JPH0780934B2 - Method for producing olefin polymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing an amorphous olefin polymer, particularly a polymer.

[Prior Art] An amorphous olefin polymer is blended with various resins and used for modifying the properties of the resin, and a high molecular weight one is desired from the viewpoint of physical properties of products.

Conventionally, as a method for producing an olefin polymer, a method using a so-called Ziegler catalyst is widely known, but an amorphous polyolefin produced by a conventionally known Ziegler catalyst, in particular, an atactic polypropylene has an extremely small molecular weight (number average). It was not possible to selectively produce only atactic polypropylene having a molecular weight of about 10,000).

In recent years, as a method for producing a high molecular weight atactic polypropylene, a method using a titanium compound containing a cyclopentadienyl group and a catalyst containing aluminoxane as a main component (JP-A-60-245604) has been proposed. By this method, a relatively high molecular weight atactic polypropylene having a weight average molecular weight (Mw) of about 40,000 can be produced in the room temperature range, but the molecular weight of the atactic polypropylene produced in the industrial practical temperature range (50 to 90 ° C) is There was a problem that it decreased. Further, for applications for resin modifiers, production of atactic polyolefin having a molecular weight of 40,000 or more is desired, but a method for efficiently producing such atactic polyolefin is not known.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for selectively producing an amorphous olefin polymer such as a high molecular weight atactic polypropylene under ordinary polymerization temperature conditions. Is.

[Means for Solving Problems] The present inventors focused their attention on the influence of the polymerization catalyst on the molecular weight of the produced polymer, and conducted extensive research on many catalyst systems to finally produce a polymer having a high molecular weight. The inventors have found a catalyst system that does this and have completed the present invention.

That is, the present invention provides (A) a general formula Ti (OR ¹ ) mX ₄ -m (1) (wherein, R ¹ represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group or an aryl group, X represents a halogen atom, and m is a number satisfying 0 ≦ m ≦ 4), and (B) a general formula MgR ² R ³ (2) (wherein R ² and R ³ are An organomagnesium compound represented by an alkyl group, a cycloalkyl group, an aryl group or an alkoxy group, respectively, and (C) a general formula SiR ⁴ nX ⁴ -n (3) (wherein R ⁴ has 1 carbon atom) The presence of a catalyst obtained from an organosilicon compound represented by the formula: -10 to 10 represents an alkyl group, a cycloalkyl group, an aryl group or an alkoxy group, X represents a halogen atom, and n is a number satisfying 0 ≦ n ≦ 3). Below, olefins characterized by polymerizing α-olefins It is a method for producing a polymer.

Specific examples of the titanium compound of the general formula (1) used as the component (A) of the catalyst used in the present invention include tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium and tetra-titanium.
TiCl _4, TiBr _4, TiI ₄ titanium tetrahalides such as;; n-butoxy titanium, tetraisobutoxy titanium, tetra-cyclohexyl titanium, tetraalkoxy titanium represented by the general formula Ti (OR ¹⁾ _4, such as tetraphenoxy titanium ( CH ₃ O) TiCl ₃ , (C ₂ H ₅ O) TiCl ₃ , (C ₃ H ₇ O) TiCl ₃ , (nC ₄ H ₉ O)
Trihalogenated alkoxy titanium such as TiCl ₃ and (C ₂ H ₅ O) TiBr ₃ ; (CH ₃ O) ₂ TiCl ₂ , (C ₂ H ₅ O) ₂ TiCl ₂ , and (C ₃ H ₇ O) ₂ TiCl ₂ , (NC ₄ H
₉ O) ₂ TiCl ₂ , dihalogenated alkoxy titanium such as (C ₂ H ₅ O) ₂ TiBr ₂ ; (CH ₃ O) ₃ TiCl, (C ₂ H ₅ O) ₃ TiCl, (C ₃ H ₇ O) ₃ TiCl, (nC ₄ H ₉ O)
Examples include monohalogenated alkoxy titanium such as ₃ TiCl.

Among these, tetraalkoxy titanium, especially tetra-
N-butoxy titanium is preferred.

These various titanium compounds may be used alone or in combination of two or more.

The organomagnesium compound used as the component (B) of the catalyst used in the present invention is represented by the above general formula (2),
R ² and R ^{3 in} this formula may be the same or different, and typical compounds are dimethyl magnesium, diethyl magnesium, di-n-propyl magnesium, di-iso-propyl magnesium, di-n-butyl magnesium. , Di-iso-butyl magnesium, di-n-hexyl magnesium, di-n-octyl magnesium, ethyl-n-butyl magnesium, dihexyl magnesium,
Examples include butyloctylmagnesium, dicyclohexylmagnesium, diphenylmagnesium, ditolylmagnesium, ethylmagnesium ethoxide, and butylmagnesium ethoxide.

