JPH1045824A - Treatment of polyolefin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for treating a polyolefin by which the polyolefin hardly generating a smell in the time of molding is obtained by degrading and removing a remaining ligand having a cyclopentadienyl skeleton from the polyolefin produced by using a transition metal compound containing the ligand having the cyclopentadienyl skeleton. SOLUTION: This method for treating a polyolefin is performed by degrading a ligand in the polyolefin by bringing a polyolefin obtained by using a transition metal compound containing the ligand having the cyclopentadienyl skeleton into contact with a degrading agent of the ligand such as water, oxygen, an alcohol, an alkylene peroxide or a peroxide and thereafter heating the polyolefin brought into contact with the degrading agent of the ligand to remove the degraded ligand from the polyolefin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a polyolefin, and more particularly to a cyclopentadienyl residue remaining from a polyolefin obtained by using a transition metal compound containing a ligand having a cyclopentadienyl skeleton. The present invention relates to a method for removing a ligand having a skeleton.

[0002]

BACKGROUND OF THE INVENTION In recent years, a method for producing a polyolefin using a transition metal compound represented by a metallocene has attracted attention. When used as a catalyst component for olefin polymerization, the transition metal compound has characteristics such as high polymerization activity and narrow distribution of the obtained polymer.

[0003] The polyolefin obtained by using such a transition metal compound contains a transition metal compound used as a catalyst. Since the ligand of the transition metal compound is a cyclic compound residue having a conjugated double bond having a cyclopentadienyl skeleton, it may be a source of odor during heat processing, and is particularly delicate. In food applications where a strong smell or taste is important, the flavor and the like may be affected, so that the use may be limited to such applications.

As a method of treating a resin so as not to generate an odor during molding, for example, Japanese Patent Application Laid-Open No. 50-157486
Japanese Patent Application Laid-open No. Sho 57-157 proposes a method for removing a ligand by drying a resin pellet with an inert gas.
No. 18521 proposes a method of treating a resin pellet with a hot water column to remove a ligand.

However, in the above-mentioned conventional techniques, the ligand cannot be sufficiently removed, so that the generation of odor cannot be sufficiently suppressed, or the removal of the ligand requires much time or energy.

The present inventors have conducted intensive studies in view of the above prior art, and as a result, first contacted a polyolefin with a ligand decomposer such as water or alcohol to form a ligand remaining in the polyolefin. Was decomposed and then the polyolefin contacted with a ligand decomposer was heated, and it was found that the ligand, which is the source of the odor, could be efficiently removed, thereby completing the present invention.

[0007]

An object of the present invention is to decompose and remove a residual ligand having a cyclopentadienyl skeleton from a polyolefin produced using a transition metal compound containing a ligand having a cyclopentadienyl skeleton. It is another object of the present invention to provide a method for treating a polyolefin capable of obtaining a polyolefin with less odor during molding.

[0008]

SUMMARY OF THE INVENTION The process for treating a polyolefin according to the present invention comprises the steps of: (i) contacting a polyolefin obtained using a transition metal compound containing a ligand having a cyclopentadienyl skeleton with a ligand decomposer. And (ii) heating the polyolefin in contact with the ligand decomposer. More specifically, the method for treating a polyolefin according to the present invention comprises: (i) a polyolefin obtained by using a transition metal compound containing a ligand having a cyclopentadienyl skeleton; and a ligand decomposer. A ligand decomposition step of decomposing a ligand in the polyolefin by contacting the polyolefin; and (ii) heating the polyolefin in contact with the ligand decomposing agent to remove the decomposed ligand from the polyolefin. A child removing step.

The ligand decomposer includes at least one compound selected from the group consisting of water, oxygen, alcohol, alkylene oxide and peroxide.

The average particle size of the polymer in the ligand decomposition step is usually desirably in the range of 50 to 5000 μm. In the ligand decomposition step, for example, a gas stream containing the ligand decomposition agent is brought into contact with the polyolefin.

The heating temperature in the ligand removing step is as follows:
For example, when the crystallinity of the polyolefin is 40% or more, the temperature is not lower than the crystallization temperature of the polyolefin and lower than the decomposition temperature of the polyolefin, and when the crystallinity of the polyolefin is less than 40%, The melting point is −15 ° C. or higher and lower than the decomposition temperature of the polyolefin.

The heating temperature in the ligand removal step is, for example, such that the crystallinity of the polyolefin is 40%.
In the above case, the crystallization temperature of the polyolefin or more,
And when it is lower than the melting point of the polyolefin and the degree of crystallinity of the polyolefin is less than 40%, it is higher than or equal to the melting point of the polyolefin −15 ° C. and lower than the melting point of the polyolefin.

The ligand removing step is, for example, a step of heating the polyolefin in contact with the ligand decomposing agent at a temperature higher than the melting point of the polyolefin and lower than the decomposition temperature while applying a shearing force.

The ligand removing step includes, for example, (a) a step of heating and melting the polyolefin contacted with a ligand decomposing agent to produce a polyolefin pellet; Contacting with hot water,
(B-2) a step of bringing the pellets into contact with water vapor; and (b-3) a step of bringing the pellets to 0.001 to 0.098 MP.
This is a step including one step selected from the step of heating under the pressure of a.

The method for treating a polyolefin according to the present invention includes a step of decomposing a ligand having a cyclopentadienyl skeleton contained in the polyolefin and a step of removing the decomposed ligand. It is possible to obtain a polyolefin with less odor during molding.

[0016]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for treating a polyolefin according to the present invention will be specifically described. The method for treating a polyolefin according to the present invention comprises: (i) contacting a polyolefin obtained using a transition metal compound containing a ligand having a cyclopentadienyl skeleton with a ligand decomposing agent; ii) heating the polyolefin in contact with the ligand decomposer.

