JP2002292657A - Method for manufacturing polyimide film composition, polyimide film composition, endless belt, fixing belt and opc photosensitive body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a polyimide film composition which enhances adhesion of a metal layer. SOLUTION: In the method for manufacturing the polyimide film composition, a polyimide precursor-containing liquid (A) is applied to the surface of a substrate and dried or semi-cured to form a precursor resin layer and a polyimide precursor-containing liquid (B) having a metal powder dispersed therein is applied to the precursor resin layer and cured under heating to form a polyimide resin layer and a metal dispersed polyimide resin layer, and the metal layer is formed on the metal dispersed polyimide resin layer. Alternatively, the polyimide precursor-containing liquid (A) is applied to the surface of the substrate to be cured under heating to form the polyimide resin layer and the polyimide precursor-containing liquid (B) having the metal powder dispersed therein is apaplied to the polyimide resin layer and cured under heating to form the metal dispersed polyimide resin layer and the metal layer is formed on the metal dispersed polyimide resin layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a polyimide coating composition, a polyimide coating composition, an endless belt,
It relates to a fixing belt and an OPC photoconductor. The endless belt can be used as a base material for an electromagnetic induction heating type fixing belt in an image forming apparatus such as an electrophotographic copying machine or a laser printer.

[0002]

2. Description of the Related Art As a method for heating a fixing member, for example, as described in Japanese Patent Application Laid-Open No. 2000-188177, in order to reduce the size, improve the performance, and save power of electrophotographic equipment, electromagnetic induction is used. Devices using the heat generation method have been newly developed. A metal tube can be used for the fixing member, but a belt member made of a deformable plastic film may be preferable in order to reduce the size of the device. In this case, a polyimide film having a thickness of 25 to 500 μm is used. A resin in which a metal layer is formed as a heating element on the surface of a resin is used.

When a belt is formed by forming a metal layer as a heating element on a plastic film, if there is a seam in the belt, a defect due to the seam occurs in an output image. Preferably, there is. Therefore, in order to form the metal layer, a seam is formed when a metal foil is attached, and it is necessary to perform plating so that a seam does not occur.

Conventionally, there are various techniques for applying metal plating to the surface of a plastic film, and a plastic film coated with metal has been used for various purposes.
For example, polyimide resin film with copper plating,
It is used as a flexible wiring board. However, it is known that this polyimide resin film has poor adhesion to plated metal. Therefore, various means for improving the adhesion have been proposed. For example, a method of etching a resin surface by a specific method (Japanese Patent Laid-Open No.
2070), a method of subjecting a resin surface to discharge plasma treatment (JP-A-5-251511), a method of subjecting a resin surface to hydrophilic treatment by a specific method (JP-A-5-90737), and a method of forming a metal layer on a resin surface. (JP-A-5-251844), a method using an adhesive for plating (JP-A-9-208911), and a method in which a surface of a polyimide precursor coating is treated with a coupling agent. Heat treatment method (JP-A-2000-204)
178 publication) and the like.

[0005] However, in the above processing method, even if a metal plating layer can be formed on the polyimide resin film,
For example, when used as a fixing belt, since it is repeatedly bent and heated and cooled repeatedly, there has been a problem that the adhesion is insufficient or gradually decreases. In addition, there is another problem that the manufacturing process becomes complicated and costs increase.

On the other hand, in the method of preparing a polyimide resin film, a solution of a polyimide resin precursor is generally applied onto a substrate, the solvent is dried, and if necessary, a semi-cured state is cured. In order to form the polyimide resin film into an endless belt shape, a columnar or cylindrical core is used as a substrate, and the polyimide resin film is cured and then removed.

[0007]

As described above, the present invention provides:
An object of the present invention is to provide a method for producing a polyimide coating composition capable of improving the adhesion of a metal layer, and a polyimide coating composition produced by the production method. Further, the present invention provides an endless belt having improved adhesion of a metal layer,
An object is to provide a fixing belt and an OPC photoconductor.

[0008]

Means for Solving the Problems To achieve the above object, the present inventors formed a metal-dispersed polyimide layer using a polyimide-containing liquid in which metal powder was dispersed, and formed a metal layer.
They have found that the adhesion of the metal layer can be greatly improved, and have reached the present invention. That is, the present invention
1> A polyimide precursor-containing liquid (B) in which a polyimide precursor-containing liquid (A) is applied to the surface of a substrate, dried or semi-cured to form a precursor resin layer, and a metal powder is dispersed on the precursor resin layer. ), And heat-curing to form a polyimide resin layer and a metal-dispersed polyimide resin layer, and forming a metal layer on the metal-dispersed polyimide resin layer.

<2> A polyimide precursor-containing liquid (B) in which a polyimide precursor-containing liquid (A) is applied to the surface of a substrate and cured by heating to form a polyimide resin layer, and metal powder is dispersed on the polyimide resin layer. ) Is applied and heat-cured to form a metal-dispersed polyimide resin layer, and a metal layer is formed on the metal-dispersed polyimide resin layer.

<3> The method according to claim 1, wherein the metal layer comprises an electroless plating layer formed by electroless plating and / or an electrolytic plating layer formed by electrolytic plating. It is a manufacturing method of the polyimide coating composition of said description.

