JPH0770264A - Production of block copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer containing non-polar and polar polymer blocks having prescribed micro-structures in high productivity and yield by adding an organic compound containing typical element of the group II or III to the polymerization system before the polymerization of polar monomer. CONSTITUTION:This block copolymer is produced by incorporating (A) a living polymer of a non-polar monomer (preferably 1,3-butadiene or styrene) started its polymerization with an anionic polymerization initiator (e.g. sec-butyllithium) with (B) an organic compound of formula I and formula II [M<1> is a group II typical element; M<2> is a groups III typical element; R<1> and R<5> each is a 1-20C (preferably 1-10C) hydrocarbon group such as an aliphatic or an alicyclic group] (preferably 0.8-5.0mol-equivalent of trialkylaluminum based on 1mol- equivalent of the Li atom in the polymerization initiator) to form the ate complex of formula III on the polymerization active terminal of the polymer and charging (C) a polar monomer (e.g. acrylic acid ester) to the system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a block copolymer, and more specifically, it is possible to obtain a copolymer having a non-polar polymer block and a polar polymer block with a desired microstructure. With high yield, good productivity,
The present invention relates to a method for producing a block copolymer.

[0002]

2. Description of the Related Art A block copolymer having a non-polar polymer block and a polar polymer block has a characteristic peculiar to both blocks and is notable for its application. In order to develop these properties, each polymer block and block copolymer needs to have a desired microstructure, and this molecular structure can be arbitrarily controlled,
An excellent production method for obtaining this block copolymer with high yield and high productivity is demanded.

Such block copolymers are generally
By polymerizing a conjugated diene monomer and / or a vinyl aromatic hydrocarbon monomer using an anionic polymerization initiator,
First, a non-polar polymer block is obtained, and then a polar monomer is polymerized to obtain a polar polymer block.

Conjugated diene monomers typified by 1,3-butadiene and isoprene, vinyl aromatic hydrocarbon monomers typified by styrene, esters such as acrylic acid and methacrylic acid, and typified by N, N-dialkylacrylamide. It is known that any monomer having a polar group (hereinafter referred to as a polar monomer) can undergo anionic polymerization.

However, in the case of production processes by anionic polymerization, which are generally carried out at temperatures above room temperature, the carbanions at the ends of the polymers usually have a rather intense reactivity with polar monomers. Since it reacts not only with the vinyl group of the monomer but also with a polar group such as a carbonyl group (this reaction is referred to as a side reaction for convenience in the text), there is a problem that polymerization is likely to be inhibited. It was In addition, it is difficult to obtain a block copolymer having a desired microstructure, that is, desired physical properties due to the inhibition of polymerization due to side reaction, so that there is a problem from the viewpoint of controlling the microstructure.

Therefore, various improved methods have been developed as a method for obtaining a block copolymer having a non-polar polymer block and a polar polymer block by introducing a polar monomer into a non-polar living polymer and conducting polymerization. ing.

[0007] For example, the polar monomer is charged and polymerized at 0 ° C.
There is the following method at low temperature. In this method, the reactivity of the carbanion with respect to the polar group in the polar monomer can be suppressed to an appropriate degree, so that the polymerization is not hindered and the production of by-products can be reduced. However, in the industrial process of anionic polymerization, which is usually carried out at a temperature higher than room temperature, it is usually 0 ° C.
It is necessary to cool to the following reaction temperature, therefore cooling cost, increase in viscosity of the polymer solution due to cooling,
There are practically unfavorable problems such as a loss of reaction time required for cooling and a decrease in polymerization rate of polar monomers.

Further, a method in which 1,1-diphenylethylenes are added and sufficiently reacted with the active end of the nonpolar polymer, and then a polar monomer is added (for example, D. Freiss,
P. Remppand H. Benoit, Polym. Lett., 2, 217 (1964)). According to this method, the reactivity of the carbanion at the polymer terminal can be appropriately suppressed by converting the carbonyl anion having high steric hindrance. However, 1,1-diphenylethylene which is an essential component is very expensive, and in some cases, the effect cannot be obtained unless it is combined with the above-mentioned low-temperature polymerization method.

Japanese Unexamined Patent Publication No. 1-131221 (Dow Chemical Company) discloses a method of introducing a polar monomer in the presence of a large amount of ethers such as tetrahydrofuran (THF). However, if a large amount of THF or the like is allowed to coexist in the polymerization system of a non-polar monomer containing a conjugated diene,
Since the diene part in the block copolymer contains a remarkably high concentration of 1,2-bond (or 3,4-bond) in the microstructure, the degree of freedom in controlling the microstructure of the polymer is lost, which is not preferable, In addition, if a large amount of THF or the like is added after the polymerization of the monomer, a considerable amount of water and other polymerization-inhibiting impurities are inevitably mixed in the polymerization system, and some nonpolar living polymer terminals are inactivated. The obtained product contains a large amount of a polymer consisting of only non-polar blocks, and it is difficult to control the degree of polymerization of polar monomers, resulting in poor productivity.

[0010]

An object of the present invention is to obtain a block copolymer having a non-polar polymer block and a polar polymer block with a high yield, high productivity and a desired microstructure. Another object of the present invention is to provide an industrially excellent method for producing a block copolymer.

Another object of the present invention is to provide a block copolymer having a narrow molecular weight distribution by selectively carrying out a polymerization reaction of polar monomers at industrially practical temperatures.
It is an object of the present invention to provide a method for producing a block copolymer which can be obtained in high yield and with good productivity without side reaction.

[0012]

A method for producing a block copolymer according to the present invention comprises a non-polar polymer block obtained by polymerization of a non-polar monomer and a polar polymer block obtained by polymerization of a polar monomer using an anionic polymerization initiator. In the method for producing a block copolymer having the formula (1), at least one organic compound containing a typical element of group II or group III is added to the polymerization system before the polymerization of the polar monomer.

In the method for producing the block copolymer, the anionic polymerization initiator may be a polyvalent polymerization initiator.

Further, in the method for producing the block copolymer, the organic compound containing the typical element may be at least one represented by the following general formulas (I) and (II).

General formula (I) M ¹ R ¹ R ² General formula (II) M ² R ³ R ⁴ R ⁵ (In the formula, M ¹ represents a typical element of Group II, M ² represents III
Represents a typical element of the group. R ¹ , R ² , R ³ , R ⁴ and R ⁵
Represents a group selected from aliphatic, alicyclic and aromatic hydrocarbon groups each having 1 to 20 carbon atoms. R ¹ , R ² , R ³ ,
R ⁴ and R ⁵ may be the same or different from each other. The present inventors have formed an ate-complex when organolithium and an organic compound containing a typical element of Group II or Group III (for example, triethylaluminum) are preferably present in a fixed ratio. However, as a result of intensive studies, it has been shown that it has anionic polymerization ability for polar monomers such as methacrylic acid ester and that its polymerization rate is relatively slow. To the living polymer of the non-polar monomer initiated by the initiator, an appropriate amount of the above organic compound is added to form an ate complex at the polymerization active end of the polymer (step A), and then the polar monomer is added ( By carrying out step B), it is possible to carry out all the processes used in the usual anionic polymerization without adding special conditions. Further, since the above organic compound can effectively absorb impurities in the polymerization system that act to inhibit the polymerization reaction, it is possible to obtain a block copolymer more easily and surely than in the past. Heading, completed the present invention.

Here, the ate complex means that an alkyl (aryl) compound having a strong electron acceptor element such as boron, aluminum or zinc easily reacts with an organic alkali metal (sometimes a Grignard reagent) to form these organic compounds. It refers to an organoanion complex compound obtained by coordinate-bonding an alkyl (aryl) anion from an alkali metal or the like. It is considered that this reaction is carried out as in the following formula (A) when R ₃ Al (trialkylaluminum) and R′Li (organolithium) are used, for example.

[0017]

[Chemical 1]

Therefore, in the present invention, a polymer having a polymerization active terminal such as polybutadienyllithium obtained by using a monovalent polymerization initiator is reacted with an organic compound such as R ₃ Al. Thus, the reaction for forming an ate complex is considered to occur as in the following formula (B).

[0019]

[Chemical 2]

Therefore, if a monovalent polymerization initiator is used,
A polymer portion forming an art complex, that is, a non-polar polymer block (P ¹ ) represented by a polybutadiene portion in the general formula (B), and a polar polymer block (P ² ) formed by a polar monomer added thereafter. It is possible to produce a block copolymer having a structure (P ¹ -P ² ) in which are linked. When the polymerization initiator is divalent, a structure (P ² -P ¹ -P ^{2) in} which polar polymer blocks are linked to both ends of a prepolymerized nonpolar polymer block without a special coupling step is provided. ) Is produced, and similarly, a star-type polymer can be produced by using a trivalent or higher polyvalent polymerization initiator. In the present invention, the term "art complex" refers to an art complex containing a non-polar polymer block.

The present invention will be described in more detail below. The anionic polymerization initiator used in the present invention includes well-known organometallic compounds such as organolithium and organosodium, more preferably their alkylated compounds, arylated compounds, aralkylated compounds, alkyltin compounds and amidated compounds, In particular, the metal contained in the organometallic compound is 1
As one or two lithium compounds, that is, as the polymerization initiator, a polymerization initiator containing monovalent or divalent lithium is preferable from the viewpoint of solubility in a solvent and economical efficiency. For example, the polymerization initiator used in the present invention includes methyllithium, ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, t-butyllithium, isobutyllithium, hexyllithium, octyllithium and tetramethylenediamine. Alkyllithium and alkyldilithium typified by lithium, pentamethylenedilithium, hexamethylenedilithium, etc., Aryllithium and aryldilithium typified by phenyllithium, tolyllithium, lithium naphthylide, benzyllithium, diisopropenyl Aralkyllithium and aralkyldilithium typified by dilithium and the like produced by reaction with benzene and butyllithium, alkyltin lithium typified by tributyltin lithium, and hexamethylene Examples thereof include amide lithium represented by imide lithium. In particular, n-butyllithium and sec-butyllithium are preferable as the monovalent initiator, and dilithiation of p-diisopropenylbenzene is preferable as the divalent initiator, from the viewpoints of reactivity and economy.

The amount of the anionic polymerization initiator added is determined depending on the desired molecular weight of the polymer. In general,
The amount is 0.05 to 20 mmol, preferably 0.1 to 10 mmol, relative to 100 g of the monomer. If it exceeds 20 mmol, it becomes difficult to control the polymerization, and if it is less than 0.05 mmol, the polymerization may not proceed due to the influence of impurities, which is not preferable.

The non-polar polymer block in the present invention can be obtained by polymerizing a non-polar monomer.
The non-polar monomer corresponds to a conjugated diene monomer and a vinyl aromatic hydrocarbon monomer, and therefore the non-polar polymer block is a homopolymerization or copolymerization of a conjugated diene monomer, a homopolymerization or copolymerization of a vinyl aromatic hydrocarbon monomer, Alternatively, it is obtained by copolymerization of a conjugated diene monomer and a vinyl aromatic hydrocarbon monomer.

Examples of the conjugated diene monomer usable in the present invention include 1,3-butadiene, isoprene,
1,3-pentadiene, 2,3-dimethylbutadiene,
Examples thereof include 2-phenyl-1,3-butadiene, 1,3-hexadiene and a mixture thereof, and among them, 1,3-butadiene and isoprene are preferable from the viewpoint of industrial economical efficiency. Moreover, as the vinyl aromatic hydrocarbon monomer, styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, 1,1-diphenylethylene,
2,4,6-trimethylstyrene and a mixture thereof may be mentioned. Among them, styrene is preferable from the viewpoint of industrial economy.

The organic compound used in the present invention is
At least one organic compound containing a typical element of group II or group III, which is represented by the following general formulas (I) and (II).

General formula (I) M ¹ R ¹ R ² General formula (II) M ² R ³ R ⁴ R ⁵ (In the formula, M ¹ represents a typical element of Group II, M ² represents III
Represents a typical element of the group. R ¹ , R ² , R ³ , R ⁴ and R ⁵
Represents a group selected from aliphatic, alicyclic and aromatic hydrocarbon groups each having 1 to 20 carbon atoms. R ¹ , R ² , R ³ ,
R ⁴ and R ⁵ may be the same or different from each other. Here, the group II typical element means beryllium, magnesium, calcium, strontium, barium, radium, zinc, cadmium and mercury. Further, the group III typical element means boron, aluminum, gallium, indium, and thallium. Among these elements, boron, aluminum, magnesium and zinc are preferable because of their high effects, and most preferable among these is aluminum, which is industrially easily available.

In the organic compound represented by the general formula (I), R ¹ and R ² are an aliphatic, alicyclic or aromatic group having 1 to 10 carbon atoms from the viewpoint of reaction effect and industrial convenience. A group selected from each hydrocarbon group is preferable, and examples of this organic compound include diethyl magnesium, dipropyl magnesium, dicyclohexyl magnesium, diphenyl magnesium, diethyl zinc, dibutyl zincs, and diphenyl zinc.

In the organic compound represented by the general formula (II), R ³ , R ⁴ and R ⁵ are each an aliphatic or alicyclic group having 1 to 10 carbon atoms from the viewpoint of reaction effect and industrial convenience. A group selected from each aromatic hydrocarbon group is preferable, and examples of this organic compound include triethylaluminum, tripropylaluminum, tributylaluminums, ethyldimethylaluminum, 2-ethylhexylaluminum, isobornylaluminum, cyclohexylaluminum. , Diphenylaluminum, trimethylboron, triethylboron, tributylboron and the like.

The organic compound in the present invention is added to the polymerization system before the polymerization of the polar monomer. That is, the anionic polymerization initiator forms a non-polar polymer block by polymerization of a non-polar monomer, then, after the organic compound is added to the polymerization system, a polar monomer is added to the polymerization system to start polymerization, A polar polymer block is formed. Therefore, the organic compound can be added at any time before the polar monomer is added to the polymerization system to cause the polymerization, that is, in the state where the polar monomer is not present in the polymerization system. Before the end of, especially when the polymerization conversion rate of the non-polar monomer is 90% or more,
Addition is preferable from the viewpoint of efficiency. On the other hand, addition at the initial stage of the polymerization of the nonpolar monomer decreases the polymerization reaction rate of the nonpolar monomer, and therefore the polymerization period of the nonpolar monomer is unnecessarily extended and the efficiency is poor and industrially undesirable. . On the other hand, after the addition of the polar monomer, it becomes difficult to control the reaction mechanism due to the high reactivity of the polar monomer, and the effect of the present invention cannot be obtained.

The above organic compounds may be used alone or in combination of two or more, and the amount of the organic compound added is 0 with respect to 1 molar equivalent of metal atom in the anionic polymerization initiator used. From 0.5 to 10.0 molar equivalents and reactivity and the like, preferably 0.8 to 5.0 molar equivalents. 0.
If it is less than 5 molar equivalents, the desired effect is not obtained. If it exceeds 10.0 molar equivalents, not only the reactivity (polymerization growth) of the block copolymer is remarkably slowed, but also it is generated from the added organic compound at the end of the polymerization. The amount of the residue such as hydroxide to be generated increases, and it becomes necessary to provide a removing step and the like, which causes an increase in cost, which is not preferable.

The polar monomers used in the present invention include acrylic acid esters, methacrylic acid esters, N, N
-Dialkyl acrylamides, vinyl pyridines, maleimides, etc. are mentioned. Regarding acrylic acid esters and methacrylic acid esters, those having 1 to 20 carbon atoms in the alcohol residue of the ester are preferable from the viewpoint of reactivity, and examples thereof include methyl ester, ethyl ester, isopropyl ester, n-butyl ester, sec-butyl ester, t-butyl ester, isobutyl ester (in the present specification, for example, esters containing these four butyl residues are referred to as butyl esters), cyclohexyl ester, 2-ethylhexyl ester, isobornyl ester, adamantyl. Esters, dimethyl adamantyl ester, lauryl ester and the like can be mentioned.
Regarding the N, N-dialkylacrylamides, those having 1 to 10 carbon atoms in the alkyl group are preferable from the viewpoint of reactivity, and N, N-dimethylacrylamide, N, N-diethylacrylamide, N, N-diisopropylacrylamide, etc. Is mentioned. Regarding vinyl pyridines, 2-vinyl pyridine, 4-vinyl pyridine, etc. are preferable from the viewpoint of reactivity. Regarding maleimides, N-
Methylmaleimide, N-ethylmaleimide, N-phenylmaleimide and the like are preferable from the viewpoint of reactivity. Among these, the most preferable are esters of alcohols having large steric hindrance such as secondary alcohols and tertiary alcohols of acrylic acid and methacrylic acid, from the viewpoint of little side reaction, and for example, isopropyl alcohol as an alcohol residue, Examples include sec-butyl alcohol, t-butyl alcohol, isobornyl alcohol, 2-ethylhexyl alcohol, cyclohexyl alcohol and the like. All of the above monomers may be used alone or as a mixture of two or more.

The polar monomer in the present invention is added to the polymerization system after the addition of the organic compound. Further, since the present invention is a method for producing a block copolymer using an anionic polymerization initiator, it is not possible to produce a block copolymer by adding a polar monomer to a polymerization system before a non-polar monomer. Logically, it is not included in the present invention because it cannot form a block copolymer.

The polymerization reaction to form the non-polar polymer block can be carried out at any temperature within the range of about -80 to 150 ° C, with temperatures in the range of -20 to 120 ° C being preferred. Further, the temperature for forming the polar polymer block may be any temperature within the range of about -80 to 120 ° C, but the temperature within the range of -40 to 80 ° C is effective in terms of reaction rate and the like. From the viewpoint of. The polymerization reaction can be carried out under a generated pressure, but it is usually desirable to operate under a pressure sufficient to keep the monomer substantially in a liquid phase. Higher pressures can be employed if desired. Such a pressure can be obtained by a suitable method such as pressurizing the reactor under a gas condition inert to the polymerization reaction.

The production method of the present invention can be carried out by any of the known polymerization methods and is not particularly limited, but carrying out in an inert solvent controls the reactivity and the viscosity of the reaction product. Is preferable because it can be performed easily. Normally, the solvent is preferably a liquid under the conditions of the polymerization reaction, and an aliphatic, alicyclic or aromatic hydrocarbon is used, and a saturated hydrocarbon having 5 to 10 carbon atoms has an influence on the polymerization reaction and industrial convenience. It is preferable from the viewpoint of sex. Solvents that can be used in the present invention include propane, butane, pentane, hexane, heptane, isooctane,
Examples include cyclopentane, cyclohexane, methylcyclohexane, decane, benzene, naphthalene, and tetrahydronaphthalene. These solvents can be used as a mixture of two or more kinds.

The amount of the above-mentioned solvent in the polymerization system is not particularly limited, but it is preferable to prepare it so that the concentration of the final polymer in the solvent is 10 to 40% by weight.

In the present invention, when forming a non-polar polymer block, a randomizer is preferably used depending on the desired molecular structure. The randomizer referred to herein means control of the microstructure of a conjugated diene polymer forming a nonpolar polymer block, for example, 1,2 bonds of a butadiene portion of a butadiene polymer or a butadiene-styrene copolymer, and 3 of an isoprene polymer. , The increase in the number of 4-bonds, and the control of the composition distribution of the monomer units of the conjugated diene-vinyl aromatic hydrocarbon copolymer, such as the randomization of the butadiene units and styrene units of the butadiene-styrene copolymer. It is a compound.
The randomizer of the present invention is not particularly limited, but may include all commonly used ones, for example, those classified into the following groups. (1) Ethers (2) Compounds represented by the following general formula R (OM ¹ ) _n , (RO) ₂ M ² , R (COOM ¹ ) _n , ROCOOM ¹ , RSO ₃ M ¹ , ROSO ₃ M ¹ ( However, R is selected from aliphatic, alicyclic and aromatic hydrocarbon groups, M ¹ is an alkali metal,
In particular, it represents lithium, sodium, potassium, rubidium or cesium, M ² is an alkaline earth metal, specifically calcium or barium, and n is from 1 to 1.
It is an integer of 3. (3) Tertiary Amine The randomizer will be specifically described below.

(1) Examples of ethers include 1,2-
Examples thereof include dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methoxymethyltetrahydrofuran, diethyl ether, triethylene glycol dimethyl ether and the like.

(2) The randomizer represented by the general formula will be described. Specific examples of the alcohol represented by the general formula R (OM ¹ ) _n or (RO) ₂ M ² and the alkali metal salt or alkaline earth metal salt of phenol include methyl alcohol, ethyl alcohol, isopropyl alcohol, tert.
-Butyl alcohol, tert-amyl alcohol, cyclohexyl alcohol, allyl alcohol, 2-butenyl alcohol, benzyl alcohol, phenol, catechol, resorcinol, hydroquinone, 1-naphthyl alcohol, p-nonylphenol, pyrogallol, etc. lithium, sodium, potassium, Rubidium, cesium, calcium and barium salts are included.

The general formula R (COOM ¹ ) _n or ROCOOM
Specific examples of the alkali metal carboxylic acid and acidic carbonic acid ester salt represented by ¹ , are isovaleric acid, lauric acid,
Palmitic acid, stearic acid, oleic acid, rosin acid,
Examples thereof include lithium, sodium, potassium, rubidium and cesium salts such as benzoic acid, pimelic acid, acidic n-dodecyl carbonate and acidic phenyl carbonate.

Specific examples of the alkali metal sulfonic acid and sulfate ester salt represented by the general formula RSO ₃ M ¹ or ROSO ₃ M ¹ include dodecylbenzene sulfonic acid,
Diisopropylnaphthalenesulfonic acid, N-methyl-N
Includes lithium, sodium, potassium, rubidium and cesium salts such as methane sulfonate lauryl amide, sulfate salt of lauryl alcohol, caproyl ethylene glycol sulfate ester.

(3) Examples of tertiary amines include triethylamine and tetramethylethylenediamine.

These randomizers may be used alone or as a mixture of two or more of the same group, and may be of two or more types classified into other groups such as tertiary amines and ethers. You may use together.

Among them, preferable randomizers include the above-mentioned (1) ethers which are particularly easy to control the molecular structure of the block copolymer of the present invention.

The amount of the randomizer used can be freely selected depending on the use of the resulting block copolymer,
Although not particularly limited, it is usually used in the range of 0.01 to 1000 molar equivalents per 1 molar equivalent of the organolithium compound.

Generally, it is preferred to remove water, oxygen, carbon dioxide and other catalyst poisons from all materials involved in the polymerization process such as initiator components, solvents, monomers.

According to the present invention, it is possible to obtain a block copolymer having any desired molecular weight, and the molecular weight of the obtained copolymer depends on the amount of the initiator and the monomers used in the present invention such as polar monomers. It can be easily controlled by the amount and can be freely selected according to the application and is not particularly limited.

The rubber-like polymer produced by the present invention is used as a vulcanizable rubber for producing automobile tires, gaskets, sheets, belts, window frames, footwear, rubber threads, anti-vibration rubber, packings, and various resins. Can be effectively used as a compatibilizing agent when blending the modifier and the polymer. Further, when the block copolymer obtained by using a polyvalent anionic polymerization initiator contains a non-polar polymer block composed of a conjugated diene-based polymer or copolymer having a low glass transition temperature (Tg), the block copolymer is a thermoplastic rubber. As a shoe sole, a floor tile, an adhesive / adhesive composition, various molded articles, and the like.

[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 as long as the gist thereof is not exceeded.

Various measurements were made by the following methods. Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of polymer
The gel permeation chromatography (G
PC, Tosoh HLC-8020, column: Tosoh G
MH-XL (two in series), and the differential refractive index (R
I) was used in terms of polystyrene using monodisperse polystyrene as a standard. The area ratio of high molecular weight components is GPC
It was determined from the area ratio of the high molecular weight component and the low molecular weight component in the measurement curve of.

The polymerization conversion rate of the polar monomer refers to the polymerization conversion rate of the added polar monomer with respect to the polar polymer block. This is the polymerization conversion rate of all the added monomers (Table 2
Of the total polymer in the above), assuming that the yield of the nonpolar polymer obtained in Step A in the production process of the block copolymer of the present invention is 100%, the addition polar monomer is 100%. % Represents the ratio of the actually polymerized polymer value to the expected polymer value when polymerized.

The microstructure of the butadiene moiety in the polymer was determined by the infrared method (D. Morero et al, Chem.e. Ind., 41,758 (1959)).
Sought by. Further, the content of bound styrene in the butadiene-styrene copolymer was determined by a conventional method using ¹ H-NMR spectrum.

The yields of polar polymer block moieties are similar.
Only non-polar polymer block part synthesized by the formula
Yield of is obtained in advance, and based on this, the block polymer
Calculate the increase in yield of
It was calculated as a percentage. Also, ¹Using 1 H-NMR,
The main chain proton and the polar monomer such as ester
In the case of, the α to β proton of the alcohol residue, N, N
-In dimethylacrylamide, the nitrogen atom is bonded
The proton of the methyl group, of the pyridine ring in vinyl pyridine
Polar polymer block calculated from integral ratio with proton
The yield of the black part was determined. Calculated by these two methods
The yields obtained were in good agreement.

The cyclohexane used in this example was deaerated by aeration with nitrogen and then dried with activated alumina. Polar monomers are dried under nitrogen stream,
Distilled one was used. For n-butyllithium and triethylaluminum, hexane solutions obtained from Kanto Chemical Co., Inc. were used as they were. In addition, all the raw materials of Examples and Comparative Examples were used for each Example and Comparative Example after being dehydrated and purified.

The polymerization operation was performed through the following steps A and B. Example 1 Step A Into a glass bottle with a rubber stopper having a volume of 1 liter, cyclohexane as a solvent and butadiene as a non-polar monomer were charged according to the formulation shown in Table 1, then THF was used as a randomizer and further a polymerization initiator was used as a polymerization initiator. n-Butyllithium was added and the mixture was stirred for 4 hours in a constant temperature bath kept at 50 ° C. A part of the obtained polymer was extracted to obtain Mn, Mw / Mn and molecular weight distribution curve (elution curve) of the polymer by a GPC apparatus. As a result, Mn was 1.79 × 10 ⁵ ,
Mw / Mn was 1.08, and the result of the molecular weight distribution curve is shown in FIG. Then, a hexane solution of triethylaluminum in an amount of 2 molar equivalents to Li was added to the living polymer obtained in the above step, and the mixture was stirred at 50 ° C. for 15 minutes.

Step B To the polymerization reaction solution obtained in Step A, 6 g of t-butyl methacrylate as a polar monomer was added, and the mixture was heated to 50 ° C.
Stir for 30 minutes. After injecting about 1 mmol of isopropanol to the obtained polymer, the polymer solution was added to about 500 ml of isopropanol / water (80/20) to isolate the polymer, which was then placed in a vacuum dryer. It was dried to obtain a polymerization product. Weight% by Polymer Yield and ¹ H-N
The integrated ratio by MR showed that the yield of the obtained polymer was high. Table 2 shows the yield of the polymer and each analytical value. In addition, the molecular weight distribution curve of the polymer by the GPC apparatus is shown in FIG.

[Examples 2, 3 and 4] Examples 2, 3 and 4
Was performed in the same manner as in Example 1 except that isobornyl methacrylate, N, N-dimethylacrylamide and 4-vinylpyridine were used instead of t-butyl methacrylate, respectively. The polymerization recipe is shown in Table 1 and the results are shown in Table 2.

Further, regarding Example 3, the molecular weight distribution curve of the polymer by the GPC apparatus in step B is shown in FIG.

Example 5 Styrene and butadiene were used as the non-polar monomers in step A, the addition amount of these and the addition amount of THF were set to the amounts shown in the formulation of Table 1, and the polymerization time was 2.5. The procedure was the same as in Example 1 except that the time was set. The polymerization recipe is shown in Table 1 and the results are shown in Table 2.

Example 6 As a polymerization initiator, instead of n-butyllithium, a dilithiation compound of p-diisopropenylbenzene (RPFoss et al., Macromolecule 10, 28) was used.
Example 1 except that (prepared according to the method of 7,1977) was used.
I went the same way. The polymerization recipe is shown in Table 1 and the results are shown in Table 2.

Comparative Example 1 The procedure of Example 1 was repeated except that triethylaluminum was not used. The polymerization prescription is shown in Table 1 and the results are shown in Table 2, and the molecular weight distribution curve of the polymer by the GPC apparatus is shown in FIG.

Comparative Examples 2 to 3 Comparative Examples 2 and 3 are the same as Example 1 except that N, N-dimethylacrylamide and 4-vinylpyridine were used without using triethylaluminum, respectively. went. The polymerization recipe is shown in Table 1 and the results are shown in Table 2. For Comparative Example 2, the molecular weight distribution curve of the polymer of Step B by the GPC apparatus is shown in FIG.

Comparative Example 4 The polymerization in Step B
The same procedure as in Comparative Example 2 was performed except that the procedure was carried out at 20 ° C. for 1.5 hours. The polymerization prescription is shown in Table 1 and the results are shown in Table 2, and the molecular weight distribution curve of the polymer by the GPC apparatus in step B is shown in FIG.

[0063]

[Table 1]

[0064]

[Table 2]

The block copolymer obtained in this example is not restricted by the kinds of polar monomers and nonpolar monomers, and is rapidly polymerized at various polymerization temperatures of 50 ° C. It was revealed that the polymerization of It can be confirmed from the molecular weight of Example 1 and the molecular weight distribution curve in FIG. 1 that this block copolymer is composed of a non-polar polymer block and a polar polymer block. The molecular weight after step A (1.79 × 10 ⁵ ) was the molecular weight of the non-polar polymer only, and the molecular weight after step B was higher than this molecular weight (1.89 × 10 ⁵ ). . As a result of IR spectrum analysis of the block copolymer purified by the reprecipitation method, the same absorption as the carbonyl group of the methacrylic acid ester monomer (polar monomer) used for the polymerization (1730 cm ^-1 ) was observed. Since the relative absorption intensity of the carbonyl group is almost proportional to the content of the methacrylic acid ester polymer (polar polymer) block in the all block copolymer, this increased molecular weight portion is It was confirmed to be a polar polymer block composed of the polar monomer. The molecular weight distribution (1.11) after step B is
Compared with the molecular weight distribution after completion (1.08; Table 2), there is almost no change, and the living anionic polymerization reaction of the polar monomer occurs at the polymer end of the polymer obtained in step A, so the molecular weight distribution is narrow. It was shown that. This can also be explained from the fact that the molecular weight distribution of a polymer generally obtained by radical polymerization or the like other than anionic polymerization of polar monomers is wide. Also, step B
The peak of the molecular weight distribution curve after completion is a single peak indicating the block copolymer, and no other characteristic peaks indicating the peak of the polar polymer and the peak of the nonpolar polymer are observed. From the above, it became clear that the block copolymer obtained by the method of the present invention is a block copolymer of a non-polar polymer block and a polar polymer block.

Further, the block copolymer of Example 6 using a divalent diisopropenylbenzene dilithiation as a polymerization initiator showed high tensile elasticity and showed a non-polar polymer block (P ¹ ) of step A. triblock polar polymer block (P ²⁾ is connected to both ends (P ² -P
It was confirmed to have a structure of ^1- P ² ).

Further, as shown in FIG. 1 and FIG. 2, the block copolymer of this example has a narrow molecular weight distribution, and as shown in the comparative example, formation of a high molecular weight component other than the main dispersion was produced. Was not recognized. This high molecular weight component is the result of undesired side reactions due to the high reactivity of polar monomers. The absence of the formation of the high molecular weight component in the block copolymer of this example indicates that the side reaction of the polar monomer is suppressed and the reaction is selectively performed at the polymerization active terminal. In addition, as shown in Table 2,
The polymerization conversion rate of polar monomers was also high, and the yield of all polymers was high. Furthermore, since the organic compound itself used for forming the ate complex is highly reactive with water, oxygen and other active substances, the addition of this type of compound also causes the polymerization inhibiting substance to remain in the polymerization system. It is thought that it hardly mixes into. These facts show that the polar monomer added did not interfere with the polymerization of the polar monomer during the formation, and the added polar monomer formed the block copolymer with high efficiency.

On the other hand, the polymers of Comparative Examples had a low polymerization conversion rate of polar monomers, and on top of that, a high content of unfavorable high molecular weight components was present. This indicates that the polymerization of the polar monomer is hindered, the efficiency is poor, the side reaction is difficult to control, and a block copolymer having a narrow molecular weight distribution cannot be obtained.

Therefore, the polymerization reaction of the polar monomer is selectively carried out at the industrially practical temperature, and the block copolymer having a narrow molecular weight distribution is produced in a high yield and with a high productivity without side reaction. I was able to get it.

[0070]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned constitution, it is possible to obtain a block copolymer having a non-polar polymer block and a polar polymer block with a high yield, high productivity and a desired microstructure. It has an excellent effect.

[Brief description of drawings]

1 is a molecular weight distribution curve of a polymer after steps A and B in Example 1 and Comparative Example 1 by a GPC apparatus.

FIG. 2 is a molecular weight distribution curve of a polymer after Step B measured by a GPC apparatus in Example 3 and Comparative Examples 2 and 4.

Claims (12)

[Claims] 1. A method for producing a block copolymer having a non-polar polymer block by polymerization of a non-polar monomer and a polar polymer block by polymerization of a polar monomer using an anionic polymerization initiator, comprising: A method for producing a block copolymer, which comprises adding at least one organic compound containing a group II or group III typical element to a polymerization system before the polymerization. 2. The method for producing a block copolymer according to claim 1, wherein the anionic polymerization initiator is a polyvalent polymerization initiator. 3. The method for producing a block copolymer according to claim 1, wherein the non-polar monomer is a conjugated diene and a vinyl aromatic hydrocarbon. 4. The method for producing a block copolymer according to claim 1, wherein the non-polar monomer is 1,3-butadiene. 5. The method for producing a block copolymer according to claim 1, wherein the non-polar monomer is styrene. 6. The organic compound containing the typical element,
The method for producing a block copolymer according to any one of claims 1 to 5, which is at least one represented by the following general formulas (I) and (II). General formula (I) M ¹ R ¹ R ² General formula (II) M ² R ³ R ⁴ R ⁵ (In the formula, M ¹ represents a typical element of Group II, M ² represents III
Represents a typical element of the group. R ¹ , R ² , R ³ , R ⁴ and R ⁵
Represents a group selected from aliphatic, alicyclic and aromatic hydrocarbon groups each having 1 to 20 carbon atoms. R ¹ , R ² , R ³ ,
R ⁴ and R ⁵ may be the same or different from each other. ) 7. The typical element is selected from magnesium, zinc, boron and aluminum.
A method for producing the block copolymer described. 8. The method for producing a block copolymer according to claim 6, wherein the typical element is aluminum. 9. In the general formula (I), R ¹ , R ² ,
The method for producing a block copolymer according to claim 6, wherein R ³ , R ⁴ and R ⁵ are groups selected from aliphatic, alicyclic and aromatic hydrocarbon groups having 1 to 10 carbon atoms. . 10. The polar monomer is at least one selected from acrylic acid esters, methacrylic acid esters, crotonic acid esters, N, N-dialkylacrylamides, vinylpyridines, and maleimides. 10. The block copolymer according to any one of items 1 to 9. 11. A method for producing a polymer having a non-polar polymer block composed of styrene and butadiene and a polar polymer block composed of a polar monomer by using an anionic organolithium polymerization initiator, wherein the polar A method for producing a block copolymer, which comprises adding trialkylaluminum in an amount of 0.8 to 5.0 molar equivalents to 1 molar equivalent of lithium atoms in the polymerization initiator before adding the monomer. 12. The block copolymer according to claim 1, wherein a randomizer is used when forming the non-polar polymer block.