JP2003082231A - Polyimide resin composition, polyimide film and polyimide tubular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyimide, resin composition, a polyimide film, a polyimide tubular material and a tubular material for electrophotography which can readily be adjusted to various and stable medium resistance values from a normal temperature and normal humidity to a high temperature and high humidity, have slight fluctuation of resistance value between samples and positions and by change of amounts added, voltage change and environmental change and are transparent or nonblack. SOLUTION: This polyimide resin composition comprises 100 parts.wt. of a polyimide resin and 5-200 parts.wt. of a semiconductive inorganic substance having 1×10<3> -1×10<10> Ω.cm volume resistance value and <=3 μm diameter and has 1×10<6> -1×10<15> Ω.cm volume resistance value.

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 tubular product having an intermediate resistance value while keeping the excellent mechanical properties, heat resistance, etc. inherent in polyimide as much as possible. Further, the present invention relates to a tubular article for electrophotography such as a transfer belt, an intermediate transfer belt, a transfer fixing belt and a fixing belt using the polyimide tubular article.

[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, due to its high insulating property, the polyimide resin is charged in the FPC or the periphery of the semiconductor during transportation and winding, and in recent high-density circuits, static electricity causes dielectric breakdown between wirings. 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
・ It is cm. Further, in transfer belts / intermediate transfer belts / fixing belts for electrophotographic applications such as printers, it is well known that having an intermediate resistance value is an important quality issue as a function for transferring and fixing toner. ing. In this case, the required resistance value is 10 ⁶ to 10 ¹³ Ω
・ It is cm. Thus, for the polyimide resin composition, the resistance value is lowered to a certain level in various fields,
And a moderate resistance value (10 ⁶ to 1 that can maintain insulation)
There is a strong demand for control to 0 ¹⁵ Ω · cm).

In view of these requirements, various attempts have been made to reduce the resistance value by adding various conductive substances 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 is 10 ⁷ ≦ Rs ≦.
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 10 ¹⁵ (Ω / □).

However, as mentioned above, polyimide is
Black, graphite, metal particles, indium oxide
Obtained by a method of mixing a conductive filler such as
Molded articles made of the mid resin composition have poor mechanical properties
Is often used in these methods
The filler has a very low resistivity (1.0 × 10 ³
Ω · cm or less), so resistance control in the semi-conductive region is extremely
Difficult, especially resistance with good reproducibility and in-plane variation
Was difficult to reduce. Furthermore, its resistance
Only those with a large dependence on the measured voltage and the number of added parts
I couldn't get it.

Further, Japanese Patent Laid-Open No. 4-133077 discloses
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, adding large particle size and high resistance particles
When added, the thickness of the film, tube, etc. is 100 μm
When obtaining thin molded products, dielectric breakdown and voltage dependence of resistance value
Is large, which is not preferable.

In applications such as IC packages around semiconductors, the product itself must be transparent so that defects can be easily found in the inspection process. For example, TA
In B, it is necessary to perform alignment from the polyimide film side when the adhesive is overheated via the polyimide as the base material and pressure-bonded to the IC chip, and the base material is required to be transparent.

Further, in a transfer belt or an intermediate transfer belt of an electrophotographic apparatus, it is necessary to clean the toner adhered to the belt due to misprinting or conveyance error.
However, it is difficult to confirm the completion of cleaning with the conventional belt that requires the addition of carbon because the color becomes black. Further, it is difficult to visually inspect a black belt for foreign matters and defects during production and to confirm the dispersed state of the conductive material.

Japanese Patent No. 2785537 discloses a film made of a composition containing an aromatic polyimide and an inorganic filler having conductivity, and having a volume resistance value of 10 ^-2.
Although a transparent conductive film characterized by having a total light transmittance of 10 ¹² Ω · cm or more and 20% or more is shown, a decrease in mechanical strength due to addition of an inorganic filler cannot be avoided.

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.

[0011]

In spite of various attempts as described above, it is still a very difficult task to stably control the resistance value of polyimide to an intermediate value.

In particular, when carbon black is added to control the resistance of polyimide, there are the following problems peculiar to polyimide molding. Polyimide molding is not simple molding such as extrusion method and calender molding by heat melting, but is very complicated involving heating of a polyamic acid solution as a precursor, 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 resistance control 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 molding conditions should be set very carefully. 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 low resistance values, so that the resistance values greatly change 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, the resistance control belt used as the transfer belt or the intermediate transfer belt preferably 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 preferably 100 times or less, more preferably 30 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, it becomes difficult to control, and it is more preferable that the resistance value has less voltage dependency. The ratio of the resistance values of 100 V and 1000 V is 100 times or less, more preferably 30 times or less.

Further, in FPC, TAB, etc., it is necessary to visually inspect or optically inspect for foreign matter and position the film, and in the case of a transfer belt, an intermediate transfer belt, etc., it is attached to the belt due to misprinting or conveyance error. Needed toner is cleaned. However, with the carbon-containing belt, the color becomes black, and it is difficult to confirm the completion of cleaning. Further, it is difficult to visually inspect a black belt for foreign matters and defects during production and to confirm the dispersed state of the conductive material.

[0017]

As a result of comparative examination of the effects of various conductive materials in order to solve such problems, the present inventors have found that the volume resistance value is 1 × 10 ³ to 1 × 10 ¹⁰ Ω. By dispersing and mixing a specific amount of semi-conductive inorganic substance of cm in the polyimide resin, it has a medium resistance value, there is little fluctuation of resistance value and insulation at high temperature and high humidity, and resistance value depends on voltage. To obtain a polyimide resin composition that can be made transparent or non-black as needed so that the cleaning property, the dispersion state, the foreign substance defect, etc. can be visually confirmed. A method was found and the present invention was completed.

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.
5 semiconductive inorganic substances with a particle size of 3 μm or less at 0 ¹⁰ Ω · cm
˜200 parts by weight, and volume resistance value of 1 × 10 ⁶ to 1 ×
A polyimide resin composition characterized by being in the range of 10 ¹⁵ Ω · cm.

The volume resistivity of the semiconductive inorganic material is preferably 1 × 10 ⁴ to 1 × 10 ⁹ Ω · cm, and the particle size is 2 μm.
It is the following.

In one embodiment, the semiconductive inorganic material is an inorganic material coated with a conductive material, preferably barium sulfate, aluminum borate, mica, silica, glass, alumina, zinc oxide, titanium oxide. , Potassium titanate, wollastonite, calcium carbonate, talc, and at least one inorganic material selected from the group consisting of kaolin, and more preferably at least one selected from the group consisting of barium sulfate, aluminum borate, and mica. It is one kind of inorganic substance.

