JP2698085B2 - Method for producing styrenic polymer and its catalyst - Google Patents

Description

The present invention relates to a method for producing a styrenic polymer and a catalyst used in the method. More specifically, the stereochemical structure of the polymer chain mainly has a syndiotactic structure. The present invention relates to a method for efficiently producing a styrene-based polymer having the same and a catalyst used in the method.

[Problems to be solved by the prior art and the invention] Conventionally, as the styrene-based polymer, those having a stereochemical structure of an atactic structure and an isotactic structure are known, but a syndiotactic structure is known. No styrene polymer having a particularly high syndiotactic structure has been known.

Recently, the group of the present inventors has succeeded in developing a styrenic polymer having a stereochemical structure mainly having a syndiotactic structure, and disclosed one production method thereof in Japanese Patent Application Laid-Open No. 62-1877.
No. 08 discloses it. However, the catalyst used in this method is not only expensive but also has insufficient activity, and it is difficult to control the molecular weight, and there is a problem in producing a styrene-based polymer having a desired molecular weight. Furthermore, the use amount of the contact product between the expensive organoaluminum compound and the condensing agent is increased, and the production cost is increased, which is a serious obstacle in practical use.

In view of the above, the present inventors have conducted intensive research mainly in developing a styrene-based polymer having a syndiotactic structure, in order to develop an easy and efficient method of adjusting the molecular weight and a highly active catalyst suitable for the method. Stacked.

[Means for solving the problem]

As a result, by using a combination of a specific titanium compound and a specific two kinds of aluminum compounds as a catalyst, the activity, particularly the activity per expensive aluminoxane, is significantly improved, and the intended syndiotactic structure is obtained. Can efficiently produce a styrenic polymer having
In addition, they have found that the molecular weight can be easily adjusted. The present invention has been completed based on such findings.

That is, the present invention relates to (A) a compound represented by the general formula TiRXYZ, wherein R represents a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and X, Y and Z each independently represent a carbon atom of 1 to 12 carbon atoms. Alkyl group having 1 to 12 carbon atoms
An alkoxy group, an aryl group having 6 to 20 carbon atoms and 6 carbon atoms
Represents an aryloxy group having from 20 to 20, an arylalkyl group having from 6 to 20 carbon atoms, or halogen. (B) an organic aluminoxane having a high magnetic field component of 50% or less in a methyl proton signal region based on an aluminum-methyl group (Al-CH ₃ ) bond observed by a proton nuclear magnetic resonance absorption method and (B) C) A catalyst for producing a styrene-based polymer, comprising: an organoaluminum compound.

The catalyst of the present invention comprises the above components (A), (B) and (C) as main components, wherein the component (A) is
As described above, the general formula TiRXYZ (I) wherein R represents a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and X, Y and Z each independently represent a carbon atom of 1 Alkyl group of 1 to 12, carbon number of 1 to 12
An alkoxy group, an aryl group having 6 to 20 carbon atoms and 6 carbon atoms
Represents an aryloxy group having from 20 to 20, an arylalkyl group having from 6 to 20 carbon atoms, or halogen. ] It is a titanium compound represented by these. The substituted cyclopentadienyl group represented by R in the formula has, for example, 1 to 1 carbon atoms.
A cyclopentadienyl group substituted by one or more alkyl groups, specifically, a methylcyclopentadienyl group,
-Dimethylcyclopentadienyl group and pentamethylcyclopentadienyl group. X, Y and Z are each independently an alkyl group having 1 to 12 carbon atoms (specifically, a methyl group, an ethyl group, a propyl, a n-butyl group, an isobutyl group,
Amyl group, isoamyl group, octyl group, 2-ethylhexyl group, etc., alkoxy group having 1 to 12 carbon atoms (specifically, methoxy group, ethoxy group, propoxy group, butoxy group, amyloxy group, hexyloxy group, octyloxy) Group, 2
-Ethylhexyloxy group, etc.), an aryl group having 6 to 20 carbon atoms (specifically, phenyl group, naphthyl group, etc.), an aryloxy group having 6 to 20 carbon atoms (specifically, phenoxy group, etc.), 6 carbon atoms Represents an arylalkyl group (specifically, a benzyl group) or a halogen (specifically, chlorine, bromine, iodine or fluorine).

