JP2805841B2 - Ethylene-α-olefin copolymer and method for producing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ethylene-1-butene copolymer and a method for producing the same. More specifically, the present invention relates to an ethylene-1-butene copolymer having excellent transparency and excellent low-temperature heat sealing performance, and a method for producing the same.

<Conventional Technology> Ethylene-α-olefin copolymers have excellent properties such as heat resistance, weather resistance, and ozone resistance, and are therefore used in automotive materials, building materials, industrial materials, and resin modified materials. It is widely used as a quality material. In particular, the demand for ethylene-α-olefin copolymers having a high ethylene content, such as packaging films, has recently been increasing as soft resins having intermediate properties between rubber and crystalline plastics. Among them, a copolymer obtained by copolymerizing ethylene and an α-olefin using a titanium-based polymerization catalyst is known as linear low-density polyethylene (LLDPE), and is widely used. However, when it is used as a film, it is not always satisfactory in terms of heat sealability at low temperatures or transparency.

Thus, the reason why the transparency and heat sealing properties of the ethylene-α-olefin copolymer produced by the titanium-based catalyst are insufficient is that ethylene and α-
It is considered that the distribution of the olefin composition is non-uniform and the molecular weight distribution is wide.

On the other hand, some methods for producing an ethylene-α-olefin copolymer using a vanadium compound as a catalyst have been proposed.

For example, Japanese Patent Publication No. 46-21212 discloses a method in which ethylene and an α-olefin are solution-polymerized using a catalyst comprising a combination of a vanadium compound and an organoaluminum compound. However, according to this method, the produced copolymer can be dissolved in the polymerization solvent and produced as a uniform solution.However, the vanadium compound used in the method has a greatly reduced polymerization activity when the polymerization temperature is increased. ,
As shown in Examples in the publication, in a high temperature region such as 100 ° C., only a very low polymerization activity is practically obtained, and the obtained copolymer has a wide molecular weight distribution, and is extracted with a solvent. Ethylene-α-olefin copolymer containing a large amount of the components.

JP-B-47-26185 discloses a catalyst system comprising a combination of a VOX ₃ compound and an organoaluminum compound using a halogenated lower aliphatic hydrocarbon or a hydrocarbon having 3 to 5 carbon atoms as a solvent for the polymerization reaction. Which discloses a method for producing a copolymer of ethylene and an α-olefin.
In the polymerization method in a halogenated hydrocarbon, the resulting polymer precipitates as an insoluble component and forms an insoluble mixture (slurry) with a polymerization solvent, so that the viscosity of the system decreases, and in terms of stirring and transfer, Although it is economical, there are problems in terms of corrosion of the device due to halogen generated by decomposition of the halogenated hydrocarbon in the solvent and storage stability. In the case of slurry polymerization in a hydrocarbon solvent having 3 to 5 carbon atoms,
This solvent has a boiling point close to that of an α-olefin to be copolymerized with ethylene, particularly propylene or 1-butene, and separation of the unreacted monomer and the polymerization solvent is a major problem in the purification step. In addition, hydrocarbons having 3 to 5 carbon atoms have a low boiling point, require refrigeration equipment for liquefaction, pressure-resistant equipment for the apparatus, and the like. Further, it is necessary to use a refrigerant. It was not advantageous, and there were many problems such as a large-scale facility required for a deashing step for removing the catalyst component taken into the polymer particles produced.

Japanese Patent Publication No. 55-24447 discloses ethylene and 1-
Ethylene with an ethylene content of 85 to 95 mol% from butene
In producing the 1-butene copolymer, an aliphatic hydrocarbon having 6 to 15 carbon atoms is used as a polymerization solvent, and a polymerization temperature of -20 ° C to 30 ° C is used using a catalyst comprising a soluble vanadium compound and an organic aluminum halide. A method of manufacturing at C is disclosed. Similarly, in JP-A-63-17912, ethylene and an α-olefin are copolymerized at a polymerization temperature of −20 ° C. to 30 ° C. using a catalyst comprising a soluble vanadium compound and an organic chlorinated aluminum compound. A method is disclosed. In each of these methods, slurry polymerization is performed. In the former, the molar ratio of Al / V atoms is 2
However, although the latter has a difference in the molar ratio of Al / V atoms of 55 to 170, all of them carry out polymerization at a relatively low temperature of -20 ° C to 30 ° C. There are disadvantages, such as the need for refrigeration equipment drive energy, and the low reaction rate increases the total volume of the reaction tank in order to prolong the residence time in the reaction tank. There were problems such as consuming a large amount of power.

