JP7070077B2 - Belts, endless belts, intermediate transfer belts, and image forming equipment - Google Patents

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 holder is transferred to the surface of a recording medium and fixed on the recording medium to form an image. Will be 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. A resin composition containing a resin such as an imide-based resin is used for forming such a belt.

For example, Patent Document 1 states that "an endless tubular belt containing a siloxane-modified polyimide resin or a siloxane-modified polyamide-imide resin, the front surface side of the endless tubular belt has the property of polyimide, and the back surface side thereof has the property of silicone. Moreover, the endless tubular belt is characterized in that it is an inclined material whose physical properties continuously change in the thickness direction from the front surface side to the back surface side. "

Patent Document 2 states that "with respect to 100 parts by weight of a polyether aromatic imide resin, 3 parts by weight to 80 parts by weight of a conductive filler is contained, and the volume resistivity is 1 x 104 Ω · cm or more, 1 x 1013 Ω ·. A polyether aromatic imide-based resin composition characterized by having an antistatic property of less than cm is disclosed.

Patent Document 3 states that "a semi-conductive polyimide belt containing a silicon-modified polyimide having a molar content of a silicon-containing repeating unit of 0.1 / 100 to 15/100, wherein the belt has a tensile coefficient of friction of 2000 MPa or more. , A semi-conductive polyimide belt in which the coefficient of friction of the outer surface of the belt is less than 0.4 and the ratio of the coefficient of friction between the inner surface and the outer surface of the belt (inner surface / outer surface ratio) is 1.1 or more is disclosed.

Japanese Unexamined Patent Publication No. 2007-072197 Japanese Unexamined Patent Publication No. 2004-182833 Japanese Unexamined Patent Publication No. 2008-197365

An object of the present invention is to improve bending durability in a belt having an imide-based resin layer containing an unmodified imide-based resin, a siloxane-modified imide-based resin, and a conductive agent, as compared with the case where the conductive agent is an untreated conductive agent. To provide an excellent belt.

The above problem is solved by the following means.

<1>
A belt having an imide-based resin layer containing an unmodified imide-based resin (A), a siloxane-modified imide-based 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-based resin (B) is a dimethylsiloxane-modified imide-based resin.
<5>
Described in any one of <1> to <4>, wherein the content of the siloxane-modified imide-based resin (B) with respect to 100 parts by mass of the unmodified imide-based resin (A) is 5 parts by mass or more and 50 parts by mass or less. 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>
Described in any one of <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 the 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 made of the belt according to any one of <1> to <9>.
<11>
An intermediate transfer belt made of the endless belt according to <10>.
<12>
An image forming apparatus including the endless belt according to <10>.

According to the inventions <1> to <4>,
In a belt having an imide-based resin layer containing an unmodified imide-based resin, a siloxane-modified imide-based resin, and a conductive agent, a belt having excellent bending durability as compared with the case where the conductive agent is an untreated conductive agent is provided. ..

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

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

A belt having excellent bending durability is provided 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.

According to the inventions <10> to <12>,
A belt having an imide-based resin layer containing an unmodified imide-based resin, a siloxane-modified imide-based resin, and a conductive agent, which has excellent bending durability as compared with the case where an untreated conductive agent is applied as the conductive agent. An image forming apparatus including a belt, an intermediate transfer belt including an endless belt, and the endless belt is provided.

It is a schematic block diagram which shows an example of the image forming apparatus which concerns on this embodiment.

Hereinafter, embodiments that are an example of the present invention will be described. The reference numerals may be omitted in the following description.

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

By adopting the above configuration for the belt of the present embodiment, a belt having excellent bending durability can be obtained. The reason is not clear, but it is presumed as follows.