The polyolefin used in the present invention is obtained by using a transition metal compound containing a ligand having a cyclopentadienyl skeleton. As a transition metal compound containing a ligand having a cyclopentadienyl skeleton,
For example, a transition metal compound containing two ligands having a cyclopentadienyl skeleton represented by the following general formula (I), two cyclopentadienyl represented by the following general formula (II) A transition metal compound having a bidentate ligand in which a ligand having a skeleton is bonded via a divalent bonding group, and the like can be given.

[0018]

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(Wherein, M represents a transition metal atom of Group 4 of the periodic table of titanium, zirconium and hafnium, and Cp ¹ and Cp ² may be the same or different from each other and coordinate to the transition metal atom. A ligand having a cyclopentadienyl skeleton, wherein R ¹ and R ² may be the same or different and each have a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group, an aryloxy group, a trialkylsilyl group; Group,
Shows a halogen atom or a hydrogen atom. )

[0020]

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Wherein M, Cp ¹ , Cp ² , R ¹ and R ²
Is the same as in the general formula (I), and Y represents a divalent linking group such as alkylene and silylene. The polyolefin obtained using a transition metal compound containing a ligand having a cyclopentadienyl skeleton as described above contains a ligand having a cyclopentadienyl skeleton.

The ligand (group) having a cyclopentadienyl skeleton includes (substituted) cyclopentadienyl group,
(Substituted) indenyl group, (substituted) fluorenyl group and the like. Further, (substituted) cyclopentadienyl group,
And a group in which two ligands selected from a (substituted) indenyl group and a (substituted) fluorenyl group are bonded via a divalent bonding group.

The substituents of these ligands having a cyclopentadienyl skeleton include those having 1 to 2 carbon atoms.
0 (halogenated) hydrocarbon group, oxygen-containing group, silicon-containing group, halogen atom and the like.

Examples of the hydrocarbon group having 1 to 20 carbon atoms include an alkyl group, a cycloalkyl group, an alkenyl group, an arylalkyl group, an aryl group and the like. More specifically, methyl, ethyl, propyl, Alkyl groups such as butyl, hexyl, octyl, nonyl, dodecyl and eicosyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, norbornyl and adamantyl; vinyl,
Alkenyl groups such as propenyl and cyclohexenyl; arylalkyl groups such as benzyl, phenylethyl and phenylpropyl; phenyl, tolyl, dimethylphenyl, trimethylphenyl, ethylphenyl, propylphenyl, biphenyl, naphthyl, methylnaphthyl, anthryl and phenanthryl Aryl groups.

Examples of the halogenated hydrocarbon group having 1 to 20 carbon atoms include groups in which the aforementioned hydrocarbon group having 1 to 20 carbon atoms is substituted with halogen. A hydroxy group as the oxygen-containing group; methoxy, ethoxy, propoxy,
Alkoxy groups such as butoxy; aryloxy groups such as phenoxy, methylphenoxy, dimethylphenoxy and naphthoxy; and arylalkoxy groups such as phenylmethoxy and phenylethoxy.

Examples of the silicon-containing group include monohydrocarbon-substituted silyls such as methylsilyl and phenylsilyl; dihydrocarbon-substituted silyls such as dimethylsilyl and diphenylsilyl;
Trihydrosilyl substituted silyls such as trimethylsilyl, triethylsilyl, tripropylsilyl, tricyclohexylsilyl, triphenylsilyl, dimethylphenylsilyl, methyldiphenylsilyl, tritolylsilyl, and trinaphthylsilyl; silyls of hydrocarbon substituted silyls such as trimethylsilyl ether Ether; silicon-substituted alkyl groups such as trimethylsilylmethyl; and silicon-substituted aryl groups such as trimethylsilylphenyl.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. 2 selected from a (substituted) cyclopentadienyl group, a (substituted) indenyl group and a (substituted) fluorenyl group represented by Y
Examples of the divalent linking group that binds two ligands include a divalent hydrocarbon group having 1 to 20 carbon atoms, and a divalent hydrocarbon group having 1 to 20 carbon atoms.
0, a divalent halogenated hydrocarbon group, a divalent silicon-containing group, a divalent germanium-containing group, a divalent tin-containing group,
O -, - CO -, - S -, - SO -, - SO 2 -, - G
e-, -Sn-, -NR-, -P (R)-, -P (O)
(R)-, -B (R)-or -Al (R)-(wherein R may be the same as or different from each other, and may be a (halogenated) hydrocarbon group having 1 to 20 carbon atoms, hydrogen, Which is an atom or a halogen atom).

Specific examples of the divalent hydrocarbon group having 1 to 20 carbon atoms include methylene, dimethylmethylene, 1,2-
Ethylene, dimethyl-1,2-ethylene, 1,3-trimethylene, 1,4-tetramethylene, 1,2-cyclohexylene, 1,4-
Alkylene groups such as cyclohexylene; arylalkylene groups such as diphenylmethylene and diphenyl-1,2-ethylene;

Specific examples of the divalent halogenated hydrocarbon group having 1 to 20 carbon atoms include groups obtained by halogenating the above divalent hydrocarbon group having 1 to 20 carbon atoms such as chloromethylene. Is mentioned.

Examples of the divalent silicon-containing group include silylene,
Methylsilylene, dimethylsilylene, diethylsilylene, di (n-propyl) silylene, di (i-propyl) silylene, di (cyclohexyl) silylene, methylphenylsilylene, diphenylsilylene, di (p-tolyl) silylene, di (p- Alkylsilylene groups such as chlorophenyl) silylene; alkylarylsilylene groups; arylsilylene groups; alkyldisilylene groups such as tetramethyl-1,2-disilylene and tetraphenyl-1,2-disilylene; alkylaryldisilylene groups; And a silylene group.

Examples of the divalent germanium-containing group include groups in which silicon of the above-mentioned divalent silicon-containing group is substituted with germanium. Examples of the divalent tin-containing group include a group in which silicon of the divalent silicon-containing group is substituted with tin.

