JP2003268029A - Method for producing acrylic acid ester polymer and block copolymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an efficient method for producing an acrylic acid ester polymer capable of polymerizing at a relatively high polymerization temperature and in a high polymerization rate, and also having a high living property. <P>SOLUTION: This method for producing the acrylic acid ester polymer is to perform a reaction of an organo-oxymetallic compound expressed by formula (1): ROM (wherein, M is an alkali metal; and R is a chain state hydrocarbon or cyclic hydrocarbon group) and an organoaluminum compound with the acrylic acid ester for performing an anionic polymerization. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an acrylic acid ester polymer and a block copolymer.

[0002]

2. Description of the Related Art Acrylic acid ester polymers and block copolymers thereof are used for paints, adhesives, foams, cushioning materials, vibration damping materials, vibration damping materials, sealing materials, because of their adhesiveness and chemical degradability. It is used for various purposes as raw materials and additives in the production of sealing materials. In recent years, a polymer having a narrow molecular weight distribution including a desired molecular weight has been required from the viewpoint of functionalizing a polymer material. Living anionic polymerization using an organometallic compound as an initiator is effective as a method for synthesizing these polymers, and various reports have been made.

For example, when an organic lithium compound is used as a polymerization initiator and lithium 2- (2-methoxyethoxy) ethoxide is used as an additive and solution polymerization is carried out under a low temperature condition such as -78 ° C, living polymerization proceeds. , Acrylic acid ester polymer can be obtained (Macromolecules 27, 4
890, 1994; Journal of Polymer Science: P
art A: Polymer Chemistry 35, 361, 1997
Year). However, in order to maintain this living property, it is necessary to carry out the polymerization at a low temperature of −78 ° C., and at a relatively high polymerization temperature of about 0 ° C., the living property may be lowered and the polymerization may not be controlled. There was a problem.

[0004] Furthermore, the Polymer Society of Japan
Rints, Japan) 46, No. 7, page 1081, 1997, using t-butyllithium as a polymerization initiator, methylbis (2,6-di-t-butylphenoxy) aluminum or ethylbis (2,6-di-t). When -butylphenoxy) aluminum is used as an additive and solution polymerization is carried out at -60 ° C or -78 ° C, living polymerization of acrylic acid ester proceeds, but in order to maintain this living property, the polymerization is carried out under low temperature conditions. Since it is necessary, there is a problem that the polymerization rate may slow down.

Also, although different from the polymerization of acrylic acid ester, the polymerization of methacrylic acid ester using potassium t-butoxide as an initiator is described in Shiro Kobayashi, Catalysi.
s inPrecision Polymerization, WILEY, 285 pages
However, the yield of the polymer produced is about 40%.
And the molecular weight distribution was 2.0 and the living property was low. As a result of applying this initiator system to the polymerization of acrylic acid ester, the yield was improved, but the molecular weight distribution was 1.6.
6 and the living property was low.

[0006]

As described above, in an anionic polymerization system using organic lithium as a polymerization initiator, living polymerization proceeds at a low temperature of about -78 ° C.
The polymerization rate is slow, and if the polymerization temperature is further increased, the living property is greatly reduced. In addition, the initiator system using potassium t-butoxy had a low living property.

Therefore, an object of the present invention is to provide an efficient method for producing an acrylic acid ester polymer and a block copolymer which can be polymerized at a relatively high polymerization temperature with a high polymerization rate and a high living property. is there.

[0008]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above-mentioned problems of the prior art, the present inventors use an anionic polymerization disclosing agent comprising a specific organic oxymetal compound and an organic aluminum compound. Therefore, it was found that the acrylic ester polymer and the block copolymer can be efficiently produced.

That is, the method for producing an acrylic acid ester polymer of the present invention is a method for producing an acrylic acid ester polymer by anionically polymerizing an acrylic acid ester as a monomer using an anionic polymerization initiator, As an anionic polymerization initiator, an organic oxy represented by the formula (1): R-OM (in the formula (1), M is an alkali metal and R is a chain hydrocarbon group or a cyclic hydrocarbon group). It is characterized in that a metal compound and an organoaluminum compound are used in combination.

