KR800000502B1 - Catalysts composition for polymerizing alpha-olefins - Google Patents

Abstract

α-Olefin polymn. catalyst, with good activity, comprised of transition metal compds. and alkylaluminium compd. contg. sterically hindering substituents was described. thus, 14ml triethylaluminium in 25ml heptane was treated with 22g BHT for 2 hr and then heated to 90≰C giving a l M soln. of Et2Al-tert-butyl-p-cresoxy. Mixing 8ml of this soln. and 22.6mg Cl3TiOCH3-MgCl2 catalyst with 1l heptane and polymg. the mixt. at 7 atm H and 6 atm ethylene at 85≰C for 4 hr gave polyetylene with inherent viscosity 1.6 dl/g and a yield of 194,000 g polymer/g Ti.

Description

Polymerization catalyst composition of alpha-olefins

The present invention relates to new components of the polymerization catalysts of alpha-olefins and catalyst compositions prepared therefrom and also to the use of these catalysts in the polymerization or copolymerization of ethylene or alpha-olefins.

It is known to use catalysts obtained from salts of transition metals, organometallic compounds of Groups 1, 2 and 3 elements of the periodic table and especially of aluminum compounds for the polymerization of ethylene or alpha-olefins, and very high yields. In order to polymerize ethylene or alpha-olefins, it is also known that catalysts composed of reaction products of group 1, 2, and 3 elements of the periodic table with organometallic compounds of aluminum or titanium compounds and magnesium compounds are used as catalysts for polymerization.

As organometallic compounds of aluminum used as catalysts for polymerization, halides of aluminum trialkyls and dialkyl aluminums were used. When using aluminum as a catalyst component, a composition in the form of R ₂ AlOR 'or RAl (OR') ₂ is generally used as its organometallic compound, but a catalyst containing a compound such as R ² AlOR 'is very inert. Only very high activity above 100 ℃ shows a very low activity.

In the organometallic compounds of aluminum described above, R 'is methyl, ethyl, propyl or the like or aryl groups such as phenyl. The composition in the form of RAl (OR ') ₂ is also very inert even at high temperatures. It is possible to obtain compounds in the form of R ₂ AlOR '' or RAl (OR '') ₂ by appropriate selection of the R '' group, and these are reacted with transition metals to polymerize olefins, in particular ethylene or alpha olefins. However, it is possible to make a catalyst exhibiting high activity in copolymerization, which exhibits the same activity as the aluminum trialkyls show at temperatures commonly employed in industrial processes.

The R atom group of the R ₂ AlOR '' or RAl (OR '') ₂ compound is an alkyl group having 1 to 12 carbon atoms, and R '' has a structural formula of the following (I) or (II).

Current groups are attached at positions 2 and 6 of formula (I) and positions 2 and 8 of formula (II), at least one of which causes higher steric hindrance than the -C ₂ H ₅ group, The other is methyl, ethyl, propyl or similar alkyl or aryl such as phenyl.

As the group of atoms having higher steric hindrance than the -C ₂ H ₅ group at the aforementioned position, there are generally alkyl atom groups, and branched alkyl atom groups having 3 or more carbon atoms are particularly preferable. Examples of such atomic groups are iC ₃ H ₇ tC ₄ H ₉ , iC ₄ H ₉ , iso-amyl, neopentyl and the like.

In particular, another example of an atomic group having steric hindrance at position 2 or 6 in formula (I) is those having a structural formula as shown in the following formula.

In this formula, R is as described above, and R '''is an atomic group having higher steric hindrance than the -C ₂ H ₅ group.

At positions 3,4 and 5 of formula (I) and positions 3,4,5,6 and 7 of formula (II), atoms or groups which do not react with the aluminum alkyl compound may exist as substituents. Examples of such substituents are halogen atoms, alkyl, aryl, alkylaryl, aralkyl groups.

Especially at the 4 position of Formula (I), a substituent consists of the following groups.

Where R is the same as pointed out above.

R ₂ AlOR '' compounds can be obtained according to well-known methods from AlR ₃ compounds and R''OH, the reaction scheme is as follows.

Such reactions are readily induced with hydrocarbon solvents at or above room temperature. Another R ₂ AlOR '' compound preparation method can be obtained by reacting AlR ₃ with Al (OR '') ₃ according to the following stoichiometry.

This reaction is also carried out at room temperature or higher.

Methods of preparing compounds of type RAl (OR '') ₂ are also known and can be obtained from one of the following reactions.

