JPH03152122A - Production of conjugate system polymer - Google Patents

Abstract

PURPOSE:To obtain the subject polymer capable of providing films having high electric conductivity, high strength and elasticity, by copolymerizing respective specific plural monomers and subjecting the resultant precursor to removal treatment of a sulfonium salt in an inert atmosphere. CONSTITUTION:The objective polymer obtained by copolymerizing a bifunctional monomer expressed by formula I [R1 is a group capable of forming a C-C conjugate system continuous to -CH=CH-; G' is formula II or III (R2 and R3 are 1-20C hydrocarbon; R4 is 4-20C bifunctional hydrocarbon); X1<-> is counter ion] with a tri- or polyfunctional monomer expressed by formula IV [R5 is a group capable of forming a C-C conjugate system continuous to -CH=CH-; G'' is formula V or VI (R6 and R7 are 1-20C hydrocarbon; R8 is 4-20C bifunctional hydrocarbon); X2<-> is counter ion; n is >=3] and subjecting the resultant conjugate system polymer precursor to removing treatment of a sulfonium salt in an inert atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a conjugated polymer having high electrical conductivity. This polymer is useful as a conductive polymer.

<Prior Art> The conjugated polymer obtained by the present invention has a structure crosslinked by conjugated chains. Many conjugated polymers have been known so far, such as polyacetylene, poly-p-)unilene, polythiophene, polypyrrole, poly-roof unilene vinylene, and poly-2,5-chenylene vinylene. Furthermore, many methods for producing these materials have been investigated, and methods such as catalytic polymerization, electrochemical polymerization, and methods via soluble polymer intermediates have been reported. As a method of obtaining a conjugated polymer exhibiting high conductivity, a method of reducing defects in the conjugated chain,
A method for highly orienting conjugated molecules has been proposed. Also,
Although it is known to copolymerize two or more monomers, no improvement in electrical conductivity (hereinafter referred to as type conductivity) has been observed by copolymerization.

Furthermore, polydiacetylene bonded with urethane groups is also known as a conjugated polymer crosslinked for the purpose of improving the mechanical strength of the conjugated polymer.

<Problems to be solved by the invention> However, in the conductive polymers known so far, the temperature dependence of conductivity is semiconductor-like, and it is said that intermolecular conduction of carriers is rate-determining. . In order to improve conductivity, intermolecular conduction must be reduced as much as possible. In this respect, since graphite has a structure in which the conjugated system is two-dimensionally spread, it is less affected by intermolecular conduction and has high electrical conductivity.

As described above, there has been a need for conjugated polymers that are less affected by intermolecular conduction.

An object of the present invention is to provide a method for producing a three-dimensionally crosslinked conjugated polymer capable of carrier conduction.

Means for Solving the Problems> The present invention is based on the general formula (1) %Formula %(1) R, groups Rx, Rs that form a continuous carbon-carbon conjugated system with CH=CH-: carbon number 1 ~20 hydrocarbon groups, R1: trifunctional hydrocarbon group having 4 to 20 carbon atoms X1-: bifunctional monomer represented by a counter ion, and general formula (2)% formula%
) (2) R6: group forming a continuous carbon-carbon conjugated system with -CH=C-, Rt: hydrocarbon group having 1 to 20 carbon atoms, R8: trifunctional hydrocarbon having 4 to 20 carbon atoms group, X2-2 counterion, n: an integer of 3 or more, and a conjugated polymer precursor obtained by copolymerizing with a trifunctional or more functional monomer represented by A method for producing a characteristic conjugated polymer is provided.

The present invention will be explained in detail below.

