JPS6169815A - Method for producing propylene random copolymer - 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 [Industrial Field of Application] The present invention relates to a method for producing a crystalline propylene random copolymer with excellent randomness. More specifically, the present invention relates to a method for producing a random copolymer suitable for film use, which has easy heat-sealability, large bulk density, and excellent fluidity, with high catalytic efficiency and good operability.

[Conventional technology]

Crystalline propylene/ethylene random copolymers containing a small proportion of ethylene are widely used and processed into various films, hollow bodies, injection molded products, and the like. In particular, in the film field, it is widely used as a variety of packaging materials because it has better heat sealability than propylene homopolymer. However, the propylene/ethylene random copolymers that have been provided so far cannot necessarily be said to have sufficiently high impact strength, nor can they be said to have sufficient heat sealability. In order to improve this, when trying to increase the ethylene content and obtain a propylene/ethylene random copolymer with high impact strength, relatively low melting point, and excellent heat sealability, it tends to become sticky, which hinders the polymerization operation. Since it is difficult to obtain a product with poor commercial value, the amount of melon containing 5 mol%
There is no commercially available propylene/ethylene random copolymer that exceeds this.

[Problem that the invention seeks to solve]

As a result of various studies aimed at obtaining a random copolymer with rough and rough properties, the present inventors found that propylene/ethylene random copolymers that have the same ethylene content or the same melting point and have been used in practical use In comparison, a method has been found for producing a random copolymer having excellent physical properties such as transparency, heat sealability, and improved impact strength.

Therefore, an object of the present invention is to produce a propylene/α-olefin random copolymer that has excellent transparency, heat sealability, impact resistance, etc., and has less stickiness and fish eyes when formed into a film, with a high catalytic effect. Moreover, it provides a manufacturing method with good operability.

Another object of the present invention is to provide a method for producing a propylene/α-olefin random copolymer, in which it has been difficult to obtain a polymer powder with excellent fluidity, in which the powdery state of the copolymer is improved. It is in.

According to the method of the present invention, (Al: a solid titanium catalyst component whose essential components are an interaction product of a magnesium compound, a titanium compound, and an electron donor; [B+: an organoaluminum compound)] Propylene and other α-
When producing a crystalline propylene random copolymer by copolymerizing olefins, aluminum 1 in the CB+ component
per gram atom of gaseous oxygenated compounds under standard conditions.
Crystalline propylene thene that can provide a film with excellent transparency, heat sealability, impact resistance, etc., and less stickiness and fish eyes when supplied at a ratio of o o i to 0.5 g atoms. A dam copolymer can be produced with high catalytic efficiency and with good operability.

A solid titanium catalyst component (Al is a solid titanium catalyst component containing as an essential component an interaction product of a magnesium compound, a titanium compound, and an electron donor used in the copolymerization of the present invention) A method in which donors are reacted in any order, or a method in which the above raw materials are further reacted in any order using a reaction aid such as a halogenating agent and/or an organoaluminum compound, or products obtained by each of the above methods. This type of catalyst component, in the absence of an inert diluent, usually has a specific surface area of 3 m/g or more, for example 30 m/g.
m/g to 1000 m/g, and the halogen/T1 (atomic ratio) is, for example, 4 to ioo, preferably 6 to 70,
Mg/Ti (atomic ratio) is in the range of, for example, 2 to 100, preferably 4 to 70, electron donor/methane (molar ratio) is in the range of, for example, 0.2 to 10, preferably 0.4 to 6, and is usually commercially available. Compared to magnesium halide,
It is usually in a highly amorphous state.

Typical examples of the electron donor include esters, polymers, acid anhydrides, and alkoxy silicon compounds.

Many methods for producing the titanium catalyst component as described above are already known and can be used in the present invention.

The titanium catalyst component preferably has a narrow particle size distribution and is spherical, ellipsoidal, or similar in shape.

