JPS6339902A - Production of ultrahigh-molecular weight polyethylene - Google Patents

Abstract

PURPOSE:To produce the title PE in a high catalytic activity and good productivity, by contacting ethylene or a gaseaus mixture of ethylene and an alpha-olefin with a specified catalyst. CONSTITUTION:A catalyst is obtained by contacting a prepolymerization product (A) obtained by prepolymerizing 5-50 g of a 3C or higher alpha-olefin on a 1g of a Ziegler catalyst component containing Ti, Mg and a halogen as essential components at 0-80 deg.C with an organoaluminum compound (B) of formula I or II (wherein R<2-3> are each a 1-20C hydrocarbon residue or H, R<4> is a 1-20C hydrocarbon residue, X is a halogen, 0 <= n and m <= 3) and a compound (C) having an Si-O-C, B-O-C or P-O-C bond [e.g., Si(OCH3)4]. Ethylene or a gaseous mixture of ethylene and an alpha-olefin is contacted with said catalyst at room temperature to 100 deg.C to obtain an ultrahigh MW PE of a weight-average MW of 500,000-3,000,000.

Description

DETAILED DESCRIPTION OF THE INVENTION [Background of the Invention] The present invention relates to ultra-high molecular weight polyethylene having a weight average molecular weight m of 500,000 to 3,000,000.

More specifically, the present invention relates to an ethylene polymerization method characterized by the Ziegler type catalyst used, particularly its titanium compound component, and the third component added during polymerization.

Conventionally, as a method of improving the performance of polyethylene, a method of increasing the molecular weight by increasing the polymerization rate has been known. It is known that as the molecular weight of polyethylene increases, its impact resistance, abrasion resistance, stress/crack resistance, chemical resistance, etc. improve. Utilizing this property, ultra-high molecular weight polyethylene is used for gears, packing, etc. It is used in industrial materials such as Recently, such ultra-high molecular weight polymers have been attracting attention as raw material polymers for ultra-high strength polyethylene fibers.

In order to produce ultrahigh molecular weight 1 polyethylene, that is, to increase the degree of polymerization of the polymer, it is important to select the type of solid catalyst component, the type of organoaluminum component, and the polymerization conditions.

However, although it is desirable that the solid catalyst component be highly active and provide a high molecular weight polymer, no solid catalyst component that satisfies these two conditions has been known so far.

As organoaluminum components, conventional polymers (3) that provide polyethylene often lack polymerization stability and tend to cause problems such as polymer adhesion and coarse polymer formation.

Regarding polymerization conditions, in order to obtain high molecular value polyethylene, the degree of polymerization is often lowered, which tends to cause various problems such as a decrease in catalyst activity and a decrease in productivity.

From this perspective, it is understood that there are still many points that need to be improved in order to produce ultra-high molecular weight polyethylene with good productivity and under stable polymerization conditions.

The present inventors produce ultra-high molecular weight polyethylene with a molecular weight of 500,000 to 3,000,000 by combining a so-called highly active catalyst component containing titanium, magnesium, and halogen as described above and a specific organic aluminum component. (See Japanese Patent Laid-Open No. 59-68311).

Although it is possible to produce a certain amount of ultra-high molecular weight polyethylene using this method, there are points that require improvement in the molecular weight and polymer properties of the produced polymer, and also in terms of polymerization conditions, it is necessary to raise the polymerization temperature. It was still insufficient, as it was impossible to do so.

1! IJ (7) Ill(ffl) Abstract The present invention provides a solution to the above-mentioned problems, and the weight average molecule a
from a specific solid catalyst component containing Ti, Mq and CI as essential components, an organoaluminum component at a specific concentration, and a specific electron donor compound. The aim is to achieve the above objectives by means of a catalyst system consisting of:

Therefore, the method for producing ultra-high molecular weight polyethylene according to the present invention involves contacting a catalyst system consisting of the following components (A), (B), and (C) with ethylene or a polymerization gas of ethylene and α-olefin. and the weight average molecular weight is 50
It is characterized by producing 10,000 to 3,000,000 polyethylene.

