JP2002296919A - Polyimide endless belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide belt realizing price-reduction and low power consumption of an electrophotographic device with respect to the polyimide belt used for the electrophotographic device such as a laser beam printer or a facsimile equipment. SOLUTION: A tertiary amine compound is mixed into a polyimide precursor solution of which the characteristics of resin produced by molding and imidation are to be controlled by introducing inorganic fine particles such as a metallic filler or carbon black thereto. The polyimide belt with extremely high tear propagation strength is obtained by subsequent molding of the precursor solution into a belt shape, drying and imidation. Thereby a lift of a polyimide belt component is lengthened and, at the same time, thickness of the belt is made thin. On the whole, to provide the electrophotographic device with the polyimide belt installed therein at a low cost and to lower the power consumption are simultaneously attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrophotographic copying machine,
The present invention relates to a polyimide endless belt used for an electrophotographic device such as a laser beam printer, a facsimile, and a composite device thereof.

[0002]

2. Description of the Related Art In an electrophotographic apparatus, a uniform charge is formed on a photoreceptor made of a conductive material, an electrostatic latent image is formed by a laser beam or the like that modulates an image signal, and then the toner is charged with a charged toner. The latent image is developed into a toner image. Next, the toner image is transferred to a recording medium such as paper directly or via an intermediate transfer member to obtain a desired image.

Here, a method in which a toner image on a photosensitive member is primarily transferred to an intermediate transfer member, and then a secondary transfer of the toner image on the intermediate transfer member to a recording medium such as paper, that is, an image employing an intermediate transfer system The intermediate transfer belt used in the forming apparatus is, for example, polyvinylidene fluoride (JP-A-5-200904).
No.), polycarbonate (JP-A-6-228335)
No.), a blend of an ethylene-tetrafluoroethylene copolymer and a polycarbonate (JP-A-6-149083)
A conductive endless belt in which a conductive agent such as carbon black is dispersed in a thermoplastic resin such as No.

Further, in recent years, a method of fixing a toner image on a recording medium by heating the intermediate transfer member, that is, an intermediate transfer and fixing method has been disclosed in Japanese Patent Application Laid-Open No. 6-258960. In the intermediate transfer / fixing method, after a toner image is secondarily transferred to a recording medium via an intermediate transfer member, the intermediate transfer member is brought into contact with the intermediate transfer member by directly or indirectly heating the intermediate transfer member. This method fixes a toner image on a recording medium, and has the advantage that the size and cost of the device can be reduced as compared with a conventional device in which an intermediate transfer mechanism and a fixing mechanism are separated.

Here, the belt material used in the intermediate transfer and fixing systems is required to have mechanical strength to withstand the stress during driving and to withstand the heat of about 200 ° C. given during fixing. From this demand, a polyimide resin having both high mechanical strength and heat resistance is suitable for the material used for the intermediate transfer and the fixing belt.

The characteristics required for the belt material used in the intermediate transfer and fixing methods include a volume resistance value of 10 ⁶ to 1.
It has a so-called medium resistance of about 0 ¹⁰ Ω · cm. However, the volume resistivity of polyimide is 10 ¹⁵
It is as high as about 10 ¹⁸ Ω · cm, and it is essential to greatly reduce the resistance value of the resin. In order to achieve this object, a method of including a large amount of inorganic powder in a polyimide resin is generally used.

However, a large amount of inorganic powder present in the resin significantly lowers the toughness of the resin. As a result, cracks during driving of the existing polyimide intermediate transfer / fixing belt have been a problem. When such a belt is incorporated into an apparatus, a period until parts breakage such as cracks occur, that is, a part life is shortened. As a result, it is very problematic that belt replacement costs are incurred, which leads to an increase in the cost of the apparatus as a whole. Conventionally, in order to improve the toughness of the polyimide intermediate transfer and fixing belt, a method of increasing the thickness of the belt has been generally used.

