JPH0723410B2 - Ethylene random copolymer and method for producing the same - Google Patents

Description

The present invention relates to an ethylene-based random copolymer consisting essentially of repeating units derived from ethylene and repeating units derived from divinylbenzene, and a process for producing the same.

More specifically, the present invention is derived from ethylene-derived repeating units and divinylbenzene, which are excellent in melt tension and melt elasticity in melt molding such as blow molding, extrusion molding, and injection molding, and have less occurrence of drawdown and weld line. And an ethylene-based random copolymer essentially consisting of repeating units of

[Conventional technology]

Polyolefins such as polyethylene and polypropylene are lightweight, economical, and have excellent melt moldability, so they are easily molded by melt molding such as extrusion molding, blow molding, and injection molding, and are used for general purposes. There is. However, among these polyolefins, ethylene-based polymers containing ethylene as a main component, especially ethylene-based polymers polymerized by a Ziegler-type polymerization catalyst have excellent melt moldability, but especially in the field of blow molding. Has a drawback that melt tension and melt elasticity are insufficient and, as a result, a draw-down phenomenon easily occurs during molding and a weld line is generated in a molded product, and improvements thereof are strongly demanded. Conventionally, attempts have been proposed to improve such physical properties of polyolefin. For example, a method for achieving the object by improving the catalyst and its composition or polymerization formulation during the production of polyolefin, a method for achieving the same object by incorporating a modifier, or a method for partially modifying the polyolefin. Attempts have been made to achieve the same purpose by crosslinking with.

However, each method has a drawback that it is complicated and the degree of improvement is small. Therefore, in spite of the above proposals, there has been a demand for a polyolefin having excellent melt tension and melt elasticity.

On the other hand, a copolymer of α-olefin and a non-conjugated diene is also known.

JP-B-43-26865 discloses that α-olefin is polymerized by using a catalyst obtained by adding divinylbenzene to a system composed of titanium halide and bisdialkylaluminum.
-A method of polymerizing olefins is disclosed.

JP-B-44-4355 and JP-B-44-29260 disclose in which a catalyst obtained from a vanadium chelate compound and an organoaluminum compound is used to copolymerize ethylene and ethylene to introduce an unsaturated bond. A method for producing a substantially linear high molecular weight hydrocarbon polymer by copolymerizing an unsaturated hydrocarbon having two or more carbon-carbon double bonds is disclosed.

JP-A-47-34588 discloses an organic aluminum compound,
A non-conjugated diene comprising contacting one or more α-olefins with a non-conjugated diene in the liquid phase in the presence of a catalyst consisting of an organotitanium compound and optionally a halogen, a halogen-containing compound or mixtures thereof. A method of making a copolymer with a conjugated diene is disclosed. In the publication, divinylbenzene component is 22 mol% and
A copolymer of 90 mol% propylene and divinylbenzene is described.

JP-A-59-207905 discloses polymerizing diisopropenylbenzene and optionally other monomers in the presence of at least one α-olefin using alkyllithium as a catalyst in an amount of about 1 to 100 weight percent. Of diisopropenylbenzene and from 0 to about 99 weight percent of other monomers are disclosed.

However, none of the above-mentioned documents discloses an α-olefin random copolymer which is excellent in melt tension and melt elasticity in melt molding such as blow molding, extrusion molding, and injection molding, and has little occurrence of drag down and weld line. .

[Problems to be Solved by the Invention]

Therefore, the present invention is an ethylene-based random copolymer consisting essentially of repeating units derived from ethylene and repeating units derived from divinylbenzene, in blow molding, extrusion molding, melt molding such as injection molding. It is an object of the present invention to provide an ethylene-based random copolymer excellent in melt tension and melt elasticity and having little occurrence of drawdown, weld line and the like, and a method for producing the same.

[Means for solving problems]

According to the present invention, the above object is to provide an ethylene-based random copolymer comprising an ethylene component and a divinylbenzene component, wherein the repeating unit derived from (a) ethylene is 80 to 9:
9.99% by weight and the repeating unit derived from divinylbenzene are in the range of 0.01 to 20% by weight, and (b) the intrinsic viscosity [η] measured in decalin at 135 ° C.
Is in the range of 0.5 to 20 dl / g, (c) the molecular weight distribution (w / n) measured by gel permeation chromatography is 10 or less, and (d) is soluble in decalin at 135 ° C and insoluble. It is achieved by an ethylene-based random copolymer characterized by containing no gelled crosslinked polymer of.

Further, according to the present invention, the above object is the presence of a catalyst formed from (A) a highly active titanium catalyst component containing magnesium, tetravalent titanium and halogen as essential components, and (B) an organoaluminum compound catalyst component. By copolymerizing ethylene and divinylbenzene below, the repeating unit derived from ethylene is in the range of 80 to 99.99% by weight and the repeating unit derived from divinylbenzene is in the range of 0.01 to 20% by weight, and 135 ° C in decalin. Intrinsic viscosity [η] measured in the range of 0.5 to 20 dl / g, molecular weight distribution (Mw / Mn) measured by gel permeation chromatography of 10 or less, completely in decalin at 135 ℃ This is accomplished by a method for producing an ethylene-based random copolymer that does not contain a dissolved and insoluble gelled crosslinked polymer.

