Process for producing stereoregular polymers having a narrow molecular weight distribution

• US 5,093,415 A
• Filed: 05/19/1987
• Issued: 03/03/1992
• Est. Priority Date: 05/19/1987
• Status: Expired due to Term

• Current Assignee: Union Carbide Corporation (Dow, Inc.)
• Original Assignee: Union Carbide Chemicals & Plastics Technology Corporation (Dow, Inc.)
• Inventors: Stakem, Francis G., Liu, Han T., Noshay, Allen, Brady, Robert C. III
• Primary Examiner(s): Smith, Edward J.
• Application Number:
  US07/051,853
• Time in Patent Office: 1,750 Days
• Field of Search: 526/124, 526/128, 525/53
• US Class Current: 525/53
• 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 4/6465 containing silicium
• CPC Class Codes: Y10S 526/901 Monomer polymerized in vapor state in presence of transition metal containing catalyst

Abstract

Stereoregular polymers having a molecular weight distribution of less than 5.0 and an isotactic index in excess of 96 percent are produced by polymerizing an alpha-olefin having 3 to 8 carbon atoms in a low pressure gas phase fluid bed process at a temperature in excess of 80° C. employing a heat stable catalyst system comprising (a) a solid catalyst component containing magnesium, titanium, halide and a polycarboxylic acid ester containing two coplanar ester groups attached to adjacent carbon atoms, as inside electron donor, (b) an organoaluminum cocatalyst, and (c) a silicon compound containing a silicon-oxygen-carbon linkage, as outside electron donor.

Claims

1. A process for producing propylene polymers having a molecular weight distribution of from 3.0 to 4.5 and an isotatic index of from 97 percent to 99 percent which comprises contacting propylene in a fluid bed reactor, at a pressure no greater than 7000 kPa and a temperature of at least 100°

C., with a catalytically effective amount of a catalyst system comprising

(a) a solid catalyst component containing magnesium, titanium, halide and a polycarboxylic acid ester containing two coplanar ester groups attached to adjacent carbon atoms, said catalyst component being obtained by halogenating a magnesium compound of the formula MgR'"'"'R", wherein R'"'"' and R" are alkoxide groups containing from 1 to 8 carbon atoms, with titanium tetrachloride, in the presence of (1) an aromatic halohydrocarbon containing from 6 to 12 carbon atoms and from 1 to 2 halogen atoms and (2) a polycarboxylic acid ester derived from (i) a branched or unbranched monohydric alcohol containing from 1 to 12 carbon atoms and (ii) a monocyclic or polycyclic aromatic compound containing from 8 to 20 carbon atoms and two carboxyl groups which are attached to ortho carbon atoms of the ring structure,

(b) an organoaluminum cocatalyst, and

(c) an electron donor containing a silicon-oxygen-carbon linkage and having the formula

space="preserve" listing-type="equation">R""'"'"'.sub.m SiY.sub.n X.sub.p

wherein

R""'"'"' is a hydrocarbon radical containing from 1 to 20 carbon atoms,

Y is --OR""" or --COR""" wherein R""" is a hydrocarbon radical containing from 1 to 20 carbon atoms,

X is hydrogen or halogen,

m is an integer having a value of from 0 to 3,

n is an integer having a value of from 1 to 4,

p is an integer having a value of from 0 to 1, and

m+n+p is equal to 4,

said catalyst containing an atomic ratio of aluminum in the organoaluminum cocatalyst to silicon in the electron donor of from 0.5;

1 to 100;

1, and an atomic ratio of aluminum in the organoaluminum cocatalyst to titanium in the solid catalyst component of from 5;

1 to 300;

1.

2. A process as in claim 1 wherein the magnesium compound is magnesium diethoxide.

3. A process as in claim 2 wherein the halohydrocarbon is chlorobenzene.

4. A process as in claim 3 wherein the polycarboxylic acid ester is diisobutyl phthalate.

5. A process as in claim 4 wherein the halogenated product is treated twice with additional titanium tetrachloride and the second treatment is effected in the presence of a polycarboxylic acid halide containing two coplanar acid halide groups attached to adjacent carbon atoms.

6. A process as in claim 5 wherein the polycarboxylic acid halide is phthaloyl dichloride,

7. A process as in claim 4 wherein propylene is copolymerized with up to 20 mole percent ethylene in a second polymerization reactor in the presence of the product of the first polymerization reactor.

8. A process as in claim 4 wherein the electron donor containing a silicon-oxygen-carbon linkage is diphenyldimethoxysilane.

9. A process as in claim 6 wherein the electron donor containing a silicon-oxygen-carbon linkage is diphenyldimethoxysilane.