JPH0819175B2 - Method for producing styrene polymer and catalyst thereof - Google Patents

Description

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

[Problems to be Solved by Prior Art and Invention]

Conventionally, as styrene-based polymers, those having stereotactic structures of atactic structure and isotactic structure are known, but those of syndiotactic structure, particularly styrene-based polymers of high syndiotactic structure are known. The union was unknown.

Recently, the group of the present inventors succeeded in developing a styrene-based polymer having a stereochemical structure mainly having a syndiotactic structure, and one of the production methods thereof was disclosed in JP-A-62-18770.
No. 8 publication. However, the catalyst used in this method is not only costly, but also has insufficient activity,
There were various problems in practical use. In particular, the amount of the contact product of the expensive organoaluminum compound and the condensing agent used increases, resulting in an increase in production cost, which is a serious obstacle to practical use.

Therefore, the inventors of the present invention have conducted extensive studies mainly to develop an efficient method for producing a styrene polymer having a syndiotactic structure and a highly active catalyst suitable for the method.

[Means for solving the problem]

As a result, in the catalyst comprising the titanium compound (A) and the contact product of (B) trimethylaluminum and water, or in the catalyst obtained by adding the organoaluminum compound (C) to the catalyst, the catalytic production of the component (B). It has been found that by using a substance having a specific molecular weight, the catalytic activity is remarkably improved, and the production efficiency of a target styrene polymer having a syndiotactic structure is dramatically increased. The present invention has been completed based on such findings.

That is, the present invention relates to a contact product of (A) a titanium compound and (B) an organoaluminum compound with water, which has a molecular weight of 1000 to 22 as measured by a benzene solution freezing point depression method.
A catalyst for producing a styrenic polymer (hereinafter referred to as catalyst I), which comprises a contact product of 00, and from the above components (A), (B) and (C) organoaluminum compound The present invention provides a catalyst for producing a styrenic polymer (hereinafter referred to as catalyst II) characterized by the following.

There are various titanium compounds as the component (A) in the catalysts I and II of the present invention. For example, the general formula TiR ¹ _a R ² _b R ³ _c X ¹ _{4- (a + b + c)} … (α) or TiR ¹ _d R ² _e X ¹ _{3- (d + e)} … (β) [in the formula , R ¹ , R ² and R ³ are hydrogen atom and carbon number 1 respectively
To C20 alkyl group, C1 to C20 alkoxy group, C6 to C20 aryl group, C6 to C20 alkylaryl group, C6 to C20 arylalkyl group, C6 to C6
A 20 aryloxy group, a C1-20 acyloxy group, a cyclopentadienyl group, a substituted cyclopentadienyl group or an indenyl group is shown, and X ¹ is a halogen atom. a, b, and c each represent an integer of 0 to 4, and d and e each represent an integer of 0 to 3. ] At least one compound selected from the group consisting of titanium compounds and titanium chelate compounds represented by:

R ¹ , R ² and R ^{3 in} this general formula (α) or (β)
Are a hydrogen atom and an alkyl group having 1 to 20 carbon atoms (specifically, methyl group, ethyl group, propyl group, n-butyl group,
Isobutyl group, amyl group, isoamyl group, isobutyl group, octyl group, 2-ethylhexyl group, etc.), carbon number 1
To 20 alkoxy groups (specifically, methoxy, ethoxy, propoxy, butoxy, amyloxy, hexyloxy, phenoxy, 2-ethylhexyloxy, etc.), C6-20 aryl, alkyl Aryl group, arylalkyl group (specifically, phenyl group, naphthyl group, tolyl group, xylyl group, benzyl group, etc.),
Aryloxy group having 6 to 20 carbon atoms (specifically, phenoxy group, etc.), Acyloxy group having 1 to 20 carbon atoms (specifically, heptadecylcarbonyloxy group, etc.), cyclopentadienyl group, substituted cyclopentadiene An enyl group (for example, a cyclopentadienyl group substituted with one or more alkyl groups having 1 to 6 carbon atoms, specifically, methylcyclopentadienyl group, 1,2-dimethylcyclopentadienyl group, pentamethylcyclo (Pentadienyl group, etc.) or indenyl group. These R ¹ , R ² and R ³ may be the same or different. X ¹ represents a halogen atom, that is, chlorine, bromine, iodine or fluorine. Furthermore, a, b, and c each represent an integer of 0 to 4, and d and e each represent an integer of 0 to 3.