The present invention will be described in detail below.

The ethylene-based random copolymer of the present invention has most of the repeating units derived from ethylene represented by the formula —CH ₂ CH ₂ — and the divinylbenzene component. And is essentially composed of a repeating unit derived from divinylbenzene.

The divinylbenzene used in the present invention can be selected from the group consisting of o-divinylbenzene, m-divinylbenzene, p-divinylbenzene and mixtures thereof.
The divinylbenzene in the present invention may contain a small amount, for example, 10 mol% or less of other aromatic compounds such as ethylstyrene, diethylbenzene, dimethylethylbenzene and the like.

The ethylene used in the present invention is a small amount of other α-olefins such as propylene, 1-butene, 4-methyl-1.
-Can be replaced with a penten or the like.

In the ethylene random copolymer of the present invention, the repeating unit derived from ethylene is 80 to 99.99% by weight, preferably 90 to 99.99% by weight, more preferably 95 to 99.9% by weight, and the repeating unit derived from divinylbenzene. Is 0.01 to 20% by weight, preferably 0.05 to
It is 10% by weight, more preferably 0.1 to 1% by weight.

0.01% by weight of repeating units derived from divinylbenzene
When the amount is less, the effect of improving melt tension and melt elasticity during melt molding is small, and when the amount is more than 5% by weight, gel formation is observed in the molded product, which is not preferable because the physical properties of the molded product are adversely affected.

The intrinsic viscosity [η] of the ethylene copolymer of the present invention measured at 135 ° C. in decalin is 0.5 to 20 dl / g, preferably 0.5.
To 10 dl / g, more preferably 1 to 6 dl / g.

When the intrinsic viscosity [η] is less than 0.5, the surface quality of the molded product is deteriorated, which is not preferable. If it exceeds 20, the mechanical properties of the molded product deteriorate.

Molecular weight distribution of the ethylene random copolymer of the present invention measured by gel permeation chromatography (w /
n) is 10 or less, preferably 8 or less, more preferably 6
It is the following. When the molecular weight distribution (w / n) is larger than 15, gel formation occurs, which is not preferable.

The value of the molecular weight distribution (w / n) was measured by Takeuchi,
According to "Gel Permeation Chromatography" published by Maruzen, the procedure was as follows.

(1) Using a standard polystyrene of known molecular weight (Toyo Soda (manufactured by Toyo Soda Co., Ltd.) monodisperse polystyrene), the molecular weight M and its GPC (Gel Permeation Chromatograph) count are measured, and the correlation diagram between the molecular weight M and EV (Elution Volume) is calibrated. A curve was created. The concentration at this time was 0.02 wt%.

(2) A GPC chromatograph of the sample was taken by GPC measurement, and the polystyrene-equivalent number average molecular weight n and weight average molecular weight w were calculated according to the above (1) to obtain the w / n value. The sample preparation conditions and GPC measurement conditions in that case are as follows.

[Sample preparation]

(A) The sample was dispensed into an Erlenmeyer flask together with an o-dichlorobenzene solvent so as to have a concentration of 0.1 wt%.

(B) Anti-aging agent 2,6 in Erlenmeyer flask containing sample
-Di-tert-butyl-p-cresol was added at 0.05 wt% with respect to the polymer solution.

(C) The Erlenmeyer flask was heated to 140 ° C. and stirred for about 30 minutes to dissolve it.

(D) The liquid was applied to GPC.

[GPC measurement conditions] The measurement was carried out under the following conditions.

(B) Volume Waters (150C-ALC / GPC) (b) Column Toyo Soda (GMH type) (c) Sample volume 400μ (d) Temperature 140 ° C (e) Flow rate 1ml / min The random copolymer is soluble in decalin at 135 ° C and contains no insoluble gel-like crosslinked polymer.

The ethylene-based random copolymer of the present invention has the characteristics described above, but preferably has the following characteristics.

Melt tension (T) of the ethylene-based random copolymer of the present invention
The ratio (T / To) of ethylene homopolymer not containing divinylbenzene and having the same intrinsic viscosity [η] and molecular weight distribution to the melt tension (To) is 1.1 to 5, preferably 1.1 to 4. It is preferably in the range of 1.2 to 3. If the above ratio (T / To) is larger than 5, gel is likely to be formed and the surface quality of the molded product is deteriorated.
If it is smaller, the effect of improving the drawdown property and also the effect of improving the weld line are reduced.

The crystallinity of the ethylene random copolymer of the present invention by X-ray diffractometry is 30% to 80%, preferably 40% to 80%.
%, More preferably 40% to 70%.

