JP2019200318A - Belt, endless belt, intermediate transfer belt and image formation device - Google Patents

Abstract

To provide a belt excellent in flex durability.SOLUTION: The belt comprises an imide resin layer containing native imide resin (A), siloxane modified imide resin (B) and conductive agent treated with siloxane (C).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a belt, an endless belt, an intermediate transfer belt, and an image forming apparatus.

  In an image forming apparatus using an electrophotographic method (copier, facsimile, printer, etc.), a toner image formed on the surface of an image carrier is transferred to the surface of a recording medium and fixed on the recording medium to form an image. Is done. In a transfer device that transfers such a toner image to a recording medium, a tubular belt is used as a belt member or the like. In forming such a belt, a resin composition containing a resin such as an imide resin is used.

  For example, Patent Document 1 states that “an endless tubular belt containing a siloxane-modified polyimide resin or a siloxane-modified polyamideimide resin, the surface side of the endless tubular belt has a polyimide property, and the back side has a silicone property. In addition, an endless tubular belt is disclosed, which is an inclined material whose physical properties continuously change in the thickness direction from the front surface side to the back surface side thereof.

  Patent Document 2 states that “contains 3 to 80 parts by weight of a conductive filler with respect to 100 parts by weight of a polyether aromatic imide resin, and has a volume resistivity of 1 × 10 4 Ω · cm or more and 1 × 10 13 Ω · A polyether aromatic imide resin composition characterized by having an antistatic performance of less than 1 cm "is disclosed.

  Patent Document 3 states that “a semiconductive polyimide belt containing a silicon-modified polyimide having a molar content of silicon-containing repeating units of 0.1 / 100 to 15/100, and the belt has a tensile elastic modulus of 2000 MPa or more. A semiconductive polyimide belt having a friction coefficient of the belt outer surface of less than 0.4 and a ratio of the friction coefficient of the belt inner surface to the outer surface (ratio of inner surface / outer surface) of 1.1 or more is disclosed.

JP 2007-072197 A JP 2004-182833 A JP 2008-197365 A

  The problem of the present invention is that the belt having an imide resin layer containing a non-modified imide resin, a siloxane-modified imide resin, and a conductive agent has improved bending durability compared to the case where the conductive agent is an untreated conductive agent. It is to provide an excellent belt.

  The above problem is solved by the following means.

<1>
A belt having an imide resin layer containing an unmodified imide resin (A), a siloxane-modified imide resin (B), and a siloxane-treated conductive agent (C).
<2>
The belt <3> according to <1>, wherein the siloxane-treated conductive agent (C) is siloxane-treated carbon black.
The belt according to <1> or <2>, wherein the siloxane treatment of the siloxane-treated conductive agent (C) is a dimethylsiloxane treatment.
<4>
The belt according to any one of <1> to <3>, wherein the siloxane-modified imide resin (B) is a dimethylsiloxane-modified imide resin.
<5>
The content of the siloxane-modified imide resin (B) with respect to 100 parts by mass of the unmodified imide resin (A) is 5 parts by mass or more and 50 parts by mass or less, according to any one of <1> to <4>. Belt.
<6>
The belt according to <5>, wherein the content of the siloxane-modified imide resin (B) is 10 parts by mass or more and 40 parts by mass or less.
<7>
<1> to <4>, wherein the content of the siloxane-treated conductive agent (C) with respect to 100 parts by mass of the unmodified imide resin (A) is 10 parts by mass or more and 40 parts by mass. Belt.
<8>
The belt according to <7>, wherein the content of the siloxane-treated conductive agent (C) is 15 parts by mass or more and 30 parts by mass or less.
<9>
The belt according to any one of <5> to <8>, wherein a mass ratio of the siloxane-treated conductive agent (C) to the siloxane-modified imide resin (B) is 0.2 or more and 8.0 or less. .
<10>
An endless belt comprising the belt according to any one of <1> to <9>.
<11>
An intermediate transfer belt comprising the endless belt according to <10>.
<12>
An image forming apparatus comprising the endless belt according to <10>.

According to the invention according to <1> to <4>,
A belt having an imide-based resin layer containing an unmodified imide-based resin, a siloxane-modified imide-based resin, and a conductive agent provides a belt that is superior in bending durability as compared with the case where the conductive agent is an untreated conductive agent. .

According to the inventions according to <5> and <6>,
Compared to the case where the content of the siloxane-modified imide resin (B) with respect to 100 parts by mass of the unmodified imide resin (A) is less than 5 parts by mass or more than 50 parts by mass, a belt having excellent bending durability is provided.

According to the inventions according to <7> and <8>
Provided a belt with excellent bending durability compared to the case where the content of the conductive agent (C) treated with siloxane with respect to 100 parts by mass of the unmodified imide resin (A) is less than 10 parts by mass or more than 40 parts by mass Is done.
According to the invention according to <9>,

  As compared with the case where the mass ratio of the siloxane-treated conductive agent (C) to the siloxane-modified imide resin (B) is less than 0.2 or more than 8.0, a belt having excellent bending durability is provided.

According to the invention according to <10> to <12>,
Endless belt with superior bending durability compared to the case where a belt having an imide resin layer containing an unmodified imide resin, a siloxane-modified imide resin, and a conductive agent is used where the conductive agent is an untreated conductive agent. There are provided a belt, an endless intermediate transfer belt, and an image forming apparatus including the endless belt.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

  Embodiments that are examples of the present invention will be described below. In the following description, reference numerals may be omitted.

  The belt of this embodiment has an imide resin layer containing an unmodified imide resin (A), a siloxane modified imide resin (B), and a siloxane-treated conductive agent (C). .

  The belt of this embodiment has the above-described configuration, whereby a belt having excellent bending durability can be obtained. The reason is not clear, but is presumed as follows.

