JP2002293850A - Block copolymer and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a block copolymer by electron- transferring radical polymerization, which is specific in forming the second block chain obtained from a mathacrylate-based monomer onto the first block chain obtained from an acrylate-based monomer and giving a narrow molecular weight distribution of the product. SOLUTION: The first block chain is obtained by polymerizing an acrylate- based monomer, then the second block chain is obtained by polymerizing a radically polymerizable monomer containing at least one methacrylate-based monomer in the presence of a specific polymerization initiator and a redox catalyst, by regulating law-valence metal (M)<n> (n is an integer) and high-valence metal (M)<n+1> which are contained in the redox catalyst, to a specified range of their molar ratio (M)<n> /(M)<n+1> at starting of the polymerization for obtaining the second chain block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a block copolymer and a method for producing the same, and more particularly, to a novel block copolymer obtained by utilizing a living radical polymerization method and a method for producing the same.

[0002]

2. Description of the Related Art Conventional living radical polymerization methods include the following three methods.
Two methods are being studied.

(1) First, a growing radical is generated from a radical initiator or a covalent chemical species. Next, a pseudo-termination reaction in which the growing radical and the capture radical react while taking in the monomer to form a covalent chemical species, and a reaction in which the capture radical dissociates from the covalent chemical species to generate a growth radical again, are reversible. And the polymerization proceeds.

(2) First, a metal species in a low valence state oxidatively extracts an atom from a covalent bond species to generate a growing radical and a metal species in a high valence state. Next, a pseudo-termination reaction in which the growing radical and the high-valent metal species react while taking in the monomer to generate a low-valent metal species, and a high-valent metal species from the low-valent metal species The reaction of dissociation of the metal species in the state and the generation of a growing radical again occurs reversibly, and the polymerization proceeds.

(3) First, a growing radical is generated from a radical initiator. Next, a pseudo-termination reaction in which the growing radical and the chain transfer agent react while taking in the monomer to generate a chain transfer radical, a reaction in which the chain transfer radical reacts with the chain transfer species to transfer the radical, and a chain transfer reaction Three reactions including a pseudo-termination reaction in which a radical reacts with a monomer to generate a chain transfer radical again occur at the same time, and the polymerization proceeds.

[0006] Among them, the atom transfer radical polymerization method classified into the second method is represented by the following scheme.

[0007]

Embedded image

In the above, P is a polymer chain, (M) is a transition metal, X is a halogen, Y and L are ligands capable of coordinating with (M), n and n + 1 are valences of the transition metal, The low-valent complex (1) and the high-valent complex (2) constitute a redox conjugated system.

First, a low-valent complex (1) radically abstracts a halogen atom X from a halogen-containing polymerization initiator PX to form a high-valent complex (2) and a carbon-centered radical P. (The rate of this reaction is denoted by Kact). The radical P. reacts with the monomer to form the same kind of intermediate radical P. as shown in the figure (the rate of this reaction is represented by Kpropagation). The reaction between the high-valent complex (2) and the radical P. regenerates the low-valent complex (1) while producing the product PX (the rate of this reaction is expressed as Kdeact). . Then, the low-valent complex (1) further reacts with PX to progress a new reaction. In this reaction, controlling the concentration of the growing radical species P. to a low level is most important in controlling the polymerization.

As a specific example of the above atom transfer radical polymerization method, there is the following report.

(1) Polymerization of styrene using α-chloroethylbenzene as an initiator in the presence of CuCl / bipyridyl complex (J. Wang and K. Matyjaszewski, J. Am.
Chem. Soc. , 117, 5614 (1995)

(2) Polymerization of methyl methacrylate initiated by CCl ₄ in the presence of RuCl ₂ (PPh ₃ ) ₃ and an organoaluminum compound (M. Kato, M. Kamigaito, M. Sawam)
oto, T. Higashimura, Macromolecules, 28, 18
21 (1995))

[0013] Thereafter, the design of ligands, metal species, polymerization initiators and the like has been carried out, and the atom transfer radical polymerization method has been developed for various types of monomers including acrylate monomers.

By the way, when an atom transfer radical polymerization method is applied to the production of a block copolymer, it may be difficult to form a block depending on the type of monomer used.
This is explained by the ease of abstraction of the halogen atom at the end of the initiator and the ease of abstraction of the halogen bound to the terminal of the monomer added next, that is, the difference in kact in the formula (1). In particular, when the first block chain is formed of an acrylate-based monomer, it is difficult to generate (block) the second block chain with the next methacrylate-based monomer because the extraction of halogen from the acrylate terminal is slow.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for producing a block copolymer by an atom transfer radical polymerization method. It is an object of the present invention to provide a method for producing a block copolymer having a narrow molecular weight distribution and a second block chain formed of a methacrylate monomer in one block chain, and a novel block copolymer obtained by the production method. is there.

[0016]

Means for Solving the Problems As a result of intensive studies, the present inventors firstly polymerized an acrylate monomer in the presence of a specific polymerization initiator and a redox catalyst to obtain a first block chain. 1 methacrylate monomer
The second block chain is obtained by polymerizing a radical polymerizable monomer containing at least one species, and the low valent metal (M) ⁿ (where n is an integer) of the redox catalyst at the start of the polymerization of the second block chain is as high as n. If the molar ratio (M) ⁿ / (M) ^{n + 1} to the valence metal (M) ^{n + 1} is adjusted to a specific range, a controlled block polymer can be efficiently obtained, and the above object can be achieved. The knowledge that it can be achieved was obtained.

The present invention has been completed based on the above findings, and a first gist of the present invention is that it comprises an acrylate block chain and a methacrylate block chain, and at least one terminal of the methacrylate block chain is terminated. A block copolymer characterized by being a halogen terminal.