In the ethylene random copolymer of the present invention, the soluble amount [W ₂ % by weight] in an acetone / n-decane mixed solvent (volume ratio 1/1) at 10 ° C is based on the weight of the copolymer. 4 × [η] ^-1.2 % by weight or less, preferably 0.1 ×
[Η] ^{−1.2 to} 3.5 × [η] wt%, particularly preferably 0.
It is in the range of 3 × [η] ^{−1.2 to} 3 × [η] ^−1.2 (where [η] is the numerical value of the intrinsic viscosity of the copolymer, which is the value excluding the dimension). This characteristic value is a scale showing the content of the low molecular weight polymer component in the ethylene random copolymer of the present invention and showing the composition distribution and the range of the molecular weight of the copolymer. The conventionally known ethylene-based random copolymer contains a large amount of the acetone / n-decane mixed solvent-soluble component, is inferior in surface non-adhesiveness, and is a major cause of blocking property. This property value in the ethylene-based random copolymer of the present invention, together with other property values, serves to give the above-mentioned excellent properties to the copolymer. In the present invention, the soluble content of the copolymer in the mixed solvent is measured and determined by the following method. That is, in a 150 ml flask equipped with a stirring blade, 1 g of the copolymer sample, 0.05 g of 2,6-ditert-butyl-4-methylphenol and 50 ml of n-decane were put and dissolved in an oil bath at 120 ° C. Let Allow to cool naturally at room temperature for 30 minutes after dissolution, then 50 ml
Of acetone is added in 30 seconds and cooled on a water bath at 10 ° C. for 60 minutes. The solution in which the precipitated copolymer and the low molecular weight polymer component were dissolved was over-separated with a glass filter and the solution was adjusted to 10 mmHg.
Dry at 150 ℃ until constant weight, weigh it,
The soluble content of the copolymer in the mixed solvent was calculated and determined as a percentage with respect to the weight of the sample copolymer. In the above-mentioned measuring method, stirring was continuously performed from the time of dissolution to immediately before the stirring.

The ethylene random copolymer of the present invention is excellent in melt tension (melt tension) and melt elasticity particularly in melt molding such as blow molding, extrusion molding, and injection molding, and hardly causes drawdown and weld line.

The ethylene-based random copolymer of the present invention having the characteristics described above is (A) a highly active titanium catalyst component containing magnesium, tetravalent titanium, halogen and, if necessary, an electron donor as an essential component, It can be produced by copolymerizing ethylene and divinylbenzene in the presence of a catalyst formed from (B) an organoaluminum compound catalyst component, and optionally (C) an electron donor.

Highly active solid titanium catalyst component (A) used in the present invention
Contains magnesium, tetravalent titanium, halogen and, if necessary, an electron donor as an essential component, and has a magnesium / titanium (atomic ratio) of more than 1, preferably 3 to 50, particularly preferably 6 to 30. , Halogen / titanium (atomic ratio) is preferably 4 to 100, particularly preferably 6 to 40, and when an electron donor component is used, electron donor / titanium (molar ratio) is preferably 0.1 to 10, particularly preferably. It is in the range of 0.2 to 6. Its specific surface area is preferably 3 m ² / g or more, more preferably about 40 m ² / g or more, more preferably 100 m ² / g to 800 m ² / g.
Is. Usually, titanium compounds are not eliminated by simple means such as hexane washing at room temperature. The X-ray spectrum shows a microcrystallized state with respect to the magnesium compound regardless of the raw material magnesium compound used for the catalyst preparation, or it is desirable that the X-ray spectrum is much higher than that of a usual commercial product of magnesium dihalide. It is in a microcrystallized state. Further, in addition to the above essential components, other elements, metals, functional groups, etc. may be contained. Further, it may be diluted with an organic or inorganic diluent.

The solid titanium catalyst component (A) has an average particle size of 1 to 20.
0 μ, preferably 3 to 100 μ, particularly preferably 6 to 50 μ and having a geometric standard deviation of the particle size distribution of less than 2.1,
It is preferably 1.9 or less, more preferably 1.7 or less.

Here, the particle size distribution of the titanium catalyst component particles can be measured by a light transmission method. Concretely, the catalyst component is diluted to a concentration of around 0.01 to 0.5% in an inert solvent such as decalin, put in a measuring cell, shining light on the cell, and passing the liquid in a sedimented state with particles. The particle size distribution is measured by continuously measuring the light intensity. The standard deviation σg is obtained from the lognormal distribution function based on this particle size distribution. The average particle diameter of the catalyst is shown by the weight average particle diameter, and the particle size distribution is measured by sieving in the range of 10 to 20% of the weight average particle diameter.

The solid titanium catalyst component (A) is preferably pearl-shaped,
It has a spherical shape such as an elliptical shape or a granular shape.

By using a titanium catalyst component satisfying these requirements, a copolymer having a high ethylene content can be produced with good operability and in a high yield.

The titanium catalyst component (A) satisfying all the above conditions is prepared by forming a magnesium compound having an average particle size and particle size distribution, more preferably a shape in the above range, and then preparing the catalyst. It can be obtained by a method of performing, or a method of bringing a liquid magnesium compound and a liquid titanium compound into contact with each other to form a solid catalyst having the above-mentioned particle properties. Such methods are described in, for example, JP-A-55-135102, JP-A-55-135103, and JP-A-55-135103.
No. 56-811, No. 56-67311, and Japanese Patent Application No. 56-181019.

A few examples of these methods are briefly described.

