JP2003213131A - Polyimide resin composition, polyimide film, polyimide tubular product and tubular product for electrophotography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyimide resin composition which permits ready adjustment of various medium resistance values stably under ordinary temperature and ordinary humidity conditions to a high temperature and high-humidity conditions, hardly suffers from variation in the resistance value between samples or due to changes in places or added amounts, voltage changes or environmental changes, and can be colored in various colors from transparent to black so as not to exert undesirable influences on image formation even when it is adjacent to an optical instrument, to prepare a polyimide film, and to provide a polyimide tubular product and a tubular product for electrophotography. <P>SOLUTION: The polyimide resin composition comprises 100 pts.wt. of a polyimide resin and 0.1-200 pts.wt. of tin oxide having a volume resistivity of 1×10<SP>3</SP>to 1×10<SP>8</SP>Ω cm, and has a volume resistivity within the range of 1×10<SP>6</SP>to 1×10<SP>15</SP>Ω cm. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide resin composition, a polyimide film, and a polyimide film-like tubular product having an intermediate resistance value without deteriorating the excellent mechanical properties and heat resistance of polyimide. In addition, transfer belts using these, intermediate transfer belts,
The present invention relates to a transfer fixing belt and a tubular article for electrophotography such as a fixing belt.

[0002]

2. Description of the Related Art Polyimide resin has excellent heat resistance,
Taking advantage of its chemical resistance and electrical insulation properties, the film,
Widely used in the form of tubes, belts, molded products, etc. For example, in the form of a film, a base material such as FPC or TAB, an insulating coating such as an electric wire, a tube,
It is used for various purposes such as parts for office automation equipment such as copiers in the form of belts and separating claws and bearings for copiers as molded bodies. Further, in recent years, it has been used in various applications as an adhesive or the like by taking advantage of its characteristics around semiconductors.

However, since the polyimide resin has an excessively high insulating property, the resin is charged during transportation or winding in the manufacture of FPCs and semiconductors, and in recent high-density circuits, dielectric breakdown occurs between wirings due to static electricity. The problem that it has become apparent. On the other hand, the resistance is high to the extent that conduction does not occur, and excellent insulation must be maintained. In this case, the required resistance value is 10 ¹⁰ to 10 ¹⁵
Ω · cm, more preferably 10 ¹⁰ to 10 ¹³ Ω · cm.

In transfer belts, intermediate transfer belts, fixing belts, etc. for electrophotographic applications such as printers, having an intermediate resistance value may be an important quality issue as a function for transferring and fixing toner. Well known. In this case, the required resistance value is 10 ⁶ to 10 ¹³ Ω.
cm. As described above, it is strongly demanded to maintain the insulating property in various fields and control the resistance value to an intermediate value (10 ⁶ to 10 ¹⁵ Ω · cm). Further, the printer includes an optical device, and it is desired that parts used for a portion for performing optical processing and optical color correction be colored, particularly black so as not to reflect light.

In view of these requirements, various attempts have been made to reduce the resistance value by adding various conductive materials to polyimide resin. For example, in Japanese Patent Application Laid-Open No. 2-110138, an aromatic polyimide matrix and a finely divided electrically conductive particle material are contained, and the particle material is uniformly dispersed.
Products present at ˜45% by weight are indicated. In JP-A-63-311263, carbon black is contained in an amount of 5 to 20 wt% and the surface resistance (Ω / □) is 10%.
There is shown an intermediate transfer member for an electrophotographic recording device, which is characterized by comprising an aromatic polyamide film or an aromatic polyimide film in the range of ⁷ ≦ Rs ≦ 10 ¹⁵ . Further, in Japanese Patent No. 2873537, a film made of a composition containing an aromatic polyimide and an electrically conductive inorganic filler, having a volume resistance value of 10 ^-2 to 10 ¹² is disclosed.
It shows a transparent conductive film having an Ω · cm and a total light transmittance of 20% or more.

However, as described above, the method of mixing a filler having a conductive filler such as carbon black, graphite, metal particles or indium oxide with polyimide is often inferior in mechanical properties. Since the filler used in the method (1) has a very low resistivity (1.0 × 10 ³ Ω · cm or less), it is very difficult to control the resistance in the semiconductive region. It was difficult to achieve good reproducibility and reduce in-plane variation.
Further, only those having a large dependency of the resistivity on the measured voltage and the number of added parts were obtained.

Further, in order to improve the drawbacks of such a method, a method of imparting conductivity with a polymer blend of polyaniline and polyimide is disclosed in JP-A-8-259810.
JP-A-8-259709. However, since polyaniline contains ionic conductivity, its resistance value greatly depends on the environment, and further industrial productivity has not been established, and it is very expensive to use as a polymer blend. ing.

Further, in Japanese Patent Laid-Open No. 4-133077,
The average particle size of the main conductive filler is 1 to 50 μm.
And the volume resistivity is 10³-10⁹Large particle size of Ω · cm High resistance
The particles have an average particle size of 0.1 μm as an auxiliary conductive filler.
Volume resistance value ratio is less than 10 ²Small particle size resistance of Ω · cm or less
Anti-particles are dispersed and the volume resistivity is 10^Five-10 ⁹
Semi-conductive resin compound characterized by being in the range of Ω · cm
A composite material is shown.

However, as described above, when large-diameter and high-resistance particles are added, the thickness of the film, tube, etc. is 100 μm.
It is not preferable to obtain a thin molded product because the dielectric breakdown and the voltage dependency of the resistance value increase.

[0010]

In spite of various attempts as described above, it is still very difficult to stably control the resistance value of polyimide to an intermediate value and maintain high insulation. Is.

In particular, when carbon black is added to control the resistance of polyimide, there are the following problems peculiar to polyimide molding. Molding of polyimide is not simple molding such as extrusion method and calender molding by heat melting, but is very complicated involving heating of a precursor polyamic acid solution, solvent drying and imidization reaction. During this drying and reaction, the morphology, polarity, and solubility of the material changes significantly. Especially with chemical cures, the changes are even more dramatic. Carbon black is originally a material that easily aggregates. The carbon black added for controlling the resistance causes agglomeration during the drying and reaction processes, and a slight change in the molding conditions causes a large change in resistance, so that the setting of the molding conditions needs to be very careful. Polyimide resins, especially wholly aromatic polyimide resins, have a very high volume resistance value of 10 ¹⁶ Ω · cm, and a large amount of conductive filler is used as compared with resins having a low volume resistance value such as polyamide and polyvinyl chloride. It was necessary to add to the above, and since it was a large amount, there was a large variation in the volume resistance value due to insufficient kneading and dispersion.