Specific examples of the tetravalent titanium compound and titanium chelate compound represented by the general formula (α) include methyltitanium trichloride, titanium tetramethoxide, titanium tetraethoxide, monoisopropoxytitanium trichloride and diisopropoxy. Titanium dichloride, triisopropoxy titanium monochloride, tetra (2-ethylhexyloxy) titanium, cyclopentadienyl titanium trichloride, biscyclopentadienyl titanium dichloride, titanium tetrachloride, titanium tetrabromide, bis (2,4- Pentanedionate) titanium oxide, bis (2,4-pentanedionate) titanium dichloride, bis (2,4-pentanedionate) titanium dibutoxide, cyclopentadienyl trimethyl titanium, cyclopentadienyl triethyl titanium, cyclopenta Jie Rutripropyl titanium, cyclopentadienyl tributyl titanium, pentamethyl cyclopentadienyl trimethyl titanium, pentamethyl cyclopentadienyl triethyl titanium, pentamethyl cyclopentadienyl tripropyl titanium, pentamethyl cyclopentadienyl tributyl titanium, cyclopenta Dienylmethyl titanium dichloride, cyclopentadienyl ethyl titanium dichloride, pentamethyl cyclopentadienyl methyl titanium dichloride, pentamethyl cyclopentadienyl ethyl titanium dichloride, cyclopentadienyl dimethyl titanium monochloride, cyclopentadienyl diethyl titanium mono Chloride, cyclopentadienyl titanium trimethoxide, cyclopentadienyl titanium triethoxide, pentamethylcyclopenta Dienyl titanium trimethoxide, pentamethyl cyclopentadienyl titanium triethoxide, pentamethyl cyclopentadienyl titanium trichloride, cyclopentadienyl monomethoxy titanium dichloride, cyclopentadienyl dimethoxy titanium monochloride, pentamethyl cyclopenta Dienyl monomethoxy titanium dichloride, cyclopentadienyl titanium triphenoxide, cyclopentadienyl diphenoxy titanium monochloride, cyclopentadienyl monophenoxy titanium dichloride, cyclopentadienyl tribenzyl titanium, cyclopentadienyl dibenzylmethyl titanium , Pentamethylcyclopentadienyl tribenzyl titanium, pentamethyl titanium diethoxide, indenyl titanium trichloride, indenyl titanium trime Kishido, indenyl titanium triethoxide,
Examples thereof include indenyl trimethyl titanium and indenyl tribenzyl titanium.

As the titanium compound as the component (A), in addition to the above, a general formula [Wherein R ⁴ and R ⁵ are a halogen atom and a carbon number of 1 to 20
And an alkoxyl group and an acyloxy group, and k is 2 to 20. ] A condensed titanium compound represented by the following may be used.

Further, the titanium compound may be used in the form of a complex with an ester or ether. The trivalent titanium compound represented by the general formula (β), which is another type of the component (A), is typically titanium trihalide such as titanium trichloride, cyclopentadienyl such as cyclopentadienyl titanium dichloride. Examples thereof include titanium compounds, and those obtained by reducing tetravalent titanium compounds. These trivalent titanium compounds may be used in the form of a complex with an ester or ether.

Next, as the component (B) of the catalysts I and II of the present invention, a contact product of an organoaluminum compound and water is used.
The organoaluminum compound used as the reaction raw material is usually of the general formula AlR ⁶ ₃ (a) [In the formula, R ⁶ represents an alkyl group having 1 to 8 carbon atoms. ] Organoaluminum compounds represented by the following, specifically, trimethylaluminum, triethylaluminum, triisobutylaluminum and the like can be mentioned, among which trimethylaluminum is most preferable.