(1) A magnesium compound / electron donor complex having an average particle size of 1 to 200μ and a geometric standard deviation σg of particle size distribution of less than 2.1 is used, if necessary, in an electron donor and / or an organoaluminum compound or a halogen-containing silicon compound. Pretreatment with such a reaction aid or without pretreatment is carried out with a titanium halide compound which forms a liquid phase under the reaction conditions, preferably titanium tetrachloride.

(2) A liquid compound of a magnesium compound having no reducing ability is reacted with a liquid titanium compound in the presence of an electron donor, if necessary, so that the average particle size is 1 to 200 μ and the geometric standard deviation σg of the particle size distribution is Precipitate solid components less than 2.1. If necessary, a liquid titanium compound, preferably titanium tetrachloride, or it is reacted with an electron donor.

Particularly, in the present invention, in the case of using the magnesium compound or the electron donor complex precipitated from the liquid as a spherical solid in the method of (1), or (2)
Good results are obtained when the precipitation of the solid component by the method described in (1) is carried out under the condition that a spherical solid is precipitated.

As the magnesium compound used for the preparation of the titanium catalyst component, magnesium oxide, magnesium hydroxide, hydrotalcite, magnesium carboxylate, alkoxy magnesium, allyloxy magnesium, alkoxy magnesium halide, allyloxy magnesium halide, magnesium dihalide, Examples thereof include organomagnesium compounds, reaction products of organomagnesium compounds with electron donors, halosilanes, alkoxysilanes, silanols, aluminum compounds and the like. The organoaluminum compound that may be used in the preparation of the titanium catalyst component may be selected from the organoaluminum compounds that can be used in the olefin polymerization described below. Furthermore, examples of the halogen-containing silicon compound that may be used for the preparation of the titanium catalyst component include tetrahalogenated silicon, alkoxyhalogenated silicon, alkylhalogenated silicon, and halopolysiloxane.

Examples of titanium compounds used for preparing the titanium catalyst component include titanium tetrahalides, alkoxy titanium halides, allyloxy titanium halides, alkoxy titanium,
Examples thereof include allyloxy titanium, and titanium tetrahalide is preferable, and titanium tetrachloride is particularly preferable.

Examples of electron donors that may be optionally used in the preparation of the titanium catalyst component include alcohols, phenols,
Oxygen-containing electron donors such as ketones, aldehydes, carboxylic acids, esters of organic or inorganic acids, ethers, acid amides, alkoxysilanes of acid anhydrides, ammonia, amines,
Nitrogen-containing electron donors such as nitrile and isocyanate can be used.

More specifically, it has 1 to 18 carbon atoms such as methanol, ethanol, propanol, pentanol, hexanol, octanol, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol and isopropylbenzyl alcohol.
Alcohols of 6 to 20 carbon atoms which may have a lower alkyl group such as phenol, cresol, xylenol, ethylphenol, propylphenol, nonylphenol, cumylphenol and naphthol; acetone, methylethylketone, methylisobutylketone C3 to C15 ketones such as acetophenone and benzophenone; acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde,
Aldehydes having 2 to 15 carbon atoms such as tolualdehyde and naphthaldehyde; methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, ethyl propionate, methyl butyrate, ethyl valerate, chloroacetic acid. Methyl, ethyl dichloroacetate,
Methyl methacrylate, ethyl crotonate, cyclohexanecarboxylate, ethyl benzoate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, phenyl benzoate, benzyl benzoate, toluyl Methyl acid,
Ethyl toluate, amyl toluate, ethyl ethyl benzoate, methyl anisate, ethyl anisate, ethyl ethoxybenzoate, dibutyl malonate, isopropyl malonate diethyl, diethyl n-butylmalonate, diethyl phenylmalonate, 2-allylmalonate Diethyl acid, di iso
Diethyl butyl malonate, Di-n-butyl diethyl malonate, Di-n-butyl succinate, Diethyl methyl succinate, Dibutyl ethyl succinate, Dimethyl maleate, Dibutyl maleate, Monooctyl maleate, Dioctyl maleate, Dibutyl butyl maleate, Butyl maleate Diethyl acid, diisooctyl fumarate, diethyl itaconic acid, di-n-butyl itaconic acid, dimethyl citraconic acid, 1,
Diethyl 2-cyclohexanedicarboxylate, di2-ethylhexyl 1,2-cyclohexanedicarboxylate, dimethyl phthalate, monoisobutyl phthalate, diethyl phthalate, ethyl n-butyl phthalate, di-n-propyl phthalate,
N-Butyl phthalate, isobutyl phthalate, din-heptyl phthalate, di2-ethylhexyl phthalate, di-n-octyl phthalate, dineopentyl phthalate, benzyl butyl phthalate, diphenyl phthalate, iso-butyl naphthalenedicarboxylate, Di2-ethylhexyl sebacate,
γ-butyrolactone, δ-valerolactone, coumarin,
C2 to C30 organic esters such as phthalide and ethylene carbonate; acetyl chloride, benzoyl chloride,
2 carbon atoms such as toluyl chloride and anisyl chloride
To 15 acid halides; ethers having 2 to 20 carbon atoms such as methyl-ether, ethyl ether, isopropyl ether, butyl ether, isoamyl ether, tetrahydrofuran, anisole, diphenyl ether; acetic acid amide, benzoic acid amide, toluic acid amide Acid amides such as; amines such as methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline, tetramethylmethylenediamine, tetramethylethylenediamine; nitriles such as acetonitrile, benzonitrile, tolunitrile Kinds; Organophosphorus compounds having a P--O--C bond such as trimethyl phosphite and triethyl phosphite; Alkoxysilanes such as ethyl silicate and diphenyldimethoxysilane And the like.
Two or more kinds of these electron donors can be used.

