JPS588711A - Production of copolymer - Google Patents

Abstract

PURPOSE:To obtain a low-density, low-MI copolymer and, at the ame time, to decrease the amount of expensive 5C or higher olefins, by copolymerizing ethylene and alpha-olefin first by a solution process and then by a vapor phase process while selecting the kinf of the olefin used. CONSTITUTION:In the copolymerization of ethylene and alpha-olefins in the presence of a catlyst consisting of (A) a solid catalytic component containing Mg, Ti and a halogen and (B) an organometallic compound component, ethylene and about 1-250mol%, based on ethylene 5-15C olefins (e.g., 4-methyl-1-pentene) are copolymerized at 0-120 deg.C in the presence of a hydrocarbon solvent to form a copolymer in an amount of 1-70wt% based on total weight of the final copolymer, then the solvent is removed from the resulting copolymer (density about 0.925- 0.955) and, if necessary, an organometallic compound component is added and ethylene and about 1-250mol%, based on ethylene, 3-4C olefin (e.g., 1-butene) are fed and copolymerized in a vapor phase at about 20-110 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a childish copolymer by copolymerizing ethylene and two or more α-olefins,
More specifically, after copolymerizing ethylene and an α-olefin having 5 to 15 carbon atoms in the presence of a hydrocarbon solvent, the solvent is removed and ethylene and an α-olefin having 3 to 4 carbon atoms are copolymerized in the gas phase. - A method for producing a copolymer characterized by copolymerizing olefins.

Traditionally, Ziegler-type catalysts have been used to convert ethylene and other α
It has been known from Canadian Patent No. 664,211, etc. that it is possible to control/control the density of an ethylene copolymer by copolymerizing -olefins to produce medium to low density polyethylene. In addition, low-density polyethylene obtained by copolymerizing ethylene and other α-olefins using a Ziegler-type catalyst has superior mechanical properties such as tear resistance compared to low-density polyethylene produced by high-pressure methods. It also has the five excellent characteristics of beef: its melting point is 10 to 12 degrees higher.

Furthermore, this feature is extremely effectively exhibited by using an α-olefin having 5 or more carbon atoms. However, α-olefins with 5 or more carbon atoms are industrially expensive and have low raw VSD, which increases the cost of the copolymer and severely limits production. There is a problem.

On the other hand, as a method for producing copolymers of ethylene and other α-olefins, there is a suspension polymerization method in which 71 polymerization is carried out in a suspended state at a humidity below the melting point of the copolymer. , a solution polymerization method in which polymerization is carried out in a solution state at a temperature above the iB point of the copolymer in a hydrocarbon solution/1I11, and a method in which the copolymer is polymerized in a solution state at a temperature above the iB point, and in the presence of substantially no solvent, at a temperature below 120 ° C. A gas phase polymerization method in which polymerization is carried out in a gas phase is well known.0 When carrying out copolymerization of shikadiethylene and other α-olefins by suspension polymerization, copolymerization that is soluble in the solvent increases as the density decreases. Due to the increase in copolymerization, the bulk density of the copolymer decreases, and fouling on the reactor wall is severe.As the viscosity of the polymerization system increases, stickiness tends to occur.For this reason, the density of the copolymer decreases. If the density is 0.940 or more, almost no problems will occur during operation, but if the density of the copolymer is lowered to 0.9204, industrial operation becomes difficult.

However, in solution polymerization, the copolymer is dissolved and the operation is performed in a solution state, so the above-mentioned problems do not occur. The lower the molecular weight copolymer is, the lower the concentration of the solution must be for its longevity, and it is extremely difficult to produce a high molecular weight copolymer with an MIO of 05 or less. Moreover, solution polymerization has the disadvantage that it is difficult to obtain a copolymer in the form of powder.

On the other hand, in gas phase polymerization, it is relatively easy to produce a co7]i polymer with lower density and MI, but because it is in a gas phase, α
- It is industrially very difficult to use olefins. On the other hand, in suspension polymerization and solution polymerization, there are basically no restrictions on the selection of the type of α-olefin.