Further, when the resistance is controlled by adding carbon black or conductive particles, these materials have a low resistance value, so that the resistance value greatly changes due to a slight difference in the addition amount or a difference in the dispersion state. There was a problem that the resistance value was different between the samples even if the compositions were exactly the same. Further, when the thickness of the molded body is thin like a belt, partial variation becomes large, which leads to a remarkable decrease in insulation reliability, so that resistance control becomes more difficult.

Further, it is preferable that the belt having a controlled resistance value used as the transfer belt or the intermediate transfer belt has a constant resistance value under any environment. Specifically, the ratio of the resistance value at room temperature and normal humidity to that at high temperature and high humidity is 100 times or less, further 3
It is preferably 0 times or less. However, particularly in a resin material to which a conductive material such as carbon black or conductive particles is added, water permeates into the interface between the conductive material and the resin under high temperature and high humidity, and the electric resistance is significantly reduced. Further, when the base resin absorbs moisture and expands, the dispersed state of the additive changes, and the resistance value changes significantly.

When it is used for a transfer belt or an intermediate transfer belt, it is necessary to control the voltage and current according to the type of image and the environment. If the resistance value varies depending on the voltage, control becomes difficult, and the smaller the voltage dependence of the resistance value, the more preferable. The ratio of the resistance values of 100 V and 1000 V is 100 times or less, more preferably 30 times or less.

Further, since the transfer belt, the intermediate transfer belt and the like are used in the vicinity of the optical processing section, it is desirable that they have a color, especially black. However, as described above, it is difficult to control the resistance value of the carbon-containing belt, and it is difficult to optimize the addition amount.

[0016]

As a result of a comparative study of the effects of various conductive materials in order to solve such problems, the present inventors have found that a specific amount of tin oxide having a specific resistance value is a polyimide resin. By dispersing and mixing in it, it has a medium resistance value, less variation in resistance value and insulation at high temperature and high humidity, less voltage dependence of resistance value, less variation between samples, optical treatment Further, the inventors have found a method for obtaining a polyimide resin composition that can be colored in various colors from transparent to black, which can be used in the optical color compensation section, and have completed the present invention.

That is, the first aspect of the present invention is that the volume resistance value is 1 × 10 ³ to 1 × 1 with respect to 100 parts by weight of the polyimide resin.
A polyimide resin composition containing 0.1 to 300 parts by weight of tin oxide having a resistivity of 0 ⁸ Ω · cm and having a volume resistance value of 1 × 10 ⁶ to 1 × 10 ¹⁵ Ω · cm. Is the content.

More preferably, the volume resistance value of tin oxide is 1 × 10 ⁴ to 1 × 10 ⁷ Ω · cm.

In addition to the tin oxide, one of the resin compositions of the present invention is based on 100 parts by weight of the polyimide resin.
The conductive material may be included in an amount of 0.01 to 40 parts by weight. The conductive material may be one kind or a combination of two or more kinds selected from the group consisting of carbon black, metal and conductive ceramics.

Further, the polyimide resin of the present invention is a reaction-curable linear polyimide resin, which is obtained by adding an acid anhydride and / or a tertiary amine as an imidization accelerator and then heating and baking the same. Good.

Further, in the polyimide resin composition of the present invention, the resistance value R _n at room temperature and normal humidity and the volume resistance value R _{h at} high temperature and high humidity.
The ratio (R _n / R _h ) is preferably in the range of 0.03 to 30, and the ratio of the volume resistance value R _100V when _{100 V} is applied and the volume resistance value R _{1000 V} when 1000 _V is applied (R _100V / R _1000V ) Is preferably in the range of 0.03 to 30.

Further, a second aspect of the present invention provides a polyimide film and a polyimide tubular article made of the above polyimide resin composition.

As one embodiment of the polyimide tubular article of the present invention, there is a polyimide tubular article used for any of a transfer belt, an intermediate transfer belt, a transfix belt or a fixing belt of an electrophotographic apparatus.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The polyimide resin in the present invention refers to any resin having an imide bond in its structure,
This includes not only resins called by general names such as polyetherimide, polyesterimide, and polyamideimide, but also copolymerization systems and blends with other resins. In particular, a reaction-curing linear polyimide resin capable of strongly binding to tin oxide is preferable. Here, the reaction-curable linear polyimide resin refers to a polyimide resin obtained by dehydration ring closure of an amic acid site via a linear polyamic acid as a precursor, and pyromellitic acid diimide A typical example is a polyimide resin obtained by heating, adding a catalyst, or the like to a linear polyamic acid obtained by reacting an anhydride with 4,4′-diaminodiphenyl ether. The linear polyamic acid has a functional group such as a carboxylic acid group or an amino group, and these functional groups strongly interact with tin oxide and can form a strong bond with tin oxide. Mold polyimide resin is preferably used. Further, when an acid anhydride and / or a tertiary amine is used as the imidization accelerator, a product having a strong tear during molding or after molding is obtained as compared with the case of heat curing, and the molding time is significantly shortened. It

As a general polyimide, it is usual to use a diamine compound and tetracarboxylic dianhydride as monomers. Examples of diamine compounds include

[0026]

[Chemical 1]

(Wherein X is the same or different and
-CH₃, -OCH₃, -O (CH ₂)_nCH₃,-
(CH₂)_nCH₃, -CF₃, -OCF₃From the group consisting of
Represents at least one group selected. Also, A is the same.
Or, differently, O, S, C = O, (CH₂)_n, SO₂,
Represents at least one group selected from the group consisting of N = N
You n is an integer of 1 or more. ) Various monomers shown in
You can Also, as tetracarboxylic dianhydride

[0028]

[Chemical 2]

Various monomers shown in the formula (n is an integer of 1 or more) can be used. Various characteristics can be brought out by combining these, and it can be selected according to the situation such as application and processing method.

For example, by using an aromatic diamine containing a large number of bent chains (preferably two or more) and / or having an amino group in the meta position, and by using a tetracarboxylic dianhydride having two or more rings, thermoplasticity is improved. It is possible to provide a resin composition capable of being melt-molded by heating. For example, a combination of 2,2′-bis (4-aminophenoxyphenyl) propane and oxydiphthalic acid dianhydride, or bis (2- (4-aminophenoxy) ethoxy) ethane and 3,3 ′, 4,4 ′ Examples thereof include a combination of benzophenone tetracarboxylic acid dianhydride.