The second gist of the present invention is to provide a block copolymer characterized by comprising at least the following first block chain forming step (i) and second block chain forming step (ii) in order. Lies in the manufacturing method.

<First Block Chain Formation Step (i)> An organic halide or a sulfonyl halide compound containing a bromine atom or an iodine atom is used as a polymerization initiator.
A redox catalyst comprising a metal complex in which at least one transition metal (M) selected from Groups 7 to 11 of the periodic table is a central metal and has at least a halogen atom in a ligand, wherein the halogen atom is a bromine atom Alternatively, the acrylate monomer is polymerized in the presence of a catalyst that is an iodine atom.

<Second block chain forming step (ii)> A metal complex in which at least one transition metal (M) selected from Groups 7 to 11 of the periodic table is the central metal and the ligand contains at least a halogen atom. A halogen atom is a chlorine atom or a fluorine atom, and the low-valent metal (M) ⁿ (where n is an integer) of the redox catalyst at the start of polymerization of the second block chain is as high as In the presence of a redox catalyst in which the molar ratio (M) ⁿ / (M) ^{n + 1 of the} valence metal (M) ^{n + 1} is in the range of 90/10 to 0.1 / 99.9, the methacrylate monomer is prepared. Polymerize.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
First, for convenience of explanation, a method for producing a block copolymer according to the present invention will be described. The atom transfer radical polymerization used in the production method of the present invention is conceptually represented by the above-mentioned scheme (Formula 1).

The production method of the present invention includes a first block chain forming step (i) and a second block chain forming step (ii) sequentially.

<First Block Chain Formation Step (i)> In this step, an organic halide or a sulfonyl halide compound containing a bromine atom or an iodine atom is used as a polymerization initiator. A redox catalyst comprising a metal complex in which at least one selected transition metal (M) is a central metal and has at least a halogen atom in a ligand, wherein the halogen atom is a bromine atom or an iodine atom. Below, an acrylate monomer is polymerized.

(A1) Polymerization solvent: The radical polymerization in the first block chain formation step (i) can be carried out without a solvent or in various solvents. Examples of the polymerization solvent used as needed include water; ethers such as diethyl ether, tetrahydrofuran, diphenyl ether, anisole, and dimethoxybenzene; N, N-dimethylformamide;
Amides such as N, N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, benzonitrile; ester compounds or carbonate compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, ethylene carbonate and propylene carbonate Methanol, ethanol, propanol, isopropanol, n-butyl alcohol, t
Alcohols such as butyl alcohol and isoamyl alcohol; aromatic hydrocarbons such as benzene and toluene; and halogenated hydrocarbons such as chlorobenzene, methylene chloride, chloroform and chlorobenzene. The amount of the polymerization solvent to be used is not particularly limited.
0.1 to 5000 parts by weight, preferably 1 to 2,000 parts by weight, more preferably 10 to 10 parts by weight, per 100 parts by weight.
00 parts by weight.

(A2) Polymerization initiator: The polymerization initiator used in the first block chain formation step (i) is an organic halide or a sulfonyl halide compound containing a bromine atom or an iodine atom. As such a compound, a polymerization starting point (sometimes referred to as a polymerization starting terminal or a starting terminal)
There is no particular limitation as long as the compound has at least one bromine atom or iodine atom, but is usually a compound having one or two bromine atoms or iodine atoms serving as starting points, and has the following general formula (1) ) To (19) are preferred. However, in the general formulas (1) to (19), C ₆ H ₅ is a phenyl group, C ₆ H ₄ is a phenylene group, R ¹
And R ² are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group or an aralkyl group, each having a functional group such as an alcoholic hydroxyl group, an amino group, a carboxyl group, or an alkylthio group on each carbon atom. And may be the same or different. X is chlorine, bromine or iodine, and n is an integer of 0 to 20.

<Polymerization initiator having one starting point> (1) C ₆ H ₅ —CH ₂ X (2) C ₆ H ₅ C (H) (X) CH ₃ (3) C ₆ H ₅ —C ( X) (CH ₃ ) ₂ (4) R ¹ -C (H) (X) -CO ₂ R ² (5) R ¹ -C (CH ₃ ) (X) -CO ₂ R ² (6) R ^1- C (H) (X) -C (O) R 2 (7) R 1 -C (CH 3) (X) -C (O) R 2 (8) R 1 -C 6 H 4 -SO 2 X

[0027] <Two polymerization initiator starting point> (9) o-, m-, p-XCH 2 -C 6 H 4 -CH 2 X (10) o-, m-, p-CH 3 C ( _{H) (X) -C 6 H} 4
-C (H) (X) CH 3 (11) o-, m-, p- (CH 3) 2 C (X) -C 6 H 4 -
_{C (X) (CH 3)} 2 (12) RO 2 C-C (H) (X) - (CH 2) n-C
_{(H) (X) -CO 2} R (13) RO 2 C-C (CH 3) (X) - (CH 2) n -C
_{(CH 3) (X) -CO} 2 R (14) RC (O) -C (H) (X) - (CH 2) n -C
(H) (X) -C ( O) R (15) RC (O) -C (CH 3) (X) - (CH 2) n -
_{C (CH 3) (X)} -C (O) R (16) XCH 2 CO 2 - (CH 2) n -OCOCH 2 X (17) CH 3 C (H) (X) CO 2 - (CH 2) _n- OCO
C (H) (X) CH 3 (18) (CH 3) 2 C (X) CO 2 - (CH 2) n -OCO
C (X) (CH ₃ ) ₂ (19) RC (O) CH (X) ₂