As the ligand having a cyclopentadienyl skeleton, specifically, a cyclopentadienyl group; methylcyclopentadienyl, dimethylcyclopentadienyl, ethylcyclopentadienyl, methylethylcyclopentadienyl , Propylcyclopentadienyl, methylpropylcyclopentadienyl, butylcyclopentadienyl, methylbutylcyclopentadienyl, trimethylcyclopentadienyl, tetramethylcyclopentadienyl, pentamethylcyclopentadienyl, hexylcyclopenta Substituted cyclopentadienyl groups such as dienyl and trimethylsilylcyclopentadienyl; indenyl groups; 2-methylindenyl, 2-ethylindenyl, 2-
Methyl-4-phenylindenyl, 2-ethyl-4-phenylindenyl, 2,4,7-trimethylindenyl, 3-methylindenyl, 2,7-dimethyl-4-propylindenyl, 2,7- Dimethyl-4-butylindenyl, 2,7-dimethyl-4-pentylindenyl, 2,7-dimethyl-4-hexylindenyl, 2,7
A substituted indenyl group such as -dimethyl-4-cyclohexylindenyl and 4,5,6,7-tetrahydroindenyl; a fluorenyl group; a substituted fluorenyl group.

In the above examples, the disubstituted cyclopentadienyl ring includes 1,2- and 1,3-substituted, and the tri-substituted includes 1,2,3- and 1,2 , 4-substituted. Alkyl groups such as propyl and butyl include n-,
Includes isomers such as i-, sec- and tert-.

