JPS5840307A - Production of copolymer - Google Patents

Abstract

PURPOSE:To reduce the amount of an expensive long-chain alpha-olefin used and at the same time to produce a high-quality, low-density copolymer, by subjecting ethylene and an alpha-olefin to vapor-phase polymerization in the 1st stage and to suspension polymerization in the 2nd stage in the presence of a Ziegler catalyst under specified conditions. CONSTITUTION:Ethylene and an alpha-olefin are copolymerized in two stages in the presence of (A) a solid catalyst containing Mg, Ti and a halogen atom and (B) an organometallic compound. Namely, (i) in a vapor phase, ethylene and a 3-4 C alpha-olefin are polymerized at about 20-110 deg.C under atmospheric pressure to 100kg/cm<2>G to form 10-80wt%, based on the total weight of the final copolymer, copolymer of density about 0.935-0.96, and subsequently (ii) ethylene and a 5 C or higher alpha-olefin are polymerized at about 0-120 deg.C under atmospheric pressure to 100kg/cm<2>G in the presence of a hydrocarbon solvent to form a low- density (<= about 0.92) copolymer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel copolymer in which ethylene and two or more α-olefins are copolymerized. This method involves copolymerizing ~4 α-olefins and then copolymerizing ethylene with an α-olefin having 5 to 15 carbon atoms in the presence of a hydrocarbon solvent.

Conventionally, a Teak 2-type catalyst has been used to convert ethylene and other α
- It is possible to control the density of an ethylene copolymer by copolymerizing olefins to produce medium- to low-density polyethylene, which is the subject of a Canadian patent! ! It was well known in No. 4211. Moreover, the low-density polyethylene obtained from K by copolymerizing ethylene and other α-olefins using a Ziegler type catalyst has superior mechanical properties such as tensile strength compared to low-density polyethylene produced by the bulk pressure method. ,
It also has an excellent melting point of 10 to 12°C higher. Furthermore, this method is extremely effective when using α-olefins having 5 or more carbon atoms. However, α-olefins having 5 or more carbon atoms are industrially expensive and can be produced in small amounts, resulting in problems such as increased cost of the copolymer and limited production.

On the other hand, methods for producing copolymers of ethylene and other α-olefins include a suspension polymerization method in which polymerization is carried out in suspension at a temperature below the melting point of the copolymer in a hydrocarbon solvent, and a suspension polymerization method in which polymerization is carried out in a suspended state in a hydrocarbon solvent at a temperature below the melting point of the copolymer. , a solution polymerization method in which polymerization is carried out in a solution state at a temperature higher than the melting point of the copolymer, and substantially in the absence of a solvent, 12
A gas phase polymerization method in which polymerization is carried out in a gas phase at a temperature of 0° C. or lower is known.

However, when copolymerizing ethylene and other α-olefins by suspension polymerization, the bulk density of the copolymer increases because the amount of copolymer soluble in the solvent increases as the density decreases. This tends to cause severe fouling on the reactor wall, as well as increase in viscosity and stickiness of the polymerization system. If the copolymer density gO is 940 or higher, there will be almost no trouble in operation, but if the copolymer density is lowered to 0.920 fi, industrial operation becomes difficult.

However, in solution polymerization, the copolymer is dissolved and the operation is performed in a solution state, so the above problems do not occur, but since a highly viscous solution is stirred, the melt index (
The lower the high molecular weight copolymer (hereinafter abbreviated as MI), the lower the concentration of the solution must be.
It is very difficult to produce high molecular weight copolymers with a molecular weight of 5 or less.

Moreover, solution polymerization has the disadvantage that if the copolymer is obtained as a powder, it cannot be sharpened.

On the other hand, in gas phase polymerization, it is relatively easy to produce a copolymer with low density and MT, but because it is in a gas phase, α-olefins with a high boiling point and 5 or more carbon atoms can be produced. It is industrially very difficult to use. On the other hand, in suspension polymerization and solution polymerization, there are basically no restrictions on the selection of the type of α-olefin.

