JPH09291115A - Production of isobutylene polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an isobytylene polymer having a narrow molecular weight distribution fouling containers only little in industrial production and causing less cloudiness of products by using a specified new polymerization stabilizer in polymerizing a cationically polymerizable monomer containing isobutylene. SOLUTION: In producing an isobutylene polymer by polymerizing a cationically polymerizable monomer containing isobutylene in the presence of a compound represented by the formula: (CR<1> R<2> X)n R<3> [wherein X is a substituent selected among halogens, 1-6C alkoxyls and acyloxyls; R<1> and R<2> , which may be the same or different from each other, are each hydrogen or a 1-6C monovalent hydrocarbon group; R<3> is a polyvalent aromatic or aliphatic hydrocarbon group; and n is a natural number of 1-6C], a metal compound having an oxygen atom bonded to the metal atom and optionally a Lewis acid are used. It is desirable that the oxygen atom bonded to the metal atom of the metal compound is the oxygen atom of an alkoxyl and/or an acyloxyl.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polymer. More specifically, it relates to a method for obtaining an isobutylene-based polymer having a well-controlled structure by cationic polymerization.

[0002]

2. Description of the Related Art In recent years, also in the field of cationic polymerization, it has become possible to arbitrarily control the number average molecular weight of a polymer and to introduce various functional groups into the molecule. (Designed Polym by JP Kennedy and B. Ivan
ers by Carbocat-ionic Molecular Engineering: Theor
y and Practice, Carl Hanser Verlag, Munich 1992).
Of these, a terminal functional polyisobutylene-based polymer or a telechelic polyisobutylene-based polymer (hereinafter also referred to as an isobutylene-based polymer for simplicity) obtained from a cationically polymerizable monomer containing isobutylene has been well studied. This polymer is often obtained by cationically polymerizing a monomer such as isobutylene in the presence of the compound represented by the general formula (1).

(CR ¹ R ² X) _n R ³ (1) [wherein X is a halogen atom, a substituent selected from an alkoxy group having 1 to 6 carbon atoms or an acyloxy group, and R ¹ and R ² are each a hydrogen atom. Or, in a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ¹ and R ² may be the same or different, and R ³ is a polyvalent aromatic hydrocarbon group or a polyvalent aliphatic hydrocarbon group. , N is a natural number of 1 to 6. The compound represented by the general formula (1) serves as an initiator and is considered to be a starting point by forming a carbon cation in the presence of a Lewis acid or the like. At the end of the polymerization, it is considered that a functional group such as halogen resulting from the halogen atom of the initiator is introduced into the terminal of the polymer to form a telechelic polymer. Such an isobutylene-based polymer exhibits low water vapor permeability and excellent weather resistance, like ordinary non-telechelic polyisobutylene. On the other hand, since the telechelic polyisobutylene polymer is easily cured by crosslinking, necessary mechanical properties can be obtained even if the degree of polymerization of the isobutylene polymer before crosslinking is lower than that of ordinary polyisobutylene. Therefore, the drawbacks of the conventional non-telechelic polyisobutylene relating to moldability and processability are improved. The telechelic isobutylene-based polymer takes advantage of such characteristics and is used for adhesives, adhesives, paints, U
It can be used as a raw material for V / electron beam curable resin, coating material, elastic sealing material, sealing material for double glazing, electric / electronic sealing material, modifier for thermoplastic / thermosetting resin, and the like. It is also possible to synthesize a block copolymer that makes the most of the terminal functional group.

In order to satisfy these applications, it is desirable to use a polymer having a small amount of side reaction products and a narrow molecular weight distribution. For this purpose, it is effective to add a polymerization stabilizer to the polymerization system to some extent. Are known. Nuyk for example
En and Kennedy et al. reported the results of adding 2,6-di-tert-butylpyridine to the isobutylene polymerization system [Po.
lym. Bull., 8, 451 (1982), Polym. Bull., 20, 413 (19
88), J. Macromol. Sci.-Chem., A28 (2), 197 (1991).
etc〕. Also, Kaszas, Puskas, and Kennedy specify a polymerization stabilizer on a scale called the number of donors, and show a method of adding a compound having a number of donors within a certain range to a polymerization system (JP-A-1-318014).

As the polymerization stabilizer, substituted / unsubstituted pyridines, dimethylacetamide, dimethylsulfoxide, quaternary ammonium salts and the like are effective as the polymerization stabilizer. However, it is known that pyridines, dimethylacetamide, dimethylsulfoxide, etc., which are effective in stabilizing polymerization, generally have high basicity and form an insoluble complex with a Lewis acid as a polymerization catalyst. As a result, the polymer solution becomes cloudy or, in the extreme case, a large amount of precipitate is generated on the vessel wall. Polymers isolated from cloudy polymer solutions are often accompanied by objectionable cloudiness, which compromises the quality of the resulting product. Further, the deposits adhering to the vessel wall cannot be removed by simple washing such as solvent washing, and the heat removal by the jacket is hindered, which is a major obstacle in industrial production.

