JPH0319850B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides an ethylene-α-olefin copolymer with excellent low-temperature impact resistance, rigidity, and transparency, and which does not have a cloudy or sticky surface when molded. Concerning how to manufacture well. Ethylene/α with excellent low-temperature impact resistance, rigidity, and transparency suitable as blow grade or sheet grade for food containers or film grade for food packaging.
-Many methods for producing olefin copolymers have already been proposed, including the methods disclosed in Japanese Patent Publications No. 11230/1983 and Japanese Patent Publication No. 4992/1973. However, these methods have insufficient low-temperature impact resistance and transparency, whereas the methods proposed in Japanese Patent Application Laid-Open No. 53-35788 or Japanese Patent Application No. 56-35198 have insufficient physical properties such as impact resistance. However, there is a problem in that the appearance of the molded product is poor.To solve this problem, the method proposed in Japanese Patent Application No. 17583 not only has an excellent balance of physical properties, but also has a good appearance of the molded product. Although this is an excellent method, there was a problem in recovering the hydrocarbon compounds used in the polymerization. An object of the present invention is to provide a method for producing an ethylene-α-olefin copolymer that is excellent in low-temperature impact resistance, rigidity, and transparency, and also provides a molded product with an excellent appearance when molded. Another object of the present invention is to provide the above-mentioned excellent ethylene-α
- It is an object of the present invention to provide a method for producing an olefin copolymer with good yield and in which the step of recovering a solvent is omitted or reduced. The method for producing an ethylene-α-olefin copolymer of the present invention involves using a catalyst consisting of titanium tetrachloride supported on magnesium chloride, an organoaluminum compound, and an organic compound containing a C-O bond or a C-N bond. When copolymerizing and α-olefin, titanium tetrachloride supported on magnesium chloride is copolymerized with at least a part of the organoaluminum compound used in the polymerization and an organic compound containing a C-O bond or a C-N bond. The catalyst mixture is suspended in a hydrocarbon compound containing aromatic hydrocarbons by volume % or more, and the catalyst mixture thus prepared is subjected to a copolymerization reaction of ethylene and α-olefin using α-olefin itself as a medium. do. The titanium tetrachloride catalyst supported on magnesium chloride used in the present invention is preferably one in which titanium tetrachloride is supported on a complex of magnesium chloride and an organic compound containing a C-O bond or a C-N bond. Ru. As specific manufacturing methods, many known manufacturing methods can be applied. For example, a method of co-pulverizing magnesium chloride and an organic compound containing a C-O or C-N bond and then contacting it with liquid titanium chloride, a method of co-pulverizing the above three components, or a method of co-pulverizing magnesium chloride (dissolved (e.g., alcohols, ethers, esters) with a suitable precipitant (e.g., silicon halide, titanium halide, aluminum halide, organoaluminium), or simultaneously with precipitation, containing a C-O or C-N bond. There is a method of treating with a compound and then treating with liquid titanium tetrachloride, or a method of decomposing an organic Mg compound to form magnesium chloride and performing the same treatment as above. Also, in the above method
It is also possible to coexist inert compounds such as SiO ₂ and Al ₂ O ₃ . C-O or C used in catalyst preparation and polymerization
Examples of compounds containing -N bonds include compounds commonly used as stereoregularity improvers, such as esters, ethers, orthoesters, amines, amides, phosphoric esters, and phosphorous esters. Examples of organoaluminum compounds include dialkylaluminum chlorides such as diethylaluminum chloride, dipropylaluminum chloride, dibutylaluminum chloride, or mixtures thereof, or triethylaluminum, tripropylaluminum, tributylaluminium,
Trialkylaluminum such as trihexylaluminum or a mixture thereof may be used alone or in combination. In the present invention, the above three components, that is, titanium tetrachloride supported on magnesium chloride, an organoaluminum compound, and an organic compound containing a C-O bond or a C-N bond, are mixed with 5% by volume or more of an aromatic hydrocarbon. The catalyst mixture thus prepared is subjected to a copolymerization reaction. Prior to the copolymerization reaction, the above catalyst mixture is used in a small amount, for example per gram of titanium tetrachloride catalyst.