They also react at room temperature or higher.

As described above, a compound of the form R ₂ AlOR '' or RAl (OR '') ₂ is formed by reaction with a catalyst component constituting the compound of the transition metal, which forms olefins, in particular propylene, butene-1, It is a suitable catalyst for the polymerization of ethylene or alpha-olefins such as 1-methyl-pentene and the like. In the polymerization of propylene, in order to increase the stereospecificity of the catalytic material, the above-mentioned aluminum organometallic compounds of R ₂ AlOR '' and RAl (OR '') type ₂ are particularly in the form as described in Italian Patent No. 932,438. It can be mixed with the electron donor compound of.

Catalysts composed of compounds of transition metals are particularly preferred for halides of titanium (TiCl ₄ , TiBr ₄ , 3TiCl ₃ , AlCl ₃ titanium halo-alcoholates) or titanium alcoholates, vanadium or zirconium halides (VCl ₄ , VOCl ₃ , ZrCl ₄ and the like) and similar compounds. In addition, such a metal compound of the transition element is also used in the form of a complex, which is represented by the following equation.

Where M is Mg, Mn, or Ca

m is a number from 0.5 to 2

M 'is Ti, V or Zr

X is Cl, Br or I

,

그룹Y is a halogen atom or a halogen atom and an oxygen atom -NR ₂ , -OR, -SR,

,

group

(R is a hydrocarbon atom group, in particular alkyl, aryl, cycloalkyl or aralalkyl), anion of acetylacetonate, anion and oxygen atoms of acetylacetonate, and such groups or atoms are present in an amount that satisfies the valence of M '. do.

n is a number from 0.5 m to 20 m.

E is selected from the following compounds as electron donor compounds.

a) esters of organic carboxylic acids,

b) alcohols,

c) esters,

d) amines,

e) esters of carbonyl acid,

f) nitriles,

g) esters of phosphoric acid, phosphorous acid and phosphorus oxychloride,

In the above formula, a part of titanium, vanadium or zirconium may be substituted as aluminum, and the amount thereof is in an atomic ratio of 0.1: 1 to 2: 1 between aluminum and other metals.

The catalyst composition of the present invention can be used as a catalyst component composed of a compound of the transition metal, and in addition to the transition metal, a solid product containing a halogen selected from magnesium, chromium and bromine may be used. It is also characterized by an X-ray spectrum showing halo, and its value is the lattice distance d when chlorine is included in the catalyst composition as the Cl / Mg ratio ≥ in the halo's intensity peak. If it is between 2.43 and 3.20 ms and bromine is included in the catalyst composition as the Br / Mg ratio ≥ 1, the halow is between the distance d 2.80 and 3.25 ms.

Catalyst components, including transition metals, magnesium and halogens (chlorine or bromine) can be obtained by various methods. The best method is to grind the mixture of transition metal and anhydrous chloride or magnesium bromide so that its surface area is 3 m 2 / g or more, and the extinction index of the X-ray spectrum of the ground product of halo falls within the above-mentioned range. Alternatively, the catalysts containing transition metals, magnesium and halogens are MgO, Mg (OH) Cl, magnesium carbonate, MgX (OR), where X is halogen and R is alkyl containing 1-15 carbon atoms. Or an aryl atom group), and the like, and reacted with a halogenated liquid compound of a transition metal. Such reactions can be carried out in the presence of hydrocarbons and the reaction temperature ranges from 20 to 150 ° C. in a polymer. The catalyst component containing the transition metal is selected from the group consisting of a halogen liquid compound of the transition metal MgX ₂ nD (X is chlorine or bromine, D is water or alcohol molecules or ethers, amines, esters, nitriles and the like. It can also be obtained by reacting with a magnesium complex of the same type as the molecule of the electron donor. In this case the reaction is carried out in the presence of excess transition metal compound.

All of the above production methods all use halogen compounds of titanium, vanadium or zirconium selected from halogen alcohols ZrCl ₄ and other analogues of TiCl ₃ , TiCl ₄ , VCl ₄ , VOCl ₃ , VOCl ₃ as compounds of transition metals. do. When using a compound of the form of R ₂ AlOR '' or RAl (OR '') ₂ as a catalyst material for aluminum trialkyls, the superiority is as follows.

1) The compound obtained in the present invention has a lower reactivity with oxygen than aluminum trialkyls, and as a result, unlike aluminum trialkyl, it is not flammable, thus lowering the risk of working.

