WO2021182348A1 - Block copolymer production method and block copolymer - Google Patents

Abstract

The present invention relates to a block copolymer production method comprising a step in which an aromatic polysulfone (a) having at least one Cl atom at a terminal is prepared in advance, and a step in which the aromatic polysulfone (a) and a polyoxyalkylene compound (b) having at least one hydroxy group at a terminal are reacted in a solvent, wherein the proportion of the solvent that forms an azeotropic mixture with water relative to the total amount of the solvent used in the reaction is 0-20 mass%.

Description

Manufacturing method of block copolymer and block copolymer

The present invention relates to a method for producing a block copolymer and a block copolymer.
The present application claims priority based on Japanese Patent Application No. 2020-040191 filed in Japan on March 9, 2020, the contents of which are incorporated herein by reference.

Aromatic polysulfone is used for various purposes as a material for molded products because it has excellent heat resistance and chemical resistance. Hydrophilized aromatic polysulfone may be required depending on the application.

Conventionally, block copolymers having aromatic polysulfone as a polymer chain have been produced. Block copolymers containing the aromatic polysulfone block (A) and the polyoxyalkylene block (B) tend to have excellent hydrophilicity.
Patent Document 1 relates to a method for producing a polyaryl ether sulfone-polyalkylene oxide-block copolymer containing polycondensation of a raw material monomer, and describes a method in which the reaction mixture does not contain a substance that forms an azeotropic mixture with water. ..

Special Table 2016-516875A

However, the above method for producing block copolymers has a problem that it is difficult to increase the molecular weight of the obtained block copolymers.

The present invention has been made to solve the above-mentioned problems, and a block copolymer having a high weight average molecular weight value, which contains an aromatic polysulfone block (A) and a polyoxyalkylene block (B), is used. It is an object of the present invention to provide a method for producing a block copolymer that can be easily produced.

As a result of the studies by the present inventors, conventionally, in the polycondensation reaction in the production of aromatic polysulfone, a solvent for forming a co-boiling mixture with water is added for the purpose of removing water that can inhibit the reaction. In the step of reacting the aromatic polysulfone (a) with the polyoxyalkylene compound (b) having at least one hydroxy group at the terminal in a solvent, rather, the amount of the solvent used to form a co-boiling mixture with water is used. We have found that the molecular weight of the obtained block copolymer increases due to the reduction of the above, and have completed the present invention.
That is, the present invention has the following aspects.

<1> A step of preparing in advance an aromatic polysulfone (a) having at least one Cl atom at the terminal, and
It comprises a step of reacting the aromatic polysulfone (a) with a polyoxyalkylene compound (b) having at least one hydroxy group at the terminal in a solvent.
A method for producing a block copolymer in which the ratio of the solvent forming an azeotropic mixture with water to the total amount of the solvent used in the reaction is 0 to 20% by mass.
<2> The method for producing a block copolymer according to <1>, wherein the aromatic polysulfone (a) has a weight average molecular weight of 30,000 or more, which is obtained as an absolute molecular weight by gel permeation chromatography.
<3> The block copolymer contains an aromatic polysulfone block (A) and a polyoxyalkylene block (B).
The method for producing a block copolymer according to <1> or <2>, wherein the block copolymer has a weight average molecular weight of 40,500 to 70,000, which is obtained as an absolute molecular weight by gel permeation chromatography.
<4> A linear triblock copolymer having the above three blocks and the polyoxy in the order of the polyoxyalkylene block (B), the aromatic polysulfone block (A), and the polyoxyalkylene block (B). A linear diblock copolymer having the above two blocks of an alkylene block (B) and the aromatic polysulfone block (A),
The method for producing a block copolymer according to <3>, which comprises at least one of the above.
<5> The method for producing a block copolymer according to <3> or <4>, wherein the aromatic polysulfone block (A) is composed of a polymer chain having a structural unit represented by the following formula (1).

[In equation (1),
R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom.
n1 and n2 are independently integers of 0 to 4, respectively.
When n1 or n2 is 2 or more, plural R ¹ and R ² may be the same or different from each other. ]
<6> The above-mentioned <3> to <5>, wherein the polyoxyalkylene block (B) is composed of a polymer chain having a structural unit represented by the following formula (2-1). Method for manufacturing block copolymers.

<7> A block copolymer containing an aromatic polysulfone block (A) and a polyoxyalkylene block (B).
A block copolymer having a weight average molecular weight of 40,500 to 70,000, which is obtained as an absolute molecular weight by gel permeation chromatography.
<8> ¹ The block copolymer according to <7>, wherein the number average molecular weight of the polyoxyalkylene block (B) calculated by 1 H-NMR is 5000 or less.
<9> A linear triblock copolymer having the above three blocks and the polyoxy in the order of the polyoxyalkylene block (B), the aromatic polysulfone block (A), and the polyoxyalkylene block (B). A linear diblock copolymer having the above two blocks of an alkylene block (B) and the aromatic polysulfone block (A),
The block copolymer according to <7> or <8>, which comprises at least one of the above.
<10> The block copolymer according to any one of <7> to <9>, wherein the aromatic polysulfone block (A) is composed of a polymer chain having a structural unit represented by the following formula (1). ..

[In equation (1),
R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom.
n1 and n2 are independently integers of 0 to 4, respectively.
When n1 or n2 is 2 or more, plural R ¹ and R ² may be the same or different from each other. ]
<11> The above-mentioned <7> to <10>, wherein the polyoxyalkylene block (B) is composed of a polymer chain having a structural unit represented by the following formula (2-1). Block copolymer.

