JPS6322807A - Production of ethylenic copolymer - Google Patents

Abstract

PURPOSE:To carry out copolymerization of ethylene and an unsaturated carboxylic acid in high yield and catalyst activity, by using a catalyst composed mainly of a chromium compound and an organometallic compound of a metal of group I-V of the periodic table. CONSTITUTION:Ethylene and an unsaturated carboxylic acid [e.g. the compound of formula (R<1> is H, halogen, 1-20C alkyl, etc.; p is 0-20), etc.] are copolymerized in the presence of a catalyst composed mainly of (A) a transition metal compound and (B) an organometallic compound. The component A is a chromium compound [e.g Cr(CH3COO)3, etc.] and the component B is an organometallic compound of a metal of group I-V of the periodic table (e.g. methyllithium, trimethylaluminum, etc.). EFFECT:The content of unsaturated carboxylic acid in the copolymer can be controlled over a wide range by varying the charging amount of the unsaturated carboxylic acid and the kind of Lewis acid. USE:The obtained polymer is effective in applications requiring adhesivity, printability, low-temperature flexibility, low-temperature impact resistance, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing an ethylene copolymer obtained by copolymerizing ethylene and an unsaturated carboxylic acid. The ethylene copolymer obtained by the method of the present invention can be effectively used in applications requiring adhesiveness, printability, low-temperature flexibility, low-temperature impact resistance, and the like.

[Prior art and problems to be solved by the invention] Conventionally, polyethylene has good water resistance and chemical resistance.

It has excellent electrical properties and is used in a wide range of applications. However, because it is chemically inert, it has the disadvantage of poor adhesion, printability, and dyeability, which limits its use in applications that require these properties.

In order to improve these properties of polyethylene, it has been proposed to copolymerize ethylene with an unsaturated carboxylic acid (Japanese Patent Publication No. 10275/1983).

44-2228, 48-37756) However, the conventional methods had problems in that the copolymerization activity was low and the conversion rate of unsaturated carboxylic acid was low. Furthermore, the content of unsaturated carboxylic acid in the resulting copolymer was only low.

[Means for solving problems]

The present inventors have conducted intensive research in order to develop an extremely efficient method for producing an ethylene copolymer that solves the above-mentioned conventional problems. As a result, by copolymerizing ethylene and unsaturated carboxylic acid using a specific catalyst, it is possible to improve the copolymerization activity and the conversion rate of unsaturated carboxylic acid into a copolymer. It has been discovered that the unsaturated carboxylic acid content of the polyester can be controlled over a wide range, and based on this knowledge, the present invention has been completed.

That is, the present invention produces an ethylene copolymer by copolymerizing ethylene and an unsaturated carboxylic acid in the presence of a Lewis acid using a catalyst mainly composed of [A] a transition metal compound and [B] an organometallic compound. A method for producing an ethylene copolymer, characterized in that [A] a chromium compound is used as the transition metal compound, and [B] an organometallic compound of Groups 1 to 2 of the periodic table is used as the organometallic compound. It provides:

The catalyst used in the method of the present invention includes [A] a transition metal compound and [
B] The main component is an organometallic compound.

First, in the method of the present invention, a chromium compound is used as the transition metal compound [A]. As the chromium compound, at least one selected from the group consisting of chromium carboxylates, chromium alkoxy compounds, chromium chelate compounds, chromium π-complexes, chromium aryl compounds, and chromium halides is used.

Here, as a chromium carboxylate, the general formula % formula % [In the formula, R2 to R1e are each an alkyl group having 1 to 20 carbon atoms, an alkenyl group, a vinyl group, a cycloalkyl group,
It represents an aryl group, a haloalkyl group, an aralkyl group, or a hydrogen atom, and l is a real number of 1 or more. ] is used. Specifically, Cr(CH3COO
)3. Aliphatic carboxylates such as Cr(C+d13sCOO)z, Cr(CJsCOO)z, Cr(CH3
' Aromatic carboxylic acid salts such as CJsCOO)s, and carboxylic anhydride adducts and ester adducts of the above carboxylic acid salts.