The conductive material is preferably I
TO (tin-doped indium oxide), ATO (antimony-doped tin oxide), NTO (niobium-doped tin oxide), TT
It is at least one conductive material selected from the group consisting of O (tantalum-doped tin oxide), FTO (fluoride-doped tin oxide) and TO (tin oxide), and more preferably ITO (tin-doped indium oxide). At least one conductive material selected from the group consisting of ATO (antimony-doped tin oxide), NTO (niobium-doped tin oxide), TTO (tantalum-doped tin oxide), and FTO (fluoride-doped tin oxide), The dope content is 10% by weight or less based on the conductive substance.

These conductive substances are preferably conductive substances obtained by heat treatment in an oxidizing atmosphere.

Further, one of the resin compositions of the present invention may contain 0.01 to 20 parts by weight of a conductive material with respect to 100 parts by weight of the polyimide resin, in addition to the semiconductive inorganic material.

As a preferred embodiment of the present invention,
Volume resistivity ¹ × 10 ⁶ ~1 × 10 1 within the range of ³ Omega · cm, or volume resistivity ^{1 × 10 9 ~1 × 10 15} Ω
-The above-mentioned polyimide resin composition having a total light transmittance of 50% or more in the range of cm.

Furthermore, the second aspect of the present invention provides a polyimide film and a polyimide tubular article made of the above-mentioned 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.

[0027]

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-curable linear polyimide resin that can strongly bond with a semiconductive inorganic material is preferable. Here, the reaction-curable linear polyimide resin refers to a polyimide resin obtained by subjecting a linear polyamic acid as a precursor to dehydration ring closure of an amic acid site, and pyromellitic acid. A typical example is a polyimide resin obtained by heating, adding a catalyst, or the like to a linear polyamic acid obtained by reacting a dianhydride 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 can strongly interact with the semiconductive inorganic substance and form a strong bond with the semiconductive inorganic substance. Therefore, a reaction-curable polyimide resin is preferably used.

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

[0029]

[Chemical 1] (In the formula, X is the same or different, and halogen, -C
H₃, -OCH₃, -O (CH ₂)_nCH₃,-(CH₂)_n
CH₃, -CF₃, -OCF₃A few selected from the group consisting of
At least represents a kind of group. A is the same or different
, O, S, C = O, (CH₂)_n, SO₂, From N = N
Represents at least one group selected from the group consisting of n is 1
Greater than or equal to an integer. ) Various monomers shown in
It Also, as tetracarboxylic dianhydride

[0030]

[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 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.

Further, the polyimide usually has a high water absorption rate due to the presence of the imide group, 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,

[0033]

[Chemical 3] (In the formula, n is an integer of 1 or more.)

[0034]

[Chemical 4]

[0035]

[Chemical 5] An acid dianhydride as shown in is mentioned. 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, its bond position isomer, 2,2'-bis (4-aminophenoxyphenyl) propane, etc. can be mentioned. 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,

[0036]

[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. By using this raw material, it is possible to easily obtain a polyimide resin having a linear expansion coefficient of 15 ppm or less, a water absorption rate of 1.5% or less, and a hygroscopic expansion coefficient of 10 ppm or less, which has a small dimensional change due to heating or moisture absorption. 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. In addition to these monomers, general-purpose pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, paraphenylenediamine, 4,4
By appropriately copolymerizing ′ -diaminodiphenyl ether or the like, a polyimide having arbitrary characteristics can be designed.

In the present invention, the polyimide resin is mixed with a semiconductive inorganic substance, and therefore, 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 blending of the inorganic substance, and it may not be practically applicable. In that respect, the most preferable is a polyimide composed of pyromellitic dianhydride and 4,4'-diaminodiphenyl ether. This structure is
It has 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 semi-conductive inorganic material blended with the above polyimide resin has a volume resistance value of 1 × 10 ³ to 1 ×.
A semiconductive inorganic substance having a resistivity of 10 ¹⁰ Ω · cm, preferably a semiconductive inorganic substance having a volume resistance value of 1 × 10 ⁴ to 1 × 10 ⁹ Ω · cm is preferable. Furthermore, this semiconductive inorganic material may be an inorganic material coated with a conductive material. This is because various resistance materials can be adjusted depending on the type, amount, and forming method of the conductive substance to be coated. For example, materials such as potassium titanate, tin oxide, and zinc oxide have only specific resistance values, and when these are used to control various resistances, two or more kinds of materials having different resistance values are used. It is necessary to take a method such as mixing the filler, or to change the number of parts to be mixed, which requires a great deal of labor to control the dispersibility and adjust the composition according to each filler, and to change the mixing amount The characteristics may differ. However, if the material coated with the conductive substance of the present invention is used, a material having various resistances can be easily prepared from a single material, and the conductivity can be controlled without changing the mechanical characteristics or dispersibility. Therefore, it is possible to prepare polyimide resins having different resistance values even with the same compounding amount, and it is possible to easily obtain materials having exactly the same mechanical properties and dispersibility but different volume resistance values. Further, since the basic characteristics such as mechanical characteristics and dispersibility of the semiconductive inorganic material are the same, the cleaning work and the switching work by changing the type become very easy.
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.

Examples of the inorganic material (base particles) used in the present invention include ceramic materials such as metals, metal oxides, metal carbides and metal nitrides, and metal salts. For example, zinc, zinc oxide, aluminum, alumina, aluminum hydroxide, calcium, calcium carbonate, silver, chromium oxide, silicon, silica, glass, titanium oxide, potassium titanate, other alkali metal titanates, aluminum borate, iron, Iron oxide, copper, copper oxide, barium carbonate, barium sulfate, barium hydroxide, barium carbonate, magnesium, magnesium hydroxide, silicon carbide, tungsten carbide, titanium carbide, aluminum nitride, silicon nitride, germanium nitride, tantalum nitride, titanium nitride , Boron nitride, mica, talc, wollastonite, talc, kaolin, clay minerals and the like.

Zinc oxide, titanium oxide and potassium titanate have a high refractive index and a high hiding rate. Especially titanium oxide
It has a refractive index of 2.5 or more, a high concealment ratio, and has the property of making the material white. When added to polyimide, the material becomes yellow. Further, even if another black additive such as carbon black or an organic pigment is added, it does not become black easily. As a result, the belt made of these materials makes it easy to check the dirt state at the time of toner cleaning, easily inspects for foreign matters and defects at the time of making, confirms the dispersed state, and easily forms markings. In addition, it is possible to immediately identify the location of the dielectric breakdown and the surface scratch. Further, in the case of forming a tin oxide film, titanium oxide has the same crystal structure as that of the substance of the coating layer, so that a tin oxide film having excellent adhesion is formed, and as a result, the conductive film has a conductive property. In addition, when the conductive filler is added to the resin or the like, the tin oxide coating that has been coated on the surface of the conductive filler does not peel off when the conductive filler is mixed, resulting in loss of conductivity.