<Problems to be Solved by the Invention> An ethylene-1-butene copolymer having a high ethylene content is subjected to a slurry polymerization method, that is, a part of the copolymer is insoluble in a solvent, and the insoluble copolymer is used. When produced by a polymerization method such that the copolymerization reaction proceeds in a precipitated state, the conventional method requires selection of an appropriate solvent, and
Since low temperature polymerization is required, it is disadvantageous in terms of equipment and energy.

On the other hand, when producing by a solution polymerization method, that is, a polymerization method in which the copolymerization proceeds in a state where all of the copolymer is dissolved in a solvent, polymerization at a relatively high temperature is required, and the catalyst efficiency is reduced. In addition, it is disadvantageous in terms of cost. For this reason,
It has been strongly desired to realize a slurry polymerization method at an intermediate temperature, which is advantageous in terms of equipment, energy, and cost, specifically at around 40 ° C. to 65 ° C. at which the polymerization activity of the vanadium catalyst becomes the highest. However, as a method similar to this method,
In the polymerization method even in the state where the proposed solvent-insoluble polymer and solvent-soluble polymer coexist, for example, as described in JP-B-46-11028, the composition of the obtained copolymer becomes very non-uniform and the molecular weight distribution is also low. There was a problem that the strength and transparency of the polymer were poor.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and provide a method for producing an ethylene-1-butene copolymer having a narrow molecular weight distribution and a uniform composition by a slurry polymerization method which is advantageous in terms of equipment, energy, and cost. Is to provide.

Yet another object is to achieve a narrow molecular weight distribution, uniform composition,
Accordingly, it is an object of the present invention to provide an ethylene-1-butene copolymer which is excellent in transparency and low-temperature heat sealing performance and has a low solvent extraction component.

<Means for Solving the Problems> The present inventors have intensively studied a method for producing an ethylene-1-butene copolymer having a narrow molecular weight distribution and a uniform composition. As a result, as the catalyst system, a vanadium compound having a specific structure, an organoaluminum compound having a specific structure, and a ternary system of a halogenated ester compound having a specific structure are used, and their ratio is limited. Furthermore, by appropriately selecting the copolymerization temperature and the molar ratio of ethylene and 1-butene to be supplied and the copolymerization solvent, slurry polymerization with a low viscosity can be carried out at the copolymerization temperature, and after the completion of the copolymerization, a slightly higher In a process that can be handled as a homogeneous solution and is easy to demineralize, ethylene-1 has a narrow molecular weight distribution, a uniform composition, excellent transparency and heat sealability, and a low solvent extraction component. -Butene copolymer was found to be obtained, and the present invention has been achieved.

That is, of the present invention, one of the inventions comprises ethylene and 1
-Butene, the molar ratio of ethylene / 1-butene content is 88/12 to 98/2, the value of the number average molecular weight by GPC measurement is 35,000 to 80,000, and the weight average molecular weight / number average molecular weight The ratio relates to an ethylene-1-butene copolymer having a ratio of 1.8 to 3.0.

