JPH0725868B2 - Precursor of long-chain-substituted polyphenylene vinylene, method for producing long-chain-substituted polyphenylene vinylene, and highly conductive composition - Google Patents

Description

The present invention relates to a precursor of long-chain substituted polyphenylene vinylene, a method for producing a long-chain substituted polyphenylene vinylene from the precursor, and the obtained long-chain substituted polyphenylene vinylene and a dopant. It relates to a highly conductive composition containing as an essential component.

<Prior Art> Since a conjugated polymer is a rigid polymer, it is generally insoluble and infusible and has poor shapeability. As an attempt to improve shapeability, it has been proposed to synthesize a water-soluble polymer sulfonium salt precursor, shape it into a film, and then thermally decompose it to obtain a conjugated polymer poly-p-phenylene vinylene. (Japanese Patent Laid-Open No. 59-199746). For example, after condensation polymerization of p-xylylene dimethylene bissulfonium salt,
The polymer sulfonium salt is cast-molded, and then the cast film obtained is subjected to a desulfonium salt reaction and hot stretching to obtain a stretched film-like poly-p-phenylene vinylene. Similarly, a stretched film of substituted poly-p-phenylene vinylene is also known (Japanese Patent Laid-Open No. Sho 60).
-11528 publication).

<Problems to be Solved by the Invention> However, the conjugated polymer obtained from the precursor is insoluble and infusible because of the rigid polymer, and once converted to the conjugated polymer, the polymer itself is shaped. Is difficult. Further, the water-soluble polymer sulfonium salt precursor is a polymer electrolyte, and its aqueous solution has a high viscosity, so a low-concentration aqueous solution must be used in order to facilitate handling, and special molding is required. Different methods are required. Further, the stability of the precursor is not sufficiently high in practical use because the precursor is easily converted to a conjugated polymer by heat or light.

The object of the present invention is to provide a thermally stable and easy-to-handle poly-long-chain alkoxy group nucleus substitution-a precursor of p-phenylene vinylene, and a poly-long-chain alkoxy group nucleus substitution soluble in an organic solvent from the precursor- It is an object of the present invention to provide a method for producing a precursor of p-phenylene vinylene and a highly conductive composition containing the obtained poly-long chain alkoxy group nucleus-substituted p-phenylene vinylene and a dopant as essential components.

<Means for Solving Problems> That is, the present invention is the invention described below.

(1) General formula (I) R ₁ : a hydrocarbon group having 7 to 20 carbon atoms R ₂ : a hydrocarbon group having 1 to 7 carbon atoms n: an integer of 2 or more m: a poly-long-chain alkoxy group nuclear substitution -p substantially represented by 1 or -p −
A precursor of phenylene vinylene.

(2) General formula R ₁ : hydrocarbon group having 7 to 20 carbon atoms R ₂ : hydrocarbon group having 1 to 7 carbon atoms n: integer of 2 or more m: elimination of -OR ₂ group of precursor substantially represented by m: 1 or 2 General formula (II) characterized by R ₁ : a hydrocarbon group having 7 to 20 carbon atoms n: an integer greater than or equal to 2 m: a poly-long-chain alkoxy group represented by an integer of 1 or 2 nucleus substitution -p-
Method for producing phenylene vinylene.

(3) A highly conductive composition, which comprises as an essential component a poly-long-chain alkoxy group nucleus-substituted-p-phenylene vinylene obtained by the production method of (2) above and a dopant.

Hereinafter, the present invention will be described in detail.

The long chain substituent OR ₁ of the present invention is an alkoxy group having 7 to 20 carbon atoms. For example, linear saturated alkoxy groups such as n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, n-lauryloxy, n-octadecyloxy, and n-eicosyloxy, or linear unsaturated alkoxy groups thereof. Examples thereof include straight-chain saturated alkoxy groups. Further, the substitution position of OR ₁ − to the benzene ring is not particularly limited, but when the number of the substituents is 1, 2-
Alternatively, 3-position is preferred, and in the case of two, 2,5-position is preferred.

The method for synthesizing the poly-long-chain alkoxy group nucleus-substituted-p-phenylene vinylene precursor of the present invention is not particularly limited, but a long-chain alkoxy group nucleus-substituted-p-xylylene dihalide disulfonium salt is used with an alkali. A method via a polymer sulfonium salt obtained by condensation polymerization is preferable because the reaction is easy.