Further, the method for producing a block copolymer of the present invention is characterized in that after the acrylic ester is polymerized by the above-mentioned production method, the methacrylic ester is further added and polymerized.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The acrylic acid ester as a monomer used in the production method of the present invention undergoes anionic polymerization with high living property by the reaction of the organic oxymetal compound of the above formula (1) and the organic aluminum compound. Is something that can be done. Examples of such acrylates include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-acrylate.
-Butyl, isoamyl acrylate, lauryl acrylate, phenyl acrylate, benzyl acrylate, cyclohexyl acrylate, glycidyl acrylate, 2-ethylhexyl acrylate, 4-t-butylcyclohexyl acrylate, tricyclodecanyl acrylate, acrylic Examples thereof include dicyclopentadienyl acid and adamantyl acrylate. Among these, when properties such as transparency and availability are required, it is preferable that the alkyl group having 1 to 6 carbon atoms be substituted with the carboxy group of acrylic acid, and among these, isopropyl acrylate and acrylic Particularly preferred are secondary and tertiary acrylic acid esters such as amyl acid, t-butyl acrylate, cyclohexyl acrylate and the like.

The acrylic ester may be used alone or as a monomer by combining two or more different acrylic esters.

Further, other copolymerizable monomers may be used in combination with the acrylic acid ester, and may be copolymerized with the acrylic acid ester, depending on the application and quality requirements of moldability. Typical examples of copolymerizable anionic polymerizable monomers include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, and 2-ethyl methacrylate. Xyl, lauryl methacrylate, cesyl methacrylate, n-stearyl methacrylate, glycidyl methacrylate, allyl methacrylate, 2-methoxyethyl methacrylate, 3-methoxybutyl methacrylate, trimethoxysilylpropyl methacrylate, trifluoroethyl methacrylate. Methacrylic acid esters such as trimethylsilyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate and isobornyl methacrylate; N-isopropylacrylamide, Nt-butylacrylamide, , N
-Acrylamide compounds such as dimethyl acrylamide and N, N-diethyl acrylamide; N-isopropyl methacrylamide, Nt-butyl methacrylamide,
Examples thereof include methacrylamide compounds such as N, N-dimethylmethacrylamide and N, N-diethylmethacrylamide. These anion-polymerizable monomers can be used alone or in combination of two or more different kinds.

When other monomers are used in combination with the acrylic acid ester, the proportion of the monomers other than the acrylic acid ester in the total monomers should be within the range of not more than 20 mol%. It is preferable for obtaining a good living property.

It is preferable that the monomer used in the present invention is sufficiently dried in advance under an inert gas stream or the like from the viewpoint of smoothly proceeding the polymerization reaction. In the drying treatment, calcium hydride or molecular is used. Dehydrating / drying agents such as sieves and activated alumina are preferably used.

The organic oxymetal compound which is one component of the anionic polymerization initiator in the present invention is the compound represented by the above formula (1).

Examples of the chain hydrocarbon group as R in the above formula (1) include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl and neopentyl, n-. Hexyl or the like having 1 to 30 carbon atoms, preferably 1 to 20 linear or branched alkyl group; vinyl, allyl, isopropenyl or the like having 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms A chain or branched alkenyl group; ethynyl, propargyl and the like having 2 to 30 carbon atoms, preferably 2 to 2 carbon atoms
A straight-chain or branched alkynyl group of 0 can be mentioned.

Further, examples of the cyclic hydrocarbon group as R in the above formula (1) include a cycloalkyl group and an aryl group.

Examples of the above cycloalkyl group include:
Cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl and the like have 3 to 3 carbon atoms
0, preferably 3 to 20 saturated cycloalkyl groups,
Examples thereof include unsaturated cycloalkyl groups having 5 to 30 carbon atoms such as cyclopentadienyl, indenyl and fluorenyl, and substituted cycloalkyl groups such as 4-t-butylcyclohexyl and 1-methyl-adamantyl.