It is also possible to polymerize from 0.1 to 50 g of α-olefin. There are various methods for suspending the above, and for example, a method of stirring the three components above in the aromatic hydrocarbon-containing hydrocarbon compound can be used. The stirring temperature is −70~
The temperature is 50°C, preferably 20 to 30°C, and the stirring treatment time is from several minutes to several tens of hours, preferably from 5 minutes to 20 hours. The upper limit of the aromatic hydrocarbon content in the hydrocarbon compound is not particularly specified, and may be 100%. Furthermore, if the content of aromatic hydrocarbons in the hydrocarbon compound is less than 5 vol.%, problems such as the surface of the molded product becoming whitish and sticky when the obtained polymer is molded arise. Hydrocarbon compounds (other than aromatic hydrocarbons) include aliphatic saturated hydrocarbons,
Examples include alicyclic hydrocarbons, and specifically, hydrocarbons having 3 to 10 carbon atoms such as propane, butane, pentane, hexane, heptane, and cyclohexane are used. The organoaluminum component in the catalyst mixture suspended in the aromatic hydrocarbon-containing hydrocarbon compound is at least a part of the organoaluminum compound used in the polymerization, and in what range is the organoaluminum component suspended in the aromatic hydrocarbon-containing hydrocarbon compound? There is no particular restriction on whether it is a percentage or not. It is preferable to use the compound in an amount of 1 mole or more of the compound containing a C--O or C--N bond used in combination. Preferable examples of the aromatic hydrocarbon compound include aromatic hydrocarbon compounds having 6 to 12 carbon atoms, such as benzene, toluene, xylene, ethylbenzene, and cumene. Polymerization conditions include room temperature to 90℃, normal pressure to 50Kg/
Conventional polymerization conditions of cm ² -gauge can be employed, preferably 50-80°C. Furthermore, it is of course possible to obtain an ester/α-olefin copolymer with a desired molecular weight by adding a chain transfer agent such as hydrogen. In the present invention, it is more preferable to wash the slurry obtained in the above operation in countercurrent. Usually, after deactivating the catalyst and solubilizing the catalyst residue as necessary, the slurry is washed in countercurrent. Have it washed. The α-olefin used in countercurrent cleaning is the α-olefin mentioned above.
-Olefins, which may contain small amounts of ethylene, propane, butane, hexane, heptane, etc. The countercurrent washing tower is of the usual type, with a slurry inlet and a washing liquid outlet in the upper part, and a washing liquid inlet and a washed slurry outlet in the lower part, and is not particularly limited. By using the method of the present invention, an ester/propylene copolymer having excellent properties can be efficiently produced and is of industrial value. The present invention will be specifically explained below with reference to Examples. In the examples and comparative examples, the physical properties were determined by adding a phenolic stabilizer to the copolymer.
20/10000 weight ratio, calcium stearate
Add a lubricant at a weight ratio of 10/10,000 and a lubricant at a weight ratio of 20/10,000, granulate at 250℃, and then granulate at 240℃ to a thickness of 30μ and a width.
A 25 cm T-die film was made and evaluated. Measurements of each physical property are as follows. Intrinsic viscosity: Measured with tetralin solution at 135°C Haze (%): ASTM-1003-53 Blocking (%): After stacking two films and placing a 2 kg weight on them and keeping them at 50°C for 24 hours, as a percentage of the adhesion area calculation. Young's modulus (Kg/mm): Measured using an Instron using a 20mm x 220mm film. Tensile strength (Kg/ ^cm2 ): ASTM D882-64T. Impact (Kg・cm/mm): Film 10mm at 5℃
Calculated from the impact energy when a 10 mm object is damaged by impact with a spherical weight. Embossment: Determined visually after holding the film at 50°C for 24 hours. Example 1 A. Production of solid catalyst: A vibratory mill equipped with four crushing pots each having an internal volume of 4 and containing 9 kg of steel balls each having a diameter of 12 mm was prepared. 300 g of magnesium chloride in each pot under nitrogen atmosphere.
60 ml of tetraethoxysilane and 45 ml of α.α.α-trichlorotoluene were added and pulverized for 40 hours. Add 3 kg of the above-mentioned pulverized material and 20 kg of titanium tetrachloride to a fully dried autoclave with a nitrogen atmosphere and heat at 80°C for 120 min.