However, this method has problems such as an increase in the cost of resin raw materials, and is one of the factors that hinder the cost reduction of electrophotographic apparatuses, which is the need of the times. Furthermore, when considering heat fixing via this belt, it is also required to increase the heat capacity of the heater for heating the belt as the belt thickness increases, and it is said that the power consumption as well as the cost of the heater having a high heat capacity increases. There are also problems.

[0009] Further, the surface of the molded product is treated with a coating having an ability to improve toughness. However, this method is also not preferable because it also causes problems such as an increase in the coating processing cost and the heat capacity and power consumption of the heater.

Therefore, as disclosed in JP-A-5-345369 and JP-A-10-198179, means for providing a reinforcing tape at the end of the belt for the purpose of preventing breakage has been proposed. However, this method is unsuitable in that the process of attaching the tape is very complicated and difficult, and the cost required for this process is increased.

[0011]

The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that a polyimide resin having extremely high toughness despite the fact that the resin contains an inorganic filler. The present inventors have found that the use of a belt material can provide an intermediate transfer and fixing belt in which all of the above problems have been solved, and have completed the present invention.

[0012]

In order to achieve the above-mentioned object, a polyimide endless belt of the present invention is an endless belt used for intermediate transfer and / or fixing of an electrophotographic apparatus, and is a polyamic endless belt. A polyimide molded article obtained by imidizing an acid tubular coating film in the presence of a tertiary amine compound is mainly used.

The tear propagation strength in at least one direction may be 3 × 10 ³ N / m or more.

Further, the polyimide molded body may contain an inorganic powder, and the content of the inorganic powder may be 5 to 60 parts by weight based on 100 parts by weight of the polyimide.

The polyimide endless belt according to the present invention has a volume resistivity of 10 ⁶ Ω · cm to ^{10 10} Ω ·
cm.

The thickness is 10 to 1000 μm, and the difference between the maximum thickness and the minimum thickness is 20% of the average thickness.
It can be:

The polyimide endless belt of the present invention may have a fluororesin composition layer on at least one surface.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an endless polyimide belt used in an electrophotographic apparatus such as an electrophotographic copying machine, a laser beam printer, a facsimile, and a composite machine thereof. Specifically, the transfer method of the endless polyimide belt of the present invention is an intermediate transfer belt method, and / or
Alternatively, the device to be incorporated is not particularly limited as long as it has a mechanism for directly or indirectly heating the belt. For example, a monocolor electrophotographic apparatus having only a single color (usually black) in the apparatus, a color electrophotographic apparatus in which a toner image carried on a photoreceptor is sequentially and primarily transferred to an intermediate transfer belt, and a developing apparatus for each color Any of a tandem-type color electrophotographic apparatus in which a plurality of latent image carriers provided with a device are arranged in series on an intermediate transfer belt may be used. Therefore, the polyimide endless belt of the present invention can be used not only for intermediate transfer and fixing, but also as an intermediate transfer belt and a fixing belt. The above-described intermediate transfer and fixing belt is a belt that performs an intermediate transfer process and a fixing process on the same belt.

The polyimide belt has an endless belt shape. The polyimide endless belt of the present invention is mainly composed of a polyimide molded body.

This polyimide molded article contains at least (A) a polyamic acid and (B) a tertiary amine in an organic solvent solution of a polyamic acid, which is a precursor of polyimide, and forms it into an endless belt. It is formed by imidization. The polyimide endless belt of the present invention preferably has a tear propagation strength in at least one direction of 3 × 10 ³ N / m or more. In addition, the volume resistivity is 10
It is preferably ⁶ to 10 ¹⁰ Ω · cm.

The polyamic acid as the component (A) is a precursor of polyimide, and is obtained, for example, by subjecting an aromatic tetracarboxylic acid component and a diamine component to a polymerization reaction in substantially equimolar amounts in an organic polar solvent.