Examples of the aryl group include aryl groups having 6 to 30, preferably 6 to 20 carbon atoms such as phenyl, naphthyl, biphenyl, terphenyl, phenanthryl and anthracenyl, as well as tolyl, isopropylphenyl and t. And alkyl-substituted aryl groups such as -butylphenyl, dimethylphenyl and 2,6-di-t-butylphenyl.

R in the above formula (1) is a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, phenyl, 2,6-di-t-butylphenyl group. Is particularly preferable.

Examples of the alkali metal represented by M in the above formula (1) include lithium, sodium and potassium. Preferred is potassium.

The amount of the organic oxymetal compound used in the anionic polymerization according to the present invention is not necessarily limited, but the organic oxymetal compound may be used in an amount of 0.01 to 10 mol per 100 mol of the total monomers used. It is preferable to use it in a ratio within the range from the viewpoint that the desired acrylic acid ester polymer can be smoothly produced.

The organic aluminum compound used in combination with the organic oxymetal compound of the above formula (1) as the anionic polymerization initiator in the present invention includes trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum,
Alkyl aluminum such as trihexyl aluminum;
Alkyl aluminum chlorides such as dimethyl aluminum chloride, diethyl aluminum chloride, dipropyl aluminum chloride, diisobutyl aluminum chloride, dihexyl aluminum chloride, methyl aluminum dichloride, ethyl aluminum dichloride, propyl aluminum dichloride, isobutyl aluminum dichloride, hexyl aluminum dichloride; dimethyl aluminum hydride Alkyl aluminum hydrides such as diethyl aluminum hydride, dipropyl aluminum hydride, diisobutyl aluminum hydride and dihexyl aluminum hydride; methylbis (2,6-di-t-butylphenoxy) aluminum;
Ethylbis (2,6-di-t-butylphenoxy) aluminum, isobutylbis (2,6-di-t-butyl-
Alkyl aluminum alkoxides such as 4-methylphenoxy) aluminum and the like can be mentioned. Among them, trialkylaluminum and alkylaluminum alkoxide are preferable, and triethylaluminum, tripropylaluminum, triisobutylaluminum and isobutylbis (2,6-di-t) are more preferable.
-Butyl-4-methylphenoxy) aluminum and the like can be mentioned. Organoaluminum compound is part 1
It is possible to use one species or a combination of two or more different species.

Regarding the usage ratio of the organoaluminum compound, a suitable ratio can be selected and adopted depending on the kind of the polymerization method, the kind of the polymerization solvent when carrying out the solution polymerization, various other polymerization conditions and the like. However, it is generally preferable to use the organoaluminum compound in a ratio of 1.0 mol or more, and preferably 2.0 mol or more, relative to 1 mol of the organic oxymetal compound of the formula (1). Is more preferably used. From the viewpoint of polymerization reaction, there is no upper limit to the amount of the organoaluminum compound (I) used,
From the viewpoints of production cost, removal of the organoaluminum compound residue contained in the polymer, and the like, the amount of the organoaluminum compound used may be 500 mol or less with respect to 1 mol of the organic oxymetal compound of the formula (1). Preferably 10
It is more preferable to keep it at 0 mol or less.

The organic oxymetal compound of the above formula (1) and the organic aluminum compound react with each other and add to the acrylic ester to start anionic polymerization. For example, when t-butoxy potassium is used as the organic oxy metal, triisobutyl aluminum is used as the organic aluminum compound, and t-butyl acrylate is used as the acrylic ester, the polymerization proceeds by the reaction of the following chemical formula 1.

[0027]

[Chemical 1]

The anionic polymerization reaction according to the present invention can be carried out without using an organic solvent, but the polymerization temperature can be controlled and the conditions in the polymerization system can be made uniform so that the polymerization proceeds smoothly. From the viewpoint of obtaining, it is preferable to carry out in an organic solvent. At that time, the safety when handling chemicals is relatively high,
A hydrocarbon solvent and / or a halogenated hydrocarbon solvent is preferably used in consideration of the fact that the waste water is less likely to be mixed and the solvent can be easily collected and purified.