As a result of intensive research to solve the above-mentioned problems, the present inventors have developed the new production method of the present invention, and have succeeded in producing a copolymer with low density and low MI. By using a combination of α-olefins having 3 to 4 carbon atoms and α-olefins having 5 to 15 carbon atoms, which can be easily produced, expensive α-olefins having 5 to 15 carbon atoms can be easily produced.
- Use of olefins The resulting copolymer has an ability equivalent to or better than that of a copolymer of ethylene and an α-olefin having 5 or more carbon atoms. Having I: [Surprising.

That is, the present invention P, I ethylene and (a) having 3 or more carbon atoms;
(b) α-olefins having 5 to 15 carbon atoms; [A] at least magnesium, titanium, and ] Gen atom-containing solid catalyst and [B] organic gold If', in the presence of the compound: 1st stage in producing copolymer CI=: 0 to 120°C in the presence of a hydrocarbon solvent. Copolymerization of ethylene and (1) α-5-1 olefin having 5 to 15 carbon atoms is carried out to produce a copolymer of 1 to 70 fi based on the total amount of the final copolymer.

Second stage: Remove the hydrocarbon solvent from the copolymer.

3rd stage: Ethylene and (
b) Copolymerizing an α-olefin having 3 to 4 carbon atoms.

The present invention relates to a method for producing a copolymer characterized by the following.

The present invention will be explained in more detail below.

The first feature of the present invention is to minimize the amount of expensive long-chain α-olefin used and to produce high-quality copolymers. 1, the superiority of the present invention is clear.

The second feature of the present invention is that MI, which is difficult to produce by solution polymerization,
It is possible to produce a copolymer with a molecular weight of 0.5 or less.

A third feature of the invention is the production of the low density copolymer as a high bulk density powder, which
This eliminates the process of pelletizing the copolymer, which requires extra energy, and enables bulk shipment of the powder.

The fourth feature of the present invention is that a copolymer with a narrow molecular weight distribution can be produced with high activity, and this can be achieved for the first time by using a catalyst suitable for the present invention as described below. A. If a specific catalyst is used, it is also possible to produce a co-311 complex with a wide molecular weight distribution. Furthermore, it is also possible to produce a copolymer with a wide molecular weight distribution by controlling the synthesis conditions of 71-j in the first and third stages.

The α-olefin used in the present invention will be explained.

(a) The α-olefin having 3 to 4 carbon atoms is propylene, 1-butene, or a mixture thereof, and 1-butene is preferably used.

(b) As an α-olefin having 5 to 15 carbon atoms, U, Example Itf, i-hentene, 1-hexene, 1-cene, 1-undecene, l-dodecene, 1-tritecene, 1-tetradecene, 1 -Pentadecene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 4,4-dimethyl-1-pentene, vinylcyclocethane, etc., or mixtures thereof are used.

In the present invention, as a first step, copolymerization of ethylene and (b) an α-olefin having 5 to 15 carbon atoms is carried out by suspension polymerization in the presence of a hydrocarbon solvent.
Propane, n-butane, i-butane, n-pentane, i
- Pentane, n-hexane, i-hexane, n-hebutane, etc. or mixtures thereof are used. Preferably,
Hydrocarbon compounds having 3 to 6 carbon atoms are used. The polymerization temperature is from 0 to 120°C, preferably from 10 to 90°C, and the polymerization pressure is from normal pressure to Zoo Kg/crAG.

Molecular weight can be adjusted by □ addition of organic compounds that easily cause chain transfer, polymerization temperature, addition of α-olefin, etc., but by introducing hydrogen into the polymerization system, it is possible to effectively control the molecular weight. The use of α-olefin (1)) in which the adjustment of h) is carried out is 1.71”, based on ethylene, 1 to 250 mo1%, preferably 1 to 200 moles
mot%.

In the present invention, the amount of copolymer produced in the first stage is
7.1 to 70% by weight of I based on the total amount of the final copolymer, preferably 10 to 65% (1% by weight is necessary to achieve the purpose of the present invention. The density of the copolymer &j: is preferably in the range of 0.925 to 0.955, preferably 0.935 to 0.950.