Conventionally, when a belt having an imide-based resin layer having excellent dimensional stability is applied 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 the required 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 cracks may occur in the belt. When the belt is cracked, the strength is not sufficient against the repeated deformation stress when the belt is used repeatedly, and the bending durability may be inferior.
Furthermore, since the conductive agent is mixed in the resin layer of the belt, the elongation of the belt is suppressed against the deformation stress, and a high load is always applied to the belt, so that it can be used for a long time from the viewpoint of durability. It was difficult.
On the other hand, the belt of the present embodiment has an imide-based resin layer containing an unmodified imide-based resin (A), a siloxane-modified imide-based resin (B), and a siloxane-treated conductive agent (C). are doing.
The siloxane-modified imide-based resin (B) contained in this imide-based resin layer has an imide group and a siloxane-binding group. Further, the unmodified imide-based resin (A) contained in the imide-based resin layer has an imide group, and the siloxane-treated conductive agent (C) has a siloxane-binding group.
Therefore, the siloxane-modified imide-based resin (B) has a high affinity with the unmodified imide-based resin (A) due to the affinity between those having an imide group, and the siloxane-modified imide-based resin (B) has a siloxane-binding group. The affinity with the conductive agent (C) is also high due to the affinity of.
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 of the present embodiment are well mixed with each other, and in particular, The siloxane-treated conductive agent (C) has a 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.
Further, 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 due to its molecular structure. It is considered that the belt of the present embodiment exhibits followability to repeated deformation stress and exhibits durability during long-term use.
From the above, it is presumed that in the present embodiment, a belt having excellent bending durability can be obtained.

The belt according to the present embodiment has an imide-based resin layer containing an unmodified imide-based resin (A), a siloxane-modified imide-based resin (B), and a siloxane-treated conductive agent (C).
With the above configuration, the belt according to the present 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 and cleaning defects are 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 of only an imide-based resin layer, or may further include other layers. It may be a belt having a laminated structure including the belt.

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

The unmodified imide-based resin (A) of the present embodiment indicates an unmodified imide-based resin. Here, the imide-based resin refers to a resin containing a structural unit having an imide bond. The type of the imide-based resin is not particularly limited, and examples of the imide-based resin include a polyimide resin, a polyamide-imide resin, a polyetherimide resin, and the like, and these may be used alone. More than seeds may be used together.
From the viewpoint of improving the bending durability of the belt, the unmodified imide resin (A) preferably contains at least one of a polyimide resin and a polyetherimide resin, and more preferably a polyetherimide resin.

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

Examples of the polyimide resin include resins having a structural unit represented by the following general formula (I).

(In the general formula (I), R ¹ is a tetravalent organic group, which is an aromatic group, an aliphatic group, a cyclic aliphatic group, a group combining an aromatic group and an aliphatic group, or a group thereof in which they are substituted. Group (eg, residues of tetracarboxylic acid dianhydride described below). R ² is a divalent organic group, aromatic group, aliphatic group, cyclic aliphatic group, aromatic group and fat. A group in which a group group is combined or a group in which they are substituted (for example, a residue of a diamine compound described later can be mentioned).

Specifically, the tetracarboxylic acid dianhydride is pyromellitic acid dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid. Acid dianhydride, 2,3,3', 4-biphenyltetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid Dianoxide, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) sulfonic acid dianhydride, perylene-3,4,9,10 -Tetracarboxylic acid dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, ethylene tetracarboxylic acid dianhydride and the like can be 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, and 4,4'-diaminodiphenyl sulfide. , 3,3'-diaminodiphenylsulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl 4,4'-biphenyldiamine, benzidine, 3,3'-dimethylbenzidine , 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylpropane, 2,4-bis (β-aminotri-butyl) toluene, bis (p-β-amino-) Tertiary 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-xylylene diamine, p-xylylene diamine, di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-Methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminoprovoxyetan, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine , 2,5-Dimethylheptamethylenediamine, 3-Methylheptamethylenediamine, 5-Methylnonamethylenediamine, 2,17-diaminoeicosadecan, 1,4-diaminocyclohexane, 1,10-diamino-1,10- Diaminedecane, 12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, piperazine, H2N ( _CH2 ) _{3O ( CH2} ) _2O ( _CH2 ) _NH2 , Examples thereof include 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 .

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

Examples of the isocyanate include 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-mentioned isocyanate and having an amino group instead of the isocyanato group.

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

Examples of the dicarboxylic acid anhydride containing an ether bond include 2,2-bis [4- (3,4-dicarboxyphenoxy) phenyl] propanedianhydride and 4,4'-bis (3,4-bis). Dicarboxyphenoxy) Diphenyl ether dianhydride, 4,4'-bis (3,4-dicarboxyphenoxy) diphenylsulfide 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) diphenylsulfide dianhydride, 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-dicarboxyphenoxy) diphenyl ether dianhydride, 4- (2,3-dicarboxy) Phenoxy) -4'-(3,4-dicarboxyphenoxy) diphenylsulfide dianhydride, 4- (2,3-dicarboxyphenoxy) -4'-(3,4-dicarboxyphenoxy) benzophenone dianhydride and Examples thereof include 4- (2,3-dicarboxyphenoxy) -4'-(3,4-dicarboxyphenoxy) diphenylsulfone dianhydride. These dicarboxylic acid dianhydrides may be used alone or in combination of two or more selected from them.