The monomer used in the present invention is a bissulfonium salt having a group forming a continuous carbon-carbon conjugated system with one CH=CH- shown in the above general formula (1), and a bissulfonium salt shown in the above general formula (2). 1C) It has three or more sulfonium bases having a group forming a continuous carbon-carbon conjugated system with 1=cH-. In the above general formula (1), R is -C
A group that forms a continuous carbon-carbon conjugated system with H=CH-, and is an aromatic hydrocarbon having 6 to 14 carbon atoms and its nuclear substituted product, or a heterocyclic aromatic compound having 4 to 13 carbon atoms and its nucleus. It is a substitute. These substituents are not particularly limited, but include hydrocarbon groups having 1 to 10 carbon atoms, and 1 to 10 carbon atoms.
An alkoxy group is preferred. R1 group is p-phenylene,
2,5-Simethoxy-p-phenylene, 2,5-jethoxy-p-phenylene, 2,5-dimethyl-p-phenylene, 2,6-naphthalenediyl, 2,5-thhenylene, 3-methyl-2,5- Chenylene, 3-methoxy-2
, 5-chenylene, 2,5-furandiyl and the like. Particularly preferred are p-phenylene and 2,5-chenylene. R,, R, is a hydrocarbon group having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, 2-ethylhexyl, phenyl, cyclohexyl, benzyl group, etc., and has 1 to 6 carbon atoms. Hydrocarbon groups, particularly methyl and ethyl groups, are preferred. R1 is a trifunctional hydrocarbon group having 4 to 10 carbon atoms, such as tetramethylene, pentamethylene, hexamethylene group, etc., but hydrocarbon groups having 4 to 6 carbon atoms, particularly tetramethylene and hexamethylene groups are preferable. .

Any counter ion Xl- of the sulfonium salt can be used in a conventional manner. For example, halogen, hydroxyl, boron tetrafluoride, perchloric acid, carboxylic acid, sulfonate ions, etc. can be used, and among them, halogen ions such as chlorine, bromine, and iodine are preferred.

The monomer represented by the above general formula (2) functions as a crosslinking agent. R6 is a group forming a continuous carbon-carbon conjugated system with -CH=C)l-, and is an aromatic hydrocarbon having 6 to 14 carbon atoms and its nuclear substituted product, or a heterocyclic ring having 4 to 13 carbon atoms. These are aromatic compounds and their nuclear substituted products.

There are no particular limitations on these substituents, but those with a carbon number of 1-
A 10 hydrocarbon group and an alkoxy group having 1 to 10 carbon atoms are preferred. R6 group is benzenetriyl, benzenetetryl, 2-methoxy-benzenetriyl, 2-ethoxy-
Examples include benzenetriyl, 2-methyl-benzentriyl, naphthalenetriyl, naphthalenetetrayl and the like. Particularly preferred is benzenetetryl. R6 and R7 are hydrocarbon groups having 1 to 10 carbon atoms, such as methyl, ethyl,
Examples include propyl, isopropyl, n-butyl, 2-ethylhexyl, phenyl, cyclohexyl, and benzyl groups, and hydrocarbon groups having 1 to 6 carbon atoms, particularly methyl and ethyl groups, are preferred. R8 is a trifunctional hydrocarbon group having 4 to 10 carbon atoms, such as tetramethylene, pentamethylene, hexamethylene group, etc., but hydrocarbon groups having 4 to 6 carbon atoms, particularly tetramethylene and hexamethylene groups are preferable. .

Sulfonium salt counterion X! - can be arbitrarily used in a conventional manner. For example, halogen, hydroxyl, boron tetrafluoride, perchloric acid, carboxylic acid, sulfonate ions, etc. can be used, and among them, halogen ions such as chlorine, bromine, and iodine are preferred.

The polymer intermediate is prepared by combining the bissulfonium salt shown in the above general formula (1) and the polysulfonium salt shown in the above general formula (2) in water alone or in a water-soluble organic solvent such as an alcohol. It can be obtained by condensation polymerization using an alkali in a mixed solvent of

Preferably, it is effective to polymerize in water alone or in a mixed solvent of water and an alcohol soluble therein.

The addition ratio of the bissulfonium salt shown in the above general formula (1) and the polysulfonium salt shown in the above general formula (2) can be selected at any ratio, but depending on the polymerization rate of both and the functionality of the above general formula (2), It is preferable to select the ratio appropriately in consideration of the number of groups. For example, the polysulfonium salt shown in the above general formula (2)! If the number of bonds is too large, it will be extremely crosslinked and become insolubilized, which is not preferable in terms of formability. On the other hand, if the amount is too small, the crosslinking effect will not appear, which is not preferable. The molar ratio of the above monomer (1) and crosslinking agent (2) used is l:l
From 1:0. O05, preferably 1:0.1 to 1:
It is in the range of 0.01.

The bissulfonium salt shown in the above general formula (1) and the polysulfonium salt shown in the above general formula (2) may be added at any time, but depending on the polymerization rate and addition ratio of both. It is preferable to select the addition timing appropriately in consideration of the following. Both may be polymerized by adding them from the beginning, or if the polymerization rate of the polysulfonium salt shown in the above general formula (2) alone is fast, the polymerization of the bissulfonium salt shown in the above general formula (1) may be carried out to some extent. It is effective to add the polysulfonium salt of the above general formula (2) at the point when the process has proceeded.

The alkaline solution used for condensation polymerization is preferably an organic solvent that does not react with water or monomers, such as a strongly basic solvent with a pH of 11 or higher in a mixed solvent of alcohols and water, such as sodium hydroxide, potassium hydroxide, hydroxide, etc. Calcium, quaternary ammonium salt hydroxide, sulfonium salt hydroxide, strongly basic ion exchange resin (OH type), etc. can be used, but sodium hydroxide 1. Potassium hydroxide can be preferably used.

The condensation polymerization reaction is preferably carried out at a relatively low temperature, ie at a temperature of at least 50°C or lower, particularly at a temperature of 25°C or lower. The reaction time is not particularly limited, but is usually 1 minute to 100 minutes.
It is a range of time.

According to the method of the invention, the polymeric intermediate is soluble;
Obtained as a high molecular weight polymer electrolyte (polymer sulfonium salt) having a sulfonium salt in its side chain. Furthermore, the resulting polymer intermediate may be modified to have a structure in which the sulfonium salt side chain is substituted with a nucleophilic substituent. For example, an alcohol used as a polymerization solvent can be reacted to form an intermediate in which an alkoxy group becomes a side chain and is soluble in an organic solvent. The intermediate is sensitive to heat, light, ultraviolet light, strong base or acidic conditions, etc., and side chains are gradually eliminated.

A feature of the present invention is that a molded article of any shape can be made from a polymer intermediate, especially a solution thereof. Any method can be used to obtain the polymer molded article. Regarding its form, it can be formed into, for example, a film, fiber, coating film, or any other form. Particularly useful forming methods are polymeric sulfonium salts, water or alcohol alone,
Alternatively, a method using a mixed solution with an organic solvent soluble in water or alcohol, such as acetone, or a solution in which a sulfonium salt side chain substituted with a nucleophilic substituent is dissolved in an organic solvent, such as a method using the above general formula ( This method uses an N,N-dimethylformamide solution of a polymer intermediate in which the side chain is substituted with a methoxy group when R in 1) is thiophene. This method involves forming a film by casting, forming fibers by solution spinning, and applying a solution to a substrate.

At this time, it is preferable to use a polymer intermediate solution that has been desalted or unreacted substances removed by dialysis treatment, reprecipitation treatment, etc. in advance.

A three-dimensional conjugated polymer crosslinked with a conjugated system can be produced by post-processing the polymer intermediate. The post-treatment of the polymer intermediate referred to here involves the removal of sulfonium salt side chains or side chains substituted with nucleophilic substituents by applying conditions such as heat, light, ultraviolet light, strong base or acid treatment, etc. , which means forming a conjugated structure, and heat treatment is particularly preferred. Further, the treatment of the polymer intermediate is preferably performed in an inert atmosphere.

The inert atmosphere here refers to an atmosphere that does not cause oxidation or other changes in the polymer during processing, and is generally carried out using an inert gas such as nitrogen, argon, helium, etc. You can also do this inside.

When post-processing a polymer intermediate using heat, heat treatment at too high a temperature will result in the decomposition of the resulting conjugated polymer, and at low temperatures the reaction is slow and impractical, so the treatment temperature is usually 0°C. ~450°C, preferably 100°C ~38
0°C is suitable. Further, the treatment time can be appropriately selected depending on the treatment temperature, but a range of 1 minute to 10 hours is industrially practical.

The conjugated polymer thus produced can also be heat-treated by stretching and orienting a molded product of the polymer intermediate.

These stretching and orientation treatments are performed before processing the polymer intermediate.
Or they can be done at the same time. Orientation can be achieved by devising a molding method, such as extrusion using high shear force, but high orientation can be imparted by stretching and heating a polymer intermediate molded product from a polymer intermediate solution. .

When the conjugated polymer obtained by the present invention is reacted (doped) with known electron-donating or electron-accepting molecules or atoms, conductivity is developed.

The conjugated polymer film obtained by the present invention exhibits excellent mechanical properties such as high strength and high elasticity.

<Effects of the Invention> As explained above, according to the present invention, a three-dimensional conjugated polymer crosslinked with a high molecular weight conjugated system can be obtained, and the present invention can be applied to electrical and electronic materials. Conjugated polymers having various shapes are provided.

<Example> The present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way Example 1 1,2.4.5-tetrakis(bromomethyl)benzene and tetrahydrothiophene A solution obtained by dissolving 0.8 g of a tetrafunctional sulfonium salt monomer obtained by reacting with 7 g of p-xylylene bis(tetramethylene sulfonium chloride) in 100 ml of ion-exchanged water was water-cooled to 0 to 5°C, and then heated with nitrogen. The inside of the system was replaced with nitrogen by bubbling. This solution was cooled and replaced with nitrogen in the same way.
61 ml of 35N sodium hydroxide solution was added dropwise over about 90 minutes. After the dropwise addition, polymerization was continued for 2 hours at 0 to 5°C, and a gel-like precipitate was produced. The polymerization solution was neutralized and the generated precipitate was collected. This precipitate was soluble in methanol. This solution was cast and dried in a nitrogen stream to obtain a pale yellow conjugated polymer intermediate film.

This intermediate film (length 2 cm, width 3 cm) was stretched to 6.5 times in a nitrogen stream using a horizontal tube furnace.
Heat treatment was performed at 0° C. for 2 hours to obtain a stretched conjugated polymer film. Infrared dichroism (1520c) of this film
m-') was 18.6.

Reference Example 1 The stretched film obtained in Example 1 was treated with H2SO4, which is an electron acceptor compound, by a conventional method at room temperature)1. S.O.

When doping inside, 3.0 xlo3s
/ cm. The electrical conductivity was measured using a four-terminal method.

Example 2 Ion exchange of 0.32 g of a tetrafunctional sulfonium salt monomer obtained by reacting 1,2.4.5-tetrakis(bromomethyl)benzene with tetrahydrothiophene and 7 g of p-xylylene bis(tetramethylenesulfonium chloride) After the solution dissolved in water room 1 was ice-cooled to 0 to 5°C, the inside of the system was replaced with nitrogen by nitrogen bubbling. This solution was cooled and replaced with nitrogen in the same way.
61 ml of 35N sodium hydroxide solution was added dropwise over about 90 minutes. After the dropwise addition, polymerization was continued for 2 hours at 0 to 5°C, and a gel-like precipitate was produced. The polymerization solution was neutralized, a large amount of acetone was added, and the resulting precipitate was collected. This precipitate was soluble in methanol. This solution was cast and dried in a nitrogen stream to obtain a pale yellow conjugated polymer intermediate film. This intermediate film (length 2 cm, width 3 cm) was stretched to 7.6 times in a nitrogen stream using a horizontal tubular furnace, and heat treated at 370°C for 2 hours to obtain a stretched conjugated polymer film. Ta. The infrared dichroism (1520 cr') of this film was 33.9.

Reference Example 2 The stretched film obtained in Example 2 contained an electron acceptor compound) l! Using SO, H,SO at room temperature in a conventional manner.

When doping inside, 6,6 X10'S
It showed an electrical conductivity of /cm. The electrical conductivity was measured using a four-terminal method.

Example 3 A solution in which 7 g of p-xylylene bis(tetramethylene sulfonium chloride) was dissolved in 100 ml of ion-exchanged water was water-cooled to 0 to 5°C, and then the system was replaced with nitrogen by nitrogen bubbling. To this solution, 61 ml of 0.35N sodium hydroxide solution was cooled and replaced with nitrogen in the same way.
was added dropwise over about 90 minutes.

After the dropwise addition, polymerization was continued for 2 hours at θ to 5°C, and a gel-like precipitate was produced. Add 25 methanol to this polymerization solution.
After adding m1 to make a homogeneous solution, add 1.2.4.5 to this.
A solution obtained by dissolving 0.32 g of a tetrafunctional sulfonium salt monomer obtained by reacting -tetrakis(bromomethyl)benzene and tetrahydrothiophene in 10 ml of ion-exchanged water was added. Subsequently, polymerization was carried out at 0 to 5°C for 2 hours. The polymerization solution was neutralized, a large amount of acetone was added, and the resulting precipitate was collected. This precipitate was cast from this methanol-soluble solution and dried in a nitrogen stream to obtain a pale yellow conjugated polymer intermediate film.

This intermediate film (length 2 cm, width 3 cm) was stretched to 6.0 times in a nitrogen stream using a horizontal tube furnace, and
C. for 2 hours to obtain a stretched conjugated polymer film. Infrared dichroism of this film (1520c+
n-') was 30.2.

Reference Example 3 Using H2SO, which is an electron acceptor compound, the stretched film obtained in Example 3 was exposed to H2SO at room temperature by a conventional method.

When doping inside, 5.2X10'S/
It showed a conductivity of cm. The electrical conductivity was measured using a four-terminal method.

Example 4 1.4 g of a tetrafunctional sulfonium salt monomer obtained by reacting 1,2.4.5-tetrakis(bromomethyl)benzene with tetrahydrothiophene and 7 g of p-xylylene bis(tetramethylenesulfonium chloride) were ionized. After the solution dissolved in 120 ml of exchanged water was water-cooled to 0 to 5°C, the inside of the system was replaced with nitrogen by nitrogen bubbling.

This solution was cooled and replaced with nitrogen in the same way.
61 ml of 5N sodium hydroxide solution was added dropwise over about 90 minutes. After the dropwise addition, polymerization was continued for 2 hours at 0 to 5°C, and a gel-like precipitate was produced. The polymerization solution was neutralized, a large amount of acetone was added, and the resulting precipitate was collected.

This precipitate was soluble in methanol. This solution was cast and dried in a nitrogen stream to obtain a pale yellow conjugated polymer intermediate film. This intermediate film was heat-treated at 370° C. for 12 hours in a nitrogen stream using a horizontal tubular furnace to obtain a conjugated polymer film.

Reference Example 4 H2, which is an electron acceptor compound, was added to the film obtained in Example 4.
When doping in H, SO, was carried out at room temperature using a conventional method, 1.6 x 102S/
It showed a conductivity of cm. The electrical conductivity was measured using a four-terminal method.

Example 5 2.0 g of a tetrafunctional sulfonium salt monomer obtained by reacting 1,2.4.5-tetrakis(bromomethyl)benzene with tetrahydrothiophene and 2,5-chenylenebis(methylenedimethylsulfonium bromide) 15
g and ion exchange water 260ml/methanol 260ml
After cooling the solution dissolved in the solution to -40 to -30'C, the inside of the system was replaced with nitrogen by nitrogen bubbling. To this solution, add about 40 ml of a mixed solution of 21 ml of 1N sodium hydroxide aqueous solution / 160 ml of methanol, which was cooled with water and replaced with nitrogen.
It was dripped over several minutes. After dropping, polymerization was continued at -40 to -30°C for 1.5 hours.

After neutralizing the polymerization solution, it was dialyzed in a mixed solvent of methanol/water = 110.15 at an ice-cooled temperature for 1 day. Next, the generated precipitate was filtered and collected, briefly washed with methanol, and then dissolved in N,N-dimethylformamide (DMF). This was filtered through a Millipore filter to obtain a DMF solution of the conjugated polymer intermediate. This solution was cast and dried in a nitrogen stream to obtain a pale yellow conjugated polymer intermediate film. Next, this film was heat-treated at 250° C. for 2 hours in a nitrogen stream to obtain a conjugated polymer film.

Reference Example 5 I2, an electron acceptor compound, was added to the film obtained in Example 5.
When doping was carried out in the gas phase at room temperature using a conventional method, it showed an electrical conductivity of 3.5×10 2 S/cm. The electrical conductivity was measured using a four-terminal method.

Comparative Example 1 A solution in which 7 g of p-xylylene bis(tetramethylenesulfonium chloride) was dissolved in 100 mA' of ion-exchanged water was ice-cooled to 0 to 5°C, and then the system was replaced with nitrogen by nitrogen bubbling. To this solution, 61ml of 0.35N sodium hydroxide solution was cooled and replaced with nitrogen in the same way.
1 was added dropwise over about 90 minutes.

After the dropwise addition, polymerization was continued for 2 hours at 0 to 5°C, and a gel-like precipitate was produced. The polymerization solution was neutralized, a large amount of acetone was added, and the resulting precipitate was collected. This precipitate was soluble in methanol. Cast from this solution,
It was dried in a nitrogen stream to obtain a pale yellow conjugated polymer intermediate film. This intermediate film (length 2cm, width 3cm)
m) was stretched to 7.8 times in a nitrogen stream using a horizontal tubular furnace, and heat treated at 370°C for 2 hours to obtain a stretched conjugated polymer film. The infrared dichroism of this film (
1520cr') was 30.0. Using HlSO, which is an electron acceptor compound, in this stretched film,
When doping was carried out in HlSO at room temperature by a conventional method, 4. The conductivity was 1X10"S/cm. The conductivity was measured by the four-terminal method.

Comparative Example 2 8.2 g of a tetrafunctional sulfonium salt monomer obtained by reacting 1,2.4.5-tetrakis(bromomethyl)benzene and dimethyl sulfide was added to 70 ml of ion-exchanged water.
After cooling the solution dissolved in 1 with water to 0 to 5°C, the inside of the system was purged with nitrogen by nitrogen bubbling.

This solution was cooled and replaced with nitrogen in the same way.
75 ml of 3N sodium hydroxide solution was added dropwise over about 30 minutes. A yellow precipitate was formed during the dropwise addition. After dropping, polymerization was continued for 0.5 hours at 0 to 5°C. The polymerization solution was neutral. A precipitate was collected, but this precipitate was insoluble. This precipitate was heat-treated at 370° C. for 1 hour in a nitrogen stream using a horizontal tubular furnace, and a black powder was obtained.

Claims (1)

[Claims] General formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R_1: A group forming a continuous carbon-carbon conjugated system with -CH=CH- ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Numerical formula , chemical formulas, tables, etc. ▼ R_2, R_3: Hydrocarbon group with 1 to 20 carbon atoms, R_4
: Difunctional hydrocarbon group having 4 to 20 carbon atoms Groups forming a carbon-carbon conjugated system ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ R_6, R_7: Hydrocarbon group with 1 to 20 carbon atoms, R_8
: Difunctional hydrocarbon group having 4 to 20 carbon atoms A method for producing a conjugated polymer characterized by desulfonium salt treatment in an atmosphere