In the method via a polymer sulfonium salt, long-chain alkoxy group nuclear substitution-long-chain alkoxy group nuclear substitution obtained by reaction of p-xylylene dihalide with dialkyl sulfide-
General formula (III) obtained by condensation polymerization of p-xylylenedisulfonium salt with water in an organic solvent soluble in water and water, for example, a mixed solvent of alcohols. R _1: a hydrocarbon radical R ₃ having 7 to 20 carbon atoms, R _4: a hydrocarbon group having 1 to 10 carbon atoms n: 2 or more integer m: 1~2 X ^-: polymer represented by counterions sulfonium Salt with alcohol (R ₂ OH)
A poly-long-chain alkoxy group nucleus-substituted-p-phenylenevinylene precursor is synthesized by reacting with a side chain sulfonium salt and an alcohol-derived alkoxy group (R ₂ O-). Can be done. The alkaline solution used for the condensation polymerization is preferably a strong basic solvent having a pH of 11 or more in water or an organic solvent, for example, a mixed solvent of alcohols and water, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, and Although a primary ammonium salt hydroxide, a sulfonium salt hydroxide, a strong basic ion exchange resin (OH type), etc. can be used, sodium hydroxide, potassium hydroxide, and a strong basic ion exchange resin can be used suitably.

R ₃ and R _{4 in} the general formula (III) are hydrocarbon groups having 1 to 10 carbon atoms,
For example, methyl, ethyl, propyl, isopropyl, n-
Examples thereof include butyl, 2-ethylhexyl, phenyl, cyclohexyl, and benzyl groups, and hydrocarbon groups having 1 to 6 carbon atoms are preferable, and methyl and ethyl groups are particularly preferable.

Further, as the counter ion X ⁻ in the general formula (II), any counter ion can be used by a conventional method. For example, halogen, hydroxyl group, boron tetrafluoride, perchloric acid, carboxylic acid, sulfonate ion and the like can be used, among which chlorine, bromine,
Halogen such as iodine and hydroxyl ion are preferred.

In the condensation polymerization reaction by the method of passing through a high molecular weight sulfonium salt, the polymer precursor obtained is sensitive to heat, light, ultraviolet rays, strong basic conditions, etc. Tend to be a polymer precursor having a conjugated structure, and may become heterogeneous. Therefore, the condensation polymerization reaction is relatively low temperature, that is, at least 50 ° C or lower, especially 25 ° C.
It is preferable to carry out the reaction at a temperature of not more than 0 ° C, more preferably not more than 5 ° C. The reaction time is not particularly limited, but is usually 1 minute to
The range is 50 hours.

The method for converting a polymer sulfonium salt into a polymer precursor having an alkoxy group in its side chain is not particularly limited as long as it is reacted with an alcohol, but the polymer sulfonium salt obtained is soluble in an organic solvent. Therefore, it is preferable from the viewpoint of operability that the compound is dissolved in an organic solvent and then reacted with an alcohol. At this time, if the reaction temperature is low, the reaction does not proceed sufficiently, and if the reaction temperature is high, side chain elimination reaction occurs in addition to the substitution reaction, and a conjugated polymer is produced, which is not preferable. Usually, 5 ° C to 70 ° C is preferable, and more preferably
10 to 50 ° C.

The side chain alkoxy group (R ₂ O—) is eliminated as R ₂ OH from the polymer precursor represented by the general formula (I) thus obtained to obtain a conjugated polymer, poly-long-chain alkoxy. A nucleus-substituted -p-phenylene vinylene can be produced. The dealkoxy group treatment can be performed by applying conditions such as heat, light, ultraviolet rays and strong base treatment, but heat treatment is preferable. In order to obtain a highly conductive composition, it is important to carry out the dealkoxy group treatment of the polymer precursor in an inert atmosphere. The inert atmosphere here means an atmosphere in which the polymer is not deteriorated during the treatment, and it is particularly necessary to prevent the oxidation reaction by oxygen or air. Generally, it is carried out using an inert gas such as nitrogen, argon or helium, but this may be carried out under vacuum or in an inert medium. When the dealkoxy group treatment is carried out by heat, heat treatment at an excessively high temperature causes decomposition of the produced conjugated polymer, and the reaction is slow at low temperatures, which is not practical.
C. to 400.degree. C., preferably 70.degree. C. to 350.degree. C. are suitable. The treatment time can be appropriately selected depending on the treatment temperature, but the range of 1 minute to 10 hours is industrially practical.

