Stabilizing additives for polyolefins

Claim 2

A stabilized composition comprising a highly crystalline polyolefin selected from the group consisting of polybutene-1, poly-4-methylpentene-1, polypropylene, polyethylene, and copolymers of propylene or ethylene with at least one other C 2 to C 8 terminal olefin, said polyolefin prepared by an essentially solvent-free, anionically catalyzed polymerization process wherein catalyst residues and low molecular weight and amorphous components are incompletely separated from the highly crystalline polyolefin; and a stabilizing amount of a partially esterified polyhydroxyl compound of the formula (HOCH 2 ) m C (CH 2 OZ) 4-m , wherein Z is H or COR, at least one Z is COR, m runs from 1 to 3, and R is an aliphatic group containing from about 8 to about 20 carbon atoms.

Claim 3

The composition of claim 1 wherein said compound is a monoester of pentaerythritol.

Claim 4

The composition of claim 2 wherein said compound is a monostearate, monolaurate, monopalmitate or monooleate ester of pentaerythritol.

Claim 5

The composition of claim 3 wherein said polyolefin is selected from the group consisting of polypropylene and copolymers of propylene and at least one other C 2 to C 8 terminal olefin.

Claim 6

The composition of claim 1 wherein said polyolefin is polypropylene and said compound is pentaerythritol monostearate.

Claim 7

A stabilized composition comprising: (a) a highly crystalline polyolefin selected from the group consisting of polybutene-1, poly-4-methylpentene-1, polypropylene, polyethylene, and copolymers of propylene or ethylene with at least one other C 2 to C 8 terminal olefin, said polyolefin prepared by an essentially solvent-free, anionically catalyzed polymerization process wherein catalyst residues and low molecular weight and amorphous components are incompletely separated from the highly crystalline polyolefin; (b) a stabilizing amount of a partially esterified polyhydroxyl compound of the formula (HOCH 2 ) m C (CH 2 OZ) 4-m wherein Z is H or COR, at least one Z is COR, m runs from 1 to 3, and R is an aliphatic group containing from about 8 to about 20 carbon atoms; and (c) at least one organophosphorus compound of the formula P(AR') 3 , wherein A is --O--, --S--, or --SCH 2 COO--, and R' is hydrogen or a hydrocarbyl radical selected from the group consisting of aryl, alkylaryl, and aliphatic groups having from about 8 to about 20 carbon atoms, at least one R' being a hydrocarbyl radical.

Claim 8

A stabilized composition comprising: (a) a highly crystalline polyolefin selected from the group consisting of polybutene-1, poly-4-methylpentene-1, polypropylene, polyethylene, and copolymers of propylene or ethylene with at least one other C 2 to C 8 terminal olefin, said polyolefin prepared by an essentially solvent-free, anionically catalyzed polymerization process wherein catalyst residues and low molecular weight and amorphous components are incompletely separated from the highly crystalline polyolefin; (b) a stabilizing amount of a partially esterified polyhydroxyl compound of the formula (HOCH 2 ) m C (CH 2 OZ) 4-m wherein Z is H or COR, at least one Z is COR, m runs from 1 to 3, and R is an aliphatic group containing from about 8 to about 20 carbon atoms; and (c) at least one organophosphorus compound of the formula P(AR') 3 , wherein A is --O--, --S--, or --SCH 2 COO--, and R' is hydrogen or a hydrocarbyl radical selected from the group consisting of aryl, alkylaryl, and aliphatic groups having from about 8 to about 20 carbon atoms, at least one R' being a hydrocarbyl radical.

Claim 9

The composition of claim 6 wherein the stabilizing amount of (b) ranges from about 0.01 to about 1 wt.% of the composition and the stabilizing amount of (c) ranges from about 0.01 to about 1 wt.% of the composition.

Claim 10

The composition of claim 7 wherein the (c) component is at least one trihydrocarbyl phosphite, trihydrocarbyl trithiophosphite, or trihydrocarbyltrithioglycolyl phosphite.

Claim 11

The composition of claim 8 wherein the (b) component is a monostearate, monolaurate, monopalmitate, or monooleate ester of pentaerythritol.