A (substituted) cyclopentadienyl group,
As a group in which two ligands selected from a (substituted) indenyl group and a (substituted) fluorenyl group are bonded via a divalent bonding group, specifically, methylene-bis [1- (2-methyl) -4-phenylindenyl)], methylene-bis [1- (2-ethyl-4-phenylindenyl)], methylene-bis [1- (2-ethyl-4-naphthylindenyl)], ethylene-bis (Indenyl), ethylene-bis (4,5,6,7-tetrahydroindenyl), ethylene-bis [1- (2-methyl-4-phenylindenyl)], ethylene-bis [1- (2-ethyl -4-phenylindenyl)], ethylene-bis [1- (2-ethyl-4-naphthylindenyl)], ethylene-bis [1- (2-propyl-4-naphthylindenyl)], ethylene-bis [1- (2,4,7-trimethylindenyl)], isopropylidene- (cyclopentadienyl) (fluorenyl), isopropylidene- (cyclopentadienyl)
(Methylcyclopentadienyl), isopropylidene- (methylcyclopentadienyl) (3-methylindenyl), isopropylidene- (butylcyclopentadienyl) (3-methylindenyl), isopropylidene- (butylcyclo (Pentadienyl) (fluorenyl), isopropylidene-bis [1
-(2,4,7-trimethylindenyl)], dimethylsilylene-
Bis (cyclopentadienyl), dimethylsilylene-bis
(Methylcyclopentadienyl), dimethylsilylene-bis (dimethylcyclopentadienyl), dimethylsilylene
-Bis (trimethylcyclopentadienyl), dimethylsilylene-bis (indenyl), dimethylsilylene-bis (4,
5,6,7-tetrahydroindenyl), dimethylsilylene-bis (methylbutylcyclopentadienyl), dimethylsilylene- (cyclopentadienyl) (fluorenyl), dimethylsilylene- (butylcyclopentadienyl) (fluorenyl) , Dimethylsilylene- (butylcyclopentadienyl)
(Indenyl), diphenylsilylene-bis (indenyl), dimethylsilylene- (methylcyclopentadienyl)
(3-methylindenyl), dimethylsilylene- (butylcyclopentadienyl) (3-methylindenyl), dimethylsilylene-bis [1- (2-methyl-4-phenylindenyl)], dimethylsilylene-bis [1- (2-methyl-4-naphthylindenyl)], dimethylsilylene-bis [1- (2-methyl-4-anthrylindenyl)], dimethylsilylene-bis [1- (2-methyl-
4-phenanthrylindenyl)], dimethylsilylene-bis [1- (2-methyl-4- (fluorophenyl) indenyl)],
Dimethylsilylene-bis [1- (2-methyl-4- (pentafluorophenyl) indenyl)], dimethylsilylene-bis [1-
(2-methyl-4- (chlorophenyl) indenyl)], dimethylsilylene-bis [1- (2-methyl-4- (dichlorophenyl) indenyl)], dimethylsilylene-bis [1- (2-methyl-4- ( Bromophenyl) indenyl)], dimethylsilylene-bis [1
-(2-methyl-4- (tolyl) indenyl)], dimethylsilylene-bis [1- (2-methyl-4- (dimethylphenyl) indenyl)], dimethylsilylene-bis [1- (2-methyl-4 -(Ethylphenyl) indenyl)], dimethylsilylene-bis [1- (2-
Methyl-4- (propylphenyl) indenyl)], dimethylsilylene-bis [1- (2-methyl-4- (benzylphenyl) indenyl)], dimethylsilylene-bis [1- (2-methyl-4-biphenylyl) Indenyl)], dimethylsilylene-bis [1- (2-
Methyl-4- (trimethylsilylphenyl) indenyl)],
Dimethylsilylene-bis [1- (2-phenyl-4-phenylindenyl)], dimethylsilylene-bis [1- (2-ethyl-4-phenylindenyl)], dimethylsilylene-bis [1- (2- Ethyl-4-naphthylindenyl)], dimethylsilylene-bis [1
-(2-ethyl-4- (2-methyl-1-naphthyl) indenyl)], dimethylsilylene-bis [1- (2-ethyl-4-acenaphthylindenyl)], dimethylsilylene-bis [1- ( 2-ethyl-4-anthrylindenyl)], dimethylsilylene-bis [1- (2-ethyl-4-phenanthrylindenyl)], dimethylsilylene-bis [1- (2-ethyl-4- ( Methylphenyl) indenyl)], dimethylsilylene-bis [1- (2-ethyl-4- (dimethylphenyl) indenyl)], dimethylsilylene-bis [1-
(2-ethyl-4- (trimethylphenyl) indenyl)], dimethylsilylene-bis [1- (2-ethyl-4- (chlorophenyl) indenyl)], dimethylsilylene-bis [1- (2-ethyl-4-
(Dichlorophenyl) indenyl)], dimethylsilylene-
Bis [1- (2-ethyl-4- (bromophenyl) indenyl)],
Dimethylsilylene-bis [1- (2-ethyl-4-biphenylylindenyl)], dimethylsilylene-bis [1- (2-ethyl-4-
(Trimethylsilylphenyl) indenyl)], dimethylsilylene-bis [1- (2-propyl-4-phenylindenyl)],
Dimethylsilylene-bis [1- (2-propyl-4-naphthylindenyl)], dimethylsilylene-bis [1- (2-propyl-4-
(Methylnaphthyl) indenyl)], dimethylsilylene-bis [1- (2-propyl-4-acenaphthylindenyl)], dimethylsilylene-bis [1- (2-propyl-4-anthrylindenyl)], Dimethylsilylene-bis [1- (2-propyl-4-phenanthrylindenyl)], dimethylsilylene-bis [1- (2
-Butyl-4-phenylindenyl)], dimethylsilylene-
Bis [1- (2-butyl-4-naphthylindenyl)], dimethylsilylene-bis [1- (2-butyl-4- (methylnaphthyl) indenyl)], dimethylsilylene-bis [1- (2-butyl) -4-acenaphthylindenyl)], dimethylsilylene-bis [1- (2-butyl-4-anthrylindenyl)], dimethylsilylene-bis [1- (2-butyl-4-phenanthrylindenyl) )], Dimethylsilylene-bis [1- (2-pentyl-4-phenylindenyl)], dimethylsilylene-bis [1- (2-pentyl-4-naphthylindenyl)], dimethylsilylene-bis [1- (2-neopentyl-4-phenylindenyl)], dimethylsilylene-bis [1- (2-neopentyl-4-naphthylindenyl)], dimethylsilylene-bis [1- (2-hexyl-4-phenylindenyl) )], Dimethylsilylene-bis [1- (2-hexyl-4-naphthylindenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-4-ethylindenyl) )], Dimethylsilylene-bis [1
-(2,7-dimethyl-4-propylindenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-4-butylindenyl)],
Dimethylsilylene-bis [1- (2,7-dimethyl-4-pentylindenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-
4-hexylindenyl)], dimethylsilylene-bis [1-
(2,7-dimethyl-4-cyclohexylindenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-4- (methylcyclohexyl) indenyl)], dimethylsilylene-bis [1- (2,7 -
Dimethyl-4- (phenylethyl) indenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-4- (phenyldichloromethyl) indenyl)], dimethylsilylene-bis [1- (2,7-
Dimethyl-4- (chloromethyl) indenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-4- (trimethylsilylmethyl) indenyl)], dimethylsilylene-bis [1- (2,7-dimethyl- 4- (trimethylsiloxymethyl) indenyl)],
Dimethylsilylene-bis [1- (2-methyl-4-propyl-7-ethylindenyl)], dimethylsilylene-bis [1- (2,3,7-
Trimethyl-4-ethylindenyl)], dimethylsilylene-
Bis [1- (2,3,7-trimethyl-4-propylindenyl)],
Dimethylsilylene-bis [1- (2,3,7-trimethyl-4-butylindenyl)], dimethylsilylene-bis [1- (2,3,7-trimethyl-4-pentylindenyl)], dimethylsilylene -Bis [1- (2,3,7-trimethyl-4-hexylindenyl)], dimethylsilylene-bis [1- (2,3,7-trimethyl-4-cyclohexylindenyl)], dimethylsilylene-bis [1- (2,3,7
-Trimethyl-4- (methylcyclohexyl) indenyl)],
Dimethylsilylene-bis [1- (2,3,7-trimethyl-4- (trimethylsilyl) methylindenyl)], dimethylsilylene-
Bis [1- (2,3,7-trimethyl-4- (trimethylsiloxymethyl) indenyl)], dimethylsilylene-bis [1- (2,3,7-trimethyl-4- (phenylethyl) indenyl)], Dimethylsilylene-bis [1- (2,3,7-trimethyl-4- (phenyldichloromethyl) indenyl)], dimethylsilylene-bis [1-
(2,3,7-trimethyl-4- (chloromethyl) indenyl)], dimethylsilylene-bis [1- (2,7-dimethyl-4-propylindenyl)], dimethylsilylene-bis [1- (2 , 3,7-Trimethyl-4-propylindenyl)], dimethylsilylene-bis [1
-(2-methyl-4,6-di-propylindenyl)], dimethylsilylene-bis [1- (2-ethyl-4-propyl-7-methylindenyl)], dimethylsilylene-bis [1- ( 2-phenyl-4-propyl-7-methylindenyl)], dimethylsilylene-bis [1
-(2-methylindenyl)], diethylsilylene-bis [1-
(2,7-dimethyl-4-propylindenyl)], diethylsilylene-bis [1- (2-methyl-4-phenylindenyl)], diethylsilylene-bis [1- (2,3,7-trimethyl) -4-propylindenyl)], methylphenylsilylene-bis (indenyl), methylphenylsilylene-bis [1- (2-methyl-4-phenylindenyl)], methylphenylsilylene-bis [1-
(2-ethyl-4-phenylindenyl)], methylphenylsilylene-bis [1- (2-ethyl-4-naphthylindenyl)], methylphenylsilylene-bis [1- (2-ethyl-4-an Tolylindenyl)], methylphenylsilylene-bis [1- (2-ethyl-4-phenanthrylindenyl)], methylphenylsilylene-bis [1- (2,7-dimethyl-4-propylindenyl) ], Methylphenylsilylene-bis [1- (2,7-dimethyl-
4-butylindenyl)], methylphenylsilylene-bis
[1- (2,3,7-trimethyl-4-propylindenyl)], methylphenylsilylene-bis [1- (2,3,7-trimethyl-4-butylindenyl)], dipropylsilylene-bis [1- (2-methyl-4-phenylindenyl)], dipropylsilylene-bis
[1- (2,7-dimethyl-4-propylindenyl)], dipropylsilylene-bis [1- (2,3,7-trimethyl-4-propylindenyl)], dibutylsilylene-bis [1- (2-methyl-4-phenylindenyl)], dibutylsilylene-bis [1- (2,7-dimethyl-4-propylindenyl)], dibutylsilylene-bis [1- (2,3,7-trimethyl) -4-propylindenyl)], dicyclohexylsilylene-bis [1- (2-methyl-4-phenylindenyl)], dicyclohexylsilylene-bis [1- (2,7
-Dimethyl-4-propylindenyl)], dicyclohexylsilylene-bis [1- (2,3,7-trimethyl-4-propylindenyl)], diphenylsilylene-bis [1- (2-methyl-4-phenyl) Indenyl)], diphenylsilylene-bis [1- (2-ethyl-4-phenylindenyl)], diphenylsilylene-bis [1- (2-ethyl-4-naphthylindenyl)], diphenylsilylene-bis [ 1- (2-ethyl-4-anthrylindenyl)], diphenylsilylene-bis [1- (2-ethyl-4-phenanthrylindenyl)], diphenylsilylene-bis [1- (2
-Ethyl-4-biphenylylindenyl)], diphenylsilylene-bis [1- (2,7-dimethyl-4-butylindenyl)], diphenylsilylene-bis [1- (2,7-dimethyl-4-) Propylindenyl)], diphenylsilylene-bis [1- (2,7-dimethyl-4-ethylindenyl)], diphenylsilylene-bis [1
-(2,3,7-trimethyl-4-butylindenyl)], diphenylsilylene-bis [1- (2,3,7-trimethyl-4-propylindenyl)], diphenylsilylene-bis [1- ( 2,3,7-trimethyl-4-ethylindenyl)], ditolylsilylene-bis [1
-(2-methyl-4-phenylindenyl)], ditolylsilylene-bis [1- (2,7-dimethyl-4-propylindenyl)], ditolylsilylene-bis [1- (2,3, 7-trimethyl-4-propylindenyl)], di (chlorophenyl) silylene-bis [1- (2
-Methyl-4-phenylindenyl)], di (chlorophenyl)
Silylene-bis [1- (2,7-dimethyl-4-propylindenyl)], di (chlorophenyl) silylene-bis [1- (2,3,7-trimethyl-4-propylindenyl)], dimethyl gel Millen-bis [1- (2-methyl-4-phenylindenyl)], dimethylgermylene-bis [1- (2-ethyl-4-phenylindenyl)], dimethylgermylene-bis [1- (2 -Ethyl-4-naphthylindenyl)], dimethylgermylene-bis [1- (2-propyl-4-phenylindenyl)], dimethylstannylene-bis [1- (2-methyl-4-phenylindenyl) )]Such.