Specific examples of the titanium compound represented by the general formula (I) include cyclopentadienyltrimethyltitanium, cyclopentadienyltriethyltitanium, cyclopentadienyltripropyltitanium, cyclopentadienyltributyltitanium, pentamethyl Cyclopentadienyltrimethyltitanium, pentamethylcyclopentadienyltriethyltitanium, pentamethylcyclopentadienyltripropyltitanium, pentamethylcyclopentadienyltributyltitanium, cyclopentadienylmethyltitanium dichloride, cyclopentadienylethyltitanium dichloride Pentamethylcyclopentadienylmethyltitanium dichloride, pentamethylcyclopentadienylethyltitanium dichloride, cyclopentadienyldimethyltitanium monochloride Cyclopentadienyl diethyl titanium monochloride, cyclopentadienyl titanium trimethoxide, cyclopentadienyl titanium triethoxide, cyclopentadienyl titanium tripropoxide, pentamethylcyclopentadienyl titanium trimethoxide, pentamethylcyclo Pentadienyl titanium triethoxide, pentamethylcyclopentadienyl titanium tripropoxide, cyclopentadienyl monomethoxy titanium dichloride, cyclopentadienyl dimethoxy titanium monochloride, pentamethyl cyclopentadienyl monomethoxy titanium dichloride, cyclopenta Dienyl titanium triphenoxide, pentamethylcyclopentadienyl titanium triphenoxide, cyclopentadienyl diphenoxy titanium monochloride, pentamethy Cyclopentadienyl diphenoxy titanium monochloride, cyclopentadienyl monophenoxy titanium dichloride, pentamethylcyclopentadienyl monophenoxy titanium dichloride, cyclopentadienyl tribenzyl titanium, cyclopentadienyl methyl dibenzyl titanium, pentamethyl cyclo Examples include pentadienyltribenzyltitanium, pentamethyldiethoxymethyltitanium, indenyltitaniumtrimethoxide, indenyltitaniumtriethoxide, indenyltrimethyltitanium, indenyltribenzyltitanium and the like. Among them, a compound represented by the general formula TiRZ _{3 wherein} R represents a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and Z represents
A C12-C12 alkoxy group; a C6-C20 aryl group; a C6-C20 aryloxy group; and a C6-C20 arylalkyl group. ] The titanium compound represented by these is mentioned.

On the other hand, the component (B), which constitutes the main component of the catalyst together with the component (A), is obtained by contacting various organic aluminum compounds with a condensing agent. As the organoaluminum compound to react the raw material, usually formula AlR ¹ ₃ ···· (II) wherein, R ¹ represents an alkyl group having 1 to 8 carbon atoms. And specific examples thereof include trimethylaluminum, triethylaluminum, and triisobutylaluminum, among which trimethylaluminum is most preferred.

On the other hand, the condensing agent condensed with the organoaluminum compound is typically water, but any other condensing agent for alkylaluminum may be used.

Examples of the reaction product of an organoaluminum compound such as an alkylaluminum and water as a representative of the component (B) are specifically represented by the general formula: (Wherein n represents an integer of 2 to 50), or a linear alkylaluminoxane represented by the general formula: And a cyclic alkylaluminoxane having a repeating unit represented by the following formula (polymerization degree: 2 to 52).

In general, the contact product of an organoaluminum compound such as a trialkylaluminum and water is, together with the above-described chain alkylaluminoxane or cyclic alkylaluminoxane, an unreacted trialkylaluminum, a mixture of various condensation products, and furthermore, These are complexly associated molecules, which are various products depending on the contact conditions between the trialkylaluminum and water. Among them, in the present invention, the component (B) of the catalyst has a high magnetic field component of 50% or less in a methyl proton signal region based on an aluminum-methyl group (Al-CH ₃ ) bond observed by a proton nuclear magnetic resonance absorption method. belongs to. That is, when the above contact product is observed for its proton nuclear magnetic resonance ( ¹ H-NMR) spectrum in a toluene solvent at room temperature, the methyl proton signal based on Al—CH ₃ is found to be tetramethylsilane (TMS).
It is found in the range of 1.0 to -0.5 ppm by standard. Because TMS proton signals (0 ppm) is in the methyl protons observation area based on the Al-CH _3, methyl proton signal based on the Al-CH _3, measured relative to the methyl proton signal 2.35ppm toluene in TMS standard , High magnetic field components (ie, -0.1 to -0.5 ppm) and other magnetic field components (ie,
1.0 to -0.1 ppm), the component having the high magnetic field component of 50% or less, preferably 45 to 5% of the whole is used as the component (B) of the catalyst of the present invention.