Typical examples of the hydrocarbon solvents that can be used are benzene, toluene, xylene, cyclohexane,
Methylcyclohexane and the like can be mentioned, and usable halogenated hydrocarbon solvents include chloroform, methylene chloride, carbon tetrachloride and the like. These organic solvents may be used alone or in combination of two or more. Among these, hydrocarbon solvents are more preferably used. The organic solvent used for the polymerization is preferably purified by degassing and dehydrating in advance.

The amount of the organic solvent used is generally the amount of the acrylic ester used, from the viewpoints of smooth progress of anionic polymerization, ease of separation and acquisition of the produced acrylic ester polymer, burden of waste liquid treatment, and the like. It is preferable to use the organic solvent in a ratio of 200 to 3000 parts by mass, more preferably 300 to 2000 parts by mass, with respect to 100 parts by mass.

The method of adding the organic oxymetal compound, the organoaluminum compound and the acrylic ester to the anionic polymerization system is not particularly limited, and a suitable method can be adopted as required. For example, regarding the organic oxymetal compound and the organic aluminum compound, each may be added to the polymerization system as it is, or one or both of them may be added to the polymerization system in a state of being dissolved in an organic solvent or an acrylic ester. Good. The acrylic ester may be supplied to the polymerization system as it is, or may be supplied to the polymerization system in a state of being dissolved in an organic solvent in advance.

When the anionic polymerization reaction is carried out on an industrial scale, the temperature of the polymerization system can be easily controlled, while the acrylate ester is supplied to the polymerization reaction system itself or in the form of a solution containing it. It may be preferable to carry out a polymerization reaction. At this time, the supply of the acrylate ester may be continuous or intermittent.

Regarding the order of contacting the organic oxymetal compound, the organic aluminum compound and the acrylic ester at the start of the polymerization, generally, the organic oxymetal compound is contacted with the organic aluminum compound and then with the acrylic ester. Polymerization is preferably initiated by contacting the organooxy metal compound with a portion of the organoaluminum compound and then with a mixture of an acrylic ester and the remainder of the organoaluminum compound. .

In the anionic polymerization reaction used in the present invention, various known additives may be added, if desired. Examples thereof include inorganic salts such as lithium chloride; alkoxide compounds such as lithium 2- (2-methoxyethoxy) ethoxide and potassium t-butoxide; organic quaternary salts such as tetraethylammonium chloride and tetraethylphosphonium bromide.

The anionic polymerization reaction used in the present invention is preferably carried out in an atmosphere of an inert gas such as nitrogen, argon or helium. Further, it is preferable to carry out the polymerization under a sufficient stirring condition so that the reaction system becomes uniform.

Regarding the polymerization temperature in the anionic polymerization reaction according to the present invention, suitable conditions are selected and adopted depending on the kind of organic oxymetal compound, the kind of organic aluminum compound, the kind of organic solvent, the kind of acrylate ester, etc. can do. Generally, if a low polymerization temperature is adopted, the polymerization initiation efficiency decreases, the living polymerization property decreases,
Although it is easy to suppress inconveniences such as an increase in molecular weight distribution (increase in non-uniformity of molecular weight), if the polymerization temperature is excessively lowered, it is industrially disadvantageous in that the required amount of cooling utility increases and the polymerization rate decreases. May be From the viewpoint that an acrylic acid ester polymer having a uniform molecular weight (or degree of polymerization) can be industrially advantageously produced in a high yield while maintaining high living polymerizability, it is generally -100 ° C to +.
It is preferable that the temperature is within the range of 60 ° C, and -80 ° C.
More preferably, the temperature is within the range of + 40 ° C.

