JP3017817B2 - Method for producing ethylene polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Background of the Invention]

FIELD OF THE INVENTION The present invention relates to a process for providing ethylene polymers having a medium molecular weight distribution.

[0002]

2. Description of the Related Art Ethylene polymers are used for different purposes depending on their molecular weight distribution. Those having a wide molecular weight distribution are used for hollow molded articles such as pipes, and those having a medium molecular weight distribution are used for fibers and tapes. In addition, those having a narrow molecular weight distribution are often used for injection molded articles such as bottle caps and buckets.

Conventionally, solid catalyst components comprising magnesium halide and titanium halide, which are known to have high activity, generally provide an ethylene polymer having a narrow molecular weight distribution, so that injection molding products such as bottle caps and buckets are used. A catalyst component that is suitable for production but is generally not suitable for the production of other uses as described above.

In recent years, in order to expand applications, it has been necessary to develop a catalyst that gives a polymer having a wide molecular weight distribution. For example, a method of using many kinds of transition metal compounds, a method of supporting a catalyst component on an inorganic oxide carrier, and the like. (For example, Japanese Patent Publication Nos. 52-37037 and 53-85).
No. 88, No. 55-8006, No. 57-45247,
Nos. 58-13084 and 62-58364).

The present inventors have proposed a solid catalyst component which is already extremely excellent in particle morphology and which is particularly suitable for slurry polymerization or gas phase polymerization, by converting component (A-1) of the present invention to (1) silicon halide or ( A method has been proposed in which the preparation is carried out by treating with 2) titanium halide or (3) titanium halide and hydropolysiloxane (for example, JP-A-58-127706, JP-A-61-285203, JP-A-61-285204). No. 61-285205, No. 5
Nos. 7-180612, 58-5309, 58-5
No. 311). Although these catalysts are useful as such, it has been desired that the resulting polymer has a narrow molecular weight distribution and further improvement in catalytic activity.

Further, the component (A-1) may be replaced by (1) an aluminum halide or (2) an aluminum halide,
Also, a catalyst by treating with a halide of titanium or silicon, or (3) an organoaluminum compound or hydropolysiloxane, and an aluminum halide has been proposed (for example, see JP-A-59-1).
2903 and 59-43007).
However, they give polymers with relatively high activity and a broad molecular weight distribution, but solid particles are often agglomerated during the aluminum halide reaction, which has been a major problem for industrial practice.

Further, a catalyst has been proposed by treating the component (A-1) with an organoaluminum compound and a halide of titanium or silicon (for example, JP-A-58-225104). However, the activity and the molecular weight distribution are not at a satisfactory level, and their improvement has been desired.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ethylene polymer having a high activity and a moderately wide molecular weight distribution, particularly by using a specific catalyst. It is to achieve the purpose.

[0009]

[Summary of the Invention] <Summary> The process for producing an ethylene polymer according to the present invention comprises adding a catalyst comprising the following components (A) and (B) to ethylene or ethylene and carbon. It is characterized by contacting and polymerizing α-olefins of Formulas 3 to 10. Component (A) Component (A-2), (A-3),
(A-4) A solid component for a Ziegler catalyst obtained by sequentially contacting (A-5), component (A-1) , the following component (A-1-i), and component (A-1-ii) ) And component (A-1-iii), a component (A-1-i) magnesium dihalide, component (A-1-ii) titanium tetraalkoxide and / or polytitanate, component (A -1-iii) (R ¹ is a hydrocarbon residue) A polymer silicon compound having a structure represented by the following formula: (A-2) a silicon halide, (A-3) an organoaluminum compound, and (A-4) a halogenated carbon. Hydrogen, component (A-5) an organic or halogen compound of aluminum, and component (B) an organoaluminum compound.

<Effects> According to the present invention, an ethylene polymer having a high activity and a moderately wide molecular weight distribution can be stably produced on an industrial scale. Such an ethylene polymer is particularly useful as a resin for producing fibers or tapes.

[Specific description of the invention] <Catalyst> The catalyst used in the present invention comprises the following components (A) and (B). Here, “consisting of” means that the component is indicated (ie,
(A) and (B)),
It does not preclude the coexistence of other ingredients where appropriate.