In the above examples, disubstituted cyclopentadienyl rings include 1,2- and 1,3-substituted ones, and tri-substituted ones include 1,2,3- and 1,2 , 4-substituted. Alkyl groups such as propyl and butyl include n-,
Includes isomers such as i-, sec- and tert-.

The polyolefin used in the present invention is obtained by using a transition metal compound containing a ligand having a cyclopentadienyl skeleton as described above, and containing a ligand having a cyclopentadienyl skeleton. I have. In the present invention,
Contacting the polyolefin with a ligand decomposer to decompose a ligand in the polyolefin (ligand decomposition step); and heating the polyolefin contacted with the ligand decomposer to decompose. A step of removing the ligand thus obtained from the polyolefin (ligand removal step) is performed. Examples of the ligand decomposer used in the ligand decomposition step include water, oxygen, alcohol, alkylene oxide, peroxide, and the like.Specifically, methanol, ethanol, propanol, isopropanol, butanol, pentanol, Alcohols having 10 or less carbon atoms, such as monoalcohols such as hexanol, heptanol, octanol, cyclopentanol and cyclohexanol, and dialcohols such as ethylene glycol; ethylene oxide, propylene oxide, trimethylene oxide;
Alkylene oxides such as tetrahydrofuran and tetrahydropyran; and peroxides such as propylene peroxide and butene peroxide.

Of these, water or an alcohol having 5 or less carbon atoms is preferable, and water is particularly preferable. As a method of bringing the polyolefin into contact with the ligand decomposer, for example, there is a method of bringing the polyolefin into contact with a gas stream containing the ligand decomposer. In this case, for example, a polyolefin powder is passed through the container while introducing a gas containing a ligand decomposer into the container.

The average particle size of the polyolefin powder when it is brought into contact with the ligand decomposing agent is usually 50 to 5000 μm.
m, preferably 80-3000 μm, more preferably 1
It is in the range of 00 to 2000 μm.

Examples of the gas containing a ligand decomposer include an inert gas such as a nitrogen gas and an argon gas. The gas containing the ligand decomposer usually contains the vapor of the ligand decomposer. The content of the ligand decomposer in the gas containing the ligand decomposer is usually 0.1% by weight to 40% by weight, preferably 0.5% by weight to 20% by weight, particularly preferably 1% by weight to 10% by weight. % Range.

The superficial velocity of the gas containing the ligand decomposing agent is usually 0.01 to 20 cm / sec, preferably 0.1 to 10 cm / sec.
/ S, particularly preferably 0.5 to 5 cm / s. The superficial velocity is based on the temperature and pressure of the ligand-decomposing agent-containing gas at the gas outlet of the device used for bringing the polyolefin into contact with the ligand-decomposing agent, and the cross-sectional area of the device. Is calculated.

