JPS636006A - Production of linear low-density polyethylene - Google Patents

Abstract

PURPOSE:To produce the title PE excellent in mechanical properties, moldability, transparency, etc., in high polymer yields, by copolymerizing ethylene with a 3-4C alpha-olefin and a 6-12C alpha-olefin in the presence of a specified catalyst. CONSTITUTION:A catalyst is obtained either by reacting a reaction product of an Mg carboxylate (A) of formula I [wherein R<2> is a 1-30C (cyclo)alkyl, aryl or aralkyl] with an organoaluminum compound (B) of formula II [wherein R<3> is a 1-10C (cyclo)alkyl or aryl, X is a halogen and n<=3] with a Ti compound (C) of formula III [wherein R1 is a 1-10C (cyclo)alkyl, aryl or aralkyl and 0<=m<=4] or by reacting a reaction product of component A with component C with a component B. 90-99mol% ethylene is copolymerized with 0.4-9.5mol% 3-4C alpha-olefin and 0.4-9.5mol% 6-12C alpha-olefin at 50-300 deg.C and a pressure of 150kg/cm<2>.G in the presence of said catalyst to obtain a linear low-density PE of a density of 0.90-0.940g/cm<3>.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to the use of ethylene, an α-olefin having 3 to 4 carbon atoms, such as propylene, butene-1, etc., and an α-olefin having 6 to 12 carbon atoms, such as octene-1. For more details, please refer to the mechanical properties, moldability,
The present invention relates to a method for producing linear low-density polyethylene that can produce a polymer with excellent transparency and the like in a high polymer yield in the presence of a catalyst with high monopolymerization activity.

[Prior art and its problems] Conventionally, as a method for producing copolymers of ethylene and other α-olefins, high-temperature solution polymerization is carried out in the presence of a catalyst obtained from an organomagnesium compound, a titanium compound, and an organoaluminium compound. (Unexamined Japanese Patent Publication No. 50-391)
17, JP-A-5O-42405, etc.) are known.

However, these conventionally known methods have problems in that the catalytic activity and catalytic activity sustainability are insufficient, and the physical properties of the obtained polymers are still unsatisfactory.

[Purpose of the invention] This invention has been made based on the above circumstances.

That is, an object of the present invention is to provide a method for producing linear low-density polyethylene that has excellent properties such as mechanical properties, moldability, and transparency by increasing catalytic activity and catalytic activity sustainability. be.

[Means for Solving the Problems] In order to achieve the above-mentioned object, as a result of intensive research by this inventor, a magnesium carboxylate, an organoaluminum compound, and a titanium compound are brought into contact and reacted in a specific order. The resulting catalyst has high activity and excellent durability of activity, and can be used to produce ethylene, an α-olefin having 3 to 4 carbon atoms, and an α-olefin having 6 to 12 carbon atoms.
The present invention was achieved by discovering that when polymerized with olefin, the yield of the polymer is high, and the polymer has excellent properties such as mechanical properties, moldability, and transparency.

That is, the gist of the present invention for achieving the above object is to provide a catalyst obtained from a reaction product of a magnesium carboxylate and an organoaluminum compound and a titanium compound, or a reaction between a magnesium carboxylate and a titanium compound. A linear low density polyethylene characterized by polymerizing ethylene, an α-olefin having 3 to 4 carbon atoms, and an α-olefin having 6 to 12 carbon atoms in the presence of a catalyst obtained from a product and an organoaluminum compound. This is the manufacturing method.

The magnesium carboxylate [hereinafter referred to as (A)]
Sometimes abbreviated as component. ] can be represented by the general formula % (wherein R2 represents an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group having 30 carbon atoms).

In the method of the present invention, magnesium carboxylates are preferably magnesium aliphatic carboxylates and magnesium aromatic carboxylates.

Specific examples of the aliphatic carboxylic acids constituting the aliphatic carboxylate of magnesium include monocarboxylic acids such as acetic acid, propionic acid, palmitic acid, and stearic acid, dicarboxylic acids such as succinic acid and adipic acid, pyruvic acid, Examples include ketocarboxylic acids such as levulinic acid, and unsaturated carboxylic acids such as linoleic acid and lylunic acid.