Examples of the reaction product of an organoaluminum compound such as alkylaluminum as a representative of the component (B) and water are specifically represented by the general formula (Wherein n represents the degree of polymerization) or a chain alkylaluminoxane represented by the general formula There is a cyclic alkylaluminoxane having a repeating unit represented by

In general, the contact product of an organoaluminum compound such as trialkylaluminum and water is water, along with the above-mentioned chain alkylaluminoxane and cyclic alkylaluminoxane, unreacted trialkylaluminum, a mixture of various condensation products, and further these. Molecules are intricately associated with each other, and they are various products depending on the contact conditions of trialkylaluminum and water. Among them, in the present invention, the contact product of an organoaluminum compound such as the above-mentioned trialkylaluminum (preferably trimethylaluminum) and water, which is preferably used as the component (B) of the catalyst, has an average molecular weight of that of the benzene solution. 1000-3000 as the molecular weight measured by freezing point depression method, preferably 1050
It ranges from ~ 2200.

The reaction between the organoaluminum compound and water at this time is not particularly limited, and the reaction may be performed according to a known method. For example, a method in which an organoaluminum compound is dissolved in an organic solvent and brought into contact with water, a method in which an organoaluminum compound is initially added at the time of polymerization and then water is added, and further, a metal salt is contained. There is a method of reacting water of crystallization, water adsorbed on an inorganic substance or an organic substance with an organoaluminum compound. Although this reaction proceeds in the absence of a solvent, it is preferably carried out in a solvent, and preferable solvents include aliphatic hydrocarbons such as hexane, heptane, and decane, or aromatic hydrocarbons such as benzene, toluene, and xylene. Can be raised.

In the reaction of the above-mentioned organoaluminum compound with water, if the reaction temperature is set to be slightly higher and the reaction time is set to be longer, the molecular weight is increased and a contact product having a desired molecular weight range is obtained.

The catalyst I of the present invention comprises the above-mentioned components (A) and (B), and the catalyst II is constituted by blending the component (C) together with the components (A) and (B). Constituting this catalyst II (C)
As the component, various organoaluminum compounds can be used, but specifically, the general formula R ⁷ _k Al (OR ⁸ ) _m H _p X ² _q ... [In the formula, R ⁷ and R ⁸ each independently have a carbon number. 1 to 8, preferably an alkyl group having 1 to 4 carbon atoms, X ² represents halogen, k is 0 <k ≦ 3, m is 0 ≦ m <3, and p is 0 ≦ p.
<3, q is 0 ≦ q <3, and k + m + p + q
= 3].

Examples of the organoaluminum compound represented by the above general formula include the following. p = q =
The case of 0 corresponds to the general formula R ⁷ _k Al (OR ⁸ ) _3-k (wherein R ⁷ and R ⁸ are the same as defined above, and k is preferably 1.5
≦ k ≦ 3). The case where m = p = 0 corresponds to the general formula R ⁷ _k AlX ² _3-k (wherein R ⁷ and X ¹
Is the same as above and k is preferably 0 <k <3). The case corresponding to m = q = 0 is represented by the general formula R ⁷ _k AlH _3-k (wherein R ⁷ is the same as above,
k is preferably 2 ≦ k <3). p =
The case corresponding to 0 corresponds to the general formula R ⁷ _k Al (OR ⁸ ) _m X ² _q (wherein R ⁷ , R ⁸ and X ² are the same as described above, and 0 <k ≦ 3,0
≦ m <3, 0 ≦ q <3, and k + m + q = 3).