The reaction between the organoaluminum compound and water at this time is not particularly limited, and may be performed according to a known method. For example, a method in which an organoaluminum compound is dissolved in an organic solvent and then brought into contact with water, a method in which an organoaluminum compound is initially added during polymerization and then water is added, and furthermore, a method in which a metal salt or the like is contained There is a method of reacting water of crystallization, water adsorbed on inorganic or organic substances with an organoaluminum compound, and the like.

As the component (C) constituting the catalyst of the present invention, various organoaluminum compounds can be used. Specifically, the general formula R ⁴ _k Al (OR ⁵ ) _m H _p X ¹ _q (IV) [Wherein, R ⁴ and R ⁵ each independently represent an alkyl group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, X ¹ represents halogen, k is 0 <k ≦ 3, and m is 0 ≦ m <3, p is 0 ≦ p
<3, q is 0 ≦ q <3, and k + m + p + q
= 3].

The following can be exemplified as the organoaluminum compound represented by the general formula (IV). p =
The one corresponding to the case where q = 0 is represented by the general formula R ⁴ _k Al (OR ⁵ )
_3-k (wherein R ⁴ and R ⁵ are the same as above, and k is preferably a number satisfying 1.5 ≦ k ≦ 3). m = p =
The equivalent to the case of 0 is represented by the general formula R ⁴ _k AlX ¹³ _-k (wherein
R ⁴ and X ¹ are the same as above, and k is preferably 0 <k <
3). The one corresponding to the case where m = q = 0 is represented by the general formula R ⁴ _k AlH _3-k (where R ⁴ is the same as above and k is preferably 2 ≦ k <3). .
The one corresponding to the case of p = 0 is represented by the general formula R ⁴ _k Al (OR ⁵ ) _m X
¹ _q (wherein R ⁴ , R ⁵ and X ¹ are the same as above, and 0 <k ≦
3, 0 ≦ m <3, 0 ≦ q <3, and k + m + q = 3).

In the organoaluminum compound represented by the general formula (IV), the compound in which p = q = 0 and k = 3 is selected from, for example, trialkylaluminums such as triethylaluminum and tributylaluminum or a combination thereof, and is preferable. Is triethylaluminum, tri-n-butylaluminum and triisobutylaluminum. When p = q = 0 and 1.5 ≦ k <3, a dialkylaluminum alkoxide such as diethylaluminum ethoxide or dibutylaluminum butoxide;
Ethylaluminum sesquichloride ethoxide, in addition to the alkyl sesquichloride alkoxides such as butyl sesquichloride butoxide, and the like R ⁴ _2.5 Al (OR ⁵⁾ partially alkoxylated alkyl aluminum having an average composition represented by _0.5 or the like it can. Examples of compounds corresponding to the case where m = p = 0 are dialkylaluminum halides (k = 2) such as diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide, etc., ethylaluminum sesquichloride, butylaluminum sesquichloride, Partial halogen such as alkylaluminum sesquihalogenide (k = 1.5) such as ethylaluminum sesquibromide, alkylaluminum dihalogenide (k = 1) such as ethylaluminum dichloride, propylaluminum dichloride, butylaluminum dibromide, etc. Alkyl aluminum. Examples of compounds corresponding to the case where m = q = 0 include dialkylaluminum hydrides (k = 2) such as diethylaluminum hydride and dibutylaluminum hydride, ethylaluminum dihydride,
Partially hydrogenated alkylaluminums such as alkylaluminum dihydrides (k = 1) such as propylaluminum dihydride. Examples of compounds corresponding to the case of p = 0 are alkylaluminated and halogenated alkylaluminums such as ethylaluminum ethoxycyclolide, butylaluminum butoxycyclolide, ethylaluminum ethoxybromide (k = m = q = 1). It is.

The catalyst of the present invention contains the above-mentioned components (A), (B) and (C) as main components. In addition to the above-mentioned components, other catalyst components can be further added if desired. The proportions of the components (A), (B) and (C) in this catalyst are as follows:
Although it depends on various conditions and cannot be uniquely determined,
Usually component (B) and (C) 1 to 10 as the ratio of the titanium aluminum in the component (A) in component, i.e. aluminum / titanium (molar ratio) ^4, preferably 10 to 10 ^3. As for the molar ratio of the component (B) and the component (C), (B) :( C) is 0.01: 1 to 1: 0.01, preferably 0.1: 1 to 1: 0.1, and more preferably. 0.5: 1 to 1: 0.5
It is.