<4> The method for producing a polyimide coating composition according to any one of <1> to <3>, wherein the substrate has a cylindrical or columnar shape.

<5> A polyimide coating composition produced by the method for producing a polyimide coating composition according to any one of <1> to <4>.

<6> An endless belt characterized in that the substrate is removed from the polyimide coating composition described in <5> to make it endless.

<7> A fixing belt characterized in that a substrate is removed from the polyimide coating composition described in <5> to make it endless, and a releasable functional film is formed on the surface thereof.

<8> The polyimide coating composition according to <5>, wherein the substrate is removed to be endless, and an undercoat layer, a charge carrier transfer layer, and a charge carrier generation layer are sequentially formed on the surface. OPC photoconductor.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A first method for producing a polyimide resin coating composition of the present invention comprises a polyimide precursor-containing liquid (A)
Is applied to the surface of the substrate, dried or semi-cured to form a precursor resin layer, and a polyimide precursor-containing liquid (B) in which metal powder is dispersed is applied on the precursor resin layer, and cured by heating. In this method, a resin layer and a metal-dispersed polyimide resin layer are formed, and a metal layer is formed on the metal-dispersed polyimide resin layer to produce a polyimide coating composition. Hereinafter, the first manufacturing method will be described with reference to FIG.

First, as shown in FIG. 1 (a), a polyimide precursor-containing liquid (hereinafter referred to as "polyimide precursor-containing liquid (A)") is applied to the surface of the substrate 1 to form a precursor resin layer 2. I do. As the material of the substrate 1, a metal such as aluminum or stainless steel, a fluororesin, a silicone resin, or a metal whose surface is coated with these resins can be used. When a metal is used, the surface may be plated with chromium or nickel in advance or a release agent may be applied so that the formed polyimide coating composition can be easily removed.

As the polyimide precursor used in the polyimide precursor-containing liquid, a polyamic acid obtained from a diamino compound and a tetracarboxylic dianhydride can be used. Examples of the solvent for dissolving the polyimide precursor include aprotic polar solvents such as N-methylpyrrolidone, N, N-dimethylacetamide, acetamide, and N, N-dimethylformamide.

The polyimide precursor solution used in the present invention can be obtained, for example, by reacting an aromatic tetracarboxylic dianhydride with an aromatic diamine component in an organic polar solvent. Representative examples of such aromatic tetracarboxylic acids include the following. For example, pyromellitic dianhydride, 3,3 ′, 4
4'-biphenyltetracarboxylic dianhydride, 3,
3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,3,4,4'-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1 2,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) ether dianhydride, or their tetracarboxylic esters, or mixtures of the above tetracarboxylic acids And the like.

On the other hand, the aromatic diamine component is not particularly limited, and may include paraphenylenediamine, metaphenylenediamine, 4,4'-diaminodiphenyl ether,
4,4′-diaminophenylmethane, benzidine, 3,
3'-dimethoxybenzidine, 4,4'-diaminodiphenylpropane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane and the like.

The method for applying the polyimide precursor-containing solution to the surface of the substrate is not particularly limited.
4131, a centrifugal molding coating method described in
No. 19437, JP-A-6-23
770, JP-A-3-1803
No. 09-85756 described in JP-A-9-85756.
Although a spiral coating method described in Japanese Patent Application Laid-Open No. H11-284131 can be mentioned, it is preferable to apply a dip coating method described in Japanese Patent Application No. 11-314011 described later.

The amount of the precursor-containing solution applied is preferably ²⁰⁰ to 1800 g / m ² in order to achieve the above-mentioned film thickness. If it is less than 200 g / cm ² , the film thickness may be insufficient, and if it exceeds 1800 g / m ² , the film thickness may be excessive.

The dip coating method is characterized by high productivity. However, in the ordinary method, the coating film thickness is governed by the viscosity of the coating liquid and the pulling speed. In addition, since the polyimide precursor solution has a problem that the viscosity is very high in spite of its low concentration, the wet film thickness of the film after application becomes too large, and it is difficult to apply the film to a desired film thickness. Therefore, it is preferable to apply a dip coating method described in Japanese Patent Application No. 11-314011 in which a float having a predetermined circular hole is floated in the coating solution and the substrate is pulled up through the circular hole.

The size (diameter) of the circular hole is appropriately adjusted depending on the desired film thickness. That is, the applied wet film thickness is
Regulated by the gap between the circular hole and the substrate, the dry film thickness is the product of the wet film thickness and the concentration of the coating solution. However, the gap is preferably 1 to 3 times the desired wet film thickness. The reason for making the ratio 1 to 3 times is that the dry film thickness is not always proportional to the wet film thickness due to the viscosity and / or surface tension of the coating solution and shrinkage during curing.

Hereinafter, the dip coating method described in Japanese Patent Application No. 11-314011 will be briefly described with reference to FIG.
In FIG. 2, the coating tank 12 is filled with a coating liquid 19 composed of a polyimide precursor solution, and a float 17 is floating on the upper part. Float 17 has a circular hole 18 at the top
Is provided.