Conventionally, when applying a belt having an imide resin layer having excellent dimensional stability to a belt such as an intermediate transfer belt, it has been necessary to add a conductive agent such as carbon black in order to obtain a necessary electric resistance. . However, if the conductive agent is untreated, the adhesive strength at the interface between the conductive agent and the amorphous thermoplastic resin tends to be insufficient, and the belt may be cracked. When cracks occur in the belt, when repeatedly used, the strength against repeated deformation stress is not sufficient and the bending durability may be inferior.
Furthermore, the conductive agent is blended in the resin layer of the belt, so that the elongation of the belt is restrained against deformation stress, the belt is always subjected to a high load, and can be used for a long time from the viewpoint of durability. It was difficult.
In contrast, the belt of this embodiment has an imide resin layer containing an unmodified imide resin (A), a siloxane modified imide resin (B), and a siloxane-treated conductive agent (C). doing.
The siloxane-modified imide resin (B) contained in this imide resin layer has an imide group and a siloxane bonding group. The unmodified imide resin (A) contained in the imide resin layer has an imide group, and the siloxane-treated conductive agent (C) has a siloxane bonding group.
Therefore, the siloxane-modified imide resin (B) has a high affinity with the unmodified imide resin (A) due to the affinity between those having an imide group, and also has a siloxane bonding group. The affinity with the conductive agent (C) is also high due to the affinity.
Therefore, the unmodified imide resin (A), the siloxane modified imide resin (B), and the siloxane-treated conductive agent (C) contained in the imide resin layer of the belt according to the present embodiment are mixed well with each other. The siloxane-treated conductive agent (C) has high adhesive strength at the interface with the siloxane-modified imide resin (B) due to the above-mentioned affinity, and has high dispersibility in the imide resin layer. it is conceivable that.
Furthermore, both the siloxane-modified imide resin (B) and the siloxane-treated conductive agent (C) have a siloxane group, and the siloxane group is a functional group having a high degree of rotational freedom in terms of molecular structure. The belt of the present embodiment is considered to exhibit followability with respect to repeated deformation stress and to exhibit durability during long-term use.
From the above, in this embodiment, it is estimated that a belt having excellent bending durability can be obtained.

The belt according to this embodiment has an imide resin layer containing an unmodified imide resin (A), a siloxane modified imide resin (B), and a siloxane-treated conductive agent (C).
With the above configuration, the belt according to this embodiment is excellent in bending durability, resistance stability, and dimensional stability. Further, when the belt according to the present embodiment is used as, for example, an electrophotographic belt, toner adhesion is reduced, so that defective cleaning is suppressed.
The belt according to the present embodiment may be an endless belt or an endless belt, and they may be a single-layer belt composed only of an imide-based resin layer, or other layers may be further added. It may be a belt having a laminated structure.

[Unmodified imide resin (A): Component (A)]

The unmodified imide resin (A) of the present embodiment indicates an unmodified imide resin. Here, the imide resin refers to a resin including a structural unit having an imide bond. The kind of imide resin is not particularly limited, and examples of the imide resin include polyimide resin, polyamide imide resin, polyether imide resin, and the like, and these may be used alone. More than one species may be used in combination.
The unmodified imide resin (A) preferably includes at least one of a polyimide resin and a polyetherimide resin, more preferably a polyetherimide resin, from the viewpoint of improving the bending durability of the belt.

(Polyimide resin)
Examples of the polyimide resin include an imidized product of polyamic acid (polyimide resin precursor) which is a polymer of tetracarboxylic dianhydride and a diamine compound. Specifically, the polyimide resin is obtained by polymerizing equimolar amounts of tetracarboxylic dianhydride and diamine compound in a solvent to obtain a polyamic acid solution, and imidizing the polyamic acid. Can be mentioned.

  As a polyimide resin, resin which has a structural unit shown by the following general formula (I) is mentioned, for example.

(In the general formula (I), R ¹ is a tetravalent organic group, and an aromatic group, an aliphatic group, a cyclic aliphatic group, a group in which an aromatic group and an aliphatic group are combined, or they are substituted. R ² is a divalent organic group, such as an aromatic group, an aliphatic group, a cyclic aliphatic group, an aromatic group and an aliphatic group. A group in which group groups are combined, or a group in which they are substituted (for example, a residue of a diamine compound described later).

  Specific examples of the tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenyltetracarboxylic acid. Acid dianhydride, 2,3,3 ′, 4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid Dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2′-bis (3,4-dicarboxyphenyl) sulfonic dianhydride, perylene-3,4,9,10 -Tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride, etc. are mentioned.

On the other hand, specific examples of the diamine compound include 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,3′-dichlorobenzidine, 4,4′-diaminodiphenyl sulfide. 3,3′-diaminodiphenylsulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3′-dimethyl4,4′-biphenyldiamine, benzidine, 3,3′-dimethylbenzidine 3,3′-dimethoxybenzidine, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylpropane, 2,4-bis (β-aminotert-butyl) toluene, bis (p-β-amino- Tert-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis p- (1,1-dimethyl-5-amino-pentyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane , Hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1 , 2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2, 17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, _{piperazine, H 2 N (CH 2)} 3 O (CH 2) 2 O (CH 2) NH 2, H 2 N (CH 2) 3 S (CH 2) 3 NH 2, H 2 N (CH 2) 3 N _{(CH 3) 2 (CH 2} ) 3 NH 2 and the like.

(Polyamideimide resin)
Examples of the polyamideimide resin include a polymer of a trivalent carboxylic acid (tricarboxylic acid) having an acid anhydride group and an isocyanate or a diamine.
As the tricarboxylic acid, trimellitic anhydride and derivatives thereof are preferable. In addition to tricarboxylic acid, tetracarboxylic dianhydride, aliphatic dicarboxylic acid, aromatic dicarboxylic acid and the like may be used in combination.

