JPH0372644B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for modifying a titanium catalyst component,
In particular, when used as a Ziegler-type olefin polymerization catalyst in combination with organometallic compound catalyst components from Groups ~ of the Periodic Table, olefins with high melt tension and swelling ratio suitable for, for example, inflation molding, blow molding, etc. The present invention relates to a method for producing a modified titanium catalyst component that can produce a polymer with good quality reproducibility. More specifically, the present invention combines a highly active titanium catalyst component (A) containing magnesium, titanium and halogen as essential components with an organoaluminum compound (B) obtained from the group consisting of aluminum alkoxyhalide compounds and aryloxyhalide compounds. ) in the coexistence of a titanium catalyst component, which comprises heat treatment at a temperature of about 80 to about 300°C. In the present invention, the term "polymerization" includes not only homopolymerization but also copolymerization, and the term "polymer" is sometimes used to include not only homopolymers but also copolymers. Olefin polymers are molded by various molding methods and are used for a wide variety of purposes. The properties required of the olefin polymer vary depending on the molding method and application. For example, when molding a blown film at high speed, in order to achieve stable high-speed molding without bubble fluctuation or tearing, it is necessary to select an olefin polymer that has a high melt tension relative to its molecular weight. There must be. Similar properties are necessary to prevent sagging and tearing in blow molding, particularly for large containers, or to minimize width loss in T-die molding. Also, when manufacturing large containers with complex shapes by blow molding,
It may be better to select an olefin polymer with a relatively high swelling ratio. In the past, many proposals have been made regarding Ziegler-type catalysts that utilize titanium catalyst components activated with magnesium compounds. Suffice it to say that there are very few proposals to reform it. Slightly JP-A-56-
According to the proposal in No. 90810, a reaction solid containing a halogen-containing titanium compound and an OR group supported on a solid reaction product produced by the reaction of an inert hydrocarbon-soluble organomagnesium component and a halogenating agent is thermally decomposed. substantially manufactured by
It is said that by using a solid catalyst component that does not contain an OR group, it is possible to control the swelling ratio of the olefin polymer over a wide range. Also, JP-A-56
No.-90809 proposes a method in which the use of a halogenating agent is omitted from the above proposal.
However, although solid catalyst components obtained by such thermal decomposition methods show improvements in swelling ratio etc. compared to those before thermal decomposition, they still have the problem of a non-negligible decrease in catalyst activity. be. The present inventors have conducted research to develop a method that can overcome the above-mentioned troubles. As a result, the highly active titanium catalyst component (A) was heated at a temperature of about 80 to about 300°C in the coexistence of an organoaluminum compound (B) selected from the group consisting of aluminum alkoxyhalide compounds and aryloxyhalide compounds. An improved modification that suppresses the decrease in the activity of the titanium catalyst component by heat treatment, and can produce an olefin polymer with high melt tension and swelling ratio without a substantial decrease in activity. It has been discovered that titanium catalyst components can be provided. Raw material titanium catalyst component (A) used for reforming of the present invention
is a highly active component that essentially includes magnesium, titanium, and halogen, and preferably further contains an alkoxy group or an aryloxy group. Examples of such catalyst components (A) include halogen/titanium (atomic ratio) of about 5 to about 100, preferably about 6 to about 50, and magnesium/titanium (atomic ratio) of about 1 to about 100. , preferably from about 2 to about 80, more preferably from about 2 to about 40, alkoxy or aryloxy group/titanium (molar ratio) from 0 to about 10, preferably from about 0.2 to about 7, more preferably from about 0.3 to 5, and generally contains amorphous magnesium dihalide and has a surface area of about 40 m ² /g or more, particularly about 80 to about 800 m ² /g. . It may also optionally contain other functional groups or elements. Such a raw titanium catalyst component can be obtained by mutual reaction of a magnesium compound, a titanium compound, and optionally an auxiliary reaction agent. In this case, at least one of the components forming the raw titanium catalyst component contains a halogen, and preferably has an alkoxy and/or aryloxy group, or Alkoxy- and/or aryloxy-forming components capable of forming groups, such as alcohols and/or phenols, may be used. Magnesium compounds that can be used for this purpose include OR groups and/or
There are compounds containing an R'OH group (R and R' are substituted or unsubstituted alkyl groups, cycloalkyl groups, or aryl groups). That is, examples include compounds having an alkoxy group and/or an aryloxy group, or alcohol and/or OH-containing aryl compounds, such as phenol complexes. Such magnesium compounds may further contain other elements or metals, or may contain other groups. A representative example of such a magnesium compound is the following formula Mg(OR) _o X _2-o・mR′OH (wherein R and R′ are the same as above,