At the time of coating, first, the circular hole 1 of the float 17 is
The base (core) 11 is immersed in the coating solution 19 through the substrate 8.
Next, when the substrate 11 is pulled up, the coating liquid 19
And the coating liquid 19 passing between the base 11 and the circular hole 18 exerts frictional resistance. At this time, float 17
Since it is floating, it can move with a slight force, and is always kept at a position where the frictional resistance is constant in the circumferential direction, that is, the gap with the base 11 is constant. Therefore, the base 1
Even if the gap with the substrate 1 is to be narrowed, the frictional resistance increases at that portion and the frictional resistance decreases on the opposite side, so that the float 17 moves so that the gap with the substrate 11 becomes constant, and the float 17 moves. Never contact. This function works even when the substrate 11 is bent or swayed or when the substrate 11 cannot be pulled up vertically due to unevenness in accuracy of the coating apparatus, and the float 17 moves following the direction in which the substrate 11 is pulled up. Therefore, the film thickness of the coating film 10 formed through the circular hole 18 becomes constant. Thus, the coating film thickness is not governed by the viscosity and the pulling speed, but is governed only by the gap.

After application, the solvent of the coating film 10 is dried,
Since the above-mentioned aprotic polar solvent used for the polyimide precursor has a low evaporation rate, the coating film may hang down during drying. In that case, the substrate 11 may be dried while the longitudinal direction of the substrate 11 is horizontal and the central axis is rotated. Further, the coating film 10 is immersed in a second solvent that is compatible with the aprotic polar solvent and does not dissolve the polyimide precursor, such as water or alcohol, and the aprotic polar solvent is dissolved in the second solvent. To accelerate the drying of the coating film 10. In order to obtain a desired film thickness, the solid content concentration (concentration of the polyimide precursor) of the coating solution 19 is 15 to 50% by mass, the viscosity is 0.2 to 100 Pa · s, and the pulling speed during coating is 0.2 to 100%. It is preferably 2 m / min.

After applying the polyimide precursor-containing solution, the solution is dried or semi-cured to form a precursor resin layer 2. Here, "drying" refers to heating at a temperature at which the solvent of the precursor-containing solution evaporates (a temperature at which the curing reaction by the dehydration-condensation reaction of the polyimide does not proceed), and specifically, the boiling point of the solvent used. It means to heat near. In practice,
Drying is carried out at about 50 to 150 ° C. (preferably 55 to 145 ° C.) for an appropriate time. Also, "semi-cured"
The term “cured state” refers to a cured state in which the curing reaction of the polyimide precursor does not completely proceed, and refers to a partially imidized state. Practically, about 200 ° C. (preferably 150 to
(250 ° C), setting the time appropriately will increase the strength slightly,
The precursor resin layer 2 is in a semi-cured state.

Next, a polyimide precursor-containing liquid in which metal powder is dispersed (hereinafter referred to as “polyimide precursor-containing liquid (B)”) is applied to the surface of the precursor resin layer 2, and FIG. As shown, the metal dispersed precursor resin layer 3 in which the metal powder is dispersed
To form

Examples of the metal (metal powder) dispersed in the polyimide precursor-containing liquid (B) include aluminum, copper, nickel, chromium, cobalt, gold, silver, tin and zinc, and a mixture thereof (alloy). ). The volume average particle size is preferably about 0.1 to 5 μm, and 0.2 to 5 μm.
2.0 μm is more preferred. The shape is spherical, scaly,
Needle-like, irregular shape, etc. may be used. In addition to the metal powder,
In order to increase the conductivity, a conductive powder such as carbon black or tin oxide having a smaller particle size than the metal powder used may be used in combination.

The mixing ratio of the metal powder to the polyimide precursor-containing liquid is 1 in terms of mass ratio (metal powder: polyimide precursor-containing liquid).
It is preferably about 0: 1 to 1: 1 and more preferably 5: 1 to 1: 1. The thickness of the metal-dispersed precursor resin layer 3 depends on the particle size of the metal powder, but is preferably about 0.5 to 5 μm.
8 to 3 μm is more preferable. It is preferable that a part of the metal powder is embedded in the metal dispersion precursor resin layer 3 and a part of the metal powder is exposed on the surface. For that purpose, the shape of the metal powder is preferably not spherical, and the higher the mixing ratio of the metal powder, the better.

As the polyimide precursor and the solvent, those similar to the polyimide precursor-containing liquid (A) can be used. However, even if they do not have the same composition as the polyimide precursor-containing liquid (A), Considering the dispersibility of the metal powder,
Different types may be used. The same method as the method for applying the polyimide precursor-containing liquid (A) can be applied to the method for applying the polyimide precursor-containing liquid (B).

Next, after drying and the like as necessary, a heat treatment is performed to completely advance the curing reaction of the polyimide.
As shown in (c), a polyimide resin layer 2 'and a metal-dispersed polyimide resin layer 3' are formed. By completely proceeding the curing reaction of the polyimide, the polyimide resin layer 2 ′
In addition, the metal-dispersed polyimide resin layer 3 'is integrated to form one resin layer, and the metal powder 4 exists in a highly dispersed state on the surface of the resin layer.

The heating temperature at which the curing reaction of the polyimide proceeds completely depends on the thickness of the layer and the processing time.
It is preferable that the temperature be about 350 to 450 ° C.
More preferably, it is 445 ° C.