Examples include ether adducts and ketone adducts. These adducts include acetic anhydride and propionic anhydride.

Fatty acid anhydrides such as butyric anhydride, isobutyric anhydride, valeric anhydride, isovaleric anhydride, aromatic anhydrides such as benzoic anhydride, toluic anhydride, cinnamic anhydride, phthalic anhydride, maleic anhydride; methyl formate, formic acid Ethyl, propyl formate, butyl formate, methyl acetate.

Ethyl acetate, propyl acetate, butyl acetate, hexyl acetate, octyl acetate, benzyl acetate, vinyl acetate, phenyl acetate, benzyl acetate, cyclohexyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate.

Octyl propionate, phenyl propionate.

Benzyl propionate, methyl butyrate, ethyl butyrate.

Propyl butyrate, butyl butyrate, amyl butyrate, octyl butyrate, methyl valerate, ethyl valerate, propyl valerate, butyl valerate, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, methacrylate Ethyl acid, butyl methacrylate, methyl chloroacetate, ethyl dichloroacetate, ethyl crotonate.

Aliphatic esters such as ethyl pivalate, dimethyl maleate, ethyl cyclohexanecarboxylate; methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, benzoate, octyl acid, cyclohexyl benzoate,
Aromatic esters such as benzyl benzoate, methyl toluate, ethyl toluate, ethyl ethylbenzoate, ethyl anisate; ethers such as methyl ether, ethyl ether, isopropyl ether, n-butyl ether, amyl ether, tetrahydrofuran, anisole, diphenyl ether, etc. , acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, and benzoquinone.

Next, as a chromium alkoxy compound, the general formula is
A compound represented by Cr(OR) 4-a

It represents an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group. Specific examples of R'' include methyl group,
Ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, hexyl group, 2-
Examples include ethylhexyl group and phenyl group. Further, XI represents a halogen atom, ie, chlorine, bromine, iodine, etc. m is a real number satisfying 0≦m<4.

Specific examples of the compound represented by the above general formula [1] include tetramethoxychromium, tetraethoxychromium, tetra-n-butoxychromium, tetra-1-butoxychromium, tetra-t-butoxychromium, tetrahexyloxychromium, Tetrastearyloxychromium, tetraphenoxychromium.

Examples include triethoxychrome monochloride, jetoxychrome dichloride, tri-n-butoxychrome monochloride, tri-t-butoxychrome monochloride, and the like.

Further, the chromium chelate compound specifically has the formula Cr
Chromium trisacetylacetonate represented by (acac) 3 Chromium tris(2-methyl-1,3-butanedioate) represented by Cr (mbd) 3.

Chromtris (1,3
-butanedione), etc. Here (ac
ac) represents an acetylacetonate group, and chromium trisacetylacetonate is represented by the following structural formula. In addition, (++bd) represents a 2-methyl-1,3-butanedioate group, which is represented by the structural formula of chromium tris (2-methyl-1,3-butanedioate). Indicates a 3-butandionate group, and chromium tris(1,3-)tanedionate is represented by the following structural formula.

As a chromium π-complex, (cp) zCr ((c
p) represents a cyclopencitagenyl group), (C4H6) zc
r T: represented bisbenzenechromium + (2CJ
S) (CJ6) Diphenylbenzene chromium represented by Cr, dihexamethylbenzene chromium represented by the formula 1
π-cyclopentadienyl promochromium acetylacetate represented by the formula 1 π-cyclopentadienyl (benzene) chromium represented by the formula 1 Examples include aromatic ring π-complexes, π-allyl complexes such as tris(η-allyl)chromium, and tetrakis(η-allyl)chromium.

Furthermore, examples of the chromaryl compound include diphenylchromium, triphenyltris(tetrahydrofuran)chromium, and the like.

