Fibrous polyolefin particles and production thereof

Claim 2

A PARTICULATE POLYOLEFIN COMPRISING, PREDOMINANTLY, CONSTITUENT UNIT PARTICLES OF FIBROUS CHARACTER EACH BEING OF A LENGTH GREATER THAN 200 MICRONS AND A DIAMETER LESS THAN 1,000 MICRONS, THE RATIO OF THE LENGTH OF DIAMETER BEING GREATER THAN 5, MINOR PROPORTION OF THE UNIT PARTICLES RESPECTIVELY HAVING CORES OF FIBROUS CARRIER MATERIAL THEREIN, THE CONTENT OF WHICH WITHIN THE POLYOLEFIN ISLESS THAN 30 PERCENT BY WEIGHT.

Claim 3

A particulate polyolefin as claimed in claim 1 in which said polyolefin is selected from the group consisting of homopolymers of ethylene, propylene, butene-1, and pentene-1; copolymers of at least two monomers selected from the group consisting of ethylene, propylene, butene-1, and pentene-1; copolymers of predominant amount of at least one monomer selected from the group consisting of ethylene, propylene, butene-1, and pentene-1with at least one ethylenically unsaturated monomer other than said olefins.

Claim 4

A particulate polyolefin as claimed in claim 2 in which said polyolefin is selected from the group consisting of homopolymers of ethylene and of propylene, copolymers of ethylene and propylene.

Claim 5

A particulate polyolefins as claimed in claim 1 in which each of said unit particles is of a length of 500 Mu to 20,000 Mu , and a diameter of 20 Mu to 500 Mu , the ratio of the length to diameter being 10 to 1,000.

Claim 6

A particulate polyolefin as claimed in claim 1 in which said fibrous carrier material is of a length less than 50 mm and a diameter less than 0.1 mm.

Claim 7

A particulate polyolefin as claimed in claim 5 in which said fibrous carrier material is of a length of 0.1 to 10 mm and a diameter less than 0.05 mm.

Claim 8

A process for producing particulate polyolefins wherein an olefin is caused to undergo catalytic polymerization in a polymerization medium containing a catalyst dispersed therein, said catalyst comprising a combination of an organometal compound (B) of a metal in any of Groups I, II, and III of the periodic table and a lower-valent transition metal compound (A) obtained by reducing a transition metal compound (1) of maximum valence by means of an organo-metal compound (2) of a metal or any of Groups I, II, and III of the periodic table, said compound (1) being representable by the generAl formula MeXm (OR)n, where: Me is a transition metal of any of Groups IV, V, VI, and VIII of the periodic table; X is a halogen; m and n are zero or a positive integer, m + n being equal to the maximum valence of Me, and n being an integer from zero through 4; and R is a hydrocarbon of from 1 through 8 carbon atoms, said process being characterised in that said transition metal compound (A) is obtained by reducing said compound (1) in the presence of a fibrous carrier material with subsequent washing or heat treatment or a combination of these washing and heat-treatment steps, and said polymerization is continued thereby to produce a particulate polyolefin comprising predominantly constituent unit particles of fibrous character each being of a length greater than 200 microns and a diameter less than 1,000 microns, the ratio of the length to the diameter being greater than 5, a minor proportion of the unit particles having cores of fibrous carrier material therein, the content of which within the polyolefin is less than 30 percent by weight.

Claim 9

A process for producing particulate polyolefins wherein an olefin is caused to undergo catalytic polymerization in a polymerization medium containing a catalyst dispersed therein, said catalyst comprising a combination of an organometal compound (B) of a metal in any of Groups I, II, and III of the periodic table and a lower-valent transition metal compound (A) obtained by reducing a transition metal compound (1) of maximum valence by means of an organo-metal compound (2) of a metal or any of Groups I, II, and III of the periodic table, said compound (1) being representable by the generAl formula MeXm (OR)n, where: Me is a transition metal of any of Groups IV, V, VI, and VIII of the periodic table; X is a halogen; m and n are zero or a positive integer, m + n being equal to the maximum valence of Me, and n being an integer from zero through 4; and R is a hydrocarbon of from 1 through 8 carbon atoms, said process being characterised in that said transition metal compound (A) is obtained by reducing said compound (1) in the presence of a fibrous carrier material with subsequent washing or heat treatment or a combination of these washing and heat-treatment steps, and said polymerization is continued thereby to produce a particulate polyolefin comprising predominantly constituent unit particles of fibrous character each being of a length greater than 200 microns and a diameter less than 1,000 microns, the ratio of the length to the diameter being greater than 5, a minor proportion of the unit particles having cores of fibrous carrier material therein, the content of which within the polyolefin is less than 30 percent by weight.

Claim 10

A process for producing particulate polyolefins as claimed in claim 7 in which said olefin is at least one member selected from the group consisting ethylene, popylene, butene-1, and pentene-1.

Claim 11

A process for producing particulate polyolefins as claimed in claim 8 in which said olefin is selected from the group consisting of ethylene, propylene, and mixtures thereof.

Claim 12

A process for producing particulate polyolefins as claimed in claim 8 in which said olefin is in admixture with a minor amount of an ethylenically unsaturated monomer other than said olefin.

Claim 13

A process for producing particulate polyolefins as claimed in claim 7 in which said polymerization medium is liquid.

Claim 14

A process for producing particulate polyolefins as claimed in claim 7 said polymerization medium is gaseous.

Claim 15

A process for producing particulate polyolefins as claimed in claim 7 in which said metal Me is titanium, and X is chlorine.

Claim 16

A process for producing particulate polyolefins as claimed in claim 7 in which said compound (1) is a titanium tetrahalide.

Claim 17

A process for producing particulate polyolefins as claimed in claim 14 in which said titanium tetrahalide is titanium tetrachloride.

Claim 18

A process for producing particulate polyolefins as claimed in claim 7 in which said compound (B) is an organoaluminum compound representable by the general formula AlR''mX3 m where m is 1, 1.5, 2 or 3, R is a hydrocarbon group of 1 to 6 carbon atoms, and X is a halogen.

Claim 19

A process for producing particulate polyolefins as claimed in claim 16 in which said halogen is chlorine.

Claim 20

A process for producing particulate polyolefins as claimed in claim 7 in which said compound (2) is an organoaluminum compound representable by the general formula AlR''mX3 m where m is 1, 1.5, 2 to 3, R is a hydrocarbon atoms, and X is a halogen.

Claim 21

A process for producing particulate polyolefins as claimed in claim 7 in which said fibrous carrier material is of a length less than 50 mm and a diameter less than 0.1 mm.

Claim 22

A process for producing particulate polyolefins as claimed in claim 19 in which said fibrous carrier material is of a length of 0.1 to 10 mm and a diameter less than 0.05 mm.

Claim 23

A process for producing particulate polyolefins as claimed in claim 7 in which said compound (A) is obtained by reducing said compound (1) which has impregnated said fibrous carrier material.

Claim 24

A particulate polyolefin as in claim 1 in which said fibrous carrier material is asbestos.

Claim 25

A particulate polyolefin as in claim 1 in which said fibrous carrier material is selected from the group consisting of fibrous clay, asbestos and glass fibers.

Claim 26

A process for producing particulate polyolefin as claimed in claim 7 in which the fibrous carrier material is selected from the group consisting of fibrous clay, asbestos, and glass fibers.