JP2018146684A - Belt for fixing, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt for fixing that has excellent wear resistance.SOLUTION: A belt for fixing comprises: a cylindrical base material 110A that forms an inner peripheral surface, and contains at least one resin selected from the group consisting of polyimide and polyamide-imide, and at least one solvent a selected from the solvent group A consisting of a urea-based solvent, an alkoxy group-containing amide-based solvent, and an ester group-containing amide-based solvent; and a surface layer 110C that is arranged on an outer periphery of the base material 110A.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fixing belt, a fixing device, and an image forming apparatus.

In an image forming apparatus such as a copying machine or a printer using an electrophotographic method, for example, a drum-shaped photoconductor is charged, and the photoconductor is exposed to light controlled based on image information to electrostatically form the photoconductor. A latent image is formed, and the electrostatic latent image is converted into a visible image (toner image) with toner. After the toner image is transferred from the photosensitive member to a recording medium such as paper, it is fixed on the recording medium by a fixing device. Thus, an image is formed.
The fixing device includes, for example, a pressure member that rotates and a belt member that rotates in contact with the pressure member, and presses the belt member from the inner peripheral surface toward the pressure member to apply pressure to the belt member. And a pressing member that forms a nip portion that allows a recording medium such as paper to pass between the pressure member and a fixing device that fixes the toner image on the recording medium by passing the recording medium through the nip portion. Are known.

  For example, Patent Document 1 includes a base made of a metal or a heat-resistant resin, and a rubbing layer formed on the inner peripheral surface of the base and rubbed against a rubbing member, and heated to a predetermined temperature. Thus, an endless heating belt that heats the recording material in contact with the outer peripheral surface thereof, wherein the rubbing layer has a first polyimide precursor and a loss elastic modulus more than that of the first polyimide precursor. A heating belt is disclosed which is a polyimide resin layer formed by mixing a large second polyimide precursor.

JP 2014-081470 A

As a fixing unit in an image forming apparatus, a fixing device including two rotating bodies that come into contact with each other to form a nip is used. A fixing belt is used as at least one of the two rotators, and a fixing belt that is driven to rotate while pressing the fixing belt in the nip direction on the inner peripheral surface side of the fixing belt; A sliding member that slides is provided.
In this fixing belt, wear powder may be generated due to friction caused by sliding with the sliding member, and wear resistance is required to suppress the generation of this wear powder.

  Therefore, an object of the present invention is to include at least one resin selected from the group consisting of polyimide and polyamideimide, and be disposed on the outer periphery of the cylindrical base material constituting the inner peripheral surface of the belt and the base material. An aspect of the present invention is to provide a fixing belt having excellent wear resistance as compared with the case where the substrate contains only N-methylpyrrolidone or N, N-diacetamide as a solvent.

The above problem is solved by the following means. That is,
The invention according to claim 1
At least one resin selected from the group consisting of polyimide and polyamideimide, and at least one solvent selected from solvent group A consisting of a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent a cylindrical base material that comprises a belt inner peripheral surface,
A surface layer disposed on the outer periphery of the substrate;
A fixing belt having:

The invention according to claim 2
The solvent a is tetramethylurea, tetraethylurea, 1,3-dimethyl-2-imidazolidinone, N, N-dimethylpropyleneurea, 3-methoxy-N, N-dimethylpropanamide, and 3-nbutoxy- The fixing belt according to claim 1, wherein the fixing belt is at least one solvent selected from a solvent group B consisting of N, N-dimethylpropanamide.

The invention according to claim 3
The fixing belt according to claim 1, wherein the solvent a is 1,3-dimethyl-2-imidazolidinone.

The invention according to claim 4
2. The inner peripheral surface of the substrate has a depth (indentation volume) of 0.06 μm ³ or less when a 115 ° triangular pyramid indenter is pushed with a load of 0.5 mN by a nanoindentation method. The fixing belt according to claim 3.

The invention according to claim 5
The fixing belt according to claim 1, wherein the base material further contains lubricating particles.

The invention according to claim 6
A fixing belt according to any one of claims 1 to 5,
A sliding member that contacts the inner peripheral surface of the fixing belt and slides with the fixing belt that is rotationally driven;
A fixing rotator that is disposed to face the sliding member with the fixing belt interposed therebetween and pressurizes an outer peripheral surface of the fixing belt;
Have
A fixing device for fixing a toner image on the recording medium by sandwiching a recording medium having an unfixed toner image formed on the surface between the fixing belt and the fixing rotating body.

The invention according to claim 7 provides:
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
A fixing unit comprising the fixing device according to claim 6 and fixing the toner image on the recording medium;
An image forming apparatus comprising:

According to the invention which concerns on Claim 1 or 2, The cylindrical base material which comprises the at least 1 sort (s) of resin selected from the group which consists of a polyimide and a polyamideimide, and comprises a belt inner peripheral surface, and the said base material In an embodiment having a surface layer disposed on the outer periphery, a fixing belt having excellent wear resistance is provided compared to the case where the substrate contains only N-methylpyrrolidone or N, N-diacetamide as a solvent. The
According to the invention of claim 3, there is provided a fixing belt that is further excellent in wear resistance as compared with a case where the base material contains only tetramethylurea or 3-methoxy-N, N-dimethylpropanamide as a solvent. Provided.
According to the invention of claim 4, the depth (indentation volume of the indenter) when the 115 ° triangular pyramid indenter is pushed with a load of 0.5 mN by the nanoindentation method on the inner peripheral surface of the substrate is 0. A fixing belt having excellent wear resistance as compared with the case of exceeding 0.06 μm ³ is provided.
According to the fifth aspect of the present invention, a fixing belt having excellent wear resistance is provided compared to the case where the base material does not contain lubricating particles.

  According to the invention which concerns on Claim 6 or 7, The cylindrical base material which comprises the at least 1 sort (s) of resin selected from the group which consists of a polyimide and a polyamideimide, and comprises a belt inner peripheral surface, and the said base material In an aspect provided with a fixing belt having a surface layer disposed on the outer periphery, the fixing device in which the generation of wear powder on the fixing belt is suppressed as compared with the case where the substrate contains only N-methylpyrrolidone as a solvent. Alternatively, an image forming apparatus is provided.

FIG. 3 is a schematic cross-sectional view illustrating an example of a fixing belt according to the present embodiment. 1 is a schematic configuration diagram illustrating an example of a fixing device according to an exemplary embodiment. It is a schematic block diagram which shows another example of the fixing device which concerns on this embodiment. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

  Hereinafter, an embodiment which is an example of the present invention will be described in detail.

[Fixing belt]
The fixing belt according to the present embodiment has a cylindrical base material constituting the inner peripheral surface of the belt and a surface layer disposed on the outer periphery of the base material.
The substrate is selected from at least one resin selected from the group consisting of polyimide and polyamideimide, and a solvent group A consisting of a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent. And at least one solvent a.

2. Description of the Related Art Conventionally, as a fixing unit in an image forming apparatus, a fixing unit having two rotating bodies that come into contact with each other to form a nip, and a heating unit that heats at least one of the rotating bodies. The device is used. In such a fixing device, the recording medium on which the unfixed toner image is formed is passed through the nip and heated and pressed to fix the toner image. In this fixing device, the fixing belt is used as a rotating body (so-called heat-fixing belt) provided with the heating unit, or a rotating body (so-called heating member) that does not have the heating unit and is responsible for pressurization toward the nip. Pressure fixing belt).
In the region where the nip of the fixing belt is formed, a sliding member that slides with the fixing belt that is driven to rotate is provided on the inner peripheral surface side, and the fixing belt is pressed against the nip by the sliding member. Is formed.
The fixing belt is generally configured to have a base material and a surface layer disposed on the outer periphery of the base material. For example, the fixing belt includes a base material and a release layer as the surface layer in this order. , A substrate, an elastic layer, and a release layer as a surface layer in this order are used. And the resin layer containing resin, such as a polyimide and a polyamideimide, is used for the base material which comprises an inner peripheral surface side.