On the other hand, barium sulfate, aluminum borate and mica are preferable because they have a refractive index close to that of the resin and therefore are less likely to be mixed with the resin to impair transparency and not colored. It is preferable to add another colorant because an arbitrary color tone can be obtained. Further, silica, glass, alumina, wollastonite, calcium carbonate, talc, and kaolin also have a relatively low refractive index, and their transparency is not easily impaired even when added to a resin.

In order to balance the transparency and the concealing property appropriately, a semiconducting inorganic substance having an excellent concealing property and a semiconducting inorganic substance having an excellent transparency may be mixed.

The shape of the semiconductive inorganic material used in the present invention may be granular, needle-like, plate-like or the like, and any structure can be controlled to a medium resistance region. Among them, needle-like or plate-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. Whether it is granular, needle-shaped or plate-shaped, the particle size is 3 μm or less, preferably 2
It is less than or equal to μm, and more preferably less than or equal to 1 μm. 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 plates, 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. In the case of particles, the particle size is 3 μm or less, preferably 1 μm or less. 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, the minor axis diameter is 3μ
m or less, preferably 1 μm or less, more preferably 0.
5 μm or less and major axis diameter of 50 μm or less, preferably 1
It is preferable to use one having a thickness of 0 μm or less, further preferably 1 μm or less. 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 plate, a plate having a thickness of 3 μm or less, preferably 2 μm or less, more preferably 1 μm or less, particularly preferably 0.5 μm or less and a length of 50 μm or less, preferably 10 μm or less, further 1 μm or less is used. Is preferred. If the thickness and length deviate from this range, it becomes difficult to balance the insulating property, resistance value, and mechanical strength.

In particular, as the acicular inorganic substance, it is preferable to use titanium oxide whiskers, alkali metal titanate whiskers, aluminum borate whiskers and the like. Further, as the plate-like inorganic substance, it is preferable to use mica, talc, clay mineral or the like. In particular, titanium oxide or alkali metal titanate may be used as an inorganic substance to enhance the hiding property, and aluminum borate, mica, talc or clay mineral may be used to enhance transparency. Aluminum borate is preferable because it has a low specific gravity and can effectively reduce the resistance even if the addition amount is small. In addition, it has better acid resistance than alkali metal titanate, and when coating a conductive substance, the alkali component does not elute due to acid, does not break, miniaturize, or become porous, and is coated with a small amount of a conductive substance. Is possible, which is preferable.

One method for preparing an inorganic material coated with a conductive substance will be described below by taking the method for forming a conductive coating layer of tin oxide on the above-mentioned base particles as an example.

First, in order to form a coating layer of a hydrate of tin oxide on the base particles, for example, an aqueous suspension of the base particles is prepared, and the previously water-soluble suspension is mixed with a metal solution of tin. , An alkali or an acid is added to precipitate a hydrate of tin oxide on the base particles to form a coating layer. The above-mentioned coating treatment may be carried out by separately adding a metal salt solution of tin and an alkali or an acid to deposit a precipitate, or may be added in parallel to deposit a precipitate. Further, when the suspension is heated at 40 to 90 ° C. or when the precipitation is gradually deposited while controlling the addition treatment rate, a dense coating layer is easily formed, which is more preferable. It can bring results. Examples of the tin metal salt solution include aqueous solutions of tin chloride, sulfate, nitrate, etc., and stannate salts such as sodium stannate, potassium stannate, etc. For example, an aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, ammonia or the like, ammonia gas or the like, and hydrochloric acid, sulfuric acid, nitric acid or the like can be used as the acid. The coating amount is 0.1 to 30%, preferably 1 to 20% as SnO ₂ based on the weight of the base particles. If the coating amount is less than the above range, the desired conductive performance may not be obtained, and if it is too large, unfavorable results such as a decrease in whiteness may be brought about. In the present invention, the suspension obtained by coating the surface of the substrate particles with a hydrate of tin oxide is filtered and washed, and then the treated cake is separated and collected and, if necessary, dried and pulverized, Heat treatment is performed in an oxidizing atmosphere or in an oxidizing atmosphere to obtain a semiconductive inorganic material having desired conductivity. The gas used for maintaining the non-oxidizing atmosphere includes an inert gas and a reducing gas, and the inert gas includes, for example, nitrogen and argon, and the reducing gas includes, for example, Hydrogen, ammonia, carbon monoxide and the like can be used. In particular, when the heat treatment is performed in an inert gas atmosphere, it is more desirable in terms of treatment operation and economical efficiency. As the gas used for maintaining the oxidizing atmosphere, air, oxygen, carbon dioxide or the like can be used, and a gas having a resistance value higher than that of the non-oxidizing atmosphere is easily obtained, which is preferable. This is because a very dense and defect-free conductive layer is formed in a non-oxidizing atmosphere and a layer having high conductivity (low resistance) is obtained, but this is not the case in an oxidizing atmosphere. is there. Particularly, when the heat treatment is carried out in the air, it is very preferable in order to obtain a semiconductive inorganic substance having a medium resistance value in terms of treatment operation and economical efficiency. The heat treatment is 250 to 600 ° C.,
Desirably, it is performed at 300 to 450 ° C. If the heat treatment temperature is too lower than the above range, desired conductive performance cannot be obtained,
On the other hand, if it is too high, particle growth and sintering tend to occur, and hiding power and whiteness may be impaired. The heat treatment temperature time varies depending on the thickness of the coating layer, the type of heat treatment apparatus and the like and cannot be generally specified, but is usually 30 minutes to 5 hours, preferably about 1 to 2 hours. Further, by combining these conditions, it is possible to easily obtain a semiconductive inorganic material having various resistance values.

As another method, while stirring or flowing under an inert atmosphere or a reducing atmosphere,
100 ~ 6 by continuously introducing tin tetrachloride vapor and steam
There is a method of forming a conductive film on the surface of an inorganic material by reacting at 00 ° C (that is, by a CVD method).

In coating the surface of the inorganic material with conductive tin oxide, another inorganic material layer such as a layer of titanium oxide is formed on the surface of the inorganic material, and then a conductive layer is formed thereon. You may form. The amount of the titanium oxide layer is preferably 2 to 50% by weight based on the weight of the inorganic material. Since the crystal structure of the material of this coating layer and the crystal structure of the intermediate layer titanium oxide are the same, a tin oxide coating with excellent adhesion is formed, and as a result, not only excellent conductivity but also a conductive filler is added. When added to a resin or the like, the tin oxide coating that has been coated on the surface of the conductive filler does not peel off at the time of its mixing, resulting in loss of conductivity, and since a homogeneous intermediate layer exists, the inorganic material There is an effect that the conductivity does not decrease due to diffusion into the conductive layer. In addition, the presence of the titanium oxide intermediate layer having a high refractive index also imparts the effect of exhibiting excellent concealing properties in white.