Examples of the diamine include an aliphatic diamine, an alicyclic diamine, an aromatic diamine, and an aromatic diamine containing a heterocycle.

The diamine is not particularly limited as long as it is a diamine compound having two amino groups in its molecular structure.
The diamine may be, for example, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylsulfide, 4,4'-Diaminodiphenylsulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) -1,3,3- Trimethylindan, 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindan, 4,4'-diaminobenzanilide, 3,5-diamino-3'-trifluoromethylbenzanilide, 3,5-Diamino-4'-trifluoromethylbenzanilide, 3,4'-diaminodiphenyl ether, 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-amino) Phenyl] 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-phenylene isopropylidene) bisaniline, 4,4'- (M-Phenylisopropyridene) 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; aromatics having two amino groups bonded to an aromatic ring such as diaminotetraphenylthiophene and heteroatoms other than the nitrogen atom of the amino groups. Diamine; 1,1-methoxylylene diamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylene Diamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadiene diamine, hexahydro-4,7-methanoin danirange methylenediamine, tricyclo [6,2 1,0 ^2.7 ] -Undecylenedimethyldiamine, aliphatic diamines such as 4,4'-methylenebis (cyclohexylamine), alicyclic diamines and the like can be mentioned. 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 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. It is more preferable to have.

[Siloxane-modified imide resin (B): component (B)]
The siloxane-modified imide-based resin (B) is an imide-based resin obtained by modifying the imide-based resin with a silicone resin and having a siloxane bond. The imide-based resin to be modified is as described above.
The silicone resin can be selected from known silicone resins, for example, 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. And rubber-based silicone resin, dimethylsiloxane resin is particularly preferable from the viewpoint of ease of processing into an imide-based resin.

The amount of modification of the siloxane-modified imide-based resin (B) is preferably 40% by mass or more and 90% by mass or less, and 50% by mass or more and 80% by mass with respect to the entire siloxane-modified imide-based 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-based resin is the amount of siloxane groups with respect to the total molecular weight of the siloxane-modified imide-based resin.

Since the belt according to the present embodiment contains the siloxane-modified imide-based resin (B), the bending durability of the belt obtained from the high degree of freedom of rotation of the siloxane group of the siloxane-modified imide-based resin (B) is obtained. Is improved. Further, since the terminal of the siloxane group has a methyl group, water repellency and oil repellency are imparted to the obtained belt. Therefore, when the belt of the present embodiment is applied to an electrophotographic application, it is a toner component. Adhesion can be reduced.

As a specific example of the siloxane-modified imide-based resin (B), a siloxane-modified polyetherimide obtained by modifying polyetherimide, which is one of the above-mentioned unmodified imide-based resins, with a silicone resin is preferable, and for example, aromatic. Examples thereof include a reaction product of a dicarboxylic acid dianhydride with an amine-terminated organosiloxane and a diamine.

Commercially available products of siloxane-modified polyetherimide (polymer of polyetherimide resin and silicone resin) include, for example, SABIC Innovative Plastics' SILTEM STM1500, 1600, 1700 and the like.

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

-Content of component (B) with respect to component (A)-
The content of the siloxane-modified imide-based resin (B) with respect to 100 parts by mass of the unmodified imide-based 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 40 parts by mass or more and 40 parts by mass or less.

[Siloxane-treated conductive agent (C); component (C)]
The siloxane-treated conductive agent (C) refers to a conductive agent in which a siloxane group is imparted to the surface of the conductive agent by surface coating treatment with a silicone resin.
The silicone resin can be selected from known silicone resins, for example, 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. And rubber-based silicone resin, dimethylsiloxane resin is particularly preferable from the viewpoint of ease of processing into an imide-based 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, polyacetylene and the like. Examples include conductive polymers. Of these, carbon black is preferable from the viewpoint of dispersibility, conductivity, and economy. Carbon black has excellent conductivity and can impart high conductivity even with a small content.