In the organoaluminum compound represented by the above general formula, the compound of p = q = 0 and k = 3 is selected from trialkylaluminums such as triethylaluminum, tributylaluminum and the like, or a combination thereof, and preferred is triethylaluminum. , Tri-
n-butylaluminum and triisobutylaluminum. In the case of p = q = 0 and 1.5 ≦ k <3, in addition to dialkylaluminum alkoxides such as diethylaluminum ethoxide and dibutylaluminum butoxide, and alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide, Partially alkoxylated alkylaluminum having an average composition represented by R ⁷ _2.5 Al (OR ⁸ ) _{0.5 and the} like can be mentioned. An example of the compound corresponding to the case of m = p = 0 is diethylaluminum chloride,
Dialkylaluminum halogenide (k = 2) such as dibutylaluminum chloride, diethylaluminum bromide, etc., alkylaluminum sesquihalogenide (k = 1.5), ethyl such as ethylaluminum sesquichloride, butylaluminum sesquibromide, ethylaluminum sesquibromide, ethyl Aluminum dichloride,
Partially halogenated alkyl aluminum such as alkyl aluminum dihalogenide (k = 1) such as propyl aluminum dichloride, butyl aluminum dibromide and the like. Examples of compounds corresponding to the case of m = q = 0 are dialkyl aluminum hydrides (k = 2) such as diethyl aluminum hydride and dibutyl aluminum hydride, and alkyl aluminum dihydrides (k) such as ethyl aluminum dihydride and propyl aluminum dihydride. = 1) and other partially hydrogenated alkylaluminums. Examples of compounds corresponding to the case of p = 0 are partially aluminumized and halogenated alkyl aluminums such as ethyl aluminum ethoxy chloride, butyl aluminum butoxycyclolide, ethyl aluminum ethoxy bromide (k = m = q = 1). Is.

The catalyst I of the present invention contains the above components (A) and (B) as main components, and the catalyst II contains the components (A), (B) and (C) as main components. In addition to the above, other catalyst components can be added if desired. The blending ratios of the components (A), (B) and (C) in these catalysts differ depending on various conditions and are not uniquely determined, but usually the components (B) and (B) are usually used. The ratio of aluminum (aluminum in component (B) in the case of catalyst I) to titanium in component (A), that is, aluminum / titanium (molar ratio) is 1 to 10 ⁴ , preferably 10 to 10 ³
Is.

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

Therefore, the present invention further provides a method for producing a styrenic polymer using the catalyst I or II as described above.

To produce a styrenic polymer by the method of the present invention, a catalyst I containing the above-mentioned components (A) and (B) as a main component is used.
Alternatively, styrene such as styrene and / or styrene derivative (alkyl styrene, alkoxy styrene, halogenated styrene, vinyl benzoate, etc.) in the presence of the catalyst II containing the components (A), (B) and (C) as a main component. The system monomers are polymerized (or copolymerized), but this polymerization may be in a bulk form, and aliphatic hydrocarbons such as pentane, hexane and heptane, alicyclic hydrocarbons such as cyclohexane and aromatic carbonization such as benzene, toluene and xylene. You may perform in a hydrogen solvent. The polymerization temperature is not particularly limited, but is generally -30 to 120 ° C, preferably -10 to 100 ° C.

The styrene-based polymer thus obtained mainly has a syndiotactic structure. Here, the predominant syndiotactic structure in the styrene-based polymer means that the stereochemical structure is predominantly a syndiotactic structure, that is, a phenyl group or a substituted phenyl group which is a side chain with respect to the main chain formed from carbon-carbon bonds. Have alternating three-dimensional structures, and their tacticity is based on the isotopic carbon nuclear magnetic resonance method ( ¹³
C-NMR method). Tacticity measured by the ¹³ C-NMR method can be indicated by the abundance ratios of a plurality of continuous constitutional units, for example, two diads, three triads, and five pentads. However, the "predominantly styrenic polymer having a syndiotactic structure" referred to in the present invention is usually 75% or more, preferably 85% or more with a diad, or 30% or more with a pentad (racemic pentad), preferably Polystyrene having a syndiotacticity of 50% or more,
It means poly (alkyl styrene), poly (halogenated styrene), poly (alkoxy styrene), poly (vinyl benzoic acid ester) and mixtures thereof, or copolymers containing these as the main components. As alkyl styrene), poly (methyl styrene),
There are poly (ethyl styrene), poly (isopropyl styrene), poly (tertiary butyl styrene), etc.,
Examples of 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 preferable styrene-based copolymers include polystyrene, poly (p-methylstyrene), poly (m-methylstyrene), and poly (p-methylstyrene).
-Tert-butyl styrene), poly (p-chlorostyrene), poly (m-chlorostyrene), poly (p-fluorostyrene), and further a copolymer of styrene and p-methylstyrene.