Organoaluminum compound catalyst component ω that can be used in the present invention
) can be exemplified by a compound having at least 11V, 1 Al-carbon bond in the molecule; for example, (
1) General formula % formula % (where R and R are carbon atoms, usually 1 to 15,
The hydrocarbon groups preferably contain 1 to 4 hydrocarbon groups and may be the same or different from each other. X is halogen, m is 0 <
m≦5.0≦n<3, p is 0≦p<3, q is O≦q
<3, and m + n + p + q = 3), (2) an organoaluminum compound represented by the general formula % (where Ml is Ll, Na, or Ni, and R1 is the same as above). Examples include complex alkylated products of Group 1 metals represented by the same formula (same) and aluminum.

As the organoaluminum compounds belonging to the above (υ),
Examples include: (General formula 1 formula %) (Here, R and R are the same as above. m is preferably 1.
The number is 5≦m≦6. ), General formula 1 formula % (Here, R is the same as above. X is halogen, m is preferably Q<m<5.), General formula 1 formula % (Here, R1 is the same as above. m is Preferably 2≦m×3
It is. ), general formula % formula %) (where R and R are the same as above. X is halogen, O<
m≦3.0≦n <3.0≦q<3, m + n
+a = 3).

Among the aluminum compounds falling under (1), more specifically, trialkyl aluminum such as triethyl aluminum and tributyl aluminum, trialkenyl aluminum such as triisoprenyl aluminum,
In addition to dialkylaluminum alkoxides such as diethylaluminum ethoxide, dibutylaluminum butoxide, alkylaluminum sesquialfoxides such as ethylaluminum sesquiethoxide, butylaluminum sesquibutoxide, and RAl(OR). , 52
．． Partially alkoxylated alkyl aluminum halides, such as diethylaluminum hydride, dibutyl aluminum chloride, diethylaluminum bromide, ethyl aluminum sesquichloride, butyl aluminum sesquichloride, ethyl aluminum sesquichloride, etc. Alkylaluminum sesquihalogenides like aluminum sesquipromide, partially halogenated alkyl aluminum such as alkyl aluminum halides like ethyl aluminum dichloride, propyl aluminum dichloride, butyl aluminum dipromide, etc., diethylaluminum hydride, dibutyl aluminum dialkyl aluminum hydride such as hydride, partially hydrogenated alkyl aluminum hydride such as ethyl aluminum dichloride, alkyl aluminum halide such as probyl aluminum dihydride, ethyl aluminum ethoxy chloride, butyl aluminum butoxy chloride,
Partially alkoxylated and halogenated alkylaluminium such as ethylaluminum ethoxypromide, etc. Compounds belonging to (2) above, and L I
A# (C2H5) 4, L IA 7? < (+7 [(
15) Examples include 4.

Further, as a compound similar to (1), an organic aluminum compound in which two or more aluminum atoms are bonded via an oxygen atom or a nitrogen atom may be used. Examples of such compounds include (02H5)2AJOAj? (02H5)2, (C4H
9) 2AlOAl(C4H9)2, etc. can be exemplified.

Among these, it is particularly preferable to use trialkylaluminum and the above-mentioned alkyl aluminum in which two or more aluminums are combined.

Alternatively, it is preferable to use a mixture of these trialkylaluminums and alkyl aluminum halides.

Examples of the electron donor catalyst component (C) used in the present invention include organic acid esters, inorganic acid esters, alkoxy silicon compounds, carboxylic acid anhydrides, sterically hindered amines, and complexes thereof (for example, Lewis acid esters such as aluminum chloride). Examples include complexes with acids). Preferred examples include tEJ-keyed tlAfm esters of aromatic carboxylic acids such as benzoic acid, toluic acid, anisic acid, etc.
Examples include alkoxy silicon compounds such as diphenyldimethoxysilane, methyltrimethoxysilane, and tetraethoxysilane, and harmful amines such as 2.2.6.6-titramethylpipericine.

Such solid titanium catalyst component CAI, organoaluminum compound catalyst component (B) and electron donor catalyst component (C
) Many highly active and highly stereoregular catalysts are already known, and any of them can be used in the present invention. As an example, for example,
2-151691, JP-A-53-21093, JP-A-55-135102-3, JP-A-56-811,
JP-A-57-63310-2, JP-A-58-6300
No. 6, JP-A-58-138705-12 and the like can be mentioned.