Another invention is a vanadium compound represented by VO (OR) _n X _3-n (where R is a hydrocarbon group, X is a halogen, and 0 ≦ n ≦ 3), R ′ _m AlX _{3 -m} (where R 'represents a hydrocarbon group, X represents a halogen, and 1 ≦ m ≦ 3). (Provided that R ″ is an organic group in which some or all of the hydrogen atoms of a hydrocarbon group having 1 to 20 carbon atoms are substituted with halogen;
R represents a hydrocarbon group having 1 to 20 carbon atoms. Wherein the molar ratio of organoaluminum compound / vanadium compound is 2.5 or more, and the molar ratio of halogenated ester compound / vanadium compound is 1.
Using a catalyst system of 5 or more, the molar ratio of ethylene / 1-butene to be supplied was 35/65 to 60/40, and the copolymerization temperature was 40 ° C to 80 ° C.
° C., in a system in which a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist, ethylene and 1-butene are copolymerized, and the resulting ethylene-1-butene copolymer has an ethylene / 1-butene content of The molar ratio is 88/12 to 98/2, the value of the number average molecular weight of the ethylene-1-butene copolymer measured by GPC is 35,000 to 80,000, and the ratio of weight average molecular weight / number average molecular weight is 1.8 to 3.0,
The present invention relates to a method for producing an ethylene-1-butene copolymer.

In the present invention, the copolymerization of ethylene-1-butene is performed in a system in which a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist, in other words, a solution state and a particle size of 0.5 m.
m is used in a system in which fine particles having a particle size of m or less are in a mixed state. While exhibiting low viscosity as a characteristic of the system, it has a characteristic that a homogeneous solution is obtained at 70 ° C. or higher.

In the present invention, it is important to select a combination of each component of the catalyst system, a copolymerization solvent, and a copolymerization temperature.

The vanadium compound as a catalyst component has a general formula
VO (OR) _n X _3-n (where R is a hydrocarbon group, X is a halogen, and 0 ≦ n ≦ 3), VOCl ₃ , V
O (OCH ₃ ) Cl ₂ , VO (OCH ₃ ) ₂ Cl, VO (OCH ₃ ) ₃ , VO (OC ₂
H ₅ ) Cl ₂ , VO (OC ₂ H ₅ ) ₂ Cl, VO (OC ₂ H ₅ ) ₃ , VO (OC
_{3 H 7) Cl 2, VO} (OC 3 H 7) 2 Cl, VO (OC 3 H 7) 3, VO (OisoC
_{3 H 7) Cl 2, VO} (OisoC 3 H 7) 2 Cl, VO (OisoC 3 H 7) 3, or can be exemplified mixtures thereof. Among them, those other than VOCl ₃ can be easily obtained by reacting VOCl ₃ with alcohol or reacting VOCl ₃ with VO (OR) ₃ .

Of these compounds, VOCl ₃ , V represented by 0 ≦ n ≦ 1
O (OCH ₃ ) Cl ₂ , VO (OC ₂ H ₅ ) Cl ₂ , VO (OC ₃ H ₇ ) Cl ₂ , VO
(OisoC ₃ H ₇ ) Cl ₂ is preferably used for obtaining a copolymer having a narrow molecular weight distribution and a uniform composition. In particular, VOCl ₃ where n = 0 is most preferably used.

Compounds in which 1 <n ≦ 3, for example, VO (OCH ₃ ) ₂ C
l, VO (OCH ₃ ) ₃ , VO (OC ₂ H ₅ ) ₂ Cl, VO (OC ₂ H ₅ ) ₃ , VO
(OC ₃ H ₇ ) ₂ Cl, VO (OC ₃ H ₇ ) ₃ , VO (OisoC ₃ H ₇ ) ₂ Cl, VO
Even when (OisoC ₃ H ₇ ) ₃ is used, the copolymerization itself in a system in which a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist can be carried out. However, the endothermic peak of the ethylene-1-butene copolymer obtained in this case by a differential thermal analyzer (DSC) is one in the range of 80 ° C. to 105 ° C. and 105 ° C.
In this case, two peaks, one in total, are observed in a region exceeding the above range, and such a copolymer may have reduced heat sealing performance or reduced transparency.

As an organoaluminum compound as a catalyst component,
Formula R _'m AlX _3-m (where, R' is a hydrocarbon group, X is halogen, 1 ≦ m ≦ 3 becomes a few shows.) Represented by, (C _{2
H 5) 2 AlCl, (C} 4 H 9) 2 AlCl, (C 6 H 13) 2 AlCl, (C 2 H 5)
_1.5 AlCl _1.5 , (C ₄ H ₉ ) _1.5 AlCl _1.5 , (C ₆ H ₁₃ ) _1.5 AlCl
_1.5 , C ₂ H ₅ AlCl ₂ , C ₄ H ₉ AlCl ₂ , C ₆ H ₁₃ AlCl _{2 and the} like.