0≦n≦2, 0≦m) can be exemplified. R and R' are methyl, ethyl, n-propyl, iso-butyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-decyl , n-dodecyl, n-tetradecyl, n-octadecyl, oleyl, hydroxyethyl, methoxyethyl, n-butoxyethyl, etc. _C1 - _C20
aliphatic hydrocarbon groups of _C5 to _C15 such as cyclopentyl, cyclohexyl, methylcyclohexyl; phenyl, tolyl, xylyl, naphthyl, chlorophenyl, methoxyphenyl, ethyl phenyl, di-tert-butylphenyl, _C6 such as benzyl, isopropylbenzyl
~ _C15 aromatic hydrocarbon group; etc. can be exemplified. These groups may be substituted with halogen, silicon compound, phosphorus, or the like. Also, X is
Selected from fluorine, chlorine, bromine, and iodine. Among these, particularly preferred are those where x is chlorine, 0≦n≦1.5, and 0.5<m<10. Examples of titanium compounds that can be used to prepare the raw material titanium catalyst component include the following formula Ti(OR'') _l X _4-l (wherein R'' is a hydrocarbon group, X is a halogen,
A tetravalent titanium compound represented by ≦l≦4) can be exemplified. In the above formula, specific examples of R″ include R,
As R', the same ones as those exemplified above can be mentioned. When producing a raw titanium catalyst component by reacting a magnesium compound and a titanium compound, if the magnesium compound is solid, it can be suspended in a liquid titanium compound (which may be diluted with an inert hydrocarbon). It is possible to cause a reaction. Alternatively, the magnesium compound and the titanium compound can be reacted by mechanical co-milling. Furthermore, when the magnesium compound is in a liquid state dissolved in an inert hydrocarbon, the reaction can be carried out by mixing it with a liquid titanium compound. The amount of the titanium compound to be used can be selected as appropriate depending on the reaction mode, but for methods other than mechanical grinding, it is about 0.01 to about 100 mol, particularly about 1 to about 100 mol, per 1 mol of the magnesium compound. is preferable. Even smaller amounts may be used in the mechanical grinding method. Further, the recommended reaction temperature is, for example, about 10 to about 180°C, more preferably about 20 to about 140°C. The raw titanium catalyst component can also be obtained by mutually reacting a magnesium compound and a titanium compound with other auxiliary reaction reagents. Examples of such auxiliary reaction reagents include compounds that can react with alkoxy groups and/or aryloxy groups present in the catalyst preparation system, or alcohols and/or OH-containing aryl compounds such as phenols. For example, organoaluminum compounds, such as those exemplified as organoaluminum compounds that can be used in olefin polymerization as described later; silicon halides, such as silicon tetrahalides, silicon alkyl halides, silicon alkoxy halides; others, tin, phosphorus; , halogen compounds such as sulfur; halogen; hydrogen halide; and the like. In the mutual reaction between a magnesium compound, a titanium compound, and an auxiliary reaction reagent, there is a method in which the magnesium compound is reacted with the auxiliary reaction reagent, and then the titanium compound is reacted; after the magnesium compound is reacted with the titanium compound, the auxiliary reaction reagent is reacted. A method of simultaneously reacting a titanium compound and an auxiliary reaction reagent with a magnesium compound; or a combination method of these methods can be employed. Even in the reaction using an auxiliary reaction reagent, a method similar to the reaction pattern between a magnesium compound and a titanium compound can be adopted. In any case, there are many proposals for methods for producing these titanium catalyst components, which are already known and can be used to produce the raw material titanium catalyst component used to form the modified titanium catalyst component of the present invention. In the present invention, the above-mentioned highly active titanium catalyst component
(A) is heat-treated in the coexistence of at least one organoaluminum compound (B) selected from the group consisting of aluminum alkoxyhalide compounds and aryloxyhalide compounds. The component (B) may be any compound as long as it contains an alkoxy group or an aryloxy group and a halogen, but a typical one is a compound having the general formula M(OR) _p X _qp (where M
is aluminum, R is a hydrocarbon group, q is the valence of M, and 0<p<q). As an example of R,
Examples include aliphatic, alicyclic, or aromatic hydrocarbon groups similar to those exemplified for the magnesium compound. Alternatively, it may be a complex of the compounds represented by these formulas, such as a complex with an electron donor or other compound. More specifically, Al(OR)
_o X _3-o , (where R is a hydrocarbon group, X is a halogen,
A compound represented by a formula such as 0<n<3, etc. can be exemplified. Examples of compounds represented by these formulas include Al(O iso-C ₃ H ₇ ) ₂ Cl, Al(O
iso- _C4H9 ) _Cl2 , Al ₍ Osec _{- C4H9} ) _Cl2 , Al
(O tert-C ₄ H ₉ ) Cl ₂ , Al (O iso-C ₃ H ₇ )
Br ₂ , Al(O n-C ₅ H ₁₁ )Cl ₂ , Al(O iso-
_C6H13 ) _Cl2 , Al(O n- _C12H25 ) _{Cl2 , Al} (O
iso-C ₃ H ₇ ) _1.5 Cl _1.5 , Al(O iso-C ₃ H ₇ ) ₂ Cl,