2) It is a phenolic antioxidant which is adopted to prepare R ₂ AlOR '' or RAl (OR '') ₂ , which is an additive of polymer, which is used in polyolefin production process, after drying process and before drawing process (extrusion, granulation) It is an antioxidant in the form added as an additive. The drawing process closes the contact between the polymer and the additive and effectively exerts its stabilizing activity.

3) It is also a common trend to obtain polymers in the form of spherical particles during polymerization in modern plants for the polymerization process of olefins, which can be used directly by the user, thus costly drawing and pelletizing. The process can be avoided. In this case, however, it is rather difficult to mix the stabilizer very closely with the polymer and it is difficult to obtain satisfactory stability. If a compound of type R ₂ AlOR '' or RAl (OR '') ₂ is used as the organometallic component of the catalyst, at the end of the polymerization process the catalyst is formed by steam or hydrolysis of an aluminum organic metal compound to form a polymer. The R''OH component, which remains in intimate mixture with, loses its activity and thus its stabilizing activity appears effectively.

4) When polymerizing olefins in the gas phase, this process is generally carried out by fluidized bed technique, in which it is absolutely necessary to repeatedly increase the flow rate of olefin through the fluidized bed in order to remove the heat of reaction and improve the supply and fluidity of the monomer. need. It is also necessary to continue to replace the aluminum organometallic compounds contained in the catalyst and having a vapor pressure which is generally negligible at the polymerization temperature, and such compound components are supplied by the gas stream.

Recycling such gases causes the aluminum organometallic compound to accumulate and cause a risk of ignition. The use of organometallic compounds of the form R ₂ AlOR '' or RAl (OR '') in the above-described combination of such compounds is completely free from these drawbacks, which are generally solid and practically negligible. Because it has pressure.

5) Finally, the use of solid organometallic components of aluminum in the form of R ₂ AlOR '' or RAl (OR '') ₂ , when polymerizing olefins in the gaseous state, is generally liquid in the polymerization conditions. The cake of polymer particles resulting from the tackiness caused by the presence of the aluminum alkyl component used as can be prevented.

Polymerization of olefins such as ethylene or alpha-olefins using catalysts prepared according to the process from the compounds of R ₂ AlOR '' or RAl (OR '') ₂ type may be carried out using inert carbohydrate diluents or Or in a liquid or gaseous form, which is not used. The polymerization temperature is usually from 0 ° C to 120 ° C but preferably between 50 ° C and 90 ° C.

In addition, the ratio of aluminum / transition metal is used in a wide range, it is good to use in the range of 5 to 100,000.

Embodiments of the invention are described below, but are not limited in this example.

Example 1

14 mL of triethylaluminum (100 mol of Al (C ₂ H ₅ ) ₃ ) was dissolved in 25 mL of degassed anhydrous n-heptane, and again 22 g of BHT (2,6-ditert butyl-paracresol) 100 m / mol) dropwise over 2 hours. The solution is heated to 90 ° C. until the reaction is complete to obtain a 1 molar solution of (C ₂ H ₅ ) ₂ Al-tert butyl-para-cresoxy [(C ₂ H ₅ ) ₂ Al DBC].

Steel with Cl ₃ TiOCH ₃ and anhydrous magnesium chloride, having a titanium content of 5.3% by weight and showing a spectrum with halo, whose intensity peak appears at a lattice spacing between 2.43-3.20 in X-ray analysis. 22.6 g of the catalyst composition pulverized together under the ball was mixed into 8 ml of the solution containing aluminum, 1,000 ml of anhydrous desulfurized n-heptane was added again, and the mixture was placed in a 3 l capacity autoclave for polymerization of stainless steel, followed by anchor stirrer. The device is heated to 85 ° C. Hydrogen (7 atm) and ethylene (6 atm) are injected until the total pressure is 13 atm, and thereafter, ethylene gas is continuously supplied to maintain this pressure during the polymerization.

After 4 hours, the polymerization was stopped, and the resulting polymer was filtered off and dried to yield 230 g of polyethylene (194,000 g of polymer / titanium g) with an inherent viscosity of 1.6 dl / g.

For comparison, 18 mg of catalyst composition (including titanium and magnesium) and n-heptane of (C ₂ H ₅ ) AlOC ₆ H ₅ as cocatalyst 8 m. The test was repeated using a molar solution where only traces of polyethylene were obtained.

