Polymerization of ethylene in solution processes using a Ziegler-Natta catalyst and a hydrogenation catalyst
The catalyst system includes a heterogeneous procatalyst and a hydrogenation procatalyst. The heterogeneous procatalyst includes a titanium species, an aluminum species, and a magnesium chloride component. The hydrogenation procatalyst has the formula Cp 2 TiX 2 , In formula Cp 2 TiX 2 , each Cp is a cyclopentadienyl substituted with at least one R 1 , wherein R 1 is (C 1 -C 10 )alkyl; and each X is independently a halogen atom.
1. A catalyst system comprising:
a heterogeneous procatalyst comprising a titanium species, an aluminum species, and a magnesium chloride component, wherein the heterogeneous procatalyst comprises heterogeneous procatalyst particles having an average particle size from 0.1 micron to 10 microns; and
a hydrogenation procatalyst having the formula Cp 2 TiX 2 TiCp 2 or Cp 2 TiX n
where:
each Cp is cyclopentadienyl substituted with at least one (C 1 -C 10 )alkyl;
each X is independently monoanionic or neutral, wherein each X is independently (C 1 -C 40 ) hydrocarbon, (C 1 -C 40 ) heterohydrocarbon, (C 1 -C 40 ) hydrocarbyl, (C 1 -C 40 ) heterohydrocarbyl, or a halogen atom; and
n is 1 or 2.
2. The catalyst system of claim 1 , wherein the heterogeneous procatalyst is an unsupported bulk catalyst.
3. The catalyst system of claim 1 , wherein the heterogeneous procatalyst comprises heterogeneous procatalyst particles with a non-controlled morphology.
4. The catalyst system of claim 1 , wherein the heterogeneous procatalyst comprises heterogeneous procatalyst particles, wherein greater than or equal to 10% of the heterogeneous procatalyst particles have a particle size less than or equal to 1 micron.
5. The catalyst system of claim 1 , wherein the ratio of moles titanium in the hydrogenation procatalyst to moles titanium in the heterogeneous procatalyst is greater than 1:2.
6. The catalyst system of claim 1 , further comprising an alkyl aluminum cocatalyst Al(R 2 ) 3 , where each R 2 is independently (C 1 -C 20 )alkyl or halogen atom, provided at least one R 2 is (C 1 -C 20 )alkyl.
7. The catalyst system of claim 1 , further comprising an alkyl aluminum cocatalyst selected from the group consisting of trialkylaluminum compounds, dialkylaluminum chlorides, alkylaluminum dichlorides, alkylaluminum alkoxides, and alkylaluminoxanes.
8. The catalyst system claim 6 , wherein the ratio of moles titanium in the heterogeneous procatalyst to moles aluminum in the alkyl aluminum cocatalyst is greater than 2:1.
9. The catalyst system of claim 6 , wherein the ratio of moles titanium in the heterogeneous procatalyst to moles aluminum in the alkyl aluminum cocatalyst is from 1000:1 to 2:1.
10. A polymerization process comprising:
reacting (C 2 -C 12 ) α-olefins in solution in the presence of a catalyst system, the catalyst system comprising:
a heterogeneous procatalyst comprising a titanium species, an aluminum species, and a magnesium chloride component, wherein the heterogeneous procatalyst comprises heterogeneous procatalyst particles having an average particle size from 0.1 micron to 10 microns; and
a hydrogenation procatalyst having the formula Cp 2 TiX n TiCp 2 or Cp 2 TiX n
where:
each Cp is cyclopentadienyl substituted with at least one (C 1 -C 10 )alkyl;
each X is independently monoanionic or neutral, wherein each X is independently (C 1 -C 40 ) hydrocarbon, (C 1 -C 40 ) heterohydrocarbon, (C 1 -C 40 ) hydrocarbyl, (C 1 -C 40 ) heterohydrocarbyl, or a halogen atom; and n is 1 or 2.
11. The polymerization process of claim 10 , wherein the catalyst system further comprises a trialkylaluminum cocatalyst Al(R 2 ) 3 , where each R 2 is independently (C 1 -C 20 )alkyl.
12. The polymerization process of claim 10 , wherein the heterogeneous procatalyst is an unsupported bulk catalyst.
13. The polymerization process of claim 10 , wherein the heterogeneous procatalyst comprises heterogeneous procatalyst particles, wherein greater than or equal to 10% of the particles have a particle size less than or equal to 1 micron.
14. The polymerization process of claim 10 , wherein the heterogeneous procatalyst comprises heterogeneous procatalyst particles with a non-controlled particle morphology.
15. The polymerization process of claim 10 , wherein the (C 2 -C 12 ) α-olefins in solution are reacted in a reactor at a reaction temperature from 150° C. to 350° C.