Polyimide usually has a high water absorption rate due to the presence of imide groups, but a resin composition having a relatively low water absorption rate can be prepared by combining a specific monomer.
As an example, there may be mentioned a polyimide using a tetracarboxylic dianhydride having a structure in which a plurality of benzene nuclei are bound by two or more ester bonds. In particular,

[0032]

[Chemical 3]

(In the formula, n is an integer of 1 or more.)

[0034]

[Chemical 4]

[0035]

[Chemical 5]

Examples include acid dianhydrides as shown in: As the diamine compound used in this case, it is preferable to use a relatively long-chain monomer in order to reduce the imide group content. For example, 1,4-bis (4-aminophenoxy) benzene and its bond position isomer, 2,2 '
Examples thereof include -bis (4-aminophenoxyphenyl) propane. However, for both the acid dianhydride and the diamine, the structure having a long chain and a large number of bent chains is also a condition for exhibiting the above-mentioned thermoplasticity, and is not suitable when sufficient heat resistance is required. In this case, long-chain monomers having a linear structure wholly or partially are suitable. For example, as tetracarboxylic dianhydride,

[0037]

[Chemical 6]

An example is a monomer (TMHQ) having a structure shown by. It has been found that this monomer has a structure in which it contains a bent chain and can take a substantially linear conformation as a whole, and it forms a relatively rigid polyimide in spite of the large number of bonds. If this raw material is used, the coefficient of linear expansion is 15 ppm or less and the water absorption rate is 1.5%.
Hereafter, a polyimide resin having a hygroscopic expansion coefficient of 10 ppm or less and having little dimensional change due to heating or moisture absorption can be easily obtained. Further, as the diamine, for example, a structure in which a biphenyl structure or a naphthalene structure is connected by an ether bond can be selected as a relatively rigid structure although it has a long chain. For example, 4,4′-bisaminophenoxybiphenyl and the like. By combining these acid dianhydrides and diamines, it is possible to obtain a polyimide having a relatively low water absorption and having no remarkable thermal softening property. Moreover, not only these monomers but also general-purpose pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, paraphenylenediamine, 4,4'-diaminodiphenyl ether, etc. are appropriately copolymerized to design a polyimide having arbitrary characteristics. It is possible.

The coefficient of linear expansion of polyimide is larger than that of metal such as copper. However, even if the type and composition ratio of the monomers are the same, a resin composition having a relatively small linear expansion coefficient can be obtained by controlling the combination of monomers (sequence control). For example, 4,4′-diaminodiphenyl ether,
Compared to the case of random copolymerization of paraphenylenediamine and pyromellitic dianhydride, 4,4'-diaminodiphenyl ether and pyromellitic dianhydride are reacted in advance, and then the procedure of adding paraphenylenediamine is performed. When taken, a polyimide having a low linear expansion coefficient can be obtained.

In the present invention, since tin oxide is blended with the polyimide resin, higher toughness is required for the polyimide as compared with the case of using the polyimide alone. If the toughness of the polyimide itself is not sufficient, the toughness inevitably decreases due to the addition of tin oxide, and it may not be practically available. In that respect, the most preferable is a polyimide composed of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether. This structure is a well-balanced structure that has both sufficient heat resistance and high toughness and can maintain its characteristics under a wide range of processing conditions.

The tin oxide compounded with the above polyimide resin has a volume resistance value of 1 × 10 ³ to 1 × 10 ⁸ Ω.multidot.
cm tin oxide, preferably having a volume resistance value of 1 × 10 ⁴ to
1 × 10 ⁷ Ω · cm tin oxide is good. Tin oxide, which is usually used for resistance reduction, is usually adjusted to 1 × 10 ³ Ω · cm or less by changing doping and preparation conditions, and it has conductivity similar to carbon black, graphite and metals. is doing. Therefore, when added to the resin, low resistance can be exhibited even if added in a small amount. However, the resin and the low-resistivity tin oxide have a large difference in resistance value, a large resistance variation with respect to the number of added portions and deviation of dispersion, poor voltage dependency, and low insulation. On the other hand, the tin oxide used in the present invention is 1 × 10 ³ to
Since it has a volume resistance value in the medium resistance region of 1 × 10 ⁸ Ω · cm, it can be controlled in the medium resistance region by blending these with a polyimide resin. Further, these substances have a higher resistance than conductive materials such as carbon black, graphite, and metals, and are close to the target volume resistance value, so that the variation in resistance with respect to the number of added parts can be small. In addition, since the resistance value is closer to that of polyimide than carbon black or metal, it is possible to suppress the occurrence of local bias of voltage in the composite material and to reduce the voltage dependence of the resistance value, which is preferable.

The tin oxide used in the present invention has a refractive index of 2.
Since it is 0 or less, it is colorless and transparent, and an arbitrary color tone can be obtained by adding another colorant, which is preferable. When carbon black is blended, a black one can be easily obtained.

The shape of the inorganic material used in the present invention may be granular, needle-like, scale-like, etc., and any structure can be controlled to a medium resistance region. Of these, needle-like and scale-like ones are preferable because they easily come into contact with each other and the resistance can be controlled in the medium resistance region even if the blending amount is small. In addition, it is highly effective in increasing mechanical strength, reducing linear expansion coefficient, and reducing coefficient of hygroscopic expansion, and prevents rupture due to tearing, etc. and dimensional change due to tension, and provides a belt with excellent durability and high dimensional stability and long-term transport characteristics. it can. Also, a belt having high flatness can be obtained. The particle size is 3 μm or less, preferably 2 μm or less, and more preferably 1 μm or less in any shape such as granular, needle-like, and scale-like shapes. The particle size as used herein refers to the average particle size in the case of particles, and the minor axis diameter and thickness in the case of needles and scales, respectively. In a molded body having a small thickness of 100 μm or less, a material having a thickness of more than 3 μm is not preferable because dielectric breakdown occurs due to local aggregation due to poor dispersion. On the other hand, if it is 3 μm or less, the insulating property is not deteriorated even if it is a little aggregated, which is preferable. When granular, the particle size is 3 μm or less, preferably 1 μm
The following are good: If the diameter is out of this range, it becomes difficult to balance the resistance value and the mechanical strength. In the case of needles, those having a minor axis diameter of 3 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less and a major axis diameter of 1 to 50 μm, preferably 2 to 40 μm, and further 3 to 30 μm are used. Is preferred. If the minor axis diameter and the major axis diameter deviate from this range, it becomes difficult to balance the resistance value and the mechanical strength. In the case of a scale, the thickness is 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less, and particularly preferably 0.
5 μm or less and a length of 1 to 50 μm, preferably 2 to
It is preferable to use one having a thickness of 40 μm, more preferably 3 to 30 μm. If the thickness and length deviate from this range, it becomes difficult to balance the insulating property, resistance value, and mechanical strength.