After the suspension polymerization, the hydrocarbon solvent is removed in the second stage, and then the gas phase 1 reaction is carried out in the third stage.

Hydrocarbon solvents can be removed by filtration, centrifugation, or
Methods such as distillation of the solvent by heating or reduced pressure are used.

As the third stage, ethylene and (a) α-olefin having 3 to 4 carbon atoms are copolymerized in a gas phase without a solvent, but at this time, the suspension polymerization in the first stage is The first stage may be carried out in the same reactor as -1, f? :,
It is also possible to carry out the suspension polymerization in a plurality of reactors and then carry out the gas phase polymerization in the third stage in a separate reactor or in a plurality of reactors.

In the gas phase polymerization, the polymerization temperature is 20 to 110'C, preferably 40 to 900C, and the polymerization pressure is normal pressure to 100K/cn.
In the range of lQ, new ethylene and α-olefin (a”
This is done by introducing l. Adjustment of molecular weight is 1
Although it is possible to adjust the polymerization temperature and the amount of α-olefin added, the molecular weight can be effectively controlled by introducing hydrogen into the polymerization system.

The amount of α-olefin (a) used is 1 to 1 to ethylene.
The range is 250 mot% and the stem thickness is 5 to 200 mot%.

In gas phase polymerization, it is preferable not to add a new catalyst, or to add only the organometallic compound [B]. When a new solid catalyst (A) is added.

The physical properties of the copolymer deteriorate, making the stem unsuitable.

The catalyst used in the present invention is composed of [A] a solid catalyst containing at least magnesium, titanium, and halogen atoms, and [B] an organometallic compound.

The solid catalyst [A] is a reaction product of an organomagnesium compound and a halogen-containing titanium compound or a halogen-containing titanium compound and a vanadine compound or/and a zircon compound, an organomagnesium compound and a halogenating agent (excluding titanium, vanadine, and zircon compounds). and a reaction product of a titanium compound or a titanium compound and a vanadine compound or/and a zircon compound A halide containing at least one selected from magnesium or magnesium and calcium, boron, aluminum, silicon, and zinc, hydroxide A reaction product of a halogen-containing titanium compound, a halogen-containing titanium compound, a vanadine compound or/and a zircon compound, etc. is used.

Organometallic compound (BE: AL (C2Hg)
m.

kt (C8H7)s, At(C4H,)s,
At(C5H,1), , A1. (c, 9).

At(Cs HIT) At(C1oHn) Trialkylaluminum such as s, n(C2Hs), HlAt
Alkylaluminum hydrides such as (i-C4H,)2H, At(C,Hg), CL, Az(C2H5
) Ca2. Az(i-C,I(,)Ca2.Az(
Alkylaluminum halides such as C2H,), Br, A, L (C2Hs)z(OC2■J5), AA(
Alkoxyalkyl aluminum such as i-C4T-T9)2 (QC,Hg), At(02H,), (O8i
E(CH.

C2Hg ), kA (x C4Hg )1 ・(
OSt (CHB)1i'-CaH,) siloxyalkyl aluminum, isoprenyl aluminum,
Reaction product of noalkyl aluminum such as myrcenyl aluminum and conjugated diene, Zn (CgHs)z,
Zn (c4i-(,)!!, Zn (Cm Hu)
! -Zn (C8HIT) t, Zn (C,H,
) (n-C5I-17), Z”(CsHs)i, Zn
Organozinc compounds such as (C,H7)(QC,H,), general formula MαMg%
Body surface m Group I to Group 1 [Group 1 metal atoms, α-p, q
-r is a number greater than or equal to 0, p1q=mα+2,0≦q/
(, +s) < 2, m is the valence of M,
R' is one kind or a mixture of two or more kinds of hydrocarbon groups having 1 to 20 carbon atoms;
mixture of more than one species, D represents an electron-donating organic compound)
Organomagnesium compounds represented by the following and mixtures thereof are used.