  As the isocyanate, 3,3′-dimethylbiphenyl-4,4′-diisocyanate, 2,2′-dimethylbiphenyl-4,4′-diisocyanate, biphenyl-4,4′-diisocyanate, biphenyl-3,3′- Diisocyanate, biphenyl-3,4'-diisocyanate, 3,3'-diethylbiphenyl-4,4'-diisocyanate, 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4 , 4′-diisocyanate, 2,2′-dimethoxybiphenyl-4,4′-diisocyanate, naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate and the like. Examples of the diamine include compounds having the same structure as the above isocyanate and having an amino group instead of an isocyanato group.

(Polyetherimide resin)
Examples of the polyetherimide include those obtained by a polymerization reaction between a dicarboxylic dianhydride containing an ether bond and a diamine. That is, examples of the polyetherimide include a polyetherimide having at least a repeating unit structure derived from a dicarboxylic dianhydride containing an ether bond and a diamine.

  Examples of the dicarboxylic acid non-hydrate containing an ether bond include 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propane dianhydride, 4,4′-bis (3,4). Dicarboxyphenoxy) diphenyl ether dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) benzophenone dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfone dianhydride, 2,2-bis [4- (2,3-dicarboxyphenoxy) phenyl] propane dianhydride, 4,4'- Bis (2,3-dicarboxyphenoxy) diphenyl ether dianhydride, 4,4'-bis (2,3-dicarboxyphenoxy) diphenyl sulfide 4,4′-bis (2,3-dicarboxyphenoxy) benzophenone dianhydride, 4,4′-bis (2,3-dicarboxyphenoxy) diphenylsulfone dianhydride, 4- (2,3- Dicarboxyphenoxy) -4 '-(3,4-dicarboxyphenoxy) diphenyl-2,2-propane dianhydride, 4- (2,3-dicarboxyphenoxy) -4'-(3,4-dicarboxy Phenoxy) diphenyl ether dianhydride, 4- (2,3-dicarboxyphenoxy) -4 '-(3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4- (2,3-dicarboxyphenoxy) -4 '-(3,4-Dicarboxyphenoxy) benzophenone dianhydride and 4- (2,3-dicarboxyphenoxy) -4'-(3,4-dicarboxyl Phenoxy) diphenyl sulfone dianhydride, and the like. These dicarboxylic dianhydrides may be used individually by 1 type, and may use together 2 or more types selected among them.

  Examples of the diamine include aliphatic diamines, alicyclic diamines, aromatic diamines, aromatic diamines containing a heterocyclic ring, and the like.

The diamine is not particularly limited as long as it is a diamine compound having two amino groups in the molecular structure.
Examples of the diamine include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, 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, 4,4′-diaminobenzanilide, 3,5-diamino-3′-trifluoromethylbenzanilide, 3,5-diamino-4′-trifluoromethylbenzanilide, 3,4′-diaminodiphenyl ether, 2,7-di Minofluorene, 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-a Nophenyl) fluorene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2-trifluoro) Aromatic diamines such as methylphenoxy) phenyl] hexafluoropropane, 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl; aromatic rings such as diaminotetraphenylthiophene An aromatic diamine having two bonded amino groups and a hetero atom other than the nitrogen atom of the amino group; 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octa Methylenediamine, nonamethylenediamine, 4,4-diaminoheptamethyle Diamine, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene cyclopentadienylide diamine, hexahydro-4,7-meth Noin mite range diamine, tricyclo [6,2,1,0 ^2.7] - undecylenic Examples thereof include aliphatic diamines such as dimethyldiamine and 4,4′-methylenebis (cyclohexylamine), and alicyclic diamines. These diamines may be used alone or in combination of two or more selected from them.

  The content of the unmodified imide resin (A) is preferably 20% by mass or more and 80% by mass or less, and preferably 40% by mass or more and 60% by mass or less with respect to the imide resin layer, from the viewpoint of improving the bending durability of the belt. More preferably.

[Siloxane-modified imide resin (B): component (B)]
The siloxane-modified imide resin (B) is an imide resin obtained by modifying an imide resin with a silicone resin and having a siloxane bond. The imide resin to be modified is as described above.
The silicone resin can be selected from known silicone resins, such as methyl straight silicone resin, methylphenyl straight silicone resin, acrylic resin modified silicone resin, ester resin modified silicone resin, epoxy resin modified silicone resin, alkyd resin modified silicone resin In addition, a dimethylsiloxane resin is particularly preferable from the viewpoint of ease of processing into an imide resin.

The amount of modification of the siloxane-modified imide resin (B) is preferably 40% by mass or more and 90% by mass or less, and preferably 50% by mass or more and 80% by mass with respect to the entire siloxane-modified imide resin from the viewpoint of improving the bending durability of the belt. % Or less is more preferable.
The amount of modification of the siloxane-modified imide resin is the amount of siloxane group relative to the molecular weight of the entire siloxane-modified imide resin.

  The belt according to the present embodiment includes the siloxane-modified imide resin (B), so that the bending durability of the obtained belt is high due to the high degree of freedom of rotation of the siloxane group of the siloxane-modified imide resin (B). Will improve. In addition, since the terminal of the siloxane group has a methyl group, water and oil repellency are imparted to the obtained belt. Therefore, when the belt of this embodiment is applied to electrophotography, the toner component Adhesion can be reduced.

  As a specific example of the siloxane-modified imide resin (B), a siloxane-modified polyetherimide obtained by modifying a polyetherimide, which is one of the unmodified imide resins described above, with a silicone resin is preferable. And a reaction product of a dicarboxylic dianhydride with an amine-terminated organosiloxane and a diamine.

  Examples of commercially available siloxane-modified polyetherimide (a copolymer of a polyetherimide resin and a silicone resin) include SILTEM STM1500, 1600, and 1700 manufactured by SABIC Innovative Plastics.

  The content of the siloxane-modified imide resin (B) is preferably 20% by mass or more and 80% by mass or less, and preferably 40% by mass or more and 60% by mass or less with respect to the imide resin layer, from the viewpoint of improving the bending durability of the belt. More preferably.

