JP3153850B2 - Method for producing ethylene polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an ethylene polymer. More specifically, a novel catalyst comprising a chromium compound, an alumoxane, an organometallic alkoxide and / or an organometallic siloxide is used to produce an ethylene polymer having excellent balance between rigidity and environmental stress cracking (ESCR) and moldability. On how to do it.

[0002]

2. Description of the Related Art Ethylene polymers are generally and widely used as resin materials for various molded articles, and required characteristics differ depending on the molding method and application. For example, a polymer having a relatively low molecular weight and a narrow molecular weight distribution is suitable for a product molded by an injection molding method, but a product having a relatively high molecular weight is suitable for a product molded by inflation molding or blow molding. Polymers having a wide molecular weight distribution are suitable. It has been known that an ethylene polymer having a wide molecular weight distribution suitable for blow molding or the like can be obtained by using a so-called Phillips catalyst in which chromium trioxide is supported on an inorganic oxide such as silica. Further, JP-A-2-123108, JP-A-4-123108
An ethylene polymer having a wide molecular weight distribution suitable for blow molding or the like can also be obtained by single-stage or multi-stage polymerization using a Ziegler catalyst disclosed in JP-A-18407 and JP-A-5-230136.

However, in recent years, there has been a demand for higher quality ethylene polymers suitable for blow molding and the like. When a blow molded article is produced using an ethylene polymer having a wide molecular weight distribution obtained by the above catalyst, the molded article has (1) an insufficient balance between rigidity and environmental stress cracking (ESCR). (2) Regarding the molding, the melt tension is not sufficient, so that not only the thickness of the blow molded product is uneven, but also the surface of the molded product is rough, which is not desirable in appearance. It is not always satisfactory in any of these points. Recently, Japanese Patent Application Publication No. 7-503739 discloses a method for obtaining an ethylene polymer having a wide molecular weight distribution by using a catalyst comprising a chromium compound and alumoxane. However, it is hard to say that the ethylene-based polymer obtained by this method has a sufficient level of balance between rigidity and environmental stress cracking (ESCR) and melt tension. Also, JP-A-2-10580
6. JP-A-2-185506 discloses a solid catalyst component in which chromium trioxide is supported on an inorganic oxide carrier, alumoxane,
There is disclosed a method for obtaining an ethylene polymer having a wide molecular weight distribution by using a catalyst comprising an organoaluminum alkoxide or an organoaluminum siloxide. However, the ethylene-based polymer obtained by this method is not at a sufficient level in terms of the balance between rigidity and environmental stress cracking (ESCR) and the melt tension. Further, Japanese Patent Application Laid-Open No. Sho 54-12029
No. 0 discloses a method for obtaining an ethylene polymer having a wide molecular weight distribution by using a catalyst comprising an alumoxane and a solid component in which a chromate ester is supported on silica and then treated with an organoaluminum alkoxide. However, the ethylene polymer obtained by this method also does not have a sufficient balance between rigidity and environmental stress cracking (ESCR) and melt tension.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the above-mentioned problems and to improve rigidity and resistance to environmental stress cracking (ESC).
An object of the present invention is to provide a method for efficiently producing an ethylene polymer having excellent balance of R) and excellent moldability.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned problems, and as a result, have found that ethylene comprising a catalyst comprising a chromium compound, an alumoxane, an organometallic alkoxide and / or an organometallic siloxide is used. The object has been solved by a method for producing a polymer. That is, the present invention provides: [1] a chromium compound selected from chromium carboxylate, chromium-1,3-diketo compound, chromate ester and chromamide compound, alumoxane , and organic aluminum
Alkoxide, organoaluminum siloxide, yes
Magnesium alkoxide, organic boron alkoxide
An organometallic alkoxide and / or an organometallic siloxide selected from the group consisting of a specific surface area of 50 to 1000 m ² /
g, the pore volume is 0.5-3.0 cm ³ / g, and the average particle size is
Using a carrier of 10 to 200 μm,
A method for producing an ethylene-based polymer, characterized by using a catalyst having 0.05 to 5.0 wt% supported as atoms , [2] a chromium carboxylate, a chromium-1,3-diketo compound, a chromate ester, after the chromium compound selected from Kuromuamido compound supported on a carrier, further alumoxane, on which is characterized by using a catalyst supported organometallic alkoxide and / or organometallic siloxide
The method for producing an ethylene-based polymer according to the above [1] , [3] after supporting a chromium compound selected from a chromium carboxylate, a chromium-1,3-diketo compound, a chromate ester and a chromamide compound on a carrier. , An alumoxane, and then a catalyst in which an organometallic alkoxide and / or an organometallic siloxide are sequentially supported, wherein the method for producing an ethylene-based polymer according to the above [1] or [2] ,

[4] The compounding ratio of the chromium compound and the alumoxane in the catalyst is 0.5 to 100 as the ratio of aluminum atom / chromium atom in the alumoxane, and the ratio of the metal atom in the organometallic alkoxide and / or the organometallic siloxide is The molar ratio of chromium atoms is 0.5 to 100, and the alumoxane and the organometallic alkoxide and / or
Or, the molar ratio of the organometallic siloxide is 0.01 to 100.
The above items [1] to either method for producing an ethylene polymer according to [3], [5] the carrier to the above [1] to an inorganic metal oxides and / or inorganic halides [4] Write in either
Method for producing ethylene polymer of the mounting, [6] an alumoxane on a alkylalumoxanes
[1] The method for producing an ethylene-based polymer according to any one of [1] to [5] . The above objectives have been achieved by developing.

Hereinafter, the present invention will be described specifically. As the chromium compound (excluding chromium oxide) used in the catalyst of the present invention, a chromium carboxylate, a chromium-1,3-diketo compound, a chromate ester, and a chromamide compound are suitable. As the chromium carboxylate, chromium (II) or chromium (III) represented by the general formula (1) or (2)
The compound of.