The conductive material coating layer of the present invention is made of a tin oxide layer, a non-stoichiometric tin oxide layer, or a tin oxide doped with an element of Group 5 of the Periodic Table of Elements or a fluoride. And a layer made of tin-doped indium oxide. In the present invention, the non-stoichiometric tin oxide may be either oxygen or tin interstitial type or defect type.

When the conductive material layer is a layer made of tin oxide or a layer made of tin oxide having a non-stoichiometric composition, since a thin film of tin oxide alone is formed on the surface, it is preferable to use tin oxide doped with antimony. It is also inexpensive and has excellent whiteness because it does not generate a bluish black tone due to antimony dope, and the tin oxide thin film has transparency, and even if a semiconductive inorganic substance is mixed with a resin or the like. They do not impair their transparency, let alone coloring, and by adding other colorants, any desired color tone can be obtained, there is no problem of toxicity, and they are stable against temperature changes. It has a certain conductivity and a high dispersibility in plastics. For example, when the dispersion is performed using a paint shaker, it is possible to prepare a dispersion solution that is extremely unlikely to settle. Further, since this conductive layer is not composited by doping, it is very preferable because the resistance value shows a medium resistance region. When the layer of conductive material is a layer of tin oxide doped with an element of Group 5 of the Periodic Table of the Elements or a fluoride or a layer of tin-doped indium oxide, the element of Group 5 of the Periodic Table of Elements is preferably antimony. , An element selected from the group consisting of niobium or tantalum. Antimony dope is preferable because it is inexpensive and excellent in conductivity imparting property. Fluoride, niobium, tantalum-doped tin oxide and tin-doped indium oxide do not exhibit a bluish black tone like antimony dope,
It is preferable because it has excellent whiteness and there is no fear of toxicity unlike antimony. In the present invention, the dopant content is
It is 20% by weight, preferably 10% by weight, and more preferably 5% by weight or less, based on the conductive material. 20% by weight
When it exceeds, the color of the conductive filler is dark blue, the conductivity becomes high, and the resistance value becomes too low, which is not preferable. The thickness of the conductive layer of the present invention is 2 to 80 n.
m, preferably 10 to 30 nm. If the thickness of the coating is less than 2 nm, the conductivity of the coated inorganic material is insufficient, and therefore it is difficult to obtain a satisfactory antistatic effect even if such particles are mixed in the resin matrix. Moreover, even if the thickness of the coating exceeds 80 nm, the effect commensurate with the increasing cost cannot be achieved, resulting in high cost. When the coating is 10 to 30 nm, the binding force between the coating containing tin oxide as a main component and the particles of the inorganic material becomes relatively strong, and the coating does not peel off from the inorganic material even when kneaded into the resin. It has become.

The compounding ratio of these semiconductive inorganic materials is as follows. In the case of a granular semiconductive inorganic material, the compounding amount is 5 to 200 parts by weight with respect to 100 parts by weight of the polyimide resin. In the case of a needle-like or plate-like semiconductive inorganic substance, the compounding amount is 5 to 150 parts by weight, preferably 5 to 100 parts by weight, based on 100 parts by weight of the polyimide resin. 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, the film does not become black even if a colored conductive material such as carbon black or graphite is added. Further, in order to maintain transparency, the compounding amount is preferably 40 parts by weight or less. In addition, since the surface of the semiconductive inorganic material contains a large amount of tin oxide, it is excellent in dispersibility and has a strong bond with the polyimide, so that the tensile elongation is 35% and the tear propagation strength is 2%.
50g / mm or more, 50% of the product without filler
A polyimide resin composition having the above retention rate is easy to obtain. With a needle-shaped semi-conductive inorganic material, the tensile elongation is 60% or more, the tear propagation strength is 600 g / mm or more, and the tensile elongation is 80% compared to the filler-free product.
As described above, the tear propagation strength has a retention rate of 120% or more. Even if the semiconductive inorganic material is added, the water absorption rate can be maintained at 5% or less, and the increase rate of the water absorption rate can be suppressed to twice or less the original water absorption rate of the polyimide. When it is compounded with another conductive material, the addition amount of the semiconductive inorganic material is large, so that the dispersion of the other conductive material can be assisted 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. On the other hand, if the amount is larger than these amounts, mechanical properties are deteriorated and the material becomes brittle, which is not preferable.

By appropriately blending them, 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, and a material having excellent environmental stability can be adjusted. Also, the volume resistance value R _100V when _100V is applied and the volume resistance value R _1000V when 1000V is applied.
Can be the ratio of (R _100V / R _1000V) can be controlled within a range of 0.03 to 30, adjusting the voltage dependence of less material. Further, even if the number of added semiconductive inorganic materials changes by 5 in the range of the number of added parts, the change in volume resistance is 3 times or less, and a material having little dependence on the number of added parts can be prepared. Further, it is possible to suppress the variation in the resistance value between the samples to 3 times or less, and it is possible to adjust the material having the small variation between the samples.

Further, it was difficult to control the volume resistance value of the polyimide resin composition to a 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.

Further, the polyimide resin composition of the present invention whose volume resistance value is controlled by appropriately blending as shown in the examples has a volume resistance value within the range of 10 ⁹ to 10 ¹⁵ Ω · cm. Therefore, the retention of the total light transmittance can be 50% or more. Note that the total light transmittance retention here is
It refers to a value expressed as a percentage of the total light transmittance retention rate when the additive is introduced, based on the total light transmittance of the polyimide resin simple substance containing no additive such as a semiconductive inorganic material.

By adding a semi-conductive inorganic substance, it has a medium resistance value and high insulation property, the resistance value has little voltage dependency, and the resistance value and the insulation property do not fluctuate at high temperature and high humidity. The reason why a belt which is excellent in strength and dimensional stability and which is not black in color as required can be obtained is as follows. Also,
The compounding amount of semi-conductive inorganic material is much larger than the amount added for usual coloring, resistance control, and strength improvement, and the reason why mechanical properties and insulation properties do not deteriorate despite the addition of a large amount is as follows. This is the reason.