The electron donors that are preferably contained in the titanium catalyst component (A) include organic acid or inorganic acid esters, alkoxy (aryloxy) silane compounds, ethers, ketones, tertiary amines, acid halides, acid anhydrides. Organic acid esters and alkoxy (aryloxy) silane compounds are particularly preferable because they do not have active hydrogen, and among these, esters of aromatic monocarboxylic acids and alcohols having 1 to 8 carbon atoms, malonic acid, substituted malonic acid, substituted amber. Esters of dicarboxylic acids such as acid, maleic acid, substituted maleic acid, 1,2-cyclohexanedicarboxylic acid and phthalic acid with alcohols having 2 or more carbon atoms are particularly preferable. Of course, these electron donors do not necessarily have to be used as raw materials when preparing the titanium catalyst, and may be used as other compounds that can be converted into these electron donors and converted into these electron donors during the catalyst preparation process.

After completion of the reaction, the titanium catalyst component obtained by the various methods as exemplified above can be purified by thoroughly washing with a liquid inert hydrocarbon. As the inert liquid hydrocarbon used for this purpose, n-pentane, isopentane, n-pentane,
Hexane, isohexane, n-heptane, n-octane, isooctane, n-decane, n-dodecane, kerosene,
Aliphatic hydrocarbons such as liquid paraffin; Alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane; Aromatic hydrocarbons such as benzene, toluene, xylene, cymene; Chlorobenzene, dichloroethane Such halogenated hydrocarbons or mixtures thereof can be exemplified.

The high activity titanium catalyst component (A) used in the method of the present invention may be a high activity titanium catalyst component prepared by the above method, and if necessary, the high activity titanium catalyst component may be an organic compound. It is also possible to use a highly active titanium catalyst component treated with an aluminum compound and an electron donor. As the method of this contact treatment, a method of bringing the organoaluminum compound and the electron donor into contact with the highly active titanium catalyst component in the hydrocarbon medium at a temperature of −20 to 150 ° C. with stirring can be adopted. . As the electron donor, the compounds exemplified above can be similarly exemplified, and as the organoaluminum compound, the compounds exemplified as the organoaluminum compound catalyst component (B) described later can be similarly exemplified. Among these highly active titanium catalyst components (A), it is preferable to use an organoaluminum compound and a highly active titanium catalyst component contact-treated with an electron donor because an ethylene-based random copolymer having a narrow molecular weight distribution can be obtained.

The preferred organometallic compound catalyst component (B) used in the present invention is an organoaluminum compound, and a compound having at least one Al-carbon bond in the molecule can be used. For example, (i) the general formula R ¹ _m Al (OR ² ) nHpXq (wherein R ¹ and R ² are hydrocarbon groups usually containing 1 to 15, preferably 1 to 4 carbon atoms, which may be the same or different. Halogen, m is 0 <m ≦ 3, n is 0 ≦
n <3, p is 0 ≦ p <3, q is a number 0 ≦ q <3, and m + n + p + q = 3), and (ii) the general formula M ¹ A ▲ l ¹ ₄ ▼ (wherein M ¹ is Li, Na, K, and R ¹ is the same as above), and a complex alkyl compound of a Group 1 metal and aluminum.

Examples of the organoaluminum compound belonging to (i) above include the following. General formula ▲ R ¹ _m ▼ Al (OR ² )
_3- m (wherein R ¹ and R ² are the same as above. M is preferably
1.5 ≦ m ≦ 3). General formula ▲ R ¹ _m ▼ AlX _3- m (wherein R ¹ is the same as above. X is halogen, and m is preferably 0).
<M <3), the general formula ▲ R ¹ _m ▼ AlH _3- m (where R ¹ is the same as above, m is preferably 2 ≦ m ≦ 3), the general formula ▲ R ¹ _m ▼ Al (OR ² ) nXq (where R ¹ and R ² are the same as before. X is halogen, 0 <m ≦ 3, 0 ≦ n <3, 0 ≦ q <
3 and m + n + q = 3).

