JP2706036B2 - Method for producing olefin block copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an olefin block copolymer. More specifically, the present invention relates to a method for producing a block copolymer of an olefin and an unsaturated carboxylic acid ester using an organic rare earth metal compound catalyst having high activity and high activity persistence.

[0002]

2. Description of the Related Art Conventionally, Ziegler catalysts have been widely used as olefin polymerization catalysts. However, even if an attempt is made to copolymerize an olefin with a monomer having a polar group using a Ziegler-based catalyst, the reactivity with a compound having a polar group is high and the catalyst is deactivated, so that it has been difficult to produce a copolymer.

Recently, organic rare earth metal compound catalysts have been proposed as homogeneous catalysts for olefin polymerization. In particular, it has been reported that a catalyst having a cyclopentadiene derivative as a ligand has high activity in the polymerization of olefins, and that this catalyst or a catalyst composed of the catalyst and an organoaluminum compound is used together with a monomer having a polar group. It is reported that the method can also be applied to polymerization (Japanese Unexamined Patent Publication No. 3-2551).
16, JP-A-4-53813), even with these catalysts, the activity and persistence of the activity could not be said to be sufficient.

[0004]

SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of these conventional catalysts, and the catalyst comprising a reaction component of a catalyst component containing an organic rare earth metal compound having a specific structure with a Grignard reagent is an olefin and a catalyst. Even for polar monomers, it has high activity and high activity persistence, and has living polymerizability.After conducting olefin polymerization for a certain period of time,
It has been found that if a polar monomer is introduced, an olefin block copolymer can be produced .

[0005]

SUMMARY OF THE INVENTION Namely, the present invention is represented by the following general formula _{(I) Cp a Nd X b} M c D d in ···· (I) (formula (I), Cp is a substituted cyclopentadienyl The group Nd is neodymium, X is a halogen element M is an alkali metal, D is an ether , a is 1-2, b is 1-2, c is 0-1, and d is 0-3.) A rare earth metal compound and the following general formula (II): RMgX (...) (II) (In the formula (II), R is an alkyl group and X is a halogen element.) A process for producing an olefin block copolymer, comprising copolymerizing an α-olefin having 2 to 10 carbon atoms and at least one unsaturated carboxylic acid ester in the presence of a polymerization catalyst comprising a reaction product with a Grignard reagent. It is.

The present invention also includes a method for producing a block copolymer of an α-olefin and an unsaturated carboxylic acid ester by further adding an organoaluminum compound to the reaction product of the organic rare earth metal compound and the Grignard reagent.

[0007] Cp constituting the organic rare earth metal compound of formula (I) is the location 換Shi cyclopentadienyl group, for example,
Pentamethylcyclopentadienyl group can be suitably used
You.

The rare earth metal constituting the organic rare earth metal compound is neodymium (Nd).

X is a halogen element, particularly chlorine,
Bromine, iodine and the like are preferred.

[0010] The organic rare earth metal compound are those containing as essential components the Cp, Nd and X, may contain alkali metal (M)及beauty ether (D) as an optional component in the other.

[0011] alkali metals (M) can be exemplified lithium, sodium, potassium and the like. The ether
As (D), diethyl ether is particularly preferred.

The following compounds can be exemplified as such organic rare earth metal compounds (I) . Bi scan pentamethylcyclopentadienyl neodymium dichloride lithium bis pentamethylcyclopentadienyl neodymium dichloride sodium bis pentamethylcyclopentadienyl neodymium dichloride potassium及 beauty these <br/> Etera bets like.

The organic rare earth metal compound can be synthesized by known means. A halogen compound of immediate Chi neodymium obtained by reacting an alkali metal compound having a cyclopentadienyl or fused cyclopentadienyl ring group in ether organic solvent such as diethyl ether. For example, bispentamethylcyclopentadienyl neodymium dichloride lithium diethyl etherate is combined with pentamethylcyclopentadienyl lithium and trichloride.
Neodymium can be obtained by refluxing in tetrahydrofuran and then purifying. Further, the organic rare earth compound can be used without purification.

In the present invention, the reaction product of the above organic rare earth metal compound (I) and a Grignard reagent is used as an olefin polymerization catalyst. Grignard reagents are represented by the general formula RMgX (II), where R is an alkyl group and X is a halogen element . As an alkyl group
It is especially an alkyl group having 1 to 6 carbon atoms, for example, ethyl
Groups, butyl groups and hexyl groups are preferred. As the halogen, chlorine, bromine, iodine and the like are particularly preferable.