The semiconductive inorganic substance is 1 × 10 ³ to 1 × by itself.
It has a resistance of 10 ¹⁰ Ω · cm, carbon black, conductive metals and metal ceramics (1 × 10 ⁻⁵ to 1 × 10 ³ Ω).
・ Unlike cm, the resistance value is polyimide (1 × 10 ¹⁶
Ω · cm). Therefore, in the semiconductive inorganic material-added system, a sharp decrease in resistance due to percolation as seen in carbon black is not seen, and the resistance changes gently with respect to the added amount. 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 to which the semiconductive inorganic material 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 these facts, it can be said that the semiconductive inorganic material controlled to have a medium resistance is a material in which resistance changes little due to variations in the added amount.

It is considered that the semiconductive inorganic substance itself having a medium resistance plays a large 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 metal-based material as a conductive material and a medium resistance material such as a semiconductive inorganic material, the voltage applied to the polyimide is better when the medium resistance material is added. Considered small. 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 in which a medium resistance material such as a semi-conductive inorganic material is added, compared to the case where a low resistance material such as carbon black is added, it is possible to prevent a high voltage from being locally applied to the polyimide portion which is the resin. Therefore, the voltage dependence of the resistance value can be improved.

Since the semiconductive inorganic substance has a hydroxyl group and active oxygen on the surface, it undergoes a strong interaction 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 the material consisting of semiconductive inorganic material and polyimide, especially the reaction-curable linear polyimide is a strong composite material, such a skin layer is not formed, and a large change in resistance value and insulation property occurs. Absent.

In order to form a strong bond between the semiconductive inorganic material and the 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 the polyamic acid and the semiconductive inorganic material are mixed, there are mainly the following two methods. The first is to add a semiconductive inorganic material to the polyamic acid polymerization solvent in advance to prepare a semiconductive inorganic material dispersion solution, and then add a diamine and a dianhydride, which are raw materials for the polyamic acid, to polymerize the polyamic acid. There is a way to do it. As another method, there is a method of mixing a polyamic acid obtained by polymerization in advance and a semiconductive inorganic substance dispersion solution. Whichever such method is used, it is necessary to prepare a semiconductive inorganic substance dispersion solution. The specific gravity of the semiconducting inorganic material is larger than that of the resin, and it is very heavy, and when the semiconducting inorganic material is added to the solvent, it is immediately precipitated. As a result, when mixed with amic acid, a semiconductive inorganic substance aggregates are formed, and irregularities are formed on the surface, or a portion having locally different resistance is formed.

Therefore, it is advisable to add a dispersant to the semiconductive inorganic material 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,
One or a combination of two or more selected from the group consisting of Cs salt, Be salt, Mg salt, Ca salt, Sr salt, and Ba salt is preferable, and Li salt, Na salt, and K salt are preferable. Li
As the salt, a Li salt having a lattice energy of 1100 or less is preferable, and specifically, LiF, LiCl, LiBr, Li
I, LiSCN, LiCF ₃ SO _{3, and the} like. Among Na salts, Na salts having a lattice energy of 800 or less are preferable, and specifically, NaF, NaCl, NaB
r, NaI, NaSCN, NaCF ₃ SO _{3 and the} like. The K salt is preferably a K salt having a lattice energy of 800 or less, specifically, KF, KCl, KB.
r, KI, KSCN, KCF ₃ SO _{3 and the} like. These metal salts are preferable because the ions are easily dissociated at room temperature and the interaction with the semiconductive inorganic material 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 added in a predetermined amount of 1 part by weight or less with respect to 100 parts by weight of the polyimide resin,
Even 0.01 to 0.1 parts by weight or less is sufficiently effective. Generally, in the application of electric wire coating, when a metal salt is added, the insulating property deteriorates, and when it is added to a material having a dielectric constant of 4 or more, ionic conductivity increases, which is not particularly preferable, but polyimide and semiconductive inorganic materials are used. In the combination, since the polyimide is excellent in the insulating property and the dielectric constant is 4 or less, the insulating property and the voltage dependency of the resistance are not particularly deteriorated in the range of the above-mentioned composition.

A conductive substance may be added to the above polyimide resin in addition to the semiconductive inorganic substance. 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 to be blended with the above-mentioned 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. 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. Such an inorganic additive has a lower cohesive force than carbon black and is not black, and therefore has little adverse effect on cleaning.

As a mixing ratio of these, a predetermined amount of 20 parts by weight or less is preferably added to 100 parts by weight of the polyimide resin, preferably 5 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, it becomes difficult to exhibit the effect of using these conductive substances, so 0.01 part by weight or more,
It is preferable to add 0.1 part by weight or more, more preferably 1 part by weight or more, and further preferably 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.

Proper blending using these will result in a safe
Set 1 × 10⁶~ 1 x 10¹⁵Intermediate volume resistance of Ω · cm
A resistance value can be achieved. Also, resistance at normal temperature and humidity
Value R _nAnd high temperature and humidity volume resistance R_hRatio of (R_n/ R_h)But
It can be controlled within the range of 0.03-30 and has excellent environmental stability.
The material can be adjusted. When 100V is applied
Volume resistance R_100VAnd the volume resistance value R when 1000 V is applied
_1000VRatio of (R_100V/ R_{1 000V}) Is in the range of 0.03 to 30
Adjusting materials that can be controlled within and have less voltage dependence
You can In addition, within the range of the number of parts added, no semiconductivity
Even if the number of added parts of the machine changes by 5 parts, the fluctuation of the volume resistance is tripled.
Below, it is possible to adjust materials with little dependency on the number of added parts.
You can In addition, the variation in resistance between samples is 3
It can be reduced to less than double, and there is little variation between samples.
The material can be adjusted.

The polyimide having the above composition can be used in various shapes. However, it is particularly difficult for a thin one 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 semiconductive inorganic material or other conductive material to be added in the polyimide resin.

When the polyimide resin is soluble in a solvent, the powder or a powder prepared 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 in which the characteristic deterioration of the polyimide is not significantly caused. 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 for 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 and optionally using a reduced pressure 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. In addition, the addition of a catalyst is very preferable because it can reduce the heating time and suppress the thermal deterioration of the semiconductive inorganic material. In particular, the semiconductive inorganic material obtained by firing in an oxidizing atmosphere,
It is very important to shorten the heating time by adding a catalyst because the conductive film causes a change in conductivity due to heating for a long time. Moreover, since the heating time is short, it is possible to suppress the thermal deterioration of the resin and the deterioration due to the reaction between the resin and the semiconductive inorganic material, which is preferable. In addition, in the production method by adding a catalyst, the in-plane orientation of the resin proceeds, and the semiconductive inorganic material also tends to be oriented in a plane. As a result, in the case of a thin molded product having a thickness of 100 μm or less, the inorganic substances oriented in the thickness direction can be reduced, the electric insulation 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.
It is preferable because the humidity dependence of resistance can be reduced.