In the aluminum compound belonging to (i), more specifically, trialkyl aluminum such as triethyl aluminum and tributyl aluminum, trialkenyl aluminum such as triisoprenyl aluminum, diethyl aluminum ethoxide, dialkyl aluminum alkoxide such as dibutyl aluminum butoxide, In addition to alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide, ▲ R ¹ _2.5 ▼ Al (OR ² ) _0.5
Partially alkoxylated alkylaluminum having an average composition represented by, for example, diethylaluminium chloride, dibutylaluminium chloride, dialkylaluminum halides such as diethylaluminium bromide, ethylaluminum sesquichloride, butylaluminum sesquichloride, ethylaluminum sesquibromide. Partially halogenated alkyl aluminum such as alkyl telminium sesquihalide, stirred chilled aluminum dichloride, propyl aluminum dichloride, butyl aluminum dihalide, etc. alkyl aluminum dihalide, diethyl aluminum hydride, dibutyl aluminum hydride etc. Dialkyl aluminum hydride, ethyl aluminum dihydride, pro Le aluminum alkyl aluminum partially hydrogenated alkylaluminum such as dihydride such as dihydride, ethyl aluminum ethoxy chloride, butyl aluminum butoxide cycloalkyl chloride,
It is a partially alkoxylated and halogenated alkyl aluminum such as ethyl aluminum ethoxy bromide. Further, the compound similar to (i) may be an organoaluminum compound in which two or more aluminums are bound via an oxygen atom or a nitrogen atom. Examples of such compounds include (C ₂ H ₅ ) ₂ AlOAl (C ₂ H ₅ ) ₂ and (C ₄ H ₉ ).
₂ AlOAl (C ₄ H ₉ ) ₂ , Can be exemplified. Examples of the compound belonging to (ii) above include LiAl (C ₂ H ₅ ) ₄ and LiAl (C ₇ H ₁₅ ) ₄ . Among these, it is particularly preferable to use trialkylaluminum or a mixture of trialkylaluminum and alkylaluminum halide or aluminum halide.

In the method of the present invention, the copolymerization reaction can be carried out in the presence of a catalyst composed of the highly active titanium catalyst component (A) and the organoaluminum compound catalyst component (B), and further the electron donor component (C). It is preferable to carry out the copolymerization in the presence of a catalyst formed from, because an ethylene-based random copolymer having a narrow molecular weight distribution can be obtained. Examples of the electron donor used as the catalyst component (C) are amines, amides, ethers, ketones, nitriles, phosphines, stibines, arsines, phosphoramides, esters, thioethers, thioesters. And acid anhydrides, acid halides, aldehydes, alcoholates, alkoxy (aryloxy) silanes, organic acids, and amides and salts of metals belonging to Groups 1 to 4 of the periodic table. . Salts can also be formed in situ by the reaction of an organic acid with an organometallic compound used as catalyst component (B).

Specific examples thereof include titanium catalyst component (A)
The electron donor contained in the above can be selected from those exemplified above. Good results are obtained with organic acid esters, alkoxy (aryloxy) silane compounds, ethers, ketones, acid anhydrides, amines and the like. Particularly when the electron donor in the titanium catalyst component (A) is a monocarboxylic acid ester, the electron donor as the component (C) is preferably an alkyl ester of an aromatic carboxylic acid.

Further, when the electron donor in the titanium catalyst component (A) is an ester of a dicarboxylic acid and an alcohol having 2 or more carbon atoms as exemplified above as preferable ones, the general formula RnSi
(OR ¹ ) _4- n (wherein R and R ¹ are hydrocarbon groups, 0 ≦ n <4)
It is preferable to use an alkoxy (aryloxy) silane compound represented by and an amine having a large steric hindrance as the component (C). Specific examples of the alkoxy (aryloxy) silane compound include trimethylmethoxysilane,
Trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane , Γ-chloropropyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, vinyltriethoxysilane, butyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriethoxysilane Isopropoxysilane, vinyltributoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltriallyloxy (allylo
xy) silane, vinyltris (β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydicycloxane, etc., among which methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethylethoxysilane, Vinyltriethoxysilane, phenyltriethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyl silicate and the like are preferable.

Further, as the amine having a large steric hindrance, 2,2,6-tetramethylpiperidine, 2,2,5,5-tetramethylpyrrolidine, derivatives thereof, tetramethylmethylenediamine and the like are particularly preferable.

The ratio of the amount of ethylene and the amount of divinylbenzene to be copolymerized in the method for producing an ethylene-based random copolymer of the present invention is such that ethylene is 80 to 99.99% by weight, preferably 90 to 99.9% by weight, and more preferably 95 to 99.5% by weight. %, And divinylbenzene is 0.1 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.

In the production of the ethylene-based random copolymer of the present invention, 30 g / g of the titanium catalyst component (A) of the catalyst is used.
00g or more, preferably 5000g or more, more preferably 7000g
The above ethylene and divinylbenzene are copolymerized.

The copolymerization reaction is carried out in an inert solvent or without solvent.

When an inert solvent is used in the copolymerization, the titanium catalyst component (A) is preferably 0.001 to 500 mmol, more preferably 0.005 to 200 mmol, in terms of titanium atom, per one inert solvent. The compound (B) has an Al / Ti (atomic ratio) of 0.1 to 1000, especially 0.
It is preferable to use it in such a ratio as to be 5 to 500. The catalyst component (C) may be supported on the component (A), may be added to a part of the component (B) and used, or may be added to the polymerization system in a free state. In any case, the catalyst component (C) is 0.1 to 200 per mol of titanium atom.
It may be present in a molar amount, particularly about 0.2 to 50 mol.

