JPH01282204A - Production of ethylenic copolymer - Google Patents

Abstract

PURPOSE:To produce the subject copolymer in high yield by copolymerizing of ethylene and unsaturated carboxylic acid (ester) in the presence of Lewis acid, using catalyst composing oxygen-containing inorganic chromium compound and organic metallic compound containing metal of I-V groups of the periodic table as main components. CONSTITUTION:Ethylene is copolymerized with unsaturated carboxylic acid (e.g., acrylic acid) or unsaturated carboxylic acid ester in the presence of Lewis acid (e.g., ethylaluminumdichloride) and using a catalyst composing (A) oxygen- containing inorganic chromium compound [e.g., CrO2Cl2, Cr(NO3)3, CrO2Cl.C10H9 N2 complex] and (B) organic metallic compound containing metal of I-V groups of the periodic table (e.g., methyllithium, ethylbuthylmagnesium or buthylaluminumsesquichloride) as main components. The catalyst is preferably b/a=1-1000 in case that (a) is mol number of chromium atom in the component A and (b) is mol number of metal atom in the component B.

Description

Detailed Description of the Invention [Industrial Application] The present invention relates to a method for producing an ethylene copolymer, and more specifically, the present invention relates to a method for producing an ethylene copolymer. The present invention relates to a method for efficiently producing a copolymer.

[Prior art and problems to be solved by the invention] Polyethylene has traditionally been water resistant and chemical resistant.

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, a method is known in which ethylene is copolymerized with an unsaturated carboxylic acid ester. For example, JP-A-55-11890
No. 5 or JP-A-59-80413 proposes a method for copolymerizing olefins and unsaturated carboxylic esters, but both have low copolymerization activity, and copolymers of unsaturated carboxylic esters In addition to the low conversion rate, there are problems in that the copolymer composition cannot be controlled arbitrarily.

In addition, the present inventors have already proposed a method for improving the conversion rate of unsaturated carboxylic esters into copolymers by copolymerizing ethylene and unsaturated carboxylic esters using a chromium-based catalyst (Unexamined Japanese Patent Publication No. (Sho 61-278508, Japanese Unexamined Patent Publication No. Sho 62-86009).

However, even with this method, the copolymerization activity was still not sufficient, and the content of unsaturated carboxylic acid ester residues in the copolymer was also not sufficient.

When a chromium-based catalyst is used, the chromium compound remaining in the copolymer is usually removed by deashing to render the copolymer harmless and prevent deterioration of physical properties.

Therefore, in order to avoid or reduce such post-treatments, it is necessary that the copolymer yield per unit chromium (ie, copolymerization activity) be as high as possible. Furthermore, if the content of unsaturated carboxylic acid or its ester in the copolymer can be greatly changed, the mechanical properties of the ethylene copolymer, such as flexibility, can be changed over a wide range, and its uses and applications can be changed widely. The field will expand.

[Means for Solving the Problems] As a result of extensive research in order to solve these problems, the present inventors have found that by carrying out copolymerization using a specific catalyst, copolymerization activity and unsaturation can be reduced. It was discovered that the conversion rate of carboxylic acid or unsaturated carboxylic acid ester into a copolymer can be further improved, and based on this knowledge, the present invention was completed.

That is, the present invention uses a catalyst containing [A] an oxygen-containing inorganic chromium compound and [B] an organometallic compound of Groups ① to V of the periodic table, and ethylene and an unsaturated carboxylic acid or an unsaturated carboxylic acid in the presence of a Lewis acid. The present invention provides a method for producing an ethylene copolymer characterized by copolymerizing a saturated carboxylic acid ester.

First, in the method of the present invention, [^] chromium oxide, halogen-containing chromium, chromium inorganic salts, and adducts thereof are used as oxygen-containing inorganic chromium compounds.

