JP2001172322A - Polyolefin having polar functional group only at terminal of main chain and its preparation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyolefin having a maleic anhydride-derived polar functional group only at the terminal of the main chain and to provide its preparation method. SOLUTION: The polyolefin has a polar functional group of formula (i) or (ii) only at the terminal of the main chain (in formula (ii), X and Y are each a 1-5C alkyl group, a hydrogen atom, an alkali metal or a silyl group). The preparation method of the polyolefin comprises reacting an olefin with maleic anhydride in the presence of a catalyst comprising a specific transition metal complex and an organic aluminum compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a polyolefin having a polar functional group only at the terminal of the main chain and a method for producing the same.

[0002]

BACKGROUND OF THE INVENTION Polyolefins having a polar functional group at the terminal of a molecular chain include, for example, compatibilizers for polymer blends, paint improvers for paints, paint improvers and adhesion improvers for polyolefins, and agents for molecular design. It is useful as a raw material.

[0003] Such a polyolefin having a polar functional group at the terminal of a molecular chain is prepared, for example, by combining a polyolefin and a compound having a functional group structure such as an unsaturated carboxylic acid in the presence of a polymerization initiator such as an organic peroxide. It can be manufactured by a method of melt-kneading. However, in such a method, it is difficult to adjust the introduction amount of the functional group, and it is difficult to obtain a modified polyolefin having uniform properties. Further, since the obtained modified polyolefin has a double bond structure, it is susceptible to modification such as deterioration by oxygen.

By the way, among polyolefins having polar functional groups at the terminal of the molecular chain, those having polar functional groups, for example, functional groups derived from unsaturated carboxylic acid only at the terminal of the main chain, are homogeneous because of their uniform properties. Excellent performance can be expected as a solubilizer, a coating improver and the like. A polyolefin having a polar functional group only at the terminal of the main chain is particularly useful as a raw material for molecular design. However, when trying to introduce a polar functional group such as a functional group derived from an unsaturated carboxylic acid into a polyolefin by a conventional method, it has been difficult to stop the reaction with one terminal functional group molecule per polymer molecule. Further, a method for directly producing a polyolefin having a functional group derived from an unsaturated carboxylic acid only at the terminal of the main chain by polymerization has not been known.

Under these circumstances, the present inventors have conducted intensive studies. As a result, when an olefin is reacted with maleic anhydride in the presence of a catalyst containing a specific transition metal complex, only the terminal of the main chain is reduced. To obtain a polyolefin having a functional group derived from an unsaturated carboxylic acid. Further, such a polyolefin having a functional group derived from an unsaturated carboxylic acid only at the terminal of the main chain has excellent performance as a compatibilizer, a coating improver, and is useful as a raw material in molecular design. The present inventors have found that the compound has no double bond in the molecule and is hardly denatured by deterioration such as oxygen, and completed the present invention.

[0006]

It is an object of the present invention to provide a polyolefin having a polar functional group derived from maleic anhydride only at the terminal of the main chain, and to provide a method for producing such a polyolefin. I do.

[0007]

The polyolefin according to the present invention has the following formula (i) or (ii)

[0008]

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(In the formula (ii), X and Y may be the same or different and each represents an alkyl group having 1 to 5 carbon atoms, a hydrogen atom, an alkali metal or a silyl group.)
Is characterized by having a polar functional group represented by at only the terminal of the main chain.

The process for producing a polyolefin having a polar functional group represented by the above formula (i) only at the terminal of the main chain according to the present invention comprises: (A) a transition metal complex represented by the following general formula (iii): And (B) a reaction of an olefin with maleic anhydride in the presence of a catalyst comprising an organoaluminum compound.

[0011]

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(Wherein M represents iron, cobalt, ruthenium or rhodium, Rs may be the same or different, and each represents a hydrogen atom or an alkyl group;
Represents an aryl group which may be the same or different and may have a substituent. The method for producing a polyolefin having a polar functional group represented by the above formula (ii) only at the terminal of the main chain according to the present invention has the functional group represented by the above formula (i) only at the terminal of the main chain. It is characterized by reacting a polyolefin with one compound selected from alcohols, alkali metal salts and alkylating agents.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The polyolefin having a polar functional group only at the terminal of the main chain and the method for producing the same according to the present invention will be specifically described below.