When the polyolefin has a degree of crystallinity of 40% or more, the temperature at which the polyolefin is brought into contact with the ligand decomposer is usually not lower than the polyolefin crystallization temperature and lower than the polyolefin decomposition temperature. Specifically, the temperature ranges from 100 to 300 ° C, preferably from 100 to 280 ° C. When the crystallinity of the polyolefin is less than 40%, the melting point of the polyolefin is not lower than −15 ° C. and is lower than the decomposition temperature of the polyolefin.
It is in the range of 5 to 300C, preferably 90 to 280C.

The crystallinity of the polyolefin (X _c )
Is measured by the following method. That is, after preheating the polyolefin at 190 ° C. for 7 minutes, 100 kg / c
pressurized with m ² for 2 minutes, then 20 ° C., 100 kg / cm
^By cooling under the conditions of ² , a 5 mm-thick press sheet is produced. About 5 mg of a test piece (sample) cut out from the press sheet is inserted into an aluminum pan. Using a DSC-II manufactured by Perkin Elmer, measurement is performed from room temperature to 150 ° C. at a rate of temperature increase of 10 ° C./min to obtain an endothermic curve. Separately, the endothermic curve of the sample is converted into the heat of fusion using the weighed indium endothermic curve area. A point at 35 ° C. on the endothermic curve of the sample;
The point where the endothermic peak completely disappears is defined as the baseline. Heat of fusion of 100% polyethylene crystal (26
0 (J / g)), the heat of fusion (A
(J / g)) is defined as the crystallinity (X _c = A / 260).

The pressure is usually 0.0001 to 0.6MP
a, preferably in the range of 0.001 to 0.35 MPa, particularly preferably 0.01 to 0.25 MPa. The contact time (residence time) is usually 1 minute to 3 hours, preferably 2 minutes to 2 hours, particularly preferably 5 minutes to 1 hour.

By contacting the polyolefin with the ligand decomposing agent as described above, the ligand can be decomposed, and the ligand having a high boiling point can be converted to a compound having a low boiling point. Further, depending on the type of ligand, it may be deodorized by decomposition.

Next, in the present invention, the polyolefin which has been brought into contact with the ligand decomposing agent is heated to remove the decomposed ligand in the polyolefin. As a method for removing the ligand by heating the polyolefin which has been brought into contact with the ligand decomposing agent, for example, the following method is available. (1) A method of heating a polyolefin under a flow of an inert gas using a dryer such as a rotary dryer, a belt dryer, a flash dryer, a spray dryer, and a paddle dryer. (2) A method of heating and melting a polyolefin using a single-screw or twin-screw extruder.

When the method (2) is employed, the polyolefin melted by heating may be pelletized, and further, any one of the following steps (b-1) to (b-3) may be carried out. (B-1) a step of bringing the pellets into contact with hot water; (b-2) a step of bringing the pellets into contact with steam; (b-3) a step of bringing the pellets into a range of 0.001 to 0.098 MPa.
When the method of (1) is carried out, the heating temperature of the polyolefin is usually equal to or higher than the crystallization temperature of the polyolefin when the crystallinity of the polyolefin is 40% or more. It is lower than the decomposition temperature, or higher than the crystallization temperature of the polyolefin, and lower than the melting point of the polyolefin, and specifically 100 to 300 ° C, preferably 100 to 280 ° C.

When the crystallinity of the polyolefin is less than 40%, the melting point of the polyolefin is not lower than -15 ° C. and lower than the decomposition temperature of the polyolefin, or the melting point of the polyolefin is not lower than -15 ° C. and not higher than the melting point of the polyolefin; Specifically, 85 to 300 ° C, preferably 90 to 300 ° C
280 ° C. range.

The pressure is usually 0.0001 to 0.6MP
a, preferably in the range of 0.001 to 0.35 MPa, particularly preferably 0.01 to 0.25 MPa. The heating time (residence time) is usually 1 minute to 3 hours, preferably 2 minutes to 2 hours, particularly preferably 5 minutes to 1 hour.

[0049] Examples of the inert gas include nitrogen gas, helium gas, and argon gas. The gas flow rate in the dryer is usually 0.01 to 20 cm / sec, preferably 0.1 to 20 cm / sec.
The range is 1 to 10 cm / sec, particularly preferably 0.5 to 5 cm / sec.

In carrying out the method (2), the heating temperature of the polyolefin is the same as in the method (1). In the present invention, when heating at a temperature equal to or higher than the melting point of the polyolefin and lower than the decomposition temperature in the ligand removal step, it is preferable to perform heating while applying a shearing force to the polyolefin. , A paddle dryer, a single-screw or twin-screw extruder, or the like.

In the present invention, when the method (2) is adopted, the polyolefin melted by heating is pelletized and further subjected to any of the following steps (b-1) to (b-3). Is also good.

Examples of the apparatus that can be used in carrying out the step (b-1) include a countercurrent extraction tower, a storage tank having a stirrer, and a multi-stage horizontal extraction tank.
Devices that can be used in performing the step 3) include silos and hoppers.

In carrying out the step (b-1), the temperature of the hot water is 35 to 200 ° C., preferably 40 to 180 ° C.
Particularly preferably, it is in the range of 45 to 150 ° C., and the contact time is in the range of 1 to 900 minutes, preferably 5 to 600 minutes, particularly preferably 10 to 360 minutes.

In the step (b-2), the water vapor-containing gas is brought into contact with the polyolefin in the same manner as in the ligand decomposition step. Examples of the gas containing water vapor include the same inert gas and air as described above.

The temperature at which the polyolefin is brought into contact with the water vapor-containing gas is such that the crystallinity of the polyolefin is 40%.
In the case of the above, it is usually higher than the crystallization temperature of the polyolefin and lower than the decomposition temperature of the polyolefin, or higher than the crystallization temperature of the polyolefin, and lower than the melting point of the polyolefin, specifically 100 to 300 ° C., preferably It is in the range of 100 to 280 ° C.

When the crystallinity of the polyolefin is less than 40%, the melting point of the polyolefin is −15 ° C. or more and less than the decomposition temperature of the polyolefin, or the melting point of the polyolefin is −15 ° C. or more and the melting point of the polyolefin is not more than Specifically, 85 to 300 ° C, preferably 90 to 300 ° C
280 ° C. range.

