TW201402694A - Seamless belt - Google Patents

Abstract

This invention relates to a seamless belt, including a single-layer substrate including a polyimide resin and carbon nanotubes dispersed in the polyimide resin, wherein the polyimide resin is obtained by imidizing an aromatic dianhydride and an aromatic diamine, and the aromatic diamine includes 40 ~ 100 mol% of 1,4-phenylenediamine (1,4-PDA) based on the total amount of the aromatic diamine, and the carbon nanotubes have a diameter of 5 ~ 20 nm and are contained in an amount of 0.1 ~ 2.0 parts by weight based on 100 parts by weight of the polyimide resin.

Description

Seamless belt

The present invention relates to a seamless belt, and more particularly to a seamless belt that can be used as an intermediate conveyor belt for an image forming apparatus.

In general, conveyor belts are used for a wide variety of applications, such as electronic machines, automobiles, and conveyors, which use rotating shafts and electric motors. Conveyor belts have been used as the main components that can replace the transmission. Especially in electronic machines such as copiers, laser printers and fax machines, the function is to print and transfer the formed toner image onto copy paper and transfer paper. Such a conveyor belt can also be used as an intermediate transfer belt. And conveyor belts are used.

Conveyor belts are prone to static electricity during operation, so conveyor belts are required to have antistatic properties. Since the characteristics of the semiconductor have an antistatic function, it can be applied to toner transfer of an electronic machine.

Generally, the conveyor belt is tubular, and the specifications range from 20mm to several meters. However, most conveyor belts, such as flat belts or V-belts, have joints at the joints, so the surface of the joint is not flat, so that the surface characteristics of the joints are different from those of other parts. Electronic machines in particular require the use of evenly flat conveyor belts, especially color laser printers. If the surface of the intermediate transfer belt is not flat, it may damage the photosensitive drum or degrade the quality of the printed image. Moreover, if the joint is slightly twisted, the linearity of the tubular conveyor belt is broken, and the operation is erroneous. This misoperation may cause the conveyor to separate from the drive roller and cause damage to the machine.

Therefore, if the tubular conveyor has no joint, the durability of the belt can be maximized. At the same time, because the surface is flat, it will prevent the conveyor belt or The object touched by the conveyor belt bounces and ensures the linearity of the conveyor belt.

In particular, fixing belts, intermediate transfer belts, etc., which are used in electronic equipment such as printers, copiers, laminating machines, and facsimile machines, should have good stain resistance, heat resistance, heat dissipation, elastic modulus, and antistatic properties. Durability, water resistance, oil repellency and anti-charge characteristics; and in order to be able to transfer toner, the conveyor belt should have an appropriate surface resistivity. In the case where the surface resistivity coefficient ratio is too high or too low, the physical properties of the conveyor belt such as the prevention of charging characteristics, transferability, image characteristics, irregularity and stain resistance are also simultaneously lowered, so that print quality may occur. Bad seriousness.

Conveyor belts such as fixing belts and intermediate transfer belts are made of polycarbonate, polyvinylidene fluoride, polyamide fibers, polyimide resin or rubber during the manufacturing process, and then mixed with conductive additives. The manufacturing process is completed after separation. However, in order to speed up the printing, at the same time, it is necessary to avoid the problem of color overlap or inconsistency during the operation, and thus the conveyor belt can be used repeatedly and can withstand high strength requirements. Moreover, the conveyor belt is also required to be flame retardant, so it is preferable to use a polyimide resin for the material. Moreover, when a conductive additive such as carbon black is used, it is difficult to ensure that the desired conductivity effect is achieved once the amount of addition is not appropriate, and a large amount of dispersant is added to ensure uniformity of surface resistivity, so that the conveyor belt The durability will be reduced.

The following is a conventional technique for a seamless belt comprising a polyimide resin and a conductive filler, which has been continued and disclosed in Korean Patent No. 2011-0032917. The seamless belt contains a polyimine and a polyamide fiber resin. According to the thermogravimetric analysis, when the initial temperature reaches 300 degrees or more and the weight is reduced by 5%, the surface resistivity is 10 ⁷ to 10 ¹³ Ω / Sq. The measurement is performed at any 10 positions on a sample, and the difference between the maximum and minimum values of the surface resistivity is defined as the surface resistivity deviation, whereby the surface resistivity deviation of the seamless belt is 10 or less. However, the seamless belt does not easily regulate the dispersion state of the carbon nanotubes, so if it is used as an intermediate transfer belt, there are problems in durability and the like.