Stir for 1 minute, let stand, remove supernatant, add 35% of n-heptane, stir at 80°C for 15 minutes, let stand, remove supernatant, repeat washing 7 times, and then add n-heptane.
20 ml of heptane was added to form a catalyst slurry. When a portion of the slurry was sampled, n-heptane was evaporated, and analyzed, it was found that the catalyst contained 1.97 wt.% Ti. Also, the slurry concentration is 77g-catalyst/
-It was heptane. B. Polymerization reaction: 25 kg of propylene is charged into a jacketed autoclave equipped with a jacket, which has been thoroughly dried, purged with nitrogen, and further purged with propylene. On the other hand, put 500 ml of toluene, 2.6 ml of diethylaluminum chloride, 1.4 ml of methyl P-toluate, and 1 g of the above catalyst (including 13 ml of n-heptane) into flask 1, and heat the mixture at room temperature.
After stirring for an hour, 0.5 ml of triethylaluminum was added and the mixture was pressurized into the autoclave No. 100 mentioned above. A predetermined amount of hydrogen and ethylene was charged, then hot water was passed through the jacket to maintain the internal temperature at 70°C, and the gas phase hydrogen concentration was 6% and the gas phase concentration of ethylene was 2.4.
Polymerization was continued while charging hydrogen and ethylene to maintain the same percentage. Meanwhile, add 56.5 ml of n-heptane
While continuously pressurizing 3.5 ml of triethylaluminum dissolved at 0.5 ml/min and propylene into the autoclave at a rate of 125 g/min,
Polymerization was continued for hours. After 2 hours, add 10ml of diethylene glycol monoisopropyl ether.70
The slurry was stirred for 30 minutes at
h. From the bottom, pour a cleaning solution with a composition of 90% propylene, 5% propane, 1% ethylene, and 4% n-heptane.
Introduce the cleaning solution at a rate of 40 kg/h, and apply the cleaning liquid from above at 44 kg/h.
Kg/h, slurry washed from the bottom 26Kg/h
The slurry was taken out through a double pipe with an inner diameter of 3/4 inch and a length of 60 m, and was discharged into a cyclone maintained at atmospheric pressure. Double pipe is 1Kg/cm ²
- It was heated through G steam. The powder taken out from the cyclone contained 0.2% volatile matter. The obtained powder was further heated at 50℃ and 50℃.
After drying at mmHg for 10 minutes, 15.5 kg of polymer was obtained from the washing liquid from the top of the unidirectional flow washing tower.
0.7Kg of polymer was recovered. The ratio of the product to the total polymer (hereinafter referred to as product yield) was 95.7wt.%. The obtained powder was granulated and film-formed under the conditions described above, and its physical properties were measured. Examples 2 to 5 and Comparative Examples 1 to 2 500 ml of toluene for catalyst preparation and 500 ml of xylene
(Example 2), ethylbenzene 500ml (Example 3),
500 ml of cumene (Example 4), 500 ml of benzene (Example 5), 500 ml of n-hexane (Comparative example 1), 500 ml of n-heptane containing 1% toluene (Comparative example 2)
The results of polymerization carried out in the same manner as in Example 1 are shown in the table except that: 【table】

[Brief explanation of the drawing]

FIG. 1 is a flow chart of an embodiment of the present invention.

Claims (1)

[Claims] 1. Titanium tetrachloride supported on magnesium chloride,
Organoaluminium compounds and C-O bonds or C-
When copolymerizing ethylene and α-olefin using a catalyst made of an organic compound containing an N bond, titanium tetrachloride supported on magnesium chloride is copolymerized with at least a portion of the organoaluminum compound used in the polymerization and C-O together with an organic compound containing bonds or C--N bonds in a hydrocarbon compound containing not less than 5% by volume of aromatic hydrocarbons, and the catalyst mixture thus prepared was mixed with ethylene in the α-olefin itself as a medium. A method for producing an ethylene-α-olefin copolymer, which comprises subjecting it to a copolymerization reaction with α-olefin. 2 After copolymerization, the resulting copolymer slurry was
A method according to claim 1, in which countercurrent cleaning is performed with olefin.