JPH04318006A - Production of propylene-styrene copolymer - Google Patents

Abstract

PURPOSE:To obtain in high yield and in high productivity the title copolymer with high heat resistance and rigidity, high in styrene content and catalytic activity by bulk polymerization between propylene and styrene in the presence of a specific catalyst. CONSTITUTION:The objective copolymer can be obtained by bulk polymerization between propylene and styrene in the propylene itself as medium pref. at 40-100 deg.C for 30min to 3hr under a pressure of 5-50kg/cm<2> in the presence of a catalyst made up of (A) a solid component containing titanium, magnesium and a halogen, (B) an organometallic compound (pref. a trialkylaluminum) and (C) an electron-donating compound (pref. a silyl ether such as trimethylmethoxysilane). The component A can be prepared, e.g. by cogrinding TiCl4 and e.g. magnesium chloride. It is preferable that, prior to the above polymerization, the propylene have been put to prepolymerization at 0-60 deg.C through the slurry polymerization process.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for producing a propylene-styrene copolymer, and more specifically, the present invention relates to a method for producing a propylene-styrene copolymer, and more specifically, propylene and styrene are copolymerized by a bulk polymerization method using propylene itself as a medium, thereby achieving high productivity. The present invention also relates to a method for producing a propylene-styrene copolymer, which can produce a copolymer with a high yield and a high styrene content.

0002

BACKGROUND OF THE INVENTION Hitherto, propylene-styrene copolymers have been produced by a method using a so-called Ziegler-Natta catalyst such as titanium trichloride-triethylaluminum or vanadium tetrachloride-triethylaluminum. However, these methods had low catalytic activity and the resulting copolymers were non-uniform.

[0003]More recently, in order to solve the above problems, methods for producing propylene-styrene random copolymers using a solution polymerization method using a Kaminsky type catalyst or a slurry polymerization method using a solid catalyst have been reported. However, the former method has problems such as the resulting polymer having a low molecular weight and the need for a large amount of organic aluminum. Furthermore, in the latter case, it is not possible to obtain a copolymer with a high content of styrene-based monomer units, so it is insufficient in terms of heat resistance and mechanical strength. Although it is possible to obtain a copolymer with a high content of body units, there is a problem in that case in that the catalytic activity is greatly reduced. Furthermore, the latter method requires a large amount of solvent and has practical problems such as complicated operations.

[0004] Therefore, a method for synthesizing a copolymer with good productivity, high catalytic activity, and high styrene content has been desired.

[0005]

[Problems to be Solved by the Invention] As a result of intensive research in order to solve the above-mentioned drawbacks of the conventional method, the present inventors have discovered that propylene and styrene are bulk copolymerized in the presence of a specific catalyst.
Moreover, they discovered that a copolymer with high catalytic activity and a high content of styrene-based monomer units in the copolymer was obtained, and furthermore, the obtained copolymer had high heat resistance and rigidity. The present invention has now been completed.

Namely, (A) a solid component containing titanium, magnesium, and halogen (hereinafter referred to as component (A)), (B) an organometallic compound (hereinafter referred to as component (B)), and (C) an electron-donating component. Using a catalyst consisting of a compound (hereinafter referred to as component (C)), propylene and styrene are
This is a method for producing a propylene-styrene copolymer, which is characterized by carrying out bulk polymerization using propylene itself as a medium.

Component (A), a solid component containing titanium, magnesium and halogen, is a titanium halide,
In particular, known catalysts in which titanium tetrachloride is supported on various magnesium compounds can be employed without any restrictions. As a method for producing this catalyst, any known method may be employed without any restriction. For example, a method of co-milling titanium tetrachloride with a magnesium compound such as magnesium chloride, a method of co-milling a titanium halide and a magnesium compound in the presence of an electron donor such as an alcohol, ether, ester, ketone or aldehyde. , or titanium halide in solvent,
Examples include a method of bringing a magnesium compound into contact with an electron donor.