Examples of the polymerization initiator represented by the general formula (1) include phenylmethyl bromide and phenylmethyl iodide. Examples of the polymerization initiator represented by the general formula (2) include:
Examples of the polymerization initiator represented by the general formula (3) such as 1-phenylethyl bromide and 1-phenylethyl iodide include those represented by the general formula (4) such as 1-phenylisopropyl bromide and 1-phenylisopropyl iodide. Examples of the polymerization initiator include 2-bromopropionic acid, 2-iodopropionic acid, 2-bromobutanoic acid, 2-iodobutanoic acid, methyl-2-bromopropionate, and ethyl-
Examples of the polymerization initiator represented by the general formula (5) such as 2-bromopropionate and methyl-2-iodopropionate include 2-bromoisobutanoic acid, 2-iodoisobutanoic acid, and methyl-2-bromoisobutanoate. Butyrate, ethyl-2-
Examples of the initiator represented by the general formula (6) such as bromoisobutyrate, methyl-2-iodoisobutyrate, and ethyl-2-iodoisobutyrate include α-bromoacetophenone and α-bromoacetone. Examples of the initiator represented by the formula (7) include α-bromoisopropylphenyl ketone, and examples of the initiator represented by the general formula (8) include p-
Examples of the initiator represented by the general formula (9) such as toluenesulfonyl bromide include α, α′-dibromoxylene,
Examples of the initiator represented by the general formula (10) such as α, α′-diiodoxylene include bis (1-bromoethyl) benzene, and examples of the initiator represented by the general formula (11) include bis (1- General formula (1) such as bromo-1-ethyl) benzene
Examples of the initiator represented by 2) include dimethyl 2,5-dibromoadipate, dimethyl 2,5-diiodoadipate, diethyl 2,5-dibromoadipate, diethyl 2,5-diiodoadipate, , 6-Dibromo-1,7
-Dimethyl heptane diacid, 2,6-diiodo-1,7-
Examples of the initiator represented by the general formula (13) such as dimethyl heptandioate, diethyl 2,6-dibromo-1,7-heptanedioate, diethyl 2,6-diiodo-1,7-heptanedioate include: 2,6-dibromo-2,6-dimethyl-1,
Examples of the initiator represented by the general formula (14) such as dimethyl 7-heptane diacid include initiators represented by the general formula (15) such as 3,5-dibromo-2,6-heptanedione. Examples of the initiator represented by the general formula (16) such as 3,5-dibromo-3,5-dimethyl-2,6-heptanedione include ethylene glycol bis (2-bromoacetic acid) esters and the like represented by the general formula (17). Examples of the initiator represented by the general formula (18) include ethylene glycol bis (2-bromopropionic acid) esters and the like. Examples of the initiator represented by the general formula (18) include ethylene glycol bis (2-bromoisobutyric acid) esters and the like. Examples of the initiator represented by the formula (19) include α, α
-Dibromoacetophenone and the like. By using such a polymerization initiator, the initiator efficiency in forming the second block is increased.

(C1) Redox catalyst: The redox catalyst used in the first block chain forming step (i) is represented by
A redox catalyst comprising a metal complex in which at least one transition metal (M) selected from Groups 1 to 11 is a central metal and contains at least a halogen atom in a ligand.
The redox catalyst (redox conjugated complex) is composed of a low-valent metal (M) ⁿ and a high-valent metal (M) ^{n + in} which the low-valent metal (M) ⁿ is the central metal, as shown in the above-mentioned scheme (Formula 1). ^The high valence complex (2) in which ¹ is the central metal changes reversibly. Here, n is an integer of 0 or more, and usually n = 0,
1, 2, 3, 4, 5, and 6.

The low-valent metal (M) ⁿ used specifically
Include Cu ⁺ , Ni ⁰ , Ni ⁺ , Ni ²⁺ , Pd ⁰ , Pd
⁺ , Pt ⁰ , Pt ⁺ , Pt ²⁺ , Rh ⁺ , Rh ²⁺ , Rh ³⁺ , C
o ⁺ , Co ²⁺ , Ir ⁰ , Ir ⁺ , Ir ²⁺ , Ir ³⁺ , F
e ²⁺ , Ru ²⁺ , Ru ³⁺ , Ru ⁴⁺ , Ru ⁵⁺ , Os ²⁺ , Os
³⁺ , Re ²⁺ , Re ³⁺ , Re ⁴⁺ , Re ⁶⁺ , Mn ²⁺ , Mn ³⁺
Metals, among which Cu ⁺ , R
u ²⁺ , Fe ²⁺ , and Ni ²⁺ are preferred.

The monovalent copper compounds include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide and the like. The divalent nickel compounds include nickel dichloride, dibromide. Examples of divalent iron compounds such as nickel and nickel diiodide include iron dichloride, iron dibromide, and iron diiodide. Examples of divalent ruthenium compounds include ruthenium dichloride, ruthenium dibromide, and diiodide. Ruthenium iodide and the like.

The amount of the low valent metal (M) ⁿ is not particularly limited, but is usually 10 ^-4 to 1 as a concentration in the reaction system.
It is 0 ^-1 mol / l, preferably 10 ^-3 to 10 ^-1 mol / l. The amount of the low-valent metal (M) ⁿ is usually 0.01 to 100 mol per 1 mol of the polymerization start terminal of the polymerization initiator.
Mol, preferably 0.1 to 50 mol, more preferably 0.1 to 10 mol.

An organic ligand is used for the above metal complex. Organic ligands are used to enable solubilization in the polymerization solvent and reversible change of the redox conjugated complex. As the coordinating atom to the metal, a nitrogen atom, an oxygen atom,
Examples thereof include a phosphorus atom and a sulfur atom, and a nitrogen atom or a phosphorus atom is preferable. Specific examples of the organic ligand include 2,2′-bipyridyl and derivatives thereof,
-Phenanthroline and its derivatives, tetramethylethylenediamine, pentamethyldiethylenetriamine, tris (dimethylaminoethyl) amine, triphenylphosphine, tributylphosphine and the like.