The compounding ratio of these tin oxides is as follows. In the case of granules, the compounding amount is 0.1 to 300 parts by weight, preferably 5 to 280 parts by weight, and more preferably 20 to 250 parts by weight with respect to 100 parts by weight of the polyimide resin. In the case of needle-shaped or scale-shaped tin oxide, the compounding amount is polyimide resin 10
It is 0.1 to 200 parts by weight, preferably 5 to 180 parts by weight, and more preferably 10 to 150 parts by weight with respect to 0 parts by weight. At least one type of each substance is used, but it is also possible to use two or more types of each.

When the content is adjusted within the above range, the change in the resistance value is 3 even if there is a variation in the compounding amount of 5 parts by weight.
It can be suppressed to less than or equal to twice, and the medium resistance region can be controlled without causing a large change in resistance. Further, a darker color can be obtained by adding a colored conductive material such as carbon black or graphite. Further, tin oxide has a large number of functional groups such as hydroxyl groups and active oxygen on the surface, and therefore has excellent dispersibility and has a strong bond with polyimide, so that the tensile elongation is 35% and the tear propagation strength is 250 g / m.
When it is m or more, it is easy to obtain a polyimide resin composition having a retention rate of 50% or more with respect to a filler-unadded product. If needle-shaped tin oxide is used, the tensile elongation is 60% or more, the tear propagation strength is 600 g / mm or more, and the tensile elongation is 80% or more and the tear propagation strength is 120% or more compared to the filler-free product. Have. Even if tin oxide is added, the water absorption rate can be maintained at 5% or less, and the amount of increase in water absorption rate can be suppressed to twice the original water absorption rate of polyimide or less. When it is compounded with another conductive material, the amount of tin oxide added is large, so that the other conductive material can be dispersed and a more uniform dispersed state can be realized. If the amount is less than these blending amounts, the resistance cannot be lowered to the intended medium resistance region. In addition, if it is more than these blending amounts, the mechanical properties will deteriorate,
It is not preferable because it becomes a brittle material.

By appropriately blending these materials, the volume resistance value can be stably 1 × 10 ⁶ to 1 × 10 ¹⁵ Ω · cm,
It is possible to realize an intermediate resistance value with a surface resistance value of 10 ⁶ to 10 ¹⁵ Ω / □. Further, the ratio (Rn / Rh) of the resistance value Rn at room temperature and normal humidity to the volume resistance value Rh at high temperature and high humidity is 0.0.
It can be controlled within the range of 3 to 30, more preferably 0.1 to 10, and a material having excellent environmental stability can be prepared. Also, the volume resistance value R _100V and 100 when applying _100V
Ratio of volume resistance value R _1000V when 0V is applied (R _100V /
R _1000V ) can be controlled within the range of 0.03 to 30, and materials having little voltage dependency can be adjusted. Further, even if the number of added tin oxide parts changes by 5 within the range of the number of added parts, the change in volume resistance is 3 times or less, and a material having little dependency on the number of added parts can be prepared. In addition, it is possible to suppress variations in resistance between samples to less than three times,
It is possible to adjust materials with small variation between samples.

Further, it was difficult to control the volume resistance value of the polyimide resin composition in the medium resistance region of 10 ⁶ to 10 ¹³ Ω · cm by the conventional method, but according to the present invention, it is easily obtained. They provide films and tubing useful as transfer belts, intermediate transfer belts, transfix belts and components of fuser belts in electrophotographic machines.

By adding tin oxide, it has a medium resistance value and a high insulation property, the resistance value has little voltage dependence, the resistance value and the insulation property change little at high temperature and high humidity, and the mechanical strength and the The reason why a polyimide resin composition having excellent dimensional stability and capable of being colored as necessary is obtained is as follows. Also, the tin oxide content is very large compared to the amounts added for normal coloring, resistance control, and strength improvement. This is the reason.

Tin oxide alone is 1 × 10 ³ to 1 × 10 ⁸ Ω.
cm, preferably 1 × 10 ⁴ to 1 × 10 ⁷ Ω · cm, which is different from carbon black, conductive metal and metal ceramics (1 × 10 ⁻⁵ to 1 × 10 ³ Ω · cm).
The resistance value is close to that of polyimide (1 × 10 ¹⁶ Ω · cm). Therefore, the tin oxide-added system does not show a rapid decrease in resistance due to percolation as seen in carbon black, and the resistance changes gently with respect to the amount added. In the carbon black, about 10 to 20 parts by weight is added to 100 parts by weight of the resin in order to control the medium resistance region. However, if the number of added parts changes by about 5 parts by weight with respect to such added parts, The resistance immediately drops 10 to 100 times or more. On the other hand, in the system in which tin oxide is added, the resistance value does not change three times even if the addition amount changes by about 5 parts by weight with respect to the number of addition parts whose resistance is controlled in the medium resistance region. Even if the filler is aggregated or biased during the defoaming or dispersing process, the resistance is not significantly changed. From this, it can be said that tin oxide is a material in which resistance changes little with variations in the amount added.

The fact that tin oxide itself has a medium resistance is considered to play a major role in improving the insulating property and reducing the voltage dependency of the resistance value. When a voltage is applied to the film to measure the resistance of the film made of the polyimide and the conductive material, the voltage is divided between the polyimide and the conductive material. It is believed that the voltage is applied to the portion of the polyimide that has a higher resistance than the conductive material. In particular, comparing the case of adding a low resistance material such as carbon black or a metallic material as a conductive material and a medium resistance material such as tin oxide, the voltage applied to the polyimide is smaller when the medium resistance material is added. Conceivable. As a result, it is considered that the voltage applied to the polyimide is reduced and thus the dielectric breakdown in the polyimide is reduced.

Generally, a high voltage (for example, a thickness of 100 μm) is applied to a resin.
When a voltage of 1 kV or more is applied to m),
The resin approaches dielectric breakdown, and the voltage dependence of the resistance value deteriorates rapidly. That is, a large current flows just before the destruction. From this, it can be considered that the voltage dependency of the resistance value is a phenomenon that occurs when the resin approaches destruction due to the high voltage applied to the resin. However, in a system to which a medium resistance material such as tin oxide is added, it is possible to prevent a high voltage from being locally applied to the polyimide portion which is a resin, as compared with the case where a low resistance material such as carbon black is added. It is possible to improve the voltage dependence of the resistance value.