In the present invention, random copolymerization of propylene and other α-olefins is carried out using a catalyst formed from the above (A), (Bl and (0)).The above other α-olefins used in the polymerization Examples include ethylene, 1-butene,
1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene, etc. and α of 04 or more
-Olefins can be mentioned, and two or more types of these may be used. In order to obtain a random copolymer having particularly interesting physical properties such as heat sealability and impact resistance, ethylene is used as the α-olefin, or ethylene and an α-olefin having 4 to 8 carbon atoms are used together. It is better.

Prior to the random copolymerization, a prepolymerization treatment may be performed in which the catalyst is brought into contact with a small amount of propylene in order to improve the catalyst activity, bulk density, fluidity, and the like. An example of prepolymerization treatment is, for example, Japanese Patent Publication No. 57-452.
No. 44, and can be used in the present invention.

Random copolymerization of propylene and other α-olefins is
It can be carried out in the liquid or gas phase, in the presence or absence of an inert solvent. Although the selection of each catalyst component used in the polymerization can be changed appropriately, the solid titanium catalyst component (A) is converted into titanium atoms per 11 polymerization volumes, for example, about o, o
It is preferable to use the compound at a concentration of about 0.05 to about 0.5 mmol, preferably about 0.005 to about 0.5 mmol. The organoaluminum compound catalyst component (B) is Ad
/Ti (atomic ratio) is, for example, about 1 to about 2000, particularly about 1 to about 500, and the electron donor catalyst component (01 can be appropriately selected depending on the type, but the CB + component 1 Per mole, approximately o, o o
It is preferred to use a proportion of from about 50 moles to about 50 moles, particularly from about 0.005 to about 50 moles.

When carrying out liquid phase polymerization, propylene may be used as a liquid medium, or examples of inert solvents include propane, butane, pentane, hexane, heptane, octane, decane, kerosene, and the like.

In the random copolymerization of the present invention, it is preferable to carry out random copolymerization of propylene and a small amount of other α-olefin. For example, it is preferable to adjust the feed ratio of propylene and other a-olefins so that the propylene component content in the random copolymer is about 99 to about 90 mol%, particularly about 98 to about 92 mol%. . This supply ratio can be appropriately selected and changed depending on the polymerization conditions and the type of α-olefin.

In the random copolymerization of the present invention, the standard state (0
``C1Iatn) to add a gaseous oxygen-containing compound (0.0001 to 0.5 mol per 1 g of aluminum as Bl component,
It is preferably supplied to the copolymerization system in a proportion of 0.001 to 0.2 mol. The oxygen-containing compound includes oxygen, -
Examples include carbon oxide, carbon dioxide, -oxidation chamber, nitrogen dioxide, sulfur dioxide, and carbonyl sulfide.

Among these, the use of oxygen is most preferred. Two or more of these oxygen-containing compounds may be used in combination, or they may be diluted with an inert gas such as nitrogen or argon. If the amount of the oxygen-containing compound used exceeds the above range, the improvement effect will be small and the catalyst activity will be greatly reduced, so it must be avoided. Furthermore, when oxygen is used, it is necessary in actual operation to use it within a range that does not create an explosive mixture.

When such an oxygen-containing compound is supplied to the copolymerization system, it can be directly added to the random copolymer system, but it is preferable to mix it with the gaseous raw material beforehand and then supply it. For example, when performing gas phase copolymerization, it is preferable to introduce an oxygen-containing compound into a gaseous raw material supply pipe, mix it with the gaseous raw material, and then supply it to the polymerization system.

The polymerization temperature in random copolymerization is, for example, about 5
A range of 0 to about 100"C1, particularly about 60 to about 90"C is preferred.The polymerization pressure is, for example, atmospheric pressure to about 200197cm2a, preferably about 2
For example, the range is from about 100 kq firn G to about 100 kq firn G.