Next, preferred chromium halides are those represented by the general formula CrX'', (wherein, X2 represents a halogen atom and n represents 2 or 3).Specifically, chromium trichloride, Examples include chromium tribromide, chromium triiodide, chromium dichloride, chromium tribromide, and chromium diiodide.

In the present invention, it is preferable to use one or more chromium compounds selected from the above as the transition metal compound [A].

Next, in the method of the present invention, as the organometallic compound [B], an organometallic compound belonging to Groups 1 to V of the periodic table is used.

Here, as the organometallic compound of groups r-v of the periodic table, a compound represented by the general formula %() is used. RIZ in this general formula [■] is an alkyl group having 1 to 20 carbon atoms.

Indicates an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group. Specific examples of RIZ include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, hexyl group, 2-ethylhexyl group, and phenyl group. Further, M represents lithium, sodium, potassium, magnesium, zinc, cadmium, aluminum, boron, gallium, silicon, tin, antimony or bismuth. Furthermore, X3 represents a halogen atom, ie, chlorine, bromine, iodine, etc.

i is the valence of M, and is usually a real number from 1 to 5. is a real number with O<k≦i and shows various values.

Specific examples of the compound represented by the general formula (II) include alkyllithiums such as methyllithium, ethyllithium, propyllithium, and butyllithium, diethylmagnesium, ethylbutylmagnesium, and di-n-butylmagnesium.

Alkylmagnesiums such as ethylchloromagnesium, ethylbutylmagnesium, dialkylzincs such as dimethylzinc, diethylzinc, dipropylzinc, dibutylzinc, trimethylgallium.

Alkyl gallium compounds such as triethyl gallium, tripropyl gallium, and tributyl gallium; alkyl boron compounds such as triethyl boron, tripropyl boron, and tributyl boron; tetraethyl tin, tetrapropyl tin, tributylchlorotin, tetraphenyltin, triphenylchlorotin, etc. Examples include alkyltin compounds. Furthermore, there are various examples of compounds where M is aluminum, specifically trimethylaluminum and triethylaluminum.

Trialkylaluminum compounds such as triisopropylaluminium, triisobutylaluminum, trioctylaluminum, and diethylaluminum monochloride, diethylaluminum monopromide, diethylaluminium monoiodide, diisopropylaluminum monochloride, diisobutylaluminum monochloride, dioctylaluminum monochloride, etc. Preferred are dialkylaluminum monohalides or alkylaluminium sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum sesquipromide, butylaluminum sesquichloride, and mixtures thereof are also preferred. Furthermore, alkyl group-containing aluminoxane produced by the reaction of alkyl aluminum and water can also be used.

Among these, aluminum compounds, tin compounds,
Magnesium compounds are preferably used.

In the method of the present invention, the ratio of the chromium compound used as the transition metal compound [A] and the organometallic compound of Groups 1 to 2 of the periodic table used as the organometallic compound [B] is not particularly limited; Usually 0.1 to 5000 (molar ratio) of metal atoms in the latter to chromium atoms in the former.
, preferably a ratio of 1 to 1000 (molar ratio).

In the method of the present invention, an ethylene copolymer is produced by copolymerizing ethylene and an unsaturated carboxylic acid in the presence of a Lewis acid using the above catalyst.

Examples of the Lewis acid include Lewis acid compounds capable of forming a complex with a lone pair of electrons of a polar group, such as halogenated compounds of Group 1-V or Group II of the periodic table. Especially aluminum, boron, and zinc.

Halogenated compounds such as tin, magnesium, antimony, such as aluminum chloride, aluminum bromide, ethylaluminum dichloride, ethylmalminium sesquichloride, diethylaluminum chloride, triethylaluminum, trimethylaluminum, boron trichloride, zinc chloride, tin tetrachloride, Preferred are alkyltin halides, magnesium chloride, antimony pentachloride, antimony trichloride, and particularly preferred is aluminum chloride.