The aromatic tetracarboxylic acid component that can be used in the production of the polyamic acid is not particularly limited. For example, butanetetracarboxylic dianhydride, 1,2,3,
4-cyclobutanetetracarboxylic dianhydride, 1,3-
Dimethyl-1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, 3,5 6-tricarboxynorbonane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofural) -3-methyl-3-cyclohexene -1,2-dicarboxylic dianhydride, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-
Aliphatic or alicyclic tetracarboxylic dianhydride such as tetracarboxylic dianhydride; pyromellitic dianhydride, 3,
3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenylethertetracarboxylic dianhydride, 3,3 ′,
4,4′-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfone dianhydride, 4,4′-bis ( 3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidene diphthalic dianhydride, 3,3 ′, 4,4′-
Biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p-phenylene-bis (triphenylphthalic acid) dianhydride, m-
Phenylene-bis (triphenylphthalic acid) dianhydride,
Bis (triphenylphthalic acid) -4,4'-diphenylether dianhydride, bis (triphenylphthalic acid)-
Aromatic tetracarboxylic dianhydride such as 4,4'-diphenylmethane dianhydride; 1,3,3a, 4,5,9b-hexahydro-2,5-dioxo-3-furanyl) -naphtho [1,2 -C] furan-1,3-dione, 1,3,3
a, 4,5,9b-Hexahydro-5-methyl-5-
(Tetrahydro-2,5-dioxo-3-furanyl)-
Naphtho [1,2-c] furan-1,3-dione, 1,
3,3a, 4,5,9b-hexahydro-8-methyl-
Examples thereof include aliphatic tetracarboxylic dianhydrides having an aromatic ring such as 5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione. it can. These tetracarboxylic dianhydrides can be used alone or in combination of two or more.

The diamine which can be used in the production of the polyamic acid is not particularly limited as long as it is a diamine.
Diaminodiphenylethane, 4,4′-diaminodiphenylether, 4,4′-diaminodiphenylsulfide, 4,4′-diaminodiphenylsulfone, 1,5
-Diaminonaphthalene, 3,3-dimethyl-4,4'-
Diaminobiphenyl, 5-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, 6-amino-1- (4′-aminophenyl) -1,3,3-trimethylindane, , 4'-Diaminobenzanilide, 3,5-diamino-3'-trifluoromethylbenzanilide, 3,5-diamino-4'-trifluoromethylbenzanilide, 3,4'-diaminodiphenylether, 2,7- Diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,
4'-methylene-bis (2-chloroaniline), 2,
2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-
5,5′-dimethoxybiphenyl, 3,3′-dimethoxy-4,4′-diaminobiphenyl, 4,4′-diamino-2,2′-bis (trifluoromethyl) biphenyl, 2,2-bis [4 -(4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-
Bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) -biphenyl, 1,3'-
Bis (4-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) fluorene, 4,4 ′-(p-
Phenyleneisopropylidene) bisaniline, 4,4 '
-(M-phenyleneisopropylidene) bisaniline,
2,2'-bis [4- (4-amino-2-trifluoromethylphenoxy) phenyl] hexafluoropropane, 4,4'-bis [4- (4-amino-2-trifluoromethyl) phenoxy]- Aromatic diamines such as octafluorobiphenyl; aromatic diamines having two amino groups bonded to an aromatic ring such as diaminotetraphenylthiophene and a hetero atom other than a nitrogen atom of the amino group; 1,1-metaxylylenediene Amine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,
4-diaminocyclohexane, isophoronediamine,
Tetrahydrodicyclopentadiene cyclopentadienylide diamine, hexahydro-4,7-meth Noin mite range diamine, tricyclo [6,2,1,0 ^2.7] - undecylenate range methyl diamine, 4,4'-methylenebis (cyclohexylamine) And the like, and aliphatic diamines and alicyclic diamines. These diamine compounds can be used alone or in combination of two or more. As the diamine, it is preferable to use an aromatic diamine, but it is not particularly limited.