In order to obtain poly-long chain alkoxy group nucleus-substituted p-phenylene vinylene which is highly soluble and has high conductivity, it is preferable that the molecular weight is sufficiently large, and at least the polymer of the general formula (I) or the general formula (III) The polymer precursor (1) has a degree of polymerization n of 2 or more, preferably 5 to 50,000, and has a high molecular weight that elutes before the solvent elution position corresponding to standard polystyrene having a molecular weight of 2800 in the molecular weight measurement by gel permeation chromatography. Things are used effectively.

Further, the molded product of the polymer precursor can be stretched and oriented. That is, a polymer precursor having an alkoxy group in the side chain can be stretched and oriented and heat-treated. In particular, this polymer precursor is also soluble in organic solvents, so it is possible to prepare a high-concentration polymer precursor solution, which can be molded compared to conventional polymer precursor solutions using water as a solvent. Suitable for getting things. Also obtained poly-long-chain alkoxy group nuclear substitution-
It is also possible to swell or dissolve p-phenylene vinylene in a solvent for cast molding, or to heat and stretch the molded product.

Next, the poly-long chain alkoxy group nucleus-substituted-p-phenylene vinylene obtained by the present invention 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 or the like, or a compound that has been found to have an effect of improving conductivity by forming an intercalation compound of graphite is effectively used. The composition can be obtained by any method, but it is known in the art that chemical doping,
It is preferable to dope by a method such as electrolytic doping, photodoping, or ion implantation.

Specifically, as the electron acceptor, halogen compounds: fluorine, chlorine, bromine, iodine, iodine chloride, iodine trichloride, iodine bromide Lewis acids: phosphorus pentafluoride, arsenic pentafluoride, antimony pentafluoride , Boron trifluoride, Boron trichloride, Boron tribromide, Sulfur trioxide Proton acids: Hydrogen fluoride, Hydrogen chloride, Nitric acid, Sulfuric acid, Perchloric acid, Fluorinated sulfonic acid, Chlorosulfonic acid, Trifluoromethanesulfone Acids Transition metal chlorides: titanium tetrachloride, zirconium tetrachloride, hafnium tetrachloride, niobium pentachloride, tantalum pentachloride, molybdenum pentachloride, tungsten hexachloride, iron trichloride Organic compounds: tetracyanoethylene, tetracyanoquinodi Methane, chloranil, dichlorodicyanobenzoquinone Electron donors include alkali metals: lithium, sodium, potassium, ruthenium Examples include bidium and cesium quaternary ammonium salts: tetraalkylammonium ions.

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 preferred content is 0.01 to 2.0 moles of the dopant with respect to the conjugated polymer repeating unit of the general formula (II). When the mole number is small, the conductivity is not high, and when the mole number is large, the conductivity is high. Is uneconomical because it tends to saturate. Among these doping agents, a dopant that does not react with the resulting conjugated double bond and the long-chain alkoxy group nucleus-substituted-p-phenylene group of the general formula (II) is preferable because it gives a highly conductive composition. In particular, sulfur trioxide, sulfuric acid or iodine can be mentioned as effective doping agents.

The composition of the present invention can give high conductivity of about 30 S / cm. Further, the stretched composition gives higher conductivity and exhibits electrical anisotropy, and can give anisotropy of 5 times or more in the stretching direction and the direction perpendicular thereto.

In order to provide high conductivity, it is highly preferable to perform the composition molding operation with the doping agent under an inert atmosphere.

<Effect of the Invention> The poly-long-chain alkoxy group nucleus-substituted-p-phenylene vinylene precursor of the present invention is thermally stable and easy to handle. The precursor is soluble in an organic solvent, and since the obtained conjugated polymer is at least swollen or soluble in an organic solvent, the conjugated polymer itself can be subjected to shaping or stretching treatment, and doping can be performed. It is possible to obtain a composition having high conductivity by performing, for example, electricity utilizing conductivity,
Various applications to electronic materials are possible.

<Examples> The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 2.5 g of 2,5 dilauryloxy-p-xylylene bis (dimethylsulfonium bromide) was dissolved in a mixed solvent of 50 ml of methanol and 5 ml of deionized water, and then 3.4 ml of a 1N aqueous caustic soda solution and 10 ml of methanol. Was added dropwise over 15 minutes, 50 ml of methanol was added, and then 0 ° C to 5 ° C.
When stirring was continued at 0 ° C for 30 minutes, a white precipitate was formed.
The precipitate was separated, dissolved in 30 ml of chloroform, mixed with 50 ml of methanol and allowed to stand for 1 day to cause precipitation. This precipitate was dissolved in chloroform, cast, and dried in a nitrogen stream to obtain a precursor film. When the thermogravimetric change of the obtained film was examined, weight loss was observed at 150 ° C to 160 ° C, and the film turned red. When the molecular species in the gas generated at this time were analyzed by a quadrupole mass spectrometer, no remarkable peak was observed near the mass number 62 corresponding to dimethyl sulfide.

The elemental analysis of the obtained precursor showed that the elemental C H Br S experimental value was 78.61 11.45 0.2 0.13, the calculated value was 78.88 11.55 − −, and the large amounts of Br and S expected from the sulfonium salt were not found. It was in good agreement with the element content calculated from the structure in which the group was substituted on the side chain. When the infrared absorption spectrum was measured, absorption attributable to a methoxy group was found at 1100 cm ^-1 . When the resulting chloroform solution of the obtained precursor was analyzed by gel permeation chromatography, the weight average molecular weight converted to standard polystyrene was 1 × 10 ⁵ .

This film was placed under a nitrogen atmosphere in a horizontal tubular furnace to
A static heat treatment was carried out at 0 ° C. for 30 minutes to obtain a poly-2,5-dilauryloxy-p-phenylenevinylene film having a red color. Elemental analysis values are C: 81.3% (81.7), H: 1
The result was 1.6 (11.5) (the values in parentheses were calculated from the structural formula), which was in agreement with the structural formula. Further aliphatic hydrocarbon group 2900 cm ^-1 in an infrared absorption spectrum, a benzene ring substituted alkoxy groups in 1220 cm ^-1, absorption of trans-vinylene to 970 cm ^-1 was observed. From these results, the structure of poly 2,5-dilauryloxy-p-phenylene vinylene was confirmed.

Further, when iodine, which is an electron acceptor compound, was used for this film and doping was carried out from the gas phase at room temperature by a conventional method, a conductivity of 0.9 S / cm was exhibited in 4 hours. The conductivity was measured by the four-terminal method.

Example 2 The precursor film (length 2 cm, width 2 cm) obtained in Example 1 was stretched up to 4 times in a nitrogen atmosphere using a horizontal tubular furnace,
A static heat treatment was carried out at 0 ° C. for 30 minutes to obtain a stretched poly 2,5-dialryloxy-p-phenylene vinylene film.

Further, iodine was used as an electron acceptor compound in this film, and doping from the gas phase was carried out at room temperature by a conventional method. As a result, a conductivity of 14.3 S / cm was exhibited in 1 hour.

Comparative Example 1 The precipitate obtained after polymerization and dialysis in Example 1 was dissolved in chloroform, cast, and dried in a nitrogen stream to obtain a precursor film having a sulfonium salt as a side chain. When the thermogravimetric change of the obtained film was examined, weight reduction was observed only at 90 ° C to 100 ° C, and no weight reduction was observed at 150 ° C to 160 ° C. When the molecular species in the gas generated at this time were analyzed with a quadrupole mass spectrometer, a remarkable peak was seen at a mass number of 62 corresponding to dimethyl sulfide, and 90 to 100
It was confirmed that dimethyl sulfide was generated at ° C.

The precursor film having this sulfonium salt in the side chain is subjected to a standing heat treatment in a nitrogen atmosphere in a horizontal tubular furnace at 100 ° C for 30 minutes, and poly-2,5-dilauryloxy- having a red color is formed. A p-phenylene vinylene film was obtained.
The elemental analysis values were C: 81.1% (81.7) and H: 11.7 (11.5) (numerical values in parentheses were calculated from the structural formula), which was consistent with the structural formula. In addition, the infrared absorption spectrum is 2900 cm
^-1 aliphatic hydrocarbon group, a benzene ring substituted alkoxy groups in 1220 cm ^-1, absorption of trans-vinylene to 970 cm ^-1 was observed. From these results, poly-2,5-dilauryloxy-
The structure of p-phenylene vinylene was confirmed.

Furthermore, when iodine, which is an electron acceptor compound, was used for this film and doping was performed from the gas phase at room temperature by a conventional method, a conductivity of 0.8 S / cm was exhibited in 4 hours.

Example 3 9.4 g of 2,5-diheptyloxy-p-xylylene bis (dimethylsulfonium bromide) was dissolved in a mixed solvent of 100 ml of methanol and 20 ml of ion-exchanged water, and then a mixed solution of 15 ml of 1N aqueous caustic soda solution and 70 ml of methanol. Was added dropwise over 20 minutes, and stirring was continued at 0 ° C to 5 ° C for 40 minutes, whereupon a white precipitate was formed. This precipitate was separated, dissolved in 40 ml of chloroform, and the solution was added to 80 ml of methanol.
When the mixture was mixed with the above and left overnight, a precipitate was formed. This precipitate was dissolved in chloroform, cast, and dried in a nitrogen stream to obtain a precursor film. When the thermogravimetric change of the obtained film was examined, weight loss was observed at 150 ° C to 160 ° C, and the film turned red. Elemental analysis of the precursor film showed that the elemental C H Br S experimental value was 77.36 10.52 <0.1 0.15 Calculated value 76.24 10.5 − −, and the large amounts of Br and S expected from the sulfonium salt were not found, and the methoxy of methanol was not observed. It was in good agreement with the element content calculated from the structure in which the group was substituted on the side chain. When the infrared absorption spectrum was measured, absorption attributable to a methoxy group was found at 1100 cm ^-1 .

This film was placed under a nitrogen atmosphere in a horizontal tubular furnace for 25
A static heat treatment was carried out at 0 ° C. for 30 minutes to obtain a poly-2,5-diheptyloxy-p-phenylene vinylene film having a red color. Its structure was confirmed by elemental analysis and infrared absorption spectrum.

Further, iodine was used as an electron acceptor compound in this film, and when it was doped from the gas phase at room temperature by a conventional method, it showed an electric conductivity of 15.1 S / cm in 1 hour.

Example 4 The polymer precursor chloroform solution obtained in Example 3 was concentrated twice at 40 ° C. under reduced pressure, then slowly extruded into a water through a nozzle having a diameter of 2 mm and spun. After drying the generated filamentous material under reduced pressure, using a horizontal tubular furnace under a nitrogen atmosphere.
A red uniaxially stretched poly-2,5-diheptyloxy-p-phenylenevinylene yarn was obtained by stretching at 2.1 times with heat treatment at 250 ° C.

When the obtained yarn was doped with sulfuric acid, the yarn turned black and exhibited an electric conductivity of 30.7 S / cm.

Claims (3)

[Claims] 1. A general formula R ₁ : a hydrocarbon group having 7 to 20 carbon atoms R ₂ : a hydrocarbon group having 1 to 7 carbon atoms n: an integer of 2 or more m: a poly-long-chain alkoxy group nuclear substitution -p substantially represented by 1 or -p −
A precursor of phenylene vinylene. 2. General formula R ₁ : hydrocarbon group having 7 to 20 carbon atoms R ₂ : hydrocarbon group having 1 to 7 carbon atoms n: integer of 2 or more m: elimination of -OR ₂ group of precursor substantially represented by m: 1 or 2 General formula characterized by R ₁ : a hydrocarbon group having 7 to 20 carbon atoms n: an integer greater than or equal to 2 m: a poly-long chain alkoxy group represented by m or 1;
Method for producing phenylene vinylene. 3. A highly conductive composition comprising a poly-long-chain alkoxy group nucleus-substituted p-phenylene vinylene obtained by the production method according to claim 2 and a dopant as essential components.