The 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
Although it has a high syndioctacity as described above, it is subjected to deashing with a washing liquid containing hydrochloric acid or the like as necessary after polymerization, and further washed and dried under reduced pressure to remove 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 high-purity styrene-based polymer having extremely high syndiotacticity can be obtained.

〔Example〕

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

Example 1 (1) Contact product of aluminum compound and water ((B)
Preparation of component) In a glass container having an inner volume of 500 ml and having been replaced with argon, 200 ml of toluene, 23.7 g (95 mmol) of copper sulfate pentahydrate (CuSO ₄ .5H ₂ O) and 24 ml (250 mmol) of trimethylaluminum were placed, and 40 The reaction was carried out at 30 ° C for 30 hours. Then, from the solution obtained by removing the solid portion, volatile components were further distilled off under reduced pressure to obtain 7.04 g of a contact product. The molecular weight of this product measured with the freezing point depression method in a benzene solution was 1100.

(2) Production of styrene polymer In a reaction vessel having an internal volume of 500 ml, 50 ml of toluene, the above (1)
The catalytic product obtained in Step 1 was used as an aluminum atom in an amount of 10 mmol, tetraethoxy titanium 0.1 mmol and styrene 2
00 ml was added and the polymerization reaction was carried out at 50 ° C. for 1 hour. After completion of the reaction, the product was washed with a hydrochloric acid-methanol mixed solution to decompose and remove the catalyst component, and dried to obtain 32.7 g of a polymer. Next, this polymer was extracted with methyl ethyl ketone using a Soxhlet extractor to obtain an extraction residue (polymer). The weight-average molecular weight of the polymer as the extraction residue was 600,000, and the number-average molecular weight was 300,000.

Melting point and ¹³ C-NMR measurements revealed that the polymer obtained was polystyrene with a syndiotacticity in racemic pentad of 98%.

Comparative Example 1 (1) Preparation of Contact Product of Aluminum Compound and Water In Example 1 (1), 17.8 g (71%) of copper sulfate pentahydrate was used.
Mmol) and the same operation as in Example 1 (1) was performed except that the reaction was performed at 0 ° C. for 6 hours.

As a result, 1.75 g of a contact product was obtained. The molecular weight of this product measured by the freezing point depression method was 360.

(2) Manufacture of styrene-based polymer The same operation as in Example 1 (2) except that the contact product obtained in Comparative Example 1 (1) was used in Example 1 (2). However, no polymer was formed.

Comparative Example 2 (1) Preparation of contact product of aluminum compound and water Example 1 (1) except that the reaction temperature was 10 ° C. and the reaction time was 6 hours in Example 1 (1). The same operation was performed to obtain a contact product having a molecular weight of 580 (freezing point depression method).

(2) Manufacture of Styrenic Polymer The same operation as in Example 1 (2) except that the contact product obtained in Comparative Example 2 (1) was used in Example 1 (2). Then, 3.3 g of a polymer was obtained. The polymer as the extraction residue had a syndiotacticity in racemic pentad of 90% and a weight average molecular weight of 40.
The number average molecular weight was 200,000.

Example 2 (1) Contact product of aluminum compound and water ((B)
Preparation of components) Example 1 (1) except that the reaction temperature was 60 ° C. and the reaction time was 24 hours.
The same operation as in (1) was performed.

As a result, 6.50 g of a contact product was obtained. The molecular weight of this product was 1900 as measured by the freezing point depression method.