Examples of carbon black include Ketchen black, oil furnace black, channel black, acetylene black, and carbon black having an oxidized surface (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 imparting, for example, a carboxyl group, a quinone group, a lactone group, a hydroxyl group, or the like to the surface thereof. Examples of the surface treatment method include an air oxidation method in which the surface is reacted in contact with air in a high temperature atmosphere, a method in which the surface is reacted with nitrogen oxides and ozone at a normal temperature (for example, 22 ° C.), and air in a high temperature atmosphere. Examples thereof include a method of oxidizing with ozone at a low temperature after oxidation.

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

The average primary particle size 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 by a microtome, and this measurement sample is observed by a TEM (transmission electron microscope). Then, the diameter of a circle equal to the projected area of each of the 50 conductive agents (conductive particles) is defined as the particle diameter, and the average value thereof is defined 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 15% by mass or more and 30% by mass or less, based on 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 siloxane-treated conductive agent (C) 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. It is more preferably 15 parts by mass or more and 30 parts by mass or less.

-Mass ratio of component (C) to component (B)-
Further, 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. It is more preferably 0.4 or more and 6.0 or less.

From the viewpoint of electrical resistance stability over time, the siloxane-treated conductive agent (C) preferably has a pH of 9.0 or less, preferably a pH of 8.0 or less, and more preferably a pH of 7.0 or less.

(Other ingredients)
The imide-based resin layer of the belt according to the present embodiment may contain other components other than the above-mentioned components.
Examples thereof include antioxidants for preventing thermal deterioration of belts, surfactants for improving fluidity, heat-resistant aging inhibitors, and the like, and in particular, known additives to be blended in belts of image forming apparatus. .. Further, in order to improve the strength, silicon-containing particles such as silicone powder and silicone oil-containing silica may be blended.
The content of the other components is preferably 50% by mass or less, more preferably 25% by mass or less, based on the imide-based resin layer.

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

An endless belt in an image forming apparatus can be mentioned as an application of the belt according to the present embodiment. Specifically, it is applied to a belt member for a transfer device (for example, an intermediate transfer belt, a recording medium transfer belt, a primary transfer belt, a secondary transfer belt, etc.), a belt member for a charging device (for example, a charging belt, etc.), and the like. .. By further covering these belt members on rolls such as metal rolls and resin rolls, they may be used as roll members (roll members for transfer devices, roll members for charging devices).

In addition to the endless belt for the image forming apparatus, the belt according to the present embodiment can also be used as a base material for a cylindrical solar cell or the like. In addition, for example, it can be used for a conveyor belt, a drive belt, a laminated belt, an electric insulating material, a piping covering material, an electromagnetic wave insulating material, a heat source insulator, a belt-shaped member such as an electromagnetic wave absorbing film, and the like.

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

For example, an elastic layer (for example, a silicone rubber layer), a surface layer (for example, a fluorine-containing resin layer), or the like may be provided on the outer peripheral surface side of the imide-based resin layer according to the present embodiment as a base material.

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

In addition, resin pellets containing a conductive agent and each resin component separately are prepared, and each resin pellet is blended according to the target surface resistivity, surface roughness, repeated bending durability, dimensional stability, etc. You may perform melt extrusion.

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

As the polar solvent, for example, N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N, N-diethylacetamide (DEAc), dimethyl sulfoxide ( DMSO), hexamethylenephospholamide (HMPA), N-methylcaprolactam, N-acetyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone (N, N-dimethylimidazolidinone, DMI), etc. These may be used alone or in combination of two or more.

[Image forming device]

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

The image forming apparatus of the present embodiment includes an image holder, a toner image forming means for forming a toner image on the surface of the image holder, and a transfer device, and the transfer means for transferring the toner image to the surface of a recording medium. And.

For example, an image can be imaged by an image holder, a charging means for charging the surface of the image holder, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image holder, and a developer containing toner. A developing means for developing an electrostatic latent image formed on the surface of a holder to form a toner image, a transfer means for transferring the toner image to the surface of a recording medium, and a fixing means for fixing the toner image on the recording medium. , And as the belt member or roll member for the transfer device, there is an embodiment in which the belt for the image forming device according to the present embodiment is provided.