Examples of the organic polar solvent used in the reaction for producing the polyamic acid include sulfoxide solvents such as dimethyl sulfoxide and diethyl sulfoxide.
Formamide solvents such as N, N-dimethylformamide and N, N-diethylformamide; acetamido solvents such as N, N-dimethylacetamide and N, N-diethylacetamide; N-methyl-2-pyrrolidone;
Pyrrolidone solvents such as vinyl-2-pyrrolidone, phenol, o-, m- or p-cresol, xylenol, halogenated phenols, phenol solvents such as catechol, ether solvents such as tetrahydrofuran, dioxane, dioxolan, methanol, ethanol,
Alcohol solvents such as butanol, cellosolves such as butyl cellosolve or hexamethylphosphoramide,
γ-butyrolactone and the like can be mentioned, and it is desirable to use these alone or as a mixture. Further, aromatic hydrocarbons such as xylene and toluene can also be used. The solvent is not particularly limited as long as it dissolves the polyamic acid.

The component (B) is not particularly limited as long as it is a tertiary amine compound. However, in order to effectively exhibit the effect of improving toughness in the present invention, imidazole, benzimidazole, isoquinoline, It is preferably a substituted or unsubstituted nitrogen-containing heterocyclic compound such as quinoline or a substituted pyridine such as β-picoline.

The tertiary amine compound is added in an amount of 5 to 2 tertiary amines per 100 g of the dry weight of the polyamic acid resin.
00 g, preferably 10 to 100 g, are added.

In the present invention, an inorganic powder can be further introduced into the polyimide resin layer of the endless polyimide belt in order to control its resistance and thermal conductivity. Here, when the inorganic powder causes a dispersion failure in the resin, a dielectric breakdown phenomenon of the material and an image failure occur. On the other hand, when the inorganic powder is very well dispersed in the resin, the number of contacts between the inorganic powders decreases, and as a result, the electrical conductivity and the thermal conductivity do not improve. In order to solve these conflicting problems, it is required that even if the inorganic powder is sufficiently dispersed in the resin, a sufficient contact point between the inorganic powders per unit volume can still be secured. To do so, the inorganic powder introduced into the resin should be 2
It is desirable that the average aspect ratio of at least one inorganic powder be 10 or more.

The type of the inorganic powder introduced into the resin is not particularly limited. For example, from the viewpoint of controlling the resistance value, a method of mixing an appropriate amount of conductive inorganic powder such as carbon black into a resin is most effective. In addition to carbon black, small-diameter metal particles, metal oxide particles, titanium oxide, various inorganic particles, and whiskers formed of a conductive material such as metal oxide can provide the same effect. . Further, an ionic conductive substance such as LiCl can be added.

From the viewpoint of controlling the thermal conductivity, examples thereof include aluminum nitride, boron nitride, alumina, silicon carbide, silicon, silica, and graphite. Among them, boron nitride is preferable because it has a high heat conduction function, exhibits a releasing effect, is chemically stable, and is harmless.

The amount of the inorganic powder contained in the belt is not particularly limited, but is based on 100 parts by weight of the polyimide.
It is desirable that the amount of the inorganic powder is in the range of 5 to 60 parts by weight. If it is less than this range, the purpose of controlling the resistance value and the thermal conductivity cannot be sufficiently exhibited. On the other hand, if it is more than this range, the toughness of the resin is reduced, which is not preferable.

If the difference between the maximum thickness and the minimum thickness of the polyimide endless belt is too large, it may cause wrinkles. The wrinkling of the belt induces a reduction in image quality when performing transfer and fixing, and therefore it is necessary to reduce it as much as possible. From this point, the difference between the maximum thickness and the minimum thickness of the polyimide endless belt is desirably 20% or less of the average thickness of the polyimide endless belt. In addition, "the thickness of the belt"
It is a thickness that can be measured with a thickness gauge that measures the distance between the belt and a flat plate that has an area of 5 mm ² or more, ignoring the height of protrusions with a width of 50 μm or less that specifically exist on the belt surface. is there.

The thickness of the endless belt made of polyimide is as follows:
If it is too thick, it is not preferable from the viewpoint of thermal conductivity and resistance value, and if it is too thin, its toughness is too small. Therefore, considering the use of the belt, it is desirable that the thickness of the belt is 10 to 1000 μm, preferably 30 to 150 μm.