Here, the base material of the fixing belt may be worn by friction with the sliding member to generate wear powder. Since the abrasion powder generated in this manner also leads to contamination in the fixing device, suppression thereof is required, that is, the base material is required to have resistance to abrasion due to sliding (wear resistance).
Conventionally, for the purpose of reducing the frictional force with the sliding member, it has been tried to use a base material containing lubricating particles such as fluororesin particles. However, in the base material containing the lubricating particles, while repeating sliding with the sliding member, the lubricating particles exposed on the base material surface are detached from the base material, and wear progresses around the hole after the removal, As a result, wear powder may still be generated.
In addition, for the purpose of reducing the frictional force with the sliding member, it has been tried to apply a lubricating oil to the inner peripheral surface of the base material. However, even when lubricating oil is used, it is not easy to completely suppress the generation of wear powder, and the viscosity of the lubricating oil may increase due to the generated wear powder. When the viscosity of the lubricating oil increases, the frictional resistance between the sliding member and the fixing belt changes (increases), so that wrinkles (paper wrinkles) may occur on the recording medium passing through the nip.
As described above, the base material of the fixing belt is required to suppress the generation of wear powder, regardless of which mode is used, and thus wear due to sliding with the sliding member is required. Resistance (wear resistance) is required.

In contrast, the fixing belt according to the present embodiment includes at least one resin selected from the group consisting of polyimide and polyamideimide, a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent. And a base material containing at least one solvent a selected from the solvent group A, whereby the wear resistance of the inner peripheral surface is excellent.
The reason is guessed as follows.

The base material of the fixing belt is, for example, at least one resin selected from the group consisting of polyimide and polyamideimide or a precursor thereof (for example, polyamic acid, polyamideimide precursor, polyamideimide resin which is a precursor of polyimide, etc.) ) Is applied by applying a composition dissolved in the solvent a to form a coating layer (coating film), and heating and curing the coating layer. In the process of heating and curing the composition, the solvent a evaporates, but a part of the solvent a remains as a residual solvent in the substrate. And in the base material with which the solvent a remained, it is thought that the polar group which the solvent a has produces an interaction between the polar groups which resin (polyimide or polyamideimide) has.
Here, the solvent a is a polar group as compared with solvents such as N-methylpyrrolidone (NMP) and N, N-diacetamide which have been widely used as solvents for dissolving polyimide, polyamideimide or a precursor thereof. It is a structure having many (for example, -O-, tertiary nitrogen atom (-N <)). Therefore, it is considered that the interaction between the solvent a and the resin is stronger than the interaction between N-methylpyrrolidone (NMP) and the resin. Due to this interaction, the substrate is considered to form a state in which the molecular chains of the solvent a and the molecular chains of the resin are densely packed (hereinafter referred to as “packing state”). It is done.
It is considered that the hardness of the substrate is increased by this packing state, and as a result, excellent wear resistance is obtained.

  As described above, according to the fixing belt of this embodiment, excellent wear resistance on the inner peripheral surface is realized.

The polar group of the solvent a corresponds to a urea group when the solvent a is a urea solvent. Further, when the solvent a is an alkoxy group-containing amide solvent, an alkoxy group and an amide group are applicable, and when the solvent a is an ester group-containing amide solvent, an ester group and an amide group are applicable.
The polar group of the polyimide precursor and the polyimide resin corresponds to an amide group or a carboxyl group, and the polar group of the polyamideimide precursor and the polyamideimide resin corresponds to an amide group or an imide group.

-Indenter indentation volume-
The fixing belt according to the present embodiment has a depth (indentation volume) of 0 when a 115 ° triangular pyramid indenter is pushed with a load of 0.5 mN by the nanoindentation method on the inner peripheral surface of the substrate. 0.06 μm is preferably ³ or less. Furthermore, 0.058 μm ³ or less is preferable.
When the indenter indentation volume is 0.06 μm ³ or less, the wear resistance on the inner peripheral surface is further improved.

On the other hand, the lower limit of the indentation volume, from the viewpoint of brittleness, preferably 0.04 .mu.m ³ or more, 0.05 .mu.m ³ or more is more preferable.

The indenter indentation volume on the inner peripheral surface of the fixing belt was measured using a nanoindenter (manufactured by Fisher Instruments, product name: PICODETOR HM500), test load: 0.5 mN, indenter type: 115 ° triangular pyramid indenter, Berkovich Measured with a diamond indenter.
Measurement conditions are set to a temperature of 23 ° C., a humidity of 65% RH, and a standard state defined by Japanese Industrial Standards.

-Young's modulus-
In the fixing belt according to the exemplary embodiment, the Young's modulus of the base material is preferably 8000 MPa or less, more preferably 7000 MPa or less, and further preferably 6000 MPa or less. When the Young's modulus of the base material is 8000 MPa or less, the flexibility is enhanced and the followability to bending when the fixing belt is rotationally driven can be obtained.
On the other hand, the lower limit of the Young's modulus of the base material is preferably 3000 MPa or more, more preferably 3500 MPa or more, and further preferably 4000 MPa or more from the viewpoint of suppressing elongation when tension is applied by the fixing device.

The Young's modulus of the base material of the fixing belt is obtained by a nanoindentation method. Using a nanoindenter (manufactured by Fischer Instruments, product name: PICODERTOR HM500), measure the indentation depth-load curve with an indenter type: 115 ° triangular pyramid indenter and Berkovich diamond indenter, and load the maximum indentation depth. The slope of the unloading curve when given at 500 nm and then unloading is determined as the Young's modulus.
Measurement conditions are set to a temperature of 23 ° C., a humidity of 65% RH, and a standard state defined by Japanese Industrial Standards.

  The indenter indentation volume on the inner peripheral surface of the base material and the Young's modulus of the base material are the selection of the resin constituting the base material, the selection of the solvent contained in the base material (remaining), the conditions during the base material formation (drying process) Or conditions such as a firing step).

  Next, the configuration of the fixing belt according to the present embodiment will be described in detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an example of a fixing belt according to the present embodiment.
As an aspect of the fixing belt according to the present embodiment, for example, as in the fixing belt 110 illustrated in FIG. 1, the base 110 </ b> A, the elastic layer 110 </ b> B provided on the base 110 </ b> A, and the elastic layer 110 </ b> B are provided. And a surface layer 110 </ b> C provided.
Although FIG. 1 shows an aspect having the elastic layer 110B, the fixing belt of the present embodiment does not include the elastic layer 110B, and includes a base material 110A and a surface layer 110C provided on the base material 110A. The aspect which has this may be sufficient.

  Alternatively, an adhesive layer may be interposed between the base material 110A and the elastic layer 110B, between the elastic layer 110B and the surface layer 110C, and between the base material 110A and the surface layer 110C.

  Here, components of the fixing belt according to the present embodiment will be described in detail. Note that the reference numerals are omitted.

(Base material)
The substrate is at least one selected from the group consisting of at least one resin selected from the group consisting of polyimide and polyamideimide, and a solvent group A consisting of a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent. Seed solvent a.
The base material is a polyimide precursor composition in which a polyimide precursor is dissolved in a solvent a, a polyamideimide precursor composition in which a polyamideimide precursor is dissolved in a solvent a, and a polyamide in which a polyamideimide resin is dissolved in a solvent a. It can form by using at least 1 type of an imide resin composition.
Hereinafter, the polyimide precursor composition, the polyamideimide precursor composition, and the polyamideimide resin composition will be described in order.

[Polyimide precursor composition]
Examples of the polyimide precursor composition include those containing a resin having a repeating unit represented by the following general formula (I) (hereinafter referred to as “specific polyimide precursor”) and a solvent a. Note that the polyimide precursor composition may include an additive described later.

-Polyimide precursor (polyamic acid)-
As a polyimide precursor, resin (specific polyimide precursor) which has a repeating unit represented by general formula (I) is mentioned.

(In general formula (I), A represents a tetravalent organic group, and B represents a divalent organic group.)

Here, in the general formula (I), the tetravalent organic group represented by A is a residue obtained by removing four carboxyl groups from a tetracarboxylic dianhydride as a raw material.
On the other hand, the divalent organic group represented by B is a residue obtained by removing two amino groups from a diamine compound as a raw material.

  That is, the specific polyimide precursor having a repeating unit represented by the general formula (I) is a polymer of tetracarboxylic dianhydride and a diamine compound.

  The tetracarboxylic dianhydride includes both aromatic and aliphatic compounds, but is preferably an aromatic compound. That is, in the general formula (I), the tetravalent organic group represented by A is preferably an aromatic organic group.

  Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and 3,3 ′, 4,4′-biphenyl. Sulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′- Biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4,4′-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3 ′, 4,4′-tetraphenylsilane tetracarboxylic dianhydride, 1 , 2,3,4-furantetracarboxylic dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride, 4,4′-bis (3,4-dicarboxyl) Noxi) diphenylsulfone dianhydride, 4,4′-bis (3,4-dicarboxyphenoxy) diphenylpropane dianhydride, 3,3 ′, 4,4′-perfluoroisopropylidenediphthalic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, bis (phthalic acid) phenylphosphine oxide dianhydride, p- Phenylene-bis (triphenylphthalic acid) dianhydride, m-phenylene-bis (triphenylphthalic acid) dianhydride, bis (triphenylphthalic acid) -4,4′-diphenyl ether dianhydride, bis (triphenyl) Phthalic acid) -4,4'-diphenylmethane dianhydride.