According to the present invention, it is possible to provide a method for producing a block copolymer capable of easily producing a block copolymer having a high weight average molecular weight value, which comprises an aromatic polysulfone block (A) and a polyoxyalkylene block (B).

Hereinafter, the method for producing the block copolymer of the present invention and the embodiment of the block copolymer will be described.

≪Manufacturing method of block copolymer≫
The method for producing a block copolymer of the embodiment includes a step of preparing an aromatic polysulfone (a) having at least one Cl atom at the terminal in advance, the aromatic polysulfone (a), and at least one hydroxy group at the end. The ratio of the solvent forming the azeotropic mixture with water to the total amount of the solvent used in the reaction, which comprises the step of reacting the polyoxyalkylene compound (b) with the solvent in the solvent, is 0 to 20% by mass. ..

The step of preparing the aromatic polysulfone (a) in advance includes obtaining the aromatic polysulfone (a) and simply preparing a commercially available aromatic polysulfone (a).
Alternatively, the method for producing the block copolymer of the embodiment may further include a step of producing the aromatic polysulfone (a) (aromatic polysulfone production step).

The method for producing a block copolymer of the embodiment includes a step of obtaining an aromatic polysulfone (a) having at least one Cl atom at the terminal by a polycondensation reaction.
It may include a step (block copolymer manufacturing step) of reacting the aromatic polysulfone (a) with a polyoxyalkylene compound (b) having at least one hydroxy group at the terminal.

As an example of the aromatic polysulfone (a), for example, by a polycondensation reaction between a compound represented by the following general formula (a1) and a compound represented by the following general formula (a2), the following general formula (a-1) ) Can be obtained.

[In the formula (a1), R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom.
n1 and n2 are independently integers of 0 to 4, respectively.
When n1 or n2 is 2 or more, plural R ¹ and R ² may be the same or different from each other. ]

Examples of the alkyl group having 1 to 10 carbon atoms in R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, and a t-butyl group. Examples thereof include a group, an n-hexyl group, a 2-ethylhexyl group, an n-octyl group, an n-decyl group and the like.
Examples of the aryl group having 6 to 20 carbon atoms in R ¹ and R ² include a phenyl group, an o-trill group, an m-trill group, a p-trill group, a 1-naphthyl group, a 2-naphthyl group and the like. Be done.
Examples of the halogen atom in R ¹ and R ² include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
n1 and n2 are independently integers of 0 to 4, preferably 0 to 2, and more preferably 0 to 1.

Wherein ^{(a2), R 1, R} 2, n1 and n2 represent the same meaning as in the formula (a1). ]

Examples of the aromatic polysulfone (a) obtained by the above polycondensation reaction include compounds represented by the following general formula (a-1). The compound represented by the following general formula (a-1) is suitable as the aromatic polysulfone (a) used as a raw material in the method for producing a block copolymer of the embodiment.

Wherein ^{(a1), R 1, R} 2, n1 and n2 represent the same meaning as in the formula (a1).
-X ¹ and -X ² are independently -OH or -Cl, and at least one of ^{-X 1} and -X ^{2 is -Cl.}
n is an integer greater than or equal to 0. ]

N is the number of repetitions of the structural unit of the aromatic polysulfone (a-1) in the above formula (a-1).

In the reaction between the aromatic polysulfone (a) and the polyoxyalkylene compound (b), examples of the aromatic polysulfone (a) include those described above.

The value of the weight average molecular weight of the aromatic polysulfone (a) used as a raw material may be appropriately determined according to the weight average molecular weight of the produced block copolymer.
From the viewpoint of improving the molecular weight of the produced block copolymer, the weight average molecular weight of the above aromatic polysulfone (a) used as a raw material may be 30,000 or more, 30,000 or more and 70,000 or less. It may be 40,000 or more and 65,000 or less.

In the present specification, the weight average molecular weight (Mw) is the weight average absolute molecular weight measured by gel permeation chromatography (GPC).

Examples of the polyoxyalkylene compound (b) include compounds represented by the following general formula (b-1).

[In equation (b-1),
R ³ represents an alkylene group having 2 to 6 carbon atoms.
m is an integer of 1 or more, R ³ existing in plural numbers may be the same or different from each other. -Y is an alkyl group having 1 to 3 carbon atoms. ]

Examples of the alkylene group having 2 to 6 carbon atoms in R ³ _{include an ethylene group, a trimethylene group, -CH (CH 3} ) CH _2- , tetramethylene group, -CH ₂ CH ₂ CH (CH ₃ )-, and hexamethylene. The basis etc. can be mentioned.

Examples of the alkyl group having 1 to 3 carbon atoms of —Y include a methyl group, an ethyl group, an n-propyl group, an isopropyl group and the like, and a methyl group is preferable.

M is the number of repetitions of the structural unit of the polyoxyalkylene compound (b-1) in the above formula (b-1).

As an example of the reaction between the aromatic polysulfone (a) and the polyoxyalkylene compound (b), a compound represented by the general formula (a-1) and a compound represented by the general formula (b-1) The reaction of, can be exemplified. The reaction can be represented by the following reaction formula. By this reaction, as an example, a block copolymer represented by the general formula (I-1) is obtained.

[In the formula, R ¹ , R ² , R ³ , n1, n2, n, m, X ¹ , X ² and Y have the same meanings as those in the above formulas (a-1) and (b-1). Represents. ]

Aromatic polysulfone (a) may be used alone or in combination of two or more.

As the polyoxyalkylene compound (b), one type may be used alone, or two or more types may be used in combination.