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 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-described embodiments.

[0082]

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

First, a method of preparing various semiconductive inorganic substances (fillers) will be described.

(Method for producing barium sulfate-tin oxide coated filler) Barium sulfate particles 10 having an average diameter of 0.1 μm.
0 g was dispersed in 1500 ml of water, the dispersion slurry was heated to 75 ° C., and a 25% aqueous sodium hydroxide solution was added dropwise to adjust the pH of the slurry to about 12. Then, an aqueous solution prepared by dissolving 46.5 g of sodium stannate hydrate (containing Na ₂ SnO ₃ : 76%) in 500 ml of water was added to the dispersion slurry, stirred for 30 minutes, and then a 20% aqueous sulfuric acid solution was added for 90 minutes. Neutralized to pH 2.5. The dispersion slurry was aged for 3 hours while maintaining the pH at 2.5 and 75 ° C., then filtered, washed and dried, and then dried in air at 450 ° C. for 2 hours.
Semi-conductive barium sulfate used in the examples after firing for a time
A tin oxide coated filler was obtained. This semi-conductive barium sulfate-tin oxide coated filler is 20 wt% tin as SnO _2.
Contained. 200 semiconductive barium sulfate filler
A test piece was formed by pressure molding at a pressure of 0 kg / cm ² , and the volume resistance value of the test piece was measured with a low resistance measuring instrument (manufactured by Mitsubishi Chemical Corporation,
It was measured using Loresta AP). Volume resistance value is 3.3
It was × 10 ⁵ Ω · cm.

When the firing conditions of the above filler were changed from air to nitrogen atmosphere, the volume resistance value was 1.0 ×.
It was 10 ² Ω · cm or less. In addition, the firing conditions can be adjusted to 1.0 by changing the mixing ratio of the air and the nitrogen atmosphere.
The resistance value could be controlled in the range of × 10 ^{2 to} 3.3 × 10 ⁵ Ω · cm.

(Barium Sulfate-Tin Oxide & Antimony Oxide
Preparation of coated filler) Sulfuric acid burr having an average diameter of 0.1 μm
100 g of um particles were dispersed in 1500 ml of water.
After heating the dispersed slurry to 75 ° C, sodium stannate
Hydrate (Na ₂SnO₃: 76% included) 41.16 g of water
Add an aqueous solution dissolved in 500 ml to the dispersion slurry
Then, after stirring for 30 minutes, a 20% sulfuric acid aqueous solution is added for 90 minutes.
Neutralized to pH 2.5. Then, the dispersion slurry
-Containing antimony chloride at pH 2.5 and 75 ℃
(SbCl₃2.11 g dissolved in dilute hydrochloric acid solution (containing 98%)
300 ml of the thawed aqueous solution and 25% caustic soda solution
Simultaneous parallel addition to the powdered slurry over 3 hours. End of addition
After that, keep the dispersed slurry at pH 2.5 and 75 ° C.
Aged for 3 hours, filtered, washed, dried and air
Sulfuric acid burr used in the examples after firing at 450 ° C. for 2 hours.
A um-tin oxide & antimony oxide coated filler was obtained. This
Semiconductive Barium Sulfate-Tin Oxide & Antimony Oxide Coating
Filler is antimony Sb₂O₃As 1.1% by weight,
SnO for tin₂The content was 17.0% by weight. volume
Resistance value is 1.3 × 10^FiveIt was Ω · cm.

When the antimony content of the above filler was changed from 1.1% by weight to 3.0% by weight as Sb ₂ O ₃ and the firing condition was changed from the air to the nitrogen atmosphere,
The volume resistance value was 1.0 × 10 ² Ω · cm or less.

(Method for producing aluminum borate-tin oxide coated filler, titanium oxide-tin oxide coated filler) Aluminum borate whiskers having a diameter of 1 μm and a length of 10 μm instead of barium sulfate particles, a diameter of 0.1 μm,
It was prepared in the same manner as the barium sulfate / tin oxide filler preparation method except that a titanium oxide whisker having a length of 1.6 μm was used. The volume resistance is 5.3 × 10 ⁷ Ω · cm,
It was 1.0 × 10 ⁸ Ω · cm.

(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 volume resistance value in the thickness direction of the film sample was measured as follows. 10 from a sample
Cut out 4 cm x 10 cm, temperature 23 ℃, humidity 55
% Rh environment (NN), temperature 30 ° C, humidity 80%
Rh environment (HH) left for 48 hours, and under the environment, Advantest digital ultra-high resistance / micro ammeter R83
40 and resiliency chamber R12702A were used to measure the volume resistance and surface resistance at 500V.

The tensile modulus and tensile elongation of the film sample were measured according to ASTM D882.

The tear propagation strength of the film sample was measured according to ASTM D1938.

The total light transmittance of the film sample was measured by a digital turbidimeter manufactured by Nippon Denshoku Industries Co., Ltd .: NDHH.
It was determined using a -20D model.

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, a liquid in which 2.78 g of barium sulfate-tin oxide coating filler was dispersed in 21 g of DMF was prepared.

These polyamic acid solutions and barium sulfate were used.
A tin oxide-coated filler dispersion was added and kneaded. Before casting the obtained dope into a tubular film, acetic anhydride / isoquinoline / DMF was added in an amount of 9.03 g / 11.4 g /
A solution consisting of 15.6 g was added and mixed, then cylindrical SU
Cast on S, 140 ℃ / 240sec, 275 ℃ / 40
Second heat treatment at 400 ° C./93 seconds to obtain a yellow polyimide tubular product of about 50 μm. The amount of filler in the present tubular product is 20 parts by weight with respect to 100 parts by weight of polyimide solid content.
The characteristic values are shown in Table 1. The linear expansion coefficient of the polyimide film thus polymerized is 21 ppm, the hygroscopic expansion coefficient is 16 ppm, the elastic modulus is 3 GPa, and the water absorption rate is 2.5.
%, The total light transmittance was 60%.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. When the volume resistance value was 1 × 10 ¹⁵ Ω · cm or less, the antistatic effect was improved. Also, the difference in the number of parts added with filler (5
The ratio of the volume resistance value by part) was 3 times or less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

The tensile modulus of the film was 3 GPa or more, the elongation was 70% or more, the tear propagation strength was 300 g / mm or more, and the mechanical properties were excellent. The tensile modulus of elasticity of the polyimide alone was 2.9 GPa, the elongation was 70%, and the tear propagation strength was 450 g / mm. Elongation is 100
%, And the propagation strength was maintained at 75% or more.

The total light transmittance was 32.0%, which was 60% of the polyimide alone.