The fact is that the catalyst component in the form of R ₂ AlOR '' is substantially free of substituents because R '' is located at positions 2 and 6 of the phenyl group and has no substituent with higher steric hindrance than -C ₂ H ₅ . Prove that there is no activity.

Example 2

As in Example 1, 24 mg of the catalyst composition was pulverized and dried with an iron ball mill, and reacted with TiCl ₄ and anhydrous MgCl ₂ so that the titanium content was 3.9% by weight. The obtained polyethylene (g number of 420,000 g of polymers / titanium) was 390 g, and the intrinsic viscosity was 1.55 dl / g.

Example 3

Example 2 was repeated starting from a mixed gas of 9 atm ethylene and 4 atm hydrogen using 9.4 mg of catalyst composition.

The resulting polyethylene (g number of 760,000 g of polymer / titanium) was 280 g and the inherent viscosity was 2.55 dl / g.

To compare with this a compound of the form (C ₂ H ₅ ) ₂ AlOR '' was prepared as cocatalyst, where R '' is

1.22 g of 2,6-dimethylphenol (10 m.mol) was dissolved in 20 ml of n-heptane and added dropwise to 1.4 ml of (Al) (C ₂ H ₃ ) ₃ (10 m.mol). It was heated to 80 ° C. until the reaction was complete. The polymerization test described above (Example 3) was repeated, where a 20 mg catalyst composition (including titanium and magnesium) and a solution of the aforementioned R ₂ AlOR '' compound were used, resulting in only 2 g of polyethylene.

To compare with this, a compound of the form (C ₂ H ₅ ) ₂ AlOR '' was prepared as a promoter. Where R '' is

Dilute 1.53 ml (10 m. Mol) of 2-tertiary butyl-phenol in n-heptane to 20 ml and drop it into 1.4 ml of Al (C ₂ H ₅ ) ₃ (10 m. Mol) dropwise. Heat to 80 ° C. until the reaction is complete.

As in the polymerization test in Example 3, 16 mg of the catalyst composition (including titanium and magnesium) and the solution of the R ₂ AlOR '' compound described above were added to repeat the polymerization test to obtain only 3.5 g of polyethylene. .

These two comparative tests were performed at the 2 or 6 position of the R '' atomic group in a compound of the form R ₂ AlOR '',

When there is at least one substitution group with the same or lower steric hindrance than the —C ₂ H ₅ group, it is evident that the catalysts obtained therefrom are actually poor in efficiency.

Example 4

Containing titanium in a ratio of 5% by weight, the spectrum in the X-ray analysis was similar to that of Example 1, and TiCl ₄ -ethylene benzoate and anhydrous MgCl ₂ were carried out in a finely ground 99.4 mg catalyst composition. 6 ml of (C ₂ H ₅ ) ₂ Al (DBC) solution prepared according to Example 1 and 350 ml of desulfurized anhydrous n-heptane were added and placed in a 1,000 ml stainless steel polymerization autoclave, followed by an anchor stirrer. Heat to 60 ° C. and add 0.15 atmospheres of hydrogen in advance. Subsequently, propylene is added until the total pressure reaches 5 atm, and propylene is continuously injected until the pressure is complete. After 2 and a half hours, the polymerization is stopped to give polypropylene, which is washed with methanol and acetone to 435 g (88,000 g of polymer / titanium g). This polymer has an inherent viscosity of 1.67 dl / g and exports to boiling heptane (36 hours as Kumagawa Apparatus) leaving 54.5% residue.

Example 5

6 ml of (C ₂ H ₅ ) Al (DBC) solution prepared as in Example 1 was diluted to 50 ml with n-heptane and 25 ° C. with 162 mg of ethyl p-anisate. The reaction was carried out for 10 minutes at. 105 g of the catalyst composition (containing titanium and magnesium) as in Example 4 and (C ₂ H ₅ ) ₂ Al (DBC) as a promoter were polymerized for 5 hours under the same conditions as in Example 4 Polypropylene (g number of 22,000 g of polymer / titanium) was obtained and its inherent viscosity was 2.13 dl / g and extraction with heptane yielded 89.6% residue.

Example 6

12.6 ml (50 m. Moles) of Al (iso-C ₄ H ₉ ) _{3 in} a solution of 11 g (50 m. Moles) of BHT (2,6 dietary butyl paracresol) dissolved in 60 ml of anhydrous degassed n-heptane. Drop by drop over 2 hours and heat to 90 ° C. until reaction is complete to obtain 0.8 moles of (iso-C ₄ H ₉ ) ₂ Al (DBC).