By the above-mentioned heat treatment, a dehydration condensation reaction proceeds, and a polyimide resin is produced. By the above reaction, the precursor resin layer 2 and the metal-dispersed precursor resin layer 3 are integrated, and a resin layer in which the metal powder 4 exists in a highly dispersed state is formed on the surface. Since the metal powder 4 is embedded in the resin layer, high adhesion is ensured. When heating and curing the polyimide precursor,
When the dispersed metal is oxidized or altered, a method of heating in an inert gas such as nitrogen is preferably applied. Rather than providing a metal powder-dispersed polyimide resin layer to be described later after curing the polyimide precursor to form a polyimide resin layer, forming the metal-dispersed polyimide resin layer in a state before curing the polyimide precursor has higher adhesion. In many cases, it can be obtained.

Next, as shown in FIG. 1D, a metal layer 6 is formed on the surface of the metal-dispersed polyimide resin layer 3 '. When the metal layer is formed by electroless plating or the like, a catalytic metal deposition process is usually performed before the electroless plating.
The catalyst metal deposition process is divided into sensitizing and activating. Sensitizing is typically performed with stannous chloride and hydrochloric acid, and activating is typically performed with palladium chloride and hydrochloric acid. At this time, since the remaining tin ions inhibit the adhesion of the electroless plating layer, they are removed with an acid, or sensitizing and activating are treated as a one-liquid catalyst, and tin is removed with an accelerator solution. However, in the method for producing a polyimide resin composition of the present invention, since a polyimide resin layer in which metal powder is dispersed is formed, the above-described catalyst metal is not deposited, and an electroless plating layer or an electrolytic plating layer is directly formed. be able to.

To form the metal layer 6, first, an electroless plating layer is formed on the metal-dispersed polyimide resin layer 3 'by electroless plating, or an electrolytic plating layer is formed by electroplating. Is preferred. Further, an electrolytic plating layer may be formed by performing electrolytic plating on the electroless plating layer.

Metals to be electrolessly or electroplated include copper, nickel, chromium, cobalt, iron, gold, silver,
Examples thereof include tin and zinc, and a mixture (alloy) thereof may be used. The metal to be electrolessly plated and the metal to be electroplated may be the same or different.

Electroless plating is performed by reducing and depositing metal ions with a reducing agent such as formalin. When the metal is copper, the methods described in JP-A-4-72070 and JP-A-4-186891 can be applied. The thickness of the electroless plating layer formed by electroless plating is preferably 0.1 to 1 μm,
More preferably, it is 0.1 to 0.5 μm.

The electroless plating layer formed by the above-described electroless plating generally has a high resistance. Therefore, when it is necessary to supply an electric current to the metal layer 6, the electroless plating layer is formed on the electroless plating layer by the electrolytic plating. Is preferably formed.
In this case, the electroless plating layer functions as a catalyst and an electrode, and the electrolytic plating is performed by a general method to form the electrolytic plating layer. The purpose of the electroless plating in this case is to use the electroless plated layer as an electrode when the metal dispersed polyimide layer 3 'alone has insufficient resistance as an electrode during electrolytic plating.

The thickness of the electrolytic plating layer formed by electrolytic plating cannot be said unconditionally because it depends on the metal used and the application. For example, when a flexible wiring board is used,
5 to 50 μm when forming an electrolytic plating layer made of copper
It is preferable that When used as an electromagnetic induction heating element, the thickness is preferably 3 to 20 μm when forming an electrolytic plating layer made of copper, preferably 8 to 60 μm for nickel, and 10 to 60 μm for iron.
It is preferably 100 μm. In addition, flexible O
When used as a PC photoreceptor, the electrolytic plating layer is 0.5
It is preferably formed to a thickness of ５5 μm.

When electrolytic plating is performed directly on the metal-dispersed polyimide resin layer 3 ', a certain amount of current must flow through the metal-dispersed polyimide resin layer 3' so as to function as an electrode. Other conductive powders and the like may be dispersed to lower the resistance. Although the electrolytic plating layer is deposited on the metal powder exposed on the surface, part of the electrolytic plating layer is embedded in the metal-dispersed polyimide resin layer 3 ', so that the adhesion of the metal layer 6 composed of the electrolytic plating layer is ensured.

In the second method for producing the polyimide coating composition of the present invention, a polyimide precursor-containing liquid (A) is applied to the surface of a substrate and cured by heating to form a polyimide resin layer. A polyimide precursor-containing liquid (B) in which a powder is dispersed is applied and cured by heating to form a metal-dispersed polyimide resin layer, and a metal layer is formed on the metal-dispersed polyimide resin layer to produce a polyimide coating composition. Is the way.

That is, in the second production method, the polyimide precursor-containing liquid (A) is applied to the substrate surface and the polyimide precursor-containing liquid (B) in which metal powder is dispersed is applied. It is the same as the first production method except that each is cured by heating. By performing the two-stage heat curing in this manner, an effect is obtained that a metal-dispersed polyimide resin layer can be formed later on a polyimide resin layer that has been prepared in advance. If a polyimide film that has been heat-cured from the beginning (for example, an existing polyimide resin film) is used as the substrate, the heat-curing process is performed after applying the polyimide precursor-containing liquid (B) in which metal powder is dispersed. Just get better.