Hereinafter, the image forming apparatus according to this embodiment will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a configuration of an image forming apparatus according to the present embodiment. As the intermediate transfer belt, the belt for the image forming apparatus according to the present embodiment is applied.

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

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

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

Further, around the photoconductor 11, as an example of the developing means, a developer 14 in which toners of each color component are accommodated and an electrostatic latent image on the photoconductor 11 is visualized by the toner is provided, and the photoconductor 11 is provided. A primary transfer roll 16 is provided for transferring each color component toner image formed above to the intermediate transfer belt 15 by the primary transfer unit 10.

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 developer 14, a primary transfer roll 16, and a photoconductor cleaner are provided. 17 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 done.

The intermediate transfer belt 15, which is an intermediate transfer body, is formed so that the volume resistivity is, for example, 1 × 10 ⁶ Ω cm or more and 1 × 10 ¹⁴ Ω cm or less, and its thickness is configured to be, for example, about 0.1 mm. There is.

The intermediate transfer belt 15 is circulated (rotated) by various rolls in the B direction shown in FIG. 1 at a speed suitable for the purpose. As these various rolls, a drive roll 31 driven by a motor (not shown) having excellent constant speed to rotate the intermediate transfer belt 15, and an intermediate transfer belt 15 extending substantially linearly along the arrangement direction of each photoconductor 11. A support roll 32 that supports the intermediate transfer belt 15, a tension application roll 33 that functions as a correction roll that applies tension to the intermediate transfer belt 15 and prevents the intermediate transfer belt 15 from meandering, a back roll 25 provided on the secondary transfer unit 20, and an intermediate surface. It has a cleaning back roll 34 provided in a cleaning section for scraping off residual toner on the transfer belt 15.

The primary transfer unit 10 is composed of a primary transfer roll 16 arranged so as to face the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 is pressure-welded to the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween, and the primary transfer roll 16 has a voltage (primary) opposite to that of the toner charging polarity (minus polarity; the same applies hereinafter). Transfer bias) is applied. As a result, the toner image on each photoconductor 11 is sequentially electrostatically sucked onto the intermediate transfer belt 15, and the superimposed toner image is formed on the intermediate transfer belt 15.

The secondary transfer unit 20 includes a back surface roll 25 and a secondary transfer roll 22 arranged 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 Polymer Instruments Co., Ltd., or less. Similarly.) Is set. The back surface roll 25 is arranged on the back surface side of the intermediate transfer belt 15 to form a counter electrode of the secondary transfer roll 22, and the metal feeding roll 26 to which the secondary transfer bias is stably applied is contact-arranged. 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 Ω cm or less. Then, the secondary transfer roll 22 is pressure-welded to the back roll 25 with the intermediate transfer belt 15 interposed therebetween, and the secondary transfer roll 22 is grounded to form a secondary transfer bias with the back roll 25. 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, the intermediate transfer belt that cleans the surface of the intermediate transfer belt 15 by removing residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer. A cleaner 35 is provided so as to be detachable.

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 the transfer means.

On the other hand, on the upstream side of the yellow image forming unit 1Y, there is a reference sensor (home position sensor) 42 that generates a reference signal as a reference for taking the image forming timing in each image forming unit 1Y, 1M, 1C, 1K. It is arranged. Further, an image density sensor 43 for adjusting the image quality is arranged 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. According to an instruction from the control unit 40 based on the recognition of the reference signal, each image forming unit 1Y, 1M, 1C, 1K are configured to initiate image formation.

Further, in the image forming apparatus according to the present embodiment, as a transporting means for transporting the paper K, the paper accommodating unit 50 accommodating the paper K and the paper K accumulated in the paper accommodating unit 50 are taken out at predetermined timings. The paper feed roll 51 to be conveyed by the paper feed roll 51, the transfer roll 52 to convey the paper K fed by the paper feed roll 51, the transfer guide 53 to feed the paper K conveyed by the transfer roll 52 to the secondary transfer unit 20, and the secondary transfer. It includes a transport belt 55 that transports the paper K that is secondarily transferred by the roll 22 to the fixing device 60, and a fixing inlet guide 56 that guides the paper K to the fixing device 60.

Next, the 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, the image data output from an image reading device (not shown), a personal computer (PC) (not shown), or the like is subjected to image processing by an image processing device (not shown), and then the image forming unit 1Y. , 1M, 1C, 1K perform the image drawing work.