[0008]

Embedded image

Embedded image

(R ¹ , R ² , R ³ , R ⁴ , and R ⁵ are each hydrogen or a hydrocarbon group having 1 to 18 carbon atoms, and may be the same or different.) , Chromium formate (II), chromium acetate (I
I), chromium (II) propionate, chromium (II) butyrate,
Chromium pentanoate (II), chromium hexanoate (II), 2
-Chromium (II) ethylhexanoate, chromium benzoate (I
I), chromium naphthenate (II), chromium oleate (I
I), chromium oxalate (II), chromium formate (III), chromium (III) acetate, chromium (III) propionate, chromium (III) butyrate, chromium (III) pentanoate, chromium (III) hexanoate, 2 -Chromium ethylhexanoate (III
), Chromium benzoate (III), chromium naphthenate (III)
), Chromium (III) oleate, chromium oxalate (III)
And the like, and chromium (II) acetate, chromium (II) 2-ethylhexanoate, chromium (III) acetate and chromium (III) 2-ethylhexanoate are preferred.

As the chromium-1,3-diketo compound,
A chromium (III) complex having one or three 1,3-diketo compounds represented by the general formula (3). _{CrX k Y m Z n ··· (} 3) (X is a 1,3-diketo type chelate ligand, Y and Z are selected from halogen, alkoxy, aryloxy, alkyl, aryl, amide, in the same K + m + n = 3, 1 ≦ k ≦ 3) Specific examples include chromium-1,3-butanedionate,
Chromium acetylacetonate, chromium-2,4-hexanedionate, chromium-2,4-heptanedionate,
Chromium-2,4-octandionate, chromium-3,5
Octandionate, chromium benzoylacetonate, chromium-1,3-diphenyl-1,3-propanedionate, chromium-2-methyl-1,3-butanedionate, chromium-2-ethyl-1,3- Butanedionate, chromium-2-phenyl-1,3-butanedionate, chromium-1,2,3-triphenyl-1,3-propanedionate and the like are mentioned, and chromium acetylacetonate is preferred.

The chromate ester is represented by the general formula (4)
Is a compound of chromium (VI) represented by

Embedded image (R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , and R ¹¹ each have 1 carbon atom.
To 18 hydrocarbon groups, which may be the same or different. M ¹ and M ² each represent a carbon atom or a silicon atom. As specific examples, when M ¹ and M ² are carbon, bis (tert-butyl) chromate, bis (1,1-dimethylpropyl) chromate, bis (2-phenyl-2-
Propyl) chromate, bis (1,1-diphenylethyl) chromate, bis (triphenylmethyl) chromate, bis (1,1,2,2-tetramethylpropyl) chromate, bis (1,1,2-trimethylpropyl) Chromate and the like are preferable, and bis (tert-butyl) chromate is preferable.

When M ¹ and M ² are silicon, bis (trimethylsilyl) chromate, bis (triethylsilyl) chromate, bis (tributylsilyl) chromate, bis (triisopentylsilyl) chromate, bis (tri-2-ethyl) (Xylsilyl) chromate, bis (tridecylsilyl) chromate, bis (tri (tetradecyl) silyl) chromate, bis (tribenzylsilyl) chromate, bis (triphenethylsilyl) chromate, bis (triphenylsilyl) chromate, bis (tritolyl) (Silyl) chromate, bis (trixylsilyl) chromate, bis (trinaphthylsilyl) chromate, bis (dimethylphenylsilyl) chromate,
Bis (diphenylmethylsilyl) chromate, bis (dimethyltexylsilyl) chromate, bis (dimethylisopropylsilyl) chromate, bis (tert-butyldimethylsilyl) chromate, bis (tri-tert)
-Butylsilyl) chromate, bis (triethylphenylsilyl) chromate, bis (trimethylnaphthylsilyl) chromate, polydiphenylsilylchromate, polydiethylsilylchromate and the like, with bis (triphenylsilyl) chromate being preferred.

As the chromamide compound, there can be mentioned chromium (II) or chromium (III) compound represented by the general formula (5) or (6).

Embedded image (R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ ,
R ²⁰ , R ²¹ , R ²² and R ²³ each represent hydrogen or a group having 1 to 1 carbon atoms.
18 hydrocarbon groups, which may be the same or different. M ³ , M ⁴ , M ⁵ and M ^{6 each} represent a carbon and / or silicon atom, L represents a ligand such as ether or nitrile, and 0 ≦ p ≦ 2. )

[0014]

Embedded image (R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , R ³¹ ,
^R32 , ^R33 , ^R34 , ^R35 , ^R36 , ^R37 , ^R38 , ^R39 , R
⁴⁰ R ⁴¹ is hydrogen or a hydrocarbon group having 1 to 18 carbon atoms, and may be the same or different. M ^7, M
⁸ , M ⁹ , M ¹⁰ , M ¹¹ , M ¹² are carbon and / or silicon atoms. )

As specific examples, bis (bistrimethylsilylamide) chromium (II) -THF complex, bis (bistrimethylsilylamide) chromium (II) -diethyl ether complex, bis (methyltrimethylsilylamide) chromium (II) -THF complex , Bis (methyltrimethylsilylamide) chromium (II) -diethyl ether complex, bis (t
tert-butyltrimethylsilylamide) chromium (II)
-THF complex, bis (tert-butyltrimethylsilylamide) chromium (II) -diethyl ether complex, bis (phenyltrimethylsilylamide) chromium (II) -T
HF complex, bis (phenyltrimethylsilylamide) chromium (II) -diethyl ether complex, tris (dimethylamido) chromium (III), tris (diethylamido) chromium (III), tris (diisopropylamido) chromium (III), tris (methyl) Phenylamide) chromium (II
I), tris (diphenylamide) chromium (III), tris (bistrimethylsilylamide) chromium (III),
Tris (bistriethylsilylamide) chromium (III
), Tris (bistriphenylsilylamide) chromium (III) and the like, and tris (bistrimethylsilylamide) chromium (III) is preferred.

Alumoxane is a compound well known in the art, but its preparation and structure are Polyhed.
ron, 9, 429-453 (1990), Ziegl
erCatalysts, G. et al. Fink et al.
(Eds.) 57-82, Springer-Verl.
ag (1995). The alumoxane used in the present invention is represented by the following general formula (7)
Or the compound represented by (8) is mentioned.

