KR20150036998A - Polyamic acid composition for intermediate transfer belt, intermediate transfer belt produced thereof and manufacturing method of intermediate transfer belt - Google Patents

Abstract

The present invention relates to a polyimide intermediate transfer belt having an excellent electric resistance uniformity and long-term durability. More specifically, provided are a semiconductive polyamic acid solution composition containing a carbon black and carbon nanotube as a conductive filler in a polyimide resin, an intermediate transfer belt using the polyamic acid solution composition and having 1×10^8-1×10^13 Ω/cm^2 of a surface resistance at a measured voltage of 500 V and 1×10^6-1×10^13 Ωcm^2·cm^2 of a volume resistance at measured voltage of 100 V, and a manufacturing method thereof.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamic acid solution composition for an intermediate transfer belt, a polyimide intermediate transfer belt using the same, and a process for producing an intermediate transfer belt,

The present invention relates to a polyamic acid solution composition in which carbon black and carbon nanotubes are dispersed as a raw material for a semiconductive polyimide intermediate transfer belt, a semiconductive polyimide intermediate transfer belt using the same, and a process for producing an intermediate transfer belt.

The present invention is applied to an intermediate transfer belt such as an electrophotographic copying machine, a printer, a facsimile, a multifunctional apparatus or a digital printing machine equipped with a color image forming apparatus.

Polyimide resin has excellent heat resistance and mechanical properties and is widely used in electric and electronic parts. And more particularly to a transfer belt, an intermediate transfer belt, a fixing belt, and the like of an image forming apparatus for forming and recording an image by an electrophotographic method.

In recent years, high-speed and high-quality OA machines have become important, and techniques for accurately and precisely controlling the electrical resistance of the intermediate transfer belt have been emerging in order to obtain a high transfer efficiency.

In view of this demand, various attempts have been made to control electric resistance by adding various conductive materials based on polyimide resin.

For example, Japanese Patent Application Laid-Open No. 2-110138 discloses a product comprising an aromatic polyimide matrix and an electrically conductive material, the particle material being uniformly dispersed to form a blend of 10 to 45% by weight of the whole. Japanese Unexamined Patent Application Publication No. 2000-309712 discloses a semi-conductive belt in which 1 to 30 parts by weight of carbon black having one or more volatile components of 2% or more and less than 30% is added to 100 parts by weight of a binder resin . When the amount of the carbon black is more than 30 parts by weight, the formed semiconductive belt tends to be fragile and the mechanical properties inherent to the binder resin are lost, which is undesirable.

Despite the above attempts, it is still a difficult task to precisely control and stabilize the electrical resistance of the polyimide.

The reason is that the polyimide has a high resistance value of itself and a conductive filler having a high conductivity in order to reduce the resistance value, which may result in deterioration in insulation reliability, difficulty in precisely controlling the electric resistance value, The strength of the belt may be lowered and the durability of the belt may be impaired.

In order to solve the above problems, it is an object of the present invention to provide an intermediate transfer belt which is based on a conductive filler and a polyimide resin so as to have durability while stably controlling an electric resistance value in order to obtain a high transfer efficiency as an intermediate transfer belt The purpose.

In order to solve the above-mentioned problems, the present invention provides a process for producing a polymer electrolyte membrane comprising a solvent, a tetracarboxylic acid dianhydride monomer having at least one wholly aromatic skeleton, at least one aromatic diamine monomer, and a solute composed of the tetracarboxylic dianhydride monomer and an aromatic diamine monomer 0.01 to 10 parts by weight of carbon black and 0.01 to 2 parts by weight of carbon nanotubes relative to parts by weight of the polyamic acid solution composition for an intermediate transfer belt.

The present invention also relates to a process for the preparation of a composition comprising 100 parts by weight of a solute comprising a solvent, a tetracarboxylic acid dianhydride monomer having at least one wholly aromatic skeleton, at least one aromatic diamine monomer and the tetracarboxylic acid dianhydride monomer and an aromatic diamine monomer 0.01 to 10 parts by weight of carbon black and 0.01 to 2 parts by weight of carbon nanotubes. The polyamic acid solution is prepared by reacting the tetracarboxylic acid dianhydride monomer with a diamine monomer. The polyamic acid solution has a surface resistance of 1 × 10 ⁸ to 1 × 10 ¹³ Ω / cm 2, and a volume resistance value at a measurement voltage of 10 V is 1 × 10 ⁶ to 1 × 10 ¹³ Ω cm 2 · cm.