As the inert hydrocarbon solvent used for the copolymerization, propane, butane, n-pentane, iso-pentane, n-hexane, isohexane, n-heptane, n-octane,
Aliphatic hydrocarbons such as isooctane, n-decane, n-dodecane and kerosene, alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane and methylcyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene. , Methylene chloride, ethyl chloride,
Examples thereof include halogenated hydrocarbons such as ethylene chloride and chlorobenzene. Among them, aliphatic hydrocarbons, particularly aliphatic hydrocarbons having 4 to 10 carbon atoms are preferable.

The copolymerization temperature can be appropriately selected and is preferably about 20 to about
The temperature is 200 ° C., more preferably about 50 to about 180 ° C., the pressure can be appropriately selected, and the pressure is from atmospheric pressure to about 100 kg / cm ² , preferably about 2 to about 50 kg / cm ^2. preferable.

The molecular weight can be adjusted to some extent by changing the polymerization conditions such as the polymerization temperature and the proportion of the catalyst component used.
It is most effective to add hydrogen into the polymerization system.

The ethylene random copolymer of the present invention is suitable for molded articles such as tubes, bottles and tanks.

Example 1 [Synthesis of Ti catalyst component] 5 g of commercially available anhydrous magnesium chloride was suspended in 200 ml of n-decane, and 14.5 g of ethanol was added dropwise with stirring over 1 hour, followed by stirring for 1 hour. Next, 15.8 g of diethylaluminum chloride was added dropwise at room temperature, and the mixture was stirred at 40 ° C for 1 hour. After adding 100 ml of titanium tetrachloride to the system, the temperature was raised and the mixture was stirred at 80 ° C. for 2 hours. The supernatant was washed with fresh n-decane by decantation to obtain a Ti-containing catalyst component. The Ti catalyst component is titanium 5.2% by weight, chlorine 64% by weight, magnesium 16% by weight, aluminum 2.1% by weight, ethoxy group 9.7.
Including wt%. The specific surface area was 65 m ² / g.

〔polymerization〕

Hexane 1 and 2 ml of divinylbenzene are added to an autoclave having an internal volume of 2. The system is heated to 60 ° C., and 2 mmol of triisobutylaluminum and 0.02 mg atom of the above Ti catalyst component in terms of Ti atom are added. Hydrogen at partial pressure
After adding ² kg / cm ² , polymerization was carried out once at a polymerization temperature of 80 ° C. while feeding ethylene so that the total pressure was 8 kg / cm ² . The yield of the obtained polymer was 322 g, the apparent specific gravity was 0.33 g / cc,
[Η] is 2.65dl / g, melt tension is 17g, T / T
The value was 2.2. Further, no gel product was observed in the polymer, and the amount of acetone.n-decane-soluble component at 10 ° C was 0.1% by weight. The w / n by GPC was 5.3, the divinylbenzene content in the copolymer was 0.07% by weight, and the crystallinity by XRD was 70.5%.

Comparative Example 1 [Polymerization] Polymerization was carried out in the same manner as in Example 1 except that the Ti catalyst component of Example 1 was used and 2 ml of divinylbenzene was not added.

Polymer yield is 360 g, apparent specific gravity is 0.33 g / cc, and [η] is 2.
It was 50 dl and the melt tension was 9 g.

Example 2 [Synthesis of titanium catalyst component] Decane solution 83.6 containing 50 mmol of ethylbutyl magnesium
ml and 2-ethylbexyl alcohol 23.1 ml (15 mmol) are heated at 80 ° C. for 2 hours to form a homogeneous solution, and 1.4 ml of ethyl benzoate is added to this solution to give a sufficient homogeneous solution. It is added dropwise to 200 ml of titanium tetrachloride kept at 20 ° C under stirring for 1 hour. After the dropwise addition was completed, the mixture was heated to 90 ° C. over 1 hour and 30 minutes, 1.8 ml of ethyl benzoate was added, and the mixture was kept under stirring at 90 ° C. for 2 hours, and then the solid portion was collected by filtration. , Resuspend it in 200 ml of titanium tetrachloride, heat at 90 ° C for 2 hours, collect the solid substance by filtration, and purify with hexane until no free titanium compound is detected in the washing solution. After that, the titanium catalyst component is obtained by sufficiently washing and drying. The component is 2.8% by weight of titanium, 61% by weight of chlorine and 20% of magnesium in terms of atoms.
% By weight and 13.8% by weight of ethyl benzoate, and the catalyst component has an average particle size of 13 μ and a geometric standard deviation (σ
g) was a granular catalyst with 1.4. Specific surface area is 180
It was m ² / g.