As described above, the polyimide coating composition produced by such a production method has a high adhesion of the metal layer, and thus is preferably used, for example, for an endless belt requiring adhesion of the metal layer. In order to obtain an endless belt from the polyimide coating composition, a cylindrical or cylindrical substrate is used as a substrate, and a polyimide coating composition is formed thereon by either the first or second production method, and the polyimide coating composition is used. By removing the substrate from the coating composition, an endless belt body, that is, an endless belt is obtained. The polyimide coating composition can be easily removed from the substrate by plating the surface of the substrate with chromium or nickel as described above or applying a release agent. In addition, when forming the electroless plating layer and the electrolytic plating layer, it is preferable to perform the rotation while rotating the substrate so that the film thickness does not become uneven. Further, it is preferable that the electrode at the time of electrolytic plating is cylindrical so as to surround the base.

The endless belt thus obtained can be used as a fixing belt or an OPC photosensitive member by a known method. Hereinafter, the fixing belt and the OPC photoconductor will be described.

In order to manufacture a fixing belt from the above-mentioned endless belt, it is preferable to form a functional coating having releasability on the surface of the endless belt in order to prevent toner from adhering.
Fluororubber As the functional coating, which according to Japanese Unexamined Patent Publication No. 9-22212 and JP 11-338283, fluorine resin particles and SiC optionally mixed with inorganic particles, for example, Al ₂ O ₃ Elastic release layer mainly composed of PTFE, and fluorine resin such as polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkylvinyl ether copolymer (PFA), and tetrafluoroethylene / hexafluoropropylene copolymer (FEP) Preferably, a layer is formed. The thickness of the formed functional film is preferably 2 to 35 μm, more preferably 10 to 30 μm. A known method can be applied to form the elastic release layer. In order to form the fluororesin layer, it is preferable to apply a method of dip coating and baking the aqueous dispersion.

Examples of the fluororubber include a copolymer of VdF containing vinylidene fluoride (VdF) as a main component and hexafluoropropylene (HFP) and a copolymer of VdF-HFP copolymer and tetrafluoroethylene (TFE). Fluorine-based elastomers such as an original copolymer and an alternating copolymer of TFE and propylene. In addition, a VdF-chlorotrifluoroethylene copolymer or a mixture of, for example, a silicone rubber, a fluorosilicone rubber, or the like and the above-mentioned fluorine-based elastomer containing VdF as a main component can be used. A fluororesin layer may be formed on the fluororubber layer.

Conductive particles may be dispersed in the fluororesin and / or fluororubber in order to improve durability and prevent toner from scattering. Examples of the conductive particles include carbon black, carbon beads obtained by granulating carbon black, carbon fiber, carbon-based substances such as graphite, metals or alloys such as copper, silver, and aluminum, tin oxide, indium oxide, and antimony oxide. SnO
Examples include conductive metal oxides such as _{2-In 2} O ₃ composite oxide, and conductive whiskers such as potassium titanate.

When the adhesion of the functional coating is insufficient,
A method such as roughening the surface of the endless belt or setting a higher temperature when baking the fluororesin may be employed. Further, a method of applying a coupling agent or a primer to the surface of the endless belt can also be applied. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent. Primers are polyphenylene sulfide,
It contains at least one compound selected from polyethersulfone, polysulfone, polyamideimide, polyimide and derivatives thereof, and a fluororesin. The thickness of the primer is preferably in the range of 0.5 to 10 μm.

In order to form a coupling agent, a primer layer, and a functional film on the endless belt, if necessary, the heat-curing before producing the resin coating composition before producing the endless belt. After the above layers are formed by coating or the like, heating and curing may be performed simultaneously with the calcination treatment of the fluororesin. The obtained fixing belt may be subjected to slit processing, punching processing, tape or rib winding processing, etc., as necessary.

OPC (organic photoco)
The substrate of the photoconductor is manufactured from the endless belt by, for example, a method described below. First,
A coating solution for the undercoat layer is prepared. The endless belt of the present invention is immersed in the prepared coating solution and dried at 50 to 150 ° C. for 5 to 20 minutes to form an undercoat layer. The thickness of the undercoat layer is
The thickness is preferably 0.1 to 5 μm.

Next, a coating liquid for forming a CGL (charge carrier generation layer) is prepared. The prepared coating solution is dip-coated on the undercoat layer, and dried at 20 to 150 ° C. for 5 to 20 minutes, and
GL is formed. It is preferable that the thickness of the CGL be 0.01 to 1 μm.

Subsequently, a coating liquid for forming a CTL (charge carrier moving layer) is prepared. The prepared coating solution is dip-coated on CGL and dried at 50 to 150 ° C. for 10 to 60 minutes to form CTL. It is preferable that the thickness of the CTL is 10 to 50 μm. By forming the above layers, OPC (organic photoconductor) is formed.
tor) A photoreceptor is manufactured.

[0055]

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

Example 1 N-methylpyrrolidone solution containing a polyimide precursor (trade name: U Varnish S, manufactured by Ube Industries, Ltd., solid content concentration: 18% by mass, viscosity: about 5 Pa ·
s) was used as a coating solution (polyimide precursor-containing solution (A)). Using an aluminum cylinder having an outer diameter of 84 mm and a length of 400 mm as a base, a silicone-based release agent (trade name: KS700, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to the surface thereof,
Baking treatment was performed at 30 ° C. for 30 minutes. On the other hand, as the float 17 shown in FIG. 2, a hollow annular body made of Teflon (registered trademark) resin having an outer diameter of 100 mm and a height of 30 mm was formed, and a circular hole having an inner diameter of 84.8 mm was formed from the upper part to the lower part.