  Examples of the aliphatic tetracarboxylic dianhydride include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4. -Cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane 2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid Aliphatic or alicyclic tetracarboxylic dianhydrides such as acid dianhydrides, bicyclo [2,2,2] -oct-7-ene-2,3,5,6-tetracarboxylic dianhydrides; , 3,3a, 4,5,9b-hexahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5 9b-Hexahydro-5-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione, 1,3,3a, 4,5 Aliphatic tetracarboxylic acids having an aromatic ring such as 9b-hexahydro-8-methyl-5- (tetrahydro-2,5-dioxo-3-furanyl) -naphtho [1,2-c] furan-1,3-dione A dianhydride etc. are mentioned.

  Among these, the tetracarboxylic dianhydride is preferably an aromatic tetracarboxylic dianhydride, specifically, for example, pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyl. Tetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl ether tetracarboxylic dianhydride, 3,3 ′, 4 , 4′-benzophenonetetracarboxylic dianhydride is preferable, and pyromellitic dianhydride, 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4 ′ -Benzophenone tetracarboxylic dianhydride is good, especially 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride.

In addition, tetracarboxylic dianhydride may be used individually by 1 type, and may be used together in combination of 2 or more types.
When two or more kinds are used in combination, aromatic tetracarboxylic dianhydride or aliphatic tetracarboxylic dianhydride may be used in combination, and aromatic tetracarboxylic dianhydride and aliphatic tetracarboxylic You may combine with an acid dianhydride.

  On the other hand, a diamine compound is a diamine compound having two amino groups in the molecular structure. Examples of diamine compounds include aromatic and aliphatic compounds, but aromatic compounds are preferred. That is, in the general formula (I), the divalent organic group represented by B is preferably an aromatic organic group.

Examples of the diamine compound 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-diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4′-methylene-bis (2-chloroaniline), 2,2 ′, 5,5′-tetrachloro-4, 4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethoxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino- 2,2′-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) -biphenyl, 1,3′-bis (4-aminophenoxy) benzene, 9,9-bis 4-aminophenyl) fluorene, 4,4 ′-(p-phenyleneisopropylidene) bisaniline, 4,4 ′-(m-phenyleneisopropylidene) bisaniline, 2,2′-bis [4- (4-amino-2 -Trifluoromethylphenoxy) phenyl] hexafluoropropane, aromatic diamines such as 4,4′-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl; diaminotetraphenylthiophene, etc. An aromatic diamine having two amino groups bonded to an aromatic ring and a hetero atom other than the nitrogen atom of the amino group; 1,1-metaxylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylene Diamine, Octamethylenediamine, Nonamethylenediamine, 4,4-Diaminohept Diamine, 1,4-diaminocyclohexane, isophorone diamine, tetrahydrodicyclopentadiene cyclopentadienylide diamine, hexahydro-4,7-meth Noin mite range diamine, tricyclo [6,2,1,0 ^2.7] - Examples thereof include aliphatic diamines such as undecylenedimethyl diamine and 4,4′-methylene bis (cyclohexylamine), and alicyclic diamines.

  Among these, as the diamine compound, an aromatic diamine compound is preferable. Specifically, for example, p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, and 4,4′-diaminodiphenyl sulfone are preferable, and 4,4′-diaminodiphenyl ether and p-phenylenediamine are particularly preferable.

  In addition, a diamine compound may be used individually by 1 type, and may be used together in combination of 2 or more types. Moreover, when using together and using 2 or more types, you may use together an aromatic diamine compound or an aliphatic diamine compound, respectively, or may combine an aromatic diamine compound and an aliphatic diamine compound.

The specific polyimide precursor may be a resin partially imidized.
Specifically, the specific polyimide precursor includes a resin having a repeating unit represented by General Formula (I-1), General Formula (I-2), and General Formula (I-3).

In General Formula (I-1), General Formula (I-2), and General Formula (I-3), A represents a tetravalent organic group, and B represents a divalent organic group. In addition, A and B are synonymous with A and B in general formula (I).
l represents an integer of 1 or more, and m and n each independently represents 0 or an integer of 1 or more.

The number average molecular weight of the specific polyimide precursor is preferably from 5,000 to 100,000, more preferably from 7,000 to 50,000, and still more preferably from 10,000 to 30,000.
When the number average molecular weight of the specific polyimide precursor is within the above range, the solubility of the polyimide precursor in the composition and the mechanical properties of the film after film formation are improved.
In addition, the specific polyimide precursor of the target number average molecular weight is obtained by adjusting the molar equivalent ratio of a tetracarboxylic dianhydride and a diamine compound.

The number average molecular weight of the specific polyimide precursor is measured by a gel permeation chromatography (GPC) method under the following measurement conditions.
Column: Tosoh TSKgel α-M (7.8 mm ID × 30 cm)
Eluent: DMF (dimethylformamide) / 30 mM LiBr / 60 mM phosphoric acidFlow rate: 0.6 mL / min
・ Injection volume: 60 μL
・ Detector: RI (differential refractive index detector)

  The content (concentration) of the specific polyimide precursor may be 0.1% by mass or more and 40% by mass or less, preferably 0.5% by mass or more and 25% by mass with respect to the total amount of the polyimide precursor composition. Hereinafter, it is more preferably 1% by mass or more and 20% by mass or less.

[Polyamideimide precursor composition and polyamideimide resin composition]
The polyamideimide precursor composition includes a polyamideimide precursor and a solvent a. The polyamideimide resin composition contains a polyamideimide resin and a solvent a. Note that the polyamideimide precursor composition and the polyamideimide resin composition may contain an additive to be described later.

-Polyamideimide precursor (polyamideimide resin)-
Examples of the polyamideimide precursor include polyamide-polyamic acid which is a condensate of tricarboxylic acid and diamine compound. When the polyamide-polyamic acid as the polyamide-imide precursor is subjected to an imidization reaction (dehydration ring-closing reaction), a polyamide-imide resin is obtained.
Specifically, as the polyamideimide precursor, for example, (1) a method in which an equimolar amount of a tricarboxylic acid anhydride and a diamine is polycondensed in a solvent in the presence of a dehydration catalyst at a high temperature; Polyamide-obtained by polycondensation and imidization reaction of equimolar amounts of chloride and diamine in solvent at low temperature, (3) polycondensation of tricarboxylic acid anhydride and diisocyanate in solvent at high temperature, etc. A polyamic acid is mentioned. And when the polyamide-polyamic acid which is the obtained polyamide-imide precursor is imidized (dehydration ring-closing reaction), a polyamide-imide resin is obtained.

  Examples of the tricarboxylic acid anhydride include trimellitic acid anhydride or trimellitic acid monochloride.

  As a diamine compound, the thing similar to what was illustrated as a diamine compound used for the synthesis | combination of a polyamic acid in description of the above-mentioned polyimide precursor is mentioned.

Moreover, the aromatic diamine compound shown below is also mentioned as a diamine compound.
As aromatic diamine compounds, 3,3′-diaminobenzophenone, p-phenylenediamine, 4,4′-diaminodiphenyl, 4,4′-diaminodiphenylamide, 4,4′-diaminodiphenylmethane, 4,4 '-Diaminodiphenyl ether, bis [4- {3- (4-aminophenoxy) benzoyl} phenyl] ether, 4,4'-bis (3-aminophenoxy) biphenyl, and bis [4- (3-aminophenoxy) phenyl] sulfone 2 , 2′-bis [4- (3-aminophenoxy) phenyl] propane (also referred to as “aromatic diamine compound group (DA)”).

  Of these, aromatic diamine compounds are preferred, and the aromatic diamine compound group (DA) listed above is more preferred.

  Examples of the diisocyanate compound include those in which two amino groups are substituted with isocyanate groups in the examples of diamine compounds used for the synthesis of polyamic acid in the description of the polyimide precursor described above.

Moreover, as a diisocyanate compound, the diisocyanate compound shown below is also mentioned.
Examples of the diisocyanate compound include 3,3′-dimethylbiphenyl-4,4′-diisocyanate, 2,2′-dimethylbiphenyl-4,4′-diisocyanate, biphenyl-4,4′-diisocyanate, and 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, and 2,2′-dimethoxybiphenyl-4,4′-diisocyanate (these are also referred to as “diisocyanate compound group (DI)”).