The organometallic compound as component (B), which is one component of the catalyst of the present invention, is an organic compound such as zinc or aluminum. Specifically, dialkylzincs such as dimethylzinc and diethylzinc; trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisopropylaluminium; dialkylaluminum halides such as diethylaluminium chloride, diisopropylaluminum chloride, and diethylaluminum bromide; methyl Aluminoxanes such as aluminoxane and ethyl aluminoxane are used.
Particularly, trialkyl aluminum is effectively used.

Furthermore, another component of the present invention (
The electron donating compound as component C) is an organic compound containing oxygen, nitrogen, phosphorus or sulfur. Specifically, amines, amides, ketones, nitriles, phosphines, phosphoramides, esters, thioethers, acid anhydrides, silyl ethers, etc.
In particular, silyl ethers are effectively used.

More specifically, trimethylmethoxysilane, triethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, methylphenyldimethoxysilane, diphenyldiethoxysilane, ethyltrimethoxysilane, methyltrimethoxysilane, phenyltrimethoxysilane,
Examples include methyltriethoxysilane, ethyltriethoxysilane, and phenyltriethoxysilane.

In the method of the present invention, propylene and styrene are copolymerized using a catalyst consisting of the components (A), (B) and (C) described above. In the method of the present invention, propylene and styrene may be copolymerized in the presence of the above catalyst without any particular pretreatment, but it is preferable to carry out prepolymerization of propylene or propylene and styrene prior to this polymerization. .

Prepolymerization is carried out using ethylene, propylene, 1-
One or more monomers selected from α-olefins such as butene, 1-pentene, and styrene are used, with propylene being particularly preferred. It is usually preferable to apply slurry polymerization to this prepolymerization, and a saturated hydrocarbon or aromatic hydrocarbon such as hexane, heptane, cyclohexane, benzene, toluene, etc. can be used as the solvent. In addition, the prepolymerization temperature is -20 to 100℃, especially 0
The temperature is preferably 60° C. to 60° C., and the prepolymerization time may be appropriately determined depending on the prepolymerization temperature and the amount of polymerization in the prepolymerization. The pressure in preliminary polymerization is not limited, but in the case of slurry polymerization, it is generally from atmospheric pressure to about 5 kg/cm2. The amount of prepolymerization varies depending on the type of monomer to be prepolymerized, the properties of the target propylene-styrene copolymer, etc., and cannot be unambiguously determined, but usually when prepolymerization is performed with propylene, 100-5
000g-PP/g-Ti is preferred, and industrially 10
0 to 2500 g-PP/g-Ti is suitable.

In the copolymerization of propylene and styrene of the present invention, a catalyst system consisting of a combination of a solid component (A), an organometallic compound (B), and an electron-donating compound (C) is used. In this presence, bulk polymerization of propylene and styrene takes place using propylene itself as a medium. The charging ratio of the raw materials propylene and styrene should be selected depending on the required characteristics of the propylene-styrene copolymer to be produced, but generally the charging weight ratio of styrene/propylene is 0.05 to 5, preferably is selected from the range of 0.1 to 1.

The amount of each component of the catalyst used in the above copolymerization reaction is sufficient to be a so-called catalytic amount, but the weight ratio of propylene/component (A) is 100 to 50,000, preferably 100 to 20,000. used in If the charged weight ratio of styrene/component (A) is 10,000 or more, the catalyst activity tends to decrease and the amount of styrene introduced tends to decrease as well.

Component (B) is one titanium atom in component (A).
1 to 1000 moles, preferably 10 to 50 moles
0 mole, component (C) is 0.01 to 100 mole, preferably 0.1 to 5 mole per mole of titanium atom in component (A).
It is used in a proportion of 0 mol. In addition, when prepolymerization is performed, the catalyst used in the prepolymerization may be used as is, or a new catalyst component may be added or replenished.