The image processing device performs image processing such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame erasing and color editing, and various image editing such as movement editing on the input reflectance data. Will be 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 device 13.

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

The toner image formed on the photoconductors 11 of the image forming units 1Y, 1M, 1C, and 1K is transferred onto the intermediate transfer belt 15 in the primary transfer unit 10 in which each photoconductor 11 and the intermediate transfer belt 15 are in contact with each other. Toner. More specifically, in the primary transfer unit 10, the primary transfer roll 16 applies a voltage having a charge polarity (negative polarity) and a reverse polarity (primary transfer bias) of the toner to the substrate of the intermediate transfer belt 15, and the toner image. Is sequentially superposed on the surface of the intermediate transfer belt 15, and the primary transfer is performed.

After the toner image is sequentially primary-transferred to 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 paper feed roll 51 rotates in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20, and the target is from the paper storage unit 50. Paper K of size is supplied. The paper K supplied by the paper feed roll 51 is conveyed by the transfer roll 52 and reaches the secondary transfer unit 20 via the transfer guide 53. Before reaching the secondary transfer unit 20, the paper K is temporarily stopped, and the alignment roll (not shown) rotates according to the movement timing of the intermediate transfer belt 15 in which the toner image is held, so that the paper K is formed. The position of the toner image is aligned with the position of the toner image.

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 paper K conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At that time, when a voltage (secondary transfer bias) having the same polarity as the charging polarity (minus polarity) of the toner is applied from the feeding roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back surface roll 25. Will be done. Then, the unfixed toner image held on the intermediate transfer belt 15 is electrostatically transferred onto the paper K collectively in the secondary transfer unit 20 pressurized by the secondary transfer roll 22 and the back surface roll 25. Toner.

After that, the paper K on which the toner image is electrostatically transferred is conveyed as it is in a state of being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and is provided on the downstream side of the secondary transfer roll 22 in the paper transfer direction. It is transported to the belt 55. The transport belt 55 transports the paper K to the fixing device 60 according to the optimum 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 being subjected to a fixing process by heat and pressure by the fixing device 60. Then, the paper K on which the fixed image is formed is conveyed to a paper ejection accommodating portion (not shown) provided in the ejection 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 conveyed to the cleaning section 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 embodiment is not limited to the above embodiment, and various modifications, changes, and improvements can be made.

<Example 1>
-Preparation of mixed resin pellets-
100 parts by mass of polyetherimide resin (“ULTEM1010V”, manufactured by Savik Co., Ltd.) 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-based resin. An amount of 50% by mass, manufactured by Savik 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, the unmodified imide-based resin and the siloxane-modified imide-based resin were blended in advance using a mixing mixer so as to have the above-mentioned blending amounts to obtain a blended resin composition.

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

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

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

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

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

<Comparative Example 1>
In the preparation of the mixed resin pellets, instead of the blended resin composition, a polyetherimide resin (“ULTEM1010V”, manufactured by Savik Co., Ltd.) which is an unmodified imide resin is used only by 100 parts by mass, and further, siloxane 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 (“Monark880 (trade name)”, manufactured by CABOT) was used instead of the treated carbon black.

<Comparative Example 2>
In the preparation of the mixed resin pellet, 35 parts by mass of an unmodified polyetherimide resin (“ULTEM1010V”, manufactured by Savik Co., Ltd.) was used instead of the siloxane-modified resinimide, and a siloxane-treated carbon black was used as the 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 the preparation of the mixed resin pellet, 35 parts by mass of an unmodified polyetherimide resin (“ULTEM1010V”, manufactured by Savik Co., Ltd.) was used instead of the siloxane-modified resinimide, and further, siloxane-treated instead of the 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 (“Monark880 (trade name)”, manufactured by CABOT) was used.

[evaluation]
The following evaluations were performed on the endless belts manufactured in each example.

-Repeat bending durability (MIT test)-
Test method: JIS-P8115: 2001 compliant (MIT tester, sample width 15 mm, durability until breakage under a tensile load of 1 kg)
The endless belts obtained in each example are cut into strip-shaped samples with a width of 15 mm and a length of 200 mm in the circumferential direction, both ends are fixed, and a tensile tension of 1 kgf is applied. 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 times of bending resistance. Here, the above test was performed in an environment of normal temperature and humidity (temperature 22 ° C., humidity 55% RH).