The reaction time in the anionic polymerization used in the present invention depends on the type of acrylic ester, the type of organic solvent,
Depending on various conditions such as the type of the organic oxymetal compound, the type of the organoaluminum compound, the polymerization temperature, the molecular weight of the target acrylic acid ester polymer, and the monomer concentration in the organic solvent, a suitable time may be appropriately selected. Good. If the polymerization time is too short, the proportion of unreacted monomer will increase, and conversely, if the polymerization time is too long, productivity will decrease. Therefore, the polymerization time is usually within the range of several seconds to 100 hours. Is preferably adopted.

In the present invention, a block copolymer comprising an acrylic acid ester polymer block / methacrylic acid ester polymer block is obtained by anionically polymerizing an acrylic acid ester and then adding and polymerizing a methacrylic acid ester. be able to.

Examples of the methacrylic acid ester used in the method for producing the block copolymer of the present invention include the methacrylic acid esters described above, but when properties such as transparency and availability are required. Has 1 carbon
It is preferable that the carboxy group of methacrylic acid be substituted for the alkyl group of ~ 6, and methyl methacrylate, ethyl methacrylate, and cyclohexyl methacrylate be particularly preferable.

When the block copolymer is produced, the proportion of the acrylic acid ester polymer block is 5 to 95 mol%.
It is preferable that the range is from the viewpoint of exhibiting characteristics such as compatibility and adhesion.

In the production of the block copolymer, the reaction temperature and reaction time after addition of the methacrylic acid ester can be appropriately selected and adopted, but the reaction temperature and reaction time as mentioned above are preferably adopted. To be done.

In the present invention, a polyfunctional acrylic having a functionality of two or more is used after the completion of the anionic polymerization of the acrylic ester or the block copolymer and before the addition of the polymerization terminator. By adding acid ester or methacrylic acid ester to the reaction system, a so-called "star type" or "multi-arm type" polymer can be produced. In the present invention, after completion of all anionic polymerization of the acrylic ester or block copolymer and before the addition of the polymerization terminator,
A terminal functional group-providing agent (eg, aldehyde, lactone, carbon dioxide, etc.) or a small amount of functional group-containing anionic polymerizable monomer (eg, glycidyl methacrylate, etc.) may be added to the reaction system. It is possible to obtain an acrylic acid ester polymer or a block copolymer having a functional group such as a hydroxyl group, a carboxyl group or an epoxy group at the terminal. That is, when polymerization is carried out using a monofunctional anionic polymerization initiator, an acrylate polymer or block copolymer having a functional group at one end of the molecular chain can be obtained, and a bifunctional anion can be obtained. When polymerization is carried out using a polymerization initiator, an acrylate polymer or block copolymer having functional groups at both ends of the molecular chain can be obtained.

When a metal component derived from an organic oxymetal compound or an organoaluminum compound remains in the acrylic ester polymer or block copolymer separated and obtained from the reaction mixture after the termination of the polymerization, the acrylic ester polymer And materials using it (eg adhesives, adhesives, etc.)
May cause deterioration of physical properties (adhesive strength, adhesive strength, etc.) and poor transparency (poor appearance, coloring, etc.). Therefore, depending on the intended use, metal compounds derived from organic oxymetal compounds and organoaluminum compounds may be used. Is preferably removed after the polymerization is completed. As a method for removing the metal compound, the acrylic acid ester polymer or block copolymer is subjected to a cleaning treatment such as an acidic aqueous solution or a cleaning treatment such as an adsorption treatment using an adsorbent such as an ion exchange resin. Is effective. Even after the polymerization is stopped, the organoaluminum compound reacts with moisture in the air and is easily converted into aluminum hydroxide, but since aluminum hydroxide is hardly soluble in both acidic and alkaline aqueous solutions, it is removed once it is formed. Becomes difficult. Therefore, it is preferable to wash the acrylic acid ester polymer or the block copolymer (which may be in the form of the reaction mixture) with an acidic aqueous solution as soon as possible after the completion of the polymerization in terms of high efficiency of removing the metal component. As the acidic aqueous solution, for example, hydrochloric acid, sulfuric acid aqueous solution, nitric acid aqueous solution, acetic acid aqueous solution, propionic acid aqueous solution,
An aqueous solution of citric acid or the like can be used.