[0033] The tear propagation strength is a value obtained by dividing the load required for tearing up and down a straight cut made in advance by the thickness of the belt, and is a parameter most notably indicating toughness. That is, a high tear propagation strength is consistent with a high toughness. Considering the application of the polyimide endless belt according to the present invention, since the belt is always subjected to a certain degree of tension during use, it is essential that the belt has toughness that does not break under this tension. From this point, it is preferable that the tear propagation strength in at least one direction of the endless belt made of polyimide is 3 × 10 ³ N / m or more. In particular, preferably 4 × 10 ³ N / m
It is desirable that this is the case. The greater the tear propagation strength, the more difficult the belt is to break. Therefore, from this viewpoint, there is no particularly preferable upper limit of the tear propagation strength, but if a realistic numerical value is given, 2 × 10 ⁴ N / m 2
It is as follows.

In the endless belt made of polyimide of the present invention, an embodiment in which a layer having other components is laminated on the outer layer may be selected. The outer layer is selected depending on the use and purpose, for example, a belt in which a film or the like made of a fluororesin composition made of polytetrafluoroethylene, polyvinylidene fluoride, or a mixture thereof, or the like is exemplified,
It is not limited to this.

Next, an example of a specific method of forming an endless belt made of polyimide will be described.

A polyamic acid solution, which is a precursor of a polyimide resin obtained by polymerizing an aromatic tetracarboxylic acid component and a diamine component in an organic solvent, is added with 5-200 g based on 100 g of the dry weight of the polyamic acid resin. Preferably 10 to 100 g of tertiary amine are mixed.

Next, this solution is made to contain a total of 5 to 60 parts by weight of two or more inorganic powders based on 100 parts by weight of the dry weight of the polyamic acid resin. As a method of incorporating the inorganic powder, a method of mixing the inorganic powder in an organic solvent and then polymerizing the monomer in the organic solvent, or a step in the course of the polymerization reaction or after completion of the reaction, and adding the inorganic powder to the solution. And a method of mixing a body or a dispersion thereof.

As a method for dispersing the inorganic powder and reducing the size of the aggregate, physical methods such as stirring with a mixer or a stirrer, parallel rolls, ultrasonic dispersion, and chemical methods such as introduction of a dispersant are used. Examples include, but are not limited to:

Next, this solution is applied to the inner or outer surface of a cylindrical mold. Instead of molds, molds made of various conventionally known materials, such as those made of resin, glass, and ceramic, can work well as the molds according to the present invention. Providing a glass coat, a ceramic coat, or the like on the surface of the mold, and using a silicone-based or fluorine-based release agent may be appropriately selected. Further, by moving the mold for controlling the film thickness, the clearance of which has been adjusted with respect to the cylindrical mold, through the cylindrical mold, the excess solution is eliminated and the thickness of the solution on the cylindrical mold is made uniform. If uniform thickness control of the solution is performed at the stage of applying the solution onto the cylindrical mold, it is not necessary to use a mold for controlling the film thickness.

Next, the cylindrical mold coated with the polyimide resin precursor solution is heated or placed in a vacuum environment to volatilize 30% or more, preferably 50% or more of the contained solvent. Further, this mold is heated at 200 ° C. to 450 ° C. to cause the imide conversion reaction to proceed. Thereafter, the resin is removed from the mold, and a desired polyimide endless belt can be obtained.

Although the method for producing a polyimide endless belt according to the present invention has been described above, the present invention is not limited to only these embodiments, and can be made by those skilled in the art without departing from the spirit thereof. Based on the knowledge, it can be implemented in a form in which various improvements, changes, and modifications are made.

[0042]

Next, embodiments of a polyimide endless belt and a method of manufacturing the same according to the present invention will be described in detail with reference to the following examples.