Further, many of these conventional stabilizers are generally highly water-soluble and have strong toxicity and odor, and care must be taken to prevent these stabilizers from leaking to the outside in the process of purifying the polymer. Furthermore, it is indispensable to take measures to avoid adverse effects on workers. That is, when washing the polymer solution in which the polymerization is completed with water or alkaline water, it is required to collect and remove these compounds eluted in the wastewater, but it is not easy to recover the water-soluble substance from the wastewater. ,
A large-scale device is required for detoxification, which causes an increase in cost. For example, because the odor of pyridine compounds is very strong, the effluent containing a small amount of pyridine also gives off an odor, and with quaternary ammonium salts, the substance that has moved to the wash water side has an adverse effect on microorganisms in the activated sludge. Problems such as difficulty in wastewater treatment can be cited.

The removal of the polymerization stabilizer component which dissolves in water is problematic as described above, but it is also problematic when it remains in the polymer solution. That is, if the washing with water is simplified or the number of washings is reduced in order to reduce the amount of treated waste water, extraction into water is not sufficiently performed, and the polymerization stabilizer tends to remain in the polymer solution. When the polymerization stabilizer accumulates in the solvent, the polymerization is significantly hindered. Therefore, when the solvent is recovered / reused from the polymer solution, the polymerization stabilizer must be completely removed, which is a heavy burden on the apparatus.

[0008]

In order to solve these problems, the present invention provides a new polymerization stabilizer and a method for producing an isobutylene polymer using the same.

[0009]

Means for Solving the Problems The present invention is to solve the above-mentioned problems, and is an isobutylene-based compound for polymerizing a cationically polymerizable monomer containing isobutylene in the presence of a compound represented by the following general formula (1). In the method for producing a polymer, the present invention relates to a method for producing an isobutylene-based polymer, which comprises coexisting a metal compound having an oxygen atom bonded to a metal atom and, if necessary, a Lewis acid.

(CR ¹ R ² X) _n R ³ (1) [wherein X is a halogen atom, a substituent selected from an alkoxy group having 1 to 6 carbon atoms or an acyloxy group, and R ¹ and R ² are each a hydrogen atom. Or, in a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ¹ and R ² may be the same or different, and R ³ is a polyvalent aromatic hydrocarbon group or a polyvalent aliphatic hydrocarbon group. , N represents a natural number of 1 to 6] The following publicly known technologies exist as technologies related to the present invention. First, in the reaction of silyldienol ether with acetal by Mukaiyama et al., Titanium tetrachloride was added to titanium (I
V) A method has been found in which the activity of titanium tetrachloride is weakened by combining it with isopropoxide to dramatically improve the yield (Mitsuaki Mukaiyama, Organic Synthesis Reaction, Tokyo Kagaku Dojin (1987), and among them). Cited documents). This method is important in the control of Lewis acidity,
It was never applied to polymer synthesis.

In an attempt to synthesize a block copolymer of polyisobutylene and poly (α-methylstyrene), Faust et al. First prepared isobutylene as 2,6-di-tert.
-Polymerization was carried out in the presence of butyl pyridine using titanium tetrachloride as a catalyst, and then titanium (IV) isopropoxide was added in an excess of 1.1 molar equivalents to titanium tetrachloride to deactivate titanium tetrachloride and to give tetraodor. A method of adding tin oxide and α-methylstyrene was reported [Polymer Preprint, 36 (2), 100 (1
995)]. Here, titanium (IV) isopropoxide is shown to deprive titanium tetrachloride of its catalytic ability, but it is regarded as a pretreatment for efficiently grafting α-methylstyrene to polyisobutylene. .
This is clear from the fact that 2,6-di-tert-butylpyridine is used in the step of polymerizing polyisobutylene having a uniform molecular weight distribution.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The metal compound having an oxygen atom bonded to a metal atom (hereinafter, also simply referred to as a metal compound) used in the present invention is characterized by having an oxygen atom bonded to a metal atom. It is preferable that the oxygen atom is further bonded to a carbon atom. More preferably, the oxygen atom bonded to the metal atom is an oxygen atom of an alkoxy group and / or an acyloxy group, and the average composition of the preferable metal compound is represented by the following general formula (2).

M ¹ (L ¹ ) _n (L ² ) _m (2) [wherein M ¹ is a metal atom, L ¹ is an alkoxy group or an acyloxy group, L ² is a halogen atom, and n and m are both 0. And an integer whose total corresponds to the valence of the metal atom M ¹ ] If a specific example is given, a metal alkoxide monomer obtained by completely reacting a metal halide with an alcohol,
A metal halogenoalkoxide monomer obtained by partially reacting a metal halide with an alcohol, a metal acylate monomer obtained from a metal halide and a carboxylic acid,
Examples thereof include an alkoxy group, an acyl group of these monomers, or a multimer in which a part of halogen is decomposed by water to be condensed, and / or a mixture thereof.

The alkoxy group on the metal atom preferably has 1 to 10 carbon atoms. Specifically, methoxy group, ethoxy group, (n-, iso-) propoxy group, (n-, s
ec-, tert-) butoxy group, pentyloxy group,
Examples thereof include a hexyloxy group, a phenyloxy group, a 2-ethylhexyloxy group, a heptyloxy group and an octyloxy group. It is also possible to use one having a larger carbon number, but since the boiling point of the alcohol generated by hydrolysis becomes high or the water solubility becomes low, the desired alkoxy group should be selected in view of the physical properties of the alcohol. Is good. Those which are industrially produced and can be suitably used in the present invention are ethoxy groups having 2 to 4 carbon atoms, propoxy groups, butoxy groups and the like. As the acyloxy group on the metal atom, those having 1 to 10 carbon atoms can be arbitrarily selected. The halogen atom is arbitrarily selected from fluorine, chlorine, bromine and iodine.