A more preferable compound satisfies 1 ≦ m ≦ 2 in terms of a copolymerization reaction rate and a copolymer yield, and a particularly preferable compound is (C ₂ H ₅ ) _1.5 AlCl _1.5 .

As the halogenated ester compound as a catalyst component, a compound represented by the following general formula (Provided that R ″ is an organic group in which some or all of the hydrogen atoms of a hydrocarbon group having 1 to 20 carbon atoms are substituted with halogen;
R represents a hydrocarbon group having 1 to 20 carbon atoms. Is effective, preferably a compound in which all the substituents of R ″ are chloro-substituted, more preferably perchlorchlorotonate. Specifically, ethyl dichloroacetate, methyl trichloride Acetate, ethyl trichloroacetate, methyl dichlorophenyl acetate, ethyl dichlorophenyl acetate, methyl perchlorchlortonate, ethyl perchlorchlortonate, propyl perchlorchlortonate, isopropyl perchlorchlorotonate, butyl perchlorchlortonate, cyclopropyl Perchlorchlortonate, phenylperchlorcrotonate and the like can be exemplified.

The concentration of the vanadium compound in the copolymerization is 0.00005 mmol / to 5 mmol /, preferably 0.0001 mmol /.
And the ratio of the organoaluminum compound to the vanadium compound is 2.5 mol / mol.
In addition, the ratio between the halogenated ester compound and the vanadium compound must be 1.5 or more in molar ratio.

A more preferable ratio between the organoaluminum compound and the vanadium compound is 2.5 or more and 20 or less in molar ratio.

If the ratio of the organoaluminum compound and the vanadium compound is smaller than the specified range of the present invention, the copolymerization reaction becomes extremely unstable, a copolymer having a target structure cannot be obtained, and the copolymerization reaction is stopped. Or a copolymer having a wide molecular weight distribution is produced.

If the ratio between the halogenated ester compound and the vanadium compound is smaller than the range specified in the present invention, the molecular weight distribution of the produced copolymer is widened, which is not preferable in view of the object of the present invention.

The copolymerization in the present invention is performed in a hydrocarbon solvent. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as hexane, heptane, octane, decane, dodecane, and kerosene; cycloaliphatic hydrocarbons such as cyclohexane, methylcyclopentane, and methylcyclohexane; benzene, toluene, xylene, and the like. And aromatic hydrocarbons such as Particularly, hexane, heptane, octane and cyclohexane are preferred. Further, α-olefins such as propylene, 1-butene, 1-pentene, 1-hexene and the like can be used as a part or all of the solvent. The copolymerization temperature is preferably from 40 ° C to 80 ° C, particularly preferably from 40 ° C to 65 ° C.

When the copolymerization temperature is lower than the specified range of the present invention, the polymerization reaction rate is extremely reduced, and further, a special cooling and refrigeration equipment is required for removing the polymerization reaction heat, which is disadvantageous in industrial practice.

On the other hand, if the copolymerization temperature is higher than the specified range of the present invention,
In the copolymerization reaction system, all copolymers become soluble in the solvent, the viscosity of the copolymerization reaction system increases, the power required for stirring and mixing increases, and at higher temperatures, the polymerization activity of the catalyst is lost, A copolymer cannot be obtained.

The copolymer is carried out under atmospheric pressure or under pressure, and
It is preferably carried out at 30kg / cm ^2, especially between 1~20kg / cm ² preferably.

The average residence time of the copolymerization reaction solution in the copolymerization tank was 10
Minutes to 180 minutes, preferably 20 minutes to 120 minutes, and the total polymer concentration in the copolymer system is 15% by weight or less, preferably 12% by weight or less. Can get well.

