JPH09302073A - Multibranched polymer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multibranched polymer which can be doped with cations by producing a Grignard reagent of a compd. represented by a specific formula and polymerizing the reagent by the Grignard reaction. SOLUTION: An intermediate is produced by suspending a triazine compd. represented by formula I (wherein X is Br, Cl, or I) in a solvent (e.g. tetrahydrofuran) in a reactor, cooling the resultant suspension under stirring, and adding a soln. of n-butyllithium in hexane to the suspension to react the triazine compd. with n-butyllithium. A Grignard reagent represented by formula II is produced by dropping a soln. of a magnesium halide etherate in diethyl ether into the intermediate to react the etherate with the intermediate. A multibranched polymer having repeating units represented by formula III is obtd. by dropping the reagent into a soln. of Ni acetylacetonate in tetrahydrofuran, elevating the temp. of the soln. under stirring, and allowing the reagent and Ni acetylacetonate to react. Voltage is applied between a platinum electrode coated with a layer of the multibranched polymer and a counter electrode in an electrolyte soln. to dope the layer with cations in the soln.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a hyperbranched polymer (dendrimer) and a method for producing the same, and more particularly to a hyperbranched polymer capable of reversibly doping with cations and a method for producing the same.

[0002]

2. Description of the Related Art Generally, a π-conjugated polymer material containing π-electrons often exhibits conductivity and electricity storage. In addition, it is often doped with ions to show a charge storage property.
Further, a π-conjugated polymer material that exhibits an electricity storage property by being doped with ions often exhibits an electrochromic property in which a color changes with the doping of ions. Such π-conjugated polymer materials are expected to be applied to devices in the fields of electronics and optoelectronics.

For example, a material that reversibly moves ions in and out is expected to be used as an electrode material for batteries. Polyacene is already used as a material for coin-type primary batteries. Polyaniline is 2,5-dimercapto-1,
It can be mixed with 3,4-thiadiazole to form a positive electrode, and L
Research is under way to create batteries in combination with i-metal negative electrodes.

By the way, many polymer materials capable of doping ions have been reported so far, but most of them have been capable of doping anions. There are few types of π-conjugated polymer materials that can be doped with cations, and they lack versatility as polymer materials.

[0005]

An object of the present invention is to provide a novel hyperbranched polymer which can be doped with cations, a method for producing the same, and the like.

Another object of the present invention is to provide a novel hyperbranched polymer having electrochromic properties by cation doping, a method for producing the same, and the like.

[0007]

According to one aspect of the present invention, a general formula

[0008]

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There is provided a hyperbranched polymer having a repeating unit represented by: According to another aspect of the invention, a general formula

[0010]

[Chemical 6]

From the compound represented by the general formula

[0012]

[Chemical 7]

A method for producing a hyperbranched polymer is provided, which comprises a step of producing a Grignard reagent represented by and a step of polymerizing the Grignard reagent by a Grignard reaction.

The hyperbranched polymer containing the triazine ring is
It can be doped with cations. Examples of the cation include alkali metal ions such as Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , Sc ⁺ , H ₄ N ⁺ , Me (methyl) ₄ N ⁺ , Et.
A quaternary alkylammonium ion such as (ethyl) ₄ N ⁺ and (n-Bu (butyl)) ₄ N ⁺ can be used. Doping with these cations can be performed by an electrochemical method, a chemical method, or the like.

The multi-branched polymer changes color from white to red or brown with cation doping, and returns to white by dedoping. By utilizing such electrochromic phenomenon, it can be used as an electrochromic display material. Further, it can be used as a charge / discharge material for electrodes of batteries by utilizing the property of reversibly doping and dedoping cations.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present inventors

[0017]

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A hyperbranched polymer having a repeating unit represented by the following formula was successfully produced. Hereinafter, a method for producing the hyperbranched polymer will be described. First, the general formula

[0019]

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A compound represented by the formula: This manufacturing method is described in US Pat. No. 3,932,402. When an alkyllithium reagent is allowed to act on this hyperbranched polymer,

[0021]

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An intermediate compound represented by: This intermediate compound is further reacted with magnesium halide etherate to give a compound of the general formula

[0023]

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A Grignard reagent represented by the following formula is obtained. This Grignard reagent is Grignard polymerized in the presence of a nickel catalyst to obtain the desired multibranched polymer.

Alkyllithium reagents include MeL
i, EtLi, n-BuLi, sec-BuLi, or the like can be used. As the reaction solvent, tetrahydrofuran, diethyl ether, dibutyl ether, anisole, and other ether solvents can be used. Since the Grignard reagent reacts violently with water vapor and oxygen in the atmosphere, all reactions are performed in an inert gas atmosphere to avoid side reactions with oxygen and moisture.

General formula

[0027]

[Chemical 12]

The hyperbranched polymer having a repeating unit represented by the formula (1) can be doped with a cation as described above. In the case of electrochemically doping with cations, a multibranched polymer is supported on the electrode surface, and this electrode is immersed together with the counter electrode in an electrolytic solution in which a neutral supporting electrolyte is dissolved. By appropriately controlling the applied voltage or current between the electrodes, the ions can be reversibly attached and detached.

As the electrode for supporting the multi-branched polymer,
Platinum, gold, carbon, indium-tin oxide, etc. can be mentioned. Examples of the supporting electrolyte include alkyl tetrafluoroborate alkylammonium salts such as tetra-n-butylammonium tetrafluoroborate, tetrafluoroborate alkali metal salts such as lithium tetrafluoroborate,
Such as alkylammonium perchlorate salts such as tetraethylammonium perchlorate, alkali metal perchlorate salts such as lithium perchlorate, alkylammonium hexafluorophosphate salts such as tetra-n-butylammonium hexafluorophosphate, sodium hexafluorophosphate, etc. Examples thereof include alkali metal hexafluorophosphate salts, alkylammonium p-toluenesulfonate salts such as tetramethylammonium p-toluenesulfonate, and alkali metal trifluoroacetate salts such as sodium trifluoroacetate.

Examples of the solvent include acetonitrile, propylene carbonate, nitromethane, sulfolane, N-methylpyrrolidone and the like. Hereinafter, description will be given according to a specific example of producing a multibranched polymer.

First, 2,4, which is a raw material of the hyperbranched polymer,
The method for producing 6-tris (p-bromophenyl) -1,3,5-triazine will be described. This method follows the synthetic method described in US Pat. No. 3,932,402.

While stirring 1.97 g (10.8 mmol) of p-bromobenzonitrile set aside in the flask, 5.50 g (36.
6 mmol) was added dropwise from a dropping funnel and added. The reaction system was kept between 0 ° C and 10 ° C by an ice water bath. After the addition was completed, bring the reaction system to room temperature, stop stirring, and
Let stand for 8 hours.

Next, the orange reaction solution was dropped onto ice and the acidic aqueous solution containing a white precipitate obtained after the ice was thawed was neutralized with aqueous ammonia. The precipitate was collected by filtration and washed with 70 ml of 1: 1 acetone-dichloromethane. Further, the precipitate was recrystallized from benzene and vacuum dried at 60 ° C. for 2 hours. The amount was 1.59 g (81%). The product is white needle crystals, melting point 367 ° C-370.
° C.

FIG. 1 shows the infrared absorption spectrum of the product obtained. 222 due to the nitrile group contained in the raw material
The absorption at 5 cm ^-1 disappeared, indicating that the raw materials had fully reacted. On the other hand, 1580, 1515, 1402, 13
Around 71 cm ⁻¹ , many strong absorptions can be observed compared to the raw material. It is considered that this is due to the C = C stretching vibration of the benzene ring and the C = N stretching vibration of the newly generated triazine ring.

The absorptions at 1172, 1068 and 1011 cm ^-1 are attributed to the C-H in-plane bending vibration of the benzene ring.
The absorptions at 843 and 807 cm ^-1 are attributed to C-H out-of-plane bending vibration. The absorptions at 496 and 476 cm ^-1 are C-
It is considered to be due to Br stretching vibration.

FIG. 2 shows the general formula believed to be the chemical composition of this product. That is, 2,4,6-tris (p-
It is considered that bromophenyl) -1,3,5-triazine was produced. This composition corresponds to the desired monomer of the multibranched polymer. Although the composition in which Br is bonded to the benzene ring is shown, a composition in which Cl or I is bonded can be generated. Also in the case of these compositions, the synthesis method of the above-mentioned US Pat. No. 3,932,402 can be used.

Next, 2, 4, 6 produced in this way
A method for polymerizing -tris (p-bromophenyl) -1,3,5-triazine to produce a hyperbranched polymer will be described. The present inventors used the Grignard reaction as a polymerization method. All the reactions were performed in an argon gas atmosphere which is an inert gas. Moisture and oxygen, especially moisture,
To remove the solvent, the solvent tetrahydrofuran was distilled in the presence of calcium hydride, and the diethyl ether was used after being dried with calcium chloride overnight and then distilled.

0.218 g of 2,4,6-tris (p-bromophenyl) -1,3,5-triazine in a flask.
(0.40 mmol), and tetrahydrofuran 2.
5 ml was added and suspended in tetrahydrofuran. The suspension was cooled to −78 ° C. using a refrigerant in which dry ice was put in methanol, and n-concentration of 1.6 M was added while stirring.
Butyl lithium-hexane solution 0.25 ml (0.4
0 mmol) was added and the reaction was carried out for 10 minutes.

Here, the amount of the n-butyllithium-hexane solution added was such that Br in the 2,4,6-tris (p-bromophenyl) -1,3,5-triazine molecule was 1.
The quantity is controlled so that the amount of Li is replaced by Li. Thus, the composition represented by the above chemical formula 10 (X = Br) is obtained.

The yellow solution containing the obtained reaction intermediate was-
While maintaining the temperature at 78 ° C., 0.135 g (0.52 mmol) of magnesium bromide etherate dissolved in 0.5 ml of diethyl ether was added dropwise using a syringe. While continuing stirring, the mixture was returned to room temperature and reacted for 10 minutes to obtain a white reaction liquid containing a Grignard reagent. Thus, the composition represented by the chemical formula 11 (X = Br) is obtained. In this way, a monomer capable of undergoing a polymerization reaction was obtained.

15.0 mg (0.05 mmol) of nickel acetylacetonate as a catalyst was dissolved in 10 ml of tetrahydrofuran and prepared in another flask. The above-mentioned reaction liquid was extracted with a syringe and added dropwise to a tetrahydrofuran solution. The temperature was raised with stirring, and a polymerization reaction was carried out at 65 ° C. for 20 hours. The reaction solution was yellowish green.

The degree of polymerization can be changed by controlling the reaction time and temperature. When tetrahydrofuran is used, it is not possible to raise the temperature above 65 ° C. due to its boiling point, but it is possible to raise the reaction temperature by using another solvent.

It is considered that the degree of polymerization increases as the reaction temperature increases. On the contrary, if the reaction temperature is lowered, the degree of polymerization is considered to decrease. After the polymerization reaction was completed, the solution was returned to the room temperature and 0.1 ml of distilled water was added to stop the reaction. By adding water, the reactive group MgB
It is considered that r is terminated. In this way, the desired hyperbranched polymer was obtained.

Next, the obtained multibranched polymer was purified. The solvent contained in the reaction solution was distilled off using a rotary evaporator, 325 ml of chloroform was added to the obtained solid substance, and the mixture was heated to 60 ° C. and stirred to dissolve the unreacted raw materials. 325 ml of chloroform is an amount that dissolves all the raw materials even if all the raw materials are unreacted.

Then, the insoluble matter was filtered off, and 1N HCl2 was added.
Washed with 0 ml. Furthermore, 20 ml of distilled water and 20 ml of methanol were sequentially washed. 50 remaining solids
It was vacuum dried at 30 ° C. for 30 minutes to obtain 75.4 mg of a yellowish white polymer. The yield was 48%.

The polymer was placed under a microscope at 500 ° C.
However, the polymer did not melt. Therefore, it is considered that a material having excellent heat resistance was obtained. FIG. 3 shows the infrared absorption spectrum of the obtained polymer.
The characteristics can be more clearly read by comparison with FIG. 1, which is the infrared absorption spectrum of the raw material. 1607,
Strong absorption attributed to stretching vibrations of the benzene ring and the triazine ring is observed at 1566, 1504, and 1359 cm ^-1 . 1179, 1069, 1004, 839, 808
At cm- ¹ , absorption derived from C-H bending vibration can be confirmed as in the absorption curve of FIG. C- near 500 cm ^-1
Absorption due to Br stretching vibration is low, and C-Br
It is suggested that binding is reduced.

FIG. 4 shows the polymer structure deduced from these experimental results. Monomeric Mg shown in Chemical Formula 11
It is considered that X and X react with each other to be desorbed and polymerize two-dimensionally and three-dimensionally. The halogen group of the monomer is B
The resulting polymer, whether r, Cl, or I, will be similar.

Next, a method of doping the obtained multibranched polymer with cations will be described. The hyperbranched polymer was suspended in dimethylformamide to a concentration of 5.0 mg / ml. The suspension containing the polymer was applied onto a platinum electrode having a length of 1.0 cm and a width of 1.0 cm and heated to 100 ° C. to evaporate dimethylformamide. In this way,
A multi-branched polymer thin film having a weight of 0.016 mg was formed on the platinum electrode surface.

The electrolyte solution was prepared as follows. 0.
329 g (1.0 mmol) of tetra-n-butylammonium tetrafluoroborate was dissolved in 10 ml of acetonitrile, and 30 g of argon gas was added to remove dissolved oxygen.
Bubbling was performed for a minute. Acetonitrile used was distilled in the presence of calcium hydride in advance.

The electrolyte solution thus prepared was immersed with a platinum electrode coated with a polymer thin film as a working electrode, a platinum electrode having a length of 1.0 cm and a width of 1.0 cm as a counter electrode, and a silver wire as a reference electrode. . The potential between the reference electrode and the counter electrode was controlled on the basis of the potential of the reference electrode, and the polymer thin film was doped with n-butylammonium ion which is a cation in the electrolyte solution. The potential application and control were performed using a potentiostat device.

FIG. 5 shows a cyclic voltammogram of the hyperbranched polymer. The voltage sweep was performed with a negative voltage to dope the cations. Sweep speed is 50m
V / sec. In the figure, the downward current peak obtained in the vicinity of −1.6 V is derived from the doping of tetra-n-butylammonium ion. The upward current peak near -1.5V is due to the dedoping of tetra-n-butylammonium ion. That is, when the voltage applied to the working electrode is negatively increased, the tetra-n-butylammonium ion is doped, and when the applied voltage is returned to 0, the doped tetra-n-butylammonium ion is released from the polymer. Desorption and dedoping are performed. Thus, FIG. 5 shows the polymer membrane on the working electrode reversibly attaching and detaching ions.

It should be noted that the applied voltage was made positive and anion doping was also tried. However, it was not possible to dope the polymer with anions. The polymer showed an electrochromic phenomenon from white to reddish brown with the cation doping. Upon dedoping, the polymer exhibited an electrochromic phenomenon from reddish brown to white. The doping potential was determined to be -1.61V (vs Ag reference electrode). Also, doped tetra-n-
Butyl ammonium ion was determined to be 0.15 per polymer repeat unit.

As explained above, a novel hyperbranched polymer capable of reversibly doping with cations was obtained. Although the case where Br is used as the halogen element has been described, it will be apparent to those skilled in the art that other halogen elements can be used. In addition, other raw materials, solvents,
It will be apparent to those skilled in the art that the ions to be doped can be appropriately changed depending on the purpose, conditions, and the like.

The present invention has been described in connection with the preferred embodiments.
The present invention is not limited to these. For example,
It will be apparent to those skilled in the art that various modifications, improvements, and combinations can be made.

[0055]

As described above, according to the present invention,
Hyperbranched polymers that can be reversibly doped with cations are provided.

Further, with the reversible doping of cations, a hyperbranched polymer exhibiting electrochromic properties is provided. This multi-branched polymer can be used as a display material, a battery electrode material, and the like.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum of a monomer obtained by a production method.

FIG. 2 shows the general formula of the resulting monomer.

FIG. 3 shows an infrared absorption spectrum of a polymer.

FIG. 4 is a chemical formula showing an example of a polymer structure.

FIG. 5 shows a cyclic voltammogram of the obtained polymer.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C08L 79/04 LRA C08L 79/04 LRA H01M 4/60 H01M 4/60 (72) Inventor Masami Awai Tsukuba, Ibaraki Prefecture 2-302, Matsushiro, 1 prefecture, 3-24, Matsushiro, Ichi

Claims (8)

[Claims] 1. A compound of the general formula A multi-branched polymer having a repeating unit represented by: 2. A multi-branched polymer obtained by doping the multi-branched polymer according to claim 1 with a cation. 3. The hyperbranched polymer according to claim 2, wherein the cation is an alkali metal ion or a quaternary alkylammonium ion. 4. A battery electrode containing the hyperbranched polymer according to claim 1. 5. A heat resistant material comprising the hyperbranched polymer according to claim 1. 6. A display material containing the hyperbranched polymer according to claim 1. 7. (a) General formula: From the compound represented by the general formula: A method for producing a multi-branched polymer, comprising: a step of producing a Grignard reagent represented by the step (b); 8. A compound of the general formula A method of using a multi-branched polymer, comprising: a step of doping a multi-branched polymer having a repeating unit represented by with a cation; and a step of de-doping the cation from the multi-branched polymer doped with the cation.