[0016] As for the reaction conditions for the above copolymerization, the temperature is generally 20 to 200°C, preferably 40 to 100°C, the pressure is about 5 to 50 kg/cm2, and the polymerization time is 10 minutes to 10 minutes.
The duration is selected from 10 hours, preferably 30 minutes to 3 hours. Furthermore, the molecular weight during copolymerization can be controlled by known means, such as hydrogen.

[0017] As a polymerization method, after charging a determined amount of propylene and styrene, polymerization is started, or after charging a determined amount of propylene and a part of styrene, and after starting polymerization, styrene is gradually added. Any polymerization method can be used, such as a method in which propylene is polymerized alone, and then propylene and styrene or only styrene are added and polymerized.

After the copolymerization reaction is completed, unreacted monomers are removed to obtain the desired propylene-styrene copolymer.

[0019]

[Effects] By the production method of the present invention, it is possible to obtain a propylene-styrene copolymer which has a high content of styrene-based monomer units and therefore has high rigidity, high heat resistance, etc. Moreover, the method of the present invention has a catalytic activity as high as that of the slurry polymerization method, so propylene-styrene copolymers can be obtained efficiently.Furthermore, since no solvent is required, the process can be simplified, making it suitable for industrial use. This is a method with high practical value.

[0020]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 [Preparation of solid component containing titanium, magnesium, and halogen] The method for preparing the solid component containing titanium, magnesium, and halogen was based on the method of Example 1 of JP-A-58-83006. I went. That is, anhydrous magnesium chloride 0.95 g (10 mmol), decane 10
ml, and 2-ethylhexyl alcohol 4.7ml
After heating and stirring (30 mmol) at 125°C for 2 hours, 0.55 g of phthalic anhydride (3.75 mmol) was added to this solution.
mol) was added thereto, and the mixture was further stirred and mixed at 125° C. for 1 hour to obtain a homogeneous solution. After cooling to room temperature, 120
40 ml of titanium tetrachloride (0.36 mmo
The entire amount was added dropwise into 1) over a period of 1 hour. After the dropwise addition, the temperature of this liquid mixture was raised to 110°C over 2 hours, and 0.54 ml (2.5 mmol) of dibutyl phthalate was added.
) and stirred for 2 hours. After the reaction, collect the solid part by hot filtration, and add 200 ml of TiCl to this solid part.
After resuspending at 4, the reaction was heated again at 110° C. for 2 hours. After the reaction was completed, the solid portion was collected again by hot filtration.
It was thoroughly washed with decane and hexane until no free titanium compound was detected in the washing solution.

The solid Ti catalyst component prepared by the above production method was stored as a heptane slurry. solid Ti
The composition of the catalyst components was 2.1% by weight titanium, 57% by weight chlorine, 18% by weight magnesium, and 21.9% by weight diisobutyl phthalate.

[Prepolymerization] In a 1-liter autoclave purged with nitrogen, 200 ml of purified heptane, 50 mmol of triethylaluminum, and 1 liter of diphenyldimethoxysilane were added.
0 mmol and 5 m of solid Ti catalyst component in terms of Ti atom
After charging mol, propylene was added to 1 g of solid Ti catalyst component.
The polymer was continuously introduced into the reactor for 1 hour in an amount of 3 g, and polymerized at 15° C. for 1 hour. After the reaction was completed, the solid component of the obtained slurry was washed six times with purified heptane to obtain titanium-containing polypropylene.

[Main polymerization] 150 g of propylene was introduced into a 2 liter stainless steel autoclave which had been purged with nitrogen.
Styrene 150g, triethylaluminum 10mmo
After introducing 1 mmol of diphenyldimethoxysilane and 400 ml of hydrogen, the internal temperature of the autoclave was set to 5.
After raising the temperature to 0°C and adding 0.04 mmol of the titanium-containing polypropylene prepared above as titanium atoms, 1
Time polymerization was performed. After the reaction was completed, unreacted propylene was purged, and the resulting reaction product was washed with methanol and tetrahydrofuran to obtain a white granular polymer.