The inventors of the present invention have completed the present invention as a result of intensive research to solve the above-mentioned problems. can easily produce copolymers of
and α-olefin having 3 to 4 carbon atoms and 5 to 1
By using a combination of five α-olefins,
A copolymer produced by reducing the amount of expensive α-olefin having 5 to 15 carbon atoms has performance equivalent to or better than a copolymer of ethylene and α-olefin having 5 or more carbon atoms. That is surprising.

That is, the present invention provides ethylene and (a) a carbon atom having 3 carbon atoms.
~4 α-olefins, (b) two or more α-olefins selected from each group of α-olefins having 5 to 15 carbon atoms, and containing at least magnesium, titanium, and halogen atoms. Copolymerization in the presence of a solid catalyst and a spherical organometallic compound to produce a copolymer. 1st step: ethylene and (a) having 3 to 4 carbon atoms in a gas phase substantially in the absence of a solvent. Copolymerization of α-olefins is carried out, and 10 to 80% by weight of the total amount of the final copolymer is copolymerized.
〇The second stage for producing a copolymer is characterized by copolymerizing ethylene and (b) an α-olefin having 5 to 15 carbon atoms at 0 to 120°C in the presence of a double vertical hydrogen solvent. This relates to a method for producing a copolymer.

The present invention will be explained in more detail below.

The first feature of the present invention is that it is possible to minimize the amount of expensive long-chain α-olefin used and still produce a high-quality copolymer. The superiority of the present invention is clear.

The second feature of the present invention is MI, which is difficult to produce by solution polymerization.
It is possible to produce copolymers with O,5 or less.

The third feature of the present invention is that a low-density copolymer can be produced as a powder with good powder characteristics. This allows for shipment as is.

As mentioned above, it is difficult to produce a low-density copolymer by suspension polymerization, but if it were possible, various attempts have been made to easily produce a powdered copolymer. for example,
JP-A-51-52487, JP-A-52-121689
No., Japanese Patent Publication No. 52-12408? This method involves prepolymerizing a small amount of ethylene and then copolymerizing ethylene and α-olefin. However, in this method, the solvents that can be used are very limited, and the polymer produced by prepolymerization has a high density and high molecular weight, which can cause gel or stickiness in the product during film formation, rotational molding, etc. That's it. On the other hand, this characteristic can also be achieved by a method (% Application No. 105447/1983), which has been invented by the present inventor, in which suspension polymerization is followed by gas phase polymerization.

However, in this method, when transitioning from suspension polymerization to gas phase polymerization, it is necessary to remove the solvent, so the catalyst may be deactivated in this step, and the solvent removal may be insufficient, causing problems in gas phase polymerization. There is a problem in that there is a high possibility that this will occur.

In the present invention, under the conditions detailed below, after gas phase polymerization is performed in the first stage, suspension polymerization is performed in the second stage.
．． 9 jO copolymer powder can also be produced.

The fourth feature of the present invention is that a copolymer with a narrow molecular weight distribution can be produced with high activity, which is achieved for the first time (by using a catalyst suitable for the present invention as described below). . Furthermore, if a specific catalyst is used, it is also possible to produce a copolymer with a wide molecular weight distribution. Furthermore, by controlling the polymerization conditions in the first and second stages, it is also possible to produce a copolymer with a wide molecular weight distribution.

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

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

佽) As an α-olefin having 5 to 15 carbon atoms,
For example, 1-pentene, 1-hexene, 1-heptene,
1-octene, 1-nonene, 1-decene, 1-undene, 1-dodecene, 1-tritecene, 1-tetradecene, 1-pentadecene, 5-methyl-1-butene, 5-methyl-1-pentene, 4-methyl-1-pentene, 4.
4-dimethyl-1-pentene, vinylcyclocethane, or mixtures thereof are used.

In the first stage of the present invention, copolymerization of ethylene and (8) an α-olefin having 3 to 4 carbon atoms is carried out in a gas phase substantially without a solvent, and the polymerization temperature is 20 to 110°C. °C,
Preferably 40 to 90°C, polymerization pressure is normal pressure to 10Q
It is carried out in the range of kg/cd・G.