Component (A) A Daegler-type catalyst consisting of a solid composition containing titanium, magnesium and halogen as essential components (hereinafter referred to as component (a)), and 1 gram of olefin having 3 or more carbon atoms as component (a). A composition obtained by prepolymerizing 5 grams or more per portion.

Component (B) Organoaluminum compound Compound having a bond of S i -0-CSB-0-C or P-0-C The present invention uses ultra-high molecular weight polyethylene.
In doing so, the present invention is superior to the prior art mentioned above in points F.

B. Since it is highly active, the so-called decatalyst step can be omitted.

Since there is no need to lower the polymerization temperature to increase the molecular weight, productivity is good.

The above A, oral effects are the component (△) and component (B) according to the present invention.
) and component (C). In other words, component (Δ) is necessary to omit the decatalyst step, and component (B) and component (C
) is necessary to improve productivity.

Conventionally, when α-olefins such as ethylene and propylene are combined with the Mq-containing solid catalyst of component (A>I! (generally M9-supported transition metal catalyst), a polymer with high activity can be obtained. This is known.

However, in order to produce ultrahigh molecular polyethylene using these catalysts, it is necessary to lower the polymerization temperature.
As a result, productivity is low and this catalyst is usually not used. In the present invention, by using a specific organoaluminium component (component 8) and a specific electron donor (component C), the ultrapolymer can be used as an MQ-supported transition metal catalyst component (component A) in the production of polyethylene. It made it possible to use it.

Furthermore, it is often difficult to perform so-called "granulation" of ultra-high molecular weight 1 polyethylene, and polyethylene powder is often used as a commercial product. In that case, the powder form is extremely important. In the present invention, by producing component (A) in a specific manner, it is also possible to produce ultra-high molecular weight i-polyethylene with good powder form.

The catalyst of the present invention comprises component (A), component (B) and component (
C).

Component (A) Component (A) is a solid catalyst component (hereinafter referred to as component (a)) of a Ziegler type catalyst consisting of a solid composition containing titanium, magnesium and halogen as essential components, and an olefin having 3 or more carbon atoms. Ingredient (a) 5 per gram
The sum of mtQ is more than gram.

Component (a), that is, the solid catalyst component of the Daegler-type catalyst having these three components as essential components, is well known including its manufacturing method, and various suitable methods including modifications thereof are available. things are available.

Here, "containing as an essential component" means Ti
, MO and halogen, this indicates that other purposeful additional components may be present. Specifically, for example, elements such as silicon, aluminum, and borax can be included.

Specific examples of component (a) include, for example, JP-A-53-4568.
No. 8, No. 54-3894, No. 54-31092, No. 54-39483, No. 54-94591, No. 54-
No. 118484, No. 54-131589, No. 55-7
No. 5411, No. 55-90510, No. 55-9051
No. 1, No. 55-127405, No. 55-147507
No. 55-155003, No. 56-18609,
No. 56-70005, No. 56-72001, No. 56
-86905, 56-90807, 56-15
No. 5206, No. 57-3803, No. 57-34103
No. 57-92007, No. 57-121003,
No. 58-5309, No. 58-5310, No. 58-5
No. 311, No. 58-8706, No. 58-27732, No. 58-32604, No. 58-32605, No. 5
No. 8-67703, No. 58-117206, No. 58-
No. 127708, No. 58-183708, No. 58-1
No. 83709, No. 59-149905, No. 59-14
No. 9906, various publications, etc. can be found.

Component (a) can be prepared by any convenient method, and some of these methods are described in the above-mentioned publications, but specific examples of preparation methods are as follows: It is as follows.

(a) A method in which a magnesium halide, an electron donor compound, and a titanium-containing compound are brought into contact and, if necessary, treated with a specific solvent.