The catalyst of the present invention as described above exhibits high activity mainly in producing a styrene-based polymer having a syndiotactic structure.

Therefore, the present invention further provides a method for producing a styrenic polymer using the above-mentioned catalyst.

In order to produce a styrenic polymer by the method of the present invention, styrene and / or a styrene derivative (alkylstyrene, alkoxyl) is used in the presence of a catalyst containing the above components (A), (B) and (C) as main components. Styrene monomers such as styrene, halogenated styrene and vinyl benzoate) are polymerized (or copolymerized), but this polymerization may be in bulk, and may be in the form of lumps, aliphatic hydrocarbons such as pentane, hexane and heptane, and oils such as cyclohexane. The reaction may be performed in a cyclic hydrocarbon or an aromatic hydrocarbon solvent such as benzene, toluene, and xylene. The polymerization temperature is not particularly limited, but is generally -30 to 120C, preferably -10 to 100C.

The styrenic polymer thus obtained mainly has a syndiotactic structure. Here, the predominantly syndiotactic structure in the styrenic polymer means a phenyl group or a substituted phenyl group whose stereochemical structure is mainly a syndiotactic structure, that is, a side chain with respect to a main chain formed from carbon-carbon bonds. Have alternate steric structures located in opposite directions, and their tacticity is determined by nuclear magnetic resonance ( ¹³⁾
C-NMR method). Tacticity measured by the ¹³ C-NMR method can be represented by the abundance ratio of a plurality of continuous structural units, for example, a dyad for two, a triad for three, and a pentad for five. However, in the present invention, "a styrenic polymer having mainly a syndiotactic structure" is usually 75% or more in dyad, preferably 85% or more, or 30% or more in pentad (racemic pentad), preferably Polystyrene with syndiotacticity of more than 50%,
Poly (alkyl styrene), poly (halogenated styrene), poly (alkoxy styrene), poly (vinyl benzoate) and a mixture thereof, or a copolymer containing these as a main component. Alkyl styrene), such as poly (methyl styrene),
Poly (ethylstyrene), poly (isopropylstyrene), poly (tert-butylstyrene), etc.
Examples of the poly (halogenated styrene) include poly (chlorostyrene), poly (bromostyrene), and poly (fluorostyrene). Also, poly (alkoxystyrene)
Examples thereof include poly (methoxystyrene) and poly (ethoxystyrene). Of these, particularly preferred styrene polymers include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), and poly (p-methylstyrene).
Examples include tertiary butyl styrene), poly (p-chlorostyrene), poly (m-chlorostyrene), poly (p-fluorostyrene), and a copolymer of styrene and p-methylstyrene.

Styrenic polymer produced by the method of the present invention,
Generally, the weight average molecular weight is 5,000 or more, preferably 10,000 to 2
0,000,000, number average molecular weight 2,500 or more, preferably 5,000
It has a high syndioctacycity as described above, but after polymerization, it is subjected to deashing treatment with a washing solution containing hydrochloric acid or the like, if necessary, and further washed, dried under reduced pressure, and then washed with methyl ethyl ketone or the like. If the soluble matter is removed by washing with a solvent and the resulting insoluble matter is further treated with chloroform or the like, a highly pure styrene-based polymer having extremely large syndiotacticity can be obtained.

In the method of the present invention, the amount of the component (C) used is adjusted, and the polymerization temperature is adjusted. By performing operations such as adjusting the amount of hydrogen gas introduced, the molecular weight of the resulting styrene polymer having a syndiooctic structure can be easily adjusted.

〔Example〕

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Made of glass having an inner volume of 500ml was prepared argon substitution of contact product of Example 1 (1) trimethylaluminum with water, copper sulfate pentahydrate _{(CuSO 4 · 5H 2 O)} 17.8g (71 mmol), toluene 200 ml and trimethylaluminum 24 ml (250 mmol) were added and reacted at 40 ° C. for 8 hours. Thereafter, toluene was further distilled off from the solution obtained by removing the solid portion under reduced pressure at room temperature to obtain 6.7 g of a contact product. Its molecular weight measured by freezing point depression method was 610. The high magnetic field component of the above according to the ¹ H-NMR measurement (i.e., -0.1
(-0.5 ppm) was 43%.