Example 2 A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid prepared by dispersing 20.8 g of barium sulfate-tin oxide coating filler in 21 g of DMF was prepared. The amount of filler in the tubular product is 10% of polyimide solid content.
It is 150 parts to 0 parts by weight. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was adjusted to the desired medium resistance region. 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 less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

Tensile elastic modulus is 3 GPa or more, elongation is 70%
As described above, the tear propagation strength was 300 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 2.9 GPa, elongation 70%, tear propagation strength 450 g
/ Mm. Elongation is 100% or more,
The propagation strength was maintained at 75% or more.

Example 3 A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid having 21 g of DMF and 20.8 g of barium sulfate-tin oxide & antimony oxide coating filler dispersed therein was prepared. The amount of filler in the tubular product was 150 parts by weight with respect to 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was adjusted to the desired medium resistance region. 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 less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

The tensile elastic modulus is 2.5 GPa or more and the elongation is 3
It was 5% or more, the tear propagation strength was 250 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 2.9 GPa, elongation 70%, tear propagation strength 45
It was comparable to 0 g / mm. The elongation was 50% or more and the propagation strength was 55% or more.

Example 4 A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid prepared by dispersing 2.78 g of aluminum borate-tin oxide coating filler in 21 g of DMF was prepared. The amount of filler in the tubular product was 20 parts based on 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. When the volume resistance value was 1 × 10 ¹⁵ Ω · cm or less, the antistatic effect was improved. Also, the difference in the number of parts added with filler (5
The ratio of the volume resistance value by part) was 3 times or less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small.

The tensile elastic modulus is 4.0 GPa or more and the elongation is 7
The tensile strength was 0% or more, the tear propagation strength was 300 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 2.9 GPa, elongation 70%, tear propagation strength 45
It was comparable to 0 g / mm. The elongation was 100% or more and the propagation strength was 65% or more.

The total light transmittance was 33.0%, which was 60% of the polyimide alone. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the polyimide alone.

Example 5 A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid prepared by dispersing 8.34 g of aluminum borate-tin oxide coating filler in 21 g of DMF was prepared. The amount of filler in this tubular product was 60 parts based on 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was adjusted to the desired medium resistance region. 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 less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

Tensile elastic modulus is 5 GPa or more, elongation is 50%
As described above, the tear propagation strength was 600 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 2.9 GPa, elongation 70%, tear propagation strength 450 g
/ Mm. The elongation was 70% or more and the propagation strength was 130% or more. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the polyimide alone.

(Example 6) TMF 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 9.73 g of tin oxide-coated filler was dispersed was prepared. The amount of filler in this tubular product is 100% of polyimide solid content.
70 parts by weight. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was adjusted to the desired medium resistance region. 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 less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

Tensile elastic modulus is 5 GPa or more, elongation is 50%
As described above, the tear propagation strength was 600 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 2.9 GPa, elongation 70%, tear propagation strength 450 g
/ Mm. The elongation was 70% or more and the propagation strength was 130% or more. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the polyimide alone.

(Example 7) TMF was added to 21 g of DMF.
Tin oxide coated filler 9.73 g, carbon black (#
3030B: Mitsubishi Chemical Co., Ltd. A polyimide tubular product was obtained in the same manner as in Example 1, except that a liquid in which 0.55 g was dispersed was prepared. The amount of filler in this tubular product was 70 parts based on 100 parts by weight of polyimide solid content. Table 1 shows the characteristic values
Shown in.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was adjusted to the desired medium resistance region. 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 less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

Tensile elastic modulus is 5 GPa or more, elongation is 50%
As described above, the tear propagation strength was 600 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 2.9 GPa, elongation 70%, tear propagation strength 450 g
/ Mm. The elongation was 70% or more and the propagation strength was 130% or more. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the polyimide alone.

Example 8 A solution of polyamic acid in DMF 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 4, except that 5 equivalents of TMHQ and 5 equivalents of PMDA were further added to polymerize a polyamic acid DMF solution (solid content concentration 18.5%, solution viscosity 3,000 poise). A tubular product was obtained. The linear expansion coefficient of the polyimide film thus polymerized is 9 ppm, the hygroscopic expansion coefficient is 5 ppm, the elastic modulus is 6 GPa, the water absorption rate is 1.2%, and the total light transmittance is 6 ppm.
It was 0%.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was adjusted to the desired medium resistance region. 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 less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small. The variation within the same sample was three times or less, which was very small.

Tensile elastic modulus is 7 GPa or more, elongation is 50%
As described above, the tear propagation strength was 600 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 6
GPa, elongation 70%, tear propagation strength 450g / mm
Was comparable to. The elongation was 70% or more and the propagation strength was 130% or more. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the polyimide alone.

Example 9 A solution of polyamic acid in DMF 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 5, except that 5 equivalents of TMHQ and then 5 equivalents of PMDA were added to polymerize the polyamic acid in DMF solution (solid content concentration 18.5%, solution viscosity 3,000 poise). A tubular product was obtained.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value was 10 ¹⁵ Ω · cm or less, and the antistatic effect was improved. Also, the difference in the number of added fillers (5 parts)
The ratio of the volume resistance values was 3 times or less, and the dependency of the volume resistance value on the number of added parts was small. Moreover, the ratio of the volume resistance values of NN and HH was 30 times or less, and the environment dependency of the volume resistance value was small. Further, the ratio of the volume resistance values measured at 100 V and 1000 V was 30 times or less, and the voltage dependency of the volume resistance value was small. Further, as a result of measuring the volume resistance value at 500 V for five samples produced by the same operation as above, the difference between the maximum value and the minimum value was 3 times or less, and the variation between the samples was also very small.

The tensile elastic modulus is 6.5 GPa or more and the elongation is 7
The tensile strength was 0% or more, the tear propagation strength was 300 g / mm or more, and the mechanical properties were excellent. Tensile elastic modulus of polyimide alone 6 GPa, elongation 70%, tear propagation strength 450 g
/ Mm. Elongation is 100% or more,
The transmission strength was kept at 65% or more.

The total light transmittance was 36.0%, which was 60% of the polyimide alone. The linear expansion coefficient and the hygroscopic expansion coefficient were also several ppm lower than those of the polyimide alone.

(Comparative Example 1) Except that no dispersion was added,
A polyimide tubular product was obtained in the same manner as in Example 1. The amount of filler in the present tubular product is 0 part with respect to 100 parts by weight of the polyimide solid content. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. Volume resistance value is 1.0 x 10 ¹⁶Ω ・ cm and very
High and easy to be charged. Also, the ratio of the volume resistance values of NN and HH
Was 30 times or less.