The metal atom may be bonded to an atom other than oxygen. A carbon atom can be mentioned as an example of an atom other than oxygen. Specifically, an organic group such as a methyl group, an ethyl group, a phenyl group, and a benzyl group on a metal has a σ
They may be bonded, or a (unsubstituted-, substituted-) cyclopentadienyl group or the like may be π-bonded. Further, a compound having a chelate bond between a metal atom and a substituent on the metal can also be used. Specific examples of the substituent capable of chelate coordination include glycols such as hexanediol and octanediol; β-such as acetylacetone.
Examples thereof include diketones; hydroxycarboxylic acids such as lactic acid, malic acid, tartaric acid and salicylic acid; ketoesters such as methyl acetoacetate and ethyl acetoacetate; and keto alcohols such as diacetone alcohol.

As the central metal of the metal compound used in the present invention, any metal element can be used. For example, titanium, zirconium and the like, Group 4B of the long periodic table, boron,
3A group such as aluminum and gallium, 4A group such as silicon, germanium, tin and lead, 5A group such as phosphorus, arsenic and antimony, 5B group such as vanadium, niobium and tantalum,
Examples include Group 8 elements such as iron, cobalt, and nickel. Preferably, titanium (III), titanium (IV), aluminum, boron, tin (II), tin (IV), zirconium, vanadium, antimony, iron and the like can be used as the central metal.

Although it is not possible to exemplify all combinations of substituents on these metals and central metals, titanium (III)
Methoxide, titanium (III) ethoxide, titanium (I
II) -n-propoxide, titanium (III) isopropoxide, titanium (III) -n-butoxide, titanium (III) -sec-butoxide, titanium (III)-
tert-butoxide, titanium (IV) methoxide, titanium (IV) ethoxide, titanium (IV) -n-propoxide, titanium (IV) isopropoxide, titanium (I
V) -n-butoxide, titanium (IV) -sec-butoxide, titanium (IV) -tert-butoxide and other titanium alkoxides; aluminum methoxide, aluminum ethoxide, aluminum-n-propoxide,
Aluminum alkoxides such as aluminum isopropoxide, aluminum-n-butoxide, aluminum-sec-butoxide, aluminum-tert-butoxide; borane methoxide, borane ethoxide, borane-n-propoxide, borane isopropoxide, borane- Borane alkoxides such as n-butoxide, borane-sec-butoxide, borane-tert-butoxide; tin methoxide, tin ethoxide, tin-n-propoxide, tin isopropoxide, tin-n-butoxide, tin-sec-butoxide, tin. Metal alkoxides such as tin alkoxides such as -tert-butoxide can be preferably used from the viewpoint of industrial availability.

When these metal alkoxides are hydrolyzed, the metal atoms bond with each other through an ether bond to form a multimer, and such a multimer can also be used in the present invention. The metal of the multimer may be a single metal or may contain two or more kinds of metals. In particular, an alkoxide composed of two kinds of metals is called a double metal type alkoxide, and many combinations have been devised as catalysts and adhesiveness-imparting agents used in various reactions. It is not preferable to mix alcohols and hydrogen halides that are eliminated during the multimerization into the cationic polymerization system.Therefore, when a large amount of these low-molecular components are contained, it is necessary to carry out an operation such as distillation before using them in the present invention. It is desirable to remove it. The method for producing the metal compound used in the present invention is not particularly limited, but for example, it is a compound that can be derived from a metal halide.

The monomer polymerized in the present invention is a cationically polymerizable monomer containing isobutylene and may or may not contain a monomer other than isobutylene.
Specifically as a monomer other than isobutylene, a known cationically polymerizable monomer, for example, propene, 1-butene,
2-butene, 2-methyl-1-butene, 3-methyl-1
Aliphatic olefins such as butene, pentene, hexene, cyclohexene, vinylcyclohexane, 5-ethylidene norbornene, indene and β-pinene; dienes such as butadiene, isoprene, cyclopentadiene, dicyclopentadiene; styrene, α-methylstyrene ,
Styrenes such as p-halogenostyrene and p-alkoxystyrene; methyl vinyl ether, ethyl vinyl ether, (n-, iso) propyl vinyl ether, (n-,
Examples thereof include vinyl ethers such as sec- and tert-) butyl vinyl ether; and vinylcarbasol.

In the present invention, a Lewis acid catalyst may coexist if necessary. Any catalyst that can be used for cationic polymerization may be used as such a catalyst, such as TiCl ₄ , T
iBr ₄ , BCl ₃ , BF ₃ , SnCl ₄ , VCl ₅ , F
Metal halides such as eCl ₃ , ZnBr ₂ , AlCl ₃ and AlBr ₃ ; and organic metal halides such as Et ₂ AlCl and EtAlCl ₂ can be preferably used.
Of these, TiCl ₄ , BCl ₃ and SnCl ₄ are preferable in view of their ability as catalysts and industrial availability.
The central metal of the Lewis acid catalyst may be the same as or different from the central metal of the metal compound, but the same metal atom is preferable in terms of post-polymerization treatment.