【formula】 [Synthesis of Ti catalyst component]

5g of commercially available anhydrous magnesium chloride was mixed with n-decane.
Suspend in 200 ml of ethanol while stirring.
After dropping 14.5 g over 1 hour, the mixture was further stirred for 1 hour. Next, diethyl aluminum chloride
15.8g was added dropwise at room temperature and stirred at 40°C for 1 hour. After adding 100ml of titanium tetrachloride into the system, the temperature was raised to 80
Stirred at ℃ for 2 hours. The supernatant was washed with fresh n-decane by decantation to obtain a Ti-containing catalyst component (A). Component (A) is titanium 5.2% by weight, chlorine
64wt%, magnesium 16wt%, aluminum
Contains 2.1wt% and 9.7wt% ethoxy groups. The specific surface area is
It was 265m ² /g. 5 g of Ti-containing component (A) was suspended in 150 ml of n-decane, and after adding 0.85 g of dichloromonoisopropoxyaluminum with an average composition, the temperature was raised and stirred at 130°C for 3 hours. A Ti-containing solid catalyst component (C) was obtained by filtering and washing. According to analysis, the composition of component (C) is titanium 4.5wt%, chlorine 61wt%, magnesium 16wt%,
Aluminum 5.1wt%, isopropoxy group 3.3wt%
It was hot. [Polymerization] After thoroughly purging a stainless steel autoclave with an internal volume of 2 with nitrogen, add n-hexane from 1.
The temperature was raised to 50°C. Next, add 1.0 mmol of triisobutylaluminum and 0.02 mg of the above component (C) in terms of Ti atoms, and after sealing, add hydrogen until the gauge pressure becomes 4.0 Kg/cm ² , and then add ethylene and gauge The pressure was 8.0Kg/cm ² . Total pressure is 8
The temperature was maintained at 80° C. for 2 hours while continuously supplying ethylene to maintain the temperature of kg/cm ² -G. The obtained polyethylene was 296 g, MI was 1.21 g/10′, melt tension (MT) was 7.3 g, die swell (SR)
The ratio was 67%. Comparative Example 1 [Polymerization] Polymerization was carried out using the Ti catalyst (A) of Example 1 under the polymerization conditions of Example 1. The obtained polyethylene
The weight was 406 g, the MI was 4.4 g/10', the melt tension was 1.5 g, and the die swell ratio was 42%, which were lower than the MT and SR values obtained in Example 1. Examples 2 to 8 Ti catalysts were prepared in the same manner as in Example 1, except that the type, amount, and treatment conditions of the alkoxy-containing Al compound were changed as shown in Table 1. Example 1
Polymerization was carried out by changing the conditions as shown in Table 1. The results are shown in Table 1.

【table】

[Synthesis of Ti catalyst component]

19.1g of commercially available magnesium chloride was mixed with n-decane.
After suspending in 88.4ml 2-ethylhexanol
78.1 g was added to the system, and the system was heated and stirred at 135°C for 4 hours to obtain a homogeneous transparent liquid. After 4 hours, the temperature of the system was lowered and 9.58 g of orthotetraethoxysilane was added at 100°C, and the mixture was stirred at 100°C for 1 hour to obtain a magnesium chloride-containing n-decane solution. After charging 200 ml of titanium tetrachloride into a 200 ml flask and lowering the temperature to -20°C, the magnesium chloride-containing n-
50 ml of decane solution (magnesium chloride concentration 1 mol/
) was added dropwise over 2 hours. Gradually raise the temperature of the system to 90
After stirring for 2 hours at °C, the mixture was heated, washed with hot n-decane, and the solid portion was thoroughly washed with n-decane. The solid part is 10.7% by weight of titanium and chlorine on an atomic basis.
57.0% by weight, magnesium 12.0% by weight,

[Polymerization]