Embedded image

Embedded image (R ⁴² is a methyl group, an ethyl group, a propyl group, n- butyl group, a hydrocarbon group such as an isobutyl group, preferably, 100 to .q 1 is a methyl group, an isobutyl group
, Preferably 4 or more, particularly preferably 8 or more. The method for producing this type of compound is known and, for example, salts such as pentane, hexane, heptane, cyclohexane, decane, benzene and toluene, which are salts having water of crystallization (copper sulfate hydrate, aluminum sulfate hydrate, etc.) Examples thereof include a method of producing a suspension by adding a trialkylaluminum to a suspension of an active hydrocarbon solvent, and a method of allowing solid, liquid or gaseous water to act on the trialkylaluminum in a hydrocarbon solvent.

Further, an alumoxane represented by the general formula (9) or (10) may be used.

Embedded image

Embedded image (R ⁴³ is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, and is preferably a methyl group or an isobutyl group. Further, R ⁴⁴ is a methyl group, an ethyl group, propyl group, n- butyl group, a hydrocarbon group such as an isobutyl group or a chlorine, a halogen or hydrogen bromine, is selected from hydroxyl, exhibit different radicals from R ^43. Further, R ⁴⁴ is either the same or different R is usually a number from 1 to 100, preferably 3 or more,
r + s is 2 to 101, preferably 6 or more. )

In the compound of the general formula (9) or (10), (O-Al (R ⁴³ )) _r unit and (O-Al
( ^R44 )) The _s units may be connected in blocks or may be connected regularly or irregularly at random. The method for producing such an alumoxane is the same as that for the above-described alumoxane of the general formula. Instead of using one kind of trialkylaluminum, two or more kinds of trialkylaluminum are used, or one or more kinds of dialkylaluminum monohalide or dialkylaluminum are used. It is good to use aluminum monohydride or the like.

Examples of the organometallic alkoxide and / or organometallic siloxide used in the present invention include a group of organometallic alkoxides and / or organometallic siloxides of Group 2 or 13 of the periodic table. , (12), (13) or (14). R ⁴⁵ _t A1 (OR ⁴⁶ ) _3-t (11) (R ⁴⁵ and R ⁴⁶ are a hydrocarbon group having 1 to 18 carbon atoms and may be the same or different. T is 1 Or 2.) R ⁴⁷ R ⁴⁸ R ⁴⁹ Si—O—AlR ⁵⁰ R ⁵¹ (12) (R ⁴⁷ , R ⁴⁸ , R ⁴⁹ , R ⁵⁰ and R ⁵¹ are hydrocarbons having 1 to 18 carbon atoms. R ⁵² Mg (OR ⁵³ ) (13) (R ⁵² and R ⁵³ are hydrocarbon groups having 1 to 18 carbon atoms and are the same. R ⁵⁴ _u B (OR ⁵⁵ ) _3-u (14) (R ⁵⁴ and R ⁵⁵ are hydrocarbon groups having 1 to 18 carbon atoms and are the same and May also be different. U is 1 or 2.)

General formula (11) R ⁴⁵ _t, A1 (OR ⁴⁶ ) _3-t (11) (R ⁴⁵ and R ⁴⁶ are hydrocarbon groups having 1 to 18 carbon atoms, and Specific examples of the organoaluminum alkoxide represented by t) are dimethylaluminum methoxide, dimethylaluminum ethoxide, dimethylaluminum isopropoxide, dimethylaluminum n-butoxide, Dimethylaluminum isobutoxide, diethylaluminum ethoxide, diethylaluminum isopropoxide, diethylaluminum n-butoxide, diethylaluminum isobutoxide, diisobutylaluminum ethoxide, diisobutylaluminum isopropoxide, diisobutylaluminum n-butoxide,
Diisobutylaluminum isobutoxide, di-n-hexylaluminum ethoxide, di-n-hexylaluminum isopropoxide, di-n-hexylaluminum n
-Butoxide, di-n-hexylaluminum isobutoxide, methylaluminum dimethoxide, methylaluminum diethoxide, methylaluminum diisopropoxide, methylaluminum din-butoxide, methylaluminum diisobutoxide, ethylaluminum diethoxide, ethylaluminum Diisopolopoxide,
Ethyl aluminum di-n-butoxide, ethyl aluminum diisobutoxide, isobutyl aluminum diethoxide, isobutyl aluminum diisopropoxide,
Isobutylaluminum di-n-butoxide, isobutylaluminum diisobutoxide, n-hexylaluminum diethoxide, n-hexylaluminum diisopropoxide, n-hexylaluminum din-butoxide, n-hexylaluminum diisobutoxide and the like. .

Of these, dimethyl aluminum methoxide, dimethyl aluminum ethoxide, dimethyl aluminum isopropoxide, dimethyl aluminum n-
Butoxide, dimethyl aluminum isobutoxide, diethyl aluminum ethoxide, diethyl aluminum isopropoxide, diethyl aluminum n-butoxide, diethyl aluminum isobutoxide, diisobutyl aluminum ethoxide, diisobutyl aluminum isopropoxide, diisobutyl aluminum n-butoxide, diisobutyl aluminum isobutoxide And monoalkoxides such as di-n-hexylaluminum ethoxide, di-n-hexylaluminum isopropoxide, di-n-hexylaluminum n-butoxide, and di-n-hexylaluminum isobutoxide.

These compounds can be easily synthesized by known methods. For example, the method by reaction with an alcohol represented by the trialkyl aluminum Nim the general formula R ⁴⁶ OH represented by the general formula R ⁴⁵ ₃ A1 or the general formula R ^45,
₃ Trialkylaluminum represented by A1 and general formula A
Although there is a method of obtaining by an exchange reaction with an aluminum trialkoxide represented by 1 (OR ⁴⁶ ) ₃ , the former is preferred in the present invention.