(b) A method of treating alumina or magnesia with a halogenated phosphorus compound and contacting it with magnesium halogenide, an electron donor compound, and a titanium halogen-containing compound.

(c) A solid component obtained by contacting magnesium halide, titanium tetraalkoxide, and a specific polymeric silicon compound, optionally containing an electron donor compound,
A method of contacting a titanium halide compound and/or a silicon halide compound.

(d) A method in which a magnesium compound is dissolved in a titanium tetraalkoxide and an electron donor compound, and a halogenating agent or a titanium halogen compound is added to the resulting liquid product to precipitate a solid component, in which the titanium compound is brought into contact.

(b) A method in which an organomagnesium compound such as a Grignard reagent is reacted with a halogenating agent, a reducing agent, etc., and then an electron donor compound and a titanium compound are brought into contact with the organomagnesium compound.

(v) A method of contacting an alkoxymagnesium compound with a halogenating agent and/or a titanium compound in the presence or absence of an electron donor compound.

In these methods, the magnesium compounds used include magnesium halide (halogens are basically bromine, but chlorine is particularly preferred), dialkoxymagnesium (alkyl of the alkoxy group is C1-1C1o), alkoxymagnesium halides (for alkoxy groups and halogens see above), magnesium oxyhalides (for halogens see above), dialkylmagnesiums (for alkyl groups see above for alkoxy groups), magnesium oxide, hydroxide Examples include magnesium and magnesium carboxylates (preferably monocarboxylic acid salts having about 1 to 20 carbon atoms).

The titanium compound τ used to produce component (a) has the general formula 4 n X n (where R1 is carbon Ti (OR1
) Hydrogen residue, preferably about 1 to 10 carbon atoms,
, X represents a halogen, and n represents a number of O≦n≦4. ) can be mentioned. A. Systemically L
, T Ha, T1Cl Ti[3r, I, 4゛Ti(CO21-15)C13, T i (OC2H5) 2Cl 2
, Ti (QC2to15) 3CI , Ti
(Oi C3H7) Cl 3 , Ti(
○nC4H9)C13, Ti(○n04to19)2CI2, Ti(Q
C2 15 ) B r 3 , Ti (QC2 15
) (OC4H9) 2 C1, Ti(OnC
4H9)3C1, Ti(OC6H5)C13, Ti(OiC4Hg)2C12, Ti(QCH)CI 5113' Ti(QCH)CH 6133・ri(OC2H5)4, Ti(OnC3H7)4,
T + (OnC48g)4, T i (Oi C489)4, Ti(OnCH) 6 13 4' T ! (OnCBHl 7)4. 1° i Co CHC 1 (C2H5)
C4H9] 4 etc.

Moreover, this titanium compound is TiX'4 (here, X'
represents a halogen) with an electron donor. As a specific example, T1Cl・C
HCOC2] 5, TiC1・CH3Co2C2H5
, 'r i CI , s・C6H5NO2, TiC1・C
)-13GOCI, T1Cl ・CHCOCl, TiCl ・C6H5CO2C2H5, TiC1・C
Examples include ICOC2H5, TiC1・CHO, etc.

It has already been mentioned above that electron donor compounds can be used when preparing component (a).

Examples of electron donors that can be used for producing the solid component (a) include alcohols, phenols, ketones, aldehydes, carboxylic acids, esters with or without 11M, needles, acid amides, Nitrogen-containing electron donors such as acid anhydrides, ammonia, amines, nitriles,
Examples include nitrogen-containing electron donors such as isocyanates.