As shown in FIG. 2, after the float 17 is floated on the coating solution 19 of the polyimide precursor-containing solution (A) in the coating tank 12, the substrate 11 is placed in the coating solution through the circular hole 18.
It was immersed at a speed of m / min and then pulled up at a speed of 1 m / min. The coating film 10 having a wet film thickness of about 350 μm was formed on the substrate 11, and the float 17 did not come into contact with the substrate 11 during the lifting. Then, the base 11
Was dried at 100 ° C. for 60 minutes while rotating at 15 rpm with its longitudinal direction horizontal, and further dried at 200 ° C. for 30 minutes.
The precursor resin layer was formed by heating for half an hour and semi-curing.
The film thickness in the semi-cured state was 50 μm.

Next, 5 parts (parts by mass, the same applies hereinafter) of irregular-shaped copper powder having a volume average particle diameter of 3 μm (trade name: Type E, manufactured by Japan Energy) were mixed with an N-methylpyrrolidone solution of a polyimide precursor (trade name). : U varnish A, manufactured by Ube Industries, solid content concentration 18% by mass, viscosity: about 5 Pa · s) 11
Was dispersed in a solution consisting of 4 parts of acetone and 4 parts of acetone by a ball mill to prepare a polyimide precursor-containing liquid (polyimide precursor-containing liquid (B)) in which metal was dispersed. Mass ratio (metal powder:
The polyimide precursor-containing liquid (B)) was 5: 2.

The prepared polyimide precursor-containing liquid (B) was used as a coating liquid, and the substrate was immersed and coated in the same manner as in the case of the polyimide precursor-containing liquid (A). However, the inside diameter of the circular hole of the float was 84.2 mm. As a result, a coating film made of a copper powder-dispersed polyimide precursor having a wet film thickness of about 40 μm was formed on the polyimide precursor coating. Thereafter, the substrate was dried at 120 ° C. for 30 minutes while rotating the substrate at 15 rpm while keeping its longitudinal direction horizontal, to form a metal dispersed precursor resin layer. The dry film thickness of the metal dispersion precursor resin layer is 5 μm.
m.

Next, while heating the furnace with a nitrogen gas, the mixture was heated at 350 ° C. for 30 minutes to be cured to form a polyimide resin layer and a metal-dispersed polyimide resin. As a result, a resin layer (polyimide resin layer and metal-dispersed polyimide resin) having a total thickness of 50 μm was formed. After cooling to room temperature, a thickness of 0.25μ
m of electroless copper plating, and then 2 μm-thick electrolytic copper plating to obtain a polyimide coating composition.

[0061] - composition and electroless plating conditions of the electroless plating bath _{- · CuSO 4 · 5H 2 O} : 10g / l, · EDTA · 2Na: 30g / l, · HCHO (37 wt%) solution: 5 g / l,・ PEG # 1000: 0.5 g / liter ・ Plating bath temperature: 65 ° C. ・ Agitating method: air stirring ・ Plating time: 8 minutes ・ Plating bath pH: 12.5

[0062] - composition and electroplating conditions for electroless plating bath _{- · CuSO 4 · 5H 2 O} : 120g / _{l, · H 2 SO 4: 150g} / liter, plating bath temperature: 25 ° C., & stirring method: air stirrer・ Plating time: 5 minutes,

The obtained polyimide coating composition was heated at 150 ° C.
Even when the metal layer was repeatedly bent while applying a constant force at the above temperature, the adhesion of the metal layer was strong and did not peel off.

(Example 2) Volume average particle diameter 5 μm as copper powder
m of spherical copper powder (trade name: Cu-HWQ5, manufactured by Fukuda Foil Powder Co., Ltd.) (hereinafter, “parts” means “parts by mass”) and carbon black (trade name: C9
A resin layer (a polyimide resin layer and a metal-dispersed polyimide resin) was formed in the same manner as in Example 1 except that 1 part of No. 75 (manufactured by Colombian Carbon) was added. Except that electroless copper plating was not performed, the thickness was 2 μm in the same manner as in Example 1.
m of electrolytic copper plating to obtain a polyimide coating composition. Even when the obtained polyimide coating composition was repeatedly bent at a temperature of 150 ° C. while applying a constant force, the adhesion of the metal layer was strong and did not peel off.

(Example 3) In Examples 1 and 2,
By extracting the polyimide coating composition from the substrate,
An endless belt made of the polyimide resin composition having an inner diameter of 84 mm was obtained.

From these endless belts, flexible OPC photosensitive members were produced in the following manner. First, 5 parts (mass parts, the same applies hereinafter) of 8 nylon (lactamide, manufactured by Dainippon Ink and Chemicals, Inc.) are dissolved in a mixed solvent of 40 parts of methanol and 60 parts of 1-butanol, and 3 parts of zinc oxide powder and Titanium powder (3 parts) was added and dispersed by a sand mill to prepare a coating solution. The endless belt was dip-coated on this coating solution and dried at 135 ° C. for 10 minutes to form an undercoat layer having a thickness of 5 μm.