The pressure is usually 0.0001 to 0.6MP
a, preferably in the range of 0.001 to 0.35 MPa, particularly preferably 0.01 to 0.25 MPa. The content ratio of water vapor in the water vapor-containing gas is generally in the range of 0.1% to 40% by weight, preferably 0.5% to 20% by weight, and particularly preferably 1% to 10% by weight.

The superficial velocity of the steam-containing gas is usually 0.0
1 to 20 cm / sec, preferably 0.1 to 10 cm / sec,
Particularly preferably, it is in the range of 0.5 to 5 cm / sec. The contact time (residence time) is usually 0.5 to 30 hours, preferably 1 to 24 hours, particularly preferably 2 to 20 hours.

In performing the step (b-3), the pressure is 0.001 to 0.100 MPa, preferably 0.00
7 to 0.098 MPa, particularly preferably 0.01 to 0.1 MPa.
07 MPa, and the temperature is 35 to 200 ° C, preferably 40 to 180 ° C, particularly preferably 45 to 150 ° C.
It is. The heating time is 0.5 to 30 hours, preferably 1 to 24 hours, particularly preferably 2 to 20 hours.

The average particle size of the polyolefin pellets in the case of performing the above steps (b-1) to (b-3) is usually 1 to 30.
mm, preferably 3 to 20 mm, more preferably 5 to 1 mm
It is desirable to be in the range of 5 mm.

More specifically, the method for treating a polyolefin according to the present invention can be carried out, for example, by the steps shown in FIG. 1 or FIG. FIG. 1 is a conceptual diagram illustrating an example of a process of the polyolefin treatment method according to the present invention, and FIG. 2 is a conceptual diagram illustrating another example of a process of the polyolefin treatment method according to the present invention. In the silo indicated by 1 in the figure, a ligand decomposition step was performed,
The ligand removal step is performed in an extruder indicated by, a silo indicated by 4, a dryer indicated by 7.

Hereinafter, an example in which water (steam) is used as the coordinating agent will be described. In the step shown in FIG. 1, polyolefin powder is continuously supplied to the silo 1 from a powder supply pipe 11. In the silo 1, an inert gas containing water vapor is supplied to the silo 1 from a gas supply pipe 12 provided at a lower portion. As a result, the powder of the polyolefin comes into contact with steam, and the ligand contained in the polyolefin is decomposed. The inert gas containing water vapor supplied to the silo 1 is discharged from the gas discharge pipe 14 to the outside of the silo 1.

The polyolefin powder in contact with the water vapor is discharged out of the silo 1 through the powder discharge pipe 13,
Next, it is supplied to the extruder 2. The polyolefin heated and melted by the extruder 2 is cooled with water and pelletized. Thereby, a part of the decomposed ligand contained in the polyolefin is removed. The obtained polyolefin pellets are supplied to the dehydrator 3 through the line 15 together with water, and the dehydrated polyolefin pellets are supplied to the silo 4 through the pellet supply pipe 17. The water separated by the dehydrator 3 passes through the circulation line 16 and is reused as cooling water. In addition, 5 is a water storage tank in the figure, and 6 is a pump.

In the silo 4, an inert gas containing water vapor is supplied to the silo 4 from a gas supply pipe 18 provided below. As a result, the polyolefin pellets and the steam come into contact, and the decomposed ligand contained in the polyolefin is further removed. The inert gas containing water vapor supplied to the silo 4 is discharged from the gas discharge pipe 20 to the outside of the silo 4. The pellet of the polyolefin from which the decomposed ligand has been removed is discharged from the pellet discharge pipe 19.

In the step shown in FIG. 2, as in the step shown in FIG. 1, the polyolefin powder and the inert gas containing water vapor come into contact in the silo 1, and the ligand contained in the polyolefin is decomposed. . The polyolefin powder in contact with the water vapor is discharged from the silo 1 through the powder discharge pipe 13, and then supplied to the dryer 7. In addition,
In FIG. 2, the dryer 7 is a belt dryer, but is not limited to this.

In the dryer 7, heated inert gas is supplied from the gas supply pipe 21, and the polyolefin powder is heated and comes into contact with the inert gas. Thereby, the decomposed ligand contained in the polyolefin is removed. The inert gas supplied to the dryer 7 is discharged from the gas discharge pipe 22.

The polyolefin powder from which the decomposed ligand has been removed is supplied to the crusher 8 through the line 23, crushed and discharged from the discharge pipe 24.

[0068]

Industrial Applicability The present invention decomposes and removes a residual ligand having a cyclopentadienyl skeleton from a polyolefin produced using a transition metal compound containing a ligand having a cyclopentadienyl skeleton. Thus, a polyolefin with less odor during molding can be obtained.

[0069]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

The measurement of the residual amount of the ligand and the evaluation of the odor were performed as follows. Extraction was performed using toluene as the ligand residual amount, and identification and quantification were performed by gas mass using the calibration curve method.

Put 400 g of pellets in a jar having a 1-liter odor content, cover and shake well for 30 seconds. Then open the lid and evaluate the odor.

The odor of the polyolefin measured as described above was evaluated according to the following five grades. When the score was 5 or 4, there was no problem in use. 5 ... no smell 4 ... smells faint 3 ... smells a little 2 ... quite smells 1 ... smells badly

[0073]

Example 1 Obtained using a metallocene compound having 1-methyl-3-butylcyclopentadienyl as a ligand, has a crystallinity of 50%, a crystallization temperature of 101 ° C., a melting point of 117 ° C., and a MI Is 4.0 g / 10 min and the density is 0.920 g
/ Cm ³ , particle size 1100 μm, bulk density 0.420 g
/ Cm ³ was treated as follows in a process as shown in FIG. The residual amount of the ligand of this polyethylene was 500 ppb, and the odor rating was 1.