  Examples of the diisocyanate compound include those obtained by stabilizing an isocyanato group with a blocking agent. The blocking agent includes alcohol, phenol, oxime, etc., but there is no particular limitation.

  Among these, the diisocyanate compound group (DI) listed above is more preferable.

[Solvent a]
The solvent a contained in the substrate is at least one selected from the solvent group A consisting of a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent.
Hereinafter, a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent will be described in order.

-Urea solvent-
The urea solvent is a solvent having a urea group (N—C (═O) —N). Specifically, the urea solvent is preferably a solvent having a “* —N (Ra1) —C (═O) —N (Ra2) — *” structure. Here, Ra1 and Ra2 each independently represent a hydrogen atom, an alkyl group, a phenyl group, or a phenylalkyl group. Both ends * of two N atoms indicate a bonding site with another atomic group of the structure. A urea solvent is a solvent having a ring structure in which both ends * of two N atoms are linked via a linking group consisting of, for example, alkylene, -O-, -C (= O)-, or a combination thereof. It may be.

The alkyl group representing Ra1 and Ra2 may be any of chain, branched, and cyclic, and may have a substituent. Specific examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms (preferably 1 to 4 carbon atoms) (for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group). Etc.).
Examples of the substituent of the alkyl group include an alkoxy group (preferably an alkoxy group having 1 to 4 carbon atoms), a hydroxyl group, a ketone group, an ester group, an alkylcarbonyloxy group, and the like. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, and a t-butoxy group.
Specific examples of the ketone group include a methylcarbonyl group (acetyl group), an ethylcarbonyl group, and an n-propylcarbonyl group. Specific examples of the ester group include methoxycarbonyl group (—COOMe), ethoxycarbonyl group, n-propoxycarbonyl group, acetoxy group (—OC (═O) Me) and the like. Specific examples of the alkylcarbonyloxy group include a methylcarbonyloxy group (acetyloxy group), an ethylcarbonyloxy group, and an n-propylcarbonyloxy group.

  The phenyl skeleton of the phenyl group and phenylalkyl group representing Ra1 and Ra2 may have a substituent. Examples of the substituent of the phenyl skeleton include the same substituents as the alkyl group.

  In addition, when the urea solvent has a ring structure in which both ends * of the two N atoms are connected, the number of ring members is preferably 5 or 6.

  Examples of urea solvents include 1,3-dimethylurea, 1,3-diethylurea, 1,3-diphenylurea, 1,3-dicyclohexylurea, tetramethylurea, tetraethylurea, and 2-imidazolidinone. Propylene urea, 1,3-dimethyl-2-imidazolidinone, N, N′-dimethylpropylene urea, and the like.

-Alkoxy group-containing amide solvent, ester group-containing amide solvent-
The alkoxy group-containing amide solvent is a solvent having an alkoxy group and an amide group. On the other hand, the ester group-containing amide solvent is a solvent having an ester group and an amide group. Examples of the alkoxy group and ester group include the same groups as the alkoxy group and ester group exemplified as the “substituent of the alkyl group for Ra1 and Ra2” in the description of the urea solvent. The alkoxy group-containing amide solvent may have an ester group, and the ester group-containing amide solvent may have an alkoxy group.

  Hereinafter, both the alkoxy group-containing amide solvent and the ester group-containing amide solvent will be referred to as “alkoxy group or ester group-containing amide solvent”.

  The alkoxy group or ester group-containing amide solvent is not particularly limited, and specifically, an amide solvent represented by the following general formula (Am1), an amide solvent represented by the following general formula (Am2), and the like are preferable. It is mentioned in.

In General Formula (Am1), Rb ¹ , Rb ² , Rb ³ , Rb ⁴ , Rb ⁵ , and Rb ⁶ each independently represent a hydrogen atom or an alkyl group. Rb ⁷ represents an alkoxy group or an ester group.
Alkyl group represented by Rb ¹ ~Rb ⁶ have the same meanings as described in the description of the urea-based solvent "Ra1, and alkyl group represented by Ra2."
Alkoxy and ester groups show a rb ^7, in the description of urea solvent, exemplified alkoxy groups as "Ra1, and substituent of the alkyl group represented by Ra2" is synonymous with an ester group.

  Specific examples of the amide solvent represented by the general formula (Am1) are shown below, but are not limited thereto.

  In specific examples of the amide solvent represented by the general formula (Am1), Me = methyl group, Et = ethyl group, nPr = n-propyl group, nBu = n-butyl group.

In General Formula (Am2), Rc ¹ , Rc ² , Rc ³ , Rc ⁴ , Rc ⁵ , Rc ⁶ , Rc ⁷ , and Rc ⁸ each independently represent a hydrogen atom or an alkyl group. Rc ⁹ represents an alkoxy group or an ester group.
Alkyl group represented by rc ¹ to Rc ⁸ is synonymous with that described in the description of the urea-based solvent "Ra1, and alkyl group represented by Ra2."
Alkoxy and ester groups show a rc ^9, in explanation of the urea based solvent, exemplified alkoxy groups as "Ra1, and substituent of the alkyl group represented by Ra2" is synonymous with an ester group.

  Specific examples of the amide solvent represented by the general formula (Am2) are shown below, but are not limited thereto.

  In specific examples of the amide solvent represented by the general formula (Am2), Me = methyl group, Et = ethyl group, and nPr = n-propyl group.

-Content of solvent a-
The content of the solvent a is preferably 0.005% by mass to 3% by mass, more preferably 0.05% by mass to 2% by mass with respect to the entire base material.
When the content of the solvent a is 3% by mass or less, a state in which molecular chains are densely packed in the base material (packing state) is easily formed, and excellent wear resistance is easily obtained.
When the content of the solvent a is 0.005% by mass or more, the temperature (drying temperature, firing temperature) and time (drying time, firing) in the drying step and firing step when the base material of the fixing belt is produced. Time) is not excessive and cracking of the substrate is suppressed.
The content of at least one solvent a selected from the solvent group A represents the total amount of the solvent a and is the content relative to the entire substrate.

  As a method for controlling the content of the solvent a within the above range, for example, a method for adjusting drying conditions (temperature, time) for drying a coating film in a method for producing a base material for a fixing belt described later; Method of adjusting the baking conditions (temperature, time) when the dried film is further heated (baking step) after drying the film; Method of adjusting the blowing speed when blowing the coating film; A method for adjusting the rotational speed of a mold when forming a coating film; a method for adjusting the temperature and thickness of the mold; a polyimide precursor composition used for forming a substrate, a polyamideimide precursor composition, and Examples include a method of adjusting the content of all solvents in the polyamideimide resin composition and the content of the solvent a occupying therein; other methods of adjusting by vacuum drying; and the like.

The content of the solvent a contained in the substrate (content of residual solvent) is measured using a gas chromatograph mass spectrometer (GC-MS).
Specifically, a gas chromatograph mass in which 0.40 mg of a measurement sample is accurately weighed from the base material of the fixing belt to be measured, and a drop-type thermal decomposition apparatus (manufactured by Frontier Lab: PY-2020D) is installed. Measurement is performed under the following conditions using an analyzer (manufactured by Shimadzu Corporation: GCMS QP-2010).
Thermal decomposition temperature: 400 ° C
Gas chromatography introduction temperature: 280 ° C
Inject method: Split ratio 1:50
Column: Ultra ALLOY-5 0.25 μm, 0.25 μm ID, 30 m manufactured by Frontier Lab
Gas chromatographic temperature program: 40 ° C. => 20 ° C./min=>280° C.—10 min retention Mass range: EI, m / z = 29-600

-Boiling point of solvent a-
The boiling point of the solvent a (each solvent in the solvent group A) is, for example, preferably from 100 ° C. to 350 ° C., more preferably from 120 ° C. to 300 ° C., and still more preferably from 150 ° C. to 250 ° C.
When the boiling point of the solvent a is 100 ° C. or higher, the solvent a contained in the substrate is suppressed from being reduced during use of the fixing belt.
On the other hand, when the boiling point of the solvent a is 350 ° C. or lower (especially 250 ° C. or lower), the content of the solvent a contained in the base material after the fixing belt is produced is controlled within the above range with respect to the whole base material. It becomes easy to be done.

The base material may contain an organic solvent other than the solvent a as long as the effects of the present embodiment are not impaired. Examples of the organic solvent other than the solvent a include known solvents.
When the base material contains an organic solvent other than the solvent a, the content of the solvent a occupies the organic solvent other than the solvent a. More preferably, it is preferably 60% by mass or more, and more preferably 70% by mass or more.