Since tin oxide partially has a hydroxyl group and active oxygen on the surface, it strongly interacts with the resin during imidization without surface treatment and becomes a strong composite material. For this reason, it becomes a material with strong tear propagation strength and elongation. Even if it is added in a larger amount than the addition amount (usually up to about 30 parts by weight) that is usually added for coloring, resistance control and mechanical property improvement, sufficient mechanical properties , Insulation resistance can be maintained. Further, these strong composite materials can prevent a decrease in resistance value and deterioration of insulation property at high temperature and high humidity for the following reasons. It is considered that the cause of the deterioration of electric characteristics during moisture absorption is that a skin layer made of water is formed at the interface between the resin and the filler due to moisture absorption, and a flow path where electricity easily flows is formed. Is surface-treated with filler or carbon. However, since a material composed of tin oxide and polyimide, particularly a reaction-curable linear polyimide, is a strong composite material, such a skin layer is not formed, and the resistance value and the insulation are not significantly changed.

Therefore, in order to form a strong bond between tin oxide and polyimide, surface treatment may be performed. As the surface treatment agent, a silane-based coupling agent, a titanium-based coupling agent, an aluminum-based coupling agent, an amino acid-based coupling agent, or the like, which can use a coupling agent, can be used. When the resin is a reaction-curable linear polyimide resin, the bond becomes stronger by the surface treatment, but sufficient strength can be obtained without the treatment.

When mixing the polyamic acid and tin oxide, there are mainly the following two methods. The first is a method of polymerizing a polyamic acid by adding tin oxide to a polyamic acid polymerization solvent in advance to prepare a dispersion solution of tin oxide, and then adding a diamine and a dianhydride which are raw materials for the polyamic acid. is there. As another method, there is a method of mixing a polyamic acid obtained by polymerization in advance and a dispersion solution of tin oxide. Whichever method is used, it is necessary to prepare a dispersion solution of tin oxide. Tin oxide has a higher specific gravity than resin and is very heavy, and when tin oxide is added to the solvent, it immediately precipitates. As a result, when mixed with amic acid, tin oxide agglomerates are formed, and irregularities are formed on the surface, or portions where the resistance is locally different are formed.

Therefore, it is advisable to add a dispersant when preparing the tin oxide dispersion solution. Examples of the dispersant include metal salts and surfactants. Particularly preferred are metal salts, such as Li salt, Na salt, K salt, Rb salt and Cs.
One or a combination of two or more selected from the group consisting of salt, Be salt, Mg salt, Ca salt, Sr salt and Ba salt is preferable, and Li salt, Na salt and K salt are preferable. The Li salt is preferably a Li salt having a lattice energy of 1100 or less, and specifically, LiF, LiCl, LiBr, LiI, LiS.
Examples include CN and LiCF ₃ SO ₃ . Na
As the salt, Na salt having a lattice energy of 800 or less is preferable, and specifically, NaF, NaCl, NaBr, NaI,
Examples include NaSCN and NaCF ₃ SO ₃ . The K salt is preferably a K salt having a lattice energy of 800 or less, specifically KF, KCl, KBr, KI, KSC.
Examples thereof include N and KCF ₃ SO ₃ . These metal salts are preferable because the ions are easily dissociated at room temperature and the interaction with tin oxide becomes strong. However, if the lattice energy is too small, the effect of the addition amount becomes too large, so that one having a large lattice energy is preferable. Since these metal salts do not contain organic substances, the resin will not be burnt even during high temperature drying during molding. The dispersant may be blended in a predetermined amount of 1 part by weight or less with respect to 100 parts by weight of the polyimide resin, and 0.01 to 0.1 part by weight or less is sufficient. Generally, in the application of electric wire coating, the addition of a metal salt deteriorates the insulating property, and when it is added to a material having a dielectric constant of 4 or more, the ionic conductivity increases, which is not particularly preferable. Is because polyimide has excellent insulating properties and a dielectric constant of 4 or less,
In the range of the above-mentioned composition, the insulating property and the voltage dependency of the resistance are not deteriorated.

In addition to the tin oxide, a conductive substance may be added to the polyimide resin. However, it is preferable that the color is not blackened upon blending. Examples of other conductive substances include carbon black, graphite, metal powder, metal oxide powder, metal oxide subjected to conductive treatment, and antistatic agent.

As the carbon black blended with the above polyimide resin, various existing carbon blacks can be used as long as they have conductivity, and furnace black, acetylene black, thermal black, channel black and the like can be used. is there. Among them, it is one of the furnace blacks, but particularly when carbon black called Ketjenblack having a large specific surface area is used, the effect is high even when the amount of carbon black blended is small, and when other carbon blacks are used. It has been found that the voltage dependence (the property that the resistance value changes when the voltage changes and does not exhibit the behavior according to Ohm's law) is smaller than that of the above, and it is particularly preferable to use Ketjen black.

As the metal powder to be blended with the above polyimide resin, powders of copper, iron, aluminum, SUS and the like can be mentioned, and as the metal oxide powder, conductive semiconductor ceramics can be mentioned. As the oxide, titanium oxide, potassium titanate, barium sulfate,
An example of the conductive material is mica.

As a mixing ratio of these, a predetermined amount of 40 parts by weight or less is preferably added to 100 parts by weight of the polyimide resin, preferably 10 parts by weight or less, more preferably 4 parts by weight or less. It is good to add. At least one type of each substance is used, but it is also possible to use two or more types of each. If the blending amount is increased, the voltage dependence of the resistance and the insulating property are deteriorated, which is not preferable.
Further, if the blending amount is too small, the effect of using these conductive substances becomes difficult to be exhibited, so 0.01 parts by weight or more, preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, further preferably It is better to blend 5 parts by weight or more.

It is also possible to add other non-conductive inorganic powder to these compounding systems. As the non-conductive filler, for example, alumina, a small-diameter granular material such as silica,
Various substances such as plate-like and scale-like substances such as mica and clay minerals, short fiber-like substances such as barium titanate and potassium titanate or whisker-like substances are used. The non-conductive filler may be added to control other properties such as elastic modulus, and the non-conductive powder may appropriately assist the dispersion of the conductive powder and may cause aggregation of the conductor, etc. In some cases, a stable resistance value can be realized by preventing this.