In random copolymerization, for the purpose of controlling the molecular weight,
Molecular weight modifiers such as hydrogen can be used. Copolymerization can be carried out batchwise or continuously, but it is advantageous industrially to carry it out continuously. Random copolymerization may also be carried out in two or more polymerization stages with different conditions, in which case the present invention may be employed in at least one of these polymerization stages. Further, prior to the random copolymerization of the present invention, a step of producing a propylene homopolymer may be provided, in which case the oxygen-containing compound is added to the copolymerization system in advance of the random copolymerization. It can also be supplied to

〔Effect of the invention〕

According to the present invention, it is possible to obtain a crystalline propylene random copolymer that has a low melting point and good heat-sealability even if the amount of α-olefin as a copolymerization component is small. Such copolymers also have excellent impact resistance and anti-blocking properties. The copolymer powder obtained by polymerization also has a high bulk density and good fluidity. In addition, there is little adhesion of polymers to each other or buildup of walls during polymerization, and long-term continuous operation is possible. After heating and reacting 37 ml (225 mmol) of decane at 150'C for 2 hours to form a homogeneous solution, 1.67 g (11.3 mmol) of 7-talic anhydride was added to this solution, and the mixture was further heated at 130°C for 1 hour. Stir and mix to dissolve the phthalic anhydride into the homogeneous solution. After the homogeneous solution thus obtained was cooled to room temperature, the entire amount was dropped over 1 hour into 200 ml (1.8 mol) of titanium tetrachloride maintained at -20°C. After charging, the temperature of this mixed solution was raised to 110 °C over 4 hours, and when it reached 110 °C, 18.8 mmol of diisobutyl phthalate was added, and the mixture was stirred at the same temperature for 2 hours. Hold. 2
After the completion of the reaction for an hour, the solid part was collected by heating and filtered, and this solid part was resuspended in 275 mjl' of T i (1! e4), and then heated and reacted again at 110"C for 2 hours. .

After the reaction, the solid part was collected again by heating at 110"C.
and decane at room temperature until no free titanium compound is detected in the washing solution. The titanium catalyst component (AJ) synthesized by the above production method is stored as a decane slurry, and a part of it is dried for the purpose of investigating the catalyst composition. The composition was 2.1% by weight of titanium, 58.0% by weight of chlorine, 18.0% by weight of magnesium, and 12.7% by weight of diisobutyl phthalate.The specific surface area was 210 m
It was 27g.

In addition, the titanium catalyst component (Al was a granular catalyst with an average particle size of 13/7 and a geometric standard deviation (σg) of particle size distribution of 1.2. [Prepolymerization] The above T1 catalyst component was converted into T1 atoms. 0.4 mmol, suspended in 200 ml of hexane. 4 mmol of triethylaluminum, diphenyldimethoxysilane 8
After adding 2.75 g of propylene over 1 hour while maintaining the temperature at 20"C, the supernatant was replaced with sufficiently fresh hexane to obtain a prepolymerized T1 catalyst component. Polymerization] 0.75 ff of hexane in an autoclave with an internal volume of 2 g
and fully substituted with propylene at room temperature.

0.75 mmol of triethylaluminum, 0.075 mmol of diphenyldimethoxysilane and the above T1
Q, 015 mg of the catalyst component is added to the atomic system in terms of T1 atoms. After adding 0.15 mmol of oxygen into the system, 100,100 N of hydrogen was added, and the system was immediately heated.
Propylene/ethylene mixed gas (91,9/
8.1 mol 1 mol) feed is started. Total pressure 2.5
1. Supply a mixed gas so as to maintain kg/Cm G.
The entire amount after 5 hours of polymerization is precipitated in a large amount of methanol to obtain a polymer.

The yield of polymer was 153.3 g. Also, M of the polymer
FR is 4.2 g/l 0 min, ethylene content is 5.2
mo1%, the melting point by DSO was 152° C., the hexane extraction residue was 94.8 wt%, and the amount of n-decane soluble portion was 6.5 wt%.

Comparative Example 1 Polymerization was carried out using the same catalyst component as in Example 1 without adding oxygen.

The yield of polymer was 202.7 g. Also, the MFR of the polymer is 4.7 g/IQ min, and the ethylene content is 4.5.
Mo1%, the melting point by DSO is 138'C1, the residual rate of boiling hexane extraction is 93.5wt%, the amount of n-decane soluble portion is 7.5wt%, and the addition of oxygen creates a crystalline random mixture with excellent randomness. It can be seen that the polymer production rate increases.

Examples 2 and 3 In the polymerization of Example 1, 0.15 mmOl of oxygen was added to 0.10 mmol of carbon dioxide, 0.15 mmol, ho of carbon dioxide, respectively.
Polymerization was carried out in the same manner except that L was used instead. The results are shown in Table 1.

Example 4 [Preparation of titanium catalyst component] 83+6 ml of Mutican solution containing 50 mmol of ethylbutylmagnesium and 23.1 mg (150 mmol) of 2-ethylhexyl alcohol were heated at 80°C for 2 hours to form a homogeneous solution. After adding 1.4 J of ethyl benzoate to the solution to make a sufficiently homogeneous solution,
This was added dropwise to 200 m# of titanium tetrachloride maintained at -20°C over 1 hour with stirring. After completion of the dropwise addition, the temperature of the vaginal mixture was raised to 90°C over 1.5 hours, at which time 1.8 m+g of ethyl benzoate was added, and the mixture was further kept under stirring at 90"C for 12 hours, after which the solid portion was collected by filtration. , this was resuspended in 200m# titanium tetrachloride and heated to 90"C.
After carrying out a heating reaction for 2 hours, a solid substance is collected by filtration, thoroughly washed and dried with purified hexane until no free titanium compound is detected in the washing solution, and a titanium catalyst component is obtained. The components are 2.8% by weight of titanium and 6% of chlorine in terms of atoms.
1% by weight, 20% by weight of magnesium and 15.8% by weight of ethyl benzoate, and the catalyst component (A) is in the form of granules with an average particle size of 15μ and a geometric standard deviation (σg) of the particle size distribution of 1.4. It was a catalyst. Specific surface area is 18f'1m/
It was g.

[Prepolymerization]

A flask is charged with 0.4 mmol of the T1 catalyst component described above in terms of T1 atoms and 20QJ of hexane. A further 0.4 mmol of triethylaluminum is added. 2.1 g of propylene was fed over 1 hour while maintaining the temperature at 20"C. The supernatant was thoroughly removed by decantation using hexane.

[Overlapping]

An autoclave with an internal volume of 21 is sufficiently replaced with propylene. Propylene/Butene-1 (500g.

Molar ratio 75/25) was added to the system, and 1 mmol of triethylaluminum and 0.3 molar toluate were added to the system.
IJ moles and the titanium catalyst component mentioned above are 0 in terms of atoms.
．． Add 0.002 mg into the atomic system. Oxygen 0.01 miIJ
3000 Nmj of hydrogen after adding mol to the system? introduced, 7
The temperature was raised to 0'C and stirred for 1 hour. The residual monomer was removed by evaporation to obtain a polymer. The maximum polymer yield was 59 g, the apparent specific gravity was 0.30 g, /ml, MP'l (was 2.6
tr, / 10 minutes, Q containing 1-butene is 8.1 mol%,
The melting point was 131° C., and the amount of decane soluble portion was 2.4 wt%.

Claims (1)

[Scope of Claims] (A) a solid titanium catalyst component whose essential components are an interaction product of a magnesium compound, a titanium compound, and an electron donor; (B) an organoaluminum compound catalyst component; and (C) an electron donor catalyst component. When producing a crystalline propylene random copolymer by copolymerizing propylene and other a-olefins in the presence of a catalyst formed from
0.000 gaseous oxygenated compounds per atom under standard conditions
A method characterized in that it is supplied to the copolymerization system in a proportion of 1 to 0.5 g atoms.