Although it is possible to control the molecular weight, the polymerization temperature, and the amount of α-olefin added, it is effectively carried out by introducing hydrogen into the polymerization system.

The amount of α-olefin (a) used is 1 for ethylene.
~250 mol, preferably 5-200 mol91G
is within the range of

In the present invention, the amount of copolymer produced in the first stage is 10 to 80% by weight, preferably 2% by weight, based on the total amount of the final copolymer.
5 to 65 weights is necessary for rounding to achieve the purpose of the invention. Also, the density of the copolymer produced in the first stage is O,? 35-0.960, preferably 0.9
40~O1? It is important that it is in the range of 55.

In suspension polymerization, as mentioned above, it is not easy to produce a density of 0.940 or less, and various manufacturing restrictions arise. ? A value of 20 or less is almost industrially impossible. However, the present invention produces a copolymer powder with a controlled density in the first stage of gas phase polymerization, and then performs suspension polymerization to achieve a density of 0, which was previously considered impossible.
．． ? 20 or less can be produced by suspension polymerization.

The reason for this is still unclear, but the highly dense copolymer produced during gas phase polymerization plays a role like a shell on the surface of each particle, and the less dense copolymer produced inside during suspension polymerization acts as a shell. This is thought to be the ninth factor that prevents the copolymer from dissolving in the solvent. Furthermore, the amount of copolymer produced in the first stage and the second stage,
It has the characteristic that the difference in density between the copolymers at each stage is small, which prevents the formation of gels and lumps in the finished product during rounding, film forming, and rotational molding.

After gas phase polymerization, in the second stage, ethylene and α-olefin having 5 to 15 carbon atoms are copolymerized in a suspended state in the presence of a hydrocarbon solvent, but the first stage is an autoclave equipped with a stirrer. If so, the polymerization may be carried out by introducing a solvent in the same reactor, or the first stage may be carried out in a gas phase polymerization in one or more reactors, and then the second stage may be carried out in a separate single or plural reactor. Nine, it is possible to carry out suspension polymerization in multiple reactors.

Suspension polymerization uses propane as a hydrocarbon solvent, n-butane, i-7'tane, n-pentane, i-pentane, n-
A mixture of hexane, i-hexane, etc., preferably a hydrocarbon compound having 3 to 5 legome atoms, is used at a polymerization temperature of 0 to 0.
120℃, preferably 10 to 90℃, polymerization pressure is normal pressure to
It is carried out in the range of 1ookg/c11・G.

Molecular weight can be adjusted by adding organic compounds that are likely to cause chain transfer, polymerization temperature, amount of α-olefin added, etc., but molecular weight can be effectively adjusted by introducing hydrogen into the polymerization system. will be implemented.

The amount of α-olefin (b) used is 1 to 1 per ethylene.
250 moles, preferably in the range of 5 to 200 mots.

In suspension polymerization, it is preferable to carry out the suspension polymerization without adding a catalyst or adding only the organometallic compound (2). It is not preferable to add a new solid catalyst because it deteriorates the physical properties of the copolymer.

The catalyst used in the present invention consists of a solid catalyst and a round organometallic compound containing at least magnesium, titanium, and halogen atoms. A reaction product of a vanadine compound and a zircon compound, a reaction product of an organic magnesium compound and a halogenating agent (excluding titanium, vanadium, and zircon compounds) and a titanium compound, or a titanium compound and a vanadine compound or/and zircon A reaction product with a compound, a halide, hydroxide, oxide, carbonate, alkoxide, etc. containing at least one selected from magnesium or magnesium and calcium, boron, aluminum, silicon, zinc, and a halogen-containing titanium compound or Halogen-containing titanium compound and vanadine compound or/
and reactants of zircon compounds are used.