More specifically, (a) methanol, ethanol, propatool, pentanol, hequinanol, octatool, dodecanol, octadecyl alcohol, benzyl alcohol, phenylethyl alcohol, cumyl alcohol, isopropylbenzyl alcohol and the like having 1 to 18 carbon atoms; alcohols, (b) phenols with 6 to 25 carbon atoms that may have an alkyl group, such as phenol, cresol, xylenol, ethylphenol, probylphenol, cumylphenol, nonylphenol, naphthol; (c) Ketones having 3 to 15 carbon atoms such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, and benzophenone; (d) aldehydes having 2 to 15 carbon atoms such as acetaldehyde, propionaldehyde, octylaldehyde, benzaldehyde, tolualdehyde, and phthaldehyde; (v) Methyl formate, methyl acetate, ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexyl acetate, edyl propionate, methyl butyrate, ethyl valerate,
Ethyl stearate, ethyl chloroacetate, ethyl dichloroacetate, methyl methacrylate, ethyl crotonate, cyclohexanecarboxylate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexyl benzoate, benzoate 1-phenyl fragrant, benzyl benzoate, methyl toluate, ethyl toluate, amyl toluate, ethyl ethylbenzoate,
Methyl anisate, ethyl anisate, ethyl ethoxybenzoate, diethyl phthalate, dibutyl phthalate, dihebdyl phthalate, γ-buty[1 lactone, α-valerolactone, coumarin, phthalide, ethylene carbonate, etc. with 2 carbon atoms]
to 20 organic acid esters, (to) ethyl silicate,
Carbon number of inorganic acid esters such as silicate esters such as butyl silicate and phenyltriethoxysilane, (1.)acetyl chloride, benzoyl chloride, toluic acid chloride, anisyl chloride, phthaloyl chloride, isophthaloyl chloride, etc. 2 to 15 acid halides, (chi)
Carbons such as methyl ether, ethyl ether, isopropyl ether, butyl ether, amyl ether, Te1-rahydrofuran, anisole, diphenyl needle, etc.
2 to 20 ethers (su) acid amides such as acetic acid amide, benzoic acid amide, toluic acid amide, (meth) methylamine, ethylamine, diethylamine, tributylamine, piperidine, tribenzylamine, aniline, pyridine, picoline, Examples include amines such as tetramethylethylenediamine, nitriles such as (l)acetonitrile, benzonitrile, and tolnitrile, and the like. It is also possible to use two or more of these in combination.

The amount of each component constituting component (a) may be arbitrary as long as the effect of the present invention is observed, but is generally preferably within the following range. The amount of titanium compound used is lX10-3 to 10 in molar ratio to magnesium compound.
The amount of halogen used is within the range of 0.00, preferably within the range of 0.01 to 10, and the amount of halogen used is also within the range of 0.1 to 100, preferably 1 in molar ratio to the magnesium compound.
~50.

In addition, when using an electron-donating compound as an optional component, the amount used is 1 x 1 for the magnesium compound.
Within the range of 0-3 to 100, preferably 0.01 to 10
within the range of

Component (A) of the present invention comprises the solid composition, namely component (
a) is prepolymerized with olefin having 3 or more carbon atoms in an amount of 5 g or more per gram of component (a).Here, [prepolymerizing component (a)] means , means that component (a) is used as a solid catalyst component of a Daegler-type catalyst to polymerize an olefin to form a starting polyolefin on component (a). There is no particular limit to the pre-merging conditions. However, the following conditions are generally preferred.

The polymerization temperature is 0 to 80°C, preferably 10 to 60°C. The amount of polymerization is 5 grams or more per gram of solid composition, but due to the nature of prepolymerization, it is usually up to 50 grams. A preferred amount of prepolymerization a is 10 grams to 20 grams.

As the organoaluminum component in the preliminary stage, those generally known as cocatalysts for Ziegler type catalysts can be used.

As a specific example, Al(C2H5)3, A1 (iCH
) A1(nC4H9)3. AI (CH)
AI(Cto1)5 11 3'
8 17 3ゝA l (Cio
H21) 3, A I (C2H5)2CI, A1 (iC4H9)2C1, A I (C2H5)2H, A I (i C4Hg)
2H.

A I (C2H5)2 (OC2H5), etc. are mentioned. Preferred among these are A1(C2H5>3 and A I (i C4Hg)3
, is.