Specific examples of the aromatic carboxylic acids constituting the aromatic carboxylate of magnesium include benzoic acid and alkyl-substituted benzoic acids such as toluic acid, ethylbenzoic acid, isopropylbenzoic acid, dimethylbenzoic acid, and trimethylbenzoic acid; Halogen-substituted benzoic acids such as fluorobenzoic acid, chlorobenzoic acid, bromobenzoic acid, iodobenzoic acid, dichlorobenzoic acid, dibromobenzoic acid, alkoxy or acyloxybenzoic acids such as anisic acid, phenoxybenzoic acid, acetoxybenzoic acid, phthalic acid , aromatic dicarboxylic acids such as chlorophthalic acid and dichlorophthalic acid, and naphthalenecarboxylic acid.

Examples include polycyclic aromatic carboxylic acids such as anthracenecarboxylic acid, and carboxylic acids containing aromatic rings such as phenylacetic acid.

Among the various magnesium salts of carboxylic acids, preferred are stearate, toluate, and benzoate, and particularly preferred are stearate and toluate.

The organoaluminum compound [Hereinafter, this organoaluminum compound may be abbreviated as component (B). ]teeth,
- General formula formula % (However, R3 in formula 1 has a carbon number of 1 to 1O1, preferably 1
~6 alkyl group, cycloalkyl group or aryl group, X represents a halogen atom, n is a positive number of 3 or less, specifically 1.1.5.2 or 3,
In particular, it is preferably 2 or less.

Specific examples of component (B) include trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum monochloride, diethylaluminum monopromide, diethylaluminium monoiodide, diisopropylaluminum. Dialkyl aluminum monohalides such as dialkyl aluminum monohalides such as monochloride, diisobutyl aluminum monochloride and dioctyl aluminum monochloride, or alkyl aluminum sesquihalides such as methyl aluminum sesquichloride, ethyl aluminum sesquipromide and butyl aluminum sesquichloride are suitable. , and mixtures thereof are also suitable.

The titanium compound [Hereinafter, this titanium compound may be abbreviated as component (C). ] is - general formula % (wherein, R1 has 1 to 10 carbon atoms, preferably 1
~6 alkyl group, cycloalkyl group, 7-aryl group, or aralkyl group, or the same halogen atom as above, and m is an integer of 0, 1, 2°3, but is not necessarily an integer. First, it is a real number that satisfies O≦m≦4 as an average value of a mixture of various titanium compounds. ) can be shown.

Component (C) specifically includes, for example, tetramethoxytitanium, tetraethoxytitanium, tetra-n
- Tetraalkoxytitanium represented by the general formula Ti(ORI)a such as propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, tetracyclohexoxytitanium, tetraphenoxytitanium; TiC1n, TiBra, T
Tetrahalogenated titanium represented by the general formula T i X s such as iIa; (CH30)TiC13, (C2H
s 0) TtCuz, (Cx R70) TiCl13,
(n-C4R9)TiCl3, (C2R50)Ti
Trihalogenated alkoxytitanium such as Br3; (CHI
O) 2 T i C also 2, (C2Hs 0)
2TiCuz, (C31(70) 2TiCl2,
(n-C4Hq O)2 Ti C12, (C2H
s O) dihalogenated titanium such as 2TiC1z, (C
R30)3TicjL, (C2R50)3Ti
C1, (C3H+ O)3 TLCI, (n-Cs R
90) Monohalogenated titanium such as 3T i C1 and the like can be mentioned. Among these, the formula Ti(OR
I) Tetraalkoxytitanium and Ti represented by 4
Tetrahalogenated titanium represented by X5 is preferred,
Particularly preferred are tetra-n-butoxytitanium and tetrachlorotitanium.

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

The catalyst in this invention comprises the component (A) and the component (B).
The components and the component (C) are brought into contact in a specific order.

Obtained by reaction.

That is, first, the order in which the reaction product obtained by reacting component # (A) and the component (B) and the component (C) is contacted, or the component (A) and the component (C) are brought into contact with each other. It is important that the catalyst be obtained by any method in which the reaction product obtained by reacting the components with the component (B) is brought into contact with each other.

Even if the reaction product obtained by first contacting the component (B) with the component (C) is brought into contact with the component (A) I&, the object of the present invention cannot be achieved.

However, satisfying the contact order of the components (A) to (C) may mean eight components, for example, the component (A) and the component (B).
It is not preferable to add the component (C) immediately after adding the above components, since a highly active catalyst may not be produced. Therefore, the component (A) and the component (B)
) A maturing period is provided between mixing the above components and adding the (C) component or after mixing the above (^) component and the above (C) component until adding the above (B) component. is preferable.