As the organometallic compound (5), At(CaHe)s
, At(CsHJs, AJ!(C*1'1s)s %
At(Cs Hat)s% At(C@Hti)
s % At(Ca)I+y)s %A/-(CIl
l H! I) Trialkylaluminum such as a, A
t(C,H,)! Alkylaluminum hydride such as H, At'(i-C4H,), H, At'(CtHs
)*Ct, At(CtHs) CI4, At(j C4
HI) C4, alkylaluminum halide such as At(CaHe)tBr, A-4(CtHs)t(OC*
Hs'), Al'(i C4H11)1(QC4He
), etc., alkoxyalkylaluminum, kl (C
xHs) * (081HcH1ct Ha ), At(
'CaHe)t・(O8i (CHs)*'-Ci
fin (
C,H,), ,Zn (C,H,), ,Zn (C
sHts )t, zn (CaHn)t, Zn (C@
H@) (n-C1Hy), zn (CllMB)
1, "(CmHd (OeiH*) fathom organozinc compound, general formula MaMgR'pX, Dr (where M is a metal atom of group gI to group II of the periodic table, α, p, q, r are 0 or more , p+ Q=mα+2.0≦q/(α+1)<2, where m ij is the valence of M, and R′ is Ill or Ill of an aspect ratio hydrogen group having 1 to 20 carbon atoms. An organomagnesium compound represented by a mixture of Fi2m or more; Mixtures of these 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, those having the general formula Ma'g''p
a Q e ' is a number greater than or equal to 0, and p+q=mα+2.
It has the relationship of 0≦q/(α+1)×2, m FiM valence Bl is a mixture of t, <Fizs or more of hydrocarbon groups having 1 to 20 carbon atoms, x#'i hydrogen 1 of the atoms or negative groups containing oxygen, nitrogen or sulfur atoms
A system (q#, Kosho 52-34788, Special Publication No. 52-36790, Special Publication No. 52-36791, Special Publication No. 52-316795, Special Publication No. 52-56796, Special Publication No. 52-56914
No., Special Publication No. 52-34915, Japanese Patent Publication No. 55-8799
No. 0, JP-A-54-66391, JP-A-54-61a
S92 etc.), a system using a reaction product of these solid catalysts and a halogen-containing aluminum and/or titanium compound (Japanese Patent Publication No. 53-401?, % open 5
1-148785), general formula 1! iaMgR;
In a hydrocarbon solvent represented by X, Dr (in the formula, M, R', A system using a reaction product of a soluble magnesium compound and a halogenating agent (excluding titanium, vanadine, and zirconium compounds) and a titanium compound or a reaction product of a titanium compound and a vanadine compound as a solid catalyst prisoner (%Kaikai No. 53-40696) , described in JP-A No. 53-57195, etc.), to the general formula '! iaMg
A solid obtained by reacting a titanium compound or a titanium compound with a vanadine compound, a zircon compound, and an organic compound in the presence of a reactant of R'pX, Dr and a halogenating agent (excluding titanium, vanadine, and zircon compounds) is solidified. Catalyst system used as catalyst prisoner (Japanese Patent Application No. 56-20074 1,
(described in Japanese Patent Application No. 56-35205 and Japanese Patent Application No. 56-59655), after thermal decomposition of a mixture of titanate ester oligomer and titanium halide and after death, the general formula MaMgR'px
, D, (where M, R', X1D1α, 9% qS'F
Examples include a system (described in %Kokai No. 55-38806) in which a solid catalyst treated with the above-mentioned method is used as a solid catalyst.

Catalyst components (1) and (1) may be added to the polymerization system under polymerization conditions, or may be combined in advance prior to polymerization. Furthermore, in the presence of hydrocarbon ° solvent, solid catalyst 1f
It is also possible to prepolymerize 0.1 to 509 ethylene per ethylene and introduce it into a reactor after distilling off the solvent to carry out gas phase polymerization. Further, the ratio of the two components to be combined is used in the range of (6) per I201f to 0.1 to 500rrII'n021, preferably 1 to SOOmmol-.

By carrying out polymerization in the presence of a small amount of conjugated or non-conjugated diene, it is also possible to produce a monomer containing many double bonds in the main chain and side chains of the polymer.

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

In addition, in these examples, Ml represents melt index, and the temperature was 190°C according to A8TM D-1258.
, measured under 90 conditions at a load of 2.16. F
R means the nine quotient obtained by dividing the value measured at a temperature of 190°C and a load of 21.6 ky'' by MI, and is one of the measures of molecular weight distribution, and the lower the value, the narrower the molecular weight distribution. The catalytic activity is expressed as the amount of copolymer produced using the solid catalyst rAJ1.