In order to fully exhibit the effects of the present invention, the performance of the catalyst is important. Specific catalysts suitable for the production method of the present invention include, for example, the general formula MαMgR′pX, (in the formula M
is a metal atom of Groups 1 to 2 of the periodic table, α, p-q-r
is a number greater than or equal to O.

p+q=mα+2,0≦q/ (,2+1)<2
The relationship is as follows: valence of 1 m x M, R' is one type or a mixture of two or more hydrocarbon groups having 1 to 20 carbon atoms, X is a hydrogen atom or oxygen, nitrogen t. This is a negative group containing a sulfur atom; 141i also works, 2
A magnesium compound soluble in a hydrocarbon solvent and a halogen-containing titanium compound or a halogen-containing titanium compound and vanadation.

Systems using compound reactants as solid catalysts [A] (Japanese Patent Publication No. 52-36788, Japanese Patent Publication No. 52-36790, Japanese Patent Publication No. 52-36791, Japanese Patent Publication No. 52-36795, Japanese Patent Publication No. 52-36796, Special Publication No. 52-36914,
Special Publication No. 52-36915, Special U1” 1982-8799
0-bow, q'J JP-A No. 54-66391, 18- JP-A No. 54-66392, etc.), 2.These solid catalysts [A] and halogen-containing aluminum and/or
Or a system using a reactant of a titanium compound (Japanese Patent Publication No. 53-
No. 6019, JP-A-51-148785), general formula MαMgR6X, .Dr (in the formula M, R+', X, α
, p, and q have the above-mentioned meanings; D represents an electron-donating organic compound, and r represents a number of 0 or more; a magnesium compound soluble in a hydrocarbon solvent and a halogenating agent (
A system using a reaction product of a titanium compound (excluding titanium, vanadine, and zircon compounds) and a titanium compound or a reaction product of a titanium compound and a vanadine compound as a solid catalyst (A)
No. 40696, JP-A No. 53-57195, etc.)
A solid formed by reacting a titanium compound or a titanium compound with a vanadine compound or a zircon compound and an organometallic compound in the presence of a reactant of the general formula MaMg tag X, Dr and a halogenating agent (excluding titanium, vanadine, and zircon compounds). The catalyst system used as the solid catalyst [A] (described in Japanese Patent Application No. 56-20074, Japanese Patent Application No. 56-35205, and Japanese Patent Application No. 56-39655) is a mixture of titanate ester oligomer 14- and titanium halide. After thermal decomposition, the general formula M
ctM, seagull Xq-D, (in the formula M, R', X, D, α, p
.

Examples include a system (described in JP-A-55-38806) in which a solid catalyst (A) treated with q and r has the meanings given above) is used.

Catalyst components [A] and [n) may be added into the polymerization system under polymerization conditions12 or may be combined in advance prior to polymerization. The ratio of the two components to be combined is
[A] 1y to D [13:] to 0.1 rnmot ~ 5
00 mmot, light and heavy weight 1 mmol ~ 300
Used in the mmot range.

Polymers containing many double bonds in the polymer main chain or side chains can also be produced by carrying out polymerization in the presence of a small proportion of conjugated or non-conjugated diene.

Examples of the present invention are shown below, but the present invention is not limited to these examples in any way.

In these examples, MI stands for tart index, and the temperature was 190°C according to ASTM D-1238.
This was measured under a load of 2.16K9.

PR means the quotient obtained by dividing the value measured at a temperature of 190°C and a load M of 21.6 K, y by MI, and is 1 of the molecular weight distribution scale.
The lower the value, the narrower the molecular weight distribution. The catalytic activity is expressed by the amount of copolymer produced from the solid catalyst (A) IS'M.

Example 1 Capacity 2501 with dropping funnel and water-cooled reflux condenser installed
Oxygen and moisture inside the 11 t flask were removed by nitrogen substitution, and 1 mot/ml of trichlorosilane was added under nitrogen atmosphere.
1 of heptane solution 25w4 and heptane 25% were charged and the temperature was raised to 70°C. Next, kt6.02Mg (C
+HsL,yy (n C4HIL,?7 (n C4
H9) 0.77 (On C4H9L, 5221.5m
50 tL of heptane containing mot was weighed into a dropping funnel, and added dropwise over 2 hours while stirring at 70°C.

