1 are independently selected from the group consisting of hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted alkyl,
X and X 1 are independently any anionic ligand and
L and L 1 are independently any neutral ligand.
2. A process according to claim 1 wherein a compound of Formula I is present.
3. A process according to claim 2 wherein L and L 1 are trialkylphosphines, X and X 1 are chloride ions and M is ruthenium.
4. A process according to claim 1 wherein the co-olefin(s) is a C 2 to C 16 linear or branched olefin(s).
5. A process according to claim 4 wherein the co-olefin is selected from the group consisting of ethylene and 1-hexene.
6. A process according to claim 1 wherein the process is carried out in an inert solvent selected from the group consisting of monochlorobenzene, dichloromethane, benzene, toluene, tetrahydrofuran, methyl ethyl ketone and cyclohexane.
7. A process according to claim 1 wherein the nitrile rubber is present in a concentration in the range of from 1 to 40% by weight.