The polyolefin according to the present invention has a polyolefin structure as a basic skeleton, and has a polar functional group represented by the following formula (i) or (ii) only at the terminal of the main chain, preferably only at one terminal of the main chain. Having a group.

[0015]

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In the above formula (ii), X and Y may be the same or different and represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkali metal or a silyl group.

The alkyl group having 1 to 5 carbon atoms includes
Methyl, ethyl, propyl, etc., as the alkali metal, sodium, potassium, etc., as the silyl group, methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, diphenylmethylsilyl, triphenylsilyl , Dimethylphenylsilyl, dimethyl-t-butylsilyl, dimethyl (bendafluorophenyl) silyl and the like.

The polyolefin structure serving as the basic skeleton is formed from repeating units derived from an olefin selected from olefins having 1 to 20 carbon atoms. Here, as the olefin having 1 to 20 carbon atoms, ethylene,
Propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl- 1-hexene,
4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene,
Linear or branched such as 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene Olefins; cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, 2-methyl-1,4,5,8-dimethano-1,2,3,4,
And cyclic olefins such as 4a, 5,8,8a-octahydronaphthalene.

The polyolefin structure serving as the basic skeleton may be composed of only one type of repeating unit derived from the above-mentioned olefin, or may be composed of two or more types. Further, the polyolefin structure serving as the basic skeleton is preferably linear, but may have a branch.

In the present invention, the polyolefin structure serving as the basic skeleton includes polyethylene, polypropylene, ethylene-
A propylene random copolymer is preferred. The polyolefin having the polar functional group according to the present invention only at the terminal of the main chain has a number average molecular weight of usually 100 to 100,000, particularly 1,
It is preferably in the range of 000 to 10,000.

Further, the polyolefin having the polar functional group according to the present invention only at the terminal of the main chain has no double bond in the molecule, and therefore is not easily denatured by deterioration such as oxygen, and is not thermally degraded. Stable.

Production Method The polar functional group represented by the above formula (i) is added only to the terminal of the main chain,
Preferably, the polyolefin having only one terminal of the main chain is obtained, for example, by copolymerizing an olefin and maleic anhydride in the presence of a catalyst comprising the following transition metal complex (A) and an organoaluminum compound (B). Can be manufactured.

The transition metal complex (A) used in the present invention includes a compound represented by the following general formula (iii).

[0024]

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In the formula (iii), M represents iron, cobalt, ruthenium or rhodium, with cobalt being preferred. R is
May be the same or different, and may have 1 to 5 carbon atoms, preferably 1 to 3 alkyl groups such as methyl and ethyl;
Indicates a hydrogen atom and the like.

Ar is the same or different, and represents an aryl group which may have a substituent such as phenyl, 2,6-dimethylphenyl, 2,6-isopropylphenyl, mesityl and the like.

As a preferred transition metal complex represented by the above general formula (iii), M is cobalt,
A compound wherein R is methyl and Ar is mesityl, a compound wherein M is cobalt and R is methyl and Ar is phenyl, a compound wherein M is cobalt, R is a hydrogen atom and Ar is mesityl Compounds, compounds in which M is cobalt, R is a hydrogen atom, and Ar is phenyl, compounds in which M is iron, R is methyl, and Ar is mesityl, are exemplified.

As the organic aluminum compound (B),
An organoaluminum compound represented by the following general formula (iv),
Aluminoxane and the like can be mentioned. R ¹ _n AlX ¹³ _3-n (iv) wherein R ¹ has ¹ to 15 carbon atoms, preferably 1 to 4 carbon atoms.
X ¹ represents a halogen atom or a hydrogen atom, and n is 1 to 3.

Examples of such a hydrocarbon group having 1 to 15 carbon atoms include an alkyl group, a cycloalkyl group and an aryl group, and specific examples include methyl, ethyl, n-propyl, isopropyl and isobutyl. , Pentyl, hexyl, octyl, cyclopentyl, cyclohexyl, phenyl, tolyl and the like.