〔Additive〕
-Lubricating particles The base material may contain lubricating particles for the purpose of reducing the frictional force with the sliding member. Examples of the lubricating particles include fluorine-based resin particles (resin particles having fluorine atoms in the structural units constituting the resin particles).
Examples of the material of the fluororesin particles contained in the base material include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA), tetrafluoroethylene- Perfluoroethyl vinyl ether copolymer (EFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polyethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychloro Examples thereof include ethylene trifluoride (PCTFE) and vinyl fluoride (PVF). Among these, polytetrafluoroethylene (PTFE) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) is preferable.
These lubricating particles may be used alone or in combination of two or more.

The particle diameter (average primary particle diameter) of the lubricating particles is preferably 0.05 μm or more and 1.0 μm or less, and more preferably 0.1 μm or more and 0.7 μm or less.
In addition, the average primary particle diameter of the lubricating particles is 100 from a photomicrograph of a microscope capable of observing a substance of nm order to μm order such as TEM (transmission electron microscope) or SEM (scanning electron microscope). The particle diameter (primary particle diameter) of the individual lubricating particles is measured, and the average value is calculated.

The content of the lubricating particles is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, and further preferably 0.2% by mass with respect to the entire substrate. The content is 2% by mass or less.
When the content of the lubricating particles is 0.01% by mass or more, it becomes easier to reduce the frictional force with the sliding member. When the content of the lubricating particles is 5% by mass or less, the strength of the base material is easily maintained.

-Other additives The base material may contain various fillers for the purpose of imparting various functions such as mechanical strength. Also, it may contain a catalyst for promoting imidization reaction, a leveling agent for improving film forming quality, an antioxidant for preventing thermal deterioration of the fixing belt, a surfactant for improving fluidity, etc. Good.
Further, a conductive agent (carbon black or the like) may be added and dispersed in the base material of the fixing belt to control the volume resistivity.
What is necessary is just to select content of another additive according to the characteristic made into the said base material. In addition, what is necessary is just to include another additive in the precursor composition for obtaining the said base material.

  The thickness of the substrate is not particularly limited. For example, from the viewpoint of ensuring mechanical strength and flexibility, it is preferably 20 μm or more and 200 μm or less, more preferably 30 μm or more and 150 μm or less, and even more preferably 40 μm. It is 130 μm or less.

(Elastic layer)
In this embodiment, the fixing belt may have an elastic layer.
The elastic layer is a layer provided from the viewpoint of imparting elasticity to the pressure applied from the outer peripheral side to the fixing belt. For example, when used as a heat fixing belt in an image forming apparatus, the elastic layer The layer plays a role of closely contacting the surface of the heat-fixing belt with the toner image following the unevenness of the toner image.

  Examples of the material of the elastic layer include fluororesin, silicone resin, silicone rubber, fluororubber, and fluorosilicone rubber. From the viewpoint of heat resistance, thermal conductivity, insulation, etc., for example, silicone rubber is preferable.

  A filler may be further blended in the elastic layer from the viewpoint of reinforcement, heat resistance, heat transfer, and the like. As the filler, known ones are used, and examples thereof include fumed silica, crystalline silica, iron oxide, alumina, silicon metal, carbide (for example, carbon black, carbon fiber, carbon nanotube, etc.).

  For example, the thickness of the elastic layer is preferably in the range of 50 μm to 1000 μm, and more preferably in the range of 100 μm to 600 μm.

(Surface layer)
In this embodiment, a surface layer is provided on the outer peripheral surface of the fixing belt.
The surface layer is required to have heat resistance and releasability, for example. From this viewpoint, it is preferable to use a heat-resistant release material as the material constituting the surface layer, and specific examples include fluororubber, fluororesin, and silicone resin.
Among these, a fluororesin is preferable as the heat-resistant release material.
Specific examples of such a fluororesin include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polyethylene. -Tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), vinyl fluoride (PVF) and the like.
In addition to the fluororesin, examples of the material for the surface layer include silicone resin, silicone rubber, fluororubber, and fluorinated polyimide.

  A surface treatment may be applied to the inner peripheral surface of the surface layer. The surface treatment may be a wet treatment or a dry treatment, and examples thereof include liquid ammonia treatment, excimer laser treatment, and plasma treatment.

  The thickness of the surface layer is preferably in the range of 20 μm to 100 μm, for example.

(Fixing belt manufacturing method)
First, a method for forming a base material in a fixing belt will be described.
The base material is formed by preparing at least one of a polyimide precursor composition, a polyamideimide precursor composition, and a polyamideimide resin composition (preparation process of a precursor composition) and the precursor composition. A process of forming a coating film by coating on a cylindrical mold (coating film forming process), a process of drying the coating film formed on the mold (drying process), and a dried coating film (drying) And a step of further heating the film) to form a resin film (resin film forming step (firing step)).
Below, the case where a base material contains a polyimide resin is demonstrated. In addition, also when a base material contains a polyamidoimide resin, it can form according to the following methods.

-Preparation process of precursor composition-
In the step of preparing the precursor composition, a polyimide precursor composition for forming a substrate is prepared. Lubricant particles, a conductive agent such as carbon black, other additives, and the like may be dispersed in the precursor composition. As a method for dispersing these in the precursor composition, for example, a media mill for pulverizing using the impact force of media such as ceramic beads and balls, a high shear force passing through an orifice at a high pressure and colliding with the media. Commonly used dispersion methods such as wet jet mills and homogenizers that utilize the impact force of the time are included.

-Film formation process-
Next, the precursor composition is applied to the outer surface of a cylindrical mold to form a coating film. As the cylindrical mold, for example, a metal mold is suitably used. Instead of metal, other materials such as resin, glass, and ceramic may be used. Further, a glass coat, a ceramic coat or the like may be provided on the surface of the mold, and a release agent such as silicone or fluorine may be applied.

  Here, in order to apply the precursor composition with high accuracy, a step of defoaming the precursor composition is preferably performed before the application. By defoaming the precursor composition, foaming at the time of coating and occurrence of defects in the coating film are suppressed. Examples of the method for defoaming the precursor composition include a method for reducing the pressure, a method for centrifuging, and the like. However, defoaming under a reduced pressure is simple and suitable for high defoaming ability.

As a method of applying the precursor composition to the surface of the cylindrical mold, for example, the cylindrical composition is moved by moving the rotating cylindrical mold in the direction of the rotation axis while discharging the precursor composition from the nozzle. A method in which a precursor composition is spirally coated on the outer peripheral surface of a metal mold (spiral coating method), and a blade is pressed against the precursor composition discharged on the mold surface during the spiral coating method Examples thereof include a method of moving in the direction of the rotation axis (blade coating method) and a dip coating method in which a cylindrical mold is dipped in the precursor composition and pulled up.
In addition, a coating film may be formed on the inner surface side of the mold, and an application method in that case includes a method of pouring the precursor composition in the axial direction on the inner peripheral surface of the cylindrical mold.

-Drying process-
Subsequently, the formed coating film is dried to form a dry film.
The coating film is dried, for example, by volatilizing the solvent by heating while rotating the mold. It is preferable to dry the coating film until the precursor composition does not sag even without rotating the mold.
As drying conditions, for example, a drying time in the range of 50 ° C. or higher and 180 ° C. or lower (preferably 60 ° C. or higher and 150 ° C. or lower) in the range of 15 minutes or longer and 60 minutes or shorter (preferably 20 minutes or longer and 40 minutes or shorter); More preferably.
The solvent content in the dry film is preferably 60% by mass or less (more preferably 50% by mass or less, and still more preferably 40% by mass or less) with respect to the total mass of the dry film.

-Resin film formation process (firing process)-
Subsequently, a step of heating and baking the formed dry film at a higher temperature (in this embodiment, imidization treatment) may be provided. By heating at a higher temperature, the solvent of the dried film is further volatilized to form a resin film containing a polyimide resin.
The heating conditions for the imidization treatment are, for example, 150 ° C. or higher and 400 ° C. or lower (preferably 200 ° C. or higher and 350 ° C. or lower). The In the heating reaction, before reaching the final temperature of heating, it is preferable to heat by gradually increasing the temperature stepwise or at a constant rate. The imidation temperature varies depending on, for example, the types of tetracarboxylic dianhydride and diamine used as raw materials, and is preferably set to a temperature at which imidization is completed from the viewpoint of mechanical characteristics and electrical characteristics.
A base material is formed through the above steps.