The silicon compound used as the component (C) of the catalyst used in the present invention is represented by the above general formula (3), and examples of such compounds include SiCl ₄ , CH ₃ SiCl ₃ , and (CH ₃ ) _2. SiC
l ₂ , (CH ₃ ) ₃ SiCl, C ₂ H ₅ SiCl ₃ , (C ₂ H ₅ ) ₂ SiCl ₂ , (C ₂ H ₅ ) ₃ Si
Cl, CH ₃ OSiCl ₃ , (CH ₃ O) ₂ SiCl ₂ , (CH ₃ O) ₃ SiCl, C ₆ H ₅ SiCl
₃ , C ₂ H ₅ OSiCl ₃ , (C ₂ H ₅ O) ₂ SiCl ₂ , (C ₂ H ₅ O) ₃ SiCl, (C ₆ H ₅ )
₂ SiCl ₂ , (C ₆ H ₅ ) ₃ SiCl, (C ₆ H ₅ ) (CH ₃ ) SiCl ₂ , C ₆ H ₁₁ SiC
l ₃ , and (C ₆ H ₁₁ ) (CH ₃ ) SiCl _{2 and the} like.

Each of these components has a molar ratio of component (A) and component (B)
1: 1 to 1: 200, preferably 1: 2 to 1:20, and the molar ratio of component (B) to component (C) is 2: 1 to 1: 100,
It is preferably used in a ratio of 1:10 to 1:90.

In carrying out the olefin polymerization reaction by the production method of the present invention, the above-mentioned catalyst component is added to the reaction system, and then the olefin as a raw material is introduced into this system.

These three components (A), (B) and (C) can be mixed with a predetermined amount and brought into contact with each other, and then olefins can be immediately introduced to initiate polymerization. To obtain it, it is preferable to use it after aging for 0.2 to 3 hours after contact.

In the present invention, the polymerization form and conditions are not particularly limited, and any of solution polymerization, suspension polymerization, gas phase polymerization and the like are possible, and both continuous polymerization and discontinuous polymerization are possible. Particularly, solution continuous polymerization and suspension continuous polymerization are preferable in terms of efficiency and quality.

Moreover, the olefin pressure of the polymerization reaction system of the present invention is 1 to 50 kg.
/ cm ² G, the reaction temperature can be appropriately selected within the range of 20 to 200 ° C, preferably 60 to 100 ° C. The molecular weight at the time of polymerization can be adjusted by a known means such as hydrogen. The reaction time varies depending on the type of olefin as a raw material, but is selected in the range of 1 minute to 2 hours for ethylene and 10 minutes to 10 hours for propylene.

There are various kinds of olefins which can be polymerized by the method of the present invention, for example, linear monoolefins such as ethylene, propylene, butene-1, hexene-1, octene-1 and 4-methyl-pentene-1. Examples thereof include branched monoolefins, diene such as butadiene, and others, and the present invention can be effectively used for homopolymerization thereof or copolymerization of various olefins.

[Effects of the Invention] According to the production method of the present invention, a high molecular weight amorphous olefin polymer can be efficiently obtained. It is useful as an agent.

[Examples] The present invention will be described in more detail with reference to Examples.

Example 1 1 autoclave replaced with argon was charged with n-heptane.
400ml, ethylbutylmagnesium, dimethyldichlorosilane, tetrabutoxytitanium were added in order, and the temperature was 70 ° C.
Then, propylene was supplied and the internal pressure was kept at 8 kg / cm ² to carry out polymerization for 1 hour. The produced polymer was precipitated with methanol, washed, and then vacuum dried. The results are shown in the table.

Examples 2 to 10 and Comparative Examples 1 to 4 The same procedure as in Example 1 was carried out except for the conditions shown in the table. In Examples 3 to 6, since the change in the number of moles of the produced polymer with time is extremely small, it is estimated that the polymer chain has a long life.

Example 11 Tetrabutoxytitanium, ethylbutylmagnesium, and dimethyldichlorosilane were mixed in predetermined amounts in 400 ml of n-heptane, and stirred and aged at 70 ° C. for 2 hours under argon. After depressurizing the argon, propylene was supplied, and Example 1
As a result of the same procedure as above, a homogeneous and tough rubber-like polymer was obtained.

Example 12 Example 12 was repeated except that the amount of dimethyldichlorosilane was doubled and the catalyst aging time was changed to 1 hour.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of the catalyst of the present invention.

Claims (1)

[Claims] (A) General formula Ti (OR ¹ ) mX ₄ -m (In the formula, R ¹ represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group or an aryl group, and X represents a halogen atom. , M is a number satisfying 0 ≦ m ≦ 4), and (B) a general formula MgR ² R ³ (wherein R ² and R ³ are each an alkyl group, a cycloalkyl group, an aryl group, or An alkoxy group), and (C) the general formula SiR ⁴ nX ⁴ -n (wherein R ⁴ represents an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, an aryl group or an alkoxy group). Where X represents a halogen atom, and n is a number satisfying 0 ≦ n ≦ 3), and an olefin polymer characterized by polymerizing an α-olefin in the presence of a catalyst obtained from an organosilicon compound represented by Manufacturing method of coalescence.