These include aluminum bromide and ethylaluminum dichloride.

Further, the unsaturated carboxylic acid to be copolymerized with ethylene is not particularly limited, but a compound represented by the general formula % (%) is usually used. This general formula (III
), R1 is a hydrogen atom, 9 halogen atoms, and a carbon number of 1 to 20.
represents an alkyl group, alkenyl group, cycloalkyl group, aryl group or aralkyl group, and p represents an integer of 0 to 20.

Specific examples of the unsaturated carboxylic acid represented by the above general formula (III) include acrylic acid and methacrylic acid.

Examples include α-chloroacrylic acid, 3-butenoic acid, 4-pentenoic acid, 6-hebutenoic acid, 8-nonenoic acid, 10-undecenoic acid, etc., and these can be used alone or in combination of two or more types. be able to.

The ratio of the above unsaturated carboxylic acid to ethylene may be arbitrarily selected depending on the physical properties required of the intended copolymer.

The ratio of the Lewis acid and the unsaturated carboxylic acid used is 30 or less (molar ratio), preferably 0.2 to 5 (molar ratio) of the Lewis acid to 1 part of the unsaturated carboxylic acid.

There are no particular restrictions on the type of polymerization, and slurry polymerization is used.

Either solution polymerization, gas phase polymerization, etc. are possible, and both continuous polymerization and discontinuous polymerization are possible.

In this case, fatty acid hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons are used as the polymerization solvent. Specifically, pentane, hexane, heptane, octane, decane, dodecane, cyclohexane, benzene,
Toluene, xylene.

Ethylbenzene, chlorobenzene, ethylene dichloride, kerosene, etc. are used. As for the polymerization conditions, the reaction pressure is normal pressure to 100 kg/cJG, preferably normal pressure to 30 kg/cJG.
colG, and the reaction temperature is -80 to 200°C, preferably -50 to 80°C. Incidentally, the reaction time is arbitrary, but may be appropriately selected usually between 1 minute and 10 hours. Molecular weight adjustment during polymerization can be carried out by known means, such as hydrogen.

〔Effect of the invention〕

According to the method of the present invention, [A] a chromium compound is used as the transition metal compound, and [B] an organometallic compound of Groups I to V of the periodic table is used as the organometallic compound, thereby achieving high activity and good yield. Copolymerization can be carried out, and the conversion rate of unsaturated carboxylic acids into copolymers can be improved.

Furthermore, by changing the amount of unsaturated carboxylic acid charged or the type of Lewis acid, the unsaturated carboxylic acid content in the copolymer can be controlled over a wide range.

Furthermore, the ethylene copolymer obtained by the method of the present invention has improved printability and adhesion compared to ethylene homopolymers, as well as low-temperature flexibility, low-temperature impact resistance, bending crack resistance, and transparency. It has improved properties.

The present invention is not limited to this unless it exceeds the scope of the present invention.

Example 1 (1) Preparation of chromium catalyst component Argon-substituted 200mj! into a flask with a diameter of 5~
Add 10 stainless steel balls of tOW, then add 3.6 g (4 mmol) of chromium stearate and 100 m of toluene.
1 and ball milled for 10 hours while stirring at room temperature. Next, add toluene to this to bring the total amount to 200.
mj! Closed. As a result, a chromium catalyst-containing component in the form of a blackish-purple gel was obtained.

(2) Production of copolymer In a pressure-resistant glass container with an internal volume of 500LIII and replaced with argon, add 300n+/ toluene and 0.34m acrylic acid.
1 (5 mmol) and 10 mmol of ethylaluminum dichloride as a Lewis acid were added, and the mixture was stirred at 20° C. for 5 minutes to react. Then, add (1) above to this.
0.01 mmol of the chromium catalyst component prepared above and 1 mmol of diethylaluminum monochloride were added, ethylene was continuously introduced, and the copolymerization reaction was carried out at 20° C. for 3 hours while maintaining the internal pressure at 2 kg/cjG. After the reaction was completed, the ethylene was depressurized and the product was poured into methanol to precipitate it. The obtained solid was collected by filtration, deashed and washed with a hydrochloric acid/methanol mixture to remove soluble components, and then extracted with acetone for 5 hours to remove the amorphous polymer. Furthermore, the extraction residue was dried under reduced pressure at 80° C. for 2 hours to obtain 6.6 g of a white copolymer. Catalytic activity (polymerization activity) was 12.7 kg/g.chromium.

Next, as a result of infrared absorption spectrum analysis of this copolymer, absorption due to the carbonyl group of the aluminum carboxylic acid salt was observed at the position of 1580 cm-', and absorption due to the carbonyl group of the carboxylic acid was observed at the position of 1700 cm-'.

Furthermore, absorption due to the carbonyl group of the carboxylic acid methyl ester was observed at a position of 1730 cm-'.

When this copolymer was boiled in concentrated hydrochloric acid for 8 hours, 1
Absorption due to the carbonyl group of the carboxylic acid was observed only at the 70 Q ctn-' position. In addition, 1160
Absorption due to an ether bond was also observed at the C1l-' position. The content of acrylic acid in the copolymer was calculated from these absorptions and was 1.8 mol% (4.5% by weight), and the conversion rate of acrylic acid to the copolymer was 86%. .

Further, the melting point of this copolymer was measured by differential thermal analysis and was found to be 130°C. Furthermore, nuclear magnetic resonance (NMR)
According to spectral analysis, no absorption of long-chain alkyl branches was observed, and from the above, it is considered that acrylic acid is introduced into the ethylene polymer chain in a form that disturbs the crystals. The above results are shown in Table 1.

Example 2 8.0 g of a copolymer was obtained in the same manner as in Example 1 (2), except that 10 mmol of diethyl aluminum chloride was used as the Lewis acid in place of ethyl aluminum dichloride. The results are shown in Table 1.

Example 3 0.9 g of a polymer was obtained by carrying out the same operation as in Example 1 (2), except that 20 mmol of aluminum trichloride was used as the Lewis acid instead of ethyl aluminum dichloride. The results are shown in Table 1.

Example 4 The amount of ethylaluminum dichloride used as the Lewis acid was 40 mmol, and acrylic acid was obtained. The results are shown in Table 1.

Example 5 (1) Preparation of chromium catalyst component In a 300o+1 flask purged with argon, 1.5 g of chromium acetate hydrate (Cr(C1hCOO)z .HzO) was added.
1 g (4°45 mmol), 40 ml of acetic anhydride, and 40 ml of acetic acid. was added and reacted for 20 hours under reflux with stirring, and then acetic acid and acetic anhydride were distilled off under reduced pressure to obtain a green solid. Next, under an argon stream.

It was dried at 120° C. for 48 hours, the temperature was lowered, and toluene was added to obtain a 200 mJ catalyst slurry.

The solid material in the slurry is Cr(CHzCOO)3
'(CH3CO) tO chromium acetate anhydride.

(2) Production of copolymer As the chromium catalyst component, the one prepared in +11 above was used as the chromium catalyst component.
．． 5.1 g of a copolymer was obtained by carrying out the same operation as in Example 1 (2) except that 0.01 mmol was used. The results are shown in Table 1.

Example 6 1.2 g of a copolymer was obtained in the same manner as in Example 5, except that 20 mmol of aluminum trichloride was used as the Lewis acid. The results are shown in Table 1.

Example 7 (1) Preparation of chromium catalyst component Argon-substituted 200s+j! 2.1 g (6 mmol) of chromium trisacetylacetonate was placed in a flask, and 200a+42 of toluene was added thereto to dissolve it.