-Surface layer forming step, or elastic layer and surface layer forming step-
By forming an elastic layer or a surface layer on the outer peripheral surface of the substrate thus obtained, the fixing belt according to this embodiment can be obtained.

A known method may be applied to form the elastic layer and the surface layer. For example, the elastic layer and the surface layer may be sequentially formed on the substrate by a coating method.
When the elastic layer and the surface layer are formed on the base material by a coating method, pre-treatment with an appropriate primer material is performed on the surface of the base material or the elastic layer surface before applying these layers. A layer may be formed.
Moreover, when forming an elastic layer and a surface layer by the apply | coating method, an elastic layer and a surface layer are formed through the process of heat-processing the coating film formed by application | coating. The heat treatment of the coating film may be performed in an inert gas (nitrogen gas, argon gas, etc.) atmosphere.
Further, these heat treatments may be a process that also serves as firing in the above-mentioned “resin coating film forming process”. That is, after passing through the drying step in the substrate forming method, the surface layer or the elastic layer and the surface layer are applied to form a coating film, and then heated (the surface layer or the elastic layer and the surface layer The fixing belt may be manufactured through a heat treatment and a resin film forming step (step of baking and forming a base material).

(Application of fixing belt)
The fixing belt according to the present embodiment is applied to, for example, a heat fixing belt and a pressure fixing belt in a fixing device for an image forming apparatus. Examples of the heat source in the heat fixing belt include a method of heating from an external heat source and an electromagnetic induction method.

[Fixing device]
Next, the fixing device according to this embodiment will be described.
The fixing device according to this embodiment includes the fixing belt according to the above-described embodiment, a sliding member that contacts the inner peripheral surface of the fixing belt and slides on the fixing belt that is rotationally driven. A fixing rotator that is disposed to face the sliding member with the fixing belt interposed therebetween and pressurizes an outer peripheral surface of the fixing belt. Then, the recording medium on which the unfixed toner image is formed is sandwiched between the fixing belt and the fixing rotator to fix the toner image on the recording medium.

Hereinafter, as an aspect of the fixing device, an aspect (first aspect) including a heating roll and a pressure fixing belt, and an aspect (second aspect) including a heat fixing belt and a pressure roll will be described. .
The fixing device is not limited to the first and second modes, and may be a fixing device including a heat fixing belt and a pressure fixing belt. In this case, the fixing belt according to the present embodiment is a heat fixing belt. It can be applied to both a belt and a pressure fixing belt.
Further, the fixing device is not limited to the first and second modes, and may be an electromagnetic induction heating type fixing device.

First Embodiment of Fixing Device A fixing device according to the first embodiment will be described. FIG. 2 is a schematic diagram illustrating an example of the fixing device according to the first aspect.

As shown in FIG. 2, the fixing device 60 according to the first aspect includes, for example, a heating roll 61 (an example of a fixing rotating body) that is rotationally driven, a pressure fixing belt 62 (an example of a fixing belt), A pressing pad 64 (pressing member) that presses the heating roll 61 via the pressure fixing belt 62 is provided.
For example, the pressure pad 64 may be configured so that the pressure fixing belt 62 and the heating roll 61 are relatively pressurized. Accordingly, the pressure fixing belt 62 side may be pressed by the heating roll 61, and the heating roll 61 side may be pressed by the pressure fixing belt 62.

  Inside the heating roll 61, a halogen lamp 66 (an example of a heating means) is disposed. The heating means is not limited to the halogen lamp, and other heat generating members that generate heat may be used.

  On the other hand, for example, a temperature sensitive element 69 is disposed on the surface of the heating roll 61 in contact therewith. The lighting of the halogen lamp 66 is controlled based on the temperature measurement value by the temperature sensing element 69, and the surface temperature of the heating roll 61 is maintained at a target set temperature (for example, 150 ° C.).

  The pressure fixing belt 62 is rotatably supported by, for example, a pressing pad 64 and a belt traveling guide 63 disposed inside. And it is arranged to be pressed against the heating roll 61 by the pressing pad 64 in the sandwiching area (nip) N.

For example, the pressure pad 64 is arranged inside the pressure fixing belt 62 in a state of being pressed against the heating roll 61 via the pressure fixing belt 62, and forms a sandwiching region N with the heating roll 61. doing.
In the pressing pad 64, for example, a front clamping member 64a for securing a wide clamping area N is disposed on the entrance side of the clamping area (nip) N, and a peeling clamp for imparting distortion to the heating roll 61 is provided. The insertion member 64b is arranged on the exit side of the sandwiching region N.

In order to reduce the sliding resistance (friction) between the inner peripheral surface of the pressure fixing belt 62 and the pressing pad 64, for example, the surface of the front sandwiching member 64a and the peeling sandwiching member 64b in contact with the pressure fixing belt 62 is used. A sheet-like low friction member 68 (an example of a sliding member) is provided. The pressing pad 64 and the low friction member 68 are held by a metal holding member 65.
The low friction member 68 is provided, for example, such that its sliding surface is in contact with the inner peripheral surface of the pressure fixing belt 62, and holds the lubricating oil existing between the pressure fixing belt 62, Involved in supply.
Here, as the lubricating oil, for example, silicone oil (for example, unmodified silicone oil, amino-modified silicone oil, dimethyl silicone oil, methylphenyl silicone oil, carboxy-modified silicone oil, silanol-modified silicone oil, sulfonic acid-modified silicone oil, etc.) , Fluorine oil (for example, perfluoropolyether oil, modified perfluoropolyether oil, etc.), synthetic lubricating oil grease (for example, silicone grease, fluorine grease, etc.) mixed with solid substance and liquid, and organic metal in these oils Examples thereof include oil added with salt, hindered amine and the like.

In the fixing device shown in FIG. 2, the low friction member 68 constitutes a sliding member that slides on the inner peripheral surface of the pressure fixing belt 62, but in the case where the low friction member 68 is not provided, A sliding member 64 slides on the inner peripheral surface of the pressure fixing belt 62.
About the material of the press pad 64 and the material of the low friction member 68, the material similar to the material of the press pad 164 in the 2nd aspect mentioned later and the low friction member is mentioned.

  For example, a belt traveling guide 63 is attached to the holding member 65 so that the pressure fixing belt 62 rotates.

  The heating roll 61 is rotated in the direction of arrow S by, for example, a drive motor (not shown), and the pressure fixing belt 62 is rotated in the direction of arrow R opposite to the rotation direction of the heating roll 61 following this rotation. That is, for example, while the heating roll 61 rotates in the clockwise direction in FIG. 2, the pressure fixing belt 62 rotates in the counterclockwise direction.

  The sheet K (an example of a recording medium) having an unfixed toner image is guided by, for example, a fixing inlet guide 56 and conveyed to a sandwiching area (nip) N. When the sheet K passes through the sandwiching area (nip) N, the toner image on the sheet K is fixed by pressure and heat acting on the sandwiching area (nip) N.

  In the fixing device 60 according to the first aspect, for example, a concave sandwiched front sandwiching member 64a that follows the outer peripheral surface of the heating roll 61 has a wider sandwiched region N as compared to a configuration without the front sandwiching member 64a. Secured.

  Further, in the fixing device 60 according to the first aspect, for example, the peeling nipping member 64b is disposed so as to protrude from the outer peripheral surface of the heating roll 61, so that the heating roll 61 is distorted in the exit area of the nipping area N. Is configured to be locally large.

  If the peeling and clamping member 64b is arranged in this way, for example, the sheet K after being fixed passes through the locally formed distortion when passing through the peeling and clamping area. Is easy to peel from the heating roll 61.

  As an auxiliary means for peeling, for example, a peeling member 70 is disposed on the downstream side of the sandwiching area N of the heating roll 61. For example, the peeling member 70 is held by the holding member 72 in a state in which the peeling claw 71 is close to the heating roll 61 in a direction (counter direction) opposite to the rotation direction of the heating roll 61.

Second Embodiment of Fixing Device Next, the fixing device according to the second embodiment will be described.
FIG. 3 is a schematic diagram illustrating an example of a fixing device according to the second aspect.