By appropriately blending them, it is possible to stably realize an intermediate volume resistance value of 1 × 10 ⁶ to 1 × 10 ¹⁵ Ω · cm. Further, the ratio (R _n / R _h ) of the resistance value R _n at room temperature and normal humidity to the volume resistance value R _h at high temperature and high humidity is controlled within a range of 0.03 to 30, and preferably 0.1 to 10. Therefore, a material having excellent environmental stability can be prepared. In addition, the ratio of the volume resistance value R _100V when _100V is applied and the volume resistance value R _1000V when 1000V is applied (R _100V /
R _1000V ) can be controlled within the range of 0.03 to 30, and materials having little voltage dependency can be adjusted. Further, even if the number of added tin oxide parts changes by 5 within the range of the number of added parts, the change in volume resistance is 3 times or less, and a material having little dependency on the number of added parts can be prepared. In addition, it is possible to suppress variations in resistance between samples to less than three times,
It is possible to adjust materials with small variation between samples.

The polyimide having the above composition can be used in various shapes. However, it is particularly difficult for a thin material to have a constant resistance value while maintaining its insulating property. Thus, the above-mentioned composition is particularly effective in a film form in a broad sense such as a film form, a sheet form, a belt form and a tube form, particularly in a form having a thickness of 150 μm or less.

Various methods can be used to disperse the added tin oxide or other conductive material in the polyimide resin.

When the polyimide resin is soluble in a solvent, the powder or a powder obtained by preliminarily dispersing the powder in a solvent is added to the polyimide resin dissolved in the solvent, and the mixture is mixed with a stirring blade or kneaded with a three-roll mill. A machine can be used to promote dispersion. On the contrary, it is also possible to add a solvent-soluble polyimide powder or pellets to a material in which powders are preliminarily dispersed in a solvent and mix them well. As a method of preliminary dispersion, it is effective to add powders to a solvent and sufficiently disperse the mixture with an ultrasonic disperser. In particular, the needle-like powder may be destroyed in shape when it is subjected to an excessive shearing force, so that the method not using three rolls is preferable.

When the polyimide resin is insoluble in a solvent, it is also possible to add the above-mentioned preliminary dispersion to a solution of a polyamic acid which is a precursor of polyimide and carry out mixing and kneading in the same manner.

At this time, it is also possible to use a dispersant for assisting the dispersibility of the solid powder in a range that does not significantly deteriorate the characteristics of the polyimide. When a metal salt is added as a dispersant to the pre-dispersion solution, the state of dispersion is very uniform, and therefore a sufficiently uniform state of dispersion can be achieved by hand stirring. In addition, it is better to add the polyamic acid solution to the pre-dispersion liquid while stirring little by little.
The dispersibility is improved more than the above reverse procedure.

As another method of obtaining particularly good dispersibility, powders are first added to a solvent and sufficiently dispersed by an ultrasonic disperser or the like, and then polyimide (polyamic acid) There is a method in which a diamine compound and an acid dianhydride compound, which are the raw materials of, are added to carry out a polymerization reaction. According to this method, dispersion at a micro level can be maintained well by ultrasonic dispersion, and at the same time, stirring is always performed from the initial solid powder dispersion to the polymerization, so that dispersion at a macro level is achieved. The sex is also very good.

When the solution is a polyimide solution, it can be processed into an arbitrary shape, and then the solvent can be volatilized by heating or by using a reduced pressure depending on the case to obtain a polyimide molded body. Even when the solution is a polyamic acid solution, a polyimide molded body can be obtained by the same steps as in the case of the polyimide solution. In this case, prior to heating, an acid anhydride such as acetic anhydride as a dehydrating agent or a tertiary amine as a catalyst can be used alone or in combination in order to accelerate imidization. However, acid anhydride can not only accelerate the imidization reaction but also cause the main chain of the polyamic acid chain to be cleaved. Therefore, due to the mechanical properties of polyimide, a combination of an acid anhydride and a tertiary amine or a tertiary amine is used. Addition of amine alone is more preferable, and a product having a higher tear propagation strength can be obtained as compared with imidization by heat only. Specifically, the tear propagation strength is 250 g / mm or more, more preferably 5
A product of 00 g / mm or more can be obtained. Also, the addition of a catalyst is very preferable because it can reduce the heating time and suppress the thermal deterioration of tin oxide. In particular, tin oxide causes a change in conductivity due to heating for a long time, so shortening the heating time by adding a catalyst is very important. Further, since the heating time is short, it is possible to suppress the heat deterioration of the resin and the deterioration due to the reaction between the resin and tin oxide, which is preferable. In addition, in the production method by adding a catalyst, the in-plane orientation of the resin proceeds, and when needle-shaped or scaly tin oxide is used, the tin oxide also tends to be oriented in a plane. As a result, the thickness is 10
In the case of a thin molded product having a thickness of 0 μm or less, tin oxide oriented in the thickness direction can be reduced, the electric insulating property can be improved, and the portion where the electrical characteristics deteriorate in the thickness direction due to the moisture absorption of the filler can be reduced, and the humidity dependency of the resistance It is preferable because it can be reduced. Further, the molding time is short, the productivity is remarkably increased, the strength is easily obtained during the production, and the brittleness does not occur during the production.

The following method can be mentioned as an example of a specific method for forming a film and a tubular article.

The resin solution in which the above inorganic components are dispersed is applied onto the endless belt after controlling the thickness by using a T die, a comma coater, a doctor blade or the like. The resin solution is heated and dried by hot air or the like until it has self-supporting property, and then peeled off from the endless belt. A film-like molded product can be obtained by fixing both ends of the peeled-off semi-dried film with a pin or a clip, and sequentially passing them through a high-temperature heating furnace while controlling the length in the width direction. Alternatively, it is applied in the same manner on a continuous sheet-shaped support such as metal, and a film or sheet-shaped polyimide molded body fixed in a sheet is obtained by passing this through a heating furnace, and then supporting. A method of peeling off from the body sheet or removing the support sheet by means such as etching may be adopted.
The easiest method is to obtain a belt or tube by cutting the thus obtained film or sheet-shaped molded product into a predetermined length and width and connecting them to each other in a belt or tube shape. An adhesive, an adhesive tape, or the like can be used for the joining, but this method inevitably causes a step or a break at the joint, which may cause inconvenience depending on the application.