General formula (12): R ⁴⁷ R ⁴⁸ R ⁴⁹ Si—O—AlR ⁵⁰ R ⁵¹ (12) (R ⁴⁷ , R ⁴⁸ , R ⁴⁹ , R ⁵⁰ and R ^{51 each} have 1 to 18 carbon atoms. Specific examples of the organoaluminum siloxide represented by the following formulas: trimethyldimethylsiloxyalane, trimethyldiethylsiloxyalane, trimethyldiisobutylsiloxyalane, and trimethyldioxide n-hexylsiloxyalan, triethyldimethylsiloxyalan, triethyldiethylsiloxyalan, triethyldiisobutylsiloxyalan, triethyldi-n-hexylsiloxyalan, triphenyldimethylsiloxyalan, triphenyldiethylsiloxyalan, triphenyldiisobutylsiloxyalan, triphenyldin-hexyl Lucyloxyalan and the like.

Of these, trimethyldimethylsiloxyalan, trimethyldiethylsiloxyalan, trimethyldiisobutylsiloxyalan, trimethyldi-n-hexylsiloxyalan, triethyldimethylsiloxyalan, triethyldiethylsiloxyalan, triethyldiisovitylsiloxyalan, triethyldin-yl Hexylsiloxyalan is preferred.

The above-mentioned organoaluminum siloxides are: 1) Reaction of a silanol compound represented by the general formula R ⁴⁷ R ⁴⁸ R ⁴⁹ Si—OH with an organoaluminum compound represented by the general formula R ⁵⁰ R ⁵¹ RAl 2) a reaction between a cyclic siloxane and an organoaluminum compound represented by the general formula R ⁵⁰ R ⁵¹ RAl; 3) a known method by reacting a polysiloxane with an organoaluminum compound represented by the general formula R ⁵⁰ R ⁵¹ RAl Can be synthesized.

[0026] 1) to 3) in, R ⁴⁷ R ⁴⁷ ~R ⁵¹ in the general formula ^{R 47 R 48 R 49 Si-} O-AlR 50 R 51 ~R
⁵¹ is the same as R, and R represents the general formula R ⁴⁷ R ⁴⁸ R ⁴⁹ Si-OA
are those equivalent to R ⁴⁷ to R ⁵¹ in lR ⁵⁰ R ^51, represents a group which is substituted in the reaction.

General formula (13): R ⁵² Mg (OR ⁵³ ) (13) (R ⁵² and R ⁵³ are hydrocarbon groups having 1 to 18 carbon atoms and may be the same or different. Specific examples of the organomagnesium alkoxide represented by the formula: ethyl magnesium methoxide, ethyl magnesium ethoxide,
Ethyl magnesium isopropoxide, ethyl magnesium n-butoxide, ethyl magnesium isobutoxide, ethyl magnesium phenoxide, butyl magnesium methoxide, butyl magnesium ethoxide, butyl magnesium isopropoxide, butyl magnesium n-butoxide, butyl magnesium isobutoxide,
Examples thereof include butylmagnesium phenoxide, and preferred are ethylmagnesium ethoxide, ethylmagnesium isopropoxide, ethylmagnesium n-butoxide, and ethylmagnesium isobutoxide.

These compounds can be easily synthesized by a known method. For example, there is a method obtained by reacting a dialkylmagnesium represented by the general formula R ⁵² ₂ Mg with an alcohol represented by the general formula R ⁵³ OH.

General formula (14): R ⁵⁴ _UB (OR ⁵⁵ ) ₃ -U (14) (R ⁵⁴ and R ⁵⁵¹ are hydrocarbon phases having 1 to 18 carbon atoms,
They may be the same or different. u is 1 or 2. Specific examples of the organoboron alkoxide represented by) include dimethylmethoxy borane, dimethyl ethoxy borane, dimethyl propoxy borane, dimethyl butoxy borane, diethyl methoxy borane, diethyl ethoxy borane, diethyl propoxy borane, diethyl butoxy borane, methyl dimethoxy borane, Methyl diethoxy borane, methyl dipropoxy borane, methyl dibutoxy borane, ethyl dimethoxy borane, ethyl diethoxy borane, ethyl dipropoxy borane, ethyl dibutoxy borane, phenyl dimethoxy borane, phenyl diethoxy borane, phenyl dipropoxy borane, phenyl di Butoxyborane, diphenylmethoxyborane, diphenylethoxyborane, diphenylpropoxyborane, diphenylbutoxyborane and the like. That.

Of these, dimethyl methoxy borane, dimethyl ethoxy borane, dimethyl propoxide borane,
Dimethyl butoxy borane, diethyl methoxy borane, diethyl ethoxy borane, diethyl propoxy borane, and diethyl butoxy borane are preferred. These compounds can be easily synthesized by a known method. For example, a Grignard reagent represented by the general formula R ⁵⁴ MgX (X is a halogen) or an organolithium reagent represented by the general formula R ⁵⁴ Li, and a borate represented by the general formula B (OR ⁵⁵ ) ₃ And a method of obtaining the same by an exchange reaction. The organometallic alkoxides and organometallic siloxides represented by the general formulas (11), (12), (13), and (14) may be used alone or in combination of two or more.

The catalyst of the present invention is used by being supported on a carrier commonly used as a component of an ethylene polymerization catalyst, such as an inorganic oxide or an inorganic halide. The inorganic oxide used for the carrier is an oxide of a metal belonging to Group 2, 4, 13, or 14 of the periodic table, and specifically, magnesia, titania, zirconia, alumina, aluminum phosphate, silica, silica Examples include titania, silica-zirconia, silica-alumina, or a mixture thereof. In the present invention, the specific surface area is 50 to 1000 m ^2.
/ G, preferably 200-800 m ² / g, pore volume 0.5-3.0 cm ³ / g, preferably 1.0-2.5.
cm ³ / g and an average particle diameter of 10 to 200 μm, preferably 50 to 150 μm are used.

These inorganic oxides can be heated to a temperature of 100 to 100 ° C. in a stream of dry nitrogen gas under a molecular sieve.
Those fired at 900 ° C. for 10 minutes to 24 hours are preferably used. It is preferable to perform calcination in a solid fluid state with a sufficient amount of nitrogen gas.