(Comparative Example 2) A liquid in which 13.9 g of tin-doped indium oxide filler (Mitsui Mining & Smelting Co., Ltd .: Pastran ITO) was dispersed in 21 g of DMF was prepared.
A polyimide tubular product was obtained in the same manner as in Example 1. The amount of filler in this tubular product is 100 parts based on 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value of NN was adjusted to the target medium resistance region, but HH had a very low resistance value. 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. Further, the ratio of the volume resistance values of NN and HH was 1000 times or more, and the environment 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, as a result of measuring the volume resistance value at 500 V with respect to 5 samples prepared by the same operation as described above, the difference between the maximum value and the minimum value was 3 times or more, and the variation among the samples was very large. The variation within the same sample was three times or more, which was very large.

(Comparative Example 3) Titanium oxide was added to 21 g of DMF.
Tin oxide coated filler (Ishihara Sangyo Co., Ltd .: FT-300
0) A polyimide tubular product was obtained in the same manner as in Example 1 except that the liquid in which 8.34 g was dispersed was prepared. The amount of filler in this tubular product was 70 parts based on 100 parts by weight of polyimide solid content. The characteristic values are shown in Table 1.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value of NN was adjusted to the target medium resistance region, but HH had a very low resistance value. 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. Further, the ratio of the volume resistance values of NN and HH was 1000 times or more, and the environment 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, as a result of measuring the volume resistance value at 500 V with respect to 5 samples prepared by the same operation as described above, the difference between the maximum value and the minimum value was 3 times or more, and the variation among the samples was very large. The variation within the same sample was three times or more, which was very large.

(Comparative Example 4) TMF was added to 21 g of DMF.
Tin oxide coated filler 9.73 g, carbon black (#
3030B: A polyimide tubular product was obtained in the same manner as in Example 1 except that a liquid in which 4.17 g of Mitsubishi Chemical Corporation 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. Table 1 shows the characteristic values
Shown in.

Table 1 shows the measurement results of the volume resistance values of NN and HH.
Shown in. The volume resistance value of NN was adjusted to the target medium resistance region, but HH had a very low resistance value. 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. Further, the ratio of the volume resistance values of NN and HH was 1000 times or more, and the environment 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, as a result of measuring the volume resistance value at 500 V with respect to 5 samples prepared by the same operation as described above, the difference between the maximum value and the minimum value was 3 times or more, and the variation among the samples was very large. The variation within the same sample was three times or more, which was very large.

[0134]

[Table 1]

[0135]

EFFECTS OF THE INVENTION It has a stable medium resistance value from normal temperature and normal humidity to high temperature and high humidity, and has little change in resistance value between samples, addition amount change, voltage change, environmental change, and antistatic property by transport and electrophotography. A transparent or non-black polyimide resin that has excellent transferability and fixability on the machine, and is easy to clean the toner adhered by foreign matter inspection in FPC, TAB, etc., alignment over the film, and misprinting in transfer belt, fixing belt, etc. Can be obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/16 101 G03G 15/16 101 15/20 102 15/20 102 F term (reference) 2H033 BA11 BA25 BB01 BB18 BB28 2H071 BA42 DA09 DA12 2H200 HB13 HB45 HB46 HB47 JA01 JA25 JA27 JB06 JB45 JB46 JB47 JC03 JC15 JC16 JC17 MA02 MA17 MA20 MB01 MB02 MB04 MC15 4F071 A01 BF97 CM02 AE15AB02 AY21A24 AB30 AHAB21 AB24 AB30 AB16 AB27 AB02 AB16 AB02 AB16 AB02 AB16 AB02 AB21 AB24 AB26 AB16 AB27 AB02 DE106 DE136 DE146 DE186 DE236 DG046 DJ006 DJ016 DJ036 DJ046 DJ056 DK006 DL006 FD116 FD117 GM01

Claims (14)

[Claims] 1. A body is added to 100 parts by weight of a polyimide resin.
Product resistance is 1 × 10 ³~ 1 x 10^TenParticle size is 3 in Ω · cm
Containing 5 to 200 parts by weight of a semi-conductive inorganic substance having a size of μm or less,
Volume resistance value is 1 × 10⁶~ 1 x 10¹⁵Within Ω · cm
The polyimide resin composition according to claim 1. 2. The volume resistance value of the semiconductive inorganic material is 1 ×.
The polyimide resin composition according to claim 1, which has a particle diameter of 10 ⁴ to 1 × 10 ⁹ Ω · cm and 2 μm or less. 3. The semiconductor material according to claim 1, wherein the semiconductive inorganic material is an inorganic material coated with a conductive material.
The polyimide resin composition described in 1. 4. The inorganic substance is selected from the group consisting of barium sulfate, aluminum borate, mica, silica, glass, alumina, zinc oxide, titanium oxide, potassium titanate, wollastonite, calcium carbonate, talc and kaolin. The polyimide resin composition according to claim 3, which is at least one kind of inorganic substance. 5. The polyimide resin composition according to claim 3, wherein the inorganic substance is at least one inorganic substance selected from the group consisting of barium sulfate, aluminum borate and mica. 6. The conductive material is ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide), N.
TO (niobium-doped tin oxide), TTO (tantalum-doped tin oxide), FTO (fluoride-doped tin oxide) and T
It is at least 1 sort (s) of electroconductive substance selected from the group which consists of O (tin oxide), The polyimide resin composition in any one of Claims 3-5 characterized by the above-mentioned. 7. The conductive material is ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide),
At least one conductive material selected from the group consisting of NTO (niobium-doped tin oxide), TTO (tantalum-doped tin oxide), and FTO (fluoride-doped tin oxide), the doping content of which is the conductive material. Based on 10
It is below weight%, The polyimide resin composition in any one of Claims 3-5 characterized by the above-mentioned. 8. The polyimide resin composition according to claim 6, wherein the conductive substance is a conductive substance obtained by heat treatment in an oxidizing atmosphere. 9. The composition, in addition to the semiconductive inorganic material, is 0.01 to 2 with respect to 100 parts by weight of the polyimide resin.
The composition according to claim 1, further comprising 0 parts by weight of a conductive material.
The polyimide resin composition according to any one of to 8. 10. The volume resistance value of the composition is 1 × 10 ^6.
The polyimide resin composition according to claim 1, wherein the polyimide resin composition is in the range of 1 × 10 ¹³ Ω · cm. 11. The volume resistance value of the composition is 1 × 10 ⁹
It is in the range of 1 × 10 ¹⁵ Ω · cm, and the total light transmittance retention is 50% or more.
9. The polyimide resin composition according to any one of 9. 12. A polyimide film comprising the polyimide resin composition according to claim 1. 13. A polyimide tubular article made of the polyimide resin composition according to claim 1. 14. The polyimide tubular product according to claim 13, 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.