The present invention contemplates the development of a seamless belt that improves durability and has good surface resistivity uniformity.

The seamless belt as mentioned in the preferred embodiment of the present invention comprises a single layer of a polyimide resin comprising a dispersed carbon nanotube in which the polyimine resin is aroma The dianhydride and the aromatic diamine are obtained by oxime imidization. The aromatic diamine contains 1,4-phenylenediamine (1,4-PDA) in an amount of 40 to 100 mol% based on the total amount of the aromatic diamine. The carbon nanotubes have a diameter of 5 to 20 nm and a content of 0.1 to 2.0 parts by weight based on 100 parts by weight of the polyimine resin.

According to the above embodiment, the carbon nanotubes are dispersed in the solvent and then dispersed in the polyimide resin, and the carbon nanotubes dispersed in the solvent may have a particle diameter of 0.02 to 10 μm.

According to the above examples, the aromatic dianhydride may be biphenyltetracarboxylic dianhydride (BPDA).

According to the above examples, the aromatic diamine may comprise selected from the group consisting of 1,3-phenylenediamine (1,3-PDA), 4,4'-methylenediphenylamine (MDA), 4,4'-diaminodi One or more of a combination of phenyl ether (ODA) and 4,4'-oxyphenylenediamine (OPDA).

According to the above embodiment, the surface resistivity of the seamless belt may be from 10 ⁸ to 10 ¹³ Ω/sq.

According to the above embodiment, the common logarithmic value of the surface resistivity deviation of the seamless belt may be 1.0 or less.

According to the above embodiment, the tensile elastic modulus of the seamless belt may be more than 4,000 MPa or more.

According to the above embodiment, the seamless belt may have a folding strength of more than 1000 times.

The seamless belt of the present invention has uniformity of surface resistivity and improves durability, and particularly an intermediate belt which requires reliability, can exhibit its proper physical properties.

1 is a schematic view showing measurement of the diameter of the carbon nanotube of the present invention by a transmission electron microscope (TEM); and FIG. 2 is a schematic view showing the result of measurement of the granularity of the dispersion of the carbon nanotube of the embodiment 1 of the present invention; And Fig. 3 is a schematic view showing the results of measurement of the granularity of the dispersion of the carbon nanotube of Comparative Example 6 of the present invention. Figure.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a seamless belt which is prepared by first preparing a polyaminic acid solution with a dianhydride and a diamine. After dispersing the carbon nanotube in the solution, the semi-conductive ductile polyamic acid is obtained. The solution was prepared by hydrazine imidization.

The above seamless belt comprises a single layer of a polyimide resin and a carbon nanotube dispersed in the polyimide resin. The present invention relates to a seamless belt of the following characteristics, which is obtained by imidating an aromatic dianhydride and an aromatic diamine oxime to obtain a polyimide resin. The aromatic diamine contains 1,4-phenylenediamine (1,4-PDA) in a total amount of 40 to 100 mol%. The carbon nanotube has a diameter of 5 to 20 nm and a content of 0.1 to 2.0 parts by weight based on 100 parts by weight of the polyimine resin.

The term "diameter" as used in the present invention means a cylinder diameter of a carbon nanotube having a cylindrical elongated carbon structure.

Further, the term "particle diameter" as used in the present invention means a tendency to entangle each other in accordance with the length of the original axial direction of the carbon nanotubes, and a size of such agglomerated form in which the van der Waals force agglomerates in a bundle form.

Conventionally, in order to impart conductivity to a seamless belt for an image forming apparatus, a well-known method uses carbon black as a material.

However, in order to make the insulating polyimide resin capable of conductivity, it is necessary to add 10% by weight or more of carbon black to the application in which the carbon powder can be charged. The addition of carbon black in such a large amount has a problem of lowering the good mechanical properties of the polyimide resin.

The conductive material of the present invention uses a carbon nanotube, and after the initial discovery of the carbon nanotube in Sumio Iijima [S. Iijima, Nature Vol. 354, P. 56 (1991), the researchers actively studied this. . Carbon nanotubes have a high modulus of elasticity of 1.0 to 1.8 TPa, which is not possessed by existing materials, and can withstand a high temperature of 2800 ° C in a vacuum state, and the heat transfer coefficient is nearly twice that of diamonds, and the conductivity is 1000 times higher than that of copper. Physical properties. Therefore, in the nano-level electronic devices, electricity Sub-components, nanosensors, optoelectronic components, and high-performance composite materials are highly likely to be used in all fields. The carbon nanotube can be regarded as a cylindrical shape in which the atom in the graphite sheet is rolled up, and its diameter is a very small substance of a nanometer order.

According to the structure, the carbon nanotubes can be divided into one layer of single-walled carbon nanotubes and a plurality of layers of concentric circular multi-walled carbon nanotubes. The diameter of the single-walled carbon nanotubes is 1.0 nm, and depending on the number of walls, the diameter of the multi-walled carbon nanotubes can reach 2 to 100 nm. Single-walled carbon nanotubes are very conductive, but the larger the diameter of a multi-walled carbon nanotube, the weaker the conductivity.

The carbon nanotube of the present invention may have a diameter of 5 to 20 nm, and if the diameter is less than 5 nm, the conductivity is very high, so in order to satisfy the electrical requirements of the semiconductive seamless belt used for the image forming apparatus, few additions should be added. The amount is so difficult to operate, and it is difficult to adjust the surface resistivity deviation of the seamless belt. In addition, when a carbon nanotube having a diameter of more than 20 nm is used, the conductivity of the carbon nanotube itself is weakened, so in order to satisfy the electrical requirements for the seamless belt used in the image forming apparatus, a large amount of carbon nanotubes should be added. It's worse than using carbon black. The diameter of the carbon nanotubes can be measured by a transmission electron microscope (TEM), and the results are shown in Fig. 1.

In the seamless belt according to the embodiment of the present invention, a powdery carbon nanotube is not used in the initial stage of manufacture, and in order to uniformly distribute the polyimine resin, the carbon nanotube may be first added to a solvent to be used in a dispersed state. . At this time, methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, N,N-dimethylformamide, dimethylacetamide, methyl ethyl ketone, ethyl acetate, butyl acetate can be used. An organic solvent such as acetone or toluene is used as a solvent. In particular, it is preferred to use an aprotic dipolar solvent such as N,N-dimethylformamide, dimethylacetamide or N-methylpyrrolidone. At this time, the particle diameter of the carbon nanotubes dispersed in the solvent may be 0.02 to 10 μm, preferably 0.1 to 8 μm. The carbon nanotubes added to the solvent are dispersed by a milling machine and ultrasonic waves, and the particle size becomes smaller after dispersion. When the carbon nanotubes added to the solvent are initially measured before the dispersion, since the carbon nanotubes are not originally present one by one, but the bundles exist, the initial particle diameter is about 1000 μm; the more repeated dispersion, the carbon nanotubes The external force will cause the particle size to become smaller. If the particle diameter of the carbon nanotubes dispersed in the solvent exceeds 10 μm, the larger the agglomerates of the dispersed carbon nanotube particles in the solvent, the weaker the cohesive force of the above resin, and the carbon nanotubes dispersed from the solvent. The position of the particles begins to rupture, which causes a weakening of the folding strength. The solvent may also be dimethylformamide (DMF) at this time.

Further, the content of the carbon nanotubes may be 0.1 to 2.0 parts by weight based on 100 parts by weight of the polyimide resin. If the content of the carbon nanotubes is less than 0.1 parts by weight, the electric resistance ratio is higher than the required value; if the content of the carbon nanotubes exceeds 2.0 parts by weight, there is a problem that the electrical resistance is lower than the required value. That is, since the image forming apparatus uses a seamless function of transporting toner from the drum to the paper, its resistance range should be within the semi-conductive range. However, since the polyimide resin itself is insulative, that is, it is not electrically conductive, a conductive material such as a carbon nanotube can be added to have a semiconducting resistance range, but the content of the carbon nanotube is preferably appropriate.

According to the seamless belt of the present invention, the polyimine resin is obtained by imidating biphenyltetracarboxylic dianhydride and aromatic diamine, and the above aromatic diamine may comprise 40 to 100 moles in total. % of 1,4'-phenylenediamine (1,4-PDA).

When a polyimine resin is produced by using a biphenyltetracarboxylic dianhydride in a dianhydride and 1,4'-phenylenediamine in a diamine to polymerize a polyimide, a rigid and elastic polycondensate can be produced. Imine resin for a seamless belt with good durability. Here, the 1,4'-phenylenediamine has the shortest and hardest structure of the diamine, and the composition having a high tensile modulus can be produced by using the component in an amount of more than 40 mol% based on the total amount of the diamine. band. On the other hand, in addition to the 1,4'-phenylenediamine in the diamine, if 60 mol% or more of other aromatic diamine is used, the tensile modulus of elasticity will become low, and the seamless belt will be elongated during long-time printing. Therefore, it cannot be used for a long time, which reduces durability.

Further, in addition to 1,4-phenylenediamine, the aromatic diamine may be selected from the group consisting of 1,3-phenylenediamine, 4,4'-methylenediphenylamine, 4,4'-diaminodiphenyl ether. And one or more of the combinations of 4,4'-oxyphenylenediamine. The above dianhydride can be used with 1,2,4,5- pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 4,4'- Diphenyl ether tetracarboxylic acid dianhydride (ODPA), 4,4-(hexafluoroisopropene) dicarboxylic anhydride, etc., preferably 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA). Usually the same amount is used for the diamine and the dianhydride. In particular, when biphenyltetracarboxylic dianhydride is used as the dianhydride, the tensile modulus of elasticity and the folding endurance are better than those of other dianhydrides.

In the present invention, the molecular weight of the polyimine resin can be adjusted depending on the polymerization conditions and the type of the dianhydride component and the diamine component, but it is preferably controlled according to the molar ratio of the dianhydride component and the diamine component. Specifically, the component ratio of the dianhydride/diamine is preferably controlled in the range of 100/100 to 90 or 100 to 90/100. However, if the ratio is excessive, the molecular weight of the resin will decrease, which will result in a seamless belt. The mechanical strength is lowered, causing re-agglomeration of the conductive material dispersed in the semi-conductive polylysine, and the surface resistivity of the formed seamless belt is not uniform.

The solvent used in the polymerization of the polyimine resin of the present invention may be N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, N- A guanamine-based polar solvent such as methyl caprolactam is used alone or in combination of two or more.

Further, the seamless belt is preferably manufactured seamlessly, and the manufacturing method thereof is not particularly limited. For example, in the present invention, after the solution is coated with a solution-like polyimide resin on the surface of a cylindrical mold, a seamless belt is produced by heat treatment. The heat treatment is carried out at a temperature of 50 to 400 ° C, and is first pre-baked at 50 to 100 ° C for 10 to 120 minutes to remove the solvent and moisture remaining on the surface. After that, the temperature rise rate of 2~10 °C per minute is maintained, and the final hardening at 350-400 °C completely removes the solvent and moisture present on the surface, and the hydrazine imidization is completed, and a cured seamless belt is produced.

The seamless belt is manufactured to improve its thermal conductivity. If the thickness of the seamless belt is too thin, the strength of the seamless belt may be greatly reduced. During the printing process, the seamless belt may be cracked or twisted due to repeated rotational stress. The appropriate thickness of the seamless belt is 30 to 300 μm.

The seamless belt of the present invention can provide a surface resistivity of 10 ⁸ to 10 ¹³ Ω/sq and a uniform surface resistivity with a deviation of less than 1.0 or less in any region of the seamless belt, and a tensile modulus of elasticity of more than 4000 MPa. As described above, the folding strength is more than 1000 times or more, so that it is a mechanically good seamless belt and can be used as an intermediate transfer belt having durability.

The following detailed description of the embodiments of the present invention is as follows, but the present invention is not limited to the following embodiments.

Example 1

According to the ingredients mentioned in Table 1, a seamless belt was produced in the following manner.

1460 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux cooler, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and 67.7 g of 4,4'-diaminodiphenyl ether (ODA) and 24.4 g of 1,4'-phenylenediamine (PDA) were placed as a diamine under a nitrogen atmosphere. After stirring for about 30 minutes to confirm complete dissolution, put 165.7 g of 3,3', 4, 4'- Biphenyltetracarboxylic dianhydride (BPDA). After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 0.1 part by weight of the carbon nanotubes of the polyamido resin was dispersed in the solution and mixed into the polyamic acid solution. The carbon nanotube used had a diameter of 5 nm, and the carbon nanotubes in the dispersion had a minimum particle diameter of 0.2 μm and a maximum particle diameter of 6 μm. The results of the measurement of the granularity of the carbon nanotubes in the dispersion are shown in Fig. 2.

The above-mentioned semi-conductive polylysine was a black solution in a uniform state and had a viscosity of 200 poise.

On a jointless molding die made of chrome-plated SUS 304, 330 mm in diameter, 5 mm in thickness and 500 mm in width, sprayed with a release agent (KAPIA, Korea) and rotated on a rotary former to prepare the semiconductive polyamine prepared above. The acid solution is uniformly coated through the applicator. Thereafter, the above-mentioned molding metal mold was placed in a drying oven at a rate of 10 ° C /min, and each was set at 100 ° C, 200 ° C, and 300 ° C for 30 minutes. When the hydrazine imidization reaction was completed, the solvent and moisture were completely removed, and after cooling, a thin layer of polyimide was obtained from a SUS belt to produce a seamless belt having a thickness of 65 μm, and the ends of the cut-off seamless belt were formed to have a width of 300 mm.

Example 2

In a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux chiller, and a nitrogen gas inlet, 1290 g of dimethylformamide (DMF) was charged. The temperature was adjusted to 30 ° C and 61.0 g of 1,4'-phenylenediamine (PDA) was placed as a diamine under a nitrogen atmosphere. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 2 parts by weight of the carbon nanotubes of the polyamidene resin were dispersed in the solution and mixed into the polyaminic acid solution. The carbon nanotube used was a carbon nanotube having a diameter of 20 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 100 nm (0.1 μm) and a maximum particle diameter of 7 μm.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

Comparative example 1

1490 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux chiller, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and 79.0 g of 4,4'-diaminodiphenyl ether (ODA) and 18.3 g of 1,4'-phenylenediamine (PDA) were placed in a nitrogen atmosphere. As a diamine. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 0.5 part by weight of the carbon nanotubes containing the polyamidamine resin were dispersed in the solution and mixed into the polyaminic acid solution. The carbon nanotube used was a carbon nanotube having a diameter of 20 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 20 nm (0.02 μm) and a maximum particle diameter of 3 μm.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

Comparative example 2

1460 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux cooler, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and 67.7 g of 4,4'-diaminodiphenyl ether (ODA) and 24.4 g of 1,4'-phenylenediamine (PDA) were placed as a diamine under a nitrogen atmosphere. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 0.1 part by weight of the carbon nanotubes of the polyamido resin was dispersed in the solution and mixed into the polyamic acid solution. The carbon nanotube used was a carbon nanotube having a diameter of 2 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 20 nm (0.02 μm) and a maximum particle diameter of 3 μm.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

Comparative example 3

1460 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux cooler, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and 67.7 g of 4,4'-diaminodiphenyl ether (ODA) and 24.4 g of 1,4'-phenylenediamine (PDA) were placed as a diamine under a nitrogen atmosphere. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 2 parts by weight of the carbon nanotubes of the polyamidene resin were dispersed in the solution and mixed into the polyaminic acid solution. The carbon nanotube used was a carbon nanotube having a diameter of 30 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 150 nm (0.15 μm) and a maximum particle diameter of 10 μm.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

Comparative example 4

1460 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux cooler, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and 67.7 g of 4,4'-diaminodiphenyl ether (ODA) and 24.4 g of 1,4'-phenylenediamine (PDA) were placed as a diamine under a nitrogen atmosphere. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 0.05 part by weight of the carbon nanotubes of the polyamidene resin were dispersed in the solution and mixed into the polyaminic acid solution. The carbon nanotube used was a carbon nanotube having a diameter of 20 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 100 nm (0.1 μm) and a maximum particle diameter of 5 μm.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

Comparative Example 5

1460 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux cooler, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and 67.7 g of 4,4'-diaminodiphenyl ether (ODA) and 24.4 g of 1,4'-phenylenediamine (PDA) were placed as a diamine under a nitrogen atmosphere. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 2.5 parts by weight of the carbon nanotubes of the polyamido resin were dispersed in the solution and mixed into the polyamine solution. The carbon nanotube used was a carbon nanotube having a diameter of 20 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 130 nm (0.13 μm) and a maximum particle diameter of 8 μm.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

Comparative Example 6

1460 g of dimethylformamide (DMF) was charged in a 2 L double-shell reactor equipped with a mechanical stirrer, a reflux cooler, and a nitrogen gas inlet. The temperature was adjusted to 30 ° C and the nitrogen was 67.7 g of 4,4'-diaminodiphenyl ether (ODA) and 24.4 g of 1,4'-phenylenediamine (PDA) were placed as a diamine. After stirring for about 30 minutes to confirm complete dissolution, 165.7 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was charged. After the input, the temperature was maintained while stirring for 3 hours. Thereafter, 1.0 part by weight of the carbon nanotubes of the polyamido resin was dispersed in the solution and mixed into the polyamic acid solution. The carbon nanotube used was a carbon nanotube having a diameter of 20 nm, and the carbon nanotube in the dispersion had a minimum particle diameter of 1.7 μm and a maximum particle diameter of 63 μm. The particle size measurement results of the carbon nanotubes in the dispersion are shown in Fig. 3.

The semiconductive polyphthalic acid to be produced was obtained in the same manner as in Example 1 to obtain a seamless belt.

The surface resistivity, the common logarithm of the surface resistivity deviation, the particle diameter of the carbon nanotube, the tensile elastic modulus, and the folding strength of the seamless belt produced by the methods of the above Examples and Comparative Examples were measured. Table 2 shows.

(1) Surface resistivity

The seamless belt manufactured in the above examples and comparative examples was cut in the width direction, and the thin layer was developed in a two-dimensional form. Choose five points inside and outside the seamless belt. At the selected ten points, Mitsubishi Chemical's Hiresta UP high resistivity meter UR-100 probe was installed and measured at a permit voltage of 100 volts for 10 seconds. Take the average of ten measured values.

(2) Common logarithmic values of surface resistivity deviation

The seamless belt manufactured in the above examples and comparative examples was cut in the width direction, and the thin layer was developed in a two-dimensional form. Choose five points inside and outside the seamless belt. At the selected ten points, Mitsubishi Chemical's Hiresta UP high resistivity meter UR-100 probe was installed and measured at a permit voltage of 100 volts for 10 seconds. Take the common logarithm of the maximum and minimum values of the ten measured values and then find the difference.

(3) Particle size of carbon nanotubes dispersed in the solvent

The dispersed carbon nanotube dispersion was placed on a particle size analyzer of the model Microtrac S3500 (Microtrac, USA) for analysis. Based on the volume average particle diameter.

(4) Tensile modulus of elasticity

Five sheets of horizontal 15 mm by 100 mm longitudinal were taken from the above seamless belt and placed on an Instron 3365 SER test machine. Measured according to ASTM D 882 measurement method.

(5) folding strength

Five sheets of horizontal 15 mm by 100 mm longitudinal were taken from the above seamless belt and placed on an MIT test machine. Measured according to ASTM D 882 measurement method. The measurement was carried out under conditions of R = 2, a bending angle of 135 degrees, and a rotational speed of 175 rpm, and the number of repeated bendings was measured until the sample was broken.

As shown in the results of Table 2 above, according to an embodiment of the present invention, the carbon nanotube has a diameter of 5 to 20 nm, 0.1 to 2.0 parts by weight, a minimum particle diameter of 0.02 μm or more, and a maximum particle diameter of 10 μm or less. The polyimine resin contains 1,4-phenylenediamine in an amount of 40 to 100 mol% of the total amount of the aromatic diamine, and the surface resistivity is 10 ⁸ to 10 ¹³ Ω/sq. The surface resistivity deviation is less than 1.0, the tensile elastic modulus is more than 4,000 MPa, and the folding strength is more than 1000 rpm, so that the durability can be remarkably improved.

Claims (8)

A seamless belt comprising: a single layer of a polyimide resin comprising a dispersed carbon nanotube, wherein the polyimide resin is composed of an aromatic dianhydride and an aromatic diamine Obtained by hydrazine imidation; the aromatic diamine comprises 1,4-phenylenediamine (1,4-PDA) in an amount of 40 to 100 mol% of the total amount of the aromatic diamine; The diameter is 5 to 20 nm, and the content thereof is 0.1 to 2.0 parts by weight based on 100 parts by weight of the polyimine resin. The seamless belt according to claim 1, wherein the carbon nanotube is first dispersed in a solvent and then added to the polyimide resin, and the carbon nanotube dispersed in the solvent is granulated. The diameter system is 0.02~10μm. The seamless belt according to claim 1, wherein the aromatic dianhydride is biphenyltetracarboxylic dianhydride (BPDA). The seamless belt according to claim 1, wherein the aromatic diamine comprises one selected from the group consisting of 1,3-phenylenediamine (1,3-PDA) and 4,4'-methylenediphenylamine (MDA). And one or more of a combination of 4,4'-diaminodiphenyl ether (ODA) and 4,4'-oxyphenylenediamine (OPDA). The seamless belt according to claim 1, wherein the seamless belt has a surface resistivity of 10 ⁸ to 10 ¹³ Ω/sq. The seamless belt according to claim 1, wherein the common logarithmic value of the surface resistivity deviation of the seamless belt is 1.0 or less. The seamless belt according to claim 1, wherein the seamless belt has a tensile elastic modulus of more than 4,000 MPa. The seamless belt according to claim 1, wherein the seamless belt has a folding strength of more than 1000 times.