-Content of component (B) with respect to component (A)-
The content of the siloxane-modified imide resin (B) with respect to 100 parts by mass of the unmodified imide resin (A) is preferably 5 parts by mass or more and 50 parts by mass or less from the viewpoint of improving the bending durability of the belt. It is more preferable that the amount is not less than 40 parts by mass.

[Silica-treated conductive agent (C); component (C)]
The siloxane-treated conductive agent (C) refers to a conductive agent in which a siloxane group is added to the surface of the conductive agent by a surface coating treatment with a silicone resin.
The silicone resin can be selected from known silicone resins, such as methyl straight silicone resin, methylphenyl straight silicone resin, acrylic resin modified silicone resin, ester resin modified silicone resin, epoxy resin modified silicone resin, alkyd resin modified silicone resin In addition, a dimethylsiloxane resin is particularly preferable from the viewpoint of ease of processing into an imide resin.

  Examples of the conductive agent include carbon black; metals such as aluminum and nickel; metal oxides such as yttrium oxide and tin oxide; ionic conductive substances such as potassium titanate and potassium chloride; polyaniline, polypyrrole, polysulfone, and polyacetylene. Examples thereof include conductive polymers. Of these, carbon black is preferable from the viewpoints of dispersibility, conductivity, and economy. Carbon black is excellent in conductivity and can impart high conductivity even with a small content.

Examples of the carbon black include ketchen black, oil furnace black, channel black, acetylene black, and carbon black whose surface is oxidized (hereinafter referred to as “surface-treated carbon black”). Of these, surface-treated carbon black is preferable from the viewpoint of electrical resistance stability over time.
The surface-treated carbon black is obtained by adding, for example, a carboxyl group, a quinone group, a lactone group, a hydroxyl group or the like to the surface. Examples of the surface treatment method include an air oxidation method in which a reaction is caused by contact with air in a high temperature atmosphere, a method of reacting with nitrogen oxide or ozone at a normal temperature (for example, 22 ° C.), and air in a high temperature atmosphere. A method of oxidizing with ozone at a low temperature after oxidation is exemplified.

The average primary particle size of the conductive agent is preferably 5 nm to 50 nm, more preferably 10 nm to 30 nm, and particularly preferably 15 nm to 25 nm.
If the upper limit of the average primary particle diameter of the conductive agent is 50 nm or less, the dispersibility of the conductive agent can be sufficiently obtained in the imide resin layer, which is preferable because the surface smoothness of the belt is improved. On the other hand, the lower limit of the average primary particle diameter of the conductive agent is preferably 5 nm or more, and more preferably 10 nm or more from the viewpoint of suppressing aggregation during dispersion.

The average primary particle diameter of the conductive agent contained in the belt according to the present embodiment is measured by the following method.
First, a measurement sample having a thickness of 100 nm is collected from the obtained belt with a microtome, and this measurement sample is observed with a TEM (transmission electron microscope). Then, the diameter of a circle equal to the projected area of each of 50 conductive agents (conductive particles) is taken as the particle diameter, and the average value is taken as the average primary particle diameter.

  The content of the siloxane-treated conductive agent (C) is preferably 10% by mass or more and 40% by mass or less, and preferably 15% by mass or more and 30% by mass with respect to the imide-based resin layer from the viewpoint of improving the bending durability of the belt. The following is more preferable.

-Content of component (C) with respect to component (A)-
The content of the conductive agent (C) treated with siloxane with respect to 100 parts by mass of the unmodified imide resin (A) is preferably 10 parts by mass or more and 40 parts by mass or less from the viewpoint of improving the bending durability of the belt. More preferably, they are 15 to 30 mass parts.

-Mass ratio of component (C) to component (B)-
The mass ratio of the siloxane-treated conductive agent (C) to the siloxane-modified imide resin (B) is preferably 0.2 or more and 8.0 or less from the viewpoint of improving the bending durability of the belt, More preferably, it is 0.4 or more and 6.0 or less.

  The conductive agent (C) treated with siloxane is preferably pH 9.0 or lower, preferably pH 8.0 or lower, and more preferably pH 7.0 or lower, from the viewpoint of electrical resistance stability over time.

(Other ingredients)
The imide-based resin layer of the belt according to the present embodiment can include other components that are components other than the components described above.
For example, an antioxidant for preventing thermal deterioration of the belt, a surfactant for improving fluidity, a heat resistant anti-aging agent, and the like, in particular, known additives blended in the belt of the image forming apparatus. . In order to improve the strength, silicon-containing particles such as silicone powder and silicone oil-containing silica may be blended.
The content of other components is preferably 50% by mass or less and more preferably 25% by mass or less with respect to the imide resin layer.

-Thickness of imide resin layer-
The thickness of the imide resin layer can be appropriately adjusted according to the use of the belt, but is preferably 20 μm or more and 300 μm or less, more preferably 50 μm or more and 200 μm or less from the viewpoint of improving the bending durability of the belt. preferable.

  As an application of the belt according to the present embodiment, an endless belt in an image forming apparatus is first mentioned. Specifically, it is applied to belt members for transfer devices (for example, intermediate transfer belts, recording medium conveyance belts, primary transfer belts, secondary transfer belts, etc.), belt members for charging devices (for example, charging belts, etc.), and the like. . In addition, you may use these belt members as roll members (a roll member for transfer devices, a roll member for charging devices) by covering these belt members on rolls such as metal rolls and resin rolls.

  In addition to the endless belt for the image forming apparatus, the belt according to the present embodiment can be used for a cylindrical solar cell substrate or the like. In addition, for example, it can be used for a belt-like member such as a conveyance belt, a driving belt, a laminate belt, an electric insulating material, a pipe coating material, an electromagnetic wave insulating material, a heat source insulator, and an electromagnetic wave absorbing film.