-Surface resistivity (before image output)-
The surface resistivity (logΩ / □) of the endless belt obtained in each example was measured with an Advantest micro ammeter (UR probe / 100V / load 2kg / 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 belts obtained in each example were mounted on the image forming apparatus "DocuPrint C2250" manufactured by Fuji Xerox Co., Ltd. as intermediate transfer belts.
Then, in a low temperature and low humidity environment of 10 ° C./10% RH, the surface resistivity (logΩ / □) of the endless belt (intermediate transfer belt) after 50,000 images are output is the surface resistivity before image output. It was measured in the same way.

-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.) or the like.

-Surface roughness (after image output)-
The endless belts obtained in each example were mounted on the image forming apparatus "DocuPrint C2250" manufactured by Fuji Xerox Co., Ltd. as intermediate transfer belts.
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 50,000 image outputs is subject to the surface resistivity before the image output. Measured as well as rate

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

-Cleaning durability test during continuous use-
The endless belt obtained in each example is mounted as an intermediate transfer belt on the 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 is likely to occur due to peeling), after continuously outputting 50,000 images, image quality evaluation was performed on halftone (magenda 30%) images. Further, the surface resistivity (normal temperature and humidity (22 ° C. 55RH%), applied voltage 100V) of the endless belt (intermediate transfer belt) before and after the output of 50,000 images continuously 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: There is a decrease in image density (unacceptable level)

-Evaluation of the effect of changes in moisture absorption dimensions on image formation-
The endless belts obtained in each example were mounted on the image forming apparatus "DocuPrint C2250" manufactured by Fuji Xerox Co., Ltd. as intermediate transfer belts. After leaving it in an environment of 40 ° C. and 95% RH for 100 hours, a halftone (magenda 30%) image is continuously output on A5 paper under an environment of 10 ° C. and 10% RH, and 1,000 images are output. , The influence on the image quality due to the deformation of the intermediate transfer belt was confirmed. Here, the 10th 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: There is a decrease in image density (unacceptable level)

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

From the above results, the endless belt of this example was superior in bending durability to the endless belt of the comparative example.
Further, in the endless belt of this example, no significant decrease in the surface resistivity of the endless belt was observed before and after the image output, and the surface roughness of the belt did not occur. On the other hand, in the belt of the comparative example, a remarkable decrease in the surface resistivity of the belt was observed before and after the image output, and it can be seen that the surface of the belt was 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 had a remarkable elongation due to moisture absorption.
Further, in the cleaning durability test, the endless belt of this example did not show a decrease in image density, but the endless belt of the comparative example had image white streaks and images caused by poor cleaning due to the surface roughness of the endless belt. Halftone image density spots were observed due to a remarkable decrease in surface resistance before and after output.
Looking at the image evaluation results of the actual machine in which the change in moisture absorption dimensions affects the image formation, the belt of this example did not show any effect on the image, but the endless belt of the comparative example had poor image quality, so this implementation was carried out. It can be said that the belt of the example is excellent in image quality in image formation under moisture absorption.
Therefore, it can be seen that the endless belt obtained in this embodiment is excellent in dimensional stability due to moisture absorption, toner adhesion is reduced, and cleanability is good.

1Y, 1M, 1C, 1K Image forming unit 10 Primary transfer unit 11 Photoconductor 12 Charger 13 Laser exposure device 14 Developer 15 Intermediate transfer belt 16 Primary transfer roll 17 Photoreceptor cleaner 20 Secondary transfer unit 22 Secondary transfer roll 25 Back roll 26 Power supply roll 31 Drive roll 32 Support roll 33 Tensioning 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 inlet guide 60 Fixing device 100 Image forming device

Claims (12)

Unmodified imide resin (A) and
Siloxane-modified imide resin (B) and
The siloxane-treated conductive agent (C) and
A belt having an imide-based 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-based resin (B) is a dimethylsiloxane-modified imide-based resin. The invention according to any one of claims 1 to 4, wherein the content of the siloxane-modified imide-based resin (B) with respect to 100 parts by mass of the unmodified imide-based resin (A) is 5 parts by mass or more and 50 parts by mass or less. 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. The present invention according to any one of claims 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 or less . The described 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 the 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. The image forming apparatus including the endless belt according to claim 10.

Images