The mixing ratio of the organic rare earth metal compound to the Grignard reagent varies depending on the kind of the organic rare earth metal compound, but is in the range of 0.01 to 100 mol, particularly 0.1 to 10 mol of the Grignard reagent per mol of the organic rare earth metal compound. Preferably, the reaction is carried out. The reaction is usually performed in an ether solvent,
The reaction is carried out at a reaction temperature of -100 to 200 ° C. In addition, even when the organic rare earth compound and the Grignard reagent are insoluble in the aromatic hydrocarbon, the reaction product is generally soluble in the aromatic hydrocarbon, and its structure has been elucidated by the reaction between the organic rare earth compound and the Grignard reagent. No,
It is considered that a new complex having a catalytic action was formed.

The organic rare earth complex may be used alone, but may also be used by supporting it on an inorganic carrier such as a metal chloride or a metal oxide or a polymer carrier such as polyethylene.

The reaction product of the above-mentioned organic rare earth metal compound and Grignard reagent can be used as it is as an olefin polymerization catalyst, but the activity is further improved by adding an organic aluminum compound as a co-catalyst during the polymerization. Examples of the organic aluminum compound include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum and the like.
Aluminum alkyl, diethyl aluminum chloride
Alkyl aluminum chlorides such as dialkyl aluminum chloride and ethyl aluminum sesquichloride
Skichrolai can be mentioned. The amount of the organoaluminum compound used is preferably 0 to 20 as a molar ratio of aluminum to the rare earth element. Also, two or more kinds of organoaluminum compounds can be used in combination. A product obtained by reacting an organic rare earth metal compound with an organic aluminum compound such as a trialkylaluminum without reacting with a Grignard reagent cannot obtain high polymerization catalyst activity.

The present invention is applicable to a block copolymerization reaction between an α-olefin and at least one unsaturated carboxylic acid. Examples of the olefin include those having 2 to 10 carbon atoms, that is, ethylene, propylene, butene, and 4-methylpentene, with ethylene being particularly preferred. In the present invention, a copolymer of α-olefin, for example, a copolymer of ethylene and propylene, may be subjected to block copolymerization of an unsaturated carboxylic acid ester.

Examples of the unsaturated carboxylic acid ester to be block-copolymerized with an olefin include alkyl esters of unsaturated carboxylic acids such as acrylic acid, methacrylic acid, ethyl acrylic acid, propyl acrylic acid and butyl acrylic acid. As the alkyl group, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, vinyl, allyl, 2-methylallyl, 2-dimethylamino , 2 -dimethylamino
Examples include methoxyethyl, cyclohexyl , 2-chloroethyl, and ethylene glycol groups. Unsaturated carboxylic acid esters which can be particularly preferably used are methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and the like.

The olefin block copolymer of the present invention undergoes the first-stage polymerization in the presence of the catalyst, and stops the supply of the olefin when a certain amount of the olefin polymer is produced.
It is obtained by substituting an unsaturated carboxylic acid ester and conducting the second stage polymerization. The catalyst of the present invention has an activity even after the first stage of olefin polymerization, and has a behavior of living polymerization. Therefore, the unsaturated carboxylic acid ester monomer is further polymerized to the olefin polymer by the introduction of the unsaturated carboxylic acid ester. A block copolymer is obtained.
Generally, as the molecular weight of the olefin moiety increases, the polymerization of the unsaturated carboxylic acid ester becomes difficult.

The polymerization can be carried out in any of solution, suspension, slurry and gas phase, but when it is carried out in a solvent, an inert organic solvent is used. As the solvent, aliphatic hydrocarbons such as pentane, hexane and heptane, aromatic hydrocarbons such as benzene, toluene and xylene, and alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane are preferable. The polymerization can be carried out continuously in two or more polymerization tanks.

The polymerization temperature varies depending on the type of catalyst and the type and properties of the target polymer, but is usually 0 to 20 for each stage.
Performed at 0 ° C. The polymerization can be carried out by any of a continuous method and a batch method. The polymerization pressure in each stage is from normal pressure to 100 kg / cm ² .

The polymerization is carried out in an inert atmosphere. At the stage of olefin polymerization, a chain transfer agent may be added for controlling the molecular weight. Examples of the chain transfer agent include hydrogen, alkyl zinc, and the like.