The present invention also provides a method for producing a conductive dispersion, comprising: preparing a conductive dispersion by dispersing carbon black and carbon nanotubes in a solvent; Adding a tetracarboxylic acid dianhydride monomer, at least one aromatic diamine monomer, and the conductive dispersion having at least one wholly aromatic skeleton to the solvent and reacting the monomers to obtain a semiconductive polyamic acid solution; Applying the polyamic acid solution to a mold using a dipping method, a centrifugal molding method, or a coating method, and then drying the resin while rotating to remove the solvent and imidizing the solution at a high temperature.

According to another aspect of the present invention, there is provided a method of manufacturing an intermediate transfer belt in which the carbon black and the carbon nanotube are charged in the step of preparing the polyamic acid solution instead of preparing and injecting the conductive dispersion.

According to the present invention, it is possible to obtain a semiconductive polyimide intermediate transfer belt that maintains the charge stability of the charge on the intermediate transfer belt, realizes a very uniform resistance value, and has excellent durability even when used for a long period of time. It is possible to manufacture a color image forming apparatus such as the above.

The present invention relates to a process for the production of a composition comprising 100 parts by weight of a solvent, a tetracarboxylic acid dianhydride monomer having at least one wholly aromatic skeleton, at least one aromatic diamine monomer, and a tetracarboxylic acid dianhydride monomer and an aromatic diamine monomer, 0.01 to 10 parts by weight of carbon nanotubes and 0.01 to 2 parts by weight of carbon nanotubes, a polyamic acid solution composition for an intermediate transfer belt comprising the polyamic acid solution composition and having a surface resistance of 1 × 10 ⁸ to 1 × 10 ¹³ Ω / cm 2, and a volume resistivity at a measurement voltage of 10 V of 1 × 10 ⁶ to 1 × 10 ¹³ Ω cm 2 ㎝, and a method for producing the intermediate transfer belt.

The polyimide resin constituting the intermediate transfer belt of the present invention has the advantages of excellent thermal stability and excellent mechanical and electrical characteristics, while being relatively easily charged. Also, the surface resistance value is higher than the resistance value required as the intermediate transfer belt. Therefore, it is preferable to use a semiconductive polyamic acid solution composition containing a conductive filler.

The semiconductive polyamic acid solution composition for producing the intermediate transfer belt of the present invention can be used as a conductive filler together with carbon black and carbon nanotubes having conductivity.

Examples of the carbon black include furnace black, acetylene black, thermal black, channel black, ketjen black, and the like.

Of these, acetylene black having a high conductivity and a ketjen black having a large specific surface area by oxidation treatment are particularly preferred because they can exert a greater effect when used in combination with carbon nanotubes.

The carbon nanotube may be a single wall carbon nanotube, a doublewall carbon nanotube, or a multiwall carbon nanotube. In the case of single wall or double wall carbon nanotubes, mass production is not active and there is a difficulty in supplying and there is a restriction in use due to high unit price.

The production method of the carbon nanotubes is not particularly limited, but it is more preferable to employ a vapor growth method which is easy to control the diameter of the carbon nanotubes and is capable of mass production.

Therefore, when multi-walled carbon nanotubes are used, conductive carbon nanotubes can be formed with conductive carbon nanotubes in a small amount to provide stable conductivity.

At this time, the diameter of the carbon nanotubes is usually 300 nm or less, preferably 200 nm or less, and the length is usually 50 占 퐉 or less, preferably 20 占 퐉 or less. If the size of the carbon nanotubes is larger than the above range, the dispersibility may be lowered and the mechanical strength and thermal conductivity may be lowered.

The carbon black is preferably used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the solute composed of the tetracarboxylic acid dianhydride monomer and the aromatic diamine monomer.

If the amount of the carbon black is less than 0.01 part by weight, the effect of imparting stable conductivity is insignificant. If the amount of the carbon black is more than 10 parts by weight, the electrical and physical properties of the carbon black affects the physical properties and the mechanical properties are deteriorated.

The multi-walled carbon nanotube is preferably used in an amount of 0.01 to 2 parts by weight based on 100 parts by weight of the solute composed of the tetracarboxylic acid dianhydride monomer and the aromatic diamine monomer.

If the amount of the multi-walled carbon nanotubes is less than 0.01 part by weight, it is difficult to obtain the desired electrical conductivity. When the amount of the multi-walled carbon nanotube is more than 2 parts by weight, the conductivity becomes too high to obtain a desired resistance region.

The addition of carbon black alone can reduce the resistance value. However, when a large amount of carbon black is included in the resistance value of the E8 to E13 area band, which is mainly required in an image forming apparatus, coagulation may occur and it is difficult to stably control the resistance value.

In the present invention, a long multiwalled carbon nanotube having excellent conductivity and a small amount of spherical carbon black having excellent conductivity are mixed to provide a passage structure capable of replenishing between discontinuous conductive materials and moving charges, The intermediate transfer belt may have a substantially uniform and stable resistance value.

In addition, since the conductive filler is added in a small amount compared to the conventional polyimide, the polyimide formed by imidizing the polyamic acid can maintain the inherent mechanical properties of the polyimide, so that the polyimide is stable for long-term use and exhibits excellent durability.

In the semiconductive polyamic acid solution composition for producing the intermediate transfer belt of the present invention, the polyamic acid is obtained by reacting tetra carboxylic acid dianhydride monomer having at least one wholly aromatic skeleton with at least one aromatic diamine monomer in the presence of an organic polar solvent As a polyimide precursor, a method for producing such a polyamic acid solution can be carried out according to a conventional method.

Examples of the tetracarboxylic dianhydride having a wholly aromatic skeleton include pyromellitic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,3,3', 4'-biphenyltetra Naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,5,6-naphthalenetetracarboxylic dianhydride, Or a compound obtained by substituting such an aromatic ring with a lower alkyl group or the like.

Examples of the aromatic diamine include 4,4'-diaminodiphenyl ether, 3,3-diaminodiphenyl ether and 3,4'-diaminodiphenyl ether.

The organic polar solvent is preferably a non-flocculent organic polar solvent such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, Dimethylacetamide, dimethylsulfoxide, hexamethylphosphamide, and 1,3-dimethyl-2-imidazolidinone. One or more of these may be mixed daily.

A method of uniformly dispersing a conductive filler in a polyimide resin in order to realize a uniform resistance value in a finally applied intermediate transfer belt is a method in which a conductive filler is added to a polyamic acid solution as a polyimide precursor in a sand mill, a bead mill, And a method in which a conductive filler is dispersed by a mill or an ultrasonic wave in a solvent used for the synthesis of polyamic acid and then the polyamic acid is synthesized by using this dispersion.

Among them, the method of dispersing the conductive filler by means of milling or ultrasonic wave before the synthesis of the polyamic acid is such that the conductive filler does not penetrate into the polyamic acid because the polyamic acid is synthesized mainly around the conductive filler, so that the conductive filler is uniformly dispersed in the polyamic acid Which is more preferable because it forms a uniform resistance structure.

The average particle diameter of carbon black, which is a conductive filler, is 0.1 to 0.4 占 퐉, and the average particle diameter of carbon nanotubes is 0.1 to 1 占 퐉 in order to achieve uniform dispersion and desired resistance value.

There is no particular limitation on the method of forming the intermediate transfer belt using the semiconductive polyamic acid solution composition of the present invention. The polyamic acid solution containing the conductive filler is formed on the inner or outer peripheral surface of the mold by dipping, And then drying the solution while rotating to remove the solvent, imidizing the solution at a high temperature, and peeling the solution from the mold.

When the solution is applied to the cylindrical mold, it is effective to rotate the mold, since the solution may flow down and cause a thickness variation. As a result, the conductive filler can be uniformly distributed in the formed film.

The heating temperature for imidization may vary depending on the type of the polyimide resin, but is preferably 250 to 400 캜 so that sufficient imidization can be achieved. Further, the defoaming process can be carried out if necessary.

The average thickness of the obtained semiconductive polyimide belt is 60 to 130 탆.

The intermediate transfer belt of the present invention comprises a solvent, a tetracarboxylic acid dianhydride monomer having at least one wholly aromatic skeleton, at least one aromatic diamine monomer, 100 parts by weight of a solute composed of the tetracarboxylic dianhydride monomer and an aromatic diamine monomer 0.01 to 10 parts by weight of carbon black, and 0.01 to 2 parts by weight of carbon nanotubes. The polyamic acid solution is prepared by reacting the tetracarboxylic acid dianhydride monomer with a diamine monomer. The polyamic acid solution has a surface resistance value of 1 × 10 ⁸ to 1 × 10 ¹³ Ω / cm 2 and a volume resistivity at a measurement voltage of 10 V is 1 × 10 ⁶ to 1 × 10 ¹³ Ω cm 2 · cm.

When the polyimide intermediate transfer belt of the present invention is used as an intermediate transfer belt of a color image forming apparatus of an electrophotographic apparatus, it is possible to maintain the charge stability of the charge when used as an intermediate transfer belt by having the surface resistance value and the volume resistance value A very uniform resistance value can be realized and excellent durability can be obtained, so that it is possible to obtain a high-quality transferred image for a long period of time.

Hereinafter, the present invention will be described in detail with reference to Examples. It is to be understood, however, that these examples are for illustrative purposes only and are not to be construed as limiting the scope of the invention as defined by the appended claims. And will be apparent to those skilled in the art to which the present invention pertains.

(Raw materials used in Examples and Comparative Examples)

1. Carbon black

- Ketchen Black EC-600JD (Akzo Nobel)

- # 3030B (Mitsubishi Chemical Corporation)

- General purpose carbon black MA100 (Mitsubishi Chemical Corporation)

2. Carbon nanotubes

- VGCF-X (multiple wall structure, diameter: 15 nm, length: 3 탆, specific gravity: 2.0, Showa Denko KK)

(Test Methods)

1. Surface resistance value

The surface resistance is measured after 10 seconds under the condition of UR Probe and measuring voltage of 500 V in HIRESTA UP MCP-HT450 type (manufactured by Mitsubishi Chemical Analytec Co., Ltd.).

2. Volumetric resistance value

The volume resistivity is measured using the same equipment as above, and after 10 seconds under the condition of measuring voltage 10 V.

3. Resistance Stability

A semi-conductive polyimide intermediate transfer belt was attached to the printer, and 20K sheets of 20K sheets at room temperature (24 DEG C / 55% RH), 20K sheets at high temperature and high humidity (29 DEG C / 85% RH) / 20% RH). Separate the intermediate transfer belt every 10K sheets and measure the resistance. The rate of change in resistance is a value obtained by dividing the Max resistance value by the initial resistance value. When the rate of change of the surface resistance is 4 times or less, excellent print quality can be obtained when the rate of change of the volume resistance is 10 times or less.

4. MIT Test (Endurance Test)

The polyimide tube is cut into a sample having a width of 15 mm and a length of 10 mm to obtain a sample. Measure the number of times until the sample is broken at an angle of 45 ° (both sides of 90 °), a speed of 175 cpm and a load of 200 g. The measurement is carried out five times, and the average value is taken as the measurement value of the MIT test.

5. Durability evaluation

The prepared semiconductive polyimide intermediate transfer belt was attached to a printer, and a notification was made. The state of the belt after the notification was evaluated based on the following criteria.

◎: Notice 250K sheets, belt condition is good

○: Notice 200K pieces ~ 250K pieces Belt Destruction

×: Belt breaking at 200K pages or less

[Example 1]

1.482 g of Ketjenblack EC-600JD and 0.741 g of VGCF-X were added to 111.15 g of N-methyl-2-pyrrolidone (NMP) and uniformly dispersed by ultrasonic dispersion to prepare a conductive dispersion.

60.372 g of 4,4'-diaminodiphenyl ether (ODA) was dissolved in 741.205 g of N-methyl-2-pyrrolidone (NMP) under nitrogen atmosphere to sufficiently dissolve and 113.373 g of the conductive dispersion prepared above was stirred . Then, 87.820 g of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added and stirred for 3 hours to obtain a semiconductive polyamic acid solution.

The polyamic acid solution is spirally coated using a nozzle while rotating a circumferential drum mold made of aluminum having a circularity of 25 m, a diameter of 300 mm and a length of 500 mm. The coated film thus formed was planarized by centrifugal force by rotation, and the coating film of polyimide resin formed by heating stepwise up to 350 占 폚 was cooled and demolded into a tubular shape to obtain a semiconductive polyimide intermediate having an outer diameter of 300 mm and a thickness of 60 占 퐉 A transfer belt was obtained.

[Example 2]

7.410 g of # 3030B and 0.148 g of VGCF-X were added to 377.9 g of N-methyl-2-pyrrolidone (NMP) and uniformly dispersed by ultrasonic dispersion to prepare a conductive dispersion.

To 504.686 g of N-methyl-2-pyrrolidone (NMP), 60.372 g of 4,4'-diaminodiphenyl ether was sufficiently dissolved by stirring in a nitrogen atmosphere, and 385.458 g of the conductive dispersion prepared above was added with stirring. Then, 87.820 g of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride was added and stirred for 3 hours to obtain a semiconductive polyamic acid solution.

Then, a semiconductive polyimide intermediate transfer belt was obtained using the method of Example 1 above.

[Example 3]

To 852.355 g of N-methyl-2-pyrrolidone (NMP) was added 60.372 g of 4,4'-diaminodiphenyl ether and 87.820 g of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride And stirred for 3 hours to obtain a polyamic acid solution. 1.482 g of Ketjen black EC-600JD and 0.741 g of VGCF-X were added to the obtained polyamic acid solution and dispersed in a bead mill for 3 hours to obtain a semiconductive polyamic acid solution.

Then, a semiconductive polyimide intermediate transfer belt was obtained using the method of Example 1 above.

[Comparative Example 1]

To 1007.710 g of N-methyl-2-pyrrolidone (NMP), 60.372 g of 4,4'-diaminodiphenyl ether and 87.820 g of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride were added And stirred for 3 hours to obtain a polyamic acid solution. 29.639 g of MA-100 was added to the obtained polyamic acid solution and dispersed in a bead mill for 3 hours to obtain a semiconductive polyamic acid solution.

Then, a semiconductive polyimide intermediate transfer belt was obtained using the method of Example 1 above.

[Comparative Examples 2 to 4]

A semiconductive polyimide intermediate transfer belt was obtained in the same manner as in Comparative Example 1, except that the composition of Comparative Example 1 was changed as shown in Table 1 below.

Composition chart of the compositions of Examples and Comparative Examples (unit: g) Composition Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 ROOM 60.372 60.372 60.372 60.372 60.372 60.372 60.372 BPDA 87.820 87.820 87.820 87.820 87.820 87.820 87.820 EC-600JD 1.482 1.482 0.015 # 3030B 7.410 17.783 MA100 29.639 22.229 VGCF-X 0.741 0.148 0.741 0.148 3.26 0.015 NMP 852.355 882.586 852.355 1007.710 966.562 859.073 859.157

The results of the measurements of the polyimide intermediate transfer belt obtained in the above Examples and Comparative Examples using the above test method are shown in Tables 2 to 4 below.

Change in surface resistance (unit: Ω / □) division first
Resistance value 10K 20K 30K 40K 50K 60K resistance
Rate of change RT10K RT10K HH10K HH10K LL10K LL10K Example 1 2.10X10 ¹⁰ 4.37X10 ¹⁰ 7.89X10 ¹⁰ 2.31X10 ¹⁰ 3.10X10 ¹⁰ 8.01X10 ¹⁰ 4.18X10 ¹⁰ 3.81 Example 2 2.28X10 ¹⁰ 5.01X10 ¹⁰ 6.98X10 ¹⁰ 3.04X10 ¹⁰ 2.98X10 ¹⁰ 7.87X10 ¹⁰ 4.85X10 ¹⁰ 3.45 Example 3 3.01X10 ¹⁰ 5.54X10 ¹⁰ 9.01X10 ¹⁰ 3.24X10 ¹⁰ 3.45X10 ¹⁰ 1.09X10 ¹⁰ 4.05X10 ¹⁰ 3.62 Comparative Example 1 2.46X10 ¹⁰ 7.89X10 ¹⁰ 2.01X10 ¹¹ 7.87X10 ¹⁰ 6.67X10 ¹⁰ 2.09X10 ¹¹ 8.01X10 ¹⁰ 8.50 Comparative Example 2 2.01X10 ¹⁰ 6.89X10 ¹⁰ 1.50X10 ¹¹ 5.01X10 ¹⁰ 6.08X10 ¹⁰ 1.68X10 ¹¹ 6.00X10 ¹⁰ 8.36 Comparative Example 3 Below range Below range Below range Below range Below range Below range Below range Comparative Example 4 2.06X10 ⁸ 7.09X10 ⁸ 1.07X10 ⁹ 6.05X10 ⁸ 6.88X10 ⁸ 1.08X10 ⁹ 6.87X10 ⁸ 5.24 Rate of change in resistance: maximum resistance value / initial resistance value
RT: room temperature (24 캜 / 55% RH). HH: High temperature and high humidity (29 ℃ / 85% RH), LL: Low temperature and low humidity (10 ℃ / 20% RH)

Change in volume resistance (unit: Ω · cm) division first
Resistance value 10K 20K 30K 40K 50K 60K resistance
Rate of change RT10K RT10K HH10K HH10K LL10K LL10K Example 1 8.67X10 ⁹ 3.06X10 ¹⁰ 4.60X10 ¹⁰ 4.90X10 ¹⁰ 3.98X10 ¹⁰ 4.01X10 ¹⁰ 4.55X10 ¹⁰ 5.65 Example 2 8.80X10 ⁹ 3.06X10 ¹⁰ 4.48X10 ¹⁰ 4.69X10 ¹⁰ 3.68X10 ¹⁰ 4.20X10 ¹⁰ 4.59X10 ¹⁰ 5.32 Example 3 9.01X10 ⁹ 4.54X10 ¹⁰ 5.01X10 ¹⁰ 5.54X10 ¹⁰ 5.55X10 ¹⁰ 4.26X10 ¹⁰ 5.85X10 ¹⁰ 6.49 Comparative Example 1 1.09X10 ¹⁰ 8.89X10 ¹⁰ 2.01X10 ¹¹ 9.87X10 ¹⁰ 9.67X10 ¹⁰ 1.09X10 ¹¹ 9.62X10 ¹⁰ 18.44 Comparative Example 2 1.07X10 ¹⁰ 7.89X10 ¹⁰ 1.50X10 ¹¹ 9.01X10 ¹⁰ 9.28X10 ¹⁰ 1.68X10 ¹¹ 9.20X10 ¹⁰ 15.70 Comparative Example 3 Below range Below range Below range Below range Below range Below range Below range Comparative Example 4 1.01X10 ⁸ 8.09X10 ⁸ 1.06X10 ⁹ 9.05X10 ⁸ 8.88X10 ⁸ 1.18X10 ⁹ 8.87X10 ⁸ 11.68 Rate of change in resistance: maximum resistance value / initial resistance value
RT: room temperature (24 캜 / 55% RH). HH: High temperature and high humidity (29 ℃ / 85% RH), LL: Low temperature and low humidity (10 ℃ / 20% RH)

Endurance and durability division MIT exam (number of times) durability Example 1 > 30000 ◎ Example 2 > 30000 ◎ Example 3 > 30000 ◎ Comparative Example 1 15000 × Comparative Example 2 20000 ○ Comparative Example 3 > 30000 ◎ Comparative Example 4 25000 ○

As shown in Tables 2 to 3, the polyimide intermediate transfer belt using the high conductivity carbon black and the multiwall carbon nanotubes of Examples 1 to 3 had a surface resistance change rate of 4 times or less and a volume The change rate of the resistance is 7 times or less, and the change in the surface resistance and the volume resistance is not so large that the stability is maintained, so that the printing quality is not deteriorated even after long-term printing.

It can be seen that the spherical highly conductive carbon black and the long carbon nanotube stably maintain and maintain the path through which the charge can move, and the resistance becomes very uniform.

In addition, from the MIT test results in Table 4, when the carbon black alone or in combination is used outside the content specified in the present invention, the breakability is lower than that in the examples, whereas in Examples 1 to 3, a small amount of conductive filler is contained It was found that the inherent properties of the polyimide did not deteriorate.

In addition, in the case of Comparative Example 2, when the carbon black was used instead of the high conductivity type carbon nanotubes were used in combination, the content of the filler was increased and the endurance was poor.

In addition, it can be seen from Table 4 that when the compounding amount of the conductive filler in the semiconductive polyamic acid solution is large, the durability of the semiconductive polyimide intermediate transfer belt is deteriorated during long-term use and the belt may be broken. In the case of Comparative Example 3, the desired resistance region could not be obtained by adding carbon nanotubes having an excellent endurance and durability but exceeding the range specified in the present invention.

Claims (8)

A solvent, 0.01 to 10 parts by weight of carbon black per 100 parts by weight of the tetracarboxylic acid dianhydride monomer having at least one wholly aromatic skeleton, at least one aromatic diamine monomer, and the tetracarboxylic acid dianhydride monomer and the aromatic diamine monomer And 0.01 to 2 parts by weight of carbon nanotubes. The method according to claim 1,
Wherein the carbon black is acetylene black or Ketjen black, and the carbon nanotube is a multi-walled carbon nanotube. A solvent, 0.01 to 10 parts by weight of carbon black per 100 parts by weight of the tetracarboxylic acid dianhydride monomer having at least one wholly aromatic skeleton, at least one aromatic diamine monomer, and the tetracarboxylic acid dianhydride monomer and the aromatic diamine monomer And 0.01 to 2 parts by weight of carbon nanotubes. The polyamic acid solution is prepared by reacting the tetracarboxylic acid dianhydride monomer with a diamine monomer. The polyamic acid solution has a surface resistance of 1 × 10 ⁸ to 1 × 10 5 ¹³ Ω / cm 2, and a volume resistance value at a measurement voltage of 10 V is 1 × 10 ⁶ to 1 × 10 ¹³ Ω cm 2 · cm. The method of claim 3,
Wherein the carbon black is acetylene black or Ketjen black, and the carbon nanotubes are multi-wall carbon nanotubes. Dispersing carbon black and carbon nanotubes in a solvent to prepare a conductive dispersion;
Adding a tetracarboxylic acid dianhydride monomer, at least one aromatic diamine monomer, and the conductive dispersion having at least one wholly aromatic skeleton to the solvent and reacting the monomers to obtain a semiconductive polyamic acid solution;
Applying the polyamic acid solution to a mold using a dipping method, a centrifugal molding method, or a coating method, and then drying while rotating to remove the solvent and imidize the solution at a high temperature. Introducing a tetracarboxylic acid dianhydride monomer, at least one aromatic diamine monomer, carbon black, and carbon nanotubes having at least one wholly aromatic skeleton in a solvent and reacting the monomers to obtain a semiconductive polyamic acid solution;
Applying the polyamic acid solution to a mold using a dipping method, a centrifugal molding method, or a coating method, and then drying while rotating to remove the solvent and imidize the solution at a high temperature. The method according to claim 5 or 6,
Wherein the carbon black is acetylene black or Ketjen black, and the carbon nanotubes are multi-wall carbon nanotubes. The method according to claim 5 or 6,
Wherein the carbon black and the carbon nanotube are dispersed in the solvent by milling or ultrasonic waves.