As the inorganic halide used for the carrier,
The metal belonging to Group 2 or 13 of the periodic table is a halide, such as magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, aluminum chloride, gallium chloride, or a mixture thereof. As a method for obtaining a catalyst using the above constituent components, a method of introducing a chromium compound, an alumoxane, an organometallic alkoxide and / or an organometallic siloxide, and a carrier into a reactor for preparing a catalyst in advance to form a catalyst is used. Among them, a method of supporting an alumoxane and an organometallic alkoxide and / or an organometallic siloxide after supporting a chromium compound on a carrier is preferred. More preferably, after the chromium compound is supported on the carrier, alumoxane is first supported, and then the organometallic alkoxide and / or organometallic siloxide is supported.

The supporting reaction of each component is preferably carried out in an inert hydrocarbon solvent such as propane, butane, isobutane, pentane, hexane, heptane, cyclohexane, decane, benzene, toluene and xylene. Carrier 1
Any amount of solvent per g can be used. Further, after the supporting reaction, the supported catalyst can be separated from the solvent by a method such as removing the solvent under vacuum or separating by filtration. The amount of the chromium compound supported on the carrier is such that the chromium atom is 0.05 to 5.0 w
The amount is preferably such that the loading amount is t%, preferably 0.05 to 2.0 wt%. The amount of alumoxane supported is
Molar ratio of aluminum atom to chromium atom is 0.5 to 10
The amount which becomes 0 is preferable. The amount of the supported organometallic alkoxide and / or organometallic siloxide is preferably such that the molar ratio of metal atoms to chromium atoms in the organometallic alkoxide and / or organometallic siloxide is 0.5 to 100. The molar ratio of alumoxane to the organometallic alkoxide and / or organometallic siloxide is preferably such that the molar ratio is from 0.01 to 100. The supporting reaction temperature is from 0 ° C. to the boiling point of the solvent, and the treatment and reaction time is from 5 minutes to 2 minutes.
4 hours.

In carrying out the method of the present invention, the production of the ethylene polymer of the present invention using the above-mentioned catalyst requires a liquid phase polymerization method such as slurry polymerization or solution polymerization or a gas phase polymerization method. And so on. Liquid phase polymerization is usually carried out in a hydrocarbon solvent, and the hydrocarbon solvent may be used alone or as a mixture of inert hydrocarbons such as propane, butane, isobutane, hexane, cyclohexane, heptane, benzene, toluene and xylene. .
The polymerization temperature in liquid or gas phase polymerization is generally 0.
-300 ° C, and practically 20-200 ° C.
In addition, hydrogen or the like can coexist in the polymerization reactor for controlling the molecular weight. Further, if necessary, α-olefins such as propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene can be copolymerized alone or in a mixture of two or more α-olefins. .

[0036]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The measurement methods used in Examples and Comparative Examples are shown below. a) Pretreatment of polymer for measurement of physical properties: Using a plastograph manufactured by Toyo Seiki Co., Ltd., 0.2 wt% of B225 manufactured by Ciba Geigy was added as an additive, and the mixture was kneaded at 190 ° C. for 7 minutes in a nitrogen atmosphere. b) Molecular weight, molecular weight distribution: gel permeation chromatography (G
PC) to determine a number average molecular weight (Mn) and a weight average molecular weight (Mw). The molecular weight distribution is Mn of Mw
The ratio (Mw / Mn) is expressed as follows: The larger the Mw / Mn, the wider the molecular weight distribution. The measurement conditions in GPC are as follows.・ Apparatus: WATERS 50C model ・ Column: Shodex-HT806M ・ Solvent: 1,2,4-trichlorobenzene ・ Temperature: 135 ° C. ・ Sample concentration: 2 mg / 5 ml ・ Universal evaluation using monodispersed polyethylene fraction c) Melt flow Rate: 190 ° C. under a load of 21.6 kgf according to JIS K-7210, Table 1, Condition 7.
The measured value in was shown as HLMFR. d) Density: Measured according to JIS K-7112. e) Melt tension: using a melt tension tester manufactured by Toyo Seiki Co., Ltd., resin temperature 210 ° C., orifice diameter 2.1
mm, orifice length 8mm, extrusion speed 15mm / m
in and the winding speed was 6.5 min. f) Rigidity: The flexural modulus measured according to JIS K-7203 was used as the value of rigidity. g) ESCR: The F50 value measured by the BTL method according to JIS K-6760 was used as the ESCR value.

Example 1 (1) Synthesis of trimethyldiethylsiloxyalane 1.0 m of triethylaluminum manufactured by Tosoh Akzo
o1 / liter-hexane solution 44.4m1 at 0-5 ° C
After cooling, 5.6 m of trimethylsilanol manufactured by Shin-Etsu Chemical Co., Ltd.
1 (50 mmol) was added dropwise. Thereafter, the mixture was stirred at 25 ° C. for 30 minutes, and trimethyldiethylsiloxyalane 1.0 m
ol / liter-hexane solution. (2) Preparation of catalyst 500 ° C. was placed in a 100 ml flask previously purged with nitrogen.
Crossfield's ES70 grade silica (fired for 6 hours at a specific surface area of 320 m ² / g, pore volume of 2.0 c)
4.0 g of m ³ / g, average particle size of 40 μm) and further 40 ml of n-hexane were added to form a slurry. To this slurry was added 1.5 ml of a 0.1 mol / l-hexane solution of chromium (III) 2-ethylhexanoate (STREM Co., Ltd., 0.20 wt% of chromium atoms), and the mixture was added at 25 ° C. for 15 minutes.
Stirred for minutes. At the end of this time, 1.5 ml of a 1.0 mol / l-hexane solution of isobutylalumoxane manufactured by Tosoh Akzo was added, and the mixture was stirred at 25 ° C for 30 minutes. At the end of this time, 0.5 ml of a 1.0 mol / l-hexane solution of trimethyldiethylsiloxyalane synthesized in the above (1) was further added.
For a minute. Removal of the solvent under vacuum gave a free flowing, supported catalyst.