The transition metal (M) and the organic ligand are
A metal complex may be formed separately in the polymerization system by adding them separately, or a metal complex may be synthesized in advance and added to the polymerization system. In particular, the former method is preferable for copper, and the latter method is preferable for ruthenium, iron, and nickel.

Specific examples of the ruthenium, iron and nickel complexes synthesized in advance include tristriphenylphosphino diruthenium dichloride (RuCl ₂ (PPh ₃ ) ₃ ) and bistriphenylphosphino dichloride (FeCl ₂ (PPh ₃ )
₂ ), bistriphenylphosphino nickel dichloride (N
iCl ₂ (PPh ₃ ) ₂ ) and nickel bistributylphosphino dibromide (NiBr ₂ (PBu ₃ ) ₂ ).

The redox catalyst in the first block chain forming step (i) becomes a corresponding high-valent complex when the above-mentioned complex (low-valent complex) is oxidized. If a low-valent complex in which the halogen atom constituting the metal complex is a bromine atom or an iodine atom is present, a high-valent complex may be present at the start of polymerization, but the mole of the low-valent complex and the high-valent complex may be present. The ratio is not necessarily limited. When the halogen atom constituting the metal complex is not a bromine atom or an iodine atom, Kact shown in the above-mentioned scheme is too small, and the first block chain (·· A ·
・) Is difficult to generate. As the redox catalyst used in this step, a monovalent copper compound is preferable, and copper bromide or copper iodide is particularly preferable.

(D1) Acrylic monomer: The acrylate monomer (A) used in the first block chain forming step (i) includes methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, t-butyl acrylate, Hexyl acrylate, 2-ethylhexyl acrylate, nonyl acrylate, benzyl acrylate, cyclohexyl acrylate, lauryl acrylate, n-octyl acrylate, 2-methoxyethyl acrylate, butoxyethyl acrylate, methoxytetraethylene glycol acrylate, 2-hydroxyethyl acrylate, 2-hydroxy Propyl acrylate, 3-chloro-2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate, Proxy 3-phenoxypropyl acrylate, diethyleneglycol acrylate, polyethylene glycol acrylate, 2- (dimethylamino) ethyl acrylate, N, N- dimethyl acrylamide, N- methylol acrylamide.
One or more of these monomers can be used, and they may be random copolymerized or block copolymerized, and the monomers may be gradually added during the polymerization.

(E1) Other polymerization conditions: The living radical polymerization in the first block chain forming step (i) is usually carried out at -5
The reaction is carried out at a temperature of 0 to 200C, preferably 0 to 150C, more preferably 20 to 130C.

After completion of the polymerization, the first block chain may be separated from the polymerization reaction solution, or the polymerization reaction solution may be directly subjected to the second block chain forming step (ii). When separating the first block chain from the polymerization reaction solution, according to a well-known method,
Evaporation of residual monomers and / or solvent, reprecipitation in a suitable solvent, filtration or centrifugation of the precipitated polymer, washing and drying of the polymer can be performed. If necessary, the polymerization solution is diluted with a good solvent for the produced polymer, for example, tetrahydrofuran (THF), toluene, etc., and passed through a column or pad of alumina, silica or clay to convert the transition metal complex used as a catalyst into a polymerization solvent. Can be removed from In addition, a method of dispersing a metal adsorbent in a polymerization solution for treatment may be employed.

The first block chain (..A ..) obtained in the first block chain forming step (i) is an acrylate polymer, and at least one terminal of the block chain is a bromine terminal or an iodine terminal. is there. When the polymerization initiator used in this step (i) is a monofunctional polymerization initiator, the polymerization proceeds in one direction from the polymerization initiator, and the growth terminal is a bromine terminal or an iodine terminal. There is one terminal or iodine terminal per molecule. On the other hand, when the polymerization initiator used in this step (i) is a bifunctional polymerization initiator, polymerization proceeds in two directions from the polymerization initiator, and the growth terminal is a bromine terminal or an iodine terminal. Has two bromine terminals or two iodine terminals per molecule. Therefore, the first block chain obtained in this step (i) is an acrylate-based polymer, and theoretically one per chain growing terminal is a bromine terminal or an iodine terminal. But,
A side reaction such as a two-molecule termination reaction, a disproportionation reaction, or elimination of bromine or iodine may change the structure of a bromine terminal or an iodine terminal. The terminal group amount of bromine terminal or iodine terminal can be determined, for example, by a proton nuclear magnetic resonance spectrometer ( ¹ H-NM).
It can be calculated from the integral value of adjacent protons using R).

<Second Block Chain Forming Step (ii)> In this step, at least one transition metal (M) selected from Groups 7 to 11 of the periodic table is the central metal and the ligand has at least a halogen atom. Wherein the halogen atom is a chlorine atom or a fluorine atom, and the low-valent metal (M) ^{n of the} redox catalyst at the start of polymerization of the second block chain (where n is integer) high-valence metal (M) ^{n + 1} molar ratio (M) ⁿ /
(M) The methacrylate monomer is polymerized in the presence of a redox catalyst in which ^{n + 1} is in the range of 90/10 to 0.1 / 99.9.

After forming the first block chain (..A ..) in the first block chain formation step (i), the polymer is once isolated, and the isolated polymer is used as a macroinitiator. In this step, the polymerization reaction of the second block chain may be newly started, or after the formation of the first block chain, the methacrylate-based monomer used for the second block chain is subsequently added, and the polymerization is started. The process may start.