The copolymerization is carried out under stirring with a system in which a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist.In particular, by controlling the molar ratio of ethylene and 1-butene to be supplied, at 40 ° C. Preferably, the copolymerization proceeds in a system having such a characteristic that the hydrocarbon solvent-insoluble polymer accounts for 95% by weight or more of the whole polymer and that at 70 ° C. the whole polymer becomes a hydrocarbon solvent-soluble polymer.

In such a copolymerization system, the copolymerization temperature is 40 ° C.
It is controlled at 65 ° C, particularly preferably at 40 ° C to 55 ° C. Here, because the copolymerization reaction proceeds in a state where the hydrocarbon solvent-insoluble polymer is suspended in fine particles having a particle size of 0.5 mm or less,
The viscosity of the copolymer system is low, the amount of stirring power energy is small, and it is also advantageous from the viewpoint of removing the heat of reaction.In addition, the mixing effect between the catalyst and the monomer is good, and the molecular weight distribution is narrow.
It is convenient to obtain a polymer having a uniform composition. on the other hand,
By controlling the temperature on the downstream side of the copolymerization tank to 70 ° C. or higher, all the polymers become soluble in the solvent. In the method of the present invention, the problems of industrial production such as sedimentation, deposition, or blockage of the conduit portion of precipitated polymer particles generally found in a slurry polymerization system in a flow failure part in a plant are controlled to a temperature of 70 ° C. or more. This can be easily solved.

In the present invention, the polymerization ratio of the hydrocarbon solvent-insoluble polymer and the hydrocarbon solvent-soluble polymer is determined by filtering the copolymer solution extracted from the polymerization vessel with a 300 mesh wire gauze, and mixing the hydrocarbon solvent-insoluble portion of the copolymer with the hydrocarbon solvent-insoluble portion. Separate the hydrogen solvent soluble part, remove the hydrocarbon solvent for each part and dry,
It is obtained by measuring the weight of the obtained solid copolymer.

The ethylene / 1-butene molar ratio in the ethylene / 1-butene copolymer according to the present invention is 88/12 to 98/2, and GPC (Gel Pe
The ratio of weight average molecular weight / number average molecular weight (hereinafter referred to as “Q value”) as determined by measurement (rmeation Chromatography) is 1.8.
~ 3.0. By satisfying these conditions, JIS K
An ethylene-1-butene copolymer having excellent properties at break strength, elongation, and surface hardness measured based on No. 6301 can be obtained.

Further, ethylene-1-butene copolymer having particularly excellent heat sealing performance and transparency has an ethylene / 1-butene content molar ratio of 92/8 to 96/4 and a Q value of 1.8 to 2.6, DS
This is an ethylene-1-butene copolymer in which only one endothermic peak due to C exists and the peak exists in the range of 80 ° C to 105 ° C.

The value of the number average molecular weight of the ethylene-1-butene copolymer of the present invention measured by GPC is from 35,000 to 80,000. If it is smaller than this range, the strength of the copolymer will be insufficient, and if it is larger than this range, the moldability will be poor.

 The GPC measurement conditions are as follows.

GPC: Waters 150C type column: Showa Denko KK Shodex AC-80M Sample amount: 300μ (polymer concentration 0.2wt%) Flow rate: 1ml / min Temperature: 135 ° C Solvent: 1,2,4- The trichlorobenzene calibration curve was prepared by a standard method using standard polystyrene manufactured by Toyo Soda Co., Ltd. For data processing, a data processor CP-8 model III manufactured by Toyo Soda Co., Ltd. was used.

For controlling the molecular weight of the ethylene-1-butene copolymer, H ₂ , diethylamine, aryl chloride pyridine-N-oxide and the like are used, but H ₂ is particularly preferable.

<Examples> Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

Example 1 Copolymerization of ethylene and 1-butene was continuously performed using a 5 SUS polymerization vessel equipped with stirring blades. That is,
Hexane is continuously supplied as a polymerization solvent at a rate of 5 / hour from the lower part of the polymerization vessel. On the other hand, the polymerization liquid is continuously withdrawn from the upper part of the polymerization vessel so that the polymerization liquid in the polymerization vessel always becomes 5. As a catalyst, vanadium oxytrichloride, ethyl aluminum sesquichloride, n-butyl perchlorcrotonate were each 0.005 mmol / hour,
It was continuously fed into the polymerization reactor from the lower part of the polymerization reactor at a rate of 1.2 mmol / hour and 0.12 mmol / hour. As monomers, ethylene and 1-butene were each 230 g / hour, 360 g
It was continuously fed from the lower part of the polymerization vessel into the polymerization vessel at a rate of g / hour. The molecular weight was adjusted with hydrogen. The copolymerization reaction was carried out at 55 ° C. by circulating cooling water through a jacket provided outside the polymerization vessel.