  The endless belt for the image forming apparatus according to the present embodiment may be a belt composed of a single layer of the imide resin layer according to the present embodiment, and the imide resin layer according to the present embodiment as a base material. Further, it may be a laminated belt in which another layer is laminated on at least one of the outer peripheral surface side and the inner peripheral surface side.

  For example, the aspect which has an elastic layer (for example, silicone rubber layer), a surface layer (for example, fluorine-containing resin layer), etc. in the outer peripheral surface side of the imide-type resin layer which concerns on this embodiment as a base material may be sufficient.

(Belt manufacturing method)
The method for producing the tubular body according to the present embodiment is not particularly limited. For example, a mixed resin pellet containing an unmodified imide resin, a siloxane modified imide resin, and a siloxane-treated conductive agent is prepared, and melt extruded. By forming an imide resin layer, a belt including the imide resin layer can be manufactured.
The mixed resin pellet may be blended with each component according to the target surface resistivity, surface roughness, repeated bending durability, dimensional stability, and the like.

  Also, each resin pellet containing the conductive agent and each resin component is prepared separately, and each resin pellet is blended according to the target surface resistivity, surface roughness, repeated bending durability, dimensional stability, etc. Melt extrusion may be performed.

  As another manufacturing method, for example, a resin solution in which an unmodified imide resin, a siloxane modified imide resin, and a siloxane-treated conductive agent are dissolved in a polar solvent is prepared, and the resin solution is applied and applied. By forming a film, an imide resin layer can be formed, and a belt including the imide resin layer can be manufactured.

  Examples of polar solvents include N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N, N-diethylacetamide (DEAc), dimethyl sulfoxide ( DMSO), hexamethylene phosphoramide (HMPA), N-methylcaprolactam, N-acetyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone (N, N-dimethylimidazolidinone, DMI) and the like These may be used alone or in combination of two or more.

[Image forming apparatus]

  Next, the image forming apparatus according to the present embodiment will be described.

  The image forming apparatus according to the present embodiment includes an image holding member, a toner image forming unit that forms a toner image on the surface of the image holding member, and a transfer device, and a transfer unit that transfers the toner image onto the surface of a recording medium. And comprising.

  For example, an image is obtained by an image carrier, a charging unit that charges the surface of the image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the surface of the charged image carrier, and a developer containing toner. Developing means for developing the electrostatic latent image formed on the surface of the holding member to form a toner image, transfer means for transferring the toner image to the surface of the recording medium, and fixing means for fixing the toner image to the recording medium; And a belt member or a roll member for the transfer device may include a belt for the image forming apparatus according to this embodiment.

  The image forming apparatus according to the present embodiment will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram illustrating a configuration of an image forming apparatus according to the present embodiment. Note that the belt for the image forming apparatus according to the present embodiment is applied as the intermediate transfer belt.

  As shown in FIG. 1, the image forming apparatus 100 according to the present embodiment is an intermediate transfer type image forming apparatus generally called a tandem type, for example, and a plurality of toner images of respective color components are formed by an electrophotographic system. Image forming units 1Y, 1M, 1C, and 1K, and a primary transfer unit 10 that sequentially transfers (primary transfer) the color component toner images formed by the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 15. The secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 onto the paper K that is a recording medium, and the fixing that fixes the secondary transferred image onto the paper K. Device 60. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).

  Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 100 includes a photoconductor 11 that rotates in the arrow A direction as an example of an image holding body that holds a toner image formed on the surface.

  A charger 12 for charging the photosensitive member 11 is provided around the photosensitive member 11 as an example of a charging unit, and a laser exposure device for writing an electrostatic latent image on the photosensitive member 11 as an example of a latent image forming unit. 13 (the exposure beam is indicated by Bm in the figure) is provided.

  Further, around the photosensitive member 11, as an example of a developing unit, a developing device 14 that accommodates each color component toner and visualizes the electrostatic latent image on the photosensitive member 11 with the toner is provided. A primary transfer roll 16 for transferring the color component toner images formed thereon onto the intermediate transfer belt 15 by the primary transfer unit 10 is provided.

  Further, a photoconductor cleaner 17 for removing residual toner on the photoconductor 11 is provided around the photoconductor 11, and a charger 12, a laser exposure device 13, a developing device 14, a primary transfer roll 16, and a photoconductor cleaner. Seventeen electrophotographic devices are sequentially arranged along the rotation direction of the photoconductor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15. Has been.

The intermediate transfer belt 15 that is an intermediate transfer member is formed so that the volume resistivity is, for example, 1 × 10 ⁶ Ωcm or more and 1 × 10 ¹⁴ Ωcm or less, and the thickness thereof is configured to be, for example, about 0.1 mm. Yes.

  The intermediate transfer belt 15 is circulated and driven (rotated) at various speeds in the direction B shown in FIG. 1 by various rolls. As these various rolls, a drive roll 31 that is driven by a motor (not shown) having excellent constant speed to rotate the intermediate transfer belt 15, and the intermediate transfer belt 15 that extends substantially linearly along the arrangement direction of the respective photoreceptors 11. A support roll 32 for supporting the intermediate transfer belt 15, a tension applying roll 33 that functions as a correction roll that applies tension to the intermediate transfer belt 15 and prevents meandering of the intermediate transfer belt 15, a back roll 25 provided in the secondary transfer unit 20, an intermediate A cleaning back roll 34 is provided in a cleaning unit that scrapes off residual toner on the transfer belt 15.

  The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 is placed in pressure contact with the photoreceptor 11 with the intermediate transfer belt 15 in between. Further, the primary transfer roll 16 has a voltage (primary polarity) opposite to the toner charging polarity (negative polarity; the same applies hereinafter). Transfer bias) is applied. As a result, the toner images on the respective photoconductors 11 are sequentially electrostatically attracted to the intermediate transfer belt 15 so that the superimposed toner images are formed on the intermediate transfer belt 15.

  The secondary transfer unit 20 includes a back roll 25 and a secondary transfer roll 22 disposed on the toner image holding surface side of the intermediate transfer belt 15.