The total molecular weight of the block copolymer obtained in the present invention and the molecular weight of each polymer segment of olefin and unsaturated carboxylic acid ester can be arbitrarily obtained by controlling the polymerization time and polymerization conditions at each stage. It is preferable that the ratio of the molecular weight of the unsaturated carboxylic acid ester polymer segment to the total molecular weight is 0.01 to 99.9%, particularly 0.01 to 50%.

The product of the polymerization reaction may include, besides the block copolymer, a polymer of an olefin and an unsaturated carboxylic acid ester. These can be separated by solvent extraction. When separating a homopolymer of an unsaturated carboxylic acid ester, it can be extracted and separated using an organic solvent such as chloroform.

The total molecular weight and molecular weight distribution of the block copolymer obtained in the present invention, the molecular weight of each polymer segment, the ratio of the unsaturated carboxylic acid ester polymer segment and the like are determined by GP.
It can be analyzed by C, NMR and the like.

[0027]

[Example 1] (Synthesis of catalyst) A pentamethylcyclopentadienyl lithium (0.034) was placed in a 300 ml flask containing a stirrer sufficiently purged with nitrogen.
mol) and anhydrous neodymium trichloride (0.017 mol). About 180 ml of dry tetrahydrofuran is added,
Refluxed for about 12 hours. After removing tetrahydrofuran under reduced pressure, the residue was extracted with 120 ml of dry diethyl ether. The extraction operation was repeated twice. About 100 ml of extract
Then, the mixture was cooled to -10 ° C and decanted. After further washing with dry diethyl ether to about 10 ml, and dried under reduced pressure to give the ^{_{Cp * 2 NdCl 2 Li (ether}} ) 2 (Cp * represents a pentamethylcyclopentadienyl group).

[0028] was the next thoroughly purged with nitrogen 200ml flask ^{_{Cp * 2 NdCl 2 Li (ether}} ) 2 (1mmol) and placed in dry diethyl ether approximately 100 ml. After cooling with ice water, 0.5 ml (1 mol) of n-BuMgCl-2.0 mol / l diethyl ether solution was added dropwise and stirred for 1 hour. After storing in a refrigerator overnight, diethyl ether was sufficiently removed under reduced pressure at room temperature, and 100 ml of dry toluene was added to obtain a homogeneous catalyst solution.

(Polymerization) 50 ml of dry toluene was introduced into a 100 ml flask containing a stirrer, which had been sufficiently dried and replaced with nitrogen, and was replaced with ethylene. The temperature was raised to 80 ° C., and the above catalyst solution 5 ml (0.05 mmol)
And the polymerization was started at atmospheric pressure under continuous supply of ethylene. The amount of ethylene absorbed 5 minutes after the start of polymerization is 0.05 l / mi.
n, 0.04 l / min after 10 minutes, 0.04 l / m after 15 minutes
was in. Fifteen minutes after the start of the polymerization, the supply of ethylene was stopped, and the inside of the system was sufficiently purged with nitrogen, and then the flask was cooled to room temperature. To measure the properties of the produced polyethylene,
5 ml of the content was sampled from the flask, and the polymer was precipitated with methanol / hydrochloric acid. After filtration, washing and drying, polyethylene was obtained in the form of fine white powder. The molecular weight (Mw) and molecular weight distribution (MWD) of this polyethylene taken out before block copolymerization were determined by GPC (135 ° C., trichlorobenzene, molecular weight in terms of styrene).

Then, 2 ml of purified methyl methacrylate (MMA) was added to the flask, and polymerization was started at room temperature. After 2 hours, the polymerization was stopped by pouring the reaction solution into a large amount of methanol to precipitate a polymer. The polymer was filtered, washed with methanol, dried under reduced pressure, and weighed. The obtained polymer was washed with chloroform for 4 hours.
Soxhlet extraction was performed for a period of time, the chloroform-insoluble portion was taken out, dried and weighed. 710 mg of a white fine powdery ethylene / MMA block copolymer was obtained.

The residual ratio of chloroform extraction was 97.5%, the amount of components separated as chloroform-soluble components was small, and no IR of polyMMA was observed by IR analysis. GPC, ¹³ C-NM
Analyzed by R and infrared absorption spectrum (IR).
According to GPC analysis, the molecular weight was shifted to a higher molecular weight side by copolymerization, and components derived from polyethylene and polyMMA were confirmed by IR. The chloroform-insoluble portion was extracted again by Soxhlet, but the result of IR analysis did not change. As a result of NMR analysis, as shown in FIG. 2, 22.9 ppm (a), 46.5 ppm (b), 51.3 ppm (c), 53.0 ppm
Signals were observed at (d) and 176.3 ppm (e). This is derived from the following carbon of the isotactic poly MMA, and it was found that the MMA polymerization part had a high isotactic structure. The block copolymerization conditions are shown in Table 1, and the properties of the obtained block copolymer are shown in Table 2, together with the properties of the polyethylene taken out before introducing the MMA monomer. Also I
The R and NMR spectra are shown in FIGS.