The amount of the polyoxyalkylene compound (b) having at least one hydroxy group at the terminal is 0.4 to 2.0 with respect to 1 mol of the aromatic polysulfone (a) having at least one Cl atom at the end. It is preferably mol, more preferably 0.4 to 1.5 mol, even more preferably 0.5 to 1.2 mol, and particularly preferably 0.5 to 0.9 mol. When the amount is within the above range, the Mw measured by GPC of the obtained block copolymer can be further improved, which is preferable.
Here, as the aromatic polysulfone (a) having at least one Cl atom at the terminal, the compound represented by the general formula (a-1) is preferable. As the polyoxyalkylene compound (b) having at least one hydroxy group at the terminal, the compound represented by the general formula (b-1) is preferable.

In the method for producing the block copolymer of the embodiment, the reaction between the aromatic polysulfone (a) and the polyoxyalkylene compound (b) is carried out using an alkali metal carbonate and / or an alkali metal bicarbonate as a catalyst base. It is preferable that this is done. Further, in the method for producing a block copolymer of the embodiment, it is more preferable that the reaction is carried out in an organic solvent as a solvent, an alkali metal salt of carbonic acid is used as a base, and the reaction is carried out in an organic solvent.

In the reaction of the aromatic polysulfone (a) and the polyoxyalkylene compound (b), water may be produced as a by-product, and for the purpose of removing this water, a solvent "a solvent that forms an azeotropic mixture with water" is used. May be added.

However, in the production method of the present embodiment, in the reaction of the aromatic polysulfone (a) and the polyoxyalkylene compound (b), an azeotropic mixture with water is formed with respect to the total amount of the solvent used in the reaction. The proportion of the solvent used is 0 to 20% by mass, more preferably 0 to 10% by mass, further preferably 0 to 3% by mass, and the solvent used for the reaction is azeotropically heated with water. It is particularly preferred that it contains substantially no solvent to form the mixture.
By reducing the amount of solvent used to form an azeotropic mixture with water in the reaction of aromatic polysulfone (a) and polyoxyalkylene compound (b), the molecular weight of the block copolymer produced can be increased. be.

The boiling point of the solvent forming the azeotropic mixture with water is preferably 250 ° C. or lower, and may be 230 ° C. or lower, or 210 ° C. or lower. The boiling point of the solvent forming the azeotropic mixture with water may be 40 ° C. or higher, 80 ° C. or higher, or 100 ° C. or higher.
As an example of the numerical range of the boiling point of the solvent forming the azeotropic mixture with water, it may be 40 ° C. or higher and 250 ° C. or lower, 80 ° C. or higher and 230 ° C. or lower, and 100 ° C. or higher and 210 ° C. It may be as follows.

Examples of the solvent for forming an azeotropic mixture with water having a boiling point of 250 ° C. or lower include benzene, chlorobenzene, toluene, xylene, ethylbenzene, methyl isobutyl ketone, hexane, cyclohexane and the like.

The above-mentioned alkali metal salt of carbonic acid may be an alkali carbonate (alkali metal carbonate) which is a positive salt, or a bicarbonate alkali (hydrogen carbonate alkali, alkali metal hydrogen carbonate) which is an acidic salt. It may be a mixture of these (alkali carbonate and alkali bicarbonate). Examples of preferable alkali carbonate include sodium carbonate, potassium carbonate and the like. Examples of preferable alkali bicarbonate include sodium bicarbonate (sodium hydrogen carbonate), potassium bicarbonate (potassium hydrogen carbonate) and the like.

The blending ratio of the alkali metal salt of carbonic acid is preferably 0.90 mol or more and 1.30 mol or less as the alkali metal with respect to 1 mol of the polyoxyalkylene compound (b), and 0.95 mol or more and 1 mol. More preferably, it is 20 mol or less.

Examples of the organic solvent include an aprotic polar solvent, and the boiling point of the aprotic polar solvent under 1 atm is preferably 250 ° C. or lower. By using an aprotic polar solvent having a boiling point of 250 ° C. or lower, the reaction can proceed while refluxing the aprotic polar solvent at a relatively low temperature to remove by-products.

The boiling point of the aprotic polar solvent is preferably 250 ° C. or lower, and may be 230 ° C. or lower, or 210 ° C. or lower. The boiling point of the aprotic polar solvent may be 120 ° C. or higher, 140 ° C. or higher, or 150 ° C. or higher.
As an example of the numerical range of the boiling point of the above-mentioned aprotic polar solvent, it may be 120 ° C. or higher and 230 ° C. or lower, 140 ° C. or higher and 210 ° C. or lower, or 150 ° C. or higher and 210 ° C. or lower. May be good.

Examples of the aprotonic polar solvent having a boiling point of 250 ° C. or lower include sulfonic solvents such as dimethylsulfone and diethylsulfone, N, N-dimethylacetamide, N-methyl-pyrrolidone, N-ethyl-pyrrolidone, N-methylcaprolactam, N, Amide solvents such as N-dimethylformamide, N, N-diethylformamide, N, N-diethylacetamide, N-methylpropionamide, dimethylimidazolidinone, lactone solvents such as γ-butyllactone and β-butyllactone, Examples thereof include sulfoxide-based solvents such as methyl sulfoxide and methylphenyl sulfoxide, cellosolve-based solvents such as tetramethylphosphoric amide and hexamethylphosphoric amide, and cellosolve-based solvents such as ethyl cellosolve acetate and methyl cellosolve acetate.

The reaction between the aromatic polysulfone (a) and the polyoxyalkylene compound (b) is preferably carried out at 250 ° C. or lower. By carrying out the reaction at a relatively low temperature of 250 ° C. or lower, the energy load can be kept low. The reaction temperature is preferably 250 ° C. or lower, may be 230 ° C. or lower, or may be 210 ° C. or lower. The lower limit of the reaction temperature is not limited, but may be 100 ° C. or higher, 120 ° C. or higher, or 140 ° C. or higher.
As an example of the numerical range of the reaction temperature between the aromatic polysulfone (a) and the polyoxyalkylene compound (b), the temperature may be 100 ° C. or higher and 250 ° C. or lower, or 120 ° C. or higher and 230 ° C. or lower. It may be 140 ° C. or higher and 210 ° C. or lower.