Next, a polyvinyl butyral resin (BM-
1, 1 part of Sekisui Chemical Co., Ltd.) was dissolved in 19 parts of cyclohexanone, 3 parts of chlorogallium phthalocyanine was added, and the mixture was dispersed by a sand mill to prepare a dispersion. 20 parts of 2-butanone was further added to this dispersion, and this coating solution was dip-coated on the undercoat layer to form CGL having a thickness of 0.12 μm. Subsequently, 40 parts of N, N'-diphenyl-N, N '-(m-tolyl) benzidine as a charge transporting agent and a polycarbonate Z resin having a weight average molecular weight of 60,000 (Iupilon Z600, manufactured by Mitsubishi Gas Chemical Company) 60 Was dissolved in a mixed solvent consisting of 60 parts of monochlorobenzene and 150 parts of tetrahydrofuran. This coating solution is dip-coated on CGL,
After drying at 135 ° C. for 40 minutes, a CT having a thickness of 25 μm was obtained.
L was formed to prepare an OPC photoconductor.

The adhesion of the surface layer of each of the OPC photoreceptors thus prepared was examined by a goban peel test using Cellotape (registered trademark).
Since the adhesion of the metal layer was excellent, it was found that the adhesion of the entire surface layer was also excellent.

(Example 4) The same polyimide precursor-containing solution (A) as in Example 1 was used as a coating solution, and
A 9.8 mm, 400 mm long aluminum cylinder was used. As the float, a Teflon resin hollow annular body having an outer diameter of 50 mm and a height of 20 mm was prepared.
A polyimide imide coating composition was produced as described below using the one having a circular hole of mm.

First, after the float was floated on the coating solution, the substrate was immersed in the coating solution at a speed of 1.5 m / min and then pulled up at a speed of 1.5 m / min. Of about 600 μm was formed. Thereafter, the substrate was dried at 120 ° C. for 60 minutes while rotating the substrate at 20 rpm with its longitudinal direction horizontal, and further dried at 200 ° C.
For 30 minutes to obtain a semi-cured state. The film thickness in a semi-cured state was about 80 μm.

Next, the same polyimide precursor-containing solution (B) as in Example 1 was used as a coating solution, and dip coating was performed again. However, the inner diameter of the circular hole of the float was 30.06 mm. As a result, a copper powder-dispersed precursor resin layer having a wet film thickness of about 40 μm was formed on the polyimide precursor film. Then, while rotating the base at 15 rpm with its longitudinal direction horizontal, 1
After drying at 20 ° C. for 30 minutes, the dry film thickness was 5 μm.
m.

Next, the polyimide precursor was cured by heating at 350 ° C. for 30 minutes while filling the heating furnace with nitrogen gas. As a result, a resin layer (polyimide resin layer and metal-dispersed polyimide resin layer) having a total thickness of 80 μm was formed. Then, after forming an electroless plating layer of 0.1 μm in thickness by electroless copper plating, an electroplating layer of 5 μm in thickness is formed on the electroless plating layer in the same manner as in Example 1. Thus, a polyimide coating composition was obtained.
The conditions for the electroless copper plating are as follows.

[0073; - composition of the plating bath _{- · CuSO 4 · 5H 2 O} : 10g / l, · EDTA · 2Na: 30g / l, · HCHO (37 wt%) solution: 5 g / l, · PEG # 1000: 0. 5 g / liter-Plating conditions-Plating bath temperature: 65 ° C., Stirring method: Air stirring, Plating time: 2.5 minutes, Plating bath pH: 12

When the substrate was removed from the polyimide coating composition and the obtained endless belt was repeatedly bent at a temperature of 150 ° C., the adhesion of the copper layer was strong.

(Example 5) In Example 4, a silicone primer (trade name: Chemloc 607, manufactured by Lord Far East, Inc.) was dip-coated on the surface of the polyimide coating composition which had not been peeled off from the substrate. Then, a primer layer having a thickness of 1 μm was formed.

On the other hand, VdF-HFP containing magnesium oxide and calcium hydroxide as vulcanizing components and metal oxides
-TFE tertiary polyol vulcanized fluororubber (trade name: G-621, manufactured by Daikin Industries, Ltd.) is dissolved in a mixed solvent of MIBK + MEK at a weight ratio of 8: 2, and a 10% concentration of fluorocarbon is dissolved. A raw rubber solution was prepared and used as a coating solution. This was dip-coated on the primer layer, heated at 100 ° C. for 30 minutes to dry the solvent, and further vulcanized at 220 ° C. for 3 hours to form a 10 μm-thick fluororubber elastic layer.

Further, an aqueous dispersion of PFA (trade name: AD
2CR, manufactured by Daikin Industries, Ltd.)
The coating was dried at 0 ° C. for 10 minutes, and further subjected to a heat treatment at 350 ° C. for 1 hour to form a fluororesin release layer having a thickness of 10 μm. The fixing belt obtained by removing the substrate could be used as a fixing belt of an electromagnetic induction heating type. Also, no peeling of the surface layer was observed during use.

(Example 6) In the same manner as in Example 1, a polyimide precursor was applied on a substrate, semi-cured, and then cured.
It was cured by heating at 0 ° C. for 30 minutes. After cooling to room temperature, the polyimide resin film was removed from the substrate. The film thickness is
It was 45 μm. At this stage, the polyimide resin film could be used as a transport belt.