The method for separating and obtaining the acrylic ester polymer or the block copolymer from the reaction mixture after the termination of the polymerization is not particularly limited, and any known method can be adopted. it can. For example, a method of pouring the reaction mixture into a poor solvent for the acrylic ester polymer and the block copolymer to precipitate the polymer, a method of distilling the solvent from the reaction mixture to obtain the polymer, and the like can be adopted. .

Further, according to the method of the present invention, an acrylic acid ester polymer having an arbitrary molecular weight can be produced by having a high living property, that is, by suppressing the termination reaction of the anionic polymerization reaction. Although the molecular weight of the acrylic acid ester polymer that can be produced is in a wide range, it is generally that the number average molecular weight is in the range of 1,000 to 1,000,000, that is, handleability, fluidity, and flowability of the acrylic acid ester polymer.
It is preferable in terms of compatibility with other polymers (for example, acrylic resin, vinyl chloride resin, fluorine resin, etc.), coatability, adhesiveness, and tackiness. Moreover, according to the method of the present invention, an acrylic acid ester polymer having a high molecular weight uniformity (that is, a narrow molecular weight distribution) is usually obtained, and the molecular weight distribution (Mw / Mn) thereof is often 1.5. It is the following.

The acrylic ester polymer or block copolymer obtained by the method of the present invention can be used as an adhesive or tackifier by utilizing its excellent transparency, chemical resistance, weather resistance, flexibility and handleability. Agent, paint, foam, cushioning material, damping material,
It is useful as a raw material and an additive for various products such as a vibration-proof material, a sealing material, and a sealing material. In addition, the acrylic ester polymer or block copolymer obtained by the method of the present invention is used for other thermoplastic resins, thermosetting resins and the like used in various molded articles in the electric / electronic field, automobile field, medical field and the like. It is also possible to improve its impact resistance, paintability, printability, weather resistance, etc. Further, it can be used as a compatibilizing agent between a plurality of resins. The acrylic ester polymer or block copolymer obtained by the method of the present invention is derived from the uniformity of the molecular weight distribution and can exhibit excellent mechanical properties when formed into a molded article. When it is added to, excellent moldability can be exhibited. When the acrylic ester polymer or block copolymer obtained by the method of the present invention has a functional group at one end or both ends of its main chain, the polymer is a polymer of polyester, polyurethane, polyamide, polyimide or the like. It can also be used as a raw material component. When the acrylic ester polymer or block copolymer obtained by the method of the present invention has a polymerizable vinyl group at one end or both ends of its main chain, the polymer is used as a macromonomer or a crosslinking agent. It is possible.

When the acrylic acid ester polymer or block copolymer obtained by the method of the present invention is used for various purposes, the polymer is added to a deterioration inhibitor such as an antioxidant or an ultraviolet absorber, a plasticizer. Resins or oligomers such as stabilizers, thickeners and tackifying resins, colorants, pigments and extenders may be added.

[0048]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

The number average molecular weights and molecular weight distributions (Mw / Mn) of the polymers obtained in the examples are based on polymethyl methacrylate as a standard GPC (manufactured by JASCO; Jasco-Bowin).
System (ver. 1.50)). The composition of the polymer was determined by ¹ H-NMR (Brucker, Avance 400).

(Example 1) Argon-substituted 100 ml
23.8 mg of potassium t-butoxide in Schlenk
(0.212 mmol) and 15 ml of toluene were added, 1.05 ml (1.02 mmol) of a 0.97 M hexane solution of triisobutylaluminum was added, and the mixture was stirred at 0 ° C. for 30 minutes. After stirring, 3.1 ml (21.2 mmol) of t-butyl acrylate was added, and polymerization was performed by stirring at 0 ° C. for 1 hour.

Then, the solvent was distilled off under reduced pressure, the residue was dissolved in 200 ml of chloroform, and once with 100 ml of 1N hydrochloric acid, water 2 times was added.
It was washed twice with 00 ml. Chloroform was distilled off and the residue was dried under reduced pressure to obtain 2.71 g of a polymer (yield 100%). The number average molecular weight of the obtained polymer was 47700, and the molecular weight distribution was 1.06.