The back roll 25 is formed so that the surface resistivity is 1 × 10 ⁷ Ω / □ or more and 1 × 10 ¹⁰ Ω / □ or less, and the hardness is, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd. The same). The back roll 25 is disposed on the back side of the intermediate transfer belt 15 to constitute a counter electrode of the secondary transfer roll 22, and a metal power supply roll 26 to which a secondary transfer bias is stably applied is disposed in contact. ing.

On the other hand, the secondary transfer roll 22 is a cylindrical roll having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less. The secondary transfer roll 22 is placed in pressure contact with the back roll 25 with the intermediate transfer belt 15 interposed therebetween. Further, the secondary transfer roll 22 is grounded and a secondary transfer bias is formed between the secondary transfer roll 22 and the back roll 25, and the secondary transfer roll 22 is grounded. The toner image is secondarily transferred onto the paper K conveyed to the transfer unit 20.

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be able to contact and separate.

  The intermediate transfer belt 15, the primary transfer unit 10 (primary transfer roll 16), and the secondary transfer unit 20 (secondary transfer roll 22) correspond to an example of a transfer unit.

  On the other hand, on the upstream side of the yellow image forming unit 1Y, a reference sensor (home position sensor) 42 that generates a reference signal serving as a reference for taking image forming timings in the image forming units 1Y, 1M, 1C, and 1K. It is arranged. Further, an image density sensor 43 for adjusting image quality is disposed on the downstream side of the black image forming unit 1K. The reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. In response to an instruction from the control unit 40 based on the recognition of the reference signal, each image forming unit 1Y, 1M, 1C, and 1K are configured to start image formation.

  Further, in the image forming apparatus according to the present embodiment, as a transport unit that transports the paper K, the paper storage unit 50 that stores the paper K, and the paper K accumulated in the paper storage unit 50 is taken out at a predetermined timing. A paper feed roll 51 that transports the paper K, a transport roll 52 that transports the paper K fed by the paper feed roll 51, a transport guide 53 that feeds the paper K transported by the transport roll 52 to the secondary transfer unit 20, and a secondary transfer A conveyance belt 55 that conveys the sheet K conveyed after the secondary transfer by the roll 22 to the fixing device 60 and a fixing entrance guide 56 that guides the sheet K to the fixing device 60 are provided.

  Next, a basic image forming process of the image forming apparatus according to the present embodiment will be described.

  In the image forming apparatus according to the present embodiment, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is subjected to image processing by an image processing device (not shown), and then the image forming unit 1Y. , 1M, 1C, 1K, image forming work is executed.

  In the image processing apparatus, input reflectance data is subjected to image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame erasing, color editing, and moving editing. Is done. The image data that has undergone image processing is converted into color material gradation data of four colors, Y, M, C, and K, and is output to the laser exposure unit 13.

  The laser exposure unit 13 irradiates each of the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K with, for example, an exposure beam Bm emitted from a semiconductor laser in accordance with the input color material gradation data. . In each of the photoreceptors 11 of the image forming units 1Y, 1M, 1C, and 1K, the surface is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure unit 13 to form an electrostatic latent image. The formed electrostatic latent images are developed as toner images of respective colors Y, M, C, and K by the respective image forming units 1Y, 1M, 1C, and 1K.

  The toner images formed on the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 in the primary transfer unit 10 where the photoconductors 11 and the intermediate transfer belt 15 are in contact with each other. The More specifically, in the primary transfer portion 10, a voltage (primary transfer bias) having a polarity opposite to the toner charging polarity (minus polarity) is applied to the base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner image. Are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

  After the toner images are sequentially primary transferred onto the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is conveyed to the secondary transfer unit 20. When the toner image is conveyed to the secondary transfer unit 20, the conveyance unit rotates the paper feed roll 51 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20. A size paper K is supplied. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52, and reaches the secondary transfer unit 20 through the transport guide 53. Before reaching the secondary transfer unit 20, the sheet K is temporarily stopped, and an alignment roll (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 15 that holds the toner image. And the position of the toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the sheet K conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) having the same polarity as the toner charging polarity (negative polarity) is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Is done. The unfixed toner image held on the intermediate transfer belt 15 is collectively electrostatically transferred onto the paper K in the secondary transfer unit 20 pressed by the secondary transfer roll 22 and the back roll 25. The

  Thereafter, the sheet K on which the toner image has been electrostatically transferred is conveyed as it is while being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and is conveyed downstream of the secondary transfer roll 22 in the sheet conveyance direction. It is conveyed to the belt 55. The transport belt 55 transports the paper K to the fixing device 60 in accordance with the optimal transport speed in the fixing device 60. The unfixed toner image on the paper K conveyed to the fixing device 60 is fixed on the paper K by receiving a fixing process with heat and pressure by the fixing device 60. Then, the sheet K on which the fixed image is formed is conveyed to a paper discharge container (not shown) provided in the discharge unit of the image forming apparatus.

  On the other hand, after the transfer to the paper K is completed, the residual toner remaining on the intermediate transfer belt 15 is conveyed to the cleaning unit as the intermediate transfer belt 15 rotates, and is cleaned by the cleaning back roll 34 and the intermediate transfer belt cleaner 35. It is removed from the intermediate transfer belt 15.

  Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and various modifications, changes, and improvements can be made.

<Example 1>
-Preparation of mixed resin pellets-
100 parts by mass of a polyetherimide resin ("ULTEM1010V", manufactured by Savic) as an unmodified imide resin, and 10 parts by mass of a siloxane modified polyetherimide resin ("Siltem 1500", dimethylsiloxane modified, siloxane modified) as a siloxane modified imide resin 50 mass%, manufactured by Savic Co., Ltd.) and 20 parts by mass of siloxane-treated carbon black (“OTS-8 (trade name)”, dimethylsiloxane modified, manufactured by Daito Kasei Co., Ltd.) were used as the siloxane-treated conductive agent.
First, an unmodified imide-based resin and a siloxane-modified imide-based resin were blended in advance using a mixing mixer so as to have the above-mentioned blending amount to obtain a blended resin composition.