Example 1 Capacity 250- with dropping funnel and water-cooled reflux condenser installed
Oxygen and moisture inside the flask were removed by repeated displacement, and trichloro)resilane 1 mat was added under a nitrogen atmosphere.
30-liter of hebutane solution and 20-liter of heptane solution were charged, and the temperature was raised to 70°C. Next K.

Am,,MgfC,%%,,(IS-C1H,,%,,
(On-C,H,), 50 mmol of heptane containing 20 mmot was weighed into a dropping funnel and added dropwise at 80 C over 1 hour while stirring. As a result, the reaction solution became a white suspension. The mixture was cooled to room temperature and allowed to stand, the supernatant liquid was removed by decantation, and the mixture was further washed three times with 50-molecular hebutane, and then hebutane was added to bring the liquid volume to 100-100°. Add 1.21 mm of i-butoxytitanium trichloride to this reaction solution.
qt and isobutylaluminum dichloride 4.84 m
After introducing mot and carrying out the reaction at 60C for 4 hours, the solid catalyst was isolated, washed with heptane, and then dried.

A 40-ton autotalebe Vc manufactured by Kai with a stirrer whose interior had been dehydrated and degassed, a solid catalyst tA110Oa9, and 5 mmol of triethylaluminum were charged. Next, the internal temperature of the autoclave was raised to 175 C, and a mixed gas of ethylene = 1-butene: hydrogen in a molar ratio of 1: 0.18: 0.06 was introduced at a pressure of 15 kg/wound"·G. ethylene 180
0) was polymerized. This copolymer had an MI of 0.56 and a density of 0.946. Then, i-butane 25t, 1-
2.6 mols of octene) and 0.2 mmottm of ethylaluminum, and the temperature was raised to 65C. Hydrogen was pressurized at a pressure of 9.5 kg/-.G, and ethylene was introduced to bring the total pressure to 14 kg/-.G. While maintaining the pressure of 14 kg/1m"・G by replenishing ethylene,
Ethylene 1900) was polymerized. M of the obtained copolymer
I is 5.1, FR1$3, density 0,921.

The bulk density was o, s 8 t/d, and the melting point was 120C.

After making this copolymer into pellets, the die diameter was 50 mm.
A film with a thickness of 30 μm was formed using an inflation film molding method (50 snφ extruder newly manufactured by Ono Seisakusho).

The properties of this film are shown in Table 1.

Example 2 Two dropping funnels were installed and oxygen and moisture inside a 9-volume 500-volume flask were removed by dry nitrogen replacement.
Add 0-hebutane and cool to -20C.
80 mm of heptane containing t and 40 mm of titanium tetrachloride
Weigh out 80 kg of heptane containing 200 ml of heptane into each dropping funnel, add both components simultaneously under stirring at -20 C for 4 hours, isolate the solid catalyst produced, and wash with heptane. Dry and mourning.

This solid catalyst (A1100 Misaki and triethylaluminum S mmot) was charged into a 40t autoclave equipped with a chi-type stirrer whose interior had been dehydrated and degassed.Next, the internal temperature of the autoclave was raised to 75C, and a mixture of ethylene:1-butene:hydrogen was added. Mixed gas with a molar ratio of 1:0.20:0.08 is mixed with 15
Introduced at a pressure of kl/e1m"・G, ethylene 2700
Next, i-butane 251, Daikiren 124C (mixture of 1-dodecene and 1-tetradecene) 1,4 mot and trioctylaluminum 0.35 mmot were added, and the temperature was raised to 65 CK. λ゛, the basics? , by pressurizing at a pressure of 8 ky/au-G, introducing ethylene to bring the total pressure to 14 ky/as"・G, and replenishing 9 ethylene. While maintaining the pressure of 14 ky/au-G, 800 tons of ethylene was polymerized. M of the obtained copolymer
I is 2.8, PR is 34. Density 0.922, bulk density 0.
56 t/ml, melting point is 120C, 9. This copolymer was made into a pellet shape and after death, the thickness was 30j as in Example 1.
A film of No. 1 was formed. The properties of this film are shown in Table 1.

Comparative Example 1 Capacity 50 with dropping funnel and water-cooled reflux condenser
0wt? Oxygen and moisture inside the flask were removed by nitrogen substitution, and 200 mmo of titanium tetrachloride was added under a nitrogen atmosphere.
200 m of heptane containing t was charged. 200 mm of heptane containing 250 mmot of diethylaluminium chloride was weighed into the dropping funnel and added over 1 hour under stirring at 30C.

The temperature was raised to 70C, the reaction was carried out for 2 hours, and the solid catalyst was isolated, washed with heptane, and then dried.

Ethylene 230 mg was prepared in the same manner as in Example 1, except that 1700 mg of this solid catalyst IA, 45 mmol of triethylalbanium, and a mixed gas with a molar ratio of ethylene:1-butene:hydrogen of i: 0.22: 11.06 were used.
0t was polymerized. Next, 1100 mol of ethylene was prepared in the same manner as in Example 1 except that 1.2 mot of 1-butene was used.
) was polymerized. The MI of the obtained copolymer was 1.4. F.R.
57, density 0.926, bulk density 0.28 t/d, melting point 118C. A film with a thickness of 30# was formed from this copolymer under the same conditions as in Example 1, and its properties were measured. The results are shown in Table 1.

Comparative example! Solid catalyst 1A1100# synthesized in Example 1, triethylaluminum 10 mmots i-butane 25t
.

Dialen 1245mot was introduced into a 40t autoclave which had been dehydrated and degassed, and the temperature was raised to %65C. Hydrogen 9.
It was pressurized at a pressure of 8 kflah"-G, and ethylene was introduced to bring the total pressure to 14 kp/exm"-G. By replenishing ethylene, a pressure of 14 k17 m"G was maintained, and the stirring power increased from the middle of 0 polymerization, during which polymerization was carried out for 1 hour.

Smooth stirring became difficult, and the cooling effect of the jacket was weakened, causing disturbances in the internal temperature control of the reactor. Massive copolymer 1080 after polymerization? I got it. This copolymer had an MI of 8.5 and a density t' of 0.934.

Table 1 Examples 3 to B Polymerization was carried out in the same manner as in Example 1, except that the solid catalyst (A) IsO synthesized in Example 1 and 0.8 mmott of triisobutylaluminum were used, except that the conditions shown in Table 2 were used. % and obtained the results shown in the table.

Examples 9-10 Capacity 250 d with dropping funnel and water-cooled reflux condenser installed
Oxygen and moisture inside the flask are removed by nitrogen substitution, and under nitrogen atmosphere * A74. ssMg(C2HI)6
．． Heptane 50- containing 4@(n -CJI@) 150 mmo/ was charged and heated to saC. Next, heptane 50- containing 50 mmot of dichloromethylsilane was weighed into a dropping funnel and heated to 80 C. stirring at 30 min.
After stirring for 1 hour at this temperature, the resulting white solid was isolated and dried. After reacting 2t of this white solid with 40-titanium tetrachloride at 150C for 2 hours,
The solid was isolated, washed with heptane and dried. 110 μm of this solid catalyst and 7.1 m of triisobutylaluminum
Polymerization was carried out in the same manner as in Example 1 except that mot was used and the conditions shown in Table 2 were used, and the results shown in Table 1 were obtained.

Claims (1)

[Scope of Claims] At least 92 types selected from the following groups: ethylene, (a) α-olefins having 5 to 4 carbon atoms, and (b) α-olefins having 5 to 15 carbon atoms. In the first step: substantially no solvent Below, ethylene and (
a) Copolymerizing an α-olefin having 3 to 4 carbon atoms to produce a copolymer with a weight of 10 to 80% based on the total amount of the final copolymer. 2nd step: A method for producing a copolymer, which comprises copolymerizing ethylene and an α-olefin having 5 to 15 carbon atoms at 0 to 120° C. in the presence of a hydrocarbon solvent.