Here, as chromium oxide, for example, CrO3°Or, 0
3. Examples of halogen-containing chromium include Cr02CR2, (:r(0)1)Cr2. (:
Examples include r(C4'04)s. Further, as the chromium inorganic salt, Cr(NO9) 3. Or (PO4)
3 , (:r to (S04) 2 , (:r 2
(504) 3 to 2504°CrNa (S04)2.
Cs2CrO4, CrLi0. , CrBa04° (NH4) 2Cr04. (NL) 2cr207,
2Cr04. ni, fl:ro,.

Li2Cr0a, Na2(:ro4.PbCr
0. , Rt12Cr04. 5rCr04゜CoC
r2O4, K2CrO4, MgCr2O4, MnCr2
O,, NiCr2O4゜Na2Cr2O7, ZnCr2
Examples include O4.

Further, as adducts of the oxygen-containing inorganic chromium compound, CrO3 pyridine complex, Cr0sC4''C:+oH9
Nz complex.

In addition to Cr0CP, ・C+oHJ2 complex, GrNa(SO
4) 212Hz.

Examples include hydrates such as CrK(SO4)z42LO.

In the present invention, t fi or two or more kinds of compounds selected from the above specific inorganic chromium compounds are used as [A] the oxygen-containing inorganic chromium compound.

Next, in the method of the present invention, [8] organometallic compounds belonging to groups 1 to V of the periodic table are used as the organometallic compound.

Here, as the organometallic compound of Groups 1 to 1 of the periodic table, a compound represented by the general formula % [ ] is used. R' in this formula [I] is an alkyl group having 1 to 20 carbon atoms, an alkenyl group,
Indicates a cycloalkyl group, aryl group or aralkyl group. Specific examples of R+ include methyl group, ethyl group, n-
Propyl group, i-propyl group, n-butyl group, i-butyl group, hexyl group.

Examples include 2-ethylhexyl group and phenyl group.

Further, M represents lithium, sodium, potassium, magnesium, zinc, cadmium, aluminum, boron, gallium, silicon, tin, antimony, or bismuth. In general, X represents a halogen atom, such as chlorine, bromine, or iodine.

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

Specific examples of the compound represented by formula [1] above include alkyllithium such as methyllithium, ethyllithium, propyllithium, butyllithium, diethylmagnesium, ethylbutylmagnesium, di-n-butylmagnesium, ethylchloromagnesium, ethyl Alkylmagnesium such as butylmagnesium, dialkylzinc such as dimethylzinc, diethylzinc, dipropylzinc, dibutylzinc, alkylgallium compounds such as trimethylgallium, triethylgallium, tripropylgallium, tributylgallium, triethylboron, tripropylboron, tributylboron and alkyltin compounds such as tetraethyltin, tetrapropyltin, tributylchlorotin, tetraphenyltin, and triphenylchlorotin. In addition, there are various examples of compounds when M is aluminum, and specifically, trialkylaluminum compounds such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trioctylaluminum, and diethylaluminum dialkylaluminum monohalides such as monochloride, diethylaluminium monopromide, diethylaluminium monoiodide, diisopropylaluminum monochloride, diisobutylaluminum monochloride, dioctylaluminum monochloride, or methylaluminum sesquichloride, ethylaluminum sesquichloride, ethylaluminum sesquipromide Preferred are alkyl aluminum sesquihalides such as aluminum chloride, butyl aluminum sesquichloride, and mixtures thereof. 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 oxygen-containing inorganic chromium compound [A] to the organometallic compound of Group 1-V of the periodic table used as the [81 organometallic compound] is not particularly limited, but usually The number of moles of chromium atoms in the former is (a),
When the number of moles of metal atoms in the latter is (b), (
b)/(a) value (1,1 to 5000, preferably 1
It may be set to a ratio of ~10,000.