Claim 12

The composition of claim 9 wherein the highly crystalline polyolefin is polypropylene or a copolymer of propylene and another C 2 to C 8 terminal olefin.

Claim 13

The composition of claim 10 wherein the (b) component is pentaerythritol monostearate and the (c) component is selected from the group consisting of diphenyl isooctyl phosphite, trilauryl trithiophosphite, triisooctyltrithioglycolyl phosphite, tris(nonylphenyl) phosphite, and mixtures thereof.

Claim 14

The composition of claim 11 wherein the (c) component is diphenyl isooctyl phosphite.

Claim 15

The composition of claim 11 wherein the (c) component is trilauryl trithiophosphite.

Claim 16

The composition of claim 11 wherein the (c) component is triisooctyltrithioglycolyl phosphite.

Claim 17

The composition of claim 11 wherein the (c) component is tris(nonylphenyl) phosphite.

Claim 18

A process for preparing a stabilized composition comprising (a) contacting olefin monomer selected from the group consisting of butene-1, 4-methylpentene-1, propylene, ethylene, or a mixture of propylene or ethylene with at least one other C 2 to C 8 terminal olefin with an anionic catalyst system under essentially solvent-free polymerization conditions to form a product comprising highly crystalline polyolefin, low molecular weight and amorphous components, and anionic catalyst residues; and (b) incorporating into said product a stabilizing amount of a partially esterified polyhydroxyl compound of the formula (HOCH 2 ) m C(CH 2 OZ) 4-m wherein Z is H or COR, at least one Z is COR, m runs from 1 to 3, and R is an aliphatic group containing from about 8 to about 20 carbon atoms.

Claim 19

A process for preparing a stabilized composition comprising (a) contacting olefin monomer selected from the group consisting of butene-1, 4-methylpentene-1, propylene, ethylene, or a mixture of propylene or ethylene with at least one other C 2 to C 8 terminal olefin with an anionic catalyst system under essentially solvent-free polymerization conditions to form a product comprising highly crystalline polyolefin, low molecular weight and amorphous components, and anionic catalyst residues; and (b) incorporating into said product a stabilizing amount of a partially esterified polyhydroxyl compound of the formula (HOCH 2 ) m C(CH 2 OZ) 4-m wherein Z is H or COR, at least one Z is COR, m runs from 1 to 3, and R is an aliphatic group containing from about 8 to about 20 carbon atoms.

Claim 20

The process of claim 16 wherein said partially esterified polyhydroxyl compound is a monoester of pentaerythritol.

Claim 21

The process of claim 17 wherein the monoester of pentaerythritol is a monostearate, monolaurate, monopalmitate, or monooleate ester of pentaerythritol.

Claim 22

The process of claim 18 wherein the olefin monomer is propylene or a mixture of propylene with another C 2 to C 8 terminal olefin.

Claim 23

The process of claim 16 further comprising incorporating into said product a stabilizing amount of at least one organophosphorus compound of the formula P(AR') 3 wherein A is --O--, --S--, or --SCH 2 COO--, and R' is hydrogen or a hydrocarbyl radical selected from the group consisting of aryl, alkaryl, and aliphatic groups having from about 8 to about 20 carbon atoms, at least one R' being a hydrocarbyl radical.

Claim 24

The process of claim 20 wherein the organophosphorus compound is at least one trihydrocarbyl phosphite, trihydrocarbyl trithiophosphite, or trihydrocarbyl trithioglycolylphosphite.

Claim 25

The process of claim 21 wherein the partially esterified polyhydroxyl compound is a monoester of pentaerythritol.

Claim 26

The process of claim 22 wherein the monoester of pentaerythritol is a monostearate, monolaurate, monopalmitate, or monooleate ester of pentaerythritol.

Claim 27

The process of claim 23 wherein the olefin monomer is propylene or a mixture of propylene with another C 2 to C 8 terminal olefin.

Claim 28

The process of claim 16 wherein said essentially solvent-free polymerization conditions are bulk phase polymerization conditions.

Claim 29

The process of claim 16 wherein said essentially solvent-free polymerization conditions are vapor phase polymerization conditions.