(A2) Polymerization solvent: The radical polymerization in the second block chain formation step (ii) is usually preferably performed in a polymerization solvent. When the first block chain forming step (i) is performed without a solvent, or when the polymer is once isolated after forming the first block chain, the polymer obtained in the step (i) is A new solvent may be added. Further, a polymerization solvent may be additionally added to the polymerization reaction solution containing the polymer obtained in the step (i) and the solvent, if necessary.

As the polymerization solvent, a solvent containing at least one selected from the group consisting of water, ethers, amides, nitriles and alcohols is used. As ethers,
Examples include diethyl ether, tetrahydrofuran, diphenyl ether, anisole, dimethoxybenzene, and the like. Examples of the amides include N, N-dimethylformamide (DMF) and N, N-dimethylacetamide. The examples of the nitriles include acetonitrile, Examples of pionitrile, benzonitrile, and alcohols include methanol, ethanol, propanol, isopropanol, n-butyl alcohol, t-butyl alcohol, and isoamyl alcohol. Among these,
At least one member selected from the group consisting of water, ethers, amides and alcohols is preferable, and water, anisole or D
MF is more preferred.

In the second block chain forming step (ii), the above-mentioned polymerization solvent and other solvents, for example, aromatic hydrocarbons such as benzene and toluene, and halogenated hydrocarbons such as chlorobenzene, methylene chloride, chloroform and chlorobenzene. It may be used by mixing with hydrogen or the like. However, in this case, the amount of the above-mentioned polymerization solvent must be equal to or more than the molar amount of the initiator.

The amount of the polymerization solvent used is not particularly limited, but is usually 0.1 to 5,000 parts by weight, preferably 1 to 100 parts by weight, based on the amount of the first block chain and the monomers charged.
2,000 parts by weight, more preferably 10-1000 parts by weight.

(B2) Polymerization initiator: In the second block chain forming step (ii), the first block chain forming step (i)
The first block chain obtained in (1) functions as a polymerization initiator, that is, a macroinitiator. As described above, the first block chain is an acrylate polymer, and at least one terminal of the block chain is a bromine terminal or an iodine terminal. Since the bromine terminal or the iodine terminal becomes the polymerization initiating terminal, the polymerization proceeds in one direction when there is one polymerization initiating terminal in the first block chain, and when the polymerization initiating terminal is two in the first block chain, Polymerization proceeds in two directions.

(C2) Redox catalyst: In the second block chain forming step (ii), at least one transition metal (M) selected from Groups 7 to 11 of the periodic table is the central metal and the ligand is a ligand. A redox catalyst comprising a metal complex containing at least a halogen atom, wherein the halogen atom is a chlorine atom or a fluorine atom, and the low-valent metal (M) ⁿ ( Where n is an integer) and a high-valent metal (M) ^{n + 1}
The molar ratio of (M) n / (M) ^{n + 1} is 90/10 to 0.1 /
A redox catalyst is used that is in the range of 99.9, preferably 60/40 to 1/99.

The redox catalyst (redox conjugated complex) used in the present step (ii) is the same as the redox catalyst used in the first block chain forming step (i), as shown in the above-mentioned scheme (Chem. 1). valent metal (M) ⁿ is a central metal and low valent complex (1) and a high-valence metal (M) high-valence complex n ^{+ 1} is a central metal (2) is reversibly changed. Here, n is an integer of 0 or more, and usually n = 0,
1, 2, 3, 4, 5, and 6.

Specific low-valent metal (M) ^{n used}
Include Cu ⁺ , Ni ⁰ , Ni ⁺ , Ni ²⁺ , Pd ⁰ , Pd
⁺ , Pt ⁰ , Pt ⁺ , Pt ²⁺ , Rh ⁺ , Rh ²⁺ , Rh ³⁺ , C
o ⁺ , Co ²⁺ , Ir ⁰ , Ir ⁺ , Ir ²⁺ , Ir ³⁺ , F
e ²⁺ , Ru ²⁺ , Ru ³⁺ , Ru ⁴⁺ , Ru ⁵⁺ , Os ²⁺ , Os
³⁺ , Re ²⁺ , Re ³⁺ , Re ⁴⁺ , Re ⁶⁺ , Mn ²⁺ , Mn ³⁺
Metals, among which Cu ⁺ , R
u ²⁺ , Fe ²⁺ , and Ni ²⁺ are preferred.

Examples of the monovalent copper compound include cuprous chloride and cuprous fluoride. Examples of the divalent nickel compound include nickel dichloride and nickel difluoride. Examples of the divalent iron compound include divalent iron compound. Examples of divalent ruthenium compounds such as iron chloride and iron difluoride include ruthenium dichloride and ruthenium difluoride, and are preferably monovalent copper compounds, and more preferably copper chloride or copper fluoride. is there.

When the halogen atom constituting the metal complex used for forming the second block chain is not a chlorine atom or a fluorine atom, Kact in (..A ..) (B.)
Is too large, and the utilization efficiency of the first block chain (······) as a polymerization initiator decreases. In other words, the growth reaction of (..A ..) (..B ..), which has already started the reaction, is prioritized. As a result, unblocked (..A ..) remains, and the molecular weight distribution becomes double peaked. In addition, a block copolymer having a narrow molecular weight distribution cannot be obtained.