  Using a biaxial extrusion melt kneader (biaxial melt kneading extruder L / D60, manufactured by Parker Corporation), the blended resin composition is subjected to siloxane-treated carbon black in a side feed or the like in the melted resin composition. A predetermined amount was blended, melt-kneaded, and the kneaded melt was placed in a water bath, cooled and solidified, and cut into a predetermined size to obtain mixed resin pellets.

-Production of endless belt-
The mixed resin pellets were put into a uniaxial melt extruder (L / D24, melt extrusion apparatus (manufactured by Mitsuba Seisakusho)) (heating temperature 340 ° C.) and melt extruded from the gap between the mold die and the nipple set to 330 ° C. The outer surface of the cylindrical inner sizing die was brought into contact with the inner peripheral surface of the molten resin, cooled, and then cut into a predetermined width to obtain an endless belt having an average film thickness of 120 μm.

<Example 2>
An endless belt was prepared in the same manner as in Example 1 except that 30 parts by mass of a siloxane-modified polyetherimide resin (“Siltem 1500”, manufactured by Savic) was used as the siloxane-modified imide resin in the preparation of the mixed resin pellets.

<Example 3>
An endless belt was prepared in the same manner as in Example 1 except that 50 parts by mass of a siloxane-modified polyetherimide resin (“Siltem 1500”, manufactured by Savic) was used as the siloxane-modified imide resin in the preparation of the mixed resin pellets.

<Example 4>
In preparation of mixed resin pellets, polyimide resin (“Aurum (trade name)”, manufactured by Mitsui Chemicals) is used as an unmodified imide resin, and siloxane-modified polyetherimide resin (“Siltem 1500”, manufactured by Subic) is 20 mass. An endless belt was produced in the same manner as in Example 1 except that the portion was used.

<Example 5>
An endless belt was produced in the same manner as in Example 2 except that 30 parts by mass of siloxane-treated carbon black was used as the siloxane-treated conductive agent in producing the mixed resin pellets.

<Comparative Example 1>
In the production of the mixed resin pellet, instead of the blended resin composition, an unmodified imide-based polyetherimide resin ("ULTEM1010V", manufactured by Savic Co., Ltd.) having only 100 parts by mass is used. An endless belt was produced in the same manner as in Example 1 except that 15 parts by mass of carbon black not treated with siloxane (“Monark 880 (trade name)”, manufactured by CABOT) was used in place of the treated carbon black.

<Comparative Example 2>
In preparation of mixed resin pellets, 35 parts by mass of unmodified polyetherimide resin (“ULTEM1010V”, manufactured by Subic) was used in place of siloxane-modified resin imide, and siloxane-treated carbon black was used as a siloxane-treated conductive agent. An endless belt was produced in the same manner as in Example 1 except that 17 parts by mass was used.

<Comparative Example 3>
In preparation of mixed resin pellets, 35 parts by mass of unmodified polyetherimide resin (“ULTEM1010V”, manufactured by Subic) was used instead of siloxane-modified resin imide, and siloxane-treated carbon black was used instead of siloxane-treated carbon black. An endless belt was obtained in the same manner as in Example 1 except that 22 parts by mass of carbon black (“Monark 880 (trade name)” manufactured by CABOT) was used.

[Evaluation]
The following evaluation was implemented about the endless belt manufactured in each case.

-Repeated bending durability (MIT test)-
Test method: JIS-P8115: 2001 compliant (MIT test machine, sample width 15 mm, tensile load 1 kg until endurance)
The endless belt obtained in each example was cut into a strip-like sample having a width of 15 mm and a length of 200 mm in the circumferential direction, fixed at both ends and applied with a tensile tension of 1 kgf, and left and right 90 with the terminal of the curvature shape R0.38 as a fulcrum. It was repeatedly bent (bent) in the ° direction. At this time, the number of times until the sample broke was evaluated as the number of bending resistances. Here, the above test was performed in a normal temperature and normal humidity (temperature 22 ° C., humidity 55% RH) environment.

−Surface resistivity (before image output) −
The surface resistivity (logΩ / □) of the endless belt obtained in each example was measured with an Advantest microammeter (UR probe / 100 V / load 2 kg / 10 seconds). Here, the measurement was performed in an environment of a temperature of 22 ° C. and a humidity of 55% RH.

−Surface resistivity (after image output) −
The endless belt obtained in each example was mounted as an intermediate transfer belt in an image forming apparatus “DocuPrint C2250” manufactured by Fuji Xerox Co., Ltd.
Then, in a low-temperature and low-humidity environment of 10 ° C./10% RH, the surface resistivity (log Ω / □) of the endless belt (intermediate transfer belt) after outputting 50,000 sheets is the surface resistivity before image output. It measured similarly.

−Surface roughness (before image output) −
The surface roughness Ra (μm) of the endless belt obtained in each example was measured according to JIS-B0601: 2001 using Surfcom (manufactured by Tokyo Seimitsu Co., Ltd.).

−Surface roughness (after image output) −
The endless belt obtained in each example was mounted as an intermediate transfer belt in an image forming apparatus “DocuPrint C2250” manufactured by Fuji Xerox Co., Ltd.
Then, in an environment of a temperature of 20 to 25 ° C. and a relative humidity of 50 to 55%, the surface roughness Ra (μm) of the belt (intermediate transfer belt) after outputting 50,000 sheets of images is surface resistance before image output. Measured as rate

-Dimensional stability due to moisture absorption (elongation rate)-
The endless belt obtained in each example was measured for the amount of expansion and contraction before and after the environmental change in a constant temperature bath in which an environment of 45 ° C. and 90% RH and an environment of 45 ° C. and 10% RH could be alternately set. The measurement method was as follows.
Take a sample with a long side of 30 cm x a short side of 2.5 cm from the endless belt obtained in each example, and measure the long side dimension of the sample after suspending the sample in an environment of 45 ° C and 90% RH for 48 hours. Then, the dimension of the long side of the sample after measurement was suspended for 48 hours in an environment of 45 ° C. and 10% RH was measured. The ratio of the dimension of the long side of the sample after being suspended for 48 hours in an environment of 45 ° C. and 10% RH to the dimension of the long side of the sample after being suspended for 48 hours in an environment of 45 ° C. and 90% RH The elongation rate was used.