(3) Gas phase polymerization Eur. Polym. J. , Vol. 21,245 (1
985), a vertical vibration type reactor (capacity: 150 cm ³ , diameter: 5) similar to the fluidized bed reactor described in US Pat.
0 mm, vibration speed 420 times / min (7 Hz), vibration distance 6
cm) and gas phase polymerization was performed. A reactor in which 120 mg of the catalyst obtained in the above (2) was sealed in an ampoule under a nitrogen atmosphere was put into a reactor which had been previously purged with nitrogen, heated to 85 ° C., and then pressurized with 14 kg / cm ² of ethylene. The polymerization was started by starting and cracking the ampoule.
Ethylene was fed as needed via flexible joints to maintain the ethylene pressure in the reactor.
After the polymerization reaction was performed at 89 ° C. for 2 hours, the feeding of ethylene was stopped, the reactor was cooled to room temperature, degassed, and the contents were taken out. The yield of the white particulate polyethylene was 20 g. The measurement results of physical properties are shown in Table 1.

(Example 2) In the same manner as in Example 1 except that 0.5 ml of a 1.0 mol / l-hexane solution of diethylaluminum ethoxide manufactured by Tosoh Akzo was added instead of trimethyldiethylsiloxyalane. As a result of preparing a catalyst and performing a polymerization reaction, 22 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1.

Example 3 Instead of chromium (III) 2-ethylhexanoate, a 0.1 mol / l-toluene solution of chromium acetylacetonate manufactured by Wako Pure Chemical Industries, Ltd.
A catalyst was prepared and the polymerization reaction was carried out in the same manner as in Example 1 except that 5 ml (chromium atom carrying amount 0.20 wt%) was added and the polymerization temperature was changed to 82 ° C, and as a result, 18 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1.

Example 4 Instead of chromium (III) 2-ethylhexanoate, a 0.1 mol / l-toluene solution of chromium acetylacetonate manufactured by Wako Pure Chemical Industries, Ltd.
5 ml (chromium atom carrying amount 0.20 wt%) was added, and instead of trimethyldiethylsiloxyalane,
1.0m of Akzo's diethylaluminum ethoxide
A catalyst was prepared in the same manner as in Example 1 except that 0.5 ml of an ol / liter-hexane solution was added, and then a polymerization reaction was performed in the same manner as in Example 1 except that the polymerization temperature was changed to 82 ° C. As a result, 19 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1.

Example 5 (1) Synthesis of bis (triphenylsilyl) chromate According to the method described in US Pat. No. 2,863,891, chromium trioxide was reacted with triphenylsilanol to form bis (triphenylsilanol). Phenylsilyl) chromate was synthesized. (2) Preparation of catalyst and polymerization 500 ° C. was placed in a 100 ml flask which had been previously replaced with nitrogen.
Crossfield's ES70 grade silica (fired for 6 hours at a specific surface area of 320 m ² / g, pore volume of 2.0 c)
4.0 g of m ³ / g, average particle size of 40 μm) and further 40 ml of n-hexane were added to form a slurry. To this slurry was added a solution of bis (triphenylsilyl) chromate synthesized in the above (1) in a 0.1 mol / liter-hexane solution 1.5.
ml (chromium atom carrying amount 0.20 wt%)
Stirred at 150C for 15 minutes. At the end of this time, 1.5 ml of a 1.0 mol / l-toluene solution of methylalumoxane manufactured by Tosoh Akzo was added, and the mixture was stirred at 25 ° C. for 30 minutes. At the end of this time, 1.0 m of trimethyldiethylsiloxyalane synthesized in (1) of Example 1 was further added.
ol / liter-hexane solution (0.5 ml)
Stirred at C for 30 minutes. Removal of the solvent under vacuum gave a free flowing, supported catalyst. Using the catalyst obtained above, a polymerization reaction was carried out in the same manner as in Example 1 except that the polymerization temperature was 85 ° C. As a result, 25 g of polyethylene was obtained. Table 1 shows the measurement results of the physical properties.

Example 6 The same procedure as in Example 5 was carried out except that 0.5 ml of a 1.0 mol / l-hexane solution of diethylaluminum ethoxide manufactured by Tosoh Akzo was added instead of trimethyldiethylsiloxyalane. The catalyst was prepared and polymerized under the same conditions.
0 g of polyethylene was obtained. Table 1 shows the measurement results of the physical properties.

Example 7 (1) Synthesis of bis (tert-butyl) chromate Synth. Commun. , 10, 905 (198
According to the method described in 0), chromium trioxide and ter
Bis (tert-butyl) chromate was synthesized by reaction with t-butanol. (2) Preparation and polymerization of catalyst In Example 5, 0.5 ml of a 1.0 mol / l-hexane solution of diethylaluminum ethoxide manufactured by Tosoh Akzo was added in place of trimethyldiethylsiloxyalane, and bis (triphenylsilyl) was further added. ) Instead of chromate, bis (ter) synthesized in (1) above
1.5 ml of a 0.1 mol / l-hexane solution of t-butyl) chromate (chromium atom carrying amount 0.20 wt
%), Except that the catalyst was prepared and polymerized in the same manner as in Example 5 to obtain 32 g of polyethylene. The measurement results of physical properties are shown in Table 1.

Example 8 (1) Synthesis of diethylethoxyborane Justus Liebigs Ann. Chem. ,
352 (1975), N, N
-Diethylethoxyborane was synthesized by reacting triethylborane with ethanol using diethylpivalamide as a catalyst. (2) Preparation and Polymerization of Catalyst Instead of bis (triphenylsilyl) chromate, a 0.1 mol / liter-hexane solution of bis (tert-butyl) chromate synthesized in (1) of Example 7 was used.
5 ml (chromium atom carrying amount 0.20 wt%) was added to 1.5 ml of a 1.0 mol / l-hexane solution of isobutylalumoxane manufactured by Tosoh Akzo Co. instead of methylalumoxane. Further, trimethyldiethylsiloxyalane was added. Instead, the catalyst was prepared in the same manner as in Example 5 except that 0.5 ml of a 1.0 mol / l-hexane solution of diethylethoxyborane synthesized in the above (1) was added. 30 g of polyethylene were obtained. The measurement results of physical properties are shown in Table 1.