(2) Production of copolymer The chromium catalyst component prepared in Tl) above was used as a chromium catalyst component.
6.3 g of a copolymer was obtained in the same manner as in Example 1 (2) except that 0.01 mmol was used. The results are shown in Table 1.

Example 8 0.8 g of a copolymer was obtained in the same manner as in Example 7 except that 20 mmol of aluminum trichloride was used as the Lewis acid. The results are shown in Table 1.

Example 9 (1) Preparation of chromium catalyst component In a 200ml flask purged with argon, 1.22g (6.7 mmol) of biscyclopentadienylchromium and 200a+7! of toluene were placed. was added and dissolved. The obtained solution was used as a chromium catalyst component in the following reaction.

(2) Production of copolymer The chromium catalyst component prepared in (1) above was used as a chromium catalyst component.
4.9 g of a copolymer was obtained in the same manner as in Example 1 (2) except that 0.01 mmol was used. The results are shown in Table 1.

Example 10 (1) Preparation of chromium catalyst component 0.95 g (6 mmol) of chromium trichloride was placed in a 200+ lIl flask purged with argon, and then a flask with a diameter of 5
Ten ~3 U+ stainless steel balls were put therein, toluene 150+wj2 was added thereto, and ball milling was carried out for 24 hours with stirring at room temperature, and a chromium-containing slurry was taken out. The obtained chromium-containing slurry was used as a chromium catalyst component in the following reaction.

(2) Preparation of copolymer As a chromium catalyst component, the one prepared in the above (11) was used as a chromium catalyst component.
1.5 g of a copolymer was obtained in the same manner as in Example 1 (2) except that 0.01 mmol was used. The results are shown in Table 1.

Example 11 4.2 g of a copolymer was obtained in the same manner as in Example 1 (2) except that 10 mmol of triethylaluminum was used as the Lewis acid. The results are shown in Table 1.

Example 12 3.8 g of a copolymer was obtained in the same manner as in Example 1 (2) except that 1049 mol of trimethylaluminum was used as the Lewis acid. The results are shown in Table 1.

Comparative Example 1 0.5 g of a copolymer was obtained in the same manner as in Example 1 (2) except that 0.01 mmol of titanium trichloride was used in place of the chromium catalyst component. The results are shown in Table 1.

Comparative Example 2 In place of the chromium catalyst component, 0.01% vanadium trichloride
0.3 g of a copolymer was obtained in the same manner as in Example 1 (2) except that mmol was used. The results are shown in Table 1.

Comparative Example 3 Same as Example 1 except that 0.01 mmol of vanadium trisacetylacetonate was used instead of the chromium catalyst component.
1.5 g of a copolymer was obtained in the same manner as in (2). The results are shown in Table 1.

Comparative Example 4 0.2 g of a copolymer was obtained in the same manner as in Comparative Example 3, except that 10 mmol of aluminum trichloride was used as the Lewis acid. The results are shown in Table 1.

Claims (3)

[Claims] (1) Produce an ethylene copolymer by copolymerizing ethylene and unsaturated carboxylic acid in the presence of a Lewis acid using a catalyst containing [A] a transition metal compound and [B] an organometallic compound as main components. A method for producing an ethylene copolymer, characterized in that [A] a chromium compound is used as the transition metal compound, and [B] an organometallic compound of groups I to V of the periodic table is used as the organometallic compound. (2) The chromium compound is a chromium carboxylate, a chromium alkoxy compound, or a chromium chelate compound. The manufacturing method according to claim 1, wherein the chromium π-complex, chromium aryl compound, and chromium halide are at least one selected from the group consisting of chromium halides. (3) Unsaturated carboxylic acid has the general formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R^1 is a hydrogen atom, a halogen atom, or a carbon number of 1 to
20 alkyl groups, alkenyl groups, cycloalkyl groups,
Represents an aryl group or an aralkyl group, p is 0 to 20
indicates an integer. ] The manufacturing method according to claim 1, which is a compound represented by: