JPS58171409A - Ethylene copolymer and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a linear structure (i.e., substantially no long branched chains) and a
It concerns a special polymer of ethylene with a density of:

More specifically, the present invention relates to copolymers of ethylene and at least one α-olefin having a density of 0.9150 to 0.9450 g/cry, and also relates to methods for producing these polymers. .

A low-pressure polymerization process, in which ethylene is reacted with another alpha-olefin, preferably butene- 1 or copolymerized with octene-1) to give linear polyethylenes with low or medium densities (for example, German Patent Application No. 2,609,889, UK). Patent No. 1,131,528, U.S. Patent No. 4,067.88
2 and German Patent Application No. 2,014,172).

Such linear low-density copolymers not only have a linear structure rather than a branched chain structure, but also have significant differences in several properties such as modulus and elongation at break, as shown in the following table. It also differs from conventional low-density polyethylene (obtained by a radical-type high-pressure process) in that it has been improved.

Surface linear LDPE O, 92132, 027861714,
9 Conventional LDPK O,92302,021454510,
In Table 0, LDPE means low density polyethylene.

Linear low-density polyethylene has a greater mechanical resistance than conventional low-density polyethylene; this property allows for example raw material savings of 30% in operations to obtain films. Important advantages are also obtained in injection molding and filament and cable production due to improved mechanical properties at low temperatures, such as impact resistance. The properties of copolymers depend on the distribution of comonomers in the polymer chain.

The inventors disclosed Japanese Patent Application Publication Nos. 52-94,891 and 54-1.
No. 3.478, No. 56-120520, Patent Application No. 1983-
By using the known high-yield type catalyst systems for the production of high-density polyethylene and low-density polyethylene as disclosed in US Pat. It was discovered that it is possible to produce a combination, leading to the present invention.

The catalyst system used is essentially a component consisting of an organoaluminum compound and the reaction product of a metal vapor with a titanium compound and a halogen donor, or the product is modified by subsequent reaction with an organoaluminum compound or an alcohol. It includes ingredients that are made of

In the former case, the catalyst has the general formula % (where X is hydrogen, M is Mg, A11%
T.I.

(2), Mn, Cr, M□, Ca, and Zn, where n is the valence of M and m' is 1/n or more. This compound is prepared by a process consisting of vaporizing at least one of said metals in vacuo and reacting the metal vapor obtained with a titanium compound in the presence of a compound capable of releasing halogen atoms. This composition can be used as is, but it may be modified by reacting the composition with an organoaluminum compound. Yes M/ and M" are the same or different metals, selected from the above metal group,
Y, Y' and Y'' are the same or different halogens, and may be the same or different from X. always other than O, and n and p are each M'
and M", S is a number from 0 to 3, and R/ is preferably a hydrocarbon group having 10 or less carbon atoms. Alternatively, the catalyst can be expressed as Obtained by reacting a titanium compound selected from 10 genides and alcoholades, a vapor of a reducing electrically positive metal that is condensed at low temperatures, an organic-logen compound or an inorganic-logen compound, and an alcohol. It may also be a product.

For any of the catalysts, as a co-catalyst, an aluminum derivative having the general formula % (where Bi is a hydrocarbon group, X is ).logen and pl is a number from 1 to 3) is used. Always used.

In addition to the above composition, the catalyst system comprises (a) a titanium compound selected from chlorides and alcolades, magnesium vapor condensed at low temperature, an organic or inorganic compound;
The reaction product of a chloride compound and an alcohol, (bj general formula % formula % (wherein, X is Cg or 13r, and S is 0 to 2
It can also be obtained using aluminum trialkyls and aluminum halides corresponding to the number of aluminum halides as raw materials.

By using the above-mentioned catalyst composition, when the polymerization reaction of ethylene is carried out in the presence of at least one other α-olefin having 3 to 10 carbon atoms, low density polyethylene, which is described in more detail, can be used. For example, it has become possible to produce linear low-density polyethylene.

Alpha-olefins, especially butylene. In the case of -1. Use h
The effectiveness of the catalyst system was particularly remarkable.

Particular advantages are obtained by using 1-butene, 1-hexene and 1-octene.

That is, the final product, the crystalline copolymer, has a comonomer content of 1 mol% to 7 mol%, a melting point of 115°C to 130°C, and a crystallinity (X-ray) of 39% to 55%.
(depending on the amount of comonomer present) and melt flow index (according to the ASTM D-1238 method) from 0.1 to 509/10 min, and the density is always 0.
．． 945091cr! The following range is preferably o, 9tso to 0.9450 g/cril.

The distribution of comonomers in the polymer chain varies depending on the method used during production. This fact is evidenced by the different content of substances extracted by boiling hebutane, even if the density is the same and the melt flow index is the same.

The polymerization reaction is carried out both in suspension, in solution and in the gas phase, and if necessary, depending on the procedure adopted, linear or branched C4-C□0 hydrocarbons are used as reaction medium. , cyclic hydrocarbons, halogenated hydrocarbons or c44 min from said hydrocarbons.

Operations vary depending on the method adopted. The polymerization reaction in the gas phase consists of ethylene in various proportions depending on the desired product,
5 to 50 bar at a temperature selected from 10°C to 100°C, preferably 60°C to 90°C, in a mixture consisting of one α-olefin, preferably propylene or butene-1, and hydrogen as molecular weight regulator, This is preferably carried out by feeding the catalyst system under a pressure of 10 to 30 bar. The product thus obtained has a density of 0.9150 to 0.945
0 El/cd, characterized by a content of substances extracted by boiling hebutane (for products with the same melt flow index) of 65% to 5.9%.

Suspension polymerization is carried out with linear or branched aliphatic c4-C□.

It is carried out in a hydrocarbon solvent, preferably butane or isobutane, using a 03-c1G, preferably c3-c6 alpha-olefin comonomer and any of the above catalyst systems.

The polymerization reaction is carried out at a temperature selected from 20°C to 90°C, preferably 50°C to 80°C.
It is carried out under a pressure of bar, preferably 13 to 30 bar. The polymerization reaction can be carried out in a single step or in multiple steps, using reactors arranged in series and by feeding the gas phase at various compositions.

The product is recovered by evaporation of the solvent in the case of low-boiling solvents, or by centrifugation and drying of the powder, or by stripping.

Density obtained by single step method 0.9150 to 0.94
The 50 g/cd product has a fraction of 43% to 3% of the material extracted with boiling hebutane, while 2
The samples obtained with the process method have a fraction of the extracted material from 50% to 3.5%.

For polymerization methods in solution, the temperature of the polymerization reaction (1
It is necessary to operate with a solvent having a critical temperature higher than 30° C. (selected from the range 30° C. to 250° C.). Especially 1. Cyclic hydrocarbons such as cyclohexane and methylcyclohexane and boiling points of 120°C and 180°C
The use of normal- and -hydrocarbon mixtures at 1 °C has proven advantageous, since these have fairly good solvency power for the copolymers produced. Best results were obtained by maintaining the concentration of polymer in the reaction mixture not to exceed 40% by weight relative to solvent.

The molecular weight of the produced copolymer can be adjusted by the conventional method,
This is done by using hydrogen in an amount of 0.003 to 0.5 mole per mole of ethylene.

The polymerization reaction involves adding ethylene, hydrogen, an α-olefin (+03 to CIO, preferably C'6 to Cl01 linear or branched) and any of the above catalyst systems to the reaction environment for dissipating the heat of the polymerization reaction. This is done by introducing the reaction mixture with stirring in order to promote the reaction and improve the homogeneity of the system. The residence time of the polymerization solution is 1 minute or more depending on the polymerization reaction conditions. The duration is 4 hours, preferably 5 minutes to 4 hours, and the polymerization reaction pressure is relatively low, 5 to 100 bar.

The copolymer is recovered by removing unreacted monomer and solvent from the polymerization reaction mixture and inactivating the catalyst system with a suitable reagent.

The density thus obtained is 0.9150 to 0.9
The product with 45097 cd has a fraction of material extractable by boiling xylene of 56% to 5%.

In order to demonstrate the differences in the products obtained by the various operations, Table 1 lists the normal hepdan (n
-C7) are shown together with the mechanical properties of the correspondingly obtained films.

Aspects of operation will become clearer from consideration of the following examples. However, these Examples are merely for explaining the present invention and are not intended to limit the present invention.

Example 1 Preparation of Catalyst A rotary evaporator was used, with a tungsten filament placed in the center of the flask and connected to a power source. A cooling bath was placed horizontally below the flask.

The apparatus was connected to a vacuum source and nitrogen supply line via a three-way valve.

Wrap 1 g of magnesium wire around the tungsten reactor (suitably protected) and add 250 me of heptane, anhydrous and degassed, in a nitrogen atmosphere to the flask (SOOrd).
, 15 m (105 mmol) of 1-chlorohexane and 0.23 t+f (2.1 mmol) of TiC were charged. The flask was cooled to -70°C, then 10'
-2) After creating a vacuum, the tungsten coil was heated to vaporize the metal that had sprung on it. Once vaporization was complete, nitrogen was supplied to the apparatus and the flask was brought to room temperature while the mixture was stirred. Thereafter, the flask was heated to 80° C. for 1 hour (catalyst A).

After filling a flask (500 m ) with 70 g of polyethylene powder with controlled particle size and drying in vacuum for 30 minutes, the flask was filled with nitrogen and the previously obtained suspension was added to the flask, still in an inert atmosphere. Filled the flask. While stirring vigorously, heat the flask to 50°C to 60°C.
The solvent was removed in vacuo by heating to .

Once the evaporation of the solvent was complete, the flask was backfilled with nitrogen. The catalyst thus obtained (catalyst B) was a free-flowing powder of hazel color.

Analysis result: Ti 0.029 milligram atom/gMg
0,532 milligram atoms/gCe
1.12 Midens Gram Atom/9 Example 2 Autoclay 7 with Anchor Stirrer: (51) was degassed in vacuo, charged with 1.31 isobutane and the temperature raised to 60°C. Then, 1120 g of butene,
) Liisobutylaluminum 7mi'l'i 0.014
(equivalent to 5 milligram atoms) was added.

The temperature was maintained at 60° C. and ethylene was fed to keep the total pressure constant.

After the polymerization was carried out for 2 hours, 20 ml of ethanol was added to stop the reaction, and then the solvent was removed.

As a result, 310 g of polymer was obtained. This is Ti1
This corresponds to a yield of ~430 g of polymer per g. The properties of the obtained polymer were as follows.

Density 0.92109
/aA Butene content (NMR) 6.8
% (weight) CH11/100 C (number)
Melt-off index (MFI) at 1.702.16 degrees 1°2
,9710 minutes Melting point 12
2°C Crystallinity (X-ray) 42% Apparent density 0.33 9/cdl Average diameter of powder 350 microns Extract by boiling cdl 33.8% Example 3 The same equipment as Example 2 was used and the same However, the reaction was carried out using 8011 butenes.

This yielded polymer 26011. This is 360 k1 of polymer per 1g of titanium? This corresponds to a yield of The properties of the polymer are as follows.

Density 0.928411/cr/1 Butene content 4.8 wt% CHa
/ 100 C1,I MFI O, 4g/10 min Mikake qBBO230, 11/crl Melting point 124.5
°C Example 4 The reaction was carried out using the same equipment as in Example 2 and operating in the same manner, except that the amount of butene-1 was 1409. 350 g of polymer was obtained. This corresponds to a yield of 480 g of polymer per 1 g of Ti.

The polymer had the following properties.

Secret II O,915
217/cA butene ° content 10.
3 Weight%013/100C2,5 MFI (2,16yu) 1.2g71
0 minute apparent density 0.25 9/d Melting point 120 ℃
Heptane extract (at boiling) 52% Example 5 The same equipment as in Example 2 was used and the operations were performed as follows. That is, the reactor was charged with 1.31 isobutylene, and 6
After heating to 0°C, butene-140fI, triisobutylaluminum 6mH 1.70 bar (partial pressure),
Ethylene (partial pressure such that the total pressure is 114 bar) and the catalyst BO of Example 1. 5, 9 (Ti
O. (equivalent to 1145 milligram atoms) was added. The temperature was maintained at 60° C. and ethylene was introduced to keep the total pressure constant. After 15 minutes of polymerization reaction (which produced approximately 30% of the total polymer), 140 g of butene was charged and ethylene was fed again to bring the total pressure to 1.
The polymerization reaction was continued while maintaining a pressure of 4 bar.

After a total polymerization reaction time of 2 hours, the polymerization reaction was stopped with 19 cn of ethanol, and the solvent was distilled off. As a result, 320 g of polymer was obtained. This is 445 polymers per gram of Ti.
This corresponds to the yield of k17. The polymer had the following properties.

Density 0.9204
gi=minibutene 7.0 wt% melt flow index 1.1
Ji'/1 (1 apparent density o, a3
9/crA melting point 12
Extract by boiling C7 at 2°C 39
% Example 6 An autoclave (5/) equipped with an anchor stirrer was degassed under vacuum, and anhydrous and degassed hexane 2 was added to it.
1 and heated to 60°C.

Then 1130 g of butene, 6 methylene of triisobutylaluminum (partial pressure such that the a-gauge pressure is 6 bar) and the catalyst of Example 1 (B) 0.5 11 (Tt 0
．． (equivalent to 0.146 milligram atoms) was added.

The temperature was maintained at 60°C and ethylene was fed to keep the total pressure constant. After 2 hours of polymerization reaction, 1 ethanol
0cIIt f E. The autoclave was then cooled, the gas removed, and the polymer suspension stripped of solvent.

250 g of dry polymer was obtained (3 polymers per 1 g of Ti).
(equivalent to a yield of 50 kg). This polymer was a free-flowing powder and had the following properties:

Density 0.9213
9/crIt butene-1 content 6.2
Weight% Nord Flow Index
O-9 g/l 0 minute apparent density
Extract with boiling C7 0.23g/c11
50.1% Example 7 The apparatus of Example 2 was used and operated in the same manner, except that anhydrous normal-butane was used as the reaction solvent and the other polymerization reaction raw materials were used in the same amounts. , total gauge pressure 11
．． The reaction was carried out at 5 bar.

A quantity of 280 g of polymer was obtained (equivalent to a yield of 5° of 8 g of polymer per 1 g of Ti).This polymer had the following properties:

Density 0.9215 g
/cr! Butene content 6.5
Weight% CH3/100C 1.65
Melt flow index 0.909
710 minute crystallinity (according to X-ray method) 41
% Apparent Density 0.34 9/di Example 8 Using the same equipment and procedure as in Example 6, the reaction was carried out using anhydrous and degassed Hexene 3009. A polymer 240J was obtained having the following properties.

Density 0.9290
11/cr/ICH3/100C O
．． 90hexane content 5.4% by weight
Melt flow index 1.197
1o minute apparent density 0.25 91a&
Example 9 A test tube with a pre-dried and inert atmosphere tail was charged with catalyst (B) 2,9 and 36 milligram atoms of All-isoBu dissolved in 15-hexane. Stirring was performed with a magnetic stirrer, and after the snow, the hexane was distilled off with stirring until the sample was completely dry.

The catalyst 1 was placed under a nitrogen atmosphere in an autoclave (2e) equipped with a stirrer maintained in a dry and inert atmosphere.
g ('ri O.013 mi+)corresponding to a Durham atom) was filled. The autoclave was operated to exclude nitrogen, warmed to 70° C. and then a gas stream having the following composition was introduced at a pressure of 10 bar.

Composition Ethylene 80% (by volume) Butene
15% Hydrogen 5% Polymerization reaction 1
After an hour, 100 g of powdered polymer were obtained with the following properties:

Density 0.9198
9/crl butene-1 content 6.9
Weight% MF I 1.30
g/l 0 minute melting point 1
Extract by boiling C7 at 21.5°C 58
% Example 10 An autoclave (51) equipped with a stirrer was charged with anhydrous and degassed cyclobexane 2e containing 31 mmol of Ae (n-0C1), heated to a temperature of 150°C, and then octene-11009 , 0.5 bar (partial pressure) of hydrogen, ethylene (partial pressure such that the total gauge pressure is 10 bar) and 1.5 cn (corresponding to 0.012 milligram atoms of titanium) of the catalyst (A) of Example 1 were added. The pressure was kept constant for 30 minutes by feeding ethylene. Then the reaction was stopped, the autoclave was cooled and the gas was eliminated. The product thus obtained consisted of 140 g of polymer. This corresponds to a yield of 230 g of polymer per 1 g of titanium.

The properties of the obtained polymer are as follows.

dense [' o, 9zto g/c++
1 octene content 7.2% by weight
CH3/ 100 CO* 96

Claims (1)

[Claims] 1. Density 0.915 depending on the amount of comonomer present
0 to 0-945091cr! , melting point 115 to 130°C, crystallinity by Xg method 39 to 55%,
Melt flow index (ASTMD-1238)
A copolymer of ethylene and at least one other α-olefin, characterized in that it has a comonomer content of 0.1 to 50 g/10 min and a comonomer content of 1 to 7 molar. 2. Ethylene copolymer according to claim 1, wherein the other α-olefin is preferably selected from 1-butene, 1-hexene and 1-octene. 3. Density 0.915, depending on the amount of comonomer present
0 to 0.9450 (1/crit, melting point 115
to 130°C, crystallinity in X# method 39 to 5
5%, melt flow index (ASTMD-123
8) A process for the preparation of copolymers of ethylene and at least one other α-olefin having o,t to 50 g/10 min and a comonomer content of 1 to 7 molar,
Presence of a catalyst system consisting of a composition selected from 1) an organoaluminum compound and (2) a reaction product of a metal vapor with a titanium compound and a halogen donor, or a product obtained by modifying the product with an organoaluminum compound or an alcohol. A method for producing an ethylene copolymer, characterized in that: ethylene is contacted with at least one other alpha-olefin. 4. The catalyst has the general formula % (wherein, X is halogen, M is Mg, kl. Ti, V, Mn, Cr, Mo, Ca and z
4. The method according to claim 3, wherein the compound is a metal selected from n, n is the valence of M, and m' is 1/n or more. 5. The catalyst has the general formula TiX3.mM'Yn-qMI'Y/p-cAIY"8
-s R'; (wherein, X is a halogen, M' and M" are the same or different metals, and Mg, A7°Ti
, V, Mn1Cr, Mo, Ca and Zn, Y, Y' and Y" are the same or different halogens and may be the same or different from X, m and q are 0 It is also non-zero, but it is never O at the same time, C is not always O, n and p are the valences of Mj2 and M'', respectively, and S is O.
The method according to claim 3, wherein R' is a hydrocarbon group having 10 or less carbon atoms. 4. The method of claim 3, wherein said polymerization reaction is carried out by feeding a gas phase mixture comprising 6, ethylene, at least one other .alpha.,-onphine, and hydrogen. 7. Process according to any one of claims 3 to 6, in which the reaction is carried out at a temperature of 20° C. to 100° C. and a pressure of 5 to 50 bar. 8. The process according to claim 7, wherein the reaction is preferably carried out at a temperature of 60° C. to 90° C. and a pressure of 10 to 30 bar. 9. The method according to claim 3, wherein the polymerization reaction is carried out in a suspension. 10. The method according to claims 3 to 9, wherein the reaction is carried out in the presence of a solvent selected from among C4 to CIO aliphatic hydrocarbons and chlorogen-substituted hydrocarbons. 11. Process according to claim 9 or 10, in which the reaction is carried out at a temperature of 20° C. to 90° C. and a pressure of 1 to 60 bar. 12. The process according to claim 11, wherein the reaction is preferably carried out at a temperature of 50 DEG C. to 80 DEG C. and a pressure of 13 to 30 bar. 13. The method according to claim 3, wherein the polymerization reaction is carried out in a solution. ■, 4. The method according to claim 3, wherein the reaction is carried out at a temperature of 130°C to 250°C. 15. Claim 13 or 1 in which the reaction is carried out in the presence of a solvent having a critical temperature higher than the polymerization reaction temperature.
The method described in Section 4. 16. The method according to any one of claims 13 to 15, wherein the solvent is selected from cyclic hydrocarbons and hydrocarbon mixtures.