As described above, the compound represented by the general formula (1) used in the present invention serves as an initiator and is considered to be a starting point by forming a carbon cation in the presence of a Lewis acid or the like. At the end of the polymerization, it is considered that a functional group such as halogen resulting from the halogen atom of the initiator is introduced into the terminal of the polymer to form a telechelic polymer. Examples of the compound of the general formula (1) used in the present invention include the following compounds.

(2-Chloro-2-propyl) benzene C ₆ H ₅ C (CH ₃ ) ₂ Cl 1,4-bis (2-chloro-2-propyl) benzene 1,4-Cl (CH ₃ ) ₂ CC ₆ H ₄ C (CH ₃ ) ₂ Cl 1,3-bis (2-chloro-2-propyl) benzene 1,3-Cl (CH ₃ ) ₂ CC ₆ H ₄ C (CH ₃ ) ₂ Cl 1,3, 5- tris (2-chloro-2-propyl) benzene _{1,3,5 - ((ClC (CH 3} ) 2) 3 C 6 H 3 1,3- bis (2-chloro-2-propyl) -5- (T
ert- butyl) benzene _{1,3 - ((C (CH 3} ) 2 Cl)
_{2 -5- (C (CH 3)} 3) C 6 H 3, bis (2-chloro-2-propyl) benzene bis (alpha
-Chloroisopropyl) benzene, also called dicumyl chloride.

The present invention can be carried out in a suitable solvent as needed, and any solvent can be used without particular limitation as long as it does not inhibit the cationic polymerization. Specifically, halogenated hydrocarbons such as methyl chloride, dichloromethane, chloroform, ethyl chloride, dichloroethane, n-propyl chloride and n-butyl chloride can be used, and more preferably composed of only a solvent containing no halogenated hydrocarbon. Preferably. Specific examples of preferable solvents include benzene, toluene, xylene,
Benzene / alkylbenzenes such as ethylbenzene, propylbenzene, butylbenzene; ethane, propane,
Linear aliphatic hydrocarbons such as butane, pentane, hexane, heptane, octane, nonane, decane; 2-methylpropane, 2-methylbutane, 2,3,3-trimethylpentane, 2,2,5-trimethylhexane And branched aliphatic hydrocarbons such as; cycloaliphatic hydrocarbons such as methylcyclohexane and ethylcyclohexane; and paraffin oil obtained by hydrogenating and refining petroleum fractions.

Each of these solvents can be used alone for polymerization, but a mixture can be preferably used to balance the polymerization characteristics and the solubility. A particularly preferred solvent system is a mixture of aromatic hydrocarbons such as toluene and aliphatic or alicyclic hydrocarbons. Considering the viscosity of the obtained polymer solution and the ease of heat removal, the amount of the solvent used is such that the concentration of the polymer is 1 to 50 wt%, preferably 5 to 30 wt%.
Will be determined.

The amount of each component used can be appropriately designed depending on the characteristics of the intended polymer. First, the molecular weight of the obtained polymer is determined by the molar equivalent relationship between the cationically polymerizable monomer and the compound of the general formula (1). Usually, the ratio is set so that an isobutylene polymer having a number average molecular weight of 1,000 or more and less than 30,000 is produced. Next, the amount of the metal compound used can be determined in consideration of the balance between the polymerization stabilizing effect such as heat generation suppression and unwanted chain transfer reaction suppression and the polymerization rate. The optimum amount varies depending on the chemical structure of the metal compound, but when the metal compound is a monomer, it is preferably 0.001 to 10 molar equivalents, more preferably the compound represented by the general formula (1). In the range of 0.005 to 5, more preferably 0.01 to 0.
Used in the range of 4. In the case where the metal compound is a multimer, the preferred amount of use may vary depending on the degree of condensation,
It can be roughly calculated based on the metal content and finally determined by experiment. If the molar equivalent of the metal compound is too large, the polymerization is hindered and the conversion rate of the monomer is lowered. On the contrary, if it is too small, a sufficient polymerization stabilizing effect cannot be obtained.

In the present invention, a Lewis acid can coexist if necessary, and the Lewis acid can be mixed with a metal compound in advance, or the Lewis acid can be charged into a reaction vessel charged with other raw materials at the end. You can also The molar equivalent of the Lewis acid and the metal compound is determined in consideration of the activity of the Lewis acid catalyst and the desired polymerization rate, but generally (Lewis acid) / (metal compound) is 0.01 to 100, preferably It is in the range of 0.2 to 10.

In the actual polymerization, the components are mixed under cooling, for example, at a temperature of -100 ° C or higher and lower than 0 ° C. A particularly preferable temperature range is -30 ° C to -80 ° C in order to balance the energy cost and the stability of polymerization. The method of adding each component is not particularly limited, and the addition of the monomer may be performed in a divided manner, or the reaction mode may be variously changed from a batch system to a continuous system.