Example 9 (1) Synthesis of tris (bistrimethylsilylamide) chromium (III) Chem. Soc. (A), 1433 (1971).
According to the method described in (1), tris (bistrimethylsilylamide) chromium (III) was synthesized by reacting chromium anhydride with lithium bistrimethylsilylamide. (2) Preparation and Polymerization of Catalyst Instead of bis (triphenylsilyl) chromate, 1.5 ml of a 0.1 mol / liter-hexane solution of tris (bistrimethylsilylamide) chromium (III) synthesized in (1) above was used. Atom loading 0.20 wt%)
Example 5 except that the polymerization temperature was changed to 92 ° C.
As a result of preparing the catalyst in the same manner as above and performing polymerization in the same manner,
22 g of polyethylene were obtained. The measurement results of physical properties are shown in Table 1.

Example 10 (1) Synthesis of ethylmagnesium ethoxide Chem. Soc. (A), 1118 (1968).
, Ethyl magnesium ethoxide was synthesized by reacting diethyl magnesium with ethanol. (2) Preparation and polymerization of catalyst Instead of bis (triphenylsilyl) chromate, 0.1 mol / liter of tris (bistrimethylsilylamide) chromium (III) synthesized in (1) of Example 9
Hexane solution 1.5ml (Chromium atom carrying amount 0.20w
t%) and 0.5 mol of a 1.0 mol / l-hexane solution of ethylmagnesium ethoxide synthesized in the above (1) instead of trimethyldiethylsiloxyalane.
A catalyst was prepared in the same manner as in Example 5 except that ml was added, and polymerization was carried out in the same manner. As a result, 24 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1.

(Example 11) (Slurry polymerization) 500 ml of dehydrated n-hexane was placed in a 1-liter autoclave equipped with a stirrer, which had been previously replaced with nitrogen.
And Crossfield E used in Example 5.
Instead of S70 grade silica, 952 grade silica manufactured by Devison (calculated at 500 ° C. for 6 hours) (specific surface area: 30)
0 m ² / g, pore volume 1.6 cm ³ / g, average particle size 80
μm) and using a 1.0 mol / liter-hexane solution of diethylaluminum ethoxide manufactured by Tosoh Akzo Co., Ltd. in place of trimethyldiethylsiloxyalane.
Except for adding 5 ml, 400 mg of a free-flowing catalyst prepared in the same manner as in Example 5 was charged. After the temperature of the autoclave was raised to 86 ° C., ethylene was injected under pressure of 28 kg / cm ^2, and slurry polymerization was carried out while feeding ethylene as needed so as to maintain this pressure. The polymerization temperature was maintained at 88 ° C. for 1 hour by external cooling. At the end of this time the ethylene feed was stopped, the autoclave was allowed to cool to 70 ° C, vented and the contents were removed. The yield of the white particulate polyethylene was 125 g. The measurement results of physical properties are shown in Table 1.

Example 12 Instead of bis (triphenylsilyl) chromate in Example 5, 0.1 mol / liter of tris (bistrimethylsilylamide) chromium (III) synthesized in (1) of Example 9 -Hexane solution 1.5ml (Chromium atom carrying amount 0.20wt
%), Except that catalyst was prepared in the same manner as in Example 5 to obtain a free-flowing catalyst. Using the catalyst thus prepared, except that the polymerization temperature was set to 95 ° C,
Slurry polymerization was performed in the same manner as in Example 11. As a result, 84 g of white particulate polyethylene was obtained. The measurement results of physical properties are shown in Table 1.

Comparative Example 1 A catalyst was prepared and polymerization was carried out in the same manner as in Example 1 except that trimethyldiethylsiloxyalane was not added. As a result, 18 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1. The balance between the rigidity and the ESCR was worse than that of the first embodiment.

Comparative Example 2 A catalyst was prepared and polymerized in the same manner as in Example 3 except that trimethyldiethylsiloxyalane was not added. As a result, 15 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1. Rigidity and E
The SCR balance was worse than in Example 3, and the value of the melt tension was lower than in Example 3.

Comparative Example 3 A catalyst was prepared and polymerization was carried out in the same manner as in Example 5 except that trimethylethylsiloxyalane was not added. As a result, 20 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1. Rigidity and E
The SCR balance was worse than in Example 5, and the value of the melt tension was lower than in Example 5.

Comparative Example 4 A catalyst was prepared and polymerization was carried out in the same manner as in Example 7 except that diethyl aluminum ethoxide was not added. As a result, 28 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1. Rigidity and ES
The CR balance was worse than in Example 7, and the value of the melt tension was lower than in Example 7.

Comparative Example 5 A catalyst was prepared and polymerized in the same manner as in Example 9 except that trimethyldiethylsiloxyalane was not added. As a result, 18 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1. Rigidity and E
The SCR balance was worse than in Example 9 and the value of the melt tension was lower than in Example 9.

Comparative Example 6 Slurry polymerization was carried out in the same manner as in Example 11 except that the catalyst of Comparative Example 3 was used.
As a result, 104 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 1. Example 1 Balance between rigidity and ESCR
The value of the melt tension was lower than that of Example 11 and worse than that of Example 11.

Comparative Example 7 Instead of using a catalyst comprising a chromium compound, an alumoxane, an organometallic alkoxide and / or an organometallic siloxide in the present invention,
Phillips catalyst supporting chromium trioxide on silica [W. R. The 969ID catalyst purchased from Grace Corporation (1.0 wt% of supported Cr) was calcined in air at 600 ° C. for 30 hours. Polymerization was performed under the same conditions as in Example 11 to obtain 120 g of polyethylene. The measurement results of physical properties are shown in Table 1. Rigidity and ES
The CR balance was worse than in Examples 1 to 12, and the value of the melt tension was lower than in Examples 1 to 12.

