Ziegler-natta catalyst for high temperature polymerization

• US 7,666,810 B2
• Filed: 07/26/2007
• Issued: 02/23/2010
• Est. Priority Date: 08/25/2006
• Status: Active Grant

• Current Assignee: Nova Chemicals
• Original Assignee: Nova Chemicals
• Inventors: Wang, Qinyan
• Primary Examiner(s): CHOI, LING SIU
• Application Number:
  US11/881,241
• Publication Number:
  US 20080051534A1
• Time in Patent Office: 943 Days
• Field of Search: 526/124.2, 526/144, 526/348, 502/103, 502/115, 502/113, 502/119, 502/104
• US Class Current: 502/115
• CPC Class Codes: C08F 10/00 Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• CPC Class Codes: C08F 2/06 Organic solvent
• CPC Class Codes: C08F 210/14 Monomers containing five or more carbon atoms
• CPC Class Codes: C08F 210/16 Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
• CPC Class Codes: C08F 2500/03 Narrow molecular weight distribution, i.e. Mw/Mn < 3
• CPC Class Codes: C08F 2500/10 Short chain branches
• CPC Class Codes: C08F 4/6543 halides of magnesium
• CPC Class Codes: C08F 4/6546 organo-magnesium compounds
• CPC Class Codes: C08F 4/6555 and magnesium or compounds thereof

Abstract

A magnesium titanium olefin polymerization procatalyst is prepared by A) reacting a diorganomagnesium compound with a source of active chlorine, (with the proviso that the amount of chlorine is insufficient to completely convert the diorganomagnesium to magnesium dichloride); then B) removing unreacted diorganomagnesium from the reaction product; then depositing a tetravalent titanium species on the reaction product. This procatalyst is highly active for the solution polymerization of olefins when combined with a cocatalyst.

Claims

1. A process to prepare an olefin polymerization procatalyst, said process comprising:

Step a);

forming a solid product by reacting;

i) a diorganomagnesium compound defined by the formula MgRaRb, wherein each of Ra and Rb is independently selected from the group consisting of C₁ to C₈ hydrocarbyl groups, with

ii) a source of active chlorine, wherein the mole ratio of chlorine in said active chlorine to said Mg is less than 2 and the mole ratio of chlorine in said active chlorine to the total moles of (Ra+Rb) is from 1.55 to 1.90/1;

Step b);

collecting said solid product from step a) and separating said solid product from said diorganomagnesium which did not react in said step a);

washing said solid product;

adding to said solid product a tetravalent titanium chloride species of the formula;

TiCl_n(OR)_m, wherein n is from 2 to 4 and n+m=4 and wherein OR is a ligand selected from the group consisting of alkoxy, aryloxy and mixtures thereof.

2. The process of claim 1 wherein the Mg/Ti mole ratio is from 5/1 to 10/1.

3. The process of claim 1 when conducted at a temperature of from 20°

C. to 80°

C.

4. The process of claim 1 wherein said tetravalent titanium chloride species is TiCl₄.

5. The process of claim 1 wherein said active chloride is selected from the group consisting of HCl, isopropyl chloride and tertiary butyl chloride.

6. A process to prepare an olefin polymerization catalyst comprising:

I) Step a);

forming a solid product by reacting;

i) a diorganomagnesium compound defined by the formula MgRaRb, wherein each of Ra and Rb is independently selected from the group consisting of C₁ to C₈ hydrocarbyl groups, with

ii) a source of active chlorine, wherein the mole ratio of chlorine in said active chlorine to said Mg is less than 2 and the mole ratio of chlorine in said active chlorine to the total moles of (Ra+Rb) is from 1.55 to 1.90/1;

Step b);

collecting said solid product from step a) and separating said solid product from said diorganomagnesium which did not react in said step a);

washing said solid product;

adding to said solid product a tetravalent titanium chloride species of the formula;

TiCl_n(OR)_m, wherein n is from 2 to 4 and n+m=4 and wherein OR is a ligand selected from the group consisting of alkoxy, aryloxy and mixtures thereof;

II) adding an activator.

7. The process of claim 6 wherein said activator is an aluminum hydrocarbyl of the formula AlR¹_x(OR¹)_y wherein:

x is from 1 to 3 and x+y=3

R¹ is C₁ to C₁₀ hydrocarbyl

OR¹ is an alkoxy or aryloxy.

8. The process of claim 6 wherein the Al/Ti mole ratio is from 0.5/1 to 50/1.

9. A polymerization process for the polymerization of olefins comprising contacting an olefin polymerization catalyst prepared by the process of claim 6 with at least one alpha olefin under polymerization conditions.

10. The process of claim 9 wherein said polymerization conditions are solution polymerization conditions for the copolymerization of ethylene with at least one alpha olefin selected from the group consisting of C₃ to C₈ alpha olefins.

11. The process of claim 10 wherein said activator is an aluminum hydrocarbyl of the formula AlR¹_x(OR¹)_y wherein:

x is from 1 to 3 and x+y=3

R¹ is C₁ to C₁₀ hydrocarbyl

OR¹ is an alkoxy or aryloxy.

12. The process of claim 11 wherein the Al/Ti mole ratio is from 0.5/1 to 5/1.

13. The process of claim 9 wherein said tetravalent titanium chloride species is titanium tetrachloride.