Specific examples of the organoaluminum compound represented by the general formula (iv) include the following compounds. Trimethylaluminum, triethylaluminum, triisopropyl aluminum, triisobutyl aluminum, trioctyl aluminum, trialkyl aluminum such as tri-2-ethylhexyl aluminum; formula _{(i-C 4 H 9)} x Al y (C 5 H 10) z ( Wherein x, y, and z are positive numbers and z ≧ 2x); alkenyl aluminum such as isoprenyl aluminum; trialkenyl aluminum such as triisopropenyl aluminum; dimethyl aluminum chloride; diethyl aluminum Dialkylaluminum halides such as chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, and dimethylaluminum bromide; methylaluminum sesquichloride, ethylaluminum chloride Alkyl aluminum sesquihalides such as chloride, isopropyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquibromide; alkyl aluminum dihalides such as methyl aluminum dichloride, ethyl aluminum dichloride, isopropyl aluminum dichloride, ethyl aluminum dibromide; diethyl aluminum hydride; Dialkylaluminum hydrides such as dibutylaluminum hydride; alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride.

The aluminoxane (also referred to as an organic aluminum oxy compound or alumoxane) may be a conventionally known aluminoxane or a benzene-insoluble organic aluminum oxy compound.

The conventionally known aluminoxane is specifically represented by the following general formula.

[0033]

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(In the above general formula, R is a hydrocarbon group such as methyl, ethyl, propyl and butyl, preferably methyl and ethyl, particularly preferably methyl, and m
Is an integer of 2 or more, preferably 5 to 40. Here, the aluminoxane has an alkyloxyaluminum unit represented by the formula (OAl (R ¹ )) and a formula (OA)
The alkyloxyaluminum unit represented by 1 (R ² ) (where R ¹ and R ² can be the same hydrocarbon groups as R, and R ¹ and R ² represent different groups. ) May be formed from the mixed alkyloxyaluminum unit.

Specific examples of the aluminoxane include methylaluminoxane. As the organic aluminum compound (B), it is preferable to use aluminoxane.

Examples of the olefin used for the polymerization include olefins having 1 to 20 carbon atoms as described above, and these can be used alone or in combination of two or more. Of these, ethylene, propylene or a combination thereof is preferred.

The polymerization is usually carried out in a liquid phase, and specific examples of the inert hydrocarbon medium used in the polymerization include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane and kerosene. Alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene and dichloromethane or mixtures thereof. And the olefin itself can be used as the solvent. Of these, aliphatic hydrocarbons and alicyclic hydrocarbons are preferred.

The concentration of the transition metal complex (A) during the polymerization reaction is usually from 0.01 to 100 mmol, preferably from 0.5 to 100 mmol, in terms of transition metal atom, per liter of polymerization volume.
2 mmol. The concentration of the organoaluminum compound (B) is usually 0.001 to 10 mol, preferably 0.05 to 10 mol, in terms of aluminum atom, per liter of polymerization volume.
0.2 mol.

The concentration of maleic anhydride during the polymerization reaction is generally 0.1 to 10% by weight, preferably 0.5 to 2% by weight, based on the solvent used. The polymerization is preferably at -78.
The reaction is performed at a temperature of ２５０250 ° C., more preferably -30-100 ° C. The polymerization pressure is preferably between 0.5 and 64 bar, preferably between 1 and 10 bar. In addition, in the case of polymerization or copolymerization of ethylene, the above pressure can be set by supplying ethylene gas to the polymerization system.

At the time of the polymerization reaction, the olefin and maleic anhydride may be simultaneously added to the reaction system, or maleic anhydride may be added to the polymerization system after the polymerization of the olefin has started.

By the above method, a polyolefin having the polar functional group represented by the formula (i) according to the present invention only at the terminal of the main chain, preferably at only one terminal of the main chain (the terminal polar functional group polyolefin) (I)) is obtained, and the polyolefin is a polyolefin containing no polar functional group (for example, a polyolefin having a vinyl group at a terminal)
In some cases. In this case, a polyolefin having a polar functional group only at the terminal of the main chain and a polyolefin containing no polar functional group may be separated by a chemical method.