(Comparative Example 8) (1) Preparation of catalyst To 30 g of unsintered ES70 grade silica manufactured by Crossfield, an aqueous solution of chromium trioxide was added at room temperature so that the chromium atom carrying amount was 0.20 wt%. Impregnated. After evaporating water, it was calcined in air at 600 ° C. for 30 hours. 4.0 g of the above-mentioned chromium trioxide-supported silica and 40 ml of n-hexane were added to a 100 ml flask previously purged with nitrogen to form a slurry. 1.0 m of isobutylalumoxane manufactured by Tosoh Akzo Co., Ltd.
ol / liter-hexane solution (1.5 ml)
Stirred at 30 ° C for 30 minutes. At the end of this time, 0.5 ml of a 1.0 mol / l-hexane solution of trimethyldiethylsiloxyalane synthesized in Example 1 (1) was further added.
The mixture was stirred at 25 ° C. for 30 minutes. Removal of the solvent under vacuum gave a free flowing, supported catalyst. (2) Polymerization Polymerization was carried out under the same conditions as in Example 1 to obtain 10 g of polyethylene. Table 1 shows the measurement results of the physical properties. The balance between rigidity and ESCR was worse than in Examples 1 to 12, and the value of melt tension was lower than in Examples 1 to 12.

Comparative Example 9 (1) Preparation of Catalyst A catalyst was prepared in the same manner as in Example 6 except that methylalumoxane was not added. (2) Polymerization 400 mg of the catalyst obtained in the above (1) and 0.1 mol / liter of methylalumoxane manufactured by Tosoh Akzo Co., Ltd.
Slurry polymerization was carried out in the same manner as in Example 11 except that 1.5 ml of the toluene solution was charged. As a result, 18 g of polyethylene was obtained. As compared with Example 11, the polymerization activity was remarkably low. The measurement results of physical properties are shown in Table 1. Rigidity and E
The SCR balance was worse than in Example 11, and the value of the melt tension was lower than in Example 11.

[0059]

[Table 1]

Example 13 In the polymerization of Example 7,
Polymerization was carried out under the same conditions as in Example 7 except that the polymerization temperature was 95 ° C., to obtain 38 g of polyethylene. The measurement results of physical properties are shown in Table 2. (Example 14) In the polymerization of Example 7, 0.2% of hydrogen was added.
Kg / cm ² and the polymerization temperature was 78 ° C.
Polymerization was carried out under the same conditions as in Example 7 to obtain 21 g of polyethylene. The measurement results of physical properties are shown in Table 2.

Comparative Example 10 For comparison with Example 13, a catalyst was prepared in the same manner as in Example 7 except that diethyl aluminum ethoxide was not added and the polymerization temperature was 95 ° C. Was carried out to obtain 32 g of polyethylene.
The measurement results of physical properties are shown in Table 2. The balance between the rigidity and the ESCR was worse than in Example 13, and the value of the melt tension was lower than in Example 13.

(Comparative Example 11) Instead of using a catalyst comprising a chromium K compound, an alumoxane, an organometallic alkoxide and / or an organometallic siloxide in the present invention, a Phillips catalyst in which chromium trioxide is supported on silica [W. R. Example 11 except that 0.49 g of a 969 MSB catalyst (a 1.9 wt% Cr support) purchased from Grace Corporation was calcined in air at 820 ° C. for 18 hours) was used alone and the polymerization temperature was set to 100 ° C. Polymerization was carried out in the same manner as described above. As a result, 150 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 2. The balance between rigidity and ESCR was worse than in Examples 13 and 14, and the value of the melt tension was lower than in Examples 13 and 14.

Example 15 In the polymerization of Example 6,
3 ml of 1-hexene was introduced into the reactor under pressure with ethylene,
Polymerization was performed under the same conditions as in Example 6 except that copolymerization was performed. As a result, 35 g of polyethylene was obtained. The measurement results of physical properties are shown in Table 2.

[0064]

[Table 2]

[0065]

According to the present invention, an ethylene polymer having excellent balance between rigidity and environmental stress cracking (ESCR) and excellent moldability can be produced efficiently.
Industrially valuable.

[Brief description of the drawings]

FIG. 1 is a flowchart for preparing a catalyst used in the present invention.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-9-25314 (JP, A) JP-A-9-25312 (JP, A) JP-A-9-136912 (JP, A) JP-A-2- 105806 (JP, A) JP-A-2-185506 (JP, A) JP-A-54-120290 (JP, A) JP-A-9-25313 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) C08F 4/60-4/70

Claims (6)

(57) [Claims] 1. A chromium carboxylate, chromium-1,3-
Chromium compounds selected from diketo compounds, chromate esters and chromamide compounds, alumoxanes and organic
Aluminum alkoxide, organic aluminum siloxy
, Organic magnesium alkoxide, organic boron alcohol
An organometallic alkoxide and / or an organometallic siloxide selected from oxides having a specific surface area of 50 to 1000 m
² / g, pore volume of 0.5 to 3.0 cm ³ / g, average grain
Use a carrier with a diameter of 10 to 200 μm, and
A method for producing an ethylene-based polymer, comprising using a catalyst in which 0.05 to 5.0 wt% is supported as a rom atom . 2. Chromium carboxylate, chromium-1,3-
2. The catalyst according to claim 1, wherein a chromium compound selected from a diketo compound, a chromate ester and a chromamide compound is supported on a carrier, and then a catalyst further supporting alumoxane, an organometallic alkoxide and / or an organometallic siloxide is used. A method for producing an ethylene polymer. 3. Chromium carboxylate, chromium-1,3-
Diketo compounds, after a chromic acid ester and chromium compound selected from Kuromuamido compound supported on a carrier, claims, characterized in that the use of alumoxane, and then carried in the order of the organometallic alkoxide and / or organometallic siloxide catalyst 3. The method for producing an ethylene-based polymer according to 1 or 2 . 4. The catalyst according to claim 1, wherein a mixing ratio of the chromium compound and the alumoxane in the catalyst is 0.5 to 100 as an aluminum atom / chromium atom ratio in the alumoxane, and a metal atom in the organometallic alkoxide and / or organometallic siloxide is chromium. The ethylene-based polymer according to any one of claims 1 to 3, wherein the molar ratio of atoms is 0.5 to 100, and the molar ratio of alumoxane to organometallic alkoxide and / or organometallic siloxide is 0.01 to 100. Manufacturing method of coalescence. 5. The method for producing an ethylene polymer according to claim 1, wherein the carrier is an inorganic metal oxide and / or an inorganic halide. 6. The alumoxane method for producing ethylene polymer according to any one of 5 to claim 1 is alkyl alumoxanes.