The redox catalyst is formed by adding a high-valent complex to a low-valent complex. In the present invention, the low-valent metal (M) ⁿ and the high-valent metal (M) ^{n + 1} of the redox catalyst system must have a molar ratio of 90/10 to 0.1 / 99.9. Under such conditions, the polymerization can be controlled without maintaining the redox equilibrium and greatly reducing the polymerization rate. In the present invention, the polymerization proceeds in a living manner, so that a polymer having a narrow molecular weight distribution can be obtained. When the amount of the low-valent metal (M) ⁿ is larger than the above range, it becomes difficult to control the polymerization. The low-valent complex and the high-valent complex of the redox catalyst in the second block chain forming step (ii) are preferably the same halogen species.
The amount of the metal complex used and the organic ligand of the metal complex are the same as those of the redox catalyst in the first block chain forming step (i) described above.

(D2) Methacrylate monomer: second
Examples of the methacrylate monomer (B) used in the block chain forming step (ii) include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, nonyl methacrylate, and benzyl. Methacrylate,
Cyclohexyl methacrylate, lauryl methacrylate, n-octyl methacrylate, 2-methoxyethyl methacrylate, butoxyethyl methacrylate, methoxytetraethylene glycol methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, tetrahydrofur Examples thereof include furyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, diethylene glycol methacrylate, polyethylene glycol methacrylate, and 2- (dimethylamino) ethyl methacrylate. One or more of these monomers can be used, and they may be random copolymerized or block copolymerized, and the monomers may be gradually added during the polymerization.

(E2) Other polymerization conditions: The living radical polymerization in the second block chain formation step (ii) is usually carried out at -5
0 to 200 ° C, preferably 0 to 150 ° C, 10 to 130
Performed at a temperature of ° C.

Following the first block chain forming step (i) and the second block chain forming step (ii), polymerization for the third and subsequent block chains may be further continued. The monomer used to form the third block chain is not particularly limited as long as it is a radical polymerizable monomer, but is usually a styrene-based monomer, an acrylate-based monomer, or a methacrylate-based monomer. Monomers or acrylate monomers are preferred, and styrene monomers are particularly preferred.

After completion of the polymerization, the remaining monomer and / or solvent can be distilled off, reprecipitation in an appropriate solvent, filtration or centrifugation of the precipitated polymer, washing and drying of the polymer can be carried out according to well-known methods. . If necessary, remove the transition metal complex used as a catalyst from the polymerization solvent by diluting the polymerization solution with a good solvent for the resulting polymer, for example, THF, toluene, etc., and passing the solution through an alumina, silica or clay column or pad. I can do it. In addition, a method of dispersing a metal adsorbent in a polymerization solution for treatment may be employed. If necessary, the metal component may remain in the polymer. The obtained polymer is obtained according to a well-known method.
It can be analyzed by size exclusion chromatography, NMR spectrum and the like.

Solvents used for reprecipitation include water; alkanes having 5 to 8 carbon atoms such as pentane, hexane and heptane; cycloalkanes having 5 to 8 carbon atoms such as cyclohexane; and carbon atoms such as methanol, ethanol and isopropanol. And 1 to 6 alcohols. Among them, water, hexane, methanol or a mixture thereof is preferred.

Next, the block copolymer of the present invention will be described. The block copolymer of the present invention is obtained, for example, by the above-described production method of the present invention, and comprises an acrylate-based block chain and a methacrylate-based block chain, and
At least one terminal of the methacrylate block chain is a halogen terminal. The first block chain forming step (1) and the second block chain forming step (i)
The halogen terminal in the case of the block copolymer obtained via only i) is a chlorine terminal or a fluorine terminal.

The block copolymer of the present invention comprises the first
After the block chain forming step (1) and the second block chain forming step (ii), the block is subjected to another polymerization step, polymerization of another monomer is continued with the halogen terminal as a growth starting point, and block copolymerization containing another block chain is performed. They can be combined or subjected to a denaturing step to react a halogen terminal with a compound having a functional group to form a desired block copolymer having another functional group. And the structure of the terminal of a block copolymer changes by such a subsequent process.

The halogen terminal of the block copolymer of the present invention is preferably a chlorine terminal from the viewpoint of good reactivity and progressing polymerization at a reasonable rate when subjected to the other polymerization steps described above.

In the case where the initiator used in the first block chain forming step (1) is a monofunctional initiator, the obtained polymer has a second block chain at one end of the first block chain. Is a diblock copolymer obtained by polymerization, and theoretically has one halogen terminal per molecule. On the other hand, when the initiator used in the first block chain forming step (1) is a bifunctional initiator, the resulting polymer has a second block chain polymerized at both ends of the first block chain. And theoretically, there are two halogen terminals per molecule. However, the structure of the halogen terminal may change due to a side reaction such as a two-molecule termination reaction, disproportionation reaction, or elimination of halogen. The amount of halogen terminal group per growth terminal is usually 0.7 to 1 , Preferably 0.8 to 1. The amount of halogen end groups is, for example,
It can be calculated from the integral value of the adjacent proton using a proton nuclear magnetic resonance spectrometer ( ¹ H-NMR).

The number average molecular weight of the block copolymer of the present invention is usually from 250 to 500,000, preferably from 500 to 500.
250,000 and a molecular weight distribution (weight average molecular weight:
(Mw / number average molecular weight: Mn) is usually 1.8 or less, preferably 1.5 or less.

Since the block polymer of the present invention is produced by a living radical polymerization method, it has a terminal capable of initiating polymerization. Therefore, the polymerization can be freely started and terminated by utilizing the terminal capable of initiating the polymerization.

The block polymer of the present invention is directly
Elastomers, engineering resins, paints, adhesives,
In addition to being used as inks and image forming compositions, as additives such as cement adjusters, dispersants, emulsifiers, surfactants, viscosity modifiers, paper additives, antistatic agents, coating agents, resin adjusters, etc. used. In addition, the block polymer of the present invention can be used as an intermediate of a larger polymer product such as polyurethane as a water treatment chemical, a composite part, a cosmetic, a hair product, an intestinal dilator, a diagnostic agent, and a sustained release composition. It can be used as a pharmaceutical agent.

[0066]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the following examples, molecular weight was measured using gel permeation chromatography (GPC) calibrated with a polystyrene standard sample. Further, the terminal halogen remaining was calculated from the integral values of adjacent protons using proton nuclear magnetic resonance spectrometer ⁽¹ H-NMR).

Production Example 1 (Production of monofunctional macroinitiator) 540.34 g of anisole as a solvent, 393.19 g (3.07 mol) of t-butyl acrylate as a monomer, 5.3117 g of pentamethyldiethylenetriamine as a ligand ( 3.07 × 10 ^-2 mol), and methyl-2-bromopropionate 2.5441 as a polymerization initiator
g (1.52 × 10 ^-2 mol) was charged into a flask, and 15 g
Nitrogen was bubbled for minutes to obtain a mixed solution. Next, 2.2615 g (1.58 × 10 ⁻² mol) of the above mixed solution and cuprous bromide as a catalyst were charged into a flask equipped with a nitrogen-substituted condenser, a nitrogen inlet tube, a stirrer, and a thermometer. Polymerization was performed at 90 ° C. for 120 minutes.

After completion of the polymerization, the copper complex as a catalyst was removed by passing through a column filled with activated alumina. Then, the obtained polymerization solution is methanol 2000
The resulting mixture was re-precipitated by dropping into ml and dried to obtain a t-butyl acrylate polymer (macro initiator A). When the molecular weight of this polymer was measured by gel permeation chromatography calibrated with a polystyrene standard sample, the number average molecular weight was 1,844 and the molecular weight distribution was 1.09.

Example 1 49.53 g of anisole as a solvent and 47.25 g of methyl methacrylate as a monomer (4.728 × 10 ⁻¹⁾
Mol), 1.8469 g (1.07 × 10 ⁻² mol) of pentamethyldiethylenetriamine as a ligand and 4.95 g of macroinitiator A as a polymerization initiator were charged into a flask, and nitrogen was bubbled for 15 minutes to obtain a mixed solution. . Then, 0.2438 g (2.46 × 10 ⁻³ mol) of cuprous chloride as a catalyst was placed in a flask equipped with a condenser purged with nitrogen, a nitrogen inlet tube, a stirrer, and a thermometer.
0.3522 g (2.62 × 10 ⁻³ mol) of cupric chloride was charged and polymerization was carried out at 85 ° C. At any time, the reaction solution was withdrawn from the flask and the molecular weight was measured. As shown in Table 1, the number average molecular weight of the polymer increased with the lapse of polymerization time, and the molecular weight distribution (weight average molecular weight / number average molecular weight) was a narrow distribution of 2.0 or less. The symbol "-" in the column of the second block chain polymer in Table 1 means that no measurement was made (the same applies to the following tables).

[0070]

[Table 1]

Comparative Example 1 In a flask equipped with a condenser purged with nitrogen, a nitrogen inlet tube, a stirrer and a thermometer, 0.1 ml of cuprous bromide was used as a catalyst.
3792 g (2.64 × 10 ⁻³ mol), cupric bromide 0.
6207 g (2.66 × 10 ⁻³ mol) were charged, followed by 47.34 g of anisole and methyl methacrylate 4
8.33 g (4.833 × 10 ^-1 mol), pentamethyldiethylenetriamine 0.9237 g as a ligand
(5.33 × 10 ⁻² mol), a mixed solution of 5.28 g of macroinitiator A as a polymerization initiator was bubbled with nitrogen for 15 minutes, and then charged in the flask and polymerized at 85 ° C. At any time, the reaction solution was withdrawn from the flask and the molecular weight was measured. As shown in Table 2, although the number average molecular weight of the polymer increased with the lapse of polymerization time, the molecular weight distribution (weight average molecular weight / number average molecular weight) was a distribution of 2.0 or more.

[0072]

[Table 2]

Comparative Example 2 A flask equipped with a condenser purged with nitrogen, a nitrogen inlet tube, a stirrer and a thermometer was charged with 0.3 cuprous chloride as a catalyst.
259 g (3.29 × 10 ⁻³ mol), followed by 21.74 g of anisole and 21.68 g of methyl methacrylate
(2.168 × 10 ^-1 mol), 0.5658 g of pentamethyldiethylenetriamine as a ligand (3.26 × 1 ^-1 mol)
0 ^-3 mol), macroinitiator A as a polymerization initiator
After nitrogen gas bubbling for 5.28 g of the mixed solution for 15 minutes,
The flask was charged and polymerization was carried out at 85 ° C. At any time, the reaction solution was withdrawn from the flask and the molecular weight was measured. As shown in Table 3, although the number average molecular weight increased at the beginning of the polymerization (15 minutes), the number average molecular weight was slightly increased even after the polymerization time had elapsed.

[0074]

[Table 3]

Production Example 2 (Production 2 of bifunctional macroinitiator) Anisole 50 ml (49.8 g) as a solvent, 44.7 g (3.49 × 10 ^-1 mol) of normal butyl acrylate, and pentamethyl as a ligand 1.090 g (6.28 × 10 ⁻³ mol) of diethylenetriamine and 1.09 g (3.15 × 10 ⁻³ mol) of dimethyl 2,6-dibromo-1,7-heptandioate as a polymerization initiator were charged into a flask. The mixture was bubbled with nitrogen for 15 minutes to obtain a mixed solution.
Then, the above-mentioned mixed solution and 0.4509 g of cuprous bromide (3.16) as a catalyst were placed in a flask equipped with a condenser purged with nitrogen, a nitrogen inlet tube, a stirrer and a thermometer.
× 10 ^-3 mol) and polymerized at 95 ° C for 90 minutes.