The polyolefin having the polar functional group represented by the above formula (ii) only at the terminal of the main chain is, for example, a compound selected from alcohols, alkali metal salts and alkylating agents, and a polyolefin having a terminal polar functional group. (I)
Can be produced by reacting

As the alcohol used for the reaction with the terminal polar functional group polyolefin (i), alcohols having 1 to 5, preferably 1 to 3 carbon atoms, such as methanol, ethanol and propanol, are used. These alcohols can be used alone or in combination of two or more.

As the alkali metal salt used for the reaction with the terminal polar functional group polyolefin (i), sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, potassium carbonate and the like are used. These alkali metal salts are
One type may be used alone, or two or more types may be used in combination.

As the alkylating reagent used in the reaction with the terminal polar functional group polyolefin (i), methyl iodide, ethyl iodide, trimethylsilyldiazomethane and the like are used. These alkylating agents can be used alone or in combination of two or more.

The reaction between the terminal polar functional group polyolefin (i) and the alcohol is carried out by stirring the terminal polar functional group polyolefin (i) and the alcohol in a solvent. At this time, the solvent is preferably 100 to 10,000 based on the weight of the terminal polar functional group polyolefin (i).
The alcohol is preferably used in an amount of 10 to 1000 times, more preferably 500 to 5000 times the weight of the terminal polar functional group polyolefin (i).
More preferably, it is used at a weight of 50 to 500 times. The reaction temperature is preferably 0 to 200 ° C, more preferably 2 to 200 ° C.
5-100 ° C. The reaction pressure is preferably 0.5 to
It is 50 bar, more preferably 1 to 10 bar. As the solvent, a hydrocarbon solvent such as hexane, heptane, benzene, and toluene is used, and alcohol used for the reaction may be used as the solvent. When the terminal polar functional group polyolefin (i) is reacted with an alcohol, a polyolefin having a polar functional group in which X and Y are alkyl groups in the above general formula (ii) only at the terminal of the main chain is obtained.

The reaction between the terminal polar functional group polyolefin (i) and the alkali metal salt is carried out by stirring the terminal polar functional group polyolefin (i) and the alkali metal salt in a solvent. At this time, the solvent is preferably 100 to 1000 with respect to the weight of the terminal polar functional group polyolefin (i).
It is used at a weight of 0 times, more preferably 500 to 5000 times, and the alkali metal salt is preferably 10 to 1000 times with respect to the weight of the terminal polar functional group polyolefin (i).
Twice, more preferably 50 to 500 times the weight. The reaction temperature is preferably from 0 to 200C, more preferably from 25 to 100C. The reaction pressure is preferably between 0.5 and 50 bar, more preferably between 1 and 10 bar. As the solvent, hexane, heptane, benzene,
A hydrocarbon solvent such as toluene is used. When the terminal polar functional group polyolefin (i) is reacted with an alkali metal salt, a polyolefin having polar functional groups in which X and Y are alkali metals in the above general formula (ii) only at the terminal of the main chain is obtained. When reacting the terminal polar functional group polyolefin (i) with an alkali metal salt, methanol, ethanol, isopropanol,
Alcohols having 1 to 5 carbon atoms such as tert-butanol or a mixture of these alcohols and the above-mentioned hydrocarbon solvents can be used. In this case, the above-mentioned general formula (ii)
In the above, a polyolefin having a polar functional group in which X and Y are an alkali metal and / or an alcohol at only the terminal of the main chain is obtained.

The reaction between the terminal polar functional group polyolefin (i) and the alkylating agent is carried out by stirring the terminal polar functional group polyolefin (i) and the alkylating agent in a solvent. At this time, the solvent is preferably 10 to 10,000 based on the weight of the terminal polar functional group polyolefin (i).
The alkylating agent is preferably used at a weight of 10 to 1000 times, more preferably 50 to 500 times the weight of the polymer. The reaction temperature is preferably from 0 to 20.
The temperature is 0 ° C, more preferably 25 to 100 ° C. The reaction pressure is preferably between 0.5 and 50 bar, more preferably between 1 and 50 bar.
-10 bar. As the solvent, hexane, heptane, benzene, toluene and the like are used. It is to be noted that an alkali metal salt may be present in the reaction in an equimolar equivalent amount with respect to the alkylating agent. When the alkali metal salt is present, the reaction between the terminal polar functional group polyolefin (i) and the alkylating agent may occur. Speed is improved. When the terminal polar functional group polyolefin (i) is reacted with the alkylating agent, a polyolefin having polar functional groups in which X and Y are alkyl groups in the above general formula (ii) only at the terminal of the main chain is obtained.