-Cleaning durability test during continuous use-
The endless belt obtained in each example is used as an intermediate transfer belt in an image forming apparatus “C2250 manufactured by Fuji Xerox Co., Ltd.” in a low-temperature and low-humidity environment of 10 ° C./10% RH (paper on the surface of the intermediate transfer belt during transfer) In an environment where discharge due to peeling is likely to occur), after continuous output of 50,000 images, the image quality of halftone (30% magenta) images was evaluated. Further, the surface resistivity (normal temperature and normal humidity (22 ° C. and 55 RH%), applied voltage of 100 V) of the endless belt (intermediate transfer belt) before and after the continuous output of 50,000 images was measured.
Here, the image quality was evaluated according to the following criteria.
A: No decrease in image density B: Slight decrease in image density C: Reduction in image density (unacceptable level)

-Evaluation of the effect of moisture absorption dimensional change on image formation-
The endless belt obtained in each example was mounted as an intermediate transfer belt in an image forming apparatus “DocuPrint C2250” manufactured by Fuji Xerox Co., Ltd. After leaving for 100 hours in an environment of 40 ° C. and 95% RH, a halftone image (30% magenta) is continuously output on A5 paper in an environment of 10 ° C. and 10% RH, and 1,000 images are output. The effect on image quality due to deformation of the intermediate transfer belt was confirmed. Here, the tenth image and the 1,000th image were visually compared, and the image quality was evaluated according to the following criteria.
A: No decrease in image density B: Slight decrease in image density C: Reduction in image density (unacceptable level)

  Table 1 below shows the blending amounts (mass ratio) and evaluation results of the resin and conductive agent used in each example.

From the above results, the endless belt of this example was excellent in bending durability compared to the endless belt of the comparative example.
In the endless belt of this example, no significant decrease in the surface resistivity of the endless belt was observed before and after image output, and no surface roughness occurred on the belt. On the other hand, in the belt of the comparative example, it can be seen that the surface resistivity of the belt is remarkably lowered before and after the image is output, and the surface is roughened.

Further, in the evaluation of the dimensional stability due to moisture absorption, the endless belt of this example had a slight dimensional change due to moisture absorption, but the endless belt of the comparative example showed remarkable elongation due to moisture absorption.
Further, in the endurance cleaning test, the endless belt of this example did not show a decrease in image density, but the endless belt of the comparative example has image white streaks caused by poor cleaning due to surface roughness of the endless belt, and image Halftone image density spots were observed due to a significant decrease in surface resistance before and after output.
In addition, as for the image evaluation result in the actual machine that the moisture absorption dimension change has on the image formation, the belt of this example did not appear to have an effect on the image, but the endless belt of the comparative example had an image quality defect. The belt of the example can be said to be excellent in image quality in image formation under moisture absorption.
Therefore, it can be seen that the endless belt obtained in this example is excellent in dimensional stability due to moisture absorption, and has good toner cleaning and good cleaning properties.

1Y, 1M, 1C, 1K Image forming unit 10 Primary transfer unit 11 Photoconductor 12 Charger 13 Laser exposure unit 14 Developer 15 Intermediate transfer belt 16 Primary transfer roll 17 Photoconductor cleaner 20 Secondary transfer unit 22 Secondary transfer roll 25 Back roll 26 Power supply roll 31 Drive roll 32 Support roll 33 Tension applying roll 34 Cleaning back roll 35 Intermediate transfer belt cleaner 40 Control unit 42 Reference sensor 43 Image density sensor 50 Paper storage unit 51 Paper feed roll 52 Transport roll 53 Transport guide 55 Transport Belt 56 Fixing entrance guide 60 Fixing apparatus 100 Image forming apparatus

Claims (12)

Unmodified imide resin (A),
A siloxane-modified imide resin (B);
A siloxane-treated conductive agent (C);
A belt having an imide resin layer containing   The belt according to claim 1, wherein the siloxane-treated conductive agent (C) is siloxane-treated carbon black.   The belt according to claim 1 or 2, wherein the siloxane treatment of the siloxane-treated conductive agent (C) is a dimethylsiloxane treatment.   The belt according to any one of claims 1 to 3, wherein the siloxane-modified imide resin (B) is a dimethylsiloxane-modified imide resin.   5. The content of the siloxane-modified imide resin (B) with respect to 100 parts by mass of the unmodified imide resin (A) is 5 parts by mass or more and 50 parts by mass or less. 5. Belt.   The belt according to claim 5, wherein the content of the siloxane-modified imide resin (B) is 10 parts by mass or more and 40 parts by mass or less.   5. The content of the conductive agent (C) treated with siloxane with respect to 100 parts by mass of the unmodified imide resin (A) is 10 parts by mass or more and 40 parts by mass. 5. Belt. The belt according to claim 7, wherein the content of the siloxane-treated conductive agent (C) is 15 parts by mass or more and 30 parts by mass or less.   The belt according to any one of claims 5 to 8, wherein a mass ratio of the siloxane-treated conductive agent (C) to the siloxane-modified imide resin (B) is 0.2 or more and 8.0 or less. .   An endless belt comprising the belt according to any one of claims 1 to 9.   An intermediate transfer belt comprising the endless belt according to claim 10.   An image forming apparatus comprising the endless belt according to claim 10.