As a method for obtaining a tubular product, a resin solution is applied to the inner surface or the outer surface of a cylindrical mold, and the solvent is volatilized by heating or drying under reduced pressure, and this is heated to the final firing temperature as it is, or The method may be such that it is once peeled off, and finally it is fitted into the outer periphery of another mold for defining the inner diameter and heated to the final firing temperature. In applying the resin solution to the cylindrical mold, it is also effective to rotate the mold in order to reduce the variation in thickness due to the sagging of the resin solution. The final firing temperature needs to be appropriately selected depending on the structure of the polyimide and the heat resistance of the added carbon, but when heating and firing from a polyamic acid state with a non-thermoplastic polyimide, it is generally 350 ° C to 450 ° C.
In the case of a thermoplastic polyimide, a suitable range is between -20 ° C and + 100 ° C with respect to the glass transition temperature of the polyimide.

In order to improve the releasability and transferability of the toner and the cleaning property of the toner, it is advisable to form a fluororesin outermost layer whose conductivity is controlled on the surface of the polyimide tubular material. Examples of the fluororesin include PTFE and PFA, and examples of the additive for controlling conductivity include those listed as the additive for controlling conductivity of polyimide. As a method for forming the outermost layer, coating, laminating films, etc. can be considered, but a method in which these materials are spray-coated as a dispersion is general.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments.

[0074]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited to these examples.

(Physical Property Evaluation Method) Next, the physical property evaluation method of the resin composition will be described. The physical properties were measured by molding a tubular product made of a resin composition and cutting out a film sample.

The resistance values of the film sample and tin oxide were measured as follows. Temperature 10 ℃, Humidity 15% R
Environment with temperature h (LL), environment with temperature 23 ° C and humidity 55% Rh (NN), environment with temperature 30 ° C and humidity 80% Rh (H
H) was left for 24 hours, and the volume resistance value and surface resistance at 100 V were measured using a digital ultra-high resistance / micro ammeter R8340 manufactured by Advantest Corp. and an HR probe manufactured by Mitsubishi Chemical Co., Ltd. under the environment.

The insulation measurement in the film thickness direction was carried out as follows. This film has a temperature of 23 ° C and a humidity of 55%
The sample was left in an Rh environment (NN) for 24 hours, and the insulation was measured under the environment in a YSS type electric breakdown tester manufactured by Yasuda Seiki.

The tensile modulus and tensile elongation of the film sample were measured according to ASTM D882.
The tear propagation strength of the film sample is measured by ASTM
It carried out based on D1938.

Next, examples and comparative examples will be described.

Example 1 As an aromatic diamine 4,
DMF solution of polyamic acid obtained by using 4'-diaminodiphenyl ether and pyromellitic dianhydride as aromatic tetracarboxylic dianhydride (solid content concentration 1
75 g of 8.5% and a solution viscosity of 3,000 poise) was prepared. On the other hand, tin oxide (SH-S:
Nippon Kagaku Sangyo Co., Ltd .: Specific gravity 6.9 g / cm ³ , volume resistance 5 × 10 ^{5 to} 5 × 10 ⁶ Ω · cm, average particle size 1.5 μ
m) A liquid having 12.5 g dispersed therein was prepared.

These polyamic acid solutions and tin oxide dispersions were added and kneaded. Before casting the obtained dope into a tubular film, a solution of 9.03 g / 11.4 g / 15.6 g of acetic anhydride / isoquinoline / DMF was added and mixed, and then cast into a cylindrical SUS at 140 ° C. /
Heat treatment was performed for 360 seconds, 275 ° C./40 seconds, and 400 ° C./93 seconds to obtain a grass-colored polyimide tubular product of about 50 μm. The amount of filler in this tubular product is 90 parts by weight with respect to 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

The polyimide film thus polymerized alone has a linear expansion coefficient of 21 ppm and a hygroscopic expansion coefficient of 16 pp.
m, the tensile elastic modulus was 2.9 GPa, the elongation was 70%, the tear propagation strength was 450 g / mm, and the water absorption rate was 2.5%.

Example 2 A polyimide tubular product was obtained in the same manner as in Example 1 except that 30.45 g of tin oxide was dispersed in 60.9 g of DMF to prepare a liquid. The amount of filler in this tubular product is 220 with respect to 100 parts by weight of polyimide solid content.
It is a department. The characteristic values are shown in Table 1.

Example 3 DMF 21 g was mixed with tin oxide 30.
45 g and carbon black (# MA220: Mitsubishi Chemical Co., Ltd.) 0.55 g were dispersed, except that a liquid was prepared.
A polyimide tubular product was obtained in the same manner as in Example 2. The amount of filler in the tubular product was 224 parts with respect to 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Example 4 A solution of polyamic acid in DMF was used as an aromatic diamine, 3 equivalents of 4,4'-diaminodiphenyl ether were dissolved in DMF, 4 equivalents of PMDA were added, and further 1 equivalent of paraphenylenediamine was added. DMF solution of polymerized polyamic acid (solid concentration 18.
A polyimide tubular product was obtained in the same manner as in Example 2 except that the viscosity was changed to 5% and the solution viscosity was 3,000 poise). The characteristic values are shown in Table 1.

The linear expansion coefficient of the polyimide film thus polymerized alone is 8 ppm, the coefficient of hygroscopic expansion is 9 ppm,
Tensile modulus 4 GPa, elongation 70%, tear propagation strength 4
It was 50 g / mm and the water absorption rate was 2.1%.

Example 5 A DMF solution of polyamic acid was used as an aromatic diamine, and 5 equivalents of 4,4'-diaminodiphenyl ether and 5 equivalents of paraphenylenediamine were added to DMF.
In the same manner as in Example 2, except that 5 equivalents of TMHQ and 5 equivalents of PMDA were further added to polymerize the polyamic acid in DMF solution (solid content concentration 18.5%, solution viscosity 3,000 poise). A tubular product was obtained. The characteristic values are shown in Table 1.

The linear expansion coefficient of the polyimide film thus polymerized alone is 9 ppm, the coefficient of hygroscopic expansion is 5 ppm,
Tensile modulus 6 GPa, elongation 40%, tear propagation strength 4
It was 50 g / mm and the water absorption rate was 1.2%.

The volume resistance values of NN and HH of the polyimide resins of Examples 1 to 5 obtained as described above are 1 × 10 ^11.
〜1 × 10 ¹² Ω ・ cm is adjusted to the medium resistance region,
The insulation was also excellent at 10 kV / mm or more. Further, the ratio of the volume resistance values due to the difference in the number of added parts of tin oxide (5 parts) was 3 times or less, and the dependency of the volume resistance value on the number of added parts was small.
The ratio of the volume resistance values of NN and HH is 30 times or less,
The environmental dependence of the volume resistance value was small. Also, 100V
And the ratio of the volume resistance values measured at 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. In addition, with respect to the five samples prepared by the same operation as above, 10
As a result of measuring the volume resistance value at 0 V, the difference between the maximum value and the minimum value was 3 times or less, and the variation between samples was very small. The variation within the same sample was three times or less, which was very small.

The tensile elastic modulus of the film was superior to that of the non-filled product, and the elongation was kept at 50% or more and the tear propagation strength was kept at 50% or more. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the product with no filler added.

Compared to Example 2, Example 1 was transparent and Example 3 was black.

The tensile modulus increased in the order of Examples 1 to 3, Example 4, and Example 5. This is because the tensile elastic modulus of the base resin increases in this order.

(Comparative Example 1) TMF was added to 21 g of DMF.
Conductive tin oxide coated filler (ET300W: Ishihara Sangyo Co., Ltd .: specific gravity 5.0 g / cm ³ , volume resistance value <1.0E +
A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid in which 10.92 g of 3 Ω · cm and an average particle size of 0.045 μm was dispersed was prepared. The amount of filler in the tubular product was 44 parts based on 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Comparative Example 2 21 g of DMF and 21 g of Sb-doped tin oxide (SN100P: Ishihara Sangyo Co., Ltd .: specific gravity of 6.6 g /
A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid in which 19.73 g of cm ³ , volume resistance value <1.0E + 3Ω · cm, average particle size 0.02 μm) was dispersed was prepared. The amount of filler in this tubular product is 100% of polyimide solid content.
It is 142 parts with respect to parts by weight. The characteristic values are shown in Table 1.

(Comparative Example 3) Carbon black (# 3030B: Mitsubishi Chemical Corporation: <1.0E + 1) was added to 21 g of DMF.
A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid in which 4.17 g of Ω · cm) was dispersed was prepared. The amount of filler in this tubular product was 30 parts based on 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

The volume resistance value of NN in the polyimide resins of Comparative Examples 1 to 3 obtained as described above was adjusted to the target medium resistance region, but with HH, the resistance value was very low and the high voltage was high. In some cases, some of them caused dielectric breakdown. Further, the ratio of the volume resistance values due to the difference in the number of added parts of the filler (5 parts) was 3 times or more, and the dependency of the volume resistance value on the number of added parts was large. The ratio of the volume resistance values of NN and HH is 1
It was 000 times or more, and the environmental dependency of the volume resistance value was very large. Moreover, the ratio of the volume resistance values measured at 100 V and 1000 V was 100 times or more, and the voltage dependency of the volume resistance value was large. In addition, 5 prepared by the same operation as above
As a result of measuring the volume resistance value at 500 V for the sample of the points, the difference between the maximum value and the minimum value is three times or more,
The variation between samples was also very large. The variation within the same sample was three times or more, which was very large.

Further, with the same formulation as in this comparative example, thermal curing (150 ° C./30 minutes, 20
0 ℃ ・ 30 minutes, 300 ℃ ・ 30 minutes, 400 ℃ ・ 30 minutes)
The film prepared in 1 above was extremely brittle both during and after molding, and required a very long molding time as compared with chemical curing.

[0098]

[Table 1]

[0099]

EFFECTS OF THE INVENTION It has a stable medium resistance value from room temperature and normal humidity to high temperature and high humidity, and has little variation in resistance value between samples, change in addition amount, voltage change, environment change, and excellent mechanical properties.
A polyimide resin that can be colored in various colors from transparent to black so that it has excellent antistatic properties due to transport, transferability and fixing properties in electrophotographic machines, and does not adversely affect image formation even if it is adjacent to optical equipment. You can get it.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/16 G03G 15/16 4J002 15/20 101 15/20 101 15/24 15/24 F term (reference) 2H033 AA23 BA11 BE03 BE09 2H071 BA42 DA09 DA12 2H078 AA13 CC06 DD51 DD56 2H200 FA09 GB40 JB45 JB46 JC15 JC16 MA04 MA12 MA13 MA14 MA20 MB04 4F071 AA60 AB03 AB06 AB18 AB29 AE15 AF20 AF02 AF0 AF0 AF0 A012 A016 FB146 FB166 FD010 FD110 FD117 GM00 GP00 GQ00

Claims (12)

[Claims] 1. A body is added to 100 parts by weight of a polyimide resin.
Product resistance is 1 × 10 ³~ 1 x 10⁸Ω · cm tin oxide
Containing 0.1 to 300 parts by weight and having a volume resistance value of 1 × 10
⁶~ 1 x 10¹⁵Characterized by being in the range of Ω · cm
A polyimide resin composition. 2. The volume resistance value of the tin oxide is 1 × 10 ⁴ to
The polyimide resin composition according to claim 1, which is 1 × 10 ⁷ Ω · cm. 3. The polyimide resin composition according to claim 1, wherein the particle size of the tin oxide is 3 μm or less. 4. The composition according to claim 1, further comprising, in addition to the tin oxide, 0.01 to 40 parts by weight of a conductive substance with respect to 100 parts by weight of the polyimide resin. A polyimide resin composition as described in 1. 5. The polyimide tubular article according to claim 4, wherein the conductive substance is one kind or a combination of two or more kinds selected from the group consisting of carbon black, metal, and conductive ceramics. 6. The polyimide resin composition according to claim 1, wherein the polyimide resin is a reaction-curable linear polyimide resin. 7. An acid anhydride and / or as an imidization accelerator.
Alternatively, the polyimide resin composition according to any one of claims 1 to 6, which is obtained by adding a tertiary amine and then baking by heating. 8. The ratio (R _n / R _h ) of the resistance value R _n of the polyimide tubular material at room temperature and normal humidity to the volume resistance value R _h of high temperature and high humidity is in the range of 0.03 to 30. The polyimide resin composition according to any one of claims 1 to 7. 9. The volume resistance value R when 100 V is applied to the polyimide tubular article and the volume resistance value R when 1000 _V is applied.
Polyimide tubular article according to claims 1 _to 8 _1000V ratio (R _100V / R _1000V) is characterized in that in the range of 0.03 to 30. 10. A polyimide film comprising the polyimide resin composition according to claim 1. 11. A polyimide tubular article comprising the polyimide resin composition according to claim 1. 12. The polyimide tubular article according to claim 11, which is used for any one of a transfer belt, an intermediate transfer belt, a transfix belt, and a fixing belt of an electrophotographic apparatus.