According to the production method of the present invention, a polymer having a halogen atom at the terminal of the polymer chain can be obtained, but when the halogen atom is converted into an unsaturated group, the polymer has an unsaturated group at the terminal. This polymer is further disclosed in JP-A-63-6041.
It is a convenient intermediate for introducing a crosslinkable silicon group or for producing a block copolymer as disclosed in Japanese Patent Laid-Open Publication No. H11-242242. As a method of converting a halogen atom into an unsaturated group, there is a method of reacting a compound represented by the general formula (3) disclosed in JP-A-63-105005. M ² R ¹ R ² R ³ R ⁴ (3) [wherein M ² is a silicon or tin atom, R ¹ is an allyl group or a vinyl group, and R ² , R ³ and R ⁴ are a methyl group or an ethyl group, respectively. May be different from each other.] In the production method of the present invention, the compound represented by the general formula (3) is added to the isobutylene-based polymer obtained by the reaction without once isolating the polymer, and the reaction is performed. Carbon-carbon unsaturated groups can also be easily introduced into the polymer. Specific examples of the general formula (3) include allyltrimethylsilane, vinyltrimethylsilane, allyltrimethyltin, vinyltrimethyltin, and the like, and these compounds are different from the polymerization initiation point of the compound of the general formula (1). A molar equivalent or more, preferably 1.0 to 1.5 molar equivalent is used. The polymer in which the carbon-carbon unsaturated group is introduced deactivates the Lewis acid catalyst,
After removing by washing with water, the solvent is distilled off to be isolated.

According to the present invention, the compound having a lower boiling point than the solvent can be removed from the recovered solvent by distillation and reused as the next polymerization solvent. The metal compound used in the present invention is decomposed when the catalyst is deactivated and washed with water to give only an alcohol or a carboxylic acid and an inorganic salt. The inorganic salt is removed at the same time as the catalyst is deactivated and removed by washing with water, and most of the alcohol and carboxylic acid are removed by washing with water. The trace amount of alcohol and carboxylic acid will be removed from the polymer when the solvent is distilled off, and will be contained in the recovered solvent. Can be easily removed by distillation. Distillation is carried out to remove various low boiling point components mixed in the recovered solvent and to stably carry out the polymerization of the next batch.However, alcohol is removed at the same time in the process, and the process is newly added. Does not give a burden. As an example of the selection of the alkoxy group, for example, when the main solvent is toluene (boiling point 110 ° C.), a methoxy group,
It is selected from either an ethoxy group or a propoxy group. It should be noted that the distillation here may be of a batch type or a continuous type as long as the above purpose can be achieved.

[0030]

The present invention will be described more specifically with reference to the following examples. In this example, the produced halogen-terminated polymer is converted to an allyl group-terminated polymer using the compound represented by the general formula (3). Evaluation of the converted polymer is Mw / Mn
(Molecular weight distribution) and Fn ^* (vinyl) (number of vinyl groups per polymer molecule, calculated by the following calculation) were evaluated. The smaller the Mw / Mn value is, the smaller the molecular weight distribution is, which means that the polymer is easy to handle, and Fn ^* (vinyl) is the polymer in this example.
Since the polymer is linear, a value closer to 2 indicates that there are no by-products.

The molecular weights shown in this Example are the GPs shown below.
It was measured by C and ¹ H-NMR. This molecular weight is convenient, unlike the actual value. The molecular weight distribution was measured by GPC. In addition, Fn ^* (vinyl) is a polymer ¹ H-NM
After measuring R, it was calculated by the following calculation method. GPC analysis: System: Waters system (pump 600E, differential refractometer 401), column: Showa Denko KK Shodex K-804 (polystyrene gel), mobile phase: chloroform, number average molecular weight, etc. in polystyrene conversion . ¹ H-NMR (300 Hz): Ge manufactured by Varian
mini-300, measurement solvent; carbon tetrachloride + heavy acetone.

Determination of molecular weight by Fn ^* (vinyl) and ¹ H-NMR: 1) In NMR, the integral value of the peak attributed to the H atom contained in each functional group is determined. 2) Divide the integrated value obtained in 1) by the number of H atoms of each functional group. -3) Obtain the ratio of the polymer main chain unit and the initiator unit, and multiply this by the molecular weight 56 of isobutylene to obtain Mn.
(NMR). 4) Divide the molecular weight Mn (GPC) obtained from GPC by the molecular weight 56 of the isobutylene group to obtain the number of isobutylene units contained in one molecule of the oligomer. Let this be n ^* . 5) Divide the value of corresponding to the isobutylene group by n ^* . ―
6) Divide the value of corresponding to the vinyl group by. This is defined as the number Fn ^* (vinyl) of functional groups per one molecule of oligomer.

Incidentally, Fn (vinyl), which is a value obtained by dividing the value corresponding to the vinyl group by the value corresponding to the initiator, may be used as a standard for the amount of vinyl groups present in the polymer. The values are also shown. This value is ¹ H-NM
It is a value obtained only from R and easily obtained.
^* (Vinyl) is considered to be more accurate as a measure of the amount of vinyl groups. The following relationship is established between Fn (vinyl) and Fn ^* (vinyl).

