JP2777659B2 - Resistance roller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICATIONS The present invention is stable at 10 ⁵ to 10 ¹³ Ω regardless of ambient environmental conditions.
A resistance roller with an electrical resistance film having a volume resistivity in the range of cm;

2. Description of the Related Art For example, a developing resistance roller for an electronic copying machine has a function of uniformly charging the surface thereof, uniformly attaching toner to the surface thereof, and transporting the toner.
10 ⁵ to 10 ¹² Ωcm from semiconductor region to insulator region
It is said that it is desirable to be within the range.

Such a resistance roller is usually formed by providing a conductive polymer layer on the peripheral surface of a metal shaft, and such a conductive polymer is conventionally formed of a conductive filler in a synthetic resin or synthetic rubber. Are kneaded and dispersed. However, in such a resistance roller, the resistance value is an apparent resistance value due to the contact resistance of the conductive filler, and it is difficult to obtain a uniform contact between the conductive fillers. It is not easy to stably obtain a resistance value in the above range, and the resistance value varies greatly.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-described problem in the conventional resistance roller, and has a stable range of 10 ⁵ to 10 ¹³ Ωcm regardless of the ambient environment conditions. It is an object of the present invention to provide a resistance roller provided with an electric resistance film having the above volume resistivity.

Means for Solving the Problems According to the present invention, in a resistance roller provided with an electric resistance film made of an organic polymer on a peripheral surface of a metal shaft, the organic polymer has a general formula (Wherein, m and n represent the molar fractions of the quinone diimine structural unit and the phenylenediamine structural unit in the repeating unit, respectively, and are represented by 0 <m <1, 0 <n <1, and m + n = 1). Having a quinone diimine structural unit and a phenylenediamine structural unit as main repeating units, soluble in an organic solvent in an undoped state, and having an intrinsic viscosity (η) of 0.3 in N-methylpyrrolidone measured at 30 ° C.
Of the skeleton vibrations of para-substituted benzene in the laser Raman spectrum obtained by pumping with light of a wavelength of 457.9 nm while being at least 40 dl / g, the Raman line of the skeleton stretching vibration appearing at a higher wavenumber than 1600 cm ^-1 Strength Ia and 1600cm ^-1
Raman intensity of skeleton stretching vibration appearing at lower wavenumber than
A resistance roller having an Ib ratio Ia / Ib of 1.0 or more is provided.

A polymer having a quinone diimine structural unit represented by the above general formula and a phenylenediamine structural unit as a main repeating unit used in the present invention, which is soluble in an organic solvent in an undoped state, has a predetermined intrinsic viscosity and laser Raman. Polyaniline having spectral characteristics (hereinafter referred to as undoped polyaniline) is
In the presence of a protonic acid having an acid dissociation constant pKa of 3.0 or less, the temperature of aniline in a solvent is reduced to 5 ° C or less, preferably 0 ° C.
An aqueous solution of an oxidizing agent having a standard electrode potential of 0.6 V or more, which is determined as an electromotive force in a reduction half-cell reaction based on a standard hydrogen electrode, is maintained at the following temperature, and 1 mole of the oxidizing agent is added to 1 mole of aniline. Is defined as the amount divided by the number of electrons required to reduce one molecule of the oxidizing agent,
The aniline oxide polymer doped with the above-mentioned protonic acid (hereinafter, referred to as doped polyaniline) by gradually adding at least equivalent amount, preferably 2 to 2.5 equivalent amount,
Then, the doped polyaniline can be obtained by undoping with a basic substance.

First, the production of the doped polyaniline by oxidation of aniline in the presence of a protonic acid will be described.

As the oxidizing agent, manganese dioxide, ammonium peroxodisulfate, hydrogen peroxide, ferric salt, iodate and the like are particularly preferably used. Among them, for example, ammonium peroxodisulfate and hydrogen peroxide usually have a range of 1 to 1.25 mol per 1 mol of aniline since two electrons per molecule are involved in the oxidation reaction. The amount is used.

The protonic acid used in the oxidative polymerization of aniline is not particularly limited as long as the acid dissociation constant pKa value is 3.0 or less, and examples thereof include hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, borofluoric acid, and phosphoric acid. Inorganic acids such as hydrofluoric acid, hydrofluoric acid and hydroiodic acid, benzenesulfonic acid, p
-Aromatic sulfonic acids such as toluenesulfonic acid, methanesulfonic acid, alkanesulfonic acids such as ethanesulfonic acid,
Examples thereof include phenols such as picric acid, aromatic carboxylic acids such as m-nitrobenzoic acid, and aliphatic carboxylic acids such as dichloroacetic acid and malonic acid. Also, polymeric acids can be used. Examples of such a polymer acid include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, and polyvinyl sulfate.