〔polymerization〕

A system in which hexane 1 and 20 ml of divinylbenzene are added to an autoclave having an internal volume of 2 is heated, and at 60 ° C., 2 mmol of triethylaluminum and 0.02 mg atom of the above Ti catalyst component in terms of Ti atom are added. Hydrogen partial pressure 4 kg / cm
After adding ^2, while supplying so that an ethylene total pressure 8 kg / cm ^2, the 1 hour of polymerization at a polymerization temperature 80 ° C. KoTsuta. The polymer yield was 150 g, the apparent specific gravity of the polymer was 0.36 g / cc, and [η] was 3.
50dl / g, melt tension 31g, T / To value 1.9, w /
n was 4.8. No gel product was found in the copolymer. The amount of the acetone-m-decane-soluble component at 10 ° C was 0.1% by weight, and the divinylbenzene content of the copolymer was 0.14% by weight. Crystallinity by X-ray
It was 68%.

Example 3 [Synthesis of Ti catalyst component] In a nitrogen stream, 1 mol of commercially available metal magnesium was added to 500 ml of dehydrated and purified hexane, 1.1 mol of tetraethoxysilane was further added, and the temperature was raised to 65 ° C with stirring. After raising the temperature,
A small amount of methyl iodide and iodine were added dropwise, and then 1.2 mol of n-butyl chloride was added dropwise over 2 hours, followed by stirring at 70 ° C. for 3 hours. After completion of the reaction, collect the solid part by filtration,
The solid portion was repeatedly washed with hexane. After suspending 10 g of the solid in 100 ml of titanium tetrachloride and stirring at 130 ° C. for 2 hours,
The supernatant was removed by decantation, 100 ml of titanium tetrachloride was further added, and the mixture was stirred at 130 ° C for 1 hour. The produced solid part was collected by heating, and the solid part was sufficiently washed with hot n-decane and room temperature decane. The generated solid is titanium 6.3
% By weight, 64.0% by weight chlorine, 19.0% by weight magnesium, 3.6% by weight ethoxy group.

The average particle size of the produced solid was 10 µ, and the granular catalyst had a geometric standard deviation (σg) of 1.7 and was a granular catalyst. The specific surface area was 206 m ² / g.

〔polymerization〕

Hexane 1 was added to an autoclave with an internal volume of 2 and the system was heated to 2 mmol of triethylaluminum at 60 ° C.
And 0.02 mg atom of the above Ti catalyst component is added in terms of Ti atom.

After adding hydrogen at a partial pressure of 2.3 kg / cm ^2, add ethylene at a total pressure of 8 kg / c.
Polymerization was carried out at a polymerization temperature of 80 ° C. for 1 hour while supplying m ² to the mixture. After 1 hour, depressurize and divinylbenzene 3m in the system.
After adding l, ethylene partial pressure 3.0 kg / cm ² , butene-
Polymerization was carried out at 80 ° C. for 1 hour while maintaining a partial pressure of 0.5 kg / cm ² .

The yield of the obtained copolymer was 338 g, and the apparent specific gravity was 0.38.
The g / cc and [η] were 2.60 dl / g, w / n was 9.0, the melt tension was 19 g, and the T / To value was 2.1. No gel product was observed, and the amount of acetone / m-decane soluble part was
It was 0.2%. The divinylbenzene content of the copolymer was 0.06% by weight. The crystallinity by X-ray was 69.5%. According to the analysis of the polymer after the completion of the first stage polymerization, the yield was 162 g, [η] was 0.89 dl / g, and w / n was 5.5.
It was.

〔The invention's effect〕

According to the present invention, an ethylene-based random copolymer comprising a repeating unit derived from ethylene and a repeating unit derived from divinylbenzene, which has melt tension and melt elasticity in melt molding such as blow molding, extrusion molding and injection molding. It is possible to obtain an ethylene dam copolymer and a method for producing the same, which is excellent in the production of a drawdown and a weld line.

[Brief description of drawings]

FIG. 1 is a flow chart showing the steps for preparing the catalyst according to the present invention.

Claims (2)

[Claims] 1. An ethylene-based random copolymer comprising an ethylene component and a divinylbenzene component, wherein the repeating unit derived from (a) ethylene is 80 to 9:
9.99% by weight and the repeating unit derived from divinylbenzene are in the range of 0.01 to 20% by weight, and (b) the intrinsic viscosity [η] measured in decalin at 135 ° C.
Is in the range of 0.5 to 20 dl / g, (c) the molecular weight distribution (w / n) measured by gel permeation chromatography is 10 or less, and (d) is soluble in decalin at 135 ° C and insoluble. An ethylene-based random copolymer characterized by not containing the gelled cross-linked polymer of. 2. Ethylene in the presence of a catalyst formed from (A) a highly active titanium catalyst component containing magnesium, tetravalent titanium and halogen as essential components, and (B) an organoaluminum compound catalyst component. By copolymerizing and divinylbenzene, the repeating unit derived from ethylene is in the range of 80 to 99.99% by weight and the repeating unit derived from divinylbenzene is in the range of 0.01 to 20% by weight, and the limit measured in decalin at 135 ° C. The viscosity [η] is in the range of 0.5 to 20 dl / g, the molecular weight distribution (w / n) measured by gel permeation chromatography is 10 or less, and it is completely insoluble in decalin at 135 ° C. 1. A method for producing an ethylene-based random copolymer containing no gelled crosslinked polymer.