(2) Production of styrene-based polymer In a reaction vessel having an inner volume of 500 ml, 200 ml of heptane, 2 mmol of the contact product obtained in the above (1) as aluminum atom, 2 mmol of triisobutylaluminum, pentamethylcyclopentadiamine Add 0.08 mmol of enyltitanium trimethoxide and 50 ml of styrene, and add
The polymerization reaction was performed for an hour. After the completion of the reaction, the product was washed with a mixed solution of hydrochloric acid and methanol to decompose and remove the catalyst component, and dried to obtain 33.1 g of a polymer. Next, when this polymer was extracted with methyl ethyl ketone using a Soxhlet extractor, 98.0% of an extraction residue (MIP) was obtained. The weight average molecular weight of the obtained polymer was 850,000, and the number average molecular weight was 369,000. The polymer obtained by melting point and ¹³ C-NMR measurements was confirmed to be polystyrene having a syndiotactic structure.

Reference Example In Example 1 (2), except that 4 mmol of the contact product was used as an aluminum atom and no triisobutylaluminum was used.
By performing the same operation as in (2), polystyrene having a syndiotactic structure was produced.

Comparative Example 1 In Example 1 (2), except that titanium tetraethoxide was used as the titanium compound, 4 mmol of the contact product was used as the aluminum atom, and 4 mmol of triisobutylaluminum was used. By performing the same operation as in 1 (2), polystyrene having a syndiotactic structure was produced.

Comparative Example 2 In Example 1 (2), except that titanium tetraethoxide was used as the titanium compound, the contact product was used as 8 mmol as the aluminum atom, and no triisobutylaluminum was used.
The same operation as in Example 1 (2) was performed to produce polystyrene having a syndiotactic structure.

Example 2 A polystyrene having a syndiotactic structure was produced in the same manner as in Example 1 (2), except that 2 mmol of triethylaluminum was used instead of triisobutylaluminum. .

Example 3 The same operation as in Example 1 (2) was performed except that 2 mmol of monoethoxydiethylaluminum was used in place of triisobutylaluminum in Example 1 (2), and polystyrene having a syndiotactic structure was used. Manufactured.

Table 1 shows the catalyst compositions and polymerization results used in the above Examples 1 to 3, Reference Examples and Comparative Examples 1 and 2.

Examples 4 to 7 Example 1 (2) except that the conditions shown in Table 1 were used.
The same operation as described above was performed to produce a polystyrene having a syndiotactic structure. The results are shown in Table 1.

Example 8 (1) Preparation of contact product of trimethylaluminum and water In 200 ml of toluene solvent, 24.0 ml (0.250 mol) of trimethylaluminum and 23.7 g of copper sulfate pentahydrate (0.
[095] was reacted at 20 ° C for 24 hours, and the solid portion was removed to obtain a toluene solution containing 8.1 g of methylaluminoxane as a contact product. In this contact product, ¹ H-
The above-mentioned high magnetic field component by NMR measurement (that is, -0.1 to -0.5p
pm) was 48%.

(2) Production of styrene-based polymer The same operation as in Example 1 (2) was performed, except that the contact product obtained in (1) above was used, to produce polystyrene having a syndiotactic structure. The results are shown in Table 1.

[Effects of the Invention] As described above, the contact of the present invention has remarkably high activity. Therefore, when a styrene-based monomer is polymerized using this catalyst, a styrene-based polymer having high syndiotacticity can be efficiently produced. Moreover, according to the method of the present invention using this catalyst,
In producing the styrene-based polymer, the molecular weight can be easily adjusted.

The styrenic polymer having a syndiotactic structure thus obtained has excellent properties such as heat resistance and chemical resistance, and is widely and effectively used for various purposes.

Claims (3)

(57) [Claims] (A) A compound represented by the general formula: TiRXYZ, wherein R represents a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group, and X, Y and Z each independently represent a C 1-12 carbon atom. Alkyl group, carbon number 1-12
An alkoxy group, an aryl group having 6 to 20 carbon atoms and 6 carbon atoms
Represents an aryloxy group having from 20 to 20, an arylalkyl group having from 6 to 20 carbon atoms, or halogen. (B) an organic aluminoxane having a high magnetic field component of 50% or less in a methyl proton signal region based on an aluminum-methyl group (Al-CH ₃ ) bond observed by a proton nuclear magnetic resonance absorption method and (B) C) A catalyst for producing a styrenic polymer, comprising an organoaluminum compound. 2. The catalyst according to claim 1, wherein the organic aluminoxane is methylaluminoxane. 3. A method for producing a styrene polymer, comprising using the catalyst according to claim 1 in polymerizing styrene and / or a styrene derivative.