This ripening period may normally be at least 30 minutes, preferably at least 60 minutes.

The contact reaction between the component (A) I& and the component (B) or component (C) can be carried out by adding these components to an inert solvent, for example, at a temperature of 0 to 240° C. during the aging period.

Examples of the inert solvent include aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons having 5 to 1 B carbon atoms, and specific examples include normal- or in-pentane, hexane, heptane, and octane. , nonane, decane, tetradecane or cyclohexane, as well as benzene, toluene, xylene and the like. Moreover, the above-mentioned various hydrocarbons can be used alone as this inert solvent. Preferred inert solvents include, for example, isoparaffinic mixed solvents.

It is commercially available under the trade name "rIP Solvent".

The proportions of component (A), component (B) and component (C) are usually as follows.

That is, the molar ratio of component (A)/component (C) is 0.
．． 1 to 200, preferably 0.1 to 30,
Particularly preferably 0.5 to 20.

Further, the molar ratio of component (B)/component (C) is 1 to
200, preferably 2-100, particularly preferably 4-50.

If the ratio of each of the components is out of the range, the catalyst activity may decrease.

In addition, during the polymerization, the component (B) may be further added to the catalyst prepared as described above, if necessary.
When the component (B) is added, it acts as a co-catalyst, thereby further improving the catalytic activity.

The amount of this newly added component (B) is desirably 1 to 300, preferably 5 to 100, in terms of the molar ratio of aluminum atoms in component (B) to titanium atoms in the catalyst.

According to the method of the present invention, ethylene, an α-olefin having 3 to 4 carbon atoms, and an α-olefin having 6 to 12 carbon atoms are combined in the presence of the catalyst and the component (B) newly added as necessary. copolymerization proceeds.

Examples of the α-olefin having 3 to 4 carbon atoms include propylene and 1-butene. In this invention, one or both of butene and propylene are simultaneously used.
can be used.

As the α-olefin having 6 to 12 carbon atoms.

For example, hexene-1, heptene-1, octene-1
, nonene-1, decene-1, etc., linear monoolefins, 4
Branched 7-olefins such as -methyl-pentene-1,3-methyl-pentene-1, and further styrene are included. Among these, the linear monoolefins mentioned above are particularly preferred.

Preferred combinations of raw materials used in the reaction of this invention are ethylene, propylene and 1-octene, and ethylene, 1-butene and 1-octene, particularly preferably ethylene, 1-butene and 1-octene. be.

When copolymerizing ethylene, the propylene and/or butene-1, and the α-olefin, (the ethylene unit content of the linear low density polyethylene to be obtained is 90
~88 mol%, propylene unit content or butene-1
Unit content is 0.4 to 3.5 mol%, preferably 0.5
~5 mol%, the α-olefin unit content is ~0.4
When the raw material monomer mixture is supplied at a concentration of 9.5 mol%, preferably 0.5 to 5 mol%, the density is 0.91Q.
~0.940g/Cm', especially 0.910-0.938
G/C linear low density polyethylene can be suitably produced.

The conditions for polymerization in this invention cannot be generalized depending on the physical properties of the desired polymer, the type of hexamer, etc., but usually the catalyst concentration is 0.001-1 in terms of titanium concentration.
The reaction temperature is 50 to 300°C, preferably 150 to 250°C, that is, the temperature at which the produced polymer dissolves, and the reaction pressure is 150 k. g/cm'G
Below, it is preferably 5 to 90 kg/cG. The polymerization reaction may be carried out in the presence or absence of an inert solvent, and a molecular weight regulator such as hydrogen may also be present in the polymerization reaction system.
Examples include the aforementioned aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons.

[Effects of the invention] (1) Since a catalyst is used that is capable of contacting and reacting a magnesium carboxylic salt, an organoaluminium compound, and a titanium compound in a specific order, the catalytic activity is high and the activity is long-lasting. As a result, the yield of one polymer can be increased.

(2) Furthermore, if ethylene, propylene and/or butene-1 are copolymerized with the above α-olefin in the presence of this catalyst, the copolymerizability can be increased, and therefore, the copolymerization property can be increased. The amount of propylene and/or butene and the α-olefin to be used can be minimized, and wasteful use of α-olefin can be prevented, which is economical, and (3) by the method of the present invention. The resulting polymer has excellent mechanical properties such as impact resistance, moldability, transparency, etc.