Thus, alcohols, alkali metal salts,
By reacting an alkylating agent or the like with a polar functional group represented by the above formula (i) at the end of the main chain of the polyolefin, an ester, carboxylic acid,
A polyolefin having a polar functional group such as a carboxylate is obtained.

By the above method, a polyolefin having the polar functional group represented by the above formula (ii) according to the present invention at only the terminal of the main chain can be obtained, but this polyolefin does not contain any polar functional group. It may be obtained as a mixture with a polyolefin (for example, a polyolefin having a vinyl group at a terminal). In this case, a polyolefin having a polar functional group only at the terminal of the main chain by a chemical method,
What is necessary is just to isolate | separate from the polyolefin which does not contain a polar functional group at all.

The structure of the polyolefin having a polar functional group represented by the above formula (i) or (ii) only at the terminal of the main chain obtained as described above is confirmed by IR and ¹ H-NMR. be able to.

[0052]

EFFECTS OF THE INVENTION The polyolefin having a polar functional group derived from maleic anhydride only at the terminal of the main chain according to the present invention is a compatibilizer for a polymer blend, a coatability improver for a paint, a coatability improver for a polyolefin, and an adhesive. It has excellent performance as a property improver and is useful as a raw material in molecular design. Further, such a polyolefin can be used as a molding material for containers, films, and the like.

The production method according to the present invention can produce a polyolefin having a functional group derived from maleic anhydride only at the terminal of the main chain, which cannot be obtained by the conventional method.

[0054]

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

[0055]

Example 1 In a 100 ml flask purged with argon, 26.4 mg (0.0 mg) of a compound A represented by the following formula was added.
5 mmol) and 50 ml of toluene, and the system was further replaced with ethylene. The toluene solution containing the compound A was stirred with a magnetic stirrer, and a toluene solution of methylaluminoxane (1.21 mol / L) was added to the solution.
0 ml was added, followed by 500 mg of maleic anhydride. The reaction was carried out for 24 hours under an ethylene gas atmosphere while maintaining the temperature at 25 ° C. Methanol 1
The mixture was poured into a mixture of 1 liter and 2 ml of concentrated hydrochloric acid to precipitate a product, which was filtered, completely dissolved in 100 ml of toluene at 110 ° C., and subjected to a washing operation for reprecipitation.
After being performed twice, it was dried. The yield of the obtained product (polyethylene (1)) was 372 mg.

The analysis of polyethylene (1) was performed by IR, and the absorption (1783 cm ^-1 , 1742-1719 cm) derived from carboxylic anhydride, ester and carbonyl of carboxylic acid was analyzed.
^-1 ) was confirmed. FIG. 1 shows an IR spectrum of polyethylene (1).

[0057]

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[0058]

Example 2 The entire amount of polyethylene (1) obtained in Example 1 was placed in a 500 ml flask,
The mixture was stirred at room temperature for 2 days with 00 ml of methanol and 2 mmol of hydrogen chloride gas. After the solvent was distilled off, the inside of the reactor was replaced with argon, 200 ml of toluene and 1 mmol of trimethylsilyldiazomethane were added, and the mixture was reacted at 40 ° C. for 6 hours. After the solvent was distilled off, the product was washed with methanol and dried. The yield of the product (polyethylene (2)) was 350 mg.

The analysis of polyethylene (2) was carried out by IR, ¹ H-NM.
Performed with R. FIGS. 2 and 3 show the I of polyethylene (2).
R spectrum and ¹ H-NMR spectrum are shown, respectively.
FIG. 4 shows the ¹ H-NMR spectrum of a sample represented by the following formula (vii).