In the method of the present invention, an ethylene copolymer is produced by copolymerizing ethylene and an unsaturated carboxylic acid or an unsaturated carboxylic acid ester 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 halogenated compounds such as aluminum, boron, zinc, tin, magnesium, antimony, e.g. aluminum chloride,
Aluminum bromide, ethylaluminum dichloride, diethylaluminium monochloride, boron trichloride, zinc chloride, tin tetrachloride, alkyltin halide, magnesium chloride, antimony pentachloride, antimony trichloride, etc. are preferred, and aluminum chloride, odorous aluminum chloride, ethylaluminum dichloride, etc.

As ethylene, which is the main raw material for the copolymer according to the present invention, in addition to using ethylene alone, α-olefins having 3 to 20 carbon atoms are produced in consideration of the purpose of use of the copolymer, etc. Attributes of the copolymer: For example, a substance added in an amount sufficient to change crystallinity may be used.

The unsaturated carboxylic acid or its ester to be copolymerized with ethylene is not particularly limited, but a compound represented by the formula % is usually used. This - formula [11]
R2 represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group, and R3 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

Indicates an alkenyl group, a cycloalkyl group, an aryl group, or an aralkyl group. Further, P represents an integer of 0 to 20.

Specific examples of the unsaturated carboxylic acid represented by formula [11] above include acrylic acid, methacrylic acid, α-chloroacrylic acid, 3-butenoic acid, 4-pentenoic acid, 6-hebutenoic acid, and 8-nonenoic acid. .

Examples include lO-undecenoic acid.

Specific examples of unsaturated carboxylic acid esters include methyl acrylate and ethyl acrylate.

Propyl acrylate, butyl acrylate, acrylic acid n
-Octyl, 2-ethylhexyl acrylate 1 Acrylic acid esters such as benzyl acrylate; methyl methacrylate, ethyl methacrylate.

α-substituted acrylic esters such as butyl methacrylate, 2-ethylhexyl methacrylate, phenyl methacrylate, methyl α-chloroacrylate, ethyl α-chloroacrylate; methyl 3-butenoate, ethyl 3-butenoate, 4- Methyl pentenoate, ethyl 6-heptenoate, 8-
Methyl nonenoate, 10-methyl undecenoate, 10-
Propyl undecenoate, butyl 10-undecenoate,
Hexyl 10-undecenoate, octyl 10-undecenoate.

Examples include carboxylic acid esters having a terminal double bond such as decyl 10-undecenoate, cyclohexyl 10-undecenoate, and phenyl 10-undecenoate, and these can be used alone or in a mixture of two or more. can.

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

The ratio of the Lewis acid and unsaturated carboxylic acid or ester thereof used is 0.1 to 10 (molar ratio), preferably 0.2 to 1, of the Lewis acid to 1 part of the unsaturated carboxylic acid or ester thereof. (molar ratio).

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, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, and halogenated carbons are used as the combined solvent. Specifically, pentane, hexane, heptane, octane, decane, dodecane, cyclohexane, benzene, toluene, xylene, ethylbenzene, chlorobenzene, ethylene dichloride, tetrachloroethylene, kerosene, etc. are used. As for the polymerization conditions, the reaction pressure is normal pressure to 100 kg/cm'G, preferably normal pressure to 30 kg/cm'G, and the reaction temperature is -8[
The temperature is 1 to 200°C, preferably -50 to 100°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.

[Real δζ example] Next, the present invention will be explained in more detail with reference to Examples.

Example 1 (1) Preparation of chromium catalyst component 0.3 g (2 mmol) of chromyl chloride was placed in a 200 mJ flask purged with argon, and 200 mJ+ of hexane was added thereto to dissolve it. The obtained solution was used as a chromium catalyst component in the following reaction.