<Component (A)> Component (A) includes components (A-2), (A-3) and (A-
4) A solid component for a Ziegler catalyst obtained by sequentially contacting (A-5). Here, the term "obtained by contact" includes not only a contact product of the listed components but also a product obtained by contact with other suitable components.

Component (A-1) 1) Constituents Component (A-1) is derived from the following component (A-1-i), component (A-1-ii) and component (A-1-iii) Solid catalyst component. Here, “consisting of” means that the component is indicated (that is, (A-1-i), (A-1-i)
It does not mean that i) and (A-1-iii)) are the only ones, but does not exclude the coexistence of other components that are suitable. Needless to say, “consisting of” does not necessarily mean that the indicated compound is present in its original form.

The solid catalyst component (A-1) is neither magnesium dihalide nor a complex of magnesium dihalide and titanium tetraalkoxide or polytitanate, but is another solid. At present, its contents have not been sufficiently analyzed, but according to the results of the composition analysis,
This solid composition contains titanium, magnesium, halogen and silicon. This solid catalyst component (A
The specific surface area of -1) is often small, usually 10 m ^2.
/ G or less, and according to the result of X-ray diffraction, no peak characteristic of magnesium dihalide is observed in this solid component (A), and this is different from magnesium dihalide in X-ray. It seems to be a compound of

(1) Component (A-1-i) This is magnesium dihalide, and specific examples include MgF ₂ , MgCl ₂ , and MgBr ₂ . Of these, MgCl ₂ is preferred.

(2) Component (A-1-ii) This is a titanium tetraalkoxide and / or polytitanate.

Examples of the titanium tetraalkoxide include Ti (OC ₂ H ₅ ) ₄ and Ti (O-iC ₃ H ₇ ).
_{4, Ti (O-nC 3} H 7) 4, Ti (O-nC
_{4 H 9) 4, Ti (} O-iC 4 H 9) 4, Ti (O-t
_{C 4 H 9) 4, Ti} (O-C 5 H 11) 4, Ti (O-C
₆ H ₁₃ ) ₄ , Ti (O—C ₇ H ₁₅ ) ₄ , Ti (O—C _{8
H 17) 4, Ti (O} -C 10 H 21) 4, and the like.

As polytitanate,

[0019]

Embedded image

The following is used. Where R
^{2 to} R ⁵ are each independently a hydrocarbon residue, particularly a C 1 group;
~ 20, especially about 1-6, where n is 2
The above numbers, especially about 2 to 10 are provided. Specifically, for example, tetra-normal butyl polytitanate (polymerization degree n = 2 to 10), tetranormal hexyl polytitanate (polymerization degree n = 2 to 10), or tetra-octyl polytitanate (polymerization degree n = 2) To 10). Of these _{Ti (O-C 4 H 9} ) 4 is preferred.

(3) Component (A-1-iii) The polymer silicon compound has the formula Has a structure shown by the following as a repeating unit.
Here, R ¹ has about 1 to 10 carbon atoms, particularly about 1 to 6 carbon atoms,
, Preferably an alkyl group, a phenyl group and an alkyl-substituted phenyl group. Therefore,
Specific examples of the polymer silicon compound having such a structural unit include methylhydropolysiloxane, ethylhydropolysiloxane, phenylhydropolysiloxane,
And cyclohexyl hydropolysiloxane.

Although the degree of polymerization of the polymer silicon compound is not particularly limited, it is preferable that the viscosity be about 1 to 100 centistokes in consideration of handling. The terminal structure of the hydropolysiloxane has no significant effect, but is preferably blocked with an inert group such as a trialkylsilyl group.

2) Production The component (A-1) is composed of the components (A-1- (i)) to
It can be produced by contacting (A-1- (iii)).

(1) Amount ratio The amount of each component used may be any amount as long as the effects of the present invention are recognized, but generally, the following ranges are preferred.

The amounts of the titanium tetraalkoxide and the polytitanate (component (A-1-ii)) used (the total amount when used in combination) are the same as those of the magnesium dihalide (component (A
With respect to -1-i)), the molar ratio may be in the range of 0.1 to 10, preferably in the range of 1 to 4.

The polymer silicon compound (component (A-1-ii)
i)) is used in an amount of magnesium dihalide (component (A)
With respect to -1-i)), the molar ratio may be in the range of 1 × 10 ^{-2 to} 100, preferably in the range of 0.1 to 10.

(2) Contact Method The solid component (A-1) of the present invention is obtained by bringing the above-mentioned three components into contact. The contacting of the three components can be carried out by any generally known method. In general, -1
What is necessary is just to make it contact in the temperature range of 00 degreeC-200 degreeC. The contact time is usually about 10 minutes to 20 hours.

The above-mentioned three components are preferably brought into contact with stirring, and may be brought into contact with each other by mechanical pulverization using a ball mill, a vibration mill or the like. The order of contact of the three components may be any order as long as the effects of the present invention are recognized, but it is general that the magnesium dihalide and the titanium tetraalkoxide are contacted, and then the polymer silicon compound is contacted. The contact of the three components can also be performed in the presence of a dispersion medium. In this case, examples of the dispersion medium include hydrocarbons, halogenated hydrocarbons, and dialkylpolysiloxanes. Specific examples of the hydrocarbon include hexane, heptane, toluene, and cyclohexane, and specific examples of the halogenated hydrocarbon include n-butyl chloride, 1,2-dichloroethylene, carbon tetrachloride, and chlorobenzene. Specific examples of the dialkyl polysiloxane include dimethyl polysiloxane and methyl-phenyl polysiloxane.

At this time, as disclosed in JP-A-59-80406, an alcohol and an organic acid ester can be used together for the purpose of controlling the properties of the catalyst.

Before contacting the solid component (A-1) with the component (A-2), unnecessary components such as the component (A-1-i)
The unreacted components of i) and (A-1-iii) are washed away. As the washing solvent to be used, an appropriate solvent can be selected from the above dispersion media. Therefore, the component (A-
If the contact of 1-i) to (A-1-iii) is performed in a dispersion medium, the washing operation can be reduced.

The halides of silicon component (A-2) component (A-2), the general formula ^{R 6}
_m SiX _4-m (R ⁶ is a hydrocarbon residue (preferably having about 1 to 10 carbon atoms) or a hydrocarbyloxy group (preferably having about 1 to 10 carbon atoms), X is halogen, and m is Which represents an integer of 0 to 2). Preferred are silicon trihalides, particularly preferred are silicon tetrahalides. Specific examples of such compounds include SiCl ₄ , CH ₃ SiCl ₃ ,
(C ₂ H ₅ ) SiCl ₃ , (C ₄ H ₉ ) SiCl ₃ , P
_{h-Si-Cl 3 (Ph} : _{phenyl), (C 2 H 5)} 2
SiCl ₂ , (C ₂ H ₅ O) SiCl ₃ , (C ₂ H
₅ O) ₂ SiCl ₂ , CH ₃ (C ₂ H ₅ O) SiC
_{l 2, C 2 H 5 (} C 2 H 5 O) SiCl 2 , etc. is.

The organoaluminum compound of component component (A-3) (A-3) is the general formula R
^{_{7 a (R 8 O) b}} AlX 3-ab (R 7 and ^{R 8} are a hydrocarbon residue of each 1 to 12 carbon atoms, X is hydrogen or halogen, 0 <a ≦ 3,0 ≦ b ≦ 2) in It is a compound represented. Further, two or more of these may be used in combination. In the present invention, among them, trialkylaluminum, alkylaluminum monohalide and alkylaluminum monoalkoxide can be preferably used.
Specifically, Al (CH ₃ ) ₃ , Al (C ₂ H ₅ ) ₃ , Al (iC ₄
H ₉ ) ₃ , Al (C ₆ H ₁₃ ) ₃ , (C ₂ H ₅ ) ₂ Al
H, (iC ₄ H ₉ ) ₂ AlH, (CH ₃ ) ₂ AlCl,
(C ₂ H ₅ ) ₂ AlCl, (iC ₄ H ₉ ) ₂ AlCl,
(C ₂ H ₅ ) _3/2 AlCl _3/2 , CH ₃ AlCl ₂ , C
_{2 H 5 AlCl 2, i-} C 4 H 9 AlCl 2, (C 2 H
₅ ) ₂ Al (OC ₂ H ₅ ), (C ₂ H ₅ ) Al (OC _{2
H 5) Cl, (C 2} H 5) 2 AlBr and _C 2 _H 5 A
and the like.

The halogenated hydrocarbon component (A-4) Component (A-4) is 1 to 2 carbon atoms
It has a structure in which part or all of the hydrogen of the hydrocarbon compound 0 is substituted with halogen. Specifically, CH ₃ C
1, CHCl ₃ , C ₂ H ₅ Cl, CH ₃ Cl—CH ₃ C
_{l, C 4 H 9 Cl,} C 8 H 17 Cl, Ph-Cl, o-P
h'Cl ₂ (Ph ': phenylene), _Ph-CH 2 C
1, CFCl ₃ , CCl ₄ , CH ₃ Br, C ₃ H ₇ B
r, C ₄ H ₉ Br, CH ₃ I and the like. Among them, n-C
_{3 H 7 Cl, i-C} 3 H 7 Cl, n-C 4 H 9 Cl, i
_{-C 4 H 9 Cl, sec-} C 4 H 9 Cl, t-C 4 H 9
_{Cl, i-C 3 H 7} Br, n-C 4 H 9 Br may be preferably used.

[0034] Component (A-5) organic or halogenated compounds of aluminum component (A-5) has the general formula ^{_{R 9 c (R 10 O)}} d AlX 3-cd (R
⁹ and R ¹⁰ are each a hydrocarbon residue having 1 to 12 carbon atoms, X is hydrogen or halogen, 0 ≦ c ≦ 3, 0 ≦ d ≦
It is a compound represented by 1). Further, two or more of these may be used in combination. In the present invention, among them, a halogen compound of aluminum can be preferably used.
Specifically, Al (CH ₃ ) ₃ , Al (C ₂ H ₅ ) ₃ , Al (iC ₄
H ₉ ) ₃ , Al (C ₆ H ₁₃ ) ₃ , (C ₂ H ₅ ) ₂ Al
H, (iC ₄ H ₉ ) ₂ AlH, (CH ₃ ) ₂ AlCl,
(C ₂ H ₅ ) ₂ AlCl, (iC ₄ H ₉ ) ₂ AlCl,
(C ₂ H ₅ ) _3/2 AlCl _3/2 , CH ₃ AlCl ₂ , C
_{2 H 5 AlCl 2, i-} C 4 H 9 AlCl 2, Al (O
_{C 2 H 5) Ci 2,} Al (OC 4 H 9) Cl 2, (C 2
H ₅ ) ₂ Al (OC ₂ H ₅ ), (C ₂ H ₅ ) Al (OC
_{2 H 5) Cl, (C} 2 H 5) 2 AlBr and _C 2 _{H 5}
AlI, AlCl ₃ , AlBr _{3 and the} like.

<Synthesis of Component (A)> The component (A) is
Component (A-1) is replaced with components (A-2), (A-3) and (A-
4) Compound (A-5) is synthesized by sequentially and stepwise contact.

(1) Amount ratio The amount of each component used is arbitrary as long as the effects of the present invention are recognized, but the following ranges are generally preferred.

The amount of component (A-2) used is
The molar ratio with respect to Ti in 1) may be in the range of 0.01 to 20, preferably 0.1 to 10.

The amounts of the components (A-3), (A-4) and (A-5) are all based on the molar ratio of Ti in the solid component after the treatment of the component (A-2). 0.1-20, preferably 0.3-10.

(2) Contact method: Component (A-2) to Component (A-) with respect to Component (A-1)
In the contact of 5), at any stage, the temperature is −50 ° C. to 20 ° C.
The reaction is usually performed at 0 ° C. for about 5 minutes to 20 hours.

The contact of each component is preferably carried out with stirring, and may be carried out by mechanical pulverization using a ball mill, vibration mill or the like, but is preferably carried out in the presence of a dispersion medium. The dispersion medium at that time is the component (A-1)
The same ones used when manufacturing the same can be used.