The amount of protonic acid used depends on the mode of reaction of the oxidizing agent used. For example, in the case of manganese dioxide, the oxidation reaction is represented by MnO ₂ + 4H ⁺ + 2e ⁻ → Mn ²⁺ + 2H ₂ O.
It is necessary to use a protonic acid capable of supplying a double molar amount of protons. Also, in the case of hydrogen peroxide, since the oxidation reaction is represented by H ₂ O ₂ + 2H ⁺ + 2e ⁻ → 2H ₂ O, a protonic acid capable of supplying at least twice the amount of protons of hydrogen peroxide to be used is used. There is a need. On the other hand, in the case of ammonium peroxodisulfate, the oxidation reaction is represented by S ₂ O ₈ ²⁻ + 2e ⁻ → 2SO ₄ ²⁻ , and therefore, it is not particularly necessary to use a protonic acid. However, even when ammonium peroxodisulfate is used as the oxidizing agent, it is preferable to use an equimolar amount of the protonic acid with the oxidizing agent.

As a solvent in the oxidative polymerization of aniline, a solvent that dissolves aniline, a protonic acid, and an oxidizing agent and that is not oxidized by the oxidizing agent is used. Water is most preferably used, however, if necessary, alcohols such as methanol and ethanol, nitriles such as acetonitrile, N-methyl-2-pyrrolidone, polar solvents such as dimethyl sulfoxide, ethers such as tetrahydrofuran, Organic acids such as acetic acid can also be used. Also, a mixed solvent of these organic solvents and water can be used.

It is important to keep the temperature of the reaction mixture below 5 ° C. during the above oxidative polymerization reaction of aniline, especially while adding the oxidizing agent solution to the aniline solution. Therefore, the oxidant solution must be added slowly to the aniline so that the temperature of the reaction mixture does not exceed 5 ° C. When the oxidizing agent is added rapidly, the temperature of the reaction mixture increases due to external cooling to produce a low-molecular-weight polymer, or a solvent-insoluble oxidizing polymer even after dedoping described later. Is generated.

In particular, it is preferable to keep the reaction temperature at 0 ° C. or lower,
Thereby, after dedoping, a high molecular weight solvent-soluble polyaniline having an intrinsic viscosity [η] of 1.0 dl / g or more measured in N-methyl-2-pyrrolidone at 30 ° C. (the same applies hereinafter) is obtained. be able to.

The polyaniline doped with the protonic acid obtained in this way generally forms a salt with the protonic acid and, as is the case with many doped conductive organic polymers, generally has almost no conductivity. Does not dissolve in organic solvents.

However, polyaniline doped with such a protonic acid becomes soluble in an organic solvent by undoping. Since the undoping of the doped polyaniline is a kind of neutralization reaction, the basic substance that can be used for undoping is limited as long as it is a basic substance that can neutralize a protonic acid as a dopant. Although not particularly preferred, metal hydroxides such as aqueous ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide and calcium hydroxide are preferably used. In the undoping, a basic substance may be directly added to the reaction mixture after the oxidative polymerization of aniline, or the basic substance may be allowed to act after the polymer is once isolated.

Doped polyaniline obtained by oxidative polymerization of aniline usually has a conductivity of 10 ⁻⁶ S / cm or more,
It has a black-green color, but after undoping, is purple or purple-tinted copper. This discoloration is because the amine nitrogen of the salt structure in the polymer was changed to a free amine. The conductivity is usually on the order of 10 ^-10 S / cm. Therefore, the volume resistivity is 10 ⁹ Ω
・ It is on the order of cm. However, as described below, the value of the volume resistivity can be changed by adjusting the ratio of the quinone diimine structural unit to the phenylenediamine structural unit in the polymer.

The undoped polyaniline thus obtained has a high molecular weight and is soluble in various organic solvents. Such organic solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, 1,3-dimethyl-2.
-Imidazolidinone, sulfolane and the like. The solubility depends on the average molecular weight of the undoped polyaniline and the solvent, but 0.5 to 100% of the polymer is dissolved,
A 30% by weight solution can be obtained. In particular, undoped polyaniline shows high solubility in N-methyl-2-pyrrolidone, usually 20 to 100% of the polymer dissolves,
A 3 to 30% by weight solution can be obtained. However, it does not dissolve in tetrahydrofuran, 80% acetic acid aqueous solution, 60% formic acid aqueous solution, acetonitrile and the like.