It is possible to provide a method for producing linear low-density polyethylene that has various excellent advantages such as.

[Examples] Next, the present invention will be explained in more detail by showing examples and comparative examples of the present invention.

(Example 1) ■Titanium-containing reaction product Dehydrated IP turbene in a 9500mM flask substituted with argon) 2028 [Idemitsu Petrochemical Co., Ltd.]
5.9 g of magnesium stearate (
10 mmol) and kept at 5°C. After 2.4 g (20 mmol) of diethylaluminium chloride was gradually added dropwise thereto and reacted for 20 minutes, the temperature was further raised to 40° C. and reacted for 3 hours.

Next, cool to room temperature, titanium tetrachloride 0.19g (1,
0 mmol) was added thereto, the temperature was raised, and the reaction was carried out at 100° C. for 3 hours to obtain the entire amount of the reaction product as a titanium-containing reaction product.

■Production of ethylene-butene-1-octene-1 copolymer Contents of substitution with argon'tIi1! In a L autoclave, put 500 mJl of dehydrated IP solvent, 20 g of butene-1 and 40 g of octene-1.

The temperature was raised to 185°C. From the catalyst input tube connected to the upper part of this autoclave, 50rnl of IP solvent, 8ml (2 mmol) of IF solvent of ethylaluminum sesquichloride, and the titanium-containing reaction product obtained in step After adding it in an amount of 0.05 mmol and pressurizing it into an autoclave, ethylene was injected so that the ethylene partial pressure was 10 kg/crn' to start polymerization. Ethylene was continuously supplied so as to maintain the ethylene partial pressure, and the polymerization reaction was carried out for 10 minutes to obtain an ethylene copolymer. The results are shown in Table 1. In Table 1, MX is the melting index and MFR is the melt flow ratio (flow rate/melting index). As an ethylene copolymer, this MFR is usually 18 to 52, especially 23. A value of 42 to 42 provides excellent impact resistance, a value less than 18 results in poor moldability, and a value greater than 52 results in poor transparency.

(Example 2) ■Preparation of a titanium-containing reaction product A titanium-containing reaction product was prepared in the same manner as in Example 1■ above, except that titanium tetrachloride was replaced with tetra-n-butoxytitanium. Obtained.

■Production of ethylene-propylene-octene-1 copolymer In the above-mentioned Example 1■, butene-1 was replaced with propylene, and this propylene and the titanium-containing reaction product obtained in the above-mentioned Step 2 were used. It was carried out in the same manner as in 1■.

The results are shown in Table 1.

(Example 3) Example 1 except that magnesium stearate was used in place of magnesium stearate in Example 1■.
A titanium-containing reaction product was obtained in the same manner as in 1. Using this titanium-containing reaction product, the same procedure as in Example 1 (2) above was carried out.

(Example 4) ■ Preparation of titanium-containing reaction product A titanium-containing reaction product was obtained in the same manner as in Example 3 except that titanium tetrachloride was used in place of tetra-n-butoxytitanium. Ta.

■Production of ethylene-hexene-1-butene-1 co-m combination In Example 1■, hexene-1 was replaced with octene-1.
The same procedure as in Example 1 (2) was carried out using this and the titanium-containing reaction product obtained in (1) above.

The results are shown in Table 1.

(Example 5) Using the same titanium-containing reaction product as in Example 4■,
This and the organoaluminum compound shown in Table 1 were used, and the same procedure as in Example 4■ was used except that propylene was used instead of butene-1 in Example 4■. - A propylene copolymer was obtained.

The results are shown in Table 1.

(Example 6) ■ Preparation of titanium-containing reaction product Contents Into a 500 ml flask purged with argon, 200 mJl of dehydrated IP Solvent 202B, 5.9 g (10 mmol) of magnesium stearate, and 0.19 g of titanium tetrachloride. (1.0 mmol) was added, the temperature was raised, and the reaction was carried out at 100° C. for 3 hours to obtain the entire amount of the reaction product as a titanium-containing reaction product.

■Production of ethylene-octene-1-butene-1 copolymer Into an argon-filled autoclave with an inner volume of 11, 500 mJl of dehydrated IP Nluvent, 35 g of octene-1, and 25 g of butene-1 were placed and heated to 185°C. The temperature rose. Ethylene was continuously supplied into this so that the ethylene partial pressure was 10 kg/am'. Furthermore, 2.4 mmol of diethylaluminum chloride and the titanium-containing reaction product obtained in the above ① were converted into titanium atoms to give 0.
The polymerization reaction was carried out for 10 minutes and ethylene-octene-1-butene-
One ffi combination was obtained.