Example 2 First, ethylene polymerization was carried out in the same manner as in Example 1 except that the temperature was raised to 80 ° C. and then 2.5 ml (0.025 mmol) of a triethylaluminum / toluene solution was added. . Five minutes after the start of polymerization, the ethylene absorption is 0.06 l / mi.
n, 0.06 l / min after 10 minutes, 0.05 l / m after 15 minutes
was in. Then, MMA was polymerized in the same manner as in Example 1,
After post-treatment, 920 mg of an ethylene / MMA block copolymer was obtained. Poly MMA in chloroform soluble part
Was observed. When the chloroform-insoluble portion was measured by IR, peaks derived from polyethylene and polyMMA were confirmed. According to NMR analysis, the MMA polymerization portion has an isotactic structure. The results are shown in Tables 1 and 2.

Example 3 In the catalyst synthesis of Example 1, n-BuMgCl-2.0
mol / l diethyl ether solution in 0.25 ml (0.5 mol
l) Dropwise, therefore n-BuMgCl / Nd complex molar ratio =
A catalyst was synthesized in the same manner as in Example 2 except that the amount was changed to 0.5. As in Example 2, 2.5 ml (0.025 mmol) of a triethylaluminum / toluene solution was added, and ethylene and MM were added.
A is subjected to block copolymerization to obtain a block copolymer 529.
mg was obtained. IR analysis confirmed absorption of polyMMA in the chloroform-soluble portion. Further, peaks derived from polyethylene and polyMMA were confirmed in the chloroform-insoluble portion. Further, NMR analysis revealed that the MMA polymerization portion had an isotactic structure. The amount of ethylene absorbed 5 minutes after the start of ethylene polymerization was 0.04 l / min,
0.03 l / min after 10 minutes, 0.03 l / min after 15 minutes
Met. The results are shown in Tables 1 and 2.

[0034]

[Table 1] Catalyst A: Cp ^* ₂ NdCl ₂ Li (OEt ₂ ) ₂ / nBuMgCl = 1 Catalyst B: Cp ^* ₂ NdCl ₂ Li (OEt ₂ ) ₂ / nBuMgCl = 2

[0035]

[Table 2]

[0036]

The organic rare earth metal compound catalyst of the present invention is a homogeneous catalyst and can block copolymerize an olefin and an unsaturated carboxylic acid ester. The catalyst is highly active and has a long lasting activity. According to the present invention, a modified polymer having a polar group at the terminal of the polyolefin is obtained, so that the coloring property, adhesiveness and conductivity are improved as compared with the olefin homopolymer, a compatibilizer, an antistatic plastics, and an improved adhesiveness. It is useful for applications such as polyolefin resins and polyolefin resins with improved printability. Further, the synthesis of the catalyst is easy, and the obtained catalyst is stable and can be stored for a long time in an inert atmosphere, so that an industrially advantageous method for block copolymerization of an olefin can be provided.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of the olefin block copolymer of the present invention.

FIG. 2 shows ¹³ C- of the olefin block copolymer of the present invention.
NMR spectrum

Claims (2)

(57) [Claims] 1. A following general formula _{(I) Cp a Nd X b} M c D d ···· (I) ( in the formula (I), Cp is a substituted cyclopentadienyl group Nd is neodymium, X is a halogen element M is an alkali metal, D is an ether , a is 1-2, b is 1-2, c is 0-1, d is 0-3) and an organic rare earth metal compound represented by the following general formula ( II) RMgX... (II) (in the formula (II), R is an alkyl group and X is a halogen element). A method for producing an olefin block copolymer, comprising copolymerizing at least one kind of α-olefin having 2 to 10 carbon atoms and at least one kind of unsaturated carboxylic acid ester in the presence of a polymerization catalyst. 2. The reaction product of the organic rare earth metal compound according to claim 1 and a Grignard reagent is a trialkylaluminum.
Chloride, dialkylaluminum chloride or A,
The method for producing an olefin block copolymer according to claim 1, wherein α-olefin and unsaturated carboxylic acid ester are copolymerized in the presence of a polymerization catalyst obtained by adding alkylaluminum sesquichloride .