According to the present invention, the resistive film according to the present invention can be obtained by dissolving the solvent-soluble undoped polyaniline in an organic solvent, applying the solution on an appropriate substrate, and drying and evaporating the solvent. Therefore, if a thin film of undoped polyaniline is formed on a metal axis having a smooth surface, a resistance roller having a volume resistivity of 10 ⁵ to 10 ¹³ Ω · cm can be obtained.

In particular, when the drying condition of the solvent is 130 ° C. or higher, the obtained thin film has excellent flexibility, is very tough, and does not crack even when bent. Further, the thin film thus obtained does not dissolve in N-methyl-2-pyrrolidone and further does not dissolve in concentrated sulfuric acid.

Such undoped polyaniline used in the present invention can be obtained by elemental analysis, infrared absorption spectrum, ESR spectrum, laser Raman spectrum, thermogravimetric analysis,
From solubility in a solvent, visible to near-infrared absorption spectrum, (Wherein, m and n represent the molar fractions of the quinone diimine structural unit and the phenylenediamine structural unit in the repeating unit, respectively, and are represented by 0 <m <1, 0 <n <1, and m + n = 1). Having a quinone diimine structural unit and a phenylenediamine structural unit as main repeating units.

By drying the solvent at a temperature of 130 ° C. or higher, the polyaniline constituting the solvent-insoluble thin film also shows substantially the same infrared absorption spectrum as the solvent-soluble polyaniline, and also has elemental analysis, infrared absorption spectrum, and ESR. Spectrum, laser Raman spectrum, thermogravimetric analysis, solubility in solvent, visible to near infrared absorption spectrum, etc.
Although it has a crosslinked structure, it seems to consist of substantially the same repeating unit. However, the film resistivity shows a value about one digit higher when the film is formed.

In the solvent-soluble polymer represented by the general formula,
The values of m and n can be adjusted by oxidizing or reducing the polymer. That is, m can be reduced and n can be increased by reduction. Conversely, if oxidized, m can be increased and n can be reduced. When the quinonediimine structural unit in the polymer is reduced by the reduction of the polymer, the solubility of the polymer in a solvent is enhanced. Also, the viscosity of the solution is lower than before the reduction. Furthermore, the volume resistivity drops to the order of 10 ⁵ Ω · cm.

For the reduction of such a solvent-soluble polymer, hydrazines such as hydrazine hydrate and phenylhydrazine, metal hydrides such as lithium aluminum hydride and lithium borohydride, and hydrogen are preferably used. Organic solvent,
In particular, although soluble in N-methyl-2-pyrrolidone,
Phenylhydrazine is most preferably used because it does not reduce methyl-2-pyrrolidone. On the other hand, the oxidizing agent used for the oxidation of the solvent-soluble polymer is arbitrary as long as it can oxidize the phenylenediamine structural unit in the general formula, but in the reduction half-cell reaction based on the standard hydrogen electrode. An oxidizing agent having a standard electrode potential defined as an electromotive force of 0.3 V or more is particularly preferably used. For example, silver oxide which is a mild oxidizing agent is preferably used.
Oxygen blowing is also useful. As a strong oxidizing agent, for example, potassium permanganate, potassium dichromate, or the like can be used, but it is necessary to prevent the polymer from deteriorating when used. By such an oxidation treatment, m in the above general formula can be increased, and the volume resistivity rises to the order of 10 ¹³ Ω · cm. The volume resistivity of the solvent-soluble polymer thus obtained can be adjusted by oxidation or reduction treatment.

Here, characteristics of the undoped polyaniline obtained from the laser Raman spectrum will be described in comparison with a conventionally known so-called polyaniline.

In general, vibration spectroscopy is a means for obtaining information on vibrations between atoms constituting a substance, and includes infrared spectroscopy and Raman spectroscopy. Infrared spectroscopy is active in vibration modes that result in dipole moment changes, and Raman spectroscopy is active in vibrations that cause polarizability changes. Therefore, the two have a complementary relationship. In general, the vibration mode that appears strongly in infrared spectroscopy is weak in Raman spectroscopy, while the vibration mode that appears strongly in Raman spectroscopy is that in infrared spectroscopy. weak.

An infrared absorption spectrum is obtained by detecting energy absorption between vibrational levels, and a Raman spectrum is obtained when a molecule is excited by light irradiation and then falls to a higher vibrational level in the ground state. It is obtained by detecting the resulting scattered light (Raman scattering). At this time, the vibration energy level can be known from the energy difference of the scattered light with respect to the irradiation light.