In the IR spectrum of polyethylene (2) shown in FIG. 2, absorption derived from the carbonyl of the ester was observed at 1748 cm ^-1, and absorptions derived from the carbonyl of other carboxylic anhydrides, carboxylic acids and carboxylate salts were observed. I can't. In the ¹ H-NMR spectrum of polyethylene (2) shown in FIG. 3, the chemical shift value, the peak splitting pattern and the comparison with the ¹ H-NMR spectrum of the sample shown in FIG. Peaks determined to be ester methylene at the α-position, methine at the ester α-position, methylene at the α-position of the vinyl group, methylene in the polyethylene main chain, and methyl at the polyethylene terminal are observed, and the integrated intensity ratio is :::::
:: = 1: 0.63: 0.21: 0.10: 0.
67: 64.6: 1.32. Since the sum of “integrated intensity of” and “１ ／ of the integrated intensity of” is “integrated intensity of”, polyethylene (2) is a compound of the compounds represented by the following formulas (v) and (vi). The mixture is determined to be a mixture (the molar ratio of the compound represented by the formula (v) to the compound represented by the formula (vi) is 24:76). At this time, the intensities of the other peaks are explained without contradiction.

[0061]

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From FIG. 3, it was determined that (mol number of methyl ester / total mole number of methylene) was 0.0065, which indicates that the number average molecular weight was 1030.

From the above results, it is considered that the polyethylene (1) obtained in Example 1 is a polyethylene having a polar functional group represented by the above formula (i) at only one terminal of the main chain.

[Brief description of the drawings]

FIG. 1 is an IR spectrum of the polyolefin obtained in Example 1.

FIG. 2 is an IR spectrum of the polyolefin obtained in Example 2.

[Figure 3] of polyolefin obtained in Example 2 ¹ H-
It is an NMR spectrum.

FIG. 4 is a ¹ H-NMR spectrum of a sample.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor ▲ Taka ▼ Yukihiro Ki 580-32 Takuji, Nagaura, Sodegaura-shi, Chiba Prefecture Inside Mitsui Chemicals, Inc. 580-32, Mitsui Chemicals, Inc. (72) Inventor Narumi Matsui, Inventor Mitsui Chemicals, Inc. (72) Mitsui Chemicals, Inc. (72) Inventor Terunori Fujita Chiba 580-32, Takuji, Nagaura-shi, Sodegaura-shi, Japan F-term (reference) in Mitsui Chemicals, Inc. EC02 FA01 FA02 FA07 4J100 AA02P AA03P AA04P AA07P AA09P AA15P AA16P AA17P AA18P AA19P AA21P AK32Q AR03P AR04P AR09P AR11P BA16H BA17H BA20H BA72H CA01 CA04 CA05 CA37 DA01 HC10 HB 9 HC28 HC77 JA01

Claims (4)

[Claims] (1) The following formula (i): A polyolefin having a polar functional group represented by the formula only at the terminal of the main chain. 2. The following general formula (ii): (Wherein, X and Y may be the same or different from each other, and represent an alkyl group having 1 to 5 carbon atoms, a hydrogen atom, an alkali metal or a silyl group). Polyolefin characterized by having only at the end of the chain. 3. An olefin is reacted with maleic anhydride in the presence of a catalyst comprising (A) a transition metal complex represented by the following general formula (iii) and (B) an organoaluminum compound. 1. A method for producing a polyolefin having a polar functional group only at the terminal of the main chain, which comprises producing the polyolefin according to 1. (Wherein, M represents iron, cobalt, ruthenium or rhodium, and Rs may be the same or different from each other;
Ar represents a hydrogen atom or an alkyl group, and Ar represents an aryl group which may be the same or different and which may have a substituent. ). 4. The following formula (i): Reacting a polyolefin having a polar functional group represented only by the terminal of the main chain with one compound selected from an alcohol, an alkali metal salt and an alkylating agent,
The following general formula (ii) (Wherein, X and Y may be the same or different from each other, and represent an alkyl group having 1 to 5 carbon atoms, a hydrogen atom, an alkali metal or a silyl group). A method for producing a polyolefin having a polar functional group only at the end of the main chain, comprising producing a polyolefin having only a chain end.