After completion of the polymerization, the copper complex as a catalyst was removed by passing through a column filled with 50 g of activated alumina. The obtained polymerization solution was dropped into 800 ml of a mixed solvent having a water / methanol volume ratio of 1/5 to perform reprecipitation.
After drying, a normal butyl acrylate polymer (macro initiator B) was obtained. When the molecular weight of this polymer was measured by gel permeation chromatography calibrated with a polystyrene standard sample, the number average molecular weight was 8810 and the molecular weight distribution was 1.14.

Example 2 20 ml (20 g) of anisole as a solvent, 18.7 g (1.87 × 10 ^-1 mol) of methyl methacrylate, and pentamethyldiethylenetriamine 282.
6 mg (1.63 × 10 ⁻³ mol) and 3.0 g of macroinitiator B as a polymerization initiator were charged into a flask, and
Nitrogen was bubbled for 5 minutes to obtain a mixed solution. Next, the above-mentioned mixed solution and 67.3 mg (1.02 × 10 ⁻⁴ mol) of cuprous chloride as a catalyst were placed in a flask equipped with a condenser purged with nitrogen, a nitrogen inlet tube, a stirrer, and a thermometer. 91.4 mg (6.81 × 10 ⁻⁴ mol) of cupric was charged and polymerization was carried out at 95 ° C. for 120 minutes.

After completion of the polymerization, the polymerization solution was added to 100 ml of THF.
(88.9 g), and passed through a column filled with 30 g of activated alumina to remove the copper complex as a catalyst.
1 and reprecipitated, and dried to obtain a colorless and transparent triblock copolymer (methyl methacrylate block chain-normal butyl acrylate block chain-methyl methacrylate block chain). The molecular weight and the molecular weight distribution were measured in the same manner as in Production Example 2, and the residual terminal group amount was measured from H-NMR. The number average molecular weight of the obtained triblock copolymer was 1,8210, the molecular weight distribution was 1.21, the halogen of the terminal group was chlorine, and the residual amount of the terminal group was 1.86 (0.93 per growth terminal). )Met.

Comparative Example 3 In Example 2, 67.3 mg of cuprous chloride was used as a catalyst.
(1.02 × 10 ⁻⁴ mol), 91.4 mg of cupric chloride
(6.81 × 10 ⁻⁴ mol), but in the same manner as in Example 2 except that only 67.3 mg (1.02 × 10 ⁻⁴ mol) of cuprous chloride was used as a catalyst. Polymerization operation and analysis operation were performed. The number average molecular weight of the obtained triblock copolymer was 36,766, and the molecular weight distribution was 1.
69, the halogen of the terminal group is chlorine, the residual amount of the terminal group is 1.23 per molecule (0.61 per growth terminal),
Controlling the molecular weight was difficult.

As is clear from the above-described Examples and Comparative Examples, after the step of obtaining the acrylate-based block chain, the low-valent metal (M) ⁿ and the high-valent metal (M) ^{n + 1} of the redox catalyst system are used. The molar ratio (M) ⁿ / (M) ^{n + 1} of 90
By starting the step of obtaining a methacrylate block chain within the range of / 10 to 0.1 / 99.9, a block copolymer having a narrow molecular weight distribution containing an acrylate block chain and a methacrylate block chain can be obtained.

[0081]

According to the present invention described above, there is provided a method for producing a block copolymer by an atom transfer radical polymerization method, wherein a first block chain of an acrylate monomer is replaced with a second block chain of a methacrylate monomer. Are produced, and a novel block copolymer obtained by the production method and a novel block copolymer obtained by the production method having a narrow molecular weight distribution are provided, and the industrial value of the present invention is great.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takeshi Fukuda 251 F-term at 3-1-1 Hadoyama, Uji-shi, Kyoto (reference) 4J015 CA00 4J026 HA11 HA24 HA38 HB11 HB24 HB38 HB45 HE01

Claims (5)

[Claims] 1. A block copolymer comprising an acrylate block chain and a methacrylate block chain, wherein at least one terminal of the methacrylate block chain is a halogen terminal. 2. The block copolymer according to claim 1, wherein the halogen terminal is a chlorine terminal or a fluorine terminal. 3. The block copolymer according to claim 1, wherein the amount of the halogen terminal group is 0.7 to 1 per growth terminal. 4. A method for producing a block copolymer, comprising at least the following first block chain forming step (i) and second block chain forming step (ii) in order. <First block chain forming step (i)> As a polymerization initiator,
Using an organic halide or a sulfonyl halide compound containing a bromine atom or an iodine atom,
A redox catalyst comprising a metal complex in which at least one transition metal (M) selected from Group 11 is a central metal and has at least a halogen atom in a ligand, wherein the halogen atom is a bromine atom or an iodine atom. The acrylate monomer is polymerized in the presence of a catalyst. <Second block chain forming step (ii)> A redox comprising a metal complex in which at least one transition metal (M) selected from Groups 7 to 11 of the periodic table is the central metal and the ligand contains at least a halogen atom. A low-valent metal (M) ⁿ (where n is an integer) and a high-valent metal of the redox catalyst at the start of polymerization of the second block chain, wherein the halogen atom is a chlorine atom or a fluorine atom. (M) ^{n + 1} molar ratio (M) ⁿ / (M) ^{n + 1} is 90/10
The methacrylate monomer is polymerized in the presence of a redox catalyst in the range of 0.1 / 99.9. 5. The low-valent metal (M) ⁿ is Cu ⁺ , R
The production method according to claim 4, wherein the production method is one selected from the group ^consisting of ^{u2 +} , Fe2 ⁺ , and Ni2 ⁺ .