Usually, a Raman spectrum is obtained by excitation with visible light from an argon laser or the like. Here, when the sample has an absorption band in the visible region, it is known that a very strong Raman ray can be obtained if the irradiation laser light and the absorption band wavelength match. This phenomenon is called the resonance Raman effect, and according to this, 10 ⁴ to 10 ⁵
Raman lines that are twice as strong can be obtained. According to the resonance Raman effect, information on the chemical structure excited by the wavelength of the irradiated laser light can be obtained with more enhanced information. Therefore, the chemical structure of the sample can be analyzed more accurately by measuring the Raman spectrum while changing the wavelength of the laser light to be irradiated. Such a feature is a feature of Raman spectroscopy that does not exist in infrared spectroscopy.

FIG. 1 shows that N-methyl-
The intrinsic viscosity [η] measured at 30 ° C. in 2-pyrrolidone is 1.
5 is a laser Raman spectrum obtained by irradiating a sample formed into a disk shape of the undoped polyaniline powder used in the present invention at 2 dl / g at an excitation wavelength of 457.9 nm. The assignment of the Raman line is as follows. 1622
And 1591 cm ^-1 are the skeleton stretching vibration of para-substituted benzene, 14
89 and 1479 cm ^-1 correspond to C = C and C of the quinone diimine structure.
= Stretching vibration of N, 1220 cm ^-1 is mixed C-N stretching vibration and C-C stretching vibration, 1185 and 1165 cm ^-1 are plane bending vibration of C-H.

FIG. 2 shows Y. Furukawa et al., Synth. Met., 16 , 189 (1
986) is a laser Raman spectrum obtained by irradiating the undoped polyaniline shown in 986) at an excitation wavelength of 457.9 nm. This polyaniline is placed on a platinum electrode,
It is obtained by electrolytic oxidation polymerization of aniline.

As shown in FIG. 1, in the solvent-soluble undoped polyaniline used in the present invention, the Raman line intensity Ia of the skeleton stretching vibration appearing at a higher wavenumber than 1600 cm ⁻¹ among the skeleton vibrations of the para-substituted benzene. And the ratio Ia / Ib of the Raman line intensity Ib appearing at a wave number lower than 1600 cm ⁻¹ is 1.0 or more. On the other hand, in the conventionally known polyaniline including the polyaniline shown in FIG. 2, the ratio Ia / Ib is smaller than 1.0, including those by chemical oxidative polymerization.

The Raman lines at 1622 and 1591 cm ^-1 are both based on the skeleton stretching vibration of para-substituted benzene. In the polyaniline in the reduced state, since it does not have a quinone diimine structure, a Raman line is generated only at 1621 cm ^-1 , but in the undoped polyaniline having a quinone diimine structure, as described above, the Raman line is generated at 1622 and 1591 cm ^-1 . A line appears. These Raman lines show excitation wavelength dependence as shown in FIG.

As the excitation wavelength is changed from 488.0 nm to 477.9 nm to 457.9 nm on the shorter wavelength side, Ia / Ib changes. That is, at 488.0 nm, Ia / Ib is smaller than 1.0, but 457.9 nm.
Is 1.0 or more, compared to 488.0 nm,
Ia / Ib intensity is reversed. This reversal phenomenon will be explained as follows.

FIG. 4 shows the electronic spectrum of the undoped polyaniline. Since the peak at 647 nm disappears by reducing polyaniline, it is considered to be derived from the quinone diimine structure, and the peak at 334 nm increases in intensity by reducing polyaniline. It seems to be derived from the π-π ^* transition. FIG. 4 shows the Raman excitation wavelength described above. Here, regarding the band of the para-substituted benzene skeleton stretching vibration, the excitation wavelength is 499.
When the wavelength is changed from 0 nm to 457.9 nm on the short wavelength side, 1591 cm ⁻¹
It is considered that the resonance condition of the resonance Raman effect of the band of 1622 cm ^-1 is more advantageous than that of the band of, and the relative intensity changes as described above occur.

Next, in the spectra shown in FIG. 1 and FIG.
Despite the relative intensity of Raman line of 91cm ^-1 and 1622cm ^-1 are the same excitation wavelength (457.9 nm), different from,
It will be explained as follows. That is, N, N-diphenyl-p-phenylenediamine as a model compound having a phenylenediamine structure has a Raman line only at 1617 cm ^-1 , and N, N-diphenyl-p-benzoquine is a model compound having a quinonediimine structure. 1568cm ^-1 and 1621cm for ¹ diimine
^{Since the -1} has a Raman line, as shown in (a) below, the quinone diimine structure and the non-conjugated para-substituted benzene ring have a 1622 cm ^-1 Raman line whose intensity is increased by excitation of short wavelength light. and, as shown in the following (b), para-substituted benzene rings conjugated with quinonediimine structure, 1591cm ^-1 and
It is presumed to have a Raman line of 1622 cm ^-1 .

From the results of elemental analysis, in the undoped polyaniline, the number of quinone diimines and the number of phenylenediamines are considered to be substantially equal.Therefore, the structural chain of the undoped polyaniline has a quinone diimine structure and a phenylenediamine structure. From the linking mode, as shown in (c), an alternating copolymer chain of a quinone diimine structure and a phenylenediamine structure, and as shown in (d), a block copolymer chain of a quinone diimine structure and a phenylenediamine structure. Are classified into two types. In the figure, a para-substituted benzene ring indicated by an arrow indicates a benzene ring that is not conjugated to quinone diimine. In the above-mentioned alternating copolymeric chain, for example, two per octamer chain unit, In a united chain, for example, three per octamer chain unit. If the chain unit is long, the difference in the number of quinone diimines and non-conjugated benzene rings in both is
It becomes even larger. It can be said that this difference appears as a difference in the relative intensity of the Raman line between 1591 cm ^-1 and 1622 cm ^-1 .

For undoped polyaniline, laser
Since the Ia / Ib ratio in the Raman spectrum is 1.0 or more, it is thought that the quinone diimine structure and a large number of non-conjugated benzene rings are contained, thus having the block copolymer-like chain.

The organic solvent solubility of the undoped polyaniline is reasonably explained by having such a block copolymeric chain. Generally, it is known that an imine nitrogen (-N =) in a quinone diimine structure forms a hydrogen bond with a nearby secondary amino group hydrogen (-NH-) (Macromolecules, 21 , 1297 (1988)). The hydrogen bonds between the secondary amino nitrogens are not strong.

Therefore, when the polyaniline has the alternating copolymeric chain, a network having a strong hydrogen bond as shown in (f) is formed. The insolubility of the conventionally known polyaniline in many organic solvents even in the undoped state is considered to be due to the formation of such a network having strong hydrogen bonds.

In contrast, when the polymer chain is the block copolymer-like chain, such as the solvent-soluble undoped polyaniline used in the present invention, the block chains usually have different lengths. As seen in (e), even if the phenylenediamine structure portion and the quinonediimine structure portion are adjacent to each other, many hydrogen bonds cannot be formed, and the solvent penetrates between polymer chains, and the To form a hydrogen bond and dissolve in an organic solvent. If the block chains had exactly the same length in all parts, they would form a network of hydrogen bonds as described above, but the probability of having such a structure is very small,
Usually it can be ignored.

Further, such an interchain interaction is also explained from the CH-in-plane bending vibration of the laser Raman spectrum. The Raman line at 1162 cm ^-1 attributed to the C-H in-plane bending vibration of the undoped polyaniline shown in FIG. 2 shows that the polyaniline is reduced and all imine nitrogen is converted to secondary amino nitrogen. Then, the wave number shifts to 1181 cm ^-1 .

As mentioned above, the undoped polyaniline has a C
There are two Raman lines attributable to the −H in-plane bending vibration, 1165 and 1185 cm ⁻¹ . This 1185cm ^-1 Raman line is
It is not found in the conventionally known undoped polyaniline, and has a value close to 1181 cm ^-1 which is attributed to the C-H in-plane bending vibration in the reduced state.

From these points, it is considered that the solvent-soluble undoped polyaniline used in the present invention has a block copolymer-like chain and has an atmosphere of a reduced structure. This would have high solubility in organic solvents despite its high molecular weight. As described above, the undoped polyaniline used in the present invention is a novel polymer having a different structural chain from the conventionally known polyaniline.

Effect of the Invention The resistance roller according to the present invention, as described above,
Consists of a novel undoped polyaniline. here,
The conductivity of this polyaniline is not affected by moisture and is stable to environmental conditions due to electron conduction, so it has a stable resistance value, and its volume resistivity is in the semiconductor region and the insulator region. 10 ⁵ to 10 ¹³ Ω ・ c
m, and the polyaniline coating has excellent chemical resistance and mechanical strength, so that it can be suitably used, for example, as a resistance roller for a copying machine.

EXAMPLES Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 (Production of Doped Conductive Organic Polymer by Oxidative Polymerization of Aniline) In a 10-liter separable flask equipped with a stirrer, a thermometer and a straight tube adapter, 6000 g of distilled water and 360 ml of 36% hydrochloric acid were placed.
And 400 g (4.295 mol) of aniline were charged in this order to dissolve aniline. Separately, while cooling with ice water, 434 g of 97% concentrated sulfuric acid (4.295 g) was added to 1493 g of distilled water in a beaker.
Mol) were added and mixed to prepare an aqueous sulfuric acid solution. This aqueous sulfuric acid solution was added to the separable flask, and the entire flask was cooled to −4 ° C. in a low-temperature constant temperature bath.

Next, 890 g (4.295 mol) of ammonium peroxodisulfate was added and dissolved in 2293 g of distilled water in a beaker to prepare an oxidizing agent aqueous solution.

The entire flask was cooled in a low-temperature constant temperature bath, and while maintaining the temperature of the reaction mixture at −3 ° C. or lower, the ammonium peroxodisulfate was added to the acidic aqueous solution of the aniline salt from the straight pipe adapter using a tubing pump while stirring. Aqueous solution
The solution was gradually dropped at a rate of 1 ml / min or less. Initially, the colorless and transparent solution turned from green-blue to black-green as the polymerization proceeded, and then a black-green powder was deposited.

During the powder deposition, an increase in temperature is observed in the reaction mixture. In this case, too, in order to obtain a high-molecular-weight polymer according to the present invention, the temperature in the reaction system must be 0 ° C. or lower, preferably −3 ° C. It is important to keep the temperature below ℃. After the powder deposition, the dropping rate of the aqueous solution of ammonium peroxodisulfate may be slightly increased, for example, to about 8 ml / min. However, also in this case, it is necessary to adjust the dropping speed so as to keep the temperature at −3 ° C. or lower while monitoring the temperature of the reaction mixture. After completion of the dropwise addition of the aqueous solution of ammonium peroxodisulfate over a period of 7 hours, stirring was continued for a further 1 hour at a temperature of -3C or lower.

The obtained polymer powder was separated by filtration, washed with water, washed with acetone, and vacuum-dried at room temperature to obtain 430 g of a black-green polymer powder. This was pressed into a disk having a diameter of 13 mm and a thickness of 700 μm, and its electric conductivity was measured by the Van der Pauw method. As a result, it was 14 S / cm.

(Dedoping of conductive organic polymer with ammonia) 350 g of the doped conductive organic polymer powder was added to 2N
The mixture was added to 4 liters of aqueous ammonia, and stirred at 5,000 rpm for 5 hours using an auto homomixer. The mixture turned from black green to bluish purple.

The powder was filtered off with a Buchner funnel and washed repeatedly with distilled water while stirring in a beaker until the filtrate became colorless, followed by washing with acetone until the filtrate became neutral. Thereafter, the powder was vacuum-dried at room temperature for 10 hours to obtain 280 g of a black-brown undoped polymer powder.

This polymer was soluble in N-methyl-2-pyrrolidone, and the solubility was 8 g (7.4%) per 100 g of the same solvent. The intrinsic viscosity [η] measured at 30 ° C. using this as a solvent was 1.23.

The polymer had a solubility of less than 1% in dimethylsulfoxide and dimethylformamide. It did not substantially dissolve in tetrahydrofuran, pyridine, 80% aqueous acetic acid, 60% aqueous formic acid and acetonitrile.

FIG. 1 shows a laser Raman spectrum obtained by irradiating this undoped polyaniline powder into a disk-shaped sample at an excitation wavelength of 457.9 nm. For comparison, Y. Furukawa et al., Synth. Met., 16 , 189 (198
For the undoped polyaniline shown in 6),
FIG. 2 shows a laser Raman spectrum obtained by irradiation at an excitation wavelength of 457.9 nm. This polyaniline is obtained by electrolytic oxidation polymerization of aniline on a platinum electrode.

Also, by changing the wavelength of the laser excitation light,
FIG. 3 shows the result of measuring the Raman spectrum in the range of 00 cm ⁻¹ . As the excitation wavelength is changed from 488.0 nm to 477.9 nm to 457.9 nm on the shorter wavelength side, Ia / Ib changes, and at 457.9 nm, it becomes 1.0 or more, and 488.0 nm
This shows that the Ia / Ib intensity is reversed as compared with the case of FIG.

 FIG. 4 shows an electronic spectrum.

Next, regarding the above-mentioned organic solvent-soluble polyaniline,
GPC using a GPC column for methyl-2-pyrrolidone
Measurements were taken. As the column, three kinds of columns for N-methyl-2-pyrrolidone were used in combination. Also, the eluent
A 0.01 mol / l concentration of lithium bromide in N-methyl-2-pyrrolidone was used. FIG. 5 shows the results of the GPC measurement.

From this result, the organic solvent-soluble polyaniline is:
The number average molecular weight was 23,000 and the weight average molecular weight was 160,000 (both in terms of polystyrene).

Similarly, N-methyl-2-
Organic solvent-soluble polyanilines having different intrinsic viscosities [η] measured at 30 ° C. in pyrrolidone were obtained. For these,
Table 1 shows the intrinsic viscosity [η] and the number average molecular weight and weight average molecular weight determined by GPC.

Reference Example 2 (Preparation of self-supporting film using undoped polyaniline) 5 g of undoped polyaniline obtained in Reference Example 1 was added to N
-Methyl-2-pyrrolidone was added little by little to 95 g, and dissolved at room temperature to obtain a black-blue solution. When this solution was vacuum-filtered with a G3 glass filter, the amount of insolubles remaining on the filter was extremely small. The filter was washed with acetone, and the remaining insolubles were dried and weighed to give 75 mg. Therefore, 98.5% of the polymer was dissolved, and 1.5% of the insoluble matter was dissolved.

The polymer solution thus obtained was cast on a glass plate, wrung with a glass rod, and then N-methyl-2-pyrrolidone was evaporated in a hot air circulating drier. Thereafter, the polymer film was naturally peeled off from the glass plate by immersing the glass plate in cold water, thus obtaining a polymer film having a thickness of 40 μm.

After washing this film with acetone, it was air-dried at room temperature to obtain a film having a copper-colored metallic luster.

Films differ in strength and solubility depending on the drying temperature. When the drying temperature is 100 ° C. or lower, the obtained film dissolves in a small amount in N-methyl-2-pyrrolidone and has relatively low strength. However, the film obtained by heating at a temperature of 130 ° C. or more is very tough and does not dissolve in N-methyl-2-pyrrolidone or other organic solvents. Also, it does not dissolve in concentrated sulfuric acid. Thus, when heated at a high temperature, the polymer molecules are expected to crosslink with each other in the process and become insoluble.

The undoped polyaniline films thus obtained each had a volume resistivity of 10 ¹¹ Ω · cm.

The film did not break even after being bent 10,000 times, and the tensile strength was 850 kg / cm ² .

Reference Example 3 (Preparation of solvent-soluble and solvent-insoluble films made of undoped polyaniline, chemical structure of undoped polyaniline) The undoped polyaniline powder obtained in Reference Example 1 and the undoped polyaniline powder obtained in Reference Example 2 The FT-IR spectra of the solvent-insoluble film by the KBr tablet method are shown in FIGS. 6 and 7, respectively. The spectrum of the insoluble polymer film obtained in Reference Example 2 shows a slight absorption at 1660 cm ^-1 based on the remaining N-methyl-2-pyrrolidone, but the two spectra are almost the same. By heating and drying the solvent after the casting of the polyaniline, the polymer is insolubilized by the crosslinking, but it is recognized that no significant change has occurred in the chemical structure.

FIG. 8 shows the results of thermogravimetric analysis of the solvent-soluble undoped polyaniline powder and the solvent-insoluble film. All have high heat resistance. Considering that the solvent-insoluble film does not decompose to higher temperatures, the fact that it is insoluble in concentrated sulfuric acid indicates that in the solvent-insoluble film, the polymer molecules are crosslinked.

FIG. 9 shows an ESR spectrum. The spin concentration of the soluble polymer is 1.2 × 10 ¹⁸ spin / g, and as the heating temperature increases, the spin concentration increases, indicating that radicals are generated by heating. It is believed that this radical coupling causes the polymer to crosslink and render the heated film insoluble.

Next, the results of elemental analysis of the solvent-soluble undoped polyaniline and the solvent-insolubilized polyaniline are shown below.

Solvent soluble undoped polyaniline C, 77.19; H, 4.76; N, 14.86 (96.81 total) Solvent insolubilized polyaniline (film) C, 78.34; H, 4.99; N, 15.16 (98.49 total) based on, de-doped formula polyaniline solvent-soluble normalized to C12.00 is C _12.00 H
_8.82 N _1.98 , and the composition of the solvent-insolubilized polyaniline is C _12.00 H _9.11 N _1.99 . On the other hand, similarly, C12.00
The quinone diimine structural unit and the phenylenediamine structural unit standardized as follows are respectively as follows.

Quinone diimine structural unit C ₁₂ H ₈ N ₂ phenylenediamine structural unit C ₁₂ H ₁₀ N _{2 Thus} , solvent-soluble undoped polyaniline and solvent-insolubilized polyaniline are both quinone diimine structural unit as described above. It is a polymer having a phenylenediamine structural unit as a main repeating unit.

Example 1 The undoped polyaniline obtained in Reference Example 1 was replaced with N-
A 10% by weight solution was prepared by dissolving in methyl-2-pyrrolidone, applied to a metal roller, and heated at 150 ° C. for 2 hours to form a 20 μm thick layer of undoped polyaniline.
Thus, a resistance roller was obtained.

The volume resistivity of the resistive film in these resistive rollers is 7.
It was 5 × 10 ¹¹ Ω · cm. The resistance value in the thickness direction (electrode area: 1 cm ² ) was 1.5 × 10 ⁹ Ω · cm.

The resistance value in the thickness direction did not change even after the resistance roller was allowed to stand at 80% humidity for 100 hours or in a constant temperature oven at 100 ° C. for 100 hours.

Similarly, resistance rollers having resistance films of various thicknesses were manufactured, and the film thickness and the resistance value in the thickness direction (electrode area 1 cm ² )
And the relationship with the conductivity. The results are shown in FIGS. 10 and 11, respectively. According to the present invention, it is shown that the variation in the resistance value is small.

[Brief description of the drawings]

FIG. 1 is a laser Raman spectrum when undoped solvent-soluble polyaniline used as an electric resistance film in a resistance roller according to the present invention is excited by light having a wavelength of 457.9 nm, and FIG. Raman spectrum when the polyaniline is excited by light having a wavelength of 457.9 nm. FIG. 3 shows the same results obtained when the same undoped solvent-soluble polyaniline as shown in FIG. 1 is excited by light having different excitation wavelengths. Laser Raman spectrum, FIG. 4 shows the N-type of undoped solvent-soluble polyaniline.
3 is an electronic spectrum of a -methyl-2-pyrrolidone solution. FIG. 5 is a graph showing the molecular weight distribution by GPC of undoped solvent-soluble polyaniline used as an electric resistance film in the resistance roller according to the present invention, and FIG. 6 is a KBr tablet method of undoped solvent-soluble polyaniline. FIG. 7 is an FT-IR spectrum of the solvent-insoluble film obtained by casting the undoped solvent-soluble polyaniline by the KBr tablet method, and FIG. 8 is a FT-IR spectrum of the undoped solvent. Thermogravimetric analysis of a film of a solvent-soluble polyaniline and a solvent-insoluble polyaniline. FIG. 9 is a view showing a change in ESR spectrum when the undoped solvent-soluble polyaniline is heated. FIG. 10 is a graph showing the relationship between the thickness of the electric resistance film and the resistance value in the thickness direction (electrode area: 1 cm ² ) in the resistance roller according to the present invention, and FIG. It is a graph which shows the relationship with electrical conductivity.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masao Abe 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nippon Denko Corporation (72) Inventor Minoru Ezoe 1-2-1-2 Shimohozumi, Ibaraki-shi, Osaka (Japanese) JP-A-3-28229 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09K 3/00 G03G 15/08 C08G 73 / 00

Claims (2)

(57) [Claims] 1. A resistance roller in which an electric resistance film made of an organic polymer is provided on a peripheral surface of a metal shaft, wherein the organic polymer has a general formula (Wherein, m and n represent the molar fractions of the quinone diimine structural unit and the phenylenediamine structural unit in the repeating unit, respectively, and are represented by 0 <m <1, 0 <n <1, and m + n = 1). Having a quinone diimine structural unit and a phenylenediamine structural unit as main repeating units, soluble in an organic solvent in an undoped state, and having an intrinsic viscosity (η) of 0.3 in N-methylpyrrolidone measured at 30 ° C.
Of the skeleton vibrations of para-substituted benzene in the laser Raman spectrum obtained by pumping with light of a wavelength of 457.9 nm while being at least 40 dl / g, the Raman line of the skeleton stretching vibration appearing at a higher wavenumber than 1600 cm ^-1 Strength Ia and 1600cm ^-1
Raman intensity of skeleton stretching vibration appearing at lower wavenumber than
A resistance roller, wherein the ratio Ia / Ib of Ib is 1.0 or more. 2. The electric resistance film has a volume resistivity of 10 ⁵ to 10 ¹³ Ω · c.
2. The resistance roller according to claim 1, wherein the resistance roller is in a range of m.