Ligand Decomposition Agent Contact and Ligand Decomposition Step Steam-containing nitrogen gas was introduced, and the pressure was increased to 0.05 kg / c.
The polyolefin powder was passed through a silo having a m ² -G of 80 ° C. and a residence time of 3 minutes.

At this time, water and polyethylene powder (P
E) and the weight ratio (water / PE) is 0.002,
Raw gas (N_Two) And polyethylene powder (PE) ratio
(N _Two(N-m^Three) / PE (kg)) is 0.004
Was.

First Ligand Removal Step The polyethylene powder having undergone the ligand decomposition step was pelletized at an outlet temperature of 180 ° C. using a twin-screw extruder.

Second Ligand Removal Step Steam-containing air is introduced, and the pressure is set to 1.7 kg / cm ² -G
The polyolefin pellets were passed through a silo at a temperature of 90 ° C. for a residence time of 12 hours.

At this time, the weight ratio of water vapor (water) to polyethylene powder (PE) (water / PE) was 0.018.
And air and polyethylene pellets (PE)
(Air (N-m ³ ) / PE (kg)) was 0.016.

The polyethylene after the treatment as described above was evaluated for the residual amount of the ligand and the odor. Table 1 shows the results.

[0080]

Example 2 In Example 1, polyethylene was treated in the same manner as in Example 1 except that the second ligand removal step was not performed, and the residual polyethylene and odor of the treated polyethylene were measured. evaluated. Table 1 shows the results.

[0081]

Comparative Example 1 Polyethylene was treated in the same manner as in Example 1 except that the ligand decomposition step was not performed, and the treated polyethylene was evaluated for the residual amount of ligand and the odor. Table 1 shows the results.

[0082]

Examples 3 to 7 In Example 1, polyethylene was treated in the same manner as in Example 1 except that the polyethylene was changed to polyethylene shown in Table 1. The residual polyethylene and the odor of the treated polyethylene were measured. Was evaluated. Table 1 shows the results.

[0083]

Example 8 The same polyethylene as used in Example 1 was used, and the polyethylene was treated in the steps shown in FIG.

Ligand Decomposition Step Nitrogen gas containing methanol vapor was introduced, and the polyolefin powder was placed in a silo at a pressure of 0.05 kg / cm ² -G and a temperature of 80 ° C. for a residence time of 3 minutes. Let it pass.

At this time, the weight ratio of methanol to polyethylene powder (PE) (methanol / PE) was 0.1.
0002, and the ratio of nitrogen gas (N ₂ ) to polyethylene powder (PE) (N ₂ (N-m ³ ) / PE (kg)) is
It was 0.004.

The procedure was the same as in the ligand decomposition step of Example 1. The polyolefin pellets were passed through a belt dryer having a ligand removal step temperature of 120 ° C. for a residence time of 1 minute.

The polyethylene after the treatment as described above was evaluated for the residual amount of the ligand and the odor. Table 1 shows the results.

[0088]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of steps of a method for treating a polyolefin according to the present invention.

FIG. 2 is a conceptual diagram showing another example of the steps of the method for treating a polyolefin according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Teruhisa Kojima 1-2-1, Waki, Waki-cho, Kuga-gun, Yamaguchi Prefecture Inside Mitsui Petrochemical Industry Co., Ltd.

Claims (10)

[Claims] (I) contacting a polyolefin obtained by using a transition metal compound containing a ligand having a cyclopentadienyl skeleton with a ligand decomposer; (ii)
Heating the polyolefin contacted with a ligand decomposer. 2. Decomposing a ligand in a polyolefin by contacting a polyolefin obtained using a transition metal compound containing a ligand having a cyclopentadienyl skeleton with a ligand decomposer. And (ii) a ligand removing step of heating the polyolefin contacted with a ligand decomposing agent to remove the decomposed ligand from the polyolefin. Polyolefin treatment method. 3. The method for treating a polyolefin according to claim 2, wherein the ligand decomposer is at least one compound selected from the group consisting of water, oxygen, alcohol, alkylene oxide and peroxide. 4. The method for treating a polyolefin according to claim 2, wherein the average particle size of the polyolefin in the ligand decomposition step is in the range of 50 to 5000 μm. 5. The method for treating a polyolefin according to claim 2, wherein the ligand decomposing step is a step of bringing a gas stream containing the ligand decomposing agent into contact with the polyolefin. 6. The heating temperature in the ligand removal step, wherein the polyolefin has a crystallinity of 40% or more,
When the crystallization temperature of the polyolefin is equal to or higher than the decomposition temperature of the polyolefin, and the crystallinity of the polyolefin is less than 40%,
The method for treating a polyolefin according to claim 2, wherein the melting point of the polyolefin is −15 ° C. or higher and lower than the decomposition temperature of the polyolefin. 7. When the heating temperature in the ligand removing step is such that the degree of crystallinity of the polyolefin is 40% or more,
When the crystallization temperature of the polyolefin is equal to or higher than the melting point of the polyolefin, and the crystallinity of the polyolefin is lower than 40%,
The method for treating a polyolefin according to claim 2, wherein the melting point of the polyolefin is −15 ° C. or higher and the melting point of the polyolefin is lower than the melting point. 8. The ligand removing step wherein the polyolefin contacted with a ligand decomposer is heated while applying a shearing force at a temperature higher than the melting point of the polyolefin and lower than the decomposition temperature. A method for treating a polyolefin according to any one of claims 1 to 5. 9. The ligand removing step includes: (a) heating and melting the polyolefin contacted with a ligand decomposing agent to produce polyolefin pellets; and (b-1)
(B-2) a step of contacting the pellet with steam, and (b-3) a step of maintaining the pellet under a pressure of 0.001 to 0.098 MPa. The method for treating a polyolefin according to any one of claims 2 to 7, which is a step including one step. 10. The polyolefin treatment according to claim 2, wherein the ligand removing step is a step of heating the polyolefin contacted with a ligand decomposing agent under a flow of an inert gas. Method.