When a copolymerization reaction is carried out under the above-described conditions, an ethylene-1-butene copolymer is obtained in a state where a polymerization solvent-insoluble portion and a polymerization solvent-soluble portion coexist. A small amount of methanol was added to the polymerization solution withdrawn from the polymerization vessel to stop the polymerization reaction, and after removing the monomer and washing with water, the solvent was removed with steam in a large amount of water, and the copolymer was taken out. It dried under reduced pressure day and night. By the above operation, an ethylene-1-butene copolymer was obtained at a rate of 170 g / hour.

The ethylene content of the copolymer measured by infrared absorption spectrum analysis was 96.1 mol%, the number average molecular weight ( _N ) of the copolymer obtained by GPC measurement was 55,000, the weight average molecular weight ( _W ) was 112,000, and the Q value ( _W / _N ) = 2.2. The melting peak of the copolymer obtained by differential scanning calorimetry (DSC) was a single peak, showing a melting point (Tm) of 99 ° C. and a heat of fusion (ΔHm) of 19 cal / g.

On the other hand, the polymerization liquid extracted from the polymerization vessel was filtered through a 300 mesh wire mesh to separate the solvent-insoluble portion and the soluble portion of the copolymer, and the weight ratio of each portion was determined. Part = 61/39.

The copolymer obtained by press molding had very good transparency, a strength at break of 330 kgf / cm ² , an elongation at break of 710%, and a surface hardness of 93 (each conforming to JISK-6301).

Examples 2 to 5 The same procedures as in Example 1 were carried out except that the polymerization conditions were as shown in Table 1. The obtained copolymer was analyzed and evaluated in Example 1.
Table 2 summarizes the results.

Comparative Examples 1 and 2, without using perchlorcrotonic acid as a catalyst component,
Example 1 was repeated except that only vanadium oxytrichloride and ethylaluminum sesquichloride were used and the polymerization conditions were as shown in Table 1. The obtained copolymer was analyzed and evaluated in the same manner as in Example 1, and Table 2 summarizes the results.

Comparative Example 3 The same operation as in Example 1 was repeated except that the supply amount of ethylene was 100 g / hour and the supply amount of 1-butene was 500 g / hour. In the polymerization system, the whole copolymer became soluble in hexane and became a viscous solution. The recovered copolymer was rubbery, and the breaking strength was as low as 140 kg / cm ² .

Comparative Example 4 The same operation as in Example 1 was repeated except that the supply amount of ethylene was 300 g / hour, the supply amount of 1-butene was 300 g / hour, and the polymerization temperature was 25 ° C. The copolymer was mostly obtained as an insoluble polymer in the form of slurry suspended in hexane as fine particles, and some of the copolymer particles were deposited on the inner wall of the pipe after the outlet of the polymerization vessel.

The elongation at break of the recovered copolymer showed a low value of 420%.

Example 6 Using the same polymerization vessel as in Example 1, and equipment connected with a stirring blade, a jacket and 10 SUS pressure-resistant stirring tanks equipped with a vaporization component outlet (hereinafter referred to as "degasser"). Ethylene and 1-butene copolymerization was continuously performed. That is, hexane is continuously supplied as a polymerization solvent at a rate of 5 / hour from the lower part of the polymerization vessel. On the other hand, the polymerization liquid is continuously extracted from the upper part of the polymerization vessel so that the polymerization liquid in the polymerization vessel always becomes 5, introduced into the degasser, and further continuously extracted from the side surface of the degasser, The polymerization liquid in the degasser was controlled to always be 5.