The amount of organoaluminum component used during prepolymerization is AI/Ti (molar ratio) relative to the titanium component in the solid composition.
and is 1 to 20, preferably 2 to 10. Further, during the prepolymerization, an electron donor compound as described above, such as an alcohol, ester, ketone, etc., can be added.

Examples of olefins having 3 or more carbon atoms used during prepolymerization include propylene, 1-butene, 1-hexene, 4-methyl-pentene-1, and the like.

Particularly preferred is propylene.

In this way, the component (A) of the present invention is obtained, in which 5 g or more of an olefin having 3 or more carbon atoms is added to a solid composition containing 1, titanium, magnesium, and halogen as essential components.

Ingredient (B) Component (B) is an organoaluminum compound.

Specific examples include R3-nAIXn or R3-mA1
(OR)m (where R and R3 may be the same or different, a hydrocarbon hydrocarbon residue having about 1 to 20 carbon atoms, or hydrogen;
R4 is a hydrocarbon residue having about 1 to 20 carbon atoms, X is a halogen, and n and m are respectively O≦n<3 and O<m<
This is because of 3. ). Specifically, (a) 1-realkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trihexylaluminum, triethylaluminum, tridecylaluminum, (b) diethylaluminium monochloride, diisobutylaluminum monochloride, Examples include alkylaluminum halides such as ethylaluminum ses-4 nichlorite and ethylaluminum dichloride, (c) diethylaluminum hydride, diisobutylaluminum hydride, and (d) aluminum alkoxides such as diethylaluminum ethoxide and diethylaluminum phenoxide.

These organoaluminum compounds (a) to (c) may contain other organometallic compounds, such as R454 3-aAl(OR)a (1≦a≦3, R and R5 are
They are hydrocarbon residues having about 1 to 20 carbon atoms, which may be the same or different. ) can also be used in combination with an alkyl aluminum alkoxide. For example, a combination of triethylaluminum and diethylaluminum ethoxide, a combination of diethylaluminum monochloride and diethylaluminum ethoxide, a combination of ethylaluminum dichloride and ethylaluminum jetoxide, a combination of triethylaluminum, diethylaluminum ethoxide, and diethylaluminum chloride, Can be used in combination with

Component (C) Component (C) is s 1-o-c, B-0-C or p-
It is a compound that has an oc bond.

These are specifically represented by the following general formulas.

That is, the silicon compound has the general formula % formula % (7) R4-n (where R6 is a hydrocarbon residue having about 1 to 20 carbon atoms or a halogen,
R7 is a hydrocarbon residue having about 1 to 20 carbon atoms, and n is a number satisfying O≦n<4. As a specific example, S i (OCH3) 4.5i (QCH) 5i
(OiC3H7)4. Si(OnCH) 5i(OC
GH5)4. (CH3> S i (OC
H3) 3, (CH3> 28 i
(OCH3) 2 , (CH3) S i
(OC2t15) 3, (C2H5) 28 i
(OC21-15)2, (nC6H11)S i (
OCH3)3, (nCH)Si(OCH3)3. (CH2-CH)Sl(OCH3)3, C1(CH2)
3Si(OCH3)3, (C6H5)S! (OCH
3) 3, (C6H5)Si(OC2H5)3, (C6to15) 28! (OC2H5)
2, (C6H5)2Si(OCH3)2, (C6H5)(CH3)S i (OCH3)2, NC
(CH2>28t (OC2H5)3, (C61-15
)(CH3)Si (OC2H5)2, (nC3H7)
Si(OC2H5)3, (CH3)5 i (OC3H
7) 3, (CH-CH2)St (OC2H5)3, C
H3Si(OCH3)2C12, Si(OC2H5)3CI, Si(QC21-15)2Cl2,S!
(0! 0 3 H7) Cla,
5i (OnC4to19) 2CI 2 , S
i (OC1713) 2Br 2.5i (OCGH
5) 3C1, etc. Among these, preferred are 5t(OCH3)4, Si(OC2H5)4, S
i (OnC41-19)4, (C6H5)Si(OC
2H5)3, (C6H5)S i (OCH3)3, etc.

