JP2526976B2 - Novel polymer compound, method for producing the same, and method for producing a conjugated polymer from the polymer compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a novel polymer compound which can be converted into poly-2,5-di-lower alkoxy-substituted phenylene vinylene, a method for producing the same, and a conjugated system from the novel polymer compound. Polymer-
It relates to a method for producing 2,5-di-lower alkoxy-substituted phenylene vinylene.

<Prior Art> Poly-2,5-di-lower-alkoxy-substituted phenylene vinylene is known as a linear conjugated polymer (JP-A-60-11528).
Japanese Patent Laid-Open Publication No. 1993), the polymer gives high electric conductivity by doping with various dopants, and is expected to be used as various electric / electronic materials in various applications.

In addition, the above-mentioned conjugated polymer is, for example, 2,5-dialkoxy-p-xylylenebis (dialkylsulfonium halide) is condensation-polymerized in the presence of an alkali to synthesize a polymer sulfonium salt, and then this polymer sulfonium salt is synthesized. It is produced by removing the sulfonium salt by heat treatment or the like.

Further, since the above-mentioned polymer sulfonium salt is soluble in water or the like, a conjugated polymer having a desired shape can be obtained by subjecting the polymer sulfonium salt to a film-like or thread-like shape at the stage of the polymer sulfonium salt, and then performing a defluphonium salt treatment. It has the characteristics that can be obtained.

<Problems to be Solved by the Invention> However, the above-mentioned polymer sulfonium salt is not always stable to heat and light, and gradually while being formed into a solution from a stage formed by polymerization to a desired shape. However, since the sulfonium salt of the side chain is eliminated, it is necessary to shield the light or perform it at a low temperature in the operation.

The object of the present invention is to provide a novel polymer compound which is stable at room temperature, soluble in an organic solvent and excellent in shapeability, a process for producing the same, and a poly (2,5-di-lower) which is a conjugated polymer from the novel polymer compound. It is to provide a method for producing an alkoxy-substituted phenylene vinylene.

<Means for Solving the Problems> That is, the present invention provides the general formula (1) (In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, and R ₂ is 1 carbon atom.
To 4 alkyl groups, and n is a degree of polymerization of 10 or more), a novel polymer compound having a repeating unit represented by the general formula (2) (In the formula, R ₁ and n are as defined above, R ₃ and R ₄ are a hydrocarbon group having 1 to 10 carbon atoms, A ^- is a counter anion, excluding an organic acid anion) polymeric sulfonium salt represented by A ^- The product obtained by substituting an organic acid anion for R ₂ OH (R ₂ is a carbon number 1
~ 4 alkyl groups are shown. ) A method for producing a novel polymer compound of the above formula (1), characterized by reacting with an alcohol represented by the formula (1), and a polymer compound containing a repeating unit represented by the above general formula (1) as a main component. General formula (3) characterized by elimination of the OR ₂ side chain The present invention provides a method for producing poly-2,5-di-lower alkoxy-substituted phenylene vinylene containing a repeating unit represented by the formula (R ₁ and n are the same as above) as a main component.

The novel polymer compound of the present invention is obtained by the method described below in which the sulfonium salt side chain of the polymer of the formula (2) is described below, and the novel polymer compound is soluble in an organic solvent and has a shapeability. It is also found that it is superior in stability and superior in stability to those having a sulfonium salt side chain.

 Hereinafter, the present invention will be described in detail.

The polymeric sulfonium salt used for producing the precursor of the present invention has the general formula (2) In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl and isobutyl. Also, n
Is as described above, and R ₃ and R _{4 each} have 1 to 1 carbon atoms.
10 hydrocarbon groups, such as methyl, ethyl, propyl,
It is a butyl, hexyl, cyclohexyl, octyl group or the like, but a methyl or ethyl group is preferable.

These can be produced, for example, by the method described in JP-A-60-11528.

That is, the following formula (4) It can be obtained by condensation polymerization of a sulfonium salt monomer represented by the formula (1) in the presence of an alkali.

As the counter anion A ⁻ of the sulfonium salt, any one except an organic acid anion can be used, but for example, a halogen anion such as Cl or Br is preferable.

As the solvent for the condensation polymerization, water, a mixed solvent of water and alcohol, or the like is used, but a solvent mainly composed of water is preferable in order to increase the solubility of alkali.

The alkaline solution used for the condensation polymerization is preferably a strong basic solution having a pH of 11 or more, and sodium hydroxide, potassium hydroxide, calcium hydroxide, a strongly basic ion exchange resin (OH type) or the like can be preferably used as the alkali. .

The condensation polymerization reaction is preferably performed at 25 ° C. or lower, particularly 10 ° C. or lower. The reaction time may be appropriately determined depending on the polymerization temperature and is not particularly limited, but is usually 5 minutes to 20 minutes.
It is within the range of time.

After the polymerization, an acid such as HC1 or HBr is added to the reaction solution to neutralize it.

The following formula (2) generated in the reaction solution after neutralization The polymer sulfonium salt represented by is dissolved.

Next, the counter anion A ⁻ of the polymer sulfonium salt is replaced with an organic acid ion, and the substitution reaction is carried out by neutralizing the solution of the polymer sulfonium salt solution described above, or by dialysis from this solution, reverse osmosis separation or the like to remove an alkali salt. It can be performed by adding and mixing an organic salt to the removed aqueous solution.

As the organic acid ion, the following formula (5) (Here, R ₅ is an alkyl group having 1 to 18 carbon atoms, M is an alkali metal, and L is an integer of 0 to 3.) An aromatic sulfonate ion (for example, benzene sulfonic acid, m or p). -Toluenesulfonic acid, p-ethylbenzenesulfonic acid, 2,4-dimethylbenzenesulfonic acid, 2,4,6-
Trimethylbenzene sulfonic acid, 2,4-diethylbenzene sulfonic acid ion, etc.), alkyl sulfate ion having an alkyl group having 1 to 20 carbon atoms (for example, lauryl sulfate, 1
-Eicosyl sulfate ion, etc.) and a carboxylate ion having an alkyl group having 2 to 20 carbon atoms (eg, propionic acid, butyric acid, stearate ion, etc.), which are used in the form of salts such as sodium and potassium in use. Is preferred. Particularly preferred is p-toluenesulfonate.

The amount of the organic acid ion used may be equal to or more than the equivalent amount of the ions contained in the polymer sulfonium salt solution, but particularly 2 to
About 5 times equivalent is preferable. When the amount is less than the equivalent, substantially all of A ⁻ of the polymer sulfonium salt is not replaced with the organic acid ion, and it is meaningless if the amount is more than necessary.

The reaction temperature is preferably 10 ° C or lower, particularly preferably 5 ° C or lower. Further, the reaction time is not particularly limited,
Usually, about 10 minutes to 5 hours is selected. As the reaction proceeds, a compound in which A ^{− of the} high molecular weight sulphonium salt is replaced with the aromatic sulfonate ion used is generated and precipitated.

Then, the precipitate was converted into a compound represented by the general formula R ₂ OH (R ₂ has 1 to 4 carbon atoms).
The precipitate is dissolved into a homogeneous solution by adding it to the alcohol represented by the formula (1), stirring and reacting, but after a while, the solution becomes cloudy and precipitates. This precipitate has the following formula (1) (R ₁ , R ₂ , and n are as described above), which is a precursor of the conjugated polymer.

The alcohol used here is preferably an alcohol having 1 to 4 carbon atoms, and particularly preferably methanol or ethanol. The alkoxy group on the side chain of the precursor corresponds to the alkoxy group of the alcohol used.

The precursor of the present invention is insoluble in water and soluble in an organic solvent such as dimethylformamide, dimethylacetamide, dimethylsulfoxide, dioxane and chloroform, and from the solution, any known method such as a film or fiber can be used. It is excellent in isoformability that can make shaped products and is more stable than conventional polymer sulfonium salts, and the obtained cast film shows elimination of alkoxy groups even at room temperature. I couldn't do it.

Further, the degree of polymerization n of the above precursor is preferably sufficiently large in consideration of obtaining a conjugated polymer which gives high conductivity, and is usually 10 or more, and particularly preferably 20 to 50,000.
Those having a particularly high degree of polymerization can be obtained by dialyzing an aqueous solution of a high molecular weight sulfonium salt using a dialysis membrane having a large molecular weight cutoff.

Further, this precursor is subjected to heat treatment or the like to eliminate the side chain (R ₂ O-) of the alkoxy group, whereby a conjugated polymer, poly-2,5-dialkoxy group-substituted phenylene vinylene can be obtained. Moreover, it is preferable to perform the elimination treatment of the alkoxy group (R ₂ O-) of the polymer precursor in an inert atmosphere. Usually the processing temperature is 100-350 ℃, preferably 150 ℃ -300
℃ is suitable. In addition, the precursor contains trace amounts of acids, such as HC1, H
Those containing Br, etc. are treated with an alkoxy group (R ₂
The elimination reaction of O-) is promoted.

The treatment time can be appropriately selected depending on the treatment temperature and is not particularly limited, but is usually in the range of 10 minutes to 10 hours.

In addition, the polymer precursor may be shaped into a film, a fibrous shape, or the like, and then stretched and oriented to perform the above heat treatment. The stretching orientation can be performed before the elimination treatment of the alkoxy group (R ₂ O-) or simultaneously with the treatment.

Poly-2,5- which is a conjugated polymer obtained by the treatment
The dialkoxy group-substituted phenylene vinylene can be made into a highly conductive composition by causing an electron acceptor or an electron donor (referred to as a dopant) to act. Here, as the dopant, a known conductive polymer compound such as polyacetylene is used, or a compound that has been found to have an effect of improving conductivity by forming an intercalation compound of graphite is used. The composition can be obtained by any method, but it is preferable to dope by a conventionally known method such as chemical doping, electrolytic doping, photodoping, or ion implantation.

Specifically, as the electron acceptor, halogen or an interhalogen compound such as fluorine, chlorine, bromine, iodine, iodine chloride, iodine trichloride, iodine bromide, phosphorus pentafluoride, arsenic pentafluoride, antimony pentafluoride. Lewis acids such as boron trifluoride, boron trichloride, boron tribromide and sulfur trioxide,
Proton acids such as hydrogen fluoride, hydrogen chloride, nitric acid, sulfuric acid, perchloric acid, fluorinated sulfonic acid, chlorinated sulfonic acid, and trifluorinated metasulfonic acid, titanium tetrachloride, zirconium tetrachloride,
Hafnium tetrachloride, niobium pentachloride, tantalum pentachloride, molybdenum pentachloride, tungsten hexachloride, transition metal chlorides such as iron trichloride, tetracyanoethylene, tetracyanochimedidimethane, chloranil, organic compounds such as dichlorodicyanobenzoquinone, Also, as an electron donor, lithium,
Examples thereof include alkali metals such as sodium, potassium, rubidium and cesium, and quaternary ammonium salts such as quaternary alkylammonium, with sulfur trioxide, sulfuric acid or iodine being particularly preferred.

Although the preferable content of the doping agent varies depending on the type of the doping agent, it can generally be arbitrarily changed depending on the doping conditions such as the doping time and the concentration of the doping agent. Generally, the preferable content is that the number of moles of the dopant with respect to the repeating unit of the conjugated polymer is 0.
It is 01 to 2.0 mol, and if the number of moles is small, high conductivity is not obtained, and if the number of moles is large, the electric conductivity tends to be saturated, which is not economical.

<Effects of the Invention> As described above, the novel polymer compound of the present invention is more stable than the polymer sulfonium salt and is excellent in shapeability because it is soluble in an organic solvent. Further, the polymer compound of the present invention can be easily converted into a conjugated polymer by heat treatment or the like as a precursor of the conjugated polymer, and a conjugated polymer film having a high draw ratio, a molded article such as a fiber, Further, by doping these, a composition having high conductivity is provided.

<Examples> The present invention will be described in more detail with reference to Examples.

Example 1 After dissolving 3.1 g of 2,5-dimethoxy-p-xylylene bis (dimethylsulfonium bromide) in 50 ml of ion-exchanged water, 50 ml of 0.14N NaOH aqueous solution was added dropwise at 0-5 ° C. over 15 minutes, After dropping, the mixture was reacted at 0 to 5 ° C for 7 hours.
Then, an HBr aqueous solution was added to neutralize.

Then, a powder of sodium p-toluenesulfonate in an amount about 3 times equivalent to that of Br ⁻ contained in the reaction solution after neutralization was added to the reaction solution and stirred to form a precipitate. The precipitate was taken out, poured into a large amount of methanol at 20 ° C., and stirred, whereby the precipitate was uniformly dissolved. When stirring was further continued, the liquid began to turn cloudy, and the precipitate obtained after 1 hour was collected.

The precipitate was washed with methanol and then dried to perform elemental analysis of the powder sample, which revealed that hydrogen was 7.25%,
It was in good agreement with the theoretical values of 7.27% and 68.02%, respectively, of the precursor of poly-2,5-dimethoxyphenylenevinylene in which carbon was 67.61% and R ₁ and R ₂ corresponded to methyl groups in the above formula (1). .

Also, dissolve this sample in deuterium-substituted chloroform,
H-NMR was measured and found to be 6.9,6.6,4.9,3.8,3.7,3.2,
A proton signal was observed at around 2.9. The infrared absorption spectrum is shown in Fig. 1 and is 1100 cm ^-1.
Absorption of ether bond was observed. From these analysis results, it was confirmed that the precursor polymer had a methoxy group in the side chain. Further, when the degree of polymerization was measured by gel permeation chromatography using chloroform as a solvent, the degree of polymerization determined from the number average molecular weight in terms of polystyrene was
It was 850.

The film (length: 2 cm, width: 2 cm) obtained in Example 1 was heat-treated in an electric furnace at 200 ° C. for 1 hour in a nitrogen atmosphere to obtain a red film. This structure has a poly-2, since the characteristic absorption of the elemental analysis value and the infrared absorption spectrum match the characteristic absorption of the sample obtained by the known method.
It was confirmed to be 5-dimethoxyphenylene vinylene.

The film obtained above was exposed to an iodine atmosphere at room temperature overnight for doping. When the conductivity of the film was measured by the four-terminal method, it showed a conductivity of 187 S / cm.

Example 2 Instead of 2,5-dimethoxy-p-xylylene bis (dimethylsulfonium bromide), 2,5-diethoxy-p-
A precursor polymer was obtained in the same manner as in Example 1 except that equimolar amounts of xylylenebis (dimethylsulfonium bromide) were used. When analyzed in the same manner as in Example 1, it was confirmed to have an ethoxy group in the side chain and to be a precursor of poly-2,5-diethoxyphenylene vinylene. Then, the precursor film was subjected to side chain elimination treatment at 150 ° C. to prepare a poly-2,5-diethoxyphenylene vinylene film. After performing electrolytic doping in LiC10 ₄ / acetonitrile This film was measured for conductivity in the same manner as in Example 1, showed a conductivity of 113S / cm.

Example 3 In the same manner as in Example 1, a conjugated polymer precursor film having a methoxy group in its side chain was obtained. The film 10
When the methoxy group side chain was eliminated while uniaxially stretching at a temperature of 0 to 200 ° C. under various conditions, a poly-2,5-dimethoxyphenylene vinylene film having a stretching ratio of 3 to 5 was obtained. On the other hand, a cast film of a high molecular weight sulfonium salt was uniaxially stretched and desulfonium salt treated under various conditions at a temperature of 100 to 200 ° C, but only a poly-2,5-dimethoxyphenylene vinylene film with a draw ratio of 2 times or less was obtained. I couldn't get it. The stretching ratio obtained by the method of the present invention is 3.2.
When a film obtained by doping a double uniaxially stretched poly-2,5-dimethoxyphenylene vinylene film in the same manner as in Example 1 was measured for electric conductivity, it showed a conductivity of 253 S / cm.

[Brief description of drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of the novel polymer compound of the present invention obtained in Example 1.

Claims (3)

(57) [Claims] 1. A general formula (In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, and R ₂ is 1 carbon atom.
To 4 alkyl groups, and n represents a degree of polymerization of 10 or more), which is a novel polymer compound having a repeating unit represented by the following formula. 2. General formula (In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, R ₃ and R ₄ are hydrocarbon groups having 1 to 10 carbon atoms, A ⁻ is a counter anion excluding an organic acid anion, and n is a degree of polymerization of 10 or more. The product obtained by substituting organic acid ion for A ^{− of the} polymer sulfonium salt represented by R ₂ OH (R ₂ represents an alkyl group having 1 to 4 carbon atoms). General formula characterized by reacting with alcohol A method for producing a novel polymer compound containing a repeating unit represented by the formula (R ₁ , R ₂ and n are the same as above) as a main component. 3. General formula (In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, and R ₂ is 1 carbon atom.
To 4 of an alkyl group, n is a degree of polymerization of 10 or more)
General formula characterized by elimination treatment of R ₂ side chain A method for producing poly-2,5-di-lower alkoxy-substituted phenylene vinylene containing a repeating unit represented by the formula (R ₁ and n are the same as above) as a main component.