(2) Manufacture of Styrene-based Polymer In Example 1 (2), the product obtained in Example 2 (1) above was used as the contact product as an aluminum atom.
The same operation as in Example 1 (2) was carried out except that 1 mmol of platinum was used, 0.06 mmol of pentamethylcyclopentadienyl titanium trimethoxide was used instead of tetraethoxy titanium, and that the reaction temperature was 70 ° C. It was

As a result, 37.9 g of a polymer was obtained. The syndiotacticity of the polymer as the extraction residue in racemic pentad was 97%, the weight average molecular weight was 1.8 million, and the number average molecular weight was 900,000.

Comparative Example 3 In Example 2 (2), the same operation as in Example 2 (2) was performed, except that the contact product obtained in Comparative Example 1 (1) was used. No coalescence was produced.

Example 3 In a reaction vessel having an internal volume of 500 ml, 50 ml of toluene, 3 mmol of the contact product (molecular weight 1900) obtained in the above Example 2 (1) as an aluminum atom, 3 mmol of triisobutylaluminum, pentamethylcyclopentadiene was used. 0.06 mmol of enyltitanium trimethoxide and 200 ml of styrene were added and a polymerization reaction was carried out at 70 ° C. for 1 hour. Example 1 below
The same operation as in (2) was performed to obtain 36.1 g of a polymer. Moreover, the syndiotacticity in the racemic pentad of the polymer remaining after extraction was 95%, and its weight average molecular weight was
The number average molecular weight was 800,000 and 400,000.

Example 4 In a reaction vessel having an internal volume of 500 ml, 50 ml of toluene, 3 mmol of the contact product (molecular weight 1900) obtained in Example 2 (1) above as an aluminum atom, 3 mmol of triisobutylaluminum, pentamethylcyclopentadiene was used. 0.06 mmol of phenyltitanium trimethyl and 200 ml of styrene were added and a polymerization reaction was carried out at 70 ° C. for 1 hour. Example 1 below
The same operation as in (2) was performed to obtain 36.1 g of a polymer. The syndiotacticity of the polymer as the extraction residue in racemic pentad was 97%, and its weight average molecular weight was
The number average molecular weight was 400,000, and the number average molecular weight was 200,000.

Example 5 In a reaction vessel having an internal volume of 500 ml, 50 ml of toluene, 6 mmol of the contact product (molecular weight 1100) obtained in the above Example 1 (1) as an aluminum atom, 0.06 mmol of pentamethylcyclopentadienyl titanium trimethyl, and styrene
200 ml was added and the polymerization reaction was carried out at 70 ° C. for 1 hour. Then, the same operation as in Example 1 (2) was performed to obtain 48.0 g of a polymer. The syndiotacticity of the polymer as the extraction residue in racemic pentad was 98%, the weight average molecular weight was 1.2 million, and the number average molecular weight was 600,000.

〔The invention's effect〕

As described above, the catalyst of the present invention has a remarkably high activity. Therefore, if a styrene-based monomer is polymerized using this catalyst, a styrene-based polymer with high syndiotacticity can be efficiently produced.

The syndiotactic styrene-based polymer thus obtained has excellent physical properties such as heat resistance and chemical resistance, and is widely and effectively used in various applications.

Claims (4)

[Claims] 1. A contact product of (A) a titanium compound and (B) an organoaluminum compound and water, the contact product having a molecular weight of 1000 to 2200 as measured by a freezing point depression method of a benzene solution. A catalyst for producing a styrene-based polymer, which is characterized by: 2. A contact product of (A) a titanium compound, (B) an organoaluminum compound and water, which has a molecular weight of 1000 to 2200 as measured by a benzene solution freezing point depression method, and (C) ) A catalyst for producing a styrenic polymer, which comprises an organoaluminum compound. 3. A method for producing a styrene-based polymer, which comprises using the catalyst according to claim 1 or 2 for polymerizing styrene and / or a styrene derivative. 4. The styrene-based polymer is a styrene-based polymer mainly having a syndiotactic structure.
The manufacturing method described.