The boron compound has the general formula RB(OR)3-n (where R
8 is a hydrocarbon residue having approximately 1 to 20 carbon atoms or a halogen, R9 is a hydrocarbon residue having approximately 1 to 20 carbon atoms, and n represents a number of O≦n<3.

Specific examples include B(OCH3)3, B(OCH) B(OnC3H7)3. B(OiC3
H7)3,B (OnC4Hg)3.6133,B (
OCe H5) 3, B (OnCH) B (006 day 4CH3) 3, B (OCH) CI B (OCH3) C12,3
22ゝB (OC2H5)2CI.

B(OC4H9)C12, (CH3)B(OC2H5)2, (02H5)8(OC2H5)2, (06H5)B(OCH3)2, etc.

The phosphorus compound has the following formula: 0≦
(indicating the number n<3). As a specific example,
P(OCH3)3, P(OC2H5)3, P (Ot
C3H7) 3, P(OnCaH7)3, P(OnC4
H9)3, P(OiCH) P(OnCH)4
9 3' 8 15 3'P
(On C1o H21) a, P(OnC17H35)3, P(OCH3)2C1, P(OC2H5)2c1, P
(OC2H5) CI 2, P(OnC4H9)C12, P (CH3)(OC2H5)2, P(02H5)(OCH3)2, PO(OCH3)3, PO(OC2H5) 3, PO
(OnC4H9)3, PO(OCH3)C12, PO(OC2H5)2C1, etc.

In the above definitions of Si, B and P compounds, the preferred hydrocarbon residue having about 1 to 20 carbon atoms is a lower alkyl group or phenyl group, and the preferred halogen is chlorine.

M! II(7):III The catalyst system of the present invention comprises component (A), component (B) and component (C
) is formed by contacting them all at once or in stages.

The use fd of the organoaluminum compound as component (B) is not particularly limited, but it is
~1000. In particular, it is preferably within the range of 10 to 3001.

The amount of component (C) to be used is preferably within the range of 1 x 10-3 to 10 in molar ratio to component (B) of the present invention, preferably 0.
．． It is within the range of 1 to 1.0.

Polymerization The ultra-high molecular weight polyethylene of the present invention is produced by slurry polymerization or gas phase polymerization.

This catalyst system is also effective for continuous polymerization, batch polymerization, or prepolymerization methods. As the polymerization solvent in the case of slurry polymerization, saturated aliphatic or aromatic hydrocarbons such as hexane, heptane, pentane, cyclohexane, benzene, and toluene are used alone or in mixtures.

Polymerization temperature is from room temperature to about 100°C, preferably 50°C
~85°C. It is also possible to copolymerize ethylene with other α-olefins such as propylene, butene-1, hexene-1, etc. in an amount of about 1 to 20 weight percent. The ultra-high molecular weight polyethylene produced by the present invention has a weight average molecular weight of 500,000 to 3,000,000, particularly 600,000 to 3,000,000.
2 million later. The definition and measurement method of heavy weight average molecular weight are well known (for example, "Polyethylene Resin" No. 46
-49 pages (Plastic Materials Course 4) (Nikkan Kogyo Shimbun, published in 1962), etc.].

1) Pour 150 ml of thoroughly degassed and purified n-hebutane into a 1 liter flask that has been purged with nitrogen, and then add M
0.1 mol of (jcI2 (ball mill T: ground for 24 hours) and 0.03 mol of Ti(On04H9)4 were introduced, the temperature was raised to 70°C, and the mixture was stirred for 1 hour.
0.075 mol of n-butanol was introduced and reacted at 70°C for 1 hour. Furthermore, 1 mole of 5iC1O is added to 30
The mixture was introduced at 90° C. and allowed to react at 90° C. for 4 hours. After the reaction is complete,
Washed with n-hebutane. Then dibutyl phthalate 0
．． 02 mol was introduced at 30°C and reacted at 90°C for 1 hour. After the reaction was completed, it was washed with n-hebutane. moreover,
Introducing 425 ml of T iCI at 30°C,
The reaction was carried out at 110°C for 4 hours.