Under the polymerization conditions of Example 1, the hydrogen partial pressure was set to 5
Polymerization was carried out under the same conditions as in Example 1 except that the amount was changed to Kg/cm ² . Yield of polyethylene is 249.6g, MI is
The powder had an apparent specific gravity of 1.90g/10′, 12g for MT, 111% for SR, and 0.32g/ml. The powder had a D50 of 310μ and a geometric standard deviation of 1.2. Example 10 [Polymerization] A stainless steel autoclave with an internal volume of 2 was sufficiently purged with nitrogen, and then n-hexane from 1 was added.
The temperature was raised to 50°C. Next, 1.0 mmol of triisobutylaluminum and 0.02 mg of the Ti catalyst component of Example 9 in terms of Ti atoms were added, and after sealing, hydrogen was added until the gauge pressure reached 2 Kg/cm ² and further mixed. Gas (98.3 mol % ethylene, 11.7 mol % butene) was added to bring the total pressure to 5 Kg/cm ² -G. The temperature was maintained at 80° C. for 2.5 hours while continuously supplying ethylene to maintain the total pressure at 5 kg/cm ² -G.
The amount of polyethylene obtained was 154 g. MI of polyethylene is 2.05g/10', apparent specific gravity is 0.29
g/ml, melt tension is 11.0g, SR is 116.9
It was %. Comparative Examples 2 to 5 [Synthesis of Ti catalyst component] Synthesis of Ti catalyst component in Example 1 was performed in the same manner as in Example 1, except that 0.85 g of dichloroisopropoxyaluminum and heat treatment conditions were changed as shown in Table 2. did. [Polymerization] An experiment was carried out in the same manner as in Example 1 except that the materials were changed as shown in Table 2. The results are shown in Table 2.

【table】

[Synthesis of Ti catalyst component]

In a nitrogen stream, 1 mol of commercially available metallic magnesium was added to 500 ml of dehydrated and purified hexane, and 1.1 mol of tetraethoxysilane was further added, and the mixture was heated to 65° C. with stirring. After raising the temperature, a small amount of methyl iodide and iodine were added dropwise, and then 1.2 mol of n-butyl chloride was added dropwise over 2 hours, followed by stirring at 70°C for 3 hours.
After the reaction was completed, the solid portion was collected by filtration, and the solid portion was repeatedly washed with hexane. 10 g of the solid was suspended in 100 ml of titanium tetrachloride and stirred at 130°C for 2 hours. After removing the supernatant by decantation, another 100 ml of titanium tetrachloride was added and stirred at 130°C for 1 hour. The produced solid portion was collected by heating, and the solid portion was thoroughly washed with hot n-decane and room temperature decane. The solid produced is 6.3% by weight of titanium and chlorine.
64.0% by weight, 19.0% by weight of magnesium, and 3.6% by weight of ethoxy groups. 5g of produced solid is converted into n-decane
Suspended in 200ml.

[Polymerization]

Polymerization was carried out under the conditions of Example 1. The yield of the obtained polymer was 192 g, the MI of the polymer was 1.5 g/10′,
[η] is 1.72dl/g, apparent specific gravity is 0.29g/ml,
MT was 12.6g and SR was 108.2%. Comparative Example 6 [Synthesis of Ti catalyst component] 5 g of Ti catalyst component (A) of Example 9 was mixed with 200 g of n-decane.
ml and treated at 160°C for 3 hours. The solid portion was collected by heating and washed thoroughly with fresh hexane. The solid part according to the analysis is 8.9% by weight of titanium, 43.0% by weight of chlorine, 14.0% by weight of magnesium,

[Polymerization]

Polymerization was carried out under the polymerization conditions of Example 9. The yield of polyethylene was 148.2g, the apparent specific gravity was 0.32g/ml,
MI was 1.20g/10′, MT was 6.9g, and SR was 73%.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the steps for preparing a catalyst using the titanium catalyst component of the present invention.

Claims (1)

[Claims] 1. A highly active titanium catalyst component (A) containing magnesium, titanium, and halogen as essential components, and an organoaluminum compound (B) selected from the group consisting of aluminum alkoxyhalide compounds and aryloxyhalide compounds. A method for modifying a titanium catalyst component, characterized by heat treatment at a temperature of 80 to 300°C in the coexistence of. 2. The method according to claim 1, wherein the highly active titanium catalyst component (A) further contains an alkoxy group or an aryloxy group. 3. The method according to claim 1, wherein the alkoxy group of the aluminum alkoxy halide compound is an alkoxy group having a branched alkoxy group or a cyclic group.