(2) Production of copolymer In a 500mR pressure-resistant glass container purged with argon, 300ml of toluene) and 0.87ml of ethyl acrylate)
(8 mmol) and 8 mmol of aluminum trichloride ground in a ball mill under an argon stream were added, and then 0.5 mmol of diethylaluminum monochloride and 235 mmol of the chromium catalyst component prepared in (1) above were added. Next, ethylene was introduced into the glass container, and the polymerization reaction was carried out at 20°C for 3 hours while maintaining the pressure at 3 kg/cm"G. After the reaction was completed, the ethylene was depressurized and the product was poured into methanol. The resulting solid copolymer was collected in a furnace, deashed with a hydrochloric acid-methanol mixture, and then extracted with acetone for 5 hours to remove the amorphous polymer. It was dried under reduced pressure at ℃ for 2 hours to obtain 4.26 g of a white copolymer.The catalyst activity (polymerization activity) was 34.8 kg/g.chromium.The obtained copolymer was subjected to infrared absorption spectrum analysis. However,
The absorption by the carbonyl group at the 1730 cm-' position is
Absorption due to an ether bond was observed at a position of 1160 cm-'. These absorptions revealed that the content of ethyl acrylate in the copolymer was 18 t%, and the conversion rate of ethyl acrylate to the copolymer was 95%. Furthermore, when the melting point of this copolymer was measured, it was found to be 125°C.
and the melting point of polyethylene produced with the same catalyst is 135
It is considered that ethyl acrylate is introduced into the ethylene polymer chain in a form that disturbs the crystals.

The above results are shown in Table 1.

Examples 2-6. Comparative Examples 1 to 8 Polymerization reactions were carried out in the same manner as in Example 1 except for the conditions shown in Table 1. The results are shown in Table 1.

Example 7. Comparative Example 9 10 g of octene-1 was added before introducing ethylene, and copolymerization was carried out under the other conditions shown in Table 1 to obtain a terpolymer. The obtained copolymer showed absorption by a carbonyl group at the 1730 cm'' position, absorption due to an ether bond at the 1L60c+a-' position, and four or more methylene groups bonded at the 720 cl' and 730 cl' positions in the infrared absorption spectrum analysis. Absorption caused by this was observed.

In addition, as a result of C-NMR analysis, the absorption corresponding to the hexyl branch due to octene-1 was found to be 13.4.22.
．． 2.27.0.29.4.31.8.34.41)9
It was recognized around 11. Further, the composition of this terpolymer was determined by the measurement results of ')I-NMH, and the results of 0 or more are shown in Table 1.

Added 10g of octene-1 in addition to ethylene ◆2E8; Ethyl acrylate 10-UME, Methyl 10-undecenoate E) I
A, 2-ethylhexyl acrylate AA
, acrylic acid*3 CrO□C22; chromyl chloride Cr5Ls
Chromium nistearate Cr (acac) 3
; trisacetylacetonatochromium 4 DEAC, diethylaluminum monochloride SnEt4; tetraethyltin Biφ, ; triphenyl bismuth [Effects of the invention] According to the method of the present invention, [^] using an oxygen-containing inorganic chromium compound, [B] By using an organometallic compound belonging to group 5x-v of the periodic table as an organometallic compound, copolymerization can be carried out with high activity and good yield, reducing the deashing load and also reducing unsaturated carboxylic acids or their copolymerization. The conversion rate of ester to copolymer can be improved. Therefore, even in the low charge range of the unsaturated carboxylic acid or its ester, a copolymer containing a high proportion of the unsaturated carboxylic acid or its ester can be obtained.

Moreover, the ethylene copolymer obtained by the method of the present invention has improved printability and adhesiveness, as well as low-temperature flexibility and
Low temperature aI impact resistance, bending crack resistance. Transparency, ESC
Further improvements have also been made in R.

Claims (1)

[Claims] (1) Using a catalyst mainly composed of [A] an oxygen-containing inorganic chromium compound and [B] an organometallic compound of groups I to V of the periodic table, ethylene and an unsaturated carboxylic acid or an unsaturated acid are combined in the presence of a Lewis acid. A method for producing an ethylene copolymer, which comprises copolymerizing a carboxylic acid ester.