After the reaction was completed, it was washed with n-hebutane to prepare the component (a> for producing component (A). When a part of component (a) was taken out and analyzed for its composition, it was found that it contained Ti. is 3
．． 36 weight was a percentage.

Preliminary Section 8 of (a) In a 1.5 liter stainless steel stirred tank equipped with a stirring and temperature control device, add 750 ml of thoroughly dehydrated and de-Wl-depleted n-hebutane and 3.0 mL of triethylaluminum. 2 grams and 15 grams of component (a) were introduced.

The temperature in the stirring tank was set at 20° C., and propylene was polymerized for 2 hours by introducing bu-copicin at a constant rate. After the polymerization was completed, it was thoroughly washed with n-hebutane. When a part of the product was taken out and propylene polymerization a was investigated,
There were 9.8 grams of propylene per gram of component (a).

2) Polymerization of ethylene In a stainless steel autoclave with an internal volume of 1.5 liters equipped with stirring and temperature control equipment, after repeating the vacuum-ethylene exchange several times, thoroughly dehydrate J3 and 11.
800 milliliters of n-hebutane at a concentration of 52 m is introduced, followed by 100 milligrams of 1-ethylaluminum (B), (C6H5)S i (OC2H5)3 (C) 20.
8 milligrams and 10 milligrams of the catalyst component (A) synthesized above as component (a) were introduced. Furthermore, ethylene was introduced to make the total pressure 6 Ky/d. The temperature was raised to 75°C and polymerization was carried out for 2 hours. These reaction conditions were kept the same during the polymerization.

However, the pressure, which decreases as the chassis advances, was kept constant by introducing only ethylene. After the polymerization was completed, the ethylene was purged and the contents were taken out from the A-tocrepe, and the polymer slurry was filtered and dried in a vacuum dryer overnight.

174 grams of polymer (PE) were obtained.

When the molecular field of the polymerized polymer was measured, lff1
The average molecular weight (hereinafter abbreviated as MW) was 1.53 million. The bulk specific gravity of the polymer was 0.36 (i/CC).

Example-2 1) Production of catalyst component (component (A)) 50 milliliters of dehydrated and deoxygenated n-hebutane was introduced into a flask purged with nitrogen, and then M(
0.1 mol of JCI2 and 0.2 mol of Ti(0-nBu)4 were introduced, and the mixture was reacted at 90°C for 2 hours. After the reaction was completed, the temperature was lowered to 40°C, and 12% of methylhydrodiene polysiloxane (20t7 inch stoke) was added.
A milliliter of the solution was introduced and the reaction was allowed to proceed for 2 hours. The solid component produced was washed with n-hebutane. Then 5iCl
2 moles of O and 50 milliliter of n-heptane were introduced, and the mixture was reacted at 50° C. for 2 hours. After the reaction is complete, n
- Washed with hebutane to obtain component (a). When the composition was analyzed, it was found to be Ti-4,8%.

Prepolymerization treatment of (a) Under the prepolymerization conditions of Example-1, the amount of triethylaluminum used was 2.4 grams, and the prepolymerization R was 1.
Prepolymerization was carried out in exactly the same manner except that the amount was changed to 5.2 grams to obtain component (A>).

2) Polymerization of ethylene Ethylene polymerization was carried out under exactly the same conditions as in Example-1. 133 grams of polymer was obtained.

MW=1.24 million, polymer bulk specific gravity=0.45 <9/C
C).