Vanadium oxytrichloride, ethylaluminum sesquichloride, and dichlorophenylacetic acid were continuously supplied as catalysts from the lower part of the polymerization reactor into the polymerization reactor at a rate of 0.020 mmol / hr, 0.55 mmol / hr, and 0.060 mmol / hr, respectively. As monomers, ethylene and 1-butene were continuously fed into the polymerization reactor from the lower part of the polymerization reactor at a rate of 155 g / hour and 175 g / hour, respectively. The molecular weight was adjusted with hydrogen. The copolymerization reaction was carried out at 55 ° C by circulating cooling water through a jacket attached to the outside of the polymerization vessel.
I went in.

When the copolymerization reaction was carried out under the conditions as described above, an ethylene-1-butene copolymer was obtained in a state where the polymerization solvent-insoluble portion and the polymerization solvent-soluble portion coexisted. The polymerization liquid was continuously withdrawn from the polymerization vessel, introduced into a degasser, and a small amount of methanol was added to the polymerization liquid to stop the polymerization reaction. Controlled. The polymerization liquid extracted from the degasser has a particle size of 0.
The slurry had a state in which copolymer particles of about 01 to 0.1 mm were suspended. The polymerization solution was filtered through a 300 mesh wire mesh to separate the solvent-insoluble portion and the soluble portion of the copolymer, and the weight ratio of each portion was determined. The insoluble portion / soluble portion was 98/2. there were.

On the other hand, the ratio of insoluble portion / soluble portion in the copolymer in the polymerization liquid extracted from the polymerization vessel was 44/56.

Then, while continuing the polymerization, warm water was circulated through the jacket of the degasser to control the temperature inside the degasser to 70 ° C. No copolymer particles were found in the polymerization liquid discharged from the degasser, and the copolymer was in a state of being dissolved in the solvent hexane.

When the polymerization was further continued and the internal temperature of the degasser was cooled to 40 ° C., the polymerization liquid again took a slurry state in which the copolymer particles were suspended.

40 ° C with the copolymer sampled when the temperature inside the degasser is 70 ° C
The structural value with the copolymer collected at the point of the above agrees within the range of measurement error, the ethylene content of the copolymer measured by infrared absorption spectrum analysis is 94 mol%, and the copolymer weight obtained by GPC measurement is The number average molecular weight ( _N ) of the union was 49,000, the weight average molecular weight ( _W ) was 98,000, and the Q value ( _W / _N ) was 2.0.
Met. The melting peak of the copolymer obtained by differential scanning calorimetry (DSC) was a single peak, and the melting point (Tm) was 95 ° C.
It showed a heat of fusion (ΔHm) of 23 cal / g.

The transparency and mechanical properties of the copolymer were measured in the same manner as in Example 1.

Table 3 and Table 4 show the polymerization conditions and the physical properties of the copolymer.
It is summarized in the table.

Examples 7, 8 and Comparative Examples 5, 6 polymerization solvent, organoaluminum compound, halogenated ester compound, ethylene, the supply amount of 1-butene, or
The same operation as in Example 6 was performed except that the kind and amount of the vanadium compound were changed as described in Table 3.

 Table 4 shows the physical properties of the obtained copolymer.

Reference Examples 1 to 3 The copolymers obtained in Examples 6, 7, and 8 were added with 0.1% calcium stearate and octadecyl-3 as additives.
-(3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionate (Irgdnox 10 manufactured by Ciba-Geigy)
76) 0.2% and 0.05% of trisnonylphenyl phosphite (Antigene TNP manufactured by Sumitomo Chemical Co., Ltd.) were blended, granulated, and then formed into a 30 μm thick film. Table 5 shows the physical properties of these molded films.

Comparative Reference Examples 1 to 3 Table 5 shows the results of the same measurements as in Reference Examples 1 to 3 performed on the copolymers of Comparative Examples 5 and 6 and LLDPE (linear low-density polyethylene).