After the reaction between the component (A-1) and the component (A-2), and further after the reaction with the component (A-3), unnecessary components in the dispersion medium are generally removed. (A-4) and (A-5) generally employ a method of removing unnecessary components after continuously reacting without removing unnecessary components. Therefore, the components (A-4) and (A-5) can be reacted in advance and used.

<Component (B)> The component (B) is an organoaluminum compound. In the present invention, a trialkylaluminum, particularly one in which the alkyl has about 1 to 12 carbon atoms can be preferably used. Specifically, Al (CH ₃ ) ₃ , A
1 (C ₂ H ₅ ) ₃ , Al (iC ₄ H ₉ ) ₃ , Al (C ₆
H _{13) 3,} there is isoprenyl aluminum. Also,
General formula R ¹¹ _c AlX _{3 -c} (R ¹¹ is a hydrocarbon residue having 1 to 12 carbon atoms, X is hydrogen, a halogen atom or a hydrocarbyloxy group (preferably having about 1 to 12 carbon atoms), c
Represents 1 or 2) can also be used in combination. Specific examples of such an organoaluminum compound include (CH ₃ ) ₂ AlCl,
(C ₂ H ₅ ) ₂ AlCl, (iC ₄ H ₉ ) ₂ AlCl,
(C ₂ H ₅ ) ₂ AlH, (iC ₄ H ₉ ) ₂ AlH, (C
_{2 H 5) 2 Al (OC} 2 H 5), (iC 4 H 9) 2 Al
(OC ₂ H ₅ ), (C ₂ H ₅ ) ₂ Al (OiC
_{4 H 9), (C 2} H 5) 3/2 AlCl 3/2, C 2 H 5 A
lCl ₂ , iC ₄ H ₉ Al (OC ₂ H ₅ ) ₂ , iC ₄ H
₉ Al (OC ₄ H ₉ ) ₂ , (C ₂ H ₅ ) ₂ AlBr,
(C ₂ H ₅ ) ₂ AlI and the like. Also, alumoxanes formed by the reaction of a trialkylaluminum compound with H ₂ O can be used.

<Polymerization of Ethylene> Copolymerization of ethylene and ethylene with an α-olefin having 3 to 10 carbon atoms up to 10 mol% is carried out using a slurry polymerization method, a gas phase polymerization method, or a solution polymerization method. The present invention can be applied to continuous polymerization, batch polymerization, or prepolymerization. In the case of slurry polymerization, hydrocarbons such as butane, pentane, hexane, heptane, cyclohexane, benzene, and toluene are used. The polymerization temperature is from room temperature to 200 ° C, preferably from 50 to 150 ° C. As is well known, the adjustment of the molecular weight is generally performed using hydrogen.

The ethylene polymer of the present invention thus obtained has a medium to low molecular weight distribution. That is, the melt index (ASTM) at a load of 10 kg and a load of 2.16 kg of the ethylene polymer according to the present invention was used.
D-1238-73): 9
As mentioned above, especially, it is 9.5 or more (the upper limit is about 12), and in the case of copolymerization, it is 8.5 or more (the upper limit is about 11).

[0045]

EXAMPLES Example 1 (1) Synthesis of Component (A-1) 100 ml of dehydrated and deoxygenated n-heptane was introduced into a flask having an inner diameter of 10 cm, which had been sufficiently purged with nitrogen.
Next, 0.1 mol of MgCl ₂ , Ti (O-nC
0.2 mol of ₄ H ₉ ) ₄ was introduced and reacted at 95 ° C. for 1 hour. The diameter of the stirring blade used at that time was 6 cm.
After the reaction was completed, the temperature was lowered to 40 ° C., 15 ml of methyl hydrogen polysiloxane was introduced, and the reaction was carried out at a stirring rotation speed of 20 rpm for 3 hours.

After completion of the reaction, the formed solid component was washed with n-heptane, a part thereof was taken out, and the average particle size was measured by a sedimentation method. T
The i loading rate was 13.5 wt%.

[0047] (2) component (A-1) and component (A-2) and the reaction sufficiently _{N 2} substituted 500cc flask above (A-1)
60 g of the ingredients were added and heptane was added to make a total of 330 cc. 36 cc of SiCl ₄ over 25 minutes at 25 ° C. (vs. T
(imol ratio 1.86) was added dropwise and reacted for 3 hours.
The temperature was raised to 90 ° C., and the reaction was further performed for 3 hours. Then, it was sufficiently washed with heptane. The Ti loading was 4.0 wt%.

(3) Reaction with Components (A-3) and (A-4) 3.4 g of the above solid component was placed in a 500 cc flask, and heptane was added to make 100 cc. 0.35 g of diethylaluminum chloride (15 wt% solution of heptane) (molar ratio to Ti: 1) was added dropwise at 25 ° C. over 30 minutes.
The reaction was performed at 0 ° C. for 2 hours. Then, it was sufficiently washed with heptane. The Ti loading was 4.3 wt%.

(4) Reaction with Components (A-4) and (A-5) 2.8 g of the above solid component was taken, and heptane was added to make 100 cc. N-butyl chloride at 25 ° C 1.15
g (to a Ti molar ratio of 5), 0.95 g of ethyl aluminum dichloride (to a Ti molar ratio of 3) (heptane 10 wt% solution) was added dropwise, and the mixture was reacted at 50 ° C. for 2 hours.
Thereafter, it was thoroughly washed with heptane. The Ti loading was 1.82 wt%.

(5) Ethylene Polymerization 800 ml of sufficiently dehydrated and deoxygenated n-heptane was introduced into a 1.5 liter stainless steel autoclave having a stirring and temperature control device, followed by triethyl aluminum. 100 milligrams,
Five milligrams of the catalyst component synthesized above was introduced.

The temperature was raised to 90 ° C., and hydrogen was supplied at a partial pressure of 3 kg / c.
m ² , and 6 kg / cm ^{2 of} ethylene.
g / cm ² G. Polymerization was performed for 2 hours. During the polymerization, these conditions were kept constant. After the completion of the polymerization, ethylene and hydrogen were purged, the contents were taken out of the autoclave, and the polymer slurry was filtered and dried all day and night. 165 g of polymer were obtained (solid catalyst yield: P
Y = 33000 g-PE / g solid catalyst), MI (2.16 kg
0.94, FR (10kg)
The ratio of the load to the 2.16 kg load is a measure of the molecular weight distribution. The larger this value, the wider the molecular weight distribution) is 10.3.

<Examples 2 to 8, Comparative Example 1> Example
Using component (A-2) synthesized in the same manner as in Example 1, component (A)
-3) was added as shown in Table 1, and the component (A) was further added at the same molar ratio to Ti as in Example-1.
-4) and (A-5) were performed to synthesize the component (A), and the results of polymerization in the same manner as in Example 1 are summarized in Table 1.

The components (A-3), (A-4) and (A
-5) Untreated component (A-2) The performance of the solid catalyst up to the reaction is shown in Comparative Example 1. This has a narrower molecular weight distribution than that of the present invention.

[0054]

[Table 1]

[0055]

The ethylene polymer produced using the catalyst of the present invention is highly active, has a moderately wide molecular weight distribution, and is suitable for producing fibers and tapes. Means for Solving the Problems ".

[Brief description of the drawings]

FIG. 1 is a flowchart for assisting understanding of the technical contents of the present invention.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-135203 (JP, A) JP-A-3-39303 (JP, A) JP-A-2-97507 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C08F 4/60-4/70

Claims (1)

(57) [Claims] 1. A catalyst comprising the following component (A) and component (B): ethylene or ethylene and ethylene having 3 to 10 carbon atoms.
A process for producing an ethylene polymer, comprising contacting and polymerizing an α-olefin of the formula (1). Component (A) Component (A-2), (A-3),
(A-4) A solid component for a Ziegler catalyst obtained by sequentially contacting (A-5), component (A-1) , the following component (A-1-i), and component (A-1-ii) ) And component (A-1-iii), a component (A-1-i) magnesium dihalide, component (A-1-ii) titanium tetraalkoxide and / or polytitanate, component (A -1-iii) (R ¹ is a hydrocarbon residue) A polymer silicon compound having a structure represented by the following formula: (A-2) a silicon halide, (A-3) an organoaluminum compound, and (A-4) a halogenated carbon. Hydrogen, component (A-5) an organic or halogen compound of aluminum, and component (B) an organoaluminum compound.