Next, the polyimide resin film was again covered on the substrate. A polyimide precursor-containing liquid in which copper powder was dispersed was applied thereon in the same manner as in Example 1, and after drying the solvent, the mixture was heated at 350 ° C. for 30 minutes while filling a heating furnace with nitrogen gas, thereby obtaining a polyimide precursor. The body was cured. As a result, a polyimide resin film having a total thickness of 50 μm was formed. After cooling to room temperature, a surface of 0.25 μm was applied in the same manner as in Example 1.
After applying an m-thick electroless copper plating, a 2 μm-thick electrolytic copper plating was applied.

The obtained polyimide resin film had strong adhesion to the metal layer even when the film was repeatedly bent at a temperature of 150 ° C., and did not peel off. According to the method as in the sixth embodiment, a metal layer having strong adhesion can be provided even for a belt that has not been used as a transport belt (surplus).

(Comparative Example 1) In Example 1, after applying the polyimide precursor film, it was dried as it was (120 ° C, 60 ° C).
Min) and heat curing (350 ° C., 20 min) to form a polyimide coating composition. Then, Japanese Patent Laid-Open No.
As described in Examples of JP-A-91, the catalyst was applied by treating with a catalyst and an accelerator.
Next, electroless copper plating (thickness: 0.25 μm) is performed,
Further, electrolytic copper plating (thickness: 2 μm) was performed. When this copper layer (metal layer) was repeatedly bent at room temperature, a part of the metal layer peeled off little by little, and the adhesion of the metal layer was not good.

Comparative Example 2 In Comparative Example 1, before the polyimide coating composition was treated with a catalyst and an accelerator, a hydrophilic treatment was performed with concentrated sulfuric acid. Otherwise in the same manner as in Comparative Example 1, a polyimide coating composition with a copper layer was produced.
This copper layer (metal layer) had good adhesion at a temperature of 150 ° C., but when it was repeatedly bent, part of the metal layer peeled off little by little, and the adhesion of the metal layer was not good.

[0083]

According to the method for producing a polyimide coating composition of the present invention, it is possible to produce a polyimide coating composition in which the adhesion of the metal layer is improved. When a belt, a fixing belt, and an OPC photoconductor are manufactured, an endless belt and a fixing belt having improved adhesion of a metal layer can be obtained.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view showing an outline of a production process of a polyimide coating composition of the present invention, wherein (a) shows a state where a precursor resin layer is formed, and (b) further shows a state where a metal-dispersed precursor resin layer is formed. (C) shows a state after heat treatment, and (d) shows a state in which a metal layer is further formed.

FIG. 2 is an explanatory view schematically showing a step of applying a polyimide precursor solution.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... Precursor resin layer 2 '... Polyimide resin layer 3 ... Metal dispersion precursor resin layer 3' ... Metal dispersion polyimide resin layer 4 ... Metal powder 6 ...・ Metal layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G03G 21/00 350 G03G 21/00 350 // B29K 79:00 B29K 79:00 103: 06 103: 06 B29L 29:00 B29L 29:00 F-term (Reference) 2H033 BA11 BA12 BE06 2H035 CA05 CB06 2H068 AA21 AA52 AA55 BB50 BB58 EA07 4F202 AA40 AD03 AD08 AG16 CA04 CA07 CB01 CB26 CM46 CN01 CN05 4F205 AA40 AD03 AD08 AG16 GE02 GF02 GB02 GE02 GB02 GN21 GW06 GW23

Claims (8)

[Claims] 1. A polyimide precursor-containing solution in which a polyimide precursor-containing liquid (A) is applied to the surface of a substrate, dried or semi-cured to form a precursor resin layer, and a metal powder is dispersed on the precursor resin layer. A method for producing a polyimide coating composition, comprising applying a liquid (B), heating and curing to form a polyimide resin layer and a metal-dispersed polyimide resin layer, and forming a metal layer on the metal-dispersed polyimide resin layer. . 2. A polyimide precursor-containing liquid (A) is applied to the surface of a substrate and cured by heating to form a polyimide resin layer.
Applying a polyimide precursor-containing liquid (B) in which a metal powder is dispersed on the polyimide resin layer and curing by heating to form a metal-dispersed polyimide resin layer, and forming a metal layer on the metal-dispersed polyimide resin layer. A method for producing a polyimide coating composition. 3. The metal layer according to claim 1, wherein the metal layer comprises an electroless plating layer formed by electroless plating and / or an electrolytic plating layer formed by electrolytic plating. A method for producing a polyimide coating composition according to the above. 4. The method for producing a polyimide coating composition according to claim 1, wherein the substrate has a cylindrical shape or a columnar shape. 5. A polyimide coating composition produced by the method for producing a polyimide coating composition according to claim 1. Description: 6. An endless belt, wherein the substrate is removed from the polyimide coating composition according to claim 5 to make it endless. 7. A fixing belt comprising a substrate removed from the polyimide coating composition according to claim 5 to have an endless shape, and a releasable functional film formed on the surface thereof. 8. A base material is removed from the polyimide coating composition according to claim 5 so as to be endless, and a subbing layer is provided on the surface thereof.
An OPC photoconductor comprising a charge carrier transfer layer and a charge carrier generation layer formed sequentially.