Fn ^* (vinyl) = Fn (vinyl) × Mn
(GPC) / Mn (NMR) Example 1 After replacing the inside of a polymerization vessel of a 500 mL separable flask with nitrogen, ethyl cyclohexane (dried by molecular sieves 3A) was placed in the vessel using a syringe.
20 mL and toluene (dried by leaving it with Molecular Sieves 3A for 1 night or more) 80
mL, p- [bis (α-chloroisopropyl) benzene] (hereinafter abbreviated as p-DCC for simplicity) 0.555 g
(2.4 mmoL) was added. Next, after connecting a Teflon feed tube to a pressure-resistant glass liquefaction collection tube with a three-way cock containing 32.6 mL of isobutylene monomer, the polymerization container was placed in a -70 ° C dry ice / ethanol bath and cooled, Isobutylene monomer was fed into the container by a nitrogen pressure using a liquid feeding tube. The inside of the container was agitated with a mechanical stirrer to keep nitrogen constantly flowing. Next, titanium (IV) isopropoxide 0.0
68 g (0.24 mmoL) was added. Next, 0.658 ml (6.0 mmoL) of titanium tetrachloride was added to initiate polymerization. After stirring at the same temperature for 120 minutes from the start of polymerization, allyltrimethylsilane 0.658 g (5.76 m)
(moL) was added, and an allyl group introduction reaction was performed. After a reaction time of 120 minutes, 50 mL of the reaction solution was sampled,
After washing 3 times with 100 mL of water, the solvent was distilled off to obtain an isobutylene polymer. The results are shown in Table 1.

Table 1 GPC analysis value NMR analysis value Mn Mw / Mn Mn Fn ^* (vinyl) Fn (vinyl) 9800 1.36 11000 1.87 2.11 Example 2 The amount of titanium (IV) isopropoxide used was determined. 0.102
An isobutylene-based polymer was obtained in the same manner as in Example 1 except that the addition of allyltrimethylsilane was omitted, with g (0.36 mmoL). Example 3 The amount of titanium (IV) isopropoxide used was 0.068.
An isobutylene-based polymer was obtained in the same manner as in Example 2 except that g (0.24 mmoL) was used. Example 4 Instead of titanium (IV) isopropoxide, titanium (I
V) -n-butoxide 0.163 g (0.48 mmo
An isobutylene polymer was obtained in the same manner as in Example 2 except that L) was used. Comparative Example 1 An isobutylene polymer was obtained in the same manner as in Example 1 except that the metal compound was not added.

The results of Examples 2 to 4 and Comparative Example 1 are summarized in Table 2. Table 2 No. GPC analysis value Mn Mw / Mn Example 2 9100 1.42 Example 3 8800 1.36 Example 4 9300 1.40 Comparative Example 1 8300 3.83 Example 5 In a polymerization container of a 2000 mL separable flask. Was replaced with nitrogen, and then 210 mL of ethylcyclohexane and 840 mL of toluene, p-DC were placed in a container using a syringe.
C 5.779 g (25 mmoL), isobutylene monomer 340 mL, titanium (IV) isopropoxide 0.7
1 g (2.5 mmoL) was added. Next, 6.85 mL (62.5 mmoL) of titanium tetrachloride was added to initiate polymerization. 120 minutes after the initiation of polymerization, 6.86 g (60 mmoL) of allyltrimethylsilane was added to carry out a reaction for introducing an allyl group at the polymer terminal.

After 120 minutes of reaction time, 50 mL of reaction solution
Was sampled and washed three times with 100 mL of water,
The solvent was distilled off to obtain an isobutylene polymer. The polymer solution was always transparent during the reaction, and almost no deposit was observed on the container wall after the contents were discharged.
Table 3 shows the analysis results of the obtained isobutylene polymer.

Table 3 GPC analysis value NMR analysis value Mn Mw / Mn Mn Fn ^* (vinyl) Fn (vinyl) 10100 1.31 11300 1.96 2.19 Example 6 The solvent used in Example 5 was recovered, After distillation, it was used again for polymerization.

After replacing the inside of the polymerization vessel of a 500 mL separable flask with nitrogen, the recovered solvent (dried by Molecular Sieves 3A) was placed in the vessel using a syringe.
33.15 g (toluene / ethylcyclohexane mixing ratio of 2.723 by weight) was added to ethylcyclohexane 8.
71 mL and toluene 52.03 mL were added to adjust the mixed solvent composition. p-DCC 0.555g (2.4mm
ol), isobutylene monomer 32.6 mL, titanium (IV) isopropoxide 0.068 g (0.24 mm
oL) was added, and titanium tetrachloride (0.658 mL, 6.0 m) was added.
(moL) was added to initiate polymerization. 12 from the start of polymerization
After 0 minutes, 0.658 g of allyltrimethylsilane (5.
76 mmoL) was added to carry out an allyl group introduction reaction, and an isobutylene polymer was obtained in the same manner as in Example 5.

The results of the analysis are shown in Table 4. Table 4 GPC analysis value NMR analysis value Mn Mw / Mn Mn Fn ^* (vinyl) Fn (vinyl) 9600 1.39 10400 1.92 2.07 Comparative Example 2 After polymerization using α-picoline as a polymerization stabilizer, The solvent was recovered, distilled and used again for polymerization. The amount of α-picoline used was 0.2 in molar equivalent with respect to p-DCC.