The results are shown in Table 1.

(Example 7) In place of magnesium stearate in Example 6■,
- Example 6 above except that magnesium toluate is used.
A titanium-containing reaction product was obtained in the same manner as in (1), and the same procedure as in Example 6 (2) was carried out, except that this titanium-containing reaction product and the organoaluminum compounds of the types shown in Table 1 were used.

The results are shown in Table 1.

(Example 8) ■Preparation of a titanium-containing reaction product A titanium-containing reaction product was prepared in the same manner as in Example 6■ above, except that titanium tetrachloride was replaced with tetra-n-butoxytitanium. Obtained.

■Production of ethylene-decene-1-butene-1 co-i complex In Example 6■ above, decene-1 was used instead of octene-1, and this and the titanium-containing reaction product obtained above were used to produce ethylene. -Decene-1-butene-1 copolymer was obtained.

The results are shown in Table 1.

(Example 9.10) A titanium-containing reaction product was obtained in the same manner as in Example 6■ except that the magnesium carboxylate and titanium compound shown in Table 1 were used. 1st
The same procedure as in Example 6 (2) was carried out except that the types of organoaluminum compounds shown in the table were used.

The results are shown in Table 1.

(Example 11) ■ Preparation of a titanium-containing reaction product A titanium-containing reaction product was prepared in the same manner as in Example 8■ above, except that magnesium benzoate was used in place of magnesium P-)ruylate in Example 8■. I got it.

(2) Preparation of ethylene-decene-1-propylene copolymer The same procedure as in Example 8 (2) was repeated except that propylene was used in place of butene-1.

(Comparative Example 1) 50 ml of IF solvent, 8 mJL (2 mmol) of IF solvent solution of ethylaluminum sesquichloride, and IP solvent slurry IQm of magnesium stearate were added to a catalyst input pipe connected to the upper part of an autoclave whose internal volume was tz and which had been replaced with argon. l (0.5 mmol), 2 ml of IP solvent solution of tetrabutoxy titanium
JL (0.05 mmol) was injected one after another in this order, and immediately after that, the mixture was put into the autoclave and a polymerization reaction was carried out under the same polymerization conditions as in Example 6.

The results are shown in Table 1.

As shown in Table 1, the catalytic activity is very low at 3.4 Kg/g-Ti, and the catalytic activity after 80 minutes is also 9.1 kg/g.
-Ti was low. In other words, the results shown in Table 1 indicate that unless a sufficient aging period is provided for the reaction between the magnesium carboxylate and the organoaluminum compound to produce a reaction product, the organoaluminum compound and the titanium compound will immediately react. This indicates that a highly active catalyst component is not produced, and the low catalyst activity after 60 minutes indicates that the durability of the catalyst's activity is also poor.

(Comparative Example 2) The same procedure as Comparative Example 1 was conducted except that butylethylmagnesium was used instead of magnesium stearate.

The results are shown in Table 1.

From the results shown in Table 1, it can be seen that when a reducing magnesium compound such as butylethylmagnesium is used as component (A), the catalyst is deactivated during polymerization to a large extent and the sustainability of the activity is low.

(Example 12) An ethylene copolymer was prepared in the same manner as in Example 2 except that butene-1 was used instead of propylene.

The results are shown in Table 1.

(Example 13) An ethylene copolymer was prepared in the same manner as in Example 4 except that octene-1 was used instead of hexene-1.

The results are shown in Table 1.

[Brief explanation of drawings]

FIG. 1 is a flowchart diagram illustrating the method of the present invention.

Claims (2)

[Claims] (1) Presence of a catalyst obtained from a reaction product of a magnesium carboxylate and an organoaluminum compound and a titanium compound, or a catalyst obtained from a reaction product of a magnesium carboxylate and a titanium compound and an organoaluminum compound Below, ethylene and α with 3 to 4 carbon atoms
- A method for producing linear low-density polyethylene, which comprises polymerizing an olefin and an α-olefin having 6 to 12 carbon atoms. (2) The titanium compound has the following formula Ti(OR^1)_mX_4_-_m (wherein, R^1 represents an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 10 carbon atoms, and represents a halogen atom, m is 0≦m≦4
It is a real number that satisfies the following. ) A method for producing linear low density polyethylene according to claim 1.