4 g of catalyst composition (including titanium and magnesium) and 7 ml of (iso-C ₄ H ₉ ) ₂ Al (DBC) compound solution as cocatalyst as in Example 4 were polymerized at 80 ° C. for 5 hours to obtain 61 g. Polypropylene (g number of polymers / titanium of 26,000 g) is obtained, which has an intrinsic viscosity of 1.11 dl / g, and 70.5% of a residue can be obtained by extraction with heptane.

Example 7

Into a 3,000 ml stainless steel autoclave equipped with an anchor stirrer, a fully dried 50 g of polypropylene powder was added, and again, 5 mg of a catalytic composition pulverized with TiCl ₄ and anhydrous MgCl ₂ having a titanium content of 3.9% by weight. 8 m prepared as in Example 1 and diluted to 50 ml with n-heptane. Molar (C ₂ H ₅ ) ₂ Al (DBC) solution is added. After evaporating the solvent by heating to 80 ° C, 0.5 atm of hydrogen and ethylene are placed in an autoclave so that the voltage is 15 atm. In order to keep the pressure constant during the polymerization, the polymerization was stopped after 2 hours of continuous addition of ethylene to obtain 100 g of polyethylene (500,000 g of polymer / titanium g).

Example 8

1.39 mL of Al (C ₂ H ₅ ) ₃ (10 m.mol) was dissolved in 22 mL of anhydrous degassed n-heptane, followed by 27 mL of 1.78 g of 2-tert-butyl-4,6-dimethylphenol. The solution dissolved in n-heptane is dropped dropwise over 1 hour and then heated to 80 ° C. until the reaction is complete.

The solution as the above promoter and 20 mg of the catalyst composition were polymerized in the same manner as in Example 3 to give 98 g of polyethylene (125,000 g of polymer / titanium g).

Example 9

To 20 ml with n-heptane, anhydrous degassed 1.4 ml of Al (C ₂ H ₅ ) ₃ in a solution of 2 g (10 mmol) of 2,6-di-tertiary butyl phenol in 50 ml of n-heptane. Drop into the diluted solution and heat it to 80 ° C. until the reaction is complete. Thus obtained, 240 g of polyethylene (288,000 g of polymer / titanium g) was obtained by repeating the test as described in Example 3 with the solution as a cocatalyst and 21 mg of the catalyst substance composition.

Example 10

20m mole of 2,6-di-tertiary-paracresol was dissolved in 20 ml of anhydrous dehydration n-heptane and it was added to 20 ml of the solution prepared according to the example (containing (C ₂ H ₅ ) ₂ Al DBC). After dropping dropwise, it was diluted again with 100 ml of n-heptane and heated to 90 ° C. until the reaction was completed. The material obtained here is in the form of RAl (OR '') ₂ , in particular RAl (DBC) ₂ , where DBC is tertiary butyl-paracresoxy. 60 g of polyethylene (81,000 g of polymer / titanium g) was subjected to polymerization as described in Example 3 by using the 80 ml solution as the above-described cocatalyst material and adding 19 mg of the catalyst material composition thereto. Got it.

Claims (1)

As described above in the text, as catalyst forming components, at least one Al organometallic compound selected from the group consisting of R ₂ AlOR '' and RAl (OR '') ₂ and the structural formula M _m M'X _2m Y _n E A catalyst composition for polymerizing oligoffins, comprising a complex of transition metals having excitation. In which R is an alkyl group containing 1-12 carbon atoms; R '' corresponds to one of the following structural formulas,

In positions 2 and 6 of structure (I) and optionally in position 8 of structure (II) there are radicals selected from alkyl, aryl and alkylaryl radicals, at least one of which is higher than the steric hindrance of the -C ₂ H ₅ group Indicates steric hindrance; M is Mg, Mn or Ca; m is a number between 0.5-2; M 'is Ti, V or Zr; X is Cl, Br or I; Y is one or more of the same or different atoms or groups, a group consisting of halogen atoms, halogen atoms and oxygen atoms, -NR ₂ , -OR, -SR,

,

Groups and acetylacetonate anion, acetylacetonate anion and oxygen atoms, such groups and atoms being present in an amount that satisfies the valency of M '; n is a number between 0.5m-20m; E is an electron donor compound selected from the group consisting of esters of organic carboxylic acids, alcohols, ethers, amines, esters of carbonic acid, nitriles, and esters of phosphorus oxychloride and phosphoric acid.