Example 1 1500 g of dimethylformamide (DMF) sufficiently dehydrated with a molecular sieve was placed in a vessel equipped with stirring blades, 200 g of 4,4′-diaminodiphenyl ether was added, and the mixture was stirred until it was completely dissolved. did. This system was cooled to about 0 ° C., and 218 g of pyromellitic dianhydride was gradually added, followed by thorough stirring. When the viscosity of the system became about 3000 poise, the stirring was stopped to obtain a polyamic acid solution. Next, metal filler TM
60 g of -200 (manufactured by Otsuka Chemical Co., Ltd .; filler on a flat plate having mica surface coated with conductive metal tin oxide / antimony, width 10 μm, thickness about 0.1 μm) and DMF30
0 g was placed in another container, stirred well, and further subjected to an ultrasonic disperser to uniformly disperse the metal filler in the dispersion. In another container, carbon black 30
15g of 30B (manufactured by Mitsubishi Chemical Corporation) and DMF300
g of the mixture, the mixture was stirred well, and the mixture was subjected to an ultrasonic disperser to obtain a particle diameter of about several μm. 98 g and 45 g of the metal filler dispersion and the carbon black dispersion obtained above were collected in the same beaker, respectively, and thoroughly stirred. In this beaker, 300 g of the polyamic acid solution obtained above
Was added and stirred well. Further, 15 g of isoquinoline was mixed into the solution. The amount of isoquinoline added was about 23 g based on 100 g of the dry weight of the polyamic acid resin. The content of the inorganic powder was about 28 parts by weight when the polyimide was 100 parts by weight.

The thus obtained polyamic acid
The isoquinoline-metal filler-carbon black mixed solution was poured into a cylindrical SUS mold having an inner diameter of 90 mm and a length of 450 mm to apply the solution to the entire inner surface of the cylindrical mold. The releasability after belt molding was improved by applying a fluorine-based release agent on the inner surface of the cylindrical mold in advance. Next, a 30 mmφ mandrel is inserted and fixed so that the center coincides with the cylindrical mold, and a SUS ring mold having an outer diameter of 89.5 mm, an inner diameter of 30 mmφ, and a liquid contact part angle of 30 ° is fixed to the mandrel. Was installed. Next, the ring-shaped mold is moved in parallel by injecting compressed air obtained by an air compressor into a cylindrical mold, and a 0.5 mm-thick polyimide resin precursor solution film is formed on the inner surface of the mold. Was molded. This mold coated with the polyimide resin precursor solution is placed in a vacuum dryer, and while rotating the mold so that the solution does not accumulate downward, 10 ⁻³ to
It was dried for 3 hours under conditions of rr and a temperature of 23 ° C. next,
Place the mold in the oven, from room temperature to 380 ° C, about 30
By raising the temperature over a period of minutes, the imide conversion reaction was allowed to proceed. Thereafter, the mold was allowed to cool at room temperature, the resin was removed from the mold, and the desired polyimide endless belt was obtained.

The thickness measurement, tear propagation strength measurement and volume resistance measurement of the polyimide endless belt obtained by the above-mentioned means were carried out as follows.

(Measurement of Belt Thickness) Ten test pieces were randomly cut from the obtained endless belt made of polyimide.
The measurement was performed using a film thickness gauge capable of measuring a minimum unit of 0.01 μm.

(Measurement of Tear Propagation Strength) Tear propagation strength was measured in accordance with JIS K7128 by cutting out a total of 10 test pieces from a plurality of endless belts made of polyimide prepared in the same manner. That is, a trouser tear test specimen of 150 mm × 50 mm was prepared, and the tear rate was 200 mm / mi.
n. The measurement was performed using an autograph S-100-C manufactured by Shimadzu Corporation equipped with a load cell capable of measuring a maximum of 1N.

(Volume Resistance) A test piece of 10 × 10 cm ² was cut out from the obtained endless belt made of polyimide, and its volume resistance was measured with an ultra-high resistance measuring device manufactured by Advantech.

As a result, the thickness of this polyimide endless belt was 70 ± 2 μm, and the tear propagation strength was (3.7).
± 0.3) × 10 ³ N / m, and the volume resistance value is 1 × 10 ⁸
Ω · cm.

[0050]

Example 2 A polyimide belt was prepared in the same manner as in Example 1 except that β-picoline was used instead of isoquinoline as the tertiary amine. The tear propagation strength of the obtained polyimide belt was (3.7 ± 0.3) × 10 ³ N
/ M. The volume resistivity of the obtained polyimide belt was 1 × 10 ⁸ Ω · cm.