After replacing the inside of the polymerization vessel of a 500 mL separable flask with nitrogen, the recovered solvent (dried by molecular sieves 3A) was placed in the vessel using a syringe.
The solvent ratio was adjusted by adding 77.96 g (the mixing ratio of toluene / ethylcyclohexane of 3.947 by weight) and 8.26 mL of toluene. 0.555 g of p-DCC (2.
4mmoL), isobutylene monomer 32.6mL, α
-Add 0.045 g (0.48 mmoL) of picoline,
Polymerization was initiated by adding 0.658 mL (6.0 mmoL) of titanium tetrachloride. After a reaction time of 120 minutes, 0.658 g (5.76 mmoL) of allyltrimethylsilane was added, and an isobutylene polymer was obtained in the same manner as in Example 5.

The polymer solution showed an ocher turbidity, and brown deposits were found on the container wall after being dispensed. The analysis results are shown in Table 5. The obtained polymer was inferior to Example 6 in the rate of introduction of double bonds at the terminals. Table 5 GPC analysis value NMR analysis value Mn Mw / Mn Mn Fn ^* (vinyl) Fn (vinyl) 10000 1.39 10700 1.62 1.73

[0043]

Industrial Applicability According to the method of the present invention, it is possible to control the polymerization of the cationically polymerizable monomer containing isobutylene and to give living-like polymerization conditions. Specifically, by adding a metal compound having an oxygen atom bonded to a metal atom to the polymerization system, the β-position proton of the growing carbon cation is eliminated or the growing end reacts with an aromatic ring contained in the initiator or solvent. Then, the termination of the polymerization can be suppressed as much as possible. The quality of such polymerization control can be determined most simply from the molecular weight distribution (Mw / Mn) of the polymer obtained, and also from the internal temperature rise behavior immediately after the initiation of polymerization. According to the present invention, a polymer having a narrow molecular weight distribution (Mw / Mn <1.5) can be obtained, and the increase in internal temperature can be suppressed to a small level.

As a method that brings about an effect close to the present invention,
1) A compound having high basicity as described above; for example, in addition to a method of adding pyridines, dimethylacetamide, dimethylsulfoxide, etc. to the polymerization system, 2) Acetic acid ester of tertiary alcohol (tROOCMe) as a starting point of polymerization
And polymerization using a halogenated solvent and boron trichloride using a tertiary alkyl methyl ether (tROMe) (R. Faust and JP Kennedy, Polym. Bull. 15, 417 (1
986); J. Polym. Sci., Part A, Polym. Chem., 25, 1847
(1987)) are known. The inventors of these existing technologies call the former method an external addition type and the latter an internal addition type.

The former technique has a problem of generation of an insoluble complex and wastewater treatment as described above, and has many problems in industrial production. Capital investment is required to take sufficient measures against toxicity and odor. The latter technology is characterized in that it does not require the addition of substances with strong toxicity or odor, and that the final decomposition products are methanol and acetic acid, so the load of wastewater treatment is light. On the other hand, however, since the initiator used is limited, the Lewis acid species that can be used in combination is extremely limited. Further, a technique capable of freely controlling the polymerization rate is indispensable in considering the scale-up of the polymerization operation, but it is fatal that the amount of the polymerization stabilizer cannot be freely changed as in the external addition type. This inevitably determines the amount of initiator that must be used to achieve the desired degree of polymerization, while reducing the amount of Lewis acid catalyst to suppress the polymerization rate, especially during scale-up. This is because the polymerization itself does not proceed. Further, there is a drawback that the synthesis route of the initiator is complicated and the cost is high.

In the present invention, the addition amount of the polymerization stabilizer can be freely adjusted in order to achieve a desired polymerization rate and a desired molecular weight distribution. There are no restrictions on the types of initiators and Lewis acids found in the internal addition type, while the decomposition products are neutral inorganic salts and alcohols, so the treatment of wastewater is extremely easy. As described above, the present invention successfully takes advantage of the advantages of the external addition type and the internal addition type, but the present invention has several additional features. That is, one feature of the present invention is that the polymerization system is completely transparent and does not cause turbidity or precipitation. The reason why the conventional polymerization stabilizer recommended by Kennedy et al. Makes the polymerization system turbid is not necessarily understood, but it is presumed that some insoluble complex is formed. The occurrence of turbidity and precipitation of the system poses a very serious problem in terms of product quality as described above. According to the method of the present invention, the polymerization system does not show any turbidity, and the purified polymer does not show any turbidity.

In the case of cationic polymerization using a Lewis acid, the reaction is usually carried out under cooling, but the precipitate adhering to the vessel wall cannot be easily removed, which hinders heat removal from the jacket. Furthermore, the present inventors have discovered that the precipitated component attached to the vessel wall hinders the next polymerization, and removal of the vessel wall attached matter has been a problem in the actual production operation. According to the present invention, since the polymerization system is transparent and does not form deposits on the vessel wall, the amount of solvent for washing the reactor can be reduced or omitted. It was an unexpected effect that the polymerization stabilizer of the present invention made the system transparent, and thus contributes to simplification of the whole process.

The second feature of the present invention is that after polymerizing a cationically polymerizable monomer containing isobutylene, the compound represented by the general formula (3) is added and reacted without once isolating the polymer, The point is that a carbon-carbon unsaturated group can be introduced at the polymer terminal. By using the component represented by the general formula (3), allyl and / or
Alternatively, a vinyl anion can be reacted. An interesting point is that the polymerization conditions of the cationically polymerizable monomer and the introduction of the carbon-carbon double bond to the growing terminal can be achieved under the same conditions. The introduced carbon-carbon double bond can be utilized not only as a crosslinking point but also for the introduction of another functional group.