Example 2 In Example 1, the amount of t-butyl acrylate added was 6.2 ml (42.4 mmol).
By the same procedure as in Example 1 except that the polymerization time was 3 hours, 5.42 g of a polymer was obtained (yield 100%). The number average molecular weight of the obtained polymer is 2
The molecular weight distribution was 19000.

(Example 3) Instead of the triisobutylaluminum 0.97M hexane solution in Example 1, triethylaluminum 0.97M hexane solution was used.
2.72 g of a polymer was obtained by polymerizing in the same manner as in Example 1 except that 1.47 ml (1.43 mmol) was used and the polymerization time was 2 hours.
%). The number average molecular weight of the obtained polymer was 306,000,
The molecular weight distribution was 1.25.

Example 4 Argon-substituted 100 ml
23.8 mg of potassium t-butoxide in Schlenk
(0.212 mmol) and 15 ml of toluene were added, 1.05 ml (1.02 mmol) of a 0.97 M hexane solution of triisobutylaluminum was added, and the mixture was stirred at 0 ° C. for 30 minutes. After stirring, 1.58 ml (10.81 mmol) of t-butyl acrylate was added, and 0
Polymerization was performed by stirring at 20 ° C. for 20 minutes. After sampling a part of the reaction solution containing the polymer of t-butyl acrylate, 6.9% of methyl methacrylate was added to the reaction solution.
Polymerization was carried out by adding ml (64 mmol) and stirring at 0 ° C. for 1 hour.

Then, the solvent was distilled off under reduced pressure, the residue was dissolved in 200 ml of chloroform, and once with 100 ml of 1N hydrochloric acid, water 2 times was added.
It was washed twice with 00 ml. Chloroform was distilled off, and the residue was dried under reduced pressure to obtain 8.78 g of a polymer (A) (yield 96%).

Acrylic acid t obtained by sampling
The number average molecular weight of the -butyl polymer was 18,700, and the molecular weight distribution was 1.15. The number average molecular weight of the polymer (A) is 108,000, and the molecular weight distribution is 1.05.
It was confirmed that there was a shift to the higher molecular weight side while maintaining the monomodality. In addition, the composition of the polymer (A) was analyzed by ¹ H NMR.
When analyzed by, it was t-butyl acrylate: methyl methacrylate = 13: 87 (molar ratio). From the above results, it was confirmed that the polymer (A) was a block copolymer of t-butyl acrylate and methyl methacrylate.

Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that triisobutylaluminum was not added.
The yield was as high as 100%, but the number average molecular weight was 2600.
0, the molecular weight distribution was 1.66, and the living property was low.

The above results are summarized in Table 1.

[0059]

[Table 1]

[0060]

According to the present invention, at a relatively high polymerization temperature,
An acrylic ester polymer can be efficiently produced with a high polymerization rate and a high living property.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J015 DA05 DA12                 4J026 HA12 HA25 HA26 HA32 HA39                       HB12 HB25 HB32 HB39 HB45                       HE01

Claims (5)

[Claims] 1. A method for producing an acrylic acid ester polymer by anionically polymerizing an acrylic acid ester as a monomer using an anionic polymerization initiator, wherein the anionic polymerization initiator is represented by the formula (1): R- OM
(In the formula (1), M is an alkali metal, and R is a chain hydrocarbon group or a cyclic hydrocarbon group.) And an organoaluminum compound are used in combination. A method for producing an acrylic acid ester polymer, comprising: 2. The production method according to claim 1, wherein two or more kinds of the acrylic ester are used as the monomer. 3. The production method according to claim 1, wherein a monomer other than the acrylic acid ester which is copolymerizable with the acrylic acid ester is copolymerized. 4. The production method according to claim 1, wherein M in the formula (1) is potassium. 5. A method for producing a block copolymer, which comprises polymerizing an acrylic acid ester by the production method according to claim 1 and then adding and polymerizing a methacrylic acid ester.