[0051]

Example 3 A polyimide belt was prepared in the same manner as in Example 1 except that the weight of isoquinoline to be introduced was 10 g. The tear propagation strength of the obtained polyimide belt was (3.2 ± 0.2) × 10 ³ N / m. The volume resistivity of the obtained polyimide belt was 1 × 1
Was 0 ⁸ Ω · cm.

[0052]

Embodiment 4 Instead of TM-200, ET-300W
A polyimide belt was prepared in the same manner as in Example 1 except that (Otsuka Chemical Co., Ltd .; titanium oxide-based spherical filler, particle size: several μm) was used. The tear propagation strength of the obtained polyimide belt was (3.6 ± 0.2) × 10 ³ N / m.
Met. The volume resistivity of the obtained polyimide belt was 3 × 10 ⁸ Ω · cm.

Comparative Example 1 A polyimide endless belt was prepared in the same manner as in Example 1, except that isoquinoline was not contained. The thickness of the obtained endless belt made of polyimide is 69 ± 2 μm, the volume resistance value is 1 × 10 ⁸ Ω · cm, and the tear propagation strength is (1.5 ± 0.2) × 10 ³ N /. m.

It is apparent from the results of Examples 1 to 3 that the addition of the tertiary amine isoquinoline improved the toughness of the polyimide endless belt.

[0055]

As described above, the endless belt made of polyimide according to the present invention has an extremely high tear propagation strength as compared with the endless belt made of polyimide obtained by the conventional manufacturing method. Can be reduced. Therefore, the life of parts of the endless belt made of polyimide can be dramatically increased, and at the same time, the thickness of the belt can be reduced.In general, it is possible to provide an inexpensive electrophotographic apparatus incorporating the intermediate transfer / fixing belt, and to reduce power consumption. It is possible to reduce simultaneously.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/24 G03G 15/24 F term (Reference) 2H033 AA21 AA23 AA32 BA12 2H078 AA13 AA18 AA29 CC06 DD51 DD56 2H200 FA02 FA15 FA19 GB21 GB40 JA07 JA08 JC04 JC15 JC16 JC17 MA04 MA14 MA17 MA20 MB04 MC03 4J002 CM041 DA026 DA036 DA066 DE136 DF016 DJ006 DJ016 DK006 FD016 GM01 4J043 PA01 PA02 PA04 QB15 QB26 RA34 RA35 SA06 SB01 SB02 UA2 012 012 012 012 012 012 UA152 UA232 UA242 UA262 UA622 UA761 UA762 UB022 UB062 UB121 UB122 UB152 UB241 UB282 UB301 UB302 UB312 UB382 YA07 YA08 ZA31 ZA45 ZB51

Claims (8)

[Claims] 1. An endless belt used for intermediate transfer and / or fixing of an electrophotographic apparatus, wherein the polyimide is obtained by imidizing a tubular coating film of polyamic acid in the presence of a tertiary amine compound. Endless belt made of polyimide, mainly composed of a molded article. 2. The endless polyimide belt according to claim 1, wherein the tear propagation strength in at least one direction is 3 × 10 ³ N / m or more. 3. The endless polyimide belt according to claim 1, wherein the polyimide molded body contains an inorganic powder. 4. The content of the inorganic powder is 5 to 60 parts by weight based on 100 parts by weight of the polyimide.
The endless belt made of polyimide according to 1. 5. 10 ⁶ Ω · cm to ^{10 10} Ω · cm
The polyimide endless belt according to any one of claims 1 to 4, having a volume resistivity of: 6. The endless polyimide belt according to claim 1, which has a thickness of 10 to 1000 μm. 7. The endless polyimide belt according to claim 1, wherein a difference between the maximum thickness and the minimum thickness is 20% or less of the average thickness. 8. The polyimide endless belt according to claim 1, which has a fluorine-containing resin composition layer on at least one surface.