The third feature of the present invention is that the compound having a lower boiling point than the solvent is removed from the recovered solvent by distillation and can be reused as the next polymerization solvent. According to the studies conducted by the present inventors so far, it was found that various by-products were mixed in the recovered solvent. It was found that some of them significantly hinder the polymerization of the next batch. If the inhibitor is a compound having a boiling point lower than that of the polymerization solvent, it can be removed by subjecting the recovered solvent to simple distillation. However, on the contrary, if it is a high boiling point solvent, the polymerization solvent as the main component must be cooked up by distillation in order to remove a generally small amount of inhibitory component,
There is no choice but to call it a method with a large energy loss.

Conventionally known polymerization stabilizers such as 2,6-di-tert-butylpyridine, 2,6-dimethylpyridine, (α-, β-, γ-) picoline, pyridine, and other compounds having a high boiling point and stable. When used, these compounds are stable in the process of producing the polymer and may remain in the recovered solvent without being removed by washing the polymer solution with water.
If the boiling point of these compounds is higher than that of the polymerization solvent, removal by distillation is disadvantageous. On the other hand, the polymerization stabilizer used in the present invention decomposes in the steps of deactivating the catalyst and washing with water to give only a water-soluble substance such as alcohol and an inorganic salt. In the case of alcohol, particularly low-grade alcohol has high water solubility and is removed in the washing step, so that it hardly remains in the recovered solvent. In addition, a small amount of remaining alcohol can be removed by simple distillation together with other low boiling impurities in the distillation step. One of the advantages of the present invention is that the solvent having the optimum composition can be selected without paying attention to the boiling point of the polymerization solvent.

As described above, according to the method of the present invention, an isobutylene polymer having a small molecular weight distribution can be produced by using a polymerization stabilizer having low toxicity and odor. In particular, when industrial production is performed, it is effective in reducing the stain on the container and suppressing the turbidity of the product. Also, the reaction of introducing a carbon-carbon double bond at the terminal can be carried out under the same conditions without once isolating the polymer. The resulting carbon-carbon unsaturated group-containing polymer is cured by crosslinking or the introduction of another functional group,
It can be used for synthesis of block copolymers. Furthermore, by removing the compound having a lower boiling point than the solvent by distillation from the solvent recovered after the completion of the reaction, it can be reused as the next polymerization solvent. This is a great advantage in the operation of the industrial process.

Claims (12)

[Claims] 1. A method for producing an isobutylene-based polymer, which comprises polymerizing a cationically polymerizable monomer containing isobutylene in the presence of a compound represented by the following general formula (1):
A method for producing an isobutylene polymer, which comprises allowing a metal compound having an oxygen atom bonded to a metal atom and a Lewis acid to coexist as necessary. (CR ¹ R ² X) _n R ³ (1) [wherein X is a halogen atom, a substituent selected from an alkoxy group having 1 to 6 carbon atoms or an acyloxy group, and R ¹ and R ² are each a hydrogen atom or a carbon number. 1 to 6 monovalent hydrocarbon groups, R ¹ and R ² may be the same or different, R ³ is a polyvalent aromatic hydrocarbon group or a polyvalent aliphatic hydrocarbon group, and n is A natural number of 1 to 6 is shown. ] 2. The metal atom of the metal compound has a long periodic table 4
The method according to claim 1, wherein the metal is a group B, 3A group, 4A group, 5A group, 5B group, or 8 group metal. 3. A metal atom comprising titanium (III) or titanium (I)
V), aluminum, boron, tin (II), tin (I
The production method according to claim 2, which is one or more metal atoms selected from the group consisting of V), zirconium, vanadium, antimony, and iron. 4. The method according to claim 1, wherein the oxygen atom bonded to the metal atom in the metal compound is further bonded to the carbon atom. 5. The method according to claim 4, wherein the oxygen atom bonded to the metal atom in the metal compound is an oxygen atom of an alkoxy group. 6. The method according to claim 4, wherein the oxygen atom bonded to the metal atom in the metal compound is an oxygen atom of an acyloxy group. 7. The method according to claim 4, wherein the average composition of the metal compounds is represented by the following general formula (2). M ¹ (L ¹ ) _n (L ² ) _m (2) [In the formula, M ¹ is a metal atom, L ¹ is an alkoxy group or an acyloxy group, L ² is a halogen atom, and n and m are not 0 and are the total thereof. Is an integer corresponding to the valence of the metal atom M] 8. The method according to claim 1, wherein titanium (IV) alkoxide is used as the metal compound having an oxygen atom, and titanium tetrachloride is used as the Lewis acid. 9. A compound represented by the general formula (1) is bis (2
-Chloro-2-propyl) benzene [C ₆ H ₄ (C (CH
_The method according to claim 1, which is a compound represented by ₃ ) ₂ Cl) ₂ ]. 10. The method according to claim 1, wherein a solvent is further used. 11. The method according to claim 10, wherein the solvent is a halogen-free hydrocarbon. 12. The method according to claim 1, wherein the polymerization temperature is −100 ° C. or higher and 0 ° C. or lower.