Comparative Example-1 In the production of component (A>) in Example-2, 'FJ3a of component (A>) was carried out in exactly the same manner except that propylene was not prepolymerized, and the polymerization of ethylene was also carried out in the same manner. .116 grams of polymer were obtained, Mw=122
The bulk specific gravity of the polymer was 0.38 (g/CC).

Example-3 1) Production of catalyst component (component (A)) Dehydrated and deoxygenated n
- 100 ml of hebutane is introduced, then MgC
0.1 mol of 12, 40.195 mol of Ti(On04H9) and 0.007 mol of n-butanol were introduced at 90°C.
Allowed time to react. After the reaction was completed, the temperature was lowered to 35°C and 1
．． 3.5.7-detramethylcyclotetrasiloxane 0
．． 25 mol was introduced and reacted for 4 hours. After the reaction was completed, the produced solid component was washed with n-hebutane. Next, 0.2 mol of 5iCl was introduced at 30°C for 1 hour, and the mixture was reacted at 90°C for 4 hours. Furthermore, 0.01 mol of phthaloyl chloride was introduced at 90°C over 0.5 hours, and the mixture was reacted at 95°C for 1 hour. After the reaction was completed, it was washed with n-hebutane. Then 5ill O, 1 mole to 3
The mixture was introduced at 0°C and reacted at 90°C for 6vt. After the reaction was completed, it was washed with n-hebutane to obtain a solid component (a).

Solid component (a) pre-(!1) Treatment Example-1 pre-(ll[) in place of triethyl aluminum, triethyl aluminum 2.
The same procedure was followed except that a mixture of 8 grams and 0.4 grams of diethyl aluminum was used. )
(△) was v, l.

2) Polymerization of ethylene Polymerization was carried out under exactly the same conditions as in Example 1, except that 75 milligrams of triethylaluminum and 315.6 millidarams of (CH)Si (OC2H5) were used. 213
grams of polymer were obtained.

Mw=1.89 million, polymer bulk specific gravity=0.45 NJ/C
C).

L Crack 21 Under the polymerization conditions of Example-3, without using (CH)S i (OC2H5)3, A
Polymerization was carried out under exactly the same polymerization conditions except that 225 mg of 1(02H5)2(OC21-15) was used. 184 grams of polymer was obtained, Mw = 1,130,000, polymer bulk specific gravity = 0.40 (g/cc).

Comparative Example 3 Component (A) was produced in exactly the same manner as in Example 3, except that the amount of prepolymerization was changed to 2 grams per 1 gram of component (a). did exactly the same thing. 157 grams of polymer was added to 1q, MW = 1.37 million, polymer bulk specific gravity = 0.39 (9/
cc).

Polymerization of ethylene was carried out in exactly the same manner as in Example 3 of 11 and 2 A Two Balls, except that the compound shown in Table 1 was used as component (C). The results are shown in Table-1.

Examples-9 to 10 As component (B) under the polymerization conditions of Practical Example-1, Table-
Ethylene polymerization was carried out in exactly the same manner except that the compound shown in Example 2 was used. The results are shown in Table-2.

Examples 11 to 12 Ethylene polymerization was carried out in exactly the same manner as in Example 2, except that the amount of component (C) used and the polymerization temperature were changed. The results are shown in Table-3.

Claims (1)

[Claims] Ethylene or a mixed gas of ethylene and α-olefin is brought into contact with a catalyst system composed of the following components (A), (B), and (C) to produce a catalyst having a weight average molecular weight of 500,000 yen. A method for producing ultra-high molecular weight polyethylene, characterized in that it produces polyethylene of ~3 million. ¥Component (A)¥ Ziegler-type catalyst consisting of a solid composition containing titanium, magnesium, and halogen as essential components (hereinafter referred to as component (a)), and an olefin having 3 or more carbon atoms as component (a) 1 A composition obtained by prepolymerizing 5 grams or more per gram. ¥Component (B)¥ Organoaluminum compound¥Component (C)¥ Compound having Si-O-C, B-O-C or P-O-C bond