As a result, the reaction solution became a white suspension. Cool to room temperature, let stand, remove supernatant by decantation, wash twice with 50tRt hebutane, add Hebutane 7 to make 00*0 liquid volume, (jD reaction solution 74) After introducing 1.4 mmol of titanium chloride and 3.2 mmot of diethylaluminium chloride and carrying out a reaction at 60°C for 2 hours, the solid catalyst was isolated, washed with heptane, and then dried.

50 μm of this solid catalyst [A] and 2 mmot of triynebutylaluminum were introduced together with 6 tons of dehydrated and degassed isobutane into a 10-t autoclave whose interior was dehydrated and degassed. Next, 1.7 mot of 1-octene was introduced, and the internal temperature of the autoclave was raised to 70°C.
Kg/cd-(Jx pressure was increased, and ethylene was introduced to bring the total pressure to 14 kg/-・G. By replenishing ethylene, the pressure of 14 Kq/c11-G was maintained and the ethylene was increased to 7.
30 mots were polymerized. The copolymer produced here is MI
1.8, and the density was 0°942. This suspension was then transferred to a 50 ton fluidized bed autoclave, and the isobutane was removed by purging. The internal temperature of the autoclave was set to 70°C, and 17 cnl of a mixed gas of ethylene:1-butene:hydrogen in a molar ratio of 1:0.15:0.05 was added.
Polymerization was carried out for 10 minutes at a pressure of 10 Kr/c+J-G while introducing at a rate of 2,120 Kr/sec to obtain a copolymer powder of 2,120 Kr/sec. MI of copolymer is 2.11, density 0.920, FR
24, bulk density 0.39 f/g! , the melting point was 121°C. After making this copolymer into a pellet shape, the die diameter was 50.
A film with a thickness of 30 μm was formed using a 11I+IIφ inflation film molding machine-117 (Ono Seisaku Shinsei 30, ψ extruder). The characteristics of this film are shown in the surface finish.

Example 2 Oxygen and moisture inside a 500 ml flask equipped with two dropping funnels were removed by dry nitrogen substitution, 160-hbutane was added, and the flask was cooled to -5°C. Next M
g(C2H5) (n-C4H0)(n c4I(9I
, t ) o, heptane 8 containing os40 mmot
80 ml of heptane containing 0- and 60 mrnot of titanium tetrachloride. were weighed into each dropping funnel, and heated to -5°C.
Both components were added simultaneously over 2 hours while stirring, and the aging reaction was further carried out at 5°C for 1 hour. The produced solid catalyst was isolated, washed with heptane, and then dried.

This solid catalyst [A:] 5s and triethylaluminum, 5mmol, were introduced together with 6L of dehydrated and degassed isobutane into a 10t autoclave whose interior was dehydrated and degassed.

Next, 1.2 mot of 4-methyl-1-pentene was introduced,
The internal temperature of the autoclave was raised to 70°C. 10 hydrogen
．． It was pressurized at a pressure of 7 V'c-G, and ethylene was introduced to bring the total pressure to 14 Ky/V'G. By supplying ethylene, 16 mot of ethylene was polymerized while maintaining a pressure of 14 Kv/ctl-G. -6 The suspension was then transferred to a 50 t fluidized bed autoclave, and the isobutane was then removed. A small amount of the 111 compound was taken out and the MI and density were measured, and the MT was 2.3.
The density was 0.940. Inside the autoclave 1 to 7
The temperature is 0°C, and the molar ratio of ethylene = 1-butene: hydrogen is 1:
While introducing a mixed gas of 0.19:0:09 at a rate of 15 ozt/sec, a copolymer powder of 2380 f was obtained by combining at a pressure of 10 to 9/g for 1.5 hours.

Copolymer MI is 1.8, density Q is 924, F'R35
, the density was 0.41 t/-.

The copolymer was formed into a film having a thickness of 30 μm under the same conditions as in Example 1, and its properties were measured. Show the results to the tablework.