The soluble components of this polymer were extracted and separated using boiling heptane for 6 hours. The results are shown in Table 1.

The styrene content in the copolymer is 13C-
It was determined by NMR and infrared absorption spectra, and almost identical values were obtained. Further, Table 2 shows the melting point and crystallization temperature of the obtained polymer, and the physical properties of a molded product hot-pressed after adding an antioxidant.

Example 2 A reaction was carried out in the same manner as in Example 1 except that the amount of styrene used was 50 g. Table 1 shows the results.
and shown in Table 2.

Example 3 In Example 1, organoaluminum was mixed with 9 mmol of triethylaluminum and 1 mol of diethylaluminum chloride.
The reaction was carried out in the same manner as in Example 1 except that the amount was changed to mmol. The results are shown in Tables 1 and 2.

Example 4 In Example 1, 2 mmol of triethylaluminum and 8 mmol of diethylaluminum chloride were used as organic aluminum.
The reaction was carried out in the same manner as in Example 1 except that the amount was changed to mmol. The results are shown in Tables 1 and 2.

Example 5 150 g of propylene and 10 m of triethyl aluminum were placed in a 2 liter stainless steel autoclave which had been purged with nitrogen.
After introducing 1 mmol of diphenyldimethoxysilane and hydrogen, 0.04 mmol of titanium-containing polypropylene prepared in Example 1 was added as a titanium atom, and the mixture was polymerized at 25° C. for 30 minutes. At this time, 16 g of propylene was polymerized. Thereafter, 150 g of styrene was charged, the temperature was raised to 50° C., and polymerization was carried out for 1 hour. After the reaction was completed, the same treatment as in Example 1 was carried out. The results are shown in Tables 1 and 2.

Example 6 In Example 1, 0.08 mmol of titanium-containing polypropylene and 2 mol of triethylaluminum were added as titanium atoms.
The reaction was carried out in the same manner as in Example 1, except that the amount of diphenyldimethoxysilane was 0 mmol and the amount of diphenyldimethoxysilane was 2 mmol. The results are shown in Tables 1 and 2.

Example 7 In Example 1, 0.004 mmol of titanium-containing polypropylene as a titanium atom, 1 mmol of triethylaluminum, and 0.1 mmol of diphenyldimethoxysilane were used.
The reaction was carried out in the same manner as in Example 1, except that 1 was used. The results are shown in Tables 1 and 2.

Example 8 Except for changing the amount of hydrogen to 200 ml in Example 1,
The reaction was carried out in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Comparative Example 1 In a 1-liter autoclave purged with nitrogen, 300 ml of purified heptane, 150 g of styrene, 10 mmol of triethylaluminum, and 1 mm of diphenyldimethoxysilane were added.
After adding 0.04 mmol of the titanium-containing polypropylene prepared in Example 1 as a titanium atom, the propylene was continuously introduced into the reactor for 1 hour so that the amount of propylene charged was 150 g, and polymerized at 50 ° C for 1 hour. . After the reaction is complete,
The solid components of the obtained slurry were washed with heptane and tetrahydrofuran. The results are shown in Tables 1 and 2.

Comparative Example 2 The reaction was carried out in the same manner as in Example 1 except that 300 ml of purified heptane was added. The results are shown in Tables 1 and 2.

Comparative Example 3 The reaction was carried out in the same manner as in Example 7 except that 300 ml of propane was added. The results are shown in Table 1 and Table 2.
It was shown to.

Comparative Example 4 A reaction was carried out in the same manner as in Example 8 except that 300 ml of heptane was added. The results are shown in Tables 1 and 2.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

Claims (1)

[Claims] Claim 1: Propylene and styrene are mixed using a catalyst consisting of (A) a solid component containing titanium, magnesium and a halogen, (B) an organometallic compound, and (C) an electron-donating compound, and propylene itself is used as a medium. A method for producing a propylene-styrene copolymer, comprising carrying out bulk polymerization.