<Effects of the Invention> As described above, according to the present invention, in terms of equipment, energy, and cost, in copolymerization of a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer in a coexisting state, the molecular weight distribution Narrow, homogeneous ethylene-1-
A butene copolymer which is excellent in transparency and low-temperature heat sealing performance and has a small amount of solvent extraction components, and a method for producing the same can be provided.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the catalyst components and steps used in producing the ethylene-1-butene copolymer of the present invention.

Continuation of the front page (72) Inventor Minoru Takane 5-1 Anesaki Beach, Ichihara-shi, Chiba Sumitomo Chemical Co., Ltd. (56) References JP-A-63-17912 (JP, A) JP-A-63-20309 (JP) , A) JP-A-60-44509 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08F 210/02 C08F 4/68

Claims (7)

(57) [Claims] (1) ethylene and 1-butene;
The molar ratio of the / 1-butene content is 88/12 to 98/2, the value of the number average molecular weight measured by GPC is 35,000 to 80,000, and the ratio of weight average molecular weight / number average molecular weight is 1.8 to 3.0
An ethylene-1-butene copolymer. 2. An ethylene and 1-butene comprising ethylene
The molar ratio of the / 1-butene content is 92/8 to 96/4, the value of the number average molecular weight measured by GPC is 35,000 to 80,000, and the ratio of weight average molecular weight / number average molecular weight is 1.8 to 2.6
And only one endothermic peak by differential thermal analysis (DSC)
An ethylene-1-butene copolymer in which only a book exists and the peak exists in a range of 80 ° C to 105 ° C. (3) VO (OR) _n X _3-n (where R is a hydrocarbon group,
X represents a halogen, a number satisfying 0 ≦ n ≦ 3. An organoaluminum compound represented by the following formula: R ′ _m AlX _3-m (where R ′ represents a hydrocarbon group, X represents a halogen, and 1 ≦ m ≦ 3) (Provided that R ″ is an organic group in which some or all of the hydrogen atoms of a hydrocarbon group having 1 to 20 carbon atoms are substituted with halogen;
R represents a hydrocarbon group having 1 to 20 carbon atoms. Wherein the molar ratio of organoaluminum compound / vanadium compound is 2.5 or more, and the molar ratio of halogenated ester compound / vanadium compound is 1.
Using a catalyst system of 5 or more, the molar ratio of ethylene / 1-butene to be supplied was 35/65 to 60/40, and the copolymerization temperature was 40 ° C to 80 ° C.
3 ° C., wherein ethylene and 1-butene are copolymerized in a system in which a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist.
The method for producing the ethylene-1-butene copolymer described in the above. 4. VO (OR) _n X _3-n (where R is a hydrocarbon group,
X represents a halogen, a number satisfying 0 ≦ n ≦ 1. A) an organoaluminum compound represented by R ' _m AlX _3-m (where R' represents a hydrocarbon group, X represents a halogen, and 1 ≦ m ≦ 2). (Provided that R ″ is an organic group in which some or all of the hydrogen atoms of a hydrocarbon group having 1 to 20 carbon atoms are substituted with halogen;
R represents a hydrocarbon group having 1 to 20 carbon atoms. Wherein the molar ratio of the organoaluminum compound / vanadium compound is 2.5 to 30, and the molar ratio of the halogenated ester compound / vanadium compound is 1.
Using a catalyst system of 5 or more, the molar ratio of ethylene / 1-butene to be supplied was 40/60 to 58/42, and the copolymerization temperature was 40 ° C to 65 ° C.
° C., in a system where a hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist, ethylene and 1-butene are copolymerized, and the above-mentioned hydrocarbon solvent-insoluble polymer and a hydrocarbon solvent-soluble polymer coexist 2. The system according to claim 1, wherein the hydrocarbon solvent-insoluble polymer is at least 95% by weight of the total polymer at 40 ° C., and the total polymer is a hydrocarbon solvent-soluble polymer at 70 ° C. Or the method for producing an ethylene-1-butene copolymer according to claim 2. 5. The method according to claim 3, wherein the value of n in the general formula of the vanadium compound is 0. 6. The method according to claim 3, wherein the value of m in the general formula of the organoaluminum compound is 1.5. 7. The method according to claim 3, wherein the halogenated ester compound is perchlorcrotonate.