Comparative Example 1 Capacity 500 with dropping funnel and water-cooled reflux condenser
Oxygen and moisture inside the ml flask were removed by nitrogen substitution, and 200 mmol of titanium tetrachloride was added under a nitrogen atmosphere.
7200 mg of hepta containing t was charged.

Add 250ml of diethylaluminum chloride to the dropping funnel.
200 pieces of heptane containing not were weighed out and added dropwise at 30° C. over 1 hour while stirring, then the temperature was raised to 70° C., reaction was carried out for 2 hours, and the solid catalyst was isolated, washed with heptane, and then dried.

This solid catalyst (A,) soo■, triethylaluminum 600 mmot and 1-butene 2. Suspension polymerization was carried out in the same manner as in Example 1 except that Omot was used, and 30 mat of ethylene was polymerized. Subsequently, ethylene: 1-
Butene:hydrogen molar ratio 1: 0.23: 0.02
Gas phase polymerization was carried out in the same manner as in Example 1 except that a mixed gas of 240Of was used to obtain a copolymer powder of 240Of. The copolymer had an MI of 3.2, a density of 0.923, a FR of 39, a bulk density of 0.25, and a melting point of 117°C. A film with a thickness of 30μ was formed using the copolymer under the same conditions as in Example 1,
The characteristics of this were measured. Show the results to the tablework.

Comparative Example 2 Same as Example 1 except that 80 mol of the solid catalyst [:A] synthesized in Example 1, 3 mmot of triethylaluminum, and 5 mol of Dialene 124 (manufactured by Mitsubishi Kasei Corporation, a mixture of 1-dodecene and 1-tetradecene) were used. Polymerization was carried out in the same manner for 1 hour. In the middle of polymerization, the stirring power increased and smooth stirring became difficult, and the cooling effect of the jacket deteriorated, causing disturbances in the temperature control inside the reactor. A polymer bale of 1350 tf of bulk copolymer was obtained.

This copolymer had an MI of 6.7 and a density of 0.938.

Table 1 Examples 3 to 8 Solid catalyst [A] 50 to synthesized in Example 1 and Toli 21
- Polymerization was carried out in the same manner as in Example 1, except that 2.8 mmc) L of subbutylaluminum was used and the conditions shown in Table 1 were used to obtain the results shown in the table.

Examples 9-10 Capacity 250- with dropping funnel and water-cooled reflux condenser installed
Oxygen and moisture inside the flask were removed by nitrogen substitution, and A4+, 15 Mg(C2N(s)o, 45(n-C)
4Hg) Heptane 50- containing 250 mmot
was charged and the temperature was raised to 80°C. Next, 50 mmol of heptane containing 50 mmot of dichloromethylsilane was weighed into the dropping funnel, added dropwise over 30 minutes while stirring at 80° C., and further stirred at this temperature for 1 hour. The white solid that formed was isolated and dried. After reacting 2 tons of this white solid with 40 ml of titanium tetrachloride at 130° C. for 2 hours, the solid was isolated, washed with heptane, and then dried. This solid catalyst [A':] 100
Polymerization was carried out in the same manner as in Example 1 except for using 8.4 mmoA of triisobutylaluminum and 8.4 mmoA of triisobutyl aluminum, and the results shown in the table were obtained.

=22-

Claims (1)

[Scope of Claims] 1. 2fHfj or more selected from the following groups: 1. Ethylene, (a) α-olefins having 3 to 4 carbon atoms, and (b) α-olefins having 5 to 15 carbon atoms. α−
The olefin is combined with [A,) a solid catalyst containing at least magnesium, titanium and halogen atoms and (13
) Copolymerized in the presence of an organometallic compound to form a copolymer! First stage: θ ~ in the presence of a hydrocarbon solvent
At 120°C, ethylene and (b) α having 5 to 15 carbon atoms
- Copolymerizing the olefin to produce a copolymer of 1 to 70% by weight based on the total amount of the final copolymer. Second stage: removing the hydrocarbon solvent from the copolymer. 3rd stage: Ethylene and (
a) Copolymerizing an α-olefin having 3 to 4 carbon atoms. A method for producing a copolymer, characterized by: