JPH04189830A - Arylene sulfide-based block copolymer and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a novel arylene sulfide block copolymer and a method for producing the same.

More specifically, the present invention is suitable as a material for various molded products, films, fibers, electric/electronic parts, etc., has excellent heat resistance, moldability, dimensional stability, etc., and is compatible with other resins and/or inorganic materials. The present invention relates to an aurene sulfide block copolymer that has good adhesion and/or adhesion and/or compatibility with fillers, and a method for producing the same.

(Prior Art) As a method for producing an amonolene sulfite copolymer having a carboxyl group, for example, in a polar solvent, (1) a dihalogeno aromatic compound, (2) an alkali metal sulfide, and (3) ) A method of contacting a dihalogeno aromatic carboxylic acid and/or an alkali metal salt thereof is disclosed in JP-A-63
It is disclosed in JP-305131. However, the dihalogeno aromatic compound used here does not mention any dihalogeno aromatic sulfones, and thus has a composition different from that of the copolymer of the present invention. In addition, in this method, the obtained polymer is essentially a random copolymer, and as the proportion of units having carboxyl groups increases, physical properties such as a decrease in melting point and a decrease in mechanical strength such as impact strength and bending strength occur. There's a possibility.

Further, JP-A-62-115030 discloses a polyphenylene sulfide (hereinafter abbreviated as PPS) part and an aromatic sulfide sulfone polymer (substantially the same as polyphenylene sulfide sulfone) part, and has a logarithmic viscosity [η ] (Here, [6 mouths is the value measured at 206 ° C in α-chloronaphthalene at a polymer concentration of 0.4 g / room ml solution, and calculated according to the following formula [η] = 1n (relative viscosity) / polymer concentration A block copolymer is disclosed in which .

However, since this block copolymer does not contain phenylene sulfide (or phenylene sulfide sulfone) having a carfoquinol group as an essential block copolymer component, the resulting copolymer has poor adhesion with other resins and/or inorganic fillers. Adhesion or compatibility cannot be said to be sufficient.

(Problems to be Solved by the Invention) The present invention solves the problems that cannot be solved with the conventional technology as described above, and has excellent heat resistance, moldability, dimensional stability, etc., and is compatible with other resins and/or It is an object of the present invention to provide a carboxyl group-containing arylene sulfide block copolymer that has good adhesion and/or adhesion and/or compatibility with inorganic fillers, and to provide an industrially advantageous production method thereof. purpose.

(Means for Solving the Problems) The present inventors have made extensive studies to achieve the above object, and have completed the present invention.

That is, the present invention provides (A) a polyphenylene sulfide (hereinafter abbreviated as PPS) moiety, (B) a polyphenylene sulfide sulfone (hereinafter abbreviated as PP5S) moiety, and (C) a polyphenylene sulfide containing a carboxyl group (hereinafter abbreviated as c-
pps) and polyphenylene sulfide sulfone containing hacarboxyl group (hereinafter abbreviated as c-ppss)
3, such as a polyarylene sulfide (hereinafter collectively referred to as C-PAS) moiety containing a carboxyl group such as
Consisting of two parts, 316℃, 10rad/s e
An arylene sulfide-based product characterized in that the dynamic viscosity [η°] at c is in the range of 10 to 10' poise,
The present invention provides a copolymer and a method for producing the same.

The block copolymer provided by the present invention preferably contains 70 mol% or more, more preferably 90 mol% or more of the structural units constituting the block copolymer provided by the present invention. If the repeating unit is less than 70 mol%, it is difficult to obtain a block copolymer with excellent properties. . Also, the above PP
If the S moiety is less than 30 mol% of the repeating S units,
It is possible to copolymerize repeating units having the following structural formula.

ppss constituting the block copolymer provided by the present invention
It is preferable that the portion contains the structural unit represented by 70 mol % or more, more preferably 90 mol % or more, and if the repeating unit is less than 70 mol %, it is difficult to obtain a block copolymer with excellent properties. In addition, the above PP5S part has 30 repeating units.
If the amount is less than mol %, it is possible to copolymerize repeating units having the following structural formula.

C-PA constituting the block copolymer provided by the present invention
The S portion preferably contains at least 70 mol%, more preferably at least 90 mol%, of the structural unit represented by the general formula, and if the repeating unit is less than 70 mol%, it is difficult to obtain a block copolymer with excellent properties for the purpose of the present invention. . In C-PASO, C-PP5 is preferred, and if the C-PAS moiety is less than 30 mol% of the repeating units, it is possible to copolymerize repeating units having the following structural formula. be. Also, C
The use of 2,4-dichlorobenzoic acid as the main raw material for the -PAS moiety is inexpensive and industrially advantageous.

In addition, the ratio of the repeating part of PPS, the repeating part of PP5S, and the repeating part of C-PAS was 316°C, 10r
If the dynamic viscosity [η' is 10-10' poise, the PPS part and P
The molar ratio of the P S-3 moieties is from 99.9:0.1 to 0.1:99.9, more preferably from 99:1 to 1=99. Furthermore, the molar ratio of (pps part, 1,000 PPPSS part) and C-PAS part is preferably 99.9.
:・0.1 to 70:30, more preferably 99°5:0.5 to 85:15. 99. , 9:0
If the repeating portion of C-PAS is less than the ratio of 1, the effect of improving adhesion and/or adhesion and/or compatibility with other resins and/or inorganic fillers, which is one of the objectives of the present invention. is small (and also, C-P is smaller than the 70:30 ratio
If there are many repeated parts of AS, it is not preferable because there is a possibility that the heat resistance and mechanical strength will decrease.

In addition, the repeating part of PPS was heated at 300℃ and 10rad.
/sec dynamic viscosity [η'] is preferably 10 to 105 poise, more preferably 20 to 50,000 poise
It's Poise Deru. If it is less than 10 poise, heat resistance and mechanical strength, which are one of the objects of the present invention, will deteriorate, which is undesirable, and if it exceeds 105 poise, moldability will deteriorate, which is not preferred. Also, 316 of the repeated part of PP5S
Dynamic viscosity [η'] at °C, 10 rad/sec
is preferably 1o-io' poise, more preferably 20
~50,000 poise. If the dynamic viscosity [η'] is less than this range, heat resistance and mechanical strength, which are one of the objectives of the present invention, will deteriorate, which is undesirable, and if it exceeds this range, moldability will deteriorate, which is undesirable. .

Further, it is preferable that the average degree of polymerization of both the repeating portion of PPS and the repeating portion of pps s is 20 or more.

As a method for producing this block copolymer, (1) PP
(2) PPS prepolymer, in which the dihalogeno aromatic sulfone and the sulfidating agent are reacted in a polar solvent in which the S prepolymer is present, and then the dihalogeno aromatic carboxylic acid and/or its alkali metal salt is reacted with the sulfidating agent. (3) reacting the dihalogeno aromatic carboxylic acid and/or its alkali metal salt with the sulfidating agent, and then reacting the dihalogeno aromatic sulfone with the sulfidating agent in a polar solvent in which the PPSS prepolymer is present; In a polar solvent, dino-lobenzene and a sulfidating agent are reacted, and then a dihalogeno aromatic carboxylic acid and/or its alkali metal salt and a sulfidating agent are reacted. (4) In a polar solvent in which the ppss prepolymer is present. , reacting the dihalogeno aromatic carboxylic acid and/or its alkali metal salt with the sulfidating agent, and then reacting the dihalobenzene with the sulfidating agent, (
5) In a polar solvent in which C-PAS prepolymer is present,
(6) reacting the dihalogeno aromatic sulfone with the sulfidating agent in a polar solvent in which the C-PAS prepolymer is present; (7) PPS prepolymer and PP are then reacted with dihalobenzene and a sulfidating agent in a polar solvent.
There are methods such as reacting a 5S prepolymer and a C-PAS prepolymer.

In the above method, the polar solvent in which the prepolymer is present can be prepared by, for example, preparing the polar solvent in which the PPS prepolymer is present by reacting a sulfidating agent with dihalobenzene in a polar solvent, or The solvent can be prepared by reacting the sulfidating agent with the dihalogeno aromatic sulfone in a polar solvent.
The polar solvent in which the prepowamer is present may be prepared by reacting the sulfidating agent with the dihalogeno aromatic carboxylic acid and/or its alkali metal salt in a polar solvent.

The polar solvent used in the present invention is preferably an organic polar solvent that is substantially liquid at the reaction temperature and pressure. Specifically, formamide, acetamide, N-methylformamide, N,N-dimethylacetamide, N,N-dimethylformamide, N-ethylpropionamide, N,N-dipropylbutyramide, 2-pyrrolidone, N-methyl -2-pyrrolidone, ε-caprolactam, N-methyl-ε-caprolactam N.

N'-ethylenedi-2-pyrrolidone, hexamethylphosphoramide, tetramethylurine L 1,3-dimethyl-
Amides such as 2-imidazolidinone, urea and lactams; sulfolane, dimethylsulfolane, 1-methyl-1
- Sulfolanes such as oxosulfolane and 1-phenyl-1-oxosulfolane; Nitriles such as benzonitrile; Ketones such as methyl phenyl ketone; 1-methyl-1
-oxophosphane, 1-n-n-propyl-1-oxophosphane, 1-phenyl-1-oxoposphane and other cyclic organic phosphorus compounds, and mixtures thereof. Among these solvents, amides and lactams are preferred, and N-methylpyrrolidone is particularly preferred. The amount of polar solvent used in each step is 1 to 20% by weight relative to the total amount of raw materials such as dihalobenzene, dihalogeno aromatic sulfone, dihalogeno aromatic carboxylic acid and/or its alkali metal salt, and sulfidating agent.
, preferably from 2 to ]0.

If the amount of the solvent (1) is less than 1, the reaction may become non-uniform, which is not preferable, and although it is possible to use more than 20, this is not preferable from the viewpoint of decreased productivity.

The dihalohensen used in the present invention is -
Examples include compounds represented by (I).

(Xl and X2 in the formula are each a halogen atom,
They may be the same or different.

) Specific examples of the compounds represented by -maximum (I) above include:
Examples include p-dihalobenzene, m-dihalobenzene, and 0-dihalobenzene. The two halogen elements in dihalobenzene are fluorine, chlorine, bromine, or iodine, and may be the same or different. Among the above dihalobenzenes, p
-dihalobenzene is preferred, and p-dichlorobenzene is particularly preferred.

Examples of the dihalogeno aromatic sulfone used in the present invention include compounds represented by -maximum (n).

(Xl and X2 in the formula are each a halogen atom,
They may be the same or different.

) Specific examples of the compound represented by (II) above include dihalogenodiphenylsulfones such as 4,4'-dihalogenodiphenylsulfone. The two halogen elements in these dihalogeno aromatic sulfones are fluorine, chlorine, bromine, or iodine, and they may be the same or different from each other. Among the above dihalogenodiphenylsulfones, 4,42-dichlorodiphenylsulfone is particularly preferred.

As the dihalogeno aromatic carboxylic acid and its alkali metal salt used in the present invention, for example - maximum (m)
(rV) (in the formula, xl and x2 are each a halogen atom,
They may be the same or different from each other. R is a hydrogen atom or an alkali metal. ) and the like.

Specific examples of the compound represented by the above formula (m) include 2
, 3-dihalobenzoic acid, 2,4-dihalobenzoic acid, 2,
5-dihalobenzoic acid, 2,6-dihalobenzoic acid, 3,4
-Dihalobenzoic acids such as dihalobenzoic acid and 3,5-dihalobenzoic acid, and alkali metal salts thereof.

Specific examples of the compound represented by the above formula (IV) include:
4,4''-dihalodiphenylsulfone-2-carboxylic acid, 4.4'-dihalodiphenylsulfone-
3-carboxylic acid, 2. 4'-dihalodiphenylsulfone-(3,4,5 or 6)-carboxylic acid, 3. 4
'-dihalodiphenylsulfone-(2,4,5 or 6)-carboxylic acid, 2,4'-dihalodiphenylsulfone-(2', 3', 5' or 6')-carboxylic acid, 3,4 ' -dihalodiphenylsulfone- (2', 3
', 5' or 6')-carvone L 2,3° -
Dihalodiphenylsulfone-(2', 4", 5' or 6')-carboxylic acid, 2. 3-Dihalodiphenylsulfone-(4,5 or 6)-carboxylic acid, 3,3'-
Dihalodiphenylsulfone-(2,4,5 or 6)-
Carvone L 2,2'-dihalodiphenylsulfone-(3,4,5 or 6)-carboxylic acid and alkali metal salts thereof.

As mentioned above, the two halokene atoms in the dihalogeno aromatic carboxylic acid and its alkali metal salt are fluorine, chlorine, bromine, or iodine, and these may be the same or different from each other. good.

Furthermore, it is also possible to use compounds in which one or more carboxyl groups are further introduced into appropriate positions of each of the above compounds.

In the present BJ'J, each of the dihalogeno aromatic carboxylic acids and alkali metal salts thereof may be used alone, or two or more thereof may be used in combination.

Among the dihalogeno aromatic carboxylic acids and alkali metal salts thereof, dihalobenzoic acids and alkali metal salts thereof are preferred, and in particular, 2,4-
Preference is given to using dichlorobenzoic acid and its sodium salt.

In addition, the above-mentioned dihalobenzene, dihalogeno aromatic sulfone,
In the and dihalogeno aromatic carboxylic acids, a functional group with low reactivity such as an alkyl group or an alkoxy group may be introduced into the aromatic ring without departing from the purpose of the present invention.

The sulfidating agent used in the present invention includes an alkali metal sulfide; a combination of an alkali metal hydrosulfide compound and sodium hydroxide, and the like.

Examples of alkali metal sulfides include lithium sulfide,
Examples include sodium sulfide, potassium sulfide, rubidium sulfide, and cesium sulfide. Each of these may be used alone, or two or more types may be used in combination. Furthermore, the alkali metal sulfide mentioned above may be used as an anhydride, a hydrate, or an aqueous solution, but when using a hydrate or an aqueous solution, it is better to perform a dehydration operation before the reaction as described below. .

Among the alkali metal sulfides, sodium sulfide and potassium sulfide are preferred, and sodium sulfide is particularly preferred.

Examples of the alkali metal hydrosulfide compound used in the present invention include lithium bisulfide, sodium bisulfide, potassium bisulfide, rubidium bisulfide, cesium bisulfide, etc., and each of these may be used alone, or Two or more types may be mixed and used. Further, the above-mentioned alkali metal hydrosulfide compound may be used as an anhydride, a hydrate, or an aqueous solution, but when a hydrate or an aqueous solution is used,
As in the case of alkali metal sulfides, it is better to perform a dehydration operation before the reaction, as described below.

Among the alkali metal hydrosulfide compounds, sodium hydrosulfide and potassium hydrosulfide are preferred, and sodium hydrosulfide is particularly preferred.

Examples of the alkali metal hydroxide used in the present invention include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, etc. Each of these may be used alone, or A mixture of more than one species may be used.

Among the above alkali metal hydroxide compounds, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferred;
Particularly preferred is sodium hydroxide.

The polymerization reaction in the method of the present invention is preferably carried out in an anhydrous system, especially in the initial stage, or the sulfitizing agent's sulfur source (
Water may be present in an amount up to about 5 times the molar amount of the total amount of alkaline earth metal sulfide and alkali metal hydrosulfide compound used in the reaction. There is also no particular restriction on the order of addition of each raw material when prepolymer is prepared in a polar solvent, but if an alkali metal sulfide is used as a sulfiding agent, it may be necessary to pre-prepare it in the polar solvent during this reaction. After dehydrating the originally contained water of hydration by a dehydration operation such as azeotropic distillation, dihalobenzene, dihalogeno aromatic sulfone, dihalogeno aromatic carboxylic acid and/or its alkali metal salt is added to prepare the reaction solution. It is preferable to do so.

In addition, when using a combination of an alkali metal hydrosulfide compound and an alkali metal hydroxide as a sulfidizing agent, the alkali metal hydrosulfide compound and alkali metal hydroxide are reacted in advance in a polar solvent during this reaction. After preparing a dehydrated mixture of water and the originally contained hydration water by a dehydration operation such as azeotropic distillation, this is mixed with dihalobenzene, dihalogeno aromatic sulfone, dihalogeno aromatic carboxylic acid and/or its alkali metal salt. It is preferable to adjust the reaction solution by adding .

In the above-mentioned method of the present invention, the reaction may be carried out in the presence of a catalyst if necessary. Examples of the catalyst used include lithium halides such as lithium chloride and lithium bromide; lithium carboxylates such as lithium oxyoxide and lithium acetate; and lithium compounds such as lithium carbonate, lithium oxide, and lithium sulfide. Among the above lithium compounds, lithium chloride, lithium acetate, and lithium carbonate are preferred. In the present invention, each of the above lithium compounds may be used alone, or two or more types may be used in combination.

The usage ratios of the above various raw material components in the present invention are: a mol for dihalobenzene, b mol for dihalogeno aromatic sulfone, and c mol for dihalogeno aromatic carboxylic acid and/or its alkali metal salt.
When expressed as mol, usually 0.001≦b/(a+b)≦
0.999, preferably 0.01≦b/(a+b
)≦0.99, and 0.001≦c/(a+b+
c)≦0.5, preferably 001≦c/(a+b
10c)≦04, more preferably 0.02≦c/(a+
b+c)≦0.3. If the proportion of this dihalogeno aromatic carboxylic acid and/or its alkali metal salt component used is too small and deviates from the above range, the resulting polymer may be filled with other resins and/or inorganic fillers of the copolymer that is the object of the present invention. If the effect of improving adhesion and/or adhesion and/or compatibility with the material is not sufficiently exhibited, and the proportion of the dihalogeno aromatic carboxylic acid and/or its alkali metal salt component is too high, the obtained polymer This is undesirable because the heat resistance or mechanical strength of the material decreases.

In addition, the total amount of dihalobenzene, dihalogeno aromatic sulfone, dihalogeno aromatic carboxylic acid and/or its alkali metal salt in each step of the reaction, and the sulfur source of the sulfidating agent (the alkali metal sulfide used in the reaction and the alkali metal hydrogen sulfide) The usage ratio of the total compound ji) is usually 0.7, assuming that each is d mol and e mol.
5≦d/e≦20, preferably 0,90≦d
/e≦1.2.

Furthermore, dihalogeno aromatic carboxylic acid (Cmol)
When using alkali metal hydroxide, it is preferable to carry out the reaction by adding an alkali metal hydroxide into the system.If the reaction is carried out by adding an excessive amount of alkali metal hydroxide in this way, the side effects of the carboxyl group of the dihalogeno aromatic carboxylic acid It has the effect of preventing reactions. In addition, alkali metal hydrosulfide compounds (e so mol) and alkali metal hydroxides (e so mol) are used as sulfidizing agents.
oHmol), it is preferable to further add an alkali metal hydroxide corresponding to the amount of the dihalogeno aromatic carboxylic acid used so that (e OHe 3H)≧C.

Furthermore, when a lithium compound or the like is used as a catalyst, if the catalyst is f mol, then the sulfidating agent (the total amount of the alkali metal sulfide and the alkali metal hydrosulfide compound used in the reaction) e mol, usually, f/e
≦2.0, preferably f/e≦16. If the amount of this catalyst exceeds the above range, the catalytic effect will not be sufficiently exerted in proportion to the amount, and the catalyst may remain at a high concentration in the produced copolymer, which may complicate the cleaning process. unfavorable in terms of

Next, an example of a preferred method among the embodiments of the method for producing the professional copolymer of the present invention will be shown. First, an alkali metal hydrosulfide compound and an alkali metal hydroxide are mixed in a polar solvent, and the necessary After heating and dehydrating by azeotropic distillation etc., dihalobenzene is added, usually 150 to 3
00'C1 Preferably heated to a temperature of 180-280'C. 1 to 40 hours, preferably 0. 5-2
A polymerization reaction is performed by heating for 0 hours to prepare a reaction solution containing a PPS prepolymer. Further, an alkali metal hydrosulfide compound, an alkali metal hydroxide and/a halogeno aromatic sulfone are added simultaneously or separately to this reaction solution.
Heating to a temperature of ~300°C, preferably 180-280°C for 0.1-40 hours, preferably 0. A polymerization reaction is performed by heating for 5 to 20 hours to prepare a reaction solution containing a block prepolymer consisting of a PPS portion and a ppss portion. Further, an alkali metal hydrosulfide compound, an alkali metal hydroxide, and a dihalogeno aromatic carboxylic acid are added simultaneously or separately to this reaction solution, and the temperature is usually 150 to 300°C.
, preferably heated to a temperature of 180 to 280°C.
1 to 40 hours, preferably 0. The polymerization reaction is carried out by heating for 5 to 20 hours. If the reaction temperature is less than 150°C, the reaction rate will be slow and the reaction may become non-uniform, which is undesirable. On the other hand, if it exceeds 300°C, side reactions such as decomposition of carboxyl groups or deterioration of the produced polymer may occur. etc., which is not desirable. In addition, the reaction time cannot be absolutely defined because it depends on the type and amount of raw materials used or the reaction temperature, but 0. If the reaction time is less than 1 hour, the amount of unreacted components will increase or the resulting polymer will likely have a low molecular weight, which is undesirable, and if it exceeds 40 hours, the productivity will decrease, which is undesirable.

This polymerization reaction is usually preferably carried out under an inert gas atmosphere such as nitrogen, helium, or argon, and nitrogen is particularly preferred from the viewpoint of economy and ease of handling.

There is no particular restriction on the reaction pressure, as it depends on the types and amounts of the raw materials and solvents used, the reaction temperature, etc., so there is no particular restriction, but it is usually at the autogenous pressure of the polymerization reaction system or below 40 kg/cm''. It is preferable to do so.

In addition, the adjustment of the reaction solution and the reaction for producing the block copolymer may be a one-stage reaction carried out at a constant temperature, a multi-stage reaction in which the temperature is raised stepwise, or a reaction in which the temperature is continuously changed. Any form of reaction is fine.

The produced copolymer may be directly separated after the reaction is completed by a commonly used method such as filtration or centrifugation, or after the reaction is completed, the reaction solution may be separated from the solvent used in the reaction,
It may be added to water or an aqueous acid solution and then separated by a method such as filtration.

The isolated copolymer is then treated with water or warm water, or an organic solvent with a relatively low boiling point such as methanol, ethanol, acetone, ether, or THF to remove the raw materials adhering to the copolymer. Washed by. Furthermore, using a relatively dilute aqueous acid solution during cleaning is effective in removing adhering sodium hydroxide, etc., and dilute hydrochloric acid is particularly preferred from the viewpoint of ease of handling and economical efficiency. The thus isolated copolymer is dried by heating to a temperature at which the solvent such as water substantially evaporates.

Drying may be carried out under vacuum, in air or under an inert gas atmosphere such as nitrogen.

The copolymers obtained in this way can be used as they are as various molding materials, etc., or they can be thickened by heat treatment in air or oxygen-enriched air. After the viscosity increasing operation, it may be used in various molding materials, etc.

Further, it is preferable that this heat treatment is carried out at a temperature of 150°C or higher; a temperature lower than 150'C is not preferable because the rate of thickening is very slow and productivity is poor. In addition, it is not preferable to perform heat treatment at a temperature higher than the temperature at which the polymer melts, since this will impair operability. That is, when the proportion of the PP5S moiety in the copolymer is high, the glass transition temperature (216°C
) It is preferable to carry out the process at a temperature below about 100 mL.

The fact that the copolymerization reaction product resulting from the blocking reaction is a chemically bonded PPS, ppss, and C-PAS nofloc copolymer indicates that the resulting polyester -(7) N- which is a good solvent for the alkali metal salt of C-PAS
After repeated extraction with methylpyrrolidone/water (3:2 weight ratio) mixed solvent, although the alkali metal salt of C-PAS was no longer contained in the extract, the presence of this component in the polymer was confirmed. You can confirm it by being there. on the other hand,
Whether unreacted PPS is contained in the copolymerization reaction product can be determined by performing fractional precipitation of the product using α-chloronaphthalene, which is a good solvent for PPS, and checking whether PPS homopolymer is present. In addition, to determine whether unreacted PP5S is contained in the copolymerization reaction product, the product is subjected to fractional precipitation using phenol/tetrachloroethane, which is a good solvent for PP5S, and whether PP5S homopolymer is present. You can check whether it is true or not.

During the production of the block copolymer, branching agents or molecule 1 regulators such as active hydrogen-containing halogen aromatic compounds, polyhalogen aromatic compounds, halogen aromatic nitro compounds, etc., as necessary, within the scope of the purpose of the present invention; The reaction can also be carried out by appropriately selecting polymerization additives such as metal salts, reducing agents, inert organic solvents, etc. and adding them to the reaction system.

The above-mentioned active hydrogen-containing halogeno aromatic compound refers to a halogeno aromatic compound having a functional group having active hydrogen such as an amine group, a thiol group, a hydroxyl group, etc.
Specifically, 2,3-dichloroaniline, 2,4-dichloroaniline, 2゜5-dichloroaniline, 2,6-
Dihaloanilines such as dichloroaniline; 2,3.4-
Trichloroaniline, 2. 3. 5-trichloroaniline, 2. 3. 6-trichloroaniline, 2. 4
．． 5-trichloroaniline, 2. 4. 6-trichloroaniline, 3. 4. Trihaloanilines such as 5-1-dichloroaniline; 2. a, 4. 5-
Tetrachloroaniline, 2. 3. 5. Tetrahaloanilines such as 6-tetrachloroaniline; 2,2
Dihalodiamino diphenyl ethers such as '-diamino-4,4'-dichlorodiphenyl ether, 2,4'-diamino-2', and 4-dichlorodiphenyl ether; and these compounds in which the amine group is substituted with a thiol group or a hydroxyl group. Examples include compounds that have been Also,
It is also possible to use active hydrogen-containing halogen aromatic compounds in which a hydrogen atom bonded to a carbon atom forming an aromatic ring in these active hydrogen-containing halogen aromatic compounds is substituted with an inert group such as an alkyl group. Among these various active hydrogen-containing halogen aromatic compounds, active hydrogen-containing dihalogeno aromatic compounds are preferred, and dichloroaniline is particularly preferred.

The above-mentioned polyhalogeno aromatic compound is a compound in which an aromatic ring is substituted with three or more halogen atoms, and specifically, 1. 2. 4-Trichlorobenzene, l, 3.
Examples include 5-trichlorohensen, 1,4°6-trichloronaphthalene, and the like.

Further, the above-mentioned halogeno aromatic nitro compound is a compound in which an aromatic ring having a nitro group is substituted with a halokene atom, and specifically, 2,4-dinitrochlorobenzene, 2
, 5-dichloronitrobenzene; dihalonitrodiphenyl ethers such as 2-nitro-4,4'-dichlorodiphenyl ether; 3゜3'-dinitro-4,4''-dichlorodiphenyl sulfone, etc. Dihalonitrodiphenyl sulfones;
2,5-dichloro-3-ditropyridine, 2-chloro-
Examples include mono- or dihalonitropyridines such as 3,5-dinitropyridine; and various dihalonitronaphthalenes.

By using these active hydrogen-containing halokene aromatic compounds, polyhalogen aromatic compounds, halogeno aromatic nitro compounds, etc., it is possible to increase the degree of branching and molecular weight of the resulting copolymer as necessary. It is possible to improve various physical properties of the copolymer, such as reducing the residual salt content or reducing the residual salt content.

In addition to the above-mentioned compounds, compounds having three or more reactive halogen atoms, such as cyanuric chloride, can also be used as branching agents or molecular TG regulators. In the present invention, one type of these branching agents or molecular weight regulators may be used alone, or two or more types may be used in combination.

Polymerization additives such as the metal salts mentioned above include metal carboxylates such as 9um acetate, potassium acetate, and zinc acetate; alkali metal mineral salts such as sodium phosphate, alkaline earth metal mineral salts; benzene. Examples include alkali metal sulfonates such as sodium sulfonate. These metal salts may be used alone or in combination of two or more.

Examples of the reducing agent include sodium thiosulfate, sodium sulfite, hydrazine, and metal hydrides. Among these, sodium sulfite is preferred.

Furthermore, as the above-mentioned inert solvent, benzene, toluene,
Hydrocarbons such as xylene, biphenyl, and anthracene, ethers such as polyethylene glycol, etc. can be mentioned, and among these, solvents with high boiling points are preferred since the reaction is carried out at a relatively high temperature.

The book copolymer obtained by the present invention can be directly processed into molded products with excellent heat resistance, moldability, dimensional stability, etc. by various melt processing methods such as injection molding, extrusion molding, compression molding, and blow molding. It can be done. However, in order to further improve performance such as strength, heat resistance, and dimensional stability, it is also possible to use it in combination with various fillers as long as the purpose of the present invention is not impaired.

Examples of the filler include fibrous fillers and inorganic fillers. Examples of fibrous fillers include glass fiber, carbon fiber,
Silane glass fibers, ceramic fibers, aramid fibers, metal fibers, fibers such as potassium titanate, silicon carbide, calcium sulfate, calcium silicate, natural fibers such as wollastonite, etc. can be used. Inorganic fillers include barium sulfate, calcium sulfate, clay, pyroferrite,
Hentonite, sericite, theolite, mica, mica, talc, atalbulgite, ferrite, calcium silicate, calcium carbonate, magnesium carbonate, glass peas, etc. can be used.

Furthermore, the following synthetic resins and elastomers can be mixed and used in the same manner. These synthetic resins include polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyether sulfoso, polyether ether ketone, polyether ketone, polyarylene, polytetrafluoroethylene, polyethylene Examples of the elastomer include fluorinated ethylene, polystyrene, ABS resin, epoxy resin, silicone resin, phenol resin, urethane resin, and the like. Examples of the elastomer include polyolefin comb, fluororubber, and silicone rubber.

In addition, small amounts of mold release agents, colorants, heat stabilizers, ultraviolet stabilizers, foaming agents, rust preventives, flame retardants, lubricants, and cups may be used as additives during molding without departing from the purpose of the present invention. A ring agent can be included.

The block copolymer of the present invention can be used in various molded products, films,
It can be used as a material for textiles, electrical/electronic parts, etc.

(Examples) The present invention will be specifically explained below using Examples, but the present invention is not limited only to these Examples.

Example 1 21 N-methylpyrrolidone (NMP) was added to an autoclave.
) 390g5N a S H・1. 5 H2O10
7.9 g (1°3 mol), sodium hydroxide 52.
0 g (1.3 mol) was prepared and heated under nitrogen atmosphere for 20
The water-NMP mixture was distilled off by raising the temperature to 0°C. Next, p-cyclooo benzene 191.1 was added to this system.
A solution prepared by dissolving 1.3 mol of NMP in 150 g of NMP was added thereto, and the mixture was reacted at 220°C for 5 hours and then at 240°C for 2 hours under a nitrogen atmosphere. This reaction solution A was cooled to about 80°C, and 143.5 g (0.50 mol) of 4.4'-dichlorodiphenylsulfone, NaS
H・1. 5 H2O41.5g (0°50mol)
, sodium hydroxide 20.0g (0.50mol)
and 200 g of NMP were added thereto, and the mixture was reacted at 200°C for 6 hours under a nitrogen atmosphere. Further, this reaction solution was cooled to about 80°C, and 38.2% of 2,4-dichlorobenzoic acid was added.
g (0.20 mol), N a S H・1. 5
6.6 g (0.20 mol) of H20, 16.0 g (0.40 mol) of sodium hydroxide, and 80 g of NMP were added, and the mixture was reacted at 220° C. for 5 hours and at 240° C. for 2 hours under a nitrogen atmosphere. After cooling the reaction vessel, the contents were taken out. The obtained reaction product was washed once with water. After drying the obtained cake under reduced pressure at 80°C, NMP/water (3:2
Weight ratio) Disperse in a mixed solvent and heat unreacted C at 80°C.
- PP5 was extracted and removed. This operation was repeated three times C-
It was confirmed that PP5 was not extracted at all. Furthermore, the cake obtained after the extraction was thoroughly washed successively with hot water and methanol and dried. Next, phenol/1. Using 1°2.2-tetrachloroethane (3:2 weight ratio), the soluble components were dissolved at 100°C and the filtration operation was repeated to filter and separate and remove only unreacted PP5S. Furthermore, the cake obtained after the extraction was thoroughly washed successively with hot water and methanol and dried. Next, using α-chloronaphthalene, the soluble components were dissolved at 2105C and the filtration operation was repeated to filter and separate and remove only unreacted PPS. The obtained cake was washed with methanol, treated with diluted hydrochloric acid, then thoroughly washed successively with hot water and methanol, and then dried under reduced pressure at 80°C to obtain a white powdery polymer. The glass transition point of this polymer is 836C and 207℃, the melting point is 270℃, and the
Dynamic viscosity measured at 6°C and 10 rad/sec [
η゛] was 150 to 250 poise.

Furthermore, when we measured the infrared absorption spectrum of this polymer, no peaks other than pps, ppss, and C-PP5 absorption were observed, and from the strength of the characteristic absorption seen at 1690 cm'' and the results of elemental analysis, it was found that the polymer P inside
The molar ratio of P S/P P S S/C-PPS is 68.
It was confirmed that the ratio was 3:25.2:6.5. Furthermore, when this Bommer is heat-treated at 250°C for 1 hour, it becomes 316°.
Dynamic viscosity measured at Cs 10 rad/see [
η'] was 400 to 600 poise.

Example 2 The amount of p-dichlorobenzene in the first stage was 132.3 g.
(0.9 mol), N a S H・1. 5 H20
The amount of 74.8 g (0.9 mol), the amount of NMP 40
0g and the amount of sodium hydroxide is 36.0g (0.9m
ol), the amount of 4,4'-dichlorodiphenylsulfone in the second stage was added to 258.5 g (0.9 mol), Na
The amount of S H・1.5Hto is 74.8g (0.9
Example 1 was carried out in the same manner as in Example 1, except that the amount of NMP was changed to 340 g (mol), and the amount of sodium hydroxide was changed to 36.0 g (0.9 mol), and the third step remained unchanged. The glass transition temperature of this polymer is 84°C and 209°C, and the melting point is 265°C.
The dynamic viscosity [η゛] measured at 316° C. and 10 rad/sec was 100 to 250 poise.

In addition, when we measured the infrared absorption spectrum of this polymer, no peaks other than the absorption of PPS, PP5S, and C-PP5 were observed, and from the strength of the characteristic absorption seen at 1690 cm''1 and the results of elemental analysis, it was found that the polymer PP inside
The molar ratio of S/PP5S/C-PP5 is 48.2:45.
It was confirmed that the ratio was 1:6.7. Furthermore, when this polymer was heat-treated at 2500C for 1 hour, it was heated to 316℃ and 10ra.
The dynamic viscosity [η'] measured by d/see is 250-4
It was 00 poise.

Example 3 The amount of p-dichlorobenzene in the first stage was 220. ．． 5
g (1.5 mol), N a S H・1. 5 H2
The amount of NMP is 1246 g (1.5 mol), the amount of NMP is 600 g, and the amount of sodium hydroxide is 60.0 g (1,5 mol).
5 mol), and the amount of 4,4'-dichlorodiphenylsulfone in the second stage was added to 86.2 g (0゜3+++ol
), the amount of Na S H-1, 5H20 is 24.9 g
(0.3 mol), the amount of NMP was changed to 140 g, and the amount of sodium hydroxide was changed to 12.0 g (0.3 mol), and the third step was carried out in the same manner as in Example 1. The glass transition points of this polymer are 83°C and 204°C, and the melting point is 2.
The dynamic viscosity [η'] measured at 316°C and 10 rad/sec was 200 to 300 poise. In addition, when we measured the infrared absorption spectrum of this polymer, no peaks other than the absorption of PPS, ppss, and C-PP5 were observed, and based on the intensity of the characteristic absorption seen at 1690 cm and the results of elemental analysis, it was found that the polymer The molar ratio of PPS/PP5S/C-PP5 in it is 77.2
:16,3:6.5. Furthermore, when this polymer was heat-treated at 250°C for 1 hour, it became 316°C and 1
The dynamic viscosity [η'] measured at 0 rad/see is 50
It was 0 to 700 poise.

Example 4 p-dichlorobenzene jlwo 205.8 in the first stage
g (1.4 mol), the amount of Na5H・1.5H20 is 1
163g (1.4mol), the amount of NMP is 570g and the amount of sodium hydroxide is 56.0g (1.4mol)
In addition, the amount of 2°4-dicobenzoic acid in the third stage was 19.1 g (0.1 mol), Na S H · 1.
The amount of 5Hxo was 8.3 g (0.1 mol), NM
The amount of P was 40g and the amount of sodium hydroxide was 8.0g (0
2moj) and the second step was carried out in the same manner as in Example 1. The glass transition point of this polymer is 85°
C and 208℃, the melting point is 272℃, 316℃, 10
Dynamic viscosity measured in rad/sec [η' is 200
It was ~300 poise.

Furthermore, when we measured the infrared absorption spectrum of this polymer, no peaks other than those of pps, PP5S, and C-PP5 were observed, and based on the intensity of the characteristic absorption seen at 1690 cm-' and the results of elemental analysis, we found that the polymer PP inside
The molar ratio of S/PP5S/C-PP5 is 70.5:25.
It was confirmed that the ratio was 3:4.2. Further, when this polymer was heat-treated at 250°C for 1 hour, it was heated to 316°C and 10ra.
Dynamic viscosity measured by d/see [η' is 450-6
It was 50 poise.

Example 5 The amount of p-dichlorobenzene in the first stage was 132.3 g.
(0.9 mol), N a S H・1. 5 H2O
The amount of 748 g (0.9 mol), the amount of NMP 400
g and the amount of sodium hydroxide to 36.0 g (0.9 mo
l), the amount of 4,4'-dichlorodiphenylsulfone in the second stage was 172.3 g (0.6 mol), Na
The amount of S H・1.5Hto is 49.9g (0.6m
ol), the amount of NMP to 240 g and the amount of sodium hydroxide to 24.0 g (0,6 mol), and the amount of 2,4-dichlorobenzoic acid in the third stage to 95.5 g (0,6 mol).
5 mol), the amount of N a S H 1.5 H, O was 41
．． The same procedure as in Example 1 was carried out except that the amount of NMP was changed to 200 g and the amount of sodium hydroxide was changed to 40.0 g (1.0 mol).

The glass transition point of this polymer was 82°C and 208°C, the melting point was 263°C, and the dynamic viscosity [η'] measured at 316°C and 10 rad/sec was 100 to 200 poise.

In addition, when we measured the infrared absorption spectrum of this polymer, no peaks other than the absorption of PPS, PP5S, and C-PP5 were observed, and from the strength of the characteristic absorption seen at 1690 cm-' and the results of elemental analysis, it was found that the polymer PP inside
The molar ratio of S/PP5S/C-PP5 is 50.8:34.
It was confirmed that the time was 9:15.3. When this polymer was further heat-treated at 250°C for 1 hour, the temperature at 316°C and 10 r
Dynamic viscosity measured in ad/sec [η' is 200~
It was 350 poise.

Example 6 In the first step, the amount of 4,4'-dichlorodiphenylsulfone was 258.5 g (0.9 mol), N a S H
・74.8g (0.9mol) of 1.5H20,
The amount of NMP was 400 g and the amount of sodium hydroxide was 36.
0 g (0.9 mol) to prepare reaction solution B, and
In the step, the amount of p-dichlorobenzene was 132.3g (0
, 9 mol), the amount of Na5H-1,5H20 was 74.8
Example 1 was carried out in the same manner as in Example 1, using 340 g (0.9 mol) of NMP and 36.0 g (0.9 mol) of sodium hydroxide, and leaving the third step unchanged.

The glass transition point of this polymer was 84°C and 211°C, the melting point was 263°C, and the dynamic viscosity [η'] measured at 316°C and 10 rad/sec was 100 to 250 poise.

In addition, when we measured the infrared absorption spectrum of this polymer, no peaks other than the absorption of PPS, PP5S, and C-PP5 were observed, and from the strength of the characteristic absorption seen at 1690 cm-' and the results of elemental analysis, it was found that the polymer PP inside
The molar ratio of S/PP5S/C-PP5 is 47.2:46.
It was confirmed that the ratio was 2:6.6. Furthermore, when this polymer was heat-treated at 250°C for 1 hour, it was heated to 316°C and 10ra.
The dynamic viscosity [η'] measured in d/sec is 250-4
It was 50 poise.

Example 7 In the first step, 95.5 g of 2,4-dichlorobenzoic acid (
0.50 mol), N a S H・1.5 Hso
41.1g (0,5+nol), 240g NMP
and 40゜0g (1.0mol) of sodium hydroxide
In the second step, the amount of p-dichlorobenzene was 132.3 g (0.9 mol), Na
S H・1. 5 The amount of H2O is 74.8g (0,9
mol), the amount of NMP was 340 g and the amount of sodium hydroxide was 36.0 g (0.9 mol), and the amount of 4,4'-dichlorodiphenylsulfone in the third stage was 17
2.3g (0.6mol), NaSH・1.5
The amount of H20 was 49.9 g (0.6 mol), the amount of NMP was 240 g, and the amount of sodium hydroxide was 24.0 g (0.6 mol).
, 6 mol) in the same manner as in Example 1.

The glass transition points of this polymer were 83°C and 209°C, the melting point was 265°C, and the dynamic viscosity [η'] measured at 3-16°C and 10 rad/see was 100-250 poise.

In addition, when we measured the infrared absorption spectrum of this polymer, no peaks other than the absorption of PPS, ppss, and c-pps were observed, and based on the intensity of the characteristic absorption seen at 1690 cm-' and the results of elemental analysis, it was found that the polymer PP inside
The molar ratio of S/PP5S/C-PP5 is 49.8:35.
It was confirmed that the time was 4:14.8. Furthermore, when this polymer was heat-treated at 250°C for 1 hour, it was heated to 316°C and 10ra.
The dynamic viscosity [η'] measured in d/sec is 200 to 4
It was 00 poise.

Example 8 The same procedure as in Example 1 was carried out using equimolar amounts of sodium sulfide pentahydrate instead of the combination of Na SH·1.5H,0 and sodium hydroxide. The glass transition point of this polymer is 82°C and 207°C, and the melting point is 269°C and 316°C.
, the dynamic viscosity [η'] measured at 10 rad/sec was 100 to 250 poise.

In addition, when we measured the infrared absorption spectrum of this polymer, no peaks other than those of pps, PP5S, and c-pps were observed, and based on the intensity of the characteristic absorption seen at 1690 cm-' and the results of elemental analysis, we found that the polymer PP inside
The molar ratio of S/PP5S/C-Pps was 68.0:25.
It was confirmed that the ratio was 3:6.7. When this polymer was further heat-treated at 250°C for 1 hour, it was heated to 316°C and 10 ra.
The dynamic viscosity [η'] measured in d/sec is 350-5
It was 50 poise.

Example 9 Reaction solution A (p-dichlorobenzene (13IIlo1) prepared in the same manner as in Examples 1, 6 and 7)
22
The reaction was carried out at 0°C for 5 hours and then at 240°C for 2 hours under a nitrogen atmosphere. The glass transition temperature of this polymer is 82℃ and 20℃.
9℃, melting point is 271'C, 316℃, 10ra
Dynamic viscosity measured by d/see [η' is 200 to 3
It was 00 poise.

Furthermore, when we measured the infrared absorption spectrum of this polymer, no peaks other than those of pps, PP5S, and C-PP5 were observed, and based on the intensity of the characteristic absorption seen at 1690 cm-' and the results of elemental analysis, we found that the polymer PP inside
The molar ratio of S/PP5S/C-Pps is 68.1:25.
It was confirmed that the ratio was 1:6.8. Furthermore, when this polymer was heat-treated at 250°C for 1 hour, it was heated to 316°C and 10ra.
The dynamic viscosity η' measured in d/sec is 400 to 6
It was 00 poise.

(Effects of the invention) The block copolymer of the present invention has excellent heat resistance, moldability, dimensional stability, etc., and also has good adhesion, adhesion, and compatibility with other resins and/or inorganic fillers. It is possible to produce the block copolymer very easily, efficiently, and stably.

Claims (1)

[Claims] 1. Consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
An arylene sulfide block copolymer having a molecular weight in the range of ~10^5 poise. 2, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
In a method for producing an arylene sulfide block copolymer having a polyphenylene sulfide prepolymer in the range of ~10^5 poise, in a polar solvent in which a polyphenylene sulfide prepolymer is present,
A method for producing a block copolymer, which comprises reacting a dihalogeno aromatic sulfone with a sulfidating agent, and then reacting a dihalogeno aromatic carboxylic acid and/or an alkali metal salt thereof with the sulfidating agent. 3, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
In a method for producing an arylene sulfide block copolymer having a polyphenylene sulfide prepolymer in the range of ~10^5 poise, in a polar solvent in which a polyphenylene sulfide prepolymer is present,
A method for producing a block copolymer, which comprises reacting a dihalogeno aromatic carboxylic acid and/or an alkali metal salt thereof with a sulfidating agent, and then reacting a dihalogeno aromatic sulfone with a sulfidating agent. 4, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
In a method for producing an arylene sulfide block copolymer having a polyphenylene sulfide sulfone prepolymer in the range of ~10^5 poise, dihalobenzene and a sulfidating agent are reacted in a polar solvent in which a polyphenylene sulfide sulfone prepolymer is present;
A method for producing a block copolymer, which comprises then reacting a dihalogeno aromatic carboxylic acid and/or an alkali metal salt thereof with a sulfidating agent. 5, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
In a method for producing an arylene sulfide block copolymer having a molecular weight in the range of ~10^5 poise, sulfidation is performed with a dihalogeno aromatic carboxylic acid and/or an alkali metal salt thereof in a polar solvent in which a polyphenylene sulfide sulfone prepolymer is present. 1. A method for producing a block copolymer, which comprises reacting a dihalobenzene with a sulfiding agent, and then reacting a dihalobenzene with a sulfidating agent. 6, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
In a method for producing an arylene sulfide block copolymer having a molecular weight in the range of ~10^5 poise, sulfidation is performed with dihalobenzene in a polar solvent in the presence of a polyphenylene sulfide prepolymer or a polyphenylene sulfide sulfone prepolymer containing a carboxyl group. 1. A method for producing a block copolymer, which comprises reacting a dihalogeno aromatic sulfone with a sulfidating agent. 7, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide or polyphenylene sulfide sulfone moiety containing a carboxyl group, 316 ° C.
Dynamic viscosity [η'] at 10 rad/sec is 10 to 1
In a method for producing a block copolymer having a poise range of 0^5, a dihalogeno aromatic sulfone and a sulfidating agent are reacted in a polar solvent in which polyphenylene sulfide or polyphenylene sulfide sulfone prepolymer containing a carboxyl group is present. , and then reacting dihalobenzene with a sulfidating agent. 8, consisting of (A) a polyphenylene sulfide moiety, (B) a polyphenylene sulfide sulfone moiety, and (C) a polyphenylene sulfide moiety containing a carboxyl group or the same polyphenylene sulfide sulfone moiety, 316
℃, dynamic viscosity [η'] at 10 rad/sec is 10
In a method for producing an arylene sulfide-based block copolymer having a molecular weight in the range of ~10^5 poise, a polyphenylene sulfide prepolymer, a polyphenylene sulfide sulfone prepolymer, and a carboxyl group-containing polyphenylene sulfide prepolymer or the polyphenylene sulfide are mixed in a polar solvent. A method for producing a block copolymer, which comprises reacting a block copolymer with a sulfone prepolymer.