  As shown in FIG. 3, the fixing device 160 according to the second aspect includes a pressure roll 161 (an example of a fixing rotating body) that is rotationally driven, and a heat fixing belt 162 (an example of a fixing belt). . Further, the pressure pad 161 is pressed through the heat fixing belt 162 to form a nip portion through which the paper K (an example of a recording medium) passes between the heat fixing belt 162 and the pressure roll 161. An example of the sliding member is provided inside the heat fixing belt 162. Further, a belt traveling guide 163 and a belt traveling auxiliary guide 166 are provided inside the heat fixing belt 162, and the heat fixing belt 162 is connected to the belt traveling guide 163, the belt traveling assist guide 166, and the pressure pad 164 (sliding). It is configured to move around along the outer peripheral surface of the member. The belt traveling guide 163 and the pressing pad 164 are attached to the holder 165 inside the heat fixing belt 162. A heating element 169 is provided between the belt running guide 163 and the heat fixing belt 162 as a heat source for the heat fixing belt 162.

  In the fixing device 160, the pressure roll 161 is rotated in the direction of arrow S by a drive motor (not shown), for example, and the heat fixing belt 162 is driven by this rotation, and the arrow R opposite to the direction of rotation of the pressure roll 161. Rotate in the direction. That is, for example, while the pressure roll 161 rotates counterclockwise in FIG. 3, the heat fixing belt 162 rotates clockwise.

  Here, each member will be described in more detail.

-Pressure roll The pressure roll 161 is, for example, a solid metal core (cylindrical core metal) 161A, a heat resistant elastic body layer 161B disposed around the core 161A, and a heat resistant elastic body layer 161B. It is a cylindrical roll provided with the surface layer 161C arrange | positioned around. The pressure roll 161 is not limited in its shape, structure, size and the like, and a known pressure roll is used according to the purpose.

  Both ends of the core 161A are rotatably supported by a bearing member (not shown), for example, and predetermined with respect to the heat fixing belt 162 by a biasing member such as a coil spring disposed at both ends of the core 161A. Pressure contact.

  Examples of the material of the core 161A of the pressure roll 161 include a metal or alloy having high thermal conductivity such as iron, aluminum (for example, A-5052 material), SUS, copper, ceramics, fiber reinforced metal (FRM), and the like. It is done.

  The material of the heat-resistant elastic body layer 161B of the pressure roll 161 is, for example, rubber, elastomer or foam whose hardness (JIS-A: hardness measured by a JIS-KA type testing machine) is 15 ° or more and 160 ° or less. Examples of the resin include silicone rubber, fluorine rubber, and liquid silicone rubber filled with hollow glass beads. The thickness of the heat resistant elastic layer is not particularly limited, but is preferably in the range of 2 mm to 20 mm, and more preferably in the range of 3 mm to 10 mm.

  The material of the surface layer 161C of the pressure roll 161 may be a resin or the like. Examples of the resin for forming the surface layer 161C include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-, from the viewpoints of heat resistance and releasability. Fluororesin such as hexafluoropropylene copolymer (FEP), silicone resin, silicone rubber, fluororubber, and fluorinated polyimide.

The surface layer 161C may have conductivity, and may be a layer having a volume resistivity of 1 × 10 ⁴ Ωcm or less. Examples of the material for forming the conductive surface layer include resins containing conductive particles such as carbon black, graphite, and metal powder. The thickness of the surface layer is not particularly limited, but for example, a range of 10 μm to 200 μm is preferable, and a range of 20 μm to 100 μm is more preferable.

-Pressing pad The pressing pad 164 is supported by a holder 165 made of metal or the like inside the heat-fixing belt 162, for example. The pressing pad 164 is disposed so as to face the pressure roll 161 with the heat fixing belt 162 interposed therebetween, and presses the heat fixing belt 162 from the inner peripheral surface of the heat fixing belt 162 to the pressure roll 161 to thereby heat the heat fixing belt 162. And a pressure roll 161, a nip portion through which the paper passes is formed.
In the fixing device shown in FIG. 3, the pressing pad 164 constitutes a sliding member that slides on the inner peripheral surface of the heat fixing belt 162.

  It is sufficient that the heat fixing belt 162 and the pressure roll 161 are relatively pressurized. Therefore, the heat fixing belt 162 may be pressed toward the pressure roll 161 by the pressing pad 164. The pressure roll 161 may be pressed toward the heat fixing belt 162 side.

  The material of the pressure pad 164 is, for example, a resin such as silicone rubber, fluororubber, polyimide resin, polyamide resin, phenol resin, PES resin (polyethersulfone), PPS resin (polyphenylene sulfide), or a metal such as iron or aluminum. Etc. The resin may further contain conductive particles such as carbon black, graphite, and metal powder.

Further, a low friction member (not shown) may be provided between the heat fixing belt 162 and the pressure pad 164 in order to reduce the sliding resistance (friction) between the inner peripheral surface of the heat fixing belt 162 and the pressure pad 164. Good. In this case, the low friction member constitutes a sliding member that slides on the inner peripheral surface of the heat fixing belt 162.
The low friction member may be composed of a single layer or may be composed of a plurality of layers. Examples of the material of the low friction member include a sintered molded PTFE resin sheet, a glass fiber sheet impregnated with a fluororesin, and a laminated sheet in which a fluororesin film sheet is heat-sealed and sandwiched between glass fibers.
Moreover, it is preferable that the low friction member is provided with a lubricating oil permeation preventive layer that suppresses the depletion of the lubricating oil. Examples of the material for the lubricating oil permeation preventive layer include heat resistant resin films and metal films that have heat resistance and do not allow lubricating oil to permeate.
In the case where the low friction member is not installed, the pressure pad 164 is made of a resin or metal containing particles capable of imparting conductivity, for example, so that the surface contacting the inner peripheral surface of the heat fixing belt 162 has conductivity. Etc. are preferable.

  A lubricating oil application member may be provided inside the heat fixing belt 162 in order to reduce the frictional resistance between the heat fixing belt 162 and each member in contact with the inner surface of the heat fixing belt 162 such as the pressure pad 164. Lubricating oil (for example, the lubricating oil listed in the first embodiment) is supplied to the inner peripheral surface of the heat fixing belt 162 by the lubricating oil application member.

Belt running guide and heating element The belt running guide 163 and the belt running auxiliary guide 166 are provided in an arc shape along the shape of the heat fixing belt 162 inside the heat fixing belt 162, and the heat fixing belt 162 can move around. I support you.
The material of the belt traveling guide 163 and the belt traveling auxiliary guide 166 is, for example, heat-resistant resin such as polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), and further durability. And a filler for reducing the friction coefficient added to the heat-resistant resin.

A heating element 169 is provided between the belt running guide 163 and the heat fixing belt 162 as a heating source for applying heat to the heat fixing belt 162.
The heating element 169 has, for example, an arc shape so as to follow the shape of the heat fixing belt 162. As the heating element, for example, a resistance heating element that generates Joule heat by supplying electric power is sandwiched between a pair of support plates, and heat generated from the resistance heating element is heated and fixed on the heating and fixing belt 162 via the support plate. The mode transmitted to is mentioned. The material of the support plate is preferably a metal such as aluminum or stainless steel from the viewpoint of heat transfer. The heating source of the fixing device 160 is not limited to a heating element, and for example, a known heating source such as a halogen lamp may be used.

Next, the operation of the fixing device 160 will be described.
In the fixing device 160, the pressure roll 161 is rotated in the direction of arrow S by a drive motor (not shown), for example, and the heat fixing belt 162 is driven in the direction of arrow R opposite to the rotation direction of the pressure roll 161 by following this rotation. Rotate. That is, for example, while the pressure roll 161 rotates counterclockwise in FIG. 3, the heat fixing belt 162 rotates clockwise. The rotation speed is not particularly limited, and is set to, for example, a surface speed of 250 mm / second.

  Then, a sheet K (an example of a recording medium) on which an unfixed toner image G is formed is guided by a fixing inlet guide 156A and conveyed to a nip portion formed by a heat fixing belt 162 and a pressure roll 161. Is done. When the sheet K passes through the nip portion, the toner image G on the sheet K is applied with pressure and heat acting on the nip portion, and is further guided and discharged by the fixing outlet guide 156B. Image G is fixed.

<Image forming apparatus>
The image forming apparatus according to the present embodiment includes the fixing device according to the present embodiment.
The image forming apparatus according to the present embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, and an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the image carrier. And developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image, and transfer means for transferring the toner image to the surface of the recording medium. And a fixing unit that includes the fixing device according to the present embodiment and fixes the toner image to the recording medium.

  The image forming apparatus according to the present embodiment is, for example, a normal monocolor image forming apparatus in which only a single color toner is accommodated in a developing device, and a toner image held on an image holding body is sequentially subjected to primary transfer to an intermediate transfer body. Examples thereof include a color image forming apparatus that repeats and a tandem type color image forming apparatus in which a plurality of image carriers each having a developing device for each color are arranged in series on an intermediate transfer member.