Next, from the reaction mixture obtained by the reaction of the aromatic polysulfone (a) and the polyoxyalkylene compound (b), unreacted bases and by-products (halogen when an alkali metal salt is used as the base). Alkali chemicals) and organic solvents can be removed by filtration, extraction, centrifugation, etc. to separate the block copolymer from the reaction mixture.

The organic solvent may be removed by distilling off the organic solvent directly from the solution, or the solution may be mixed with a poor solvent of the block copolymer to precipitate the block copolymer, which may be filtered or centrifuged. It may be done by separating. A predetermined amount of the organic solvent may remain.

Examples of poor solvents for block copolymers include methanol, ethanol, 2-propanol, acetone, hexane, heptane and water, with preference given to water and methanol due to their low cost.
In the present embodiment, one type of poor solvent for the block copolymer may be used alone, or two or more types may be used in combination.

The block copolymer obtained by the method for producing a block copolymer of the embodiment may be exemplified as the block copolymer of the embodiment in the following << block copolymer >>.

≪Block Copolymer≫
The block copolymer of the embodiment contains an aromatic polysulfone block (A) and a polyoxyalkylene block (B), and the weight average molecular weight of the block copolymer is 40,500 to 70,000.

The aromatic polysulfone block (A) has a _{structural unit containing at least a structure in which a sulfonyl group (-SO 2-} ), an arylene group (-Ar-), and an ether bond (-O-) are bonded in this order. Examples thereof include those composed of polymer chains.

The aromatic polysulfone block (A) preferably has a structural unit represented by the following general formula (1) from the viewpoint of heat resistance and chemical resistance.

[In the formula (1), R ¹ , R ² , n1 and n2 have the same meanings as those in the above formula (a1). ]

For example, the structural unit represented by the general formula (1) is contained in an amount of 80 mol% or more and 100 mol% or less with respect to a total amount of 100 mol% of all the structural units constituting the aromatic polysulfone block (A). It may be contained in an amount of 90 mol% or more and 100 mol% or less, or may be contained in a content of 98 mol% or more and 100 mol% or less.

Examples of the polyoxyalkylene block (B) include those composed of a polymer chain having an oxyalkylene group as a structural unit. The polyoxyalkylene block (B) preferably has a structural unit represented by the following formula (2).

[In the formula (2), R ³ has the same meaning as that in the above formula (b-1). ]

Of the above examples, the polyoxyalkylene block (B) preferably has a structural unit represented by the following formula (2-1).

For example, the structural unit represented by the above general formula (2-1) is 80 mol% or more and 100 mol% or less with respect to the total amount of 100 mol% of all the structural units constituting the polyoxyalkylene block (B). It may be contained, may be contained in 90 mol% or more and 100 mol% or less, and may be contained in 98 mol% or more and 100 mol% or less.

The ratio of the aromatic polysulfone block (A) and the polyoxyalkylene block (B) to the whole block copolymer of the embodiment may be 80% by mass or more and 100% by mass or less, and 90% by mass or more and 100% or more. It may be 98% by mass or less, and may be 98% by mass or more and 100% by mass or less.

The weight average molecular weight (Mw) of the block copolymers of the embodiments is 40,500 to 70,000, may be 42,000 to 60,000, may be 43,000 to 55,000, and may be 44,000 to 50,000.
According to the block copolymer of the embodiment, it is possible to provide a block copolymer containing an aromatic polysulfone block (A) and a polyoxyalkylene block (B), which has a significantly increased molecular weight as compared with the conventional one.

The block copolymer of the embodiment contains a polymer that does not contain the aromatic polysulfone block (A) and the polyoxyalkylene block (B) due to unintended decomposition or residual unreacted raw materials. It is also assumed that a very small amount is mixed. In such a case, the weight average molecular weight (Mw) of the block copolymer may be the weight average molecular weight (Mw) of the resin composition containing the block copolymer of the embodiment. The resin composition contains 95% by mass or more and 100% by mass or less of a block copolymer containing the aromatic polysulfone block (A) and the polyoxyalkylene block (B) with respect to the total mass of the resin composition. It may be contained in an amount of 98% by mass or more and 100% by mass or less.

The block copolymers of the embodiment are a linear triblock copolymer having the above three blocks in the order of polyoxyalkylene block (B), aromatic polysulfone block (A), and polyoxyalkylene block (B), and polyoxy. It may contain at least one of a linear diblock copolymer having the above two blocks of an alkylene block (B) and an aromatic polysulfone block (A).

The block copolymers of the embodiment are a linear triblock copolymer having the above three blocks in the order of polyoxyalkylene block (B), aromatic polysulfone block (A), and polyoxyalkylene block (B), and polyoxy. It may contain at least one block copolymer selected from the group consisting of a linear diblock copolymer having the above two blocks of an alkylene block (B) and an aromatic polysulfone block (A).

The linearity referred to here may mean that the block copolymer does not have a branched structure (branched chain). As the linear triblock copolymer, for example, the end of the main chain of the polymer chain of the aromatic polysulfone block (A) and the end of the main chain of the polymer chain of the polyoxyalkylene block (B) are directly linked to each other. Examples include combined ones.

As an example of a linear triblock copolymer having the above three blocks in the order of polyoxyalkylene block (B), aromatic polysulfone block (A), and polyoxyalkylene block (B), the following general formula (I) is used. What is represented can be exemplified.

[In formula (I),
R ¹ , R ² , R ³ , n1 and n2 have the same meanings as those in the above equations (1) and (2).
n is an integer of 0 or more, m is an integer of 1 or more, R ³ existing in plural numbers may be the same or different from each other, the m there are a plurality, it may be the same or different from each other. ]

n is the number of repetitions of the structural unit of the aromatic polysulfone block (A) in the formula (I).
m is the number of repetitions of the structural unit of the polyoxyalkylene block (B) in the formula (I).

In the block copolymer of the embodiment, the ratio represented by the number average molecular weight of the polyoxyalkylene block (B) and the number average molecular weight of the aromatic polysulfone block (A) calculated by ^{1 H-NMR is 0.005.} It may be ~ 0.030, 0.010 to 0.025, or 0.015 to 0.020.
When the value of the above ratio is not more than the above lower limit value, the hydrophilicity of the block copolymer becomes good, which is preferable. If the hydrophilicity of the block copolymer is good, it also contributes to the improvement of the water permeability of the porous membrane obtained by molding the block copolymer. When the value of the above ratio is not more than the above upper limit value, the thermal properties and mechanical properties of the block copolymer are improved, which is preferable.

The number average molecular weight of the aromatic polysulfone block (A) (Mn of the block (A)) may be, for example, 20,000 to 60,000, 25,000 to 50,000, or 27,000 to 40,000. It may be 30,000 to 36,000.

The number average molecular weight of the polyoxyalkylene block (B) (Mn of the block (B)) may be, for example, 5000 or less, 300 to 5000, 300 to 3000, or 300 to 900. It may be 400 to 700, 450 to 600, or 500 to 550.

The block copolymers of the embodiments are among those exemplified above.
The number average molecular weight of the aromatic polysulfone block (A) may be 20000 to 60,000, the number average molecular weight of the polyoxyalkylene block (B) may be 300 to 900, and the number average molecular weight of the aromatic polysulfone block (A). 25,000 to 50,000, the number average molecular weight of the polyoxyalkylene block (B) may be 400 to 700, the number average molecular weight of the aromatic polysulfone block (A) is 27,000 to 40,000, and the polyoxyalkylene block. The number average molecular weight of (B) may be 450 to 600, the number average molecular weight of the aromatic polysulfone block (A) is 30,000 to 36,000, and the number average molecular weight of the polyoxyalkylene block (B) is 500 to 550. May be. By setting the number average molecular weights of the aromatic polysulfone block (A) and the polyoxyalkylene block (B) within the above numerical range, the balance between hydrophilicity, thermal properties and mechanical properties is excellent. Block copolymers are easily obtained.

The number average molecular weight of the polyoxyalkylene block (B) (Mn of the block) and the number average molecular weight of the aromatic polysulfone block (A) (Mn of the block) can be specified by the NMR method and obtained by 1 H-NMR measurement of ^{solution 1.} The NMR-converted number average molecular weight calculated based on the obtained spectrum can be adopted.

The Mn of the polyoxyalkylene block (B) ^{corresponds to the peak intensity I PAO-Main} corresponding to the main chain of the polyoxyalkylene and the binding site of the polyoxyalkylene bound to the aromatic polysulfone _{as the NMR-equivalent molecular weight M n} ^PAO. The number of repeating units of polyoxyalkylene calculated from the ratio of peak intensity I ^{PAO-Link (I PAO-Main} / I ^{PAO-Link ) n PAO} can be calculated from the value obtained by multiplying the molecular weight per repeating unit of polyoxyalkylene. ..

The Mn of the aromatic polysulfone block (A) corresponds to the peak intensity I ^PES-Main corresponding to the main chain of the aromatic polysulfone and the binding site of the aromatic polysulfone bonded to polyoxyalkylene _{as the NMR-equivalent molecular weight M n} ^PES. The number of repeating units of aromatic polysulfone calculated from the ratio of peak intensity I ^{PES-Link (IPES-Main} / I ^{PES-Link ) n PES} can be calculated from the value obtained by multiplying the molecular weight per repeating unit of aromatic polysulfone. ..

^{Solution 1} for calculating the NMR-equivalent molecular weight For 1 H-NMR measurement, a sample dissolved in deuterated dimethylsulfoxide so that the concentration of the block copolymer to be measured is 50 mg / ml can be used, and the measurement can be performed under the following conditions.

Measuring device: PS400WB (manufactured by Varian)
Static magnetic field strength: 9.4 Tesla (resonance frequency: 400 MHz ( ¹ H))
Spinning: 16Hz
Repeat time: 1.5s
Number of integrations: 128 times Temperature: 40 ° C
Chemical shift reference material: Tetramethylsilane

The block copolymer of the embodiment has moderate hydrophilicity and excellent mechanical properties.
As an index of the hydrophilicity of the block copolymer, for example, the value of the water permeability of the porous membrane obtained by molding the block copolymer can be adopted.

The following values of tensile strength and tensile elongation of the molded product can be adopted as an index of the mechanical properties of the block copolymer.

(Molded body)
The molded article of the embodiment contains the block copolymer of the embodiment. The molded product of the embodiment is molded from the block copolymer of the embodiment.
The molded product of the embodiment can be made by using the block copolymer of the embodiment as a molding material.

The content ratio of the block copolymer of the embodiment with respect to the total mass of the molded product of the embodiment may be, for example, 50 to 100% by mass, 80 to 99.5% by mass, or 90 to 99% by mass. It may be there.

Examples of the method for producing a molded product include a method having a step of molding the block copolymer of the embodiment into a desired shape.

As the molding method, a method of molding the material containing the block copolymer of the embodiment by a solution casting method, extrusion molding, T-die molding, blow molding, injection molding or the like can be exemplified. The block copolymer of the embodiment can be molded into various shapes by selecting a molding method according to the desired shape of the molded product and the like.

As an example of the molded product of the embodiment, a film containing the block copolymer of the embodiment can be exemplified.
The thickness of the film or the porous film of the embodiment is not particularly limited, but may be, for example, 5 to 200 μm, 7 to 100 μm, or 10 to 50 μm. ..

Since the molded product of the embodiment contains the block copolymer of the embodiment, it has appropriate hydrophilicity, and the block copolymer of the embodiment has a large weight average molecular weight (Mw), so that it can be excellent in mechanical properties.

The tensile strength of the molded product obtained by molding the block copolymer of the embodiment is preferably 100 MPa or more, more preferably 101 MPa or more, still more preferably 103 MPa or more.
The upper limit of the tensile strength is not particularly limited, and for example, it may be 150 MPa or less, 130 MPa or less, or 120 MPa or less.
The upper limit value and the lower limit value of the tensile strength can be arbitrarily combined, and the tensile strength of the molded product obtained by molding the block copolymer of the embodiment may be, for example, 100 MPa or more and 150 MPa or less, and 101 MPa. It may be 130 MPa or more, and may be 103 MPa or more and 120 MPa or less.

The above tensile strength can be obtained by the method described in Examples.

The molded product of the block copolymer of the embodiment in which the tensile strength is equal to or higher than the lower limit value is further excellent in mechanical properties.

The tensile elongation of the molded product obtained by molding the block copolymer of the embodiment is preferably 6% or more, more preferably 7% or more, still more preferably 8% or more.
The upper limit of the tensile elongation is not particularly limited, and for example, it may be 30% or less, 20% or less, or 15% or less.
The upper limit value and the lower limit value of the tensile elongation can be arbitrarily combined, and the tensile elongation of the molded product obtained by molding the block copolymer of the embodiment may be, for example, 6% or more and 30% or less. It may be% or more and 20% or less, and may be 8% or more and 15% or less.

The tensile elongation can be obtained by the method described in Examples.
(Measurement of tensile properties of film)
Tensile strength and tensile elongation at break are measured according to JIS K7127. Using a JIS K6251 dumbbell-shaped No. 3 test piece obtained by punching a film with a thickness of 30 μm, the test piece was pulled by an autograph at a grip interval of 50 mm and a tensile speed of 5 mm / min, at 23 ° C. and a relative humidity of 50%. When the test piece is cut (broken) in an atmosphere, the tensile strength (the value obtained by dividing the tensile load value by the cross-sectional area of the test piece) and the tensile elongation (%) are measured.
The tensile elongation was calculated by the following formula. The larger the tensile elongation, the larger the film elongation.
Tensile elongation (%) = (L-Lo) / Lo × 100
Lo: Gripping interval before test (50 mm), L: Gripping interval at break (mm)

The molded product of the block copolymer of the embodiment in which the tensile elongation is equal to or higher than the above lower limit value is further excellent in mechanical properties.

As an example, the water permeability of the porous membrane of the molded product obtained by molding the block copolymer of the embodiment may be 1500 to 4500 L / m ² / h / 100 kPa, and 2000 to 30000 L / m ² / h / 100 kPa. It may be 2200 to 3500 L / m ² / h / 100 kPa.

The water permeability can be obtained by the method described in Examples.
(Measurement of water permeability of porous membrane)
A mixed solution of 18 parts by mass of aromatic polysulfone block copolymer and 82 parts by mass of NMP is applied to one surface of a glass plate having a thickness of 3 mm using a film applicator, and then dried at 60 ° C. using a high-temperature hot air dryer. Form a coating film. This coating film is heat-treated at 250 ° C. while flowing nitrogen to form a porous film having a thickness of 30 μm on a glass plate. Pure water is filtered through the obtained porous membrane at a pressure of 0.2 bar (20 kPa) at 23 ° C. using a pressure cell having a diameter of 47 mm, and from 7 minutes after the start of filtration to 7 minutes and 30 seconds. The amount of pure water that has permeated the porous membrane in (30 seconds) is measured to determine the water permeation rate.

The porous membrane having a water permeability of not less than the lower limit is more excellent in water permeability.

The block copolymer of the embodiment can be obtained by the method for producing the block copolymer of the above embodiment. According to the method for producing a block copolymer of the embodiment, the molecular weight of the produced block copolymer can be easily improved.

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

<Measurement of Mn and Mw and calculation of Mw / Mn in block copolymers, etc.>
The weight average molecular weight (Mw), number average molecular weight (Mn), and polydispersity (Mw / Mn) of each polymer (each block copolymer and raw material polyethylene glycol monomethyl ether) were determined by GPC measurement. Both Mn and Mw were measured twice, and the average value thereof was calculated as Mn and Mw, respectively, and the average value of Mw / Mn was obtained.
[Measurement condition]
Sample: 0.002 g of aromatic polysulfone is mixed with 1 mL of N, N-dimethylformamide solution containing 10 mM lithium bromide Sample injection amount: 100 μL
Column (stationary phase): Two "TSKgel GMHHR-H" (7.8 mmφ x 300 mm) manufactured by Tosoh Corporation are connected in series. Column temperature: 40 ° C.
Eluent (mobile phase): N, N-dimethylformamide containing 10 mM lithium bromide Eluent flow rate: 0.8 mL / min Detector: Differential refractive index meter (RI) + light scattering photometric meter (LS)
Standard reagent: Polystyrene Molecular weight calculation method: Absolute molecular weight is calculated from the measurement results of a light scattering photometer (LS).

<Measurement of film tensile properties>
Tensile strength and tensile elongation at break were measured according to JIS K7127. Using a JIS K6251 dumbbell-shaped No. 3 test piece obtained by punching a film with a thickness of 30 μm, the test piece was pulled by an autograph at a grip interval of 50 mm and a tensile speed of 5 mm / min, at 23 ° C. and a relative humidity of 50%. The tensile strength (the value obtained by dividing the tensile load value by the cross-sectional area of the test piece) and the tensile elongation (%) when the test piece was cut (broken) in an atmosphere were measured.
The tensile elongation was calculated by the following formula. The larger the tensile elongation, the larger the film elongation.
Tensile elongation (%) = (L-Lo) / Lo × 100
Lo: Gripping interval before test (50 mm), L: Gripping interval at break (mm)

<Measurement of water permeability of porous membrane>
Using a pressure cell with a diameter of 47 mm, pure water is filtered through the porous membrane at a pressure of 0.2 bar (20 kPa) at 23 ° C., and the pure water is filtered from 7 minutes after the start of filtration to 7 minutes and 30 seconds (30 seconds). ), The amount of pure water that permeated the porous membrane was measured to determine the water permeation rate.

<Manufacturing of block copolymers>
[Experimental Example 1]
In a polymerization tank equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a condenser with a receiver at the tip, 3.0 g of polyethylene glycol monomethyl ether (manufactured by Tokyo Kasei, weight average molecular weight 570), 0.46 g of potassium carbonate, and 150 g of N-methyl-2-pyrrolidone (NMP) is mixed, the temperature is raised to 100 ° C., and then the absolute weight measured with a DMF solvent by polyether sulfone (manufactured by Sumitomo Chemical Co., Ltd., Sumika Excel PES 5900P, gel permeation chromatography). (Average molecular weight of 30,000 or more) 100 g was added. After the polyether sulfone was dissolved, it was heated at 200 ° C. and reacted for 4 hours. The resulting reaction mixture was then diluted with NMP and cooled to room temperature to precipitate unreacted potassium carbonate and by-product potassium chloride. The above solution was added dropwise to water to precipitate aromatic polysulfone, and unnecessary NMP was removed by filtration to obtain a precipitate.
The obtained precipitate was carefully washed repeatedly with methanol and water and dried by heating at 150 ° C. to obtain an aromatic polysulfone block copolymer having polyethylene glycol at the end.

[Experimental Example 2]
Polyethylene glycol was terminated in the same manner as in Experimental Example 1 above, except that the molecular weight and compounding amount of the polyethylene glycol monomethyl ether used above were changed as shown in Table 1 (Tokyo Kasei Co., Ltd., weight average molecular weight 2200). The aromatic polysulfone block copolymer possessed by the above was obtained.

[Experimental Examples 3-4]
In Experimental Example 1, polyethylene glycol was prepared in the same manner as in Experimental Example 1 except that the blending amount of polyethylene glycol monomethyl ether was changed as shown in Table 1 and the reaction time was changed to 14 hours at 200 ° C. An aromatic polysulfone block copolymer having a terminal was obtained.

[Experimental Example 5]
81.79 g of 4,4'-dichlorodiphenyl sulfone (DCDPS), 4,4'-dihydroxydiphenyl sulfone (4,4'-dihydroxydiphenylsulfone) in a polymerization tank equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser with a receiver at the tip. 69.85 g of DHDPS), 11.40 g of polyethylene glycol monomethyl ether (weight average molecular weight 2200) and 41.35 g of potassium carbonate were suspended in 150 ml of NMP under a nitrogen atmosphere. The batch was heated to 190 ° C. within 1 hour and reacted for 6 hours. The resulting reaction mixture was then diluted with NMP and cooled to room temperature to precipitate unreacted potassium carbonate and by-product potassium chloride. The above solution was added dropwise to water to precipitate aromatic polysulfone, and unnecessary NMP was removed by filtration to obtain a precipitate.
The obtained precipitate was carefully washed repeatedly with methanol and water, and dried by heating at 150 ° C.

[Experimental Example 6]
In Experimental Example 1, polyethylene glycol monomethyl ether, potassium carbonate and N-methyl-2-pyrrolidone were added to a polymerization tank equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a condenser with a receiver at the tip. The same operation as in Experimental Example 1 was carried out except that 50 mL of toluene was added.

[Experimental Example 7]
In Experimental Example 2, polyethylene glycol monomethyl ether, potassium carbonate and N-methyl-2-pyrrolidone were added to a polymerization tank equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a condenser with a receiver at the tip. The same operation as in Experimental Example 2 was carried out except that 50 mL of toluene was added.

The weight average absolute molecular weight (Mw) and polydispersity (Mw / Mn) of the aromatic polysulfone block copolymers obtained in Experimental Examples 1 to 7 were measured. The results are shown in Table 1.

Experimental Examples 1 to 4 described above correspond to Examples to which the present invention is applied.

From the results shown in Table 1, the aromatic polysulfone block copolymers produced using the pre-polymerized aromatic polysulfone (a) of Experimental Examples 1 to 4 as raw materials are the aromatic polysulfone (a) of Experimental Example 5. ) Was shown to have a higher Mw value than the aromatic polysulfone block copolymer produced using the monomer as a raw material.

From the results shown in Table 1, the aromatic polysulfone block copolymers produced in Experimental Examples 1 to 4 without using a solvent that forms an azeotropic mixture with water are azeotropically heated with water in Experimental Examples 6 to 7. It has been shown to have higher Mw values than aromatic polysulfone block copolymers made using solvents that form the mixture.

<Making cast film>
In a heating vessel, 18 parts by mass of the aromatic polysulfone block copolymer of Experimental Example 1 and 82 parts by mass of NMP were mixed and stirred at 80 ° C. for 2 hours to obtain a pale yellow solution. This was applied to one surface of a glass plate having a thickness of 3 mm using a film applicator, and then dried at 60 ° C. using a high-temperature hot air dryer to form a coating film. This coating film was heat-treated at 250 ° C. while flowing nitrogen to form a film having a thickness of 30 μm on a glass plate. A film was obtained by peeling this film from a glass plate.
The values of tensile strength and tensile elongation were measured for the obtained Experimental Example 1 film.

The tensile strength of the film of Experimental Example 1 was 100 MPa, and the tensile elongation was 10%. The film of Experimental Example 1 had good tensile strength and tensile elongation values, and was shown to be excellent in mechanical properties.

<Preparation of porous membrane>
In a heating container, 18 parts by mass of the aromatic polysulfone block copolymer of Experimental Examples 1 to 4, 6 or 7 and 82 parts by mass of NMP were mixed and stirred at 80 ° C. for 2 hours to obtain a pale yellow solution. .. This was applied to one surface of a glass plate having a thickness of 3 mm using a film applicator, and then immersed in water to form a porous film of the aromatic polysulfone block copolymers of Experimental Examples 1 to 4, 6 and 7. .. This porous material was peeled off from the glass plate, washed with water multiple times, and then the membrane was stored in water until the start of measurement, and the water permeability was measured. The results are shown in Table 1.

According to the comparison between the porous membranes of Experimental Examples 1 and 3 and Experimental Example 6 and the comparison between the porous membranes of Experimental Examples 2 and 4 and Experimental Example 7, the same as that of water in Experimental Examples 1 to 4. The aromatic polysulfone block copolymer produced without using a solvent for forming a boiling mixture is more than the aromatic polysulfone block copolymer produced in Experimental Examples 6 to 7 using a solvent for forming a co-boiling mixture with water. However, it was shown that the water permeation rate was improved in each case, and it was possible to provide a film having excellent water permeation.

Each configuration in each embodiment and a combination thereof are examples, and the configuration can be added, omitted, replaced, and other changes are possible without departing from the spirit of the present invention. Moreover, the present invention is not limited to each embodiment, but is limited only to the scope of claims.

Claims (11)

1. A step of preparing an aromatic polysulfone (a) having at least one Cl atom at the terminal in advance, and
   It comprises a step of reacting the aromatic polysulfone (a) with a polyoxyalkylene compound (b) having at least one hydroxy group at the terminal in a solvent.
   A method for producing a block copolymer in which the ratio of the solvent forming an azeotropic mixture with water to the total amount of the solvent used in the reaction is 0 to 20% by mass.
2. The method for producing a block copolymer according to claim 1, wherein the weight average molecular weight of the aromatic polysulfone (a) obtained as an absolute molecular weight by gel permeation chromatography is 30,000 or more.
3. The block copolymer comprises an aromatic polysulfone block (A) and a polyoxyalkylene block (B).
   The method for producing a block copolymer according to claim 1 or 2, wherein the block copolymer has a weight average molecular weight of 40,500 to 70,000, which is obtained as an absolute molecular weight by gel permeation chromatography.
4. A linear triblock copolymer having the above three blocks, and the polyoxyalkylene block (B) in the order of the polyoxyalkylene block (B), the aromatic polysulfone block (A), and the polyoxyalkylene block (B). A linear diblock copolymer having the above two blocks of B) and the aromatic polysulfone block (A),
   The method for producing a block copolymer according to claim 3, which comprises at least one of the above.
5. The method for producing a block copolymer according to claim 3 or 4, wherein the aromatic polysulfone block (A) is composed of a polymer chain having a structural unit represented by the following formula (1).
   

   

   [In equation (1),
   R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom.
   n1 and n2 are independently integers of 0 to 4, respectively.
   When n1 or n2 is 2 or more, plural R ¹ and R ² may be the same or different from each other. ]
6. The method for producing a block copolymer according to any one of claims 3 to 5, wherein the polyoxyalkylene block (B) is composed of a polymer chain having a structural unit represented by the following formula (2-1).
   

   
7. A block copolymer containing an aromatic polysulfone block (A) and a polyoxyalkylene block (B).
   A block copolymer having a weight average molecular weight of 40,500 to 70,000, which is obtained as an absolute molecular weight by gel permeation chromatography.
8. ¹ The block copolymer according to claim 7, wherein the number average molecular weight of the polyoxyalkylene block (B) calculated by 1 H-NMR is 5000 or less.
9. A linear triblock copolymer having the above three blocks, and the polyoxyalkylene block (B) in the order of the polyoxyalkylene block (B), the aromatic polysulfone block (A), and the polyoxyalkylene block (B). A linear diblock copolymer having the above two blocks of B) and the aromatic polysulfone block (A),
   The block copolymer according to claim 7 or 8, which comprises at least one of.
10. The block copolymer according to any one of claims 7 to 9, wherein the aromatic polysulfone block (A) comprises a polymer chain having a structural unit represented by the following formula (1).
    

    

    [In equation (1),
    R ¹ and R ² independently represent an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or a halogen atom.
    n1 and n2 are independently integers of 0 to 4, respectively.
    When n1 or n2 is 2 or more, plural R ¹ and R ² may be the same or different from each other. ]
11. The block copolymer according to any one of claims 7 to 10, wherein the polyoxyalkylene block (B) is composed of a polymer chain having a structural unit represented by the following formula (2-1).