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

FIG. 4 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment. The image forming apparatus shown in FIG. 4 is an image forming apparatus applied to the fixing device according to the present embodiment.
As shown in FIG. 4, the image forming apparatus 100 according to the present embodiment is, for example, a so-called tandem method, and around four image carriers 101 a to 101 d made of an electrophotographic photosensitive member along the rotation direction. In order, charging devices 102a to 102d, exposure devices 114a to 114d, developing devices 103a to 103d, primary transfer devices (primary transfer rolls) 105a to 105d, and image carrier cleaning devices 104a to 104d are arranged. Note that a static eliminator may be provided in order to remove residual potential remaining on the surfaces of the image carriers 101a to 101d after transfer.

  The intermediate transfer belt 107 is supported while applying tension by the support rolls 106a to 106d, the drive roll 111, and the opposing roll 108, thereby forming an endless belt unit 107b. With the support rolls 106a to 106d, the driving roll 111, and the opposing roll 108, the intermediate transfer belt 107 is in contact with the surfaces of the image carriers 101a to 101d, and the image carriers 101a to 101d and the primary transfer rollers 105a to 105d. Can be moved in the direction of arrow A. A portion where the primary transfer rolls 105a to 105d come into contact with the image carriers 101a to 101d via the intermediate transfer belt 107 is a primary transfer portion, and a primary contact portion between the image carriers 101a to 101d and the primary transfer rollers 105a to 105d is a primary transfer portion. A transfer voltage is applied.

  As a secondary transfer device, a counter roll 108 and a secondary transfer roll 109 are arranged to face each other with an intermediate transfer belt 107 and a secondary transfer belt 116 interposed therebetween. The secondary transfer belt 116 is supported by a secondary transfer roll 109 and a support roll 106e. The recording medium 115 such as paper moves in the direction of the arrow B while being in contact with the surface of the intermediate transfer belt 107 while being in contact with the surface of the intermediate transfer belt 107, and then passes through the fixing device 110. A portion where the secondary transfer roll 109 comes into contact with the opposing roll 108 via the intermediate transfer belt 107 and the secondary transfer belt 116 is a secondary transfer portion, and the secondary transfer roll 109 and the opposing roll 108 are in contact with the secondary transfer portion. A transfer voltage is applied. Further, intermediate transfer belt cleaning devices 112 and 113 are arranged so as to come into contact with the intermediate transfer belt 107 after transfer.

  In the multi-color image forming apparatus 100 having this configuration, the image carrier 101a rotates in the direction of arrow C, and after the surface is charged by the charging device 102a, the first color is exposed by the exposure device 114a such as laser light. An electrostatic charge image is formed. The formed electrostatic image is developed (developed) with a developer containing toner by a developing device 103a containing toner corresponding to the color to form a toner image. The developing devices 103a to 103d contain toners (for example, yellow, magenta, cyan, and black) corresponding to the electrostatic image of each color.

  The toner image formed on the image carrier 101a is electrostatically transferred (primary transfer) onto the intermediate transfer belt 107 by the primary transfer roll 105a when passing through the primary transfer portion. Thereafter, the toner images of the second color, the third color, and the fourth color are primarily transferred onto the intermediate transfer belt 107 holding the toner image of the first color by the primary transfer rolls 105b to 105d so that the toner images of the second color, the third color, and the fourth color are sequentially superimposed. Finally, a multi-colored multiple toner image is obtained.

  The multiple toner images formed on the intermediate transfer belt 107 are electrostatically collectively transferred to the recording medium 115 when passing through the secondary transfer portion. The recording medium 115 onto which the toner image has been transferred is conveyed to the fixing device 110, and after being fixed by heating and pressing, or heating or pressing, the recording medium 115 is discharged outside the apparatus.

  Residual toner is removed from the image carriers 101a to 101d after the primary transfer by the image carrier cleaning devices 104a to 104d. On the other hand, residual toner is removed from the intermediate transfer belt 107 after the secondary transfer by the intermediate transfer belt cleaning devices 112 and 113 to prepare for the next image forming process.

Image carrier As the image carriers 101a to 101d, known electrophotographic photosensitive members are widely used. As the electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer made of an inorganic material, an organic photoreceptor having a photosensitive layer made of an organic material, or the like is used. In organic photoconductors, a function-separated type organic photoconductor that stacks a charge generation layer that generates charge upon exposure and a charge transport layer that transports charge, or a single layer that performs the function of generating charge and the function of transporting charge Type organic photoreceptors are preferably used. In addition, as the inorganic photoconductor, a photoconductive layer composed of amorphous silicon is preferably used.

  The shape of the image carrier is not particularly limited, and a known shape such as a cylindrical drum shape, a sheet shape, or a plate shape is employed.

Charging device The charging devices 102a to 102d are not particularly limited, and are, for example, conductive (here, "conductive" in the charging device means, for example, a volume resistivity of less than 10 ⁷ Ωcm) or semiconductive. Contact-type charging using a roller, brush, film, rubber blade, or the like having the property (here, “semiconductive” in the charging device means, for example, a volume resistivity of 10 ⁷ Ωcm or more and 10 ¹³ Ωcm or less). Known chargers such as chargers, scorotron chargers using corona discharge and corotron chargers are widely used. Among these, a contact charger is preferable.

  The charging devices 102a to 102d normally apply a direct current to the image carriers 101a to 101d, but an alternating current may be further superimposed and applied.

Exposure Device There are no particular limitations on the exposure devices 114a to 114d, and for example, a light source such as a semiconductor laser light, LED (Light Emitting Diode) light, or liquid crystal shutter light is provided on the surface of the image carriers 101a to 101d. Alternatively, a known exposure apparatus such as an optical system apparatus that can perform imagewise exposure from these light sources via a polygon mirror is widely applied.

Developing device The developing devices 103a to 103d are selected according to the purpose. For example, a known developing device that develops a one-component developer or a two-component developer in a contact or non-contact manner using a brush or a roller can be used.

Intermediate transfer belt The intermediate transfer belt 107 is composed of a film-like pressure belt containing a resin such as polyimide, polyamide, and polyamideimide as a base layer and containing an appropriate amount of an antistatic agent such as carbon black. The volume resistivity is 10 ⁶ Ωcm or more and 10 ¹⁴ Ωcm or less, and the thickness is, for example, about 0.1 mm.

Primary transfer roll The primary transfer rolls 105a to 105d may be either a single layer or a multilayer. For example, in the case of a single layer structure, it is composed of a roll in which an appropriate amount of conductive particles such as carbon black is blended in foamed or non-foamed silicone rubber, urethane rubber, EPDM, or the like.

Image carrier cleaning device The image carrier cleaning devices 104a to 104d are for removing residual toner adhering to the surfaces of the image carriers 101a to 101d after the primary transfer process. Or roll cleaning or the like is used. Among these, it is desirable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

Secondary transfer roll The layer structure of the secondary transfer roll 109 is not particularly limited. For example, in the case of a three-layer structure, the secondary transfer roll 109 includes a core layer, an intermediate layer, and a coating layer covering the surface. The core layer is a foamed material such as silicone rubber, urethane rubber, or EPDM in which conductive particles are dispersed, and the intermediate layer is composed of these non-foamed materials. Examples of the material for the coating layer include tetrafluoroethylene-hexafluoropropylene copolymer or perfluoroalkoxy resin. The volume resistivity of the secondary transfer roll 109 is desirably 10 ⁷ Ωcm or less. Moreover, it is good also as a two-layer structure except an intermediate | middle layer.

-Counter roll The counter roll 108 forms the counter electrode of the secondary transfer roll 109. The layer structure of the facing roll 108 may be either a single layer or a multilayer. For example, in the case of a single layer structure, it is composed of a roll in which an appropriate amount of conductive particles such as carbon black is blended in silicone rubber, urethane rubber, EPDM, or the like. In the case of a two-layer structure, it is composed of a roll in which the outer peripheral surface of the elastic layer made of the rubber material is covered with a high resistance layer.

  A voltage of 1 kV or more and 6 kV or less is normally applied to the core of the opposing roll 108 and the secondary transfer roll 109. Instead of applying a voltage to the core of the opposing roll 108, a voltage may be applied to the electrically conductive electrode member brought into contact with the opposing roll 108 and the secondary transfer roll 109. Examples of the electrode member include a metal roll, a conductive rubber roll, a conductive brush, a metal plate, or a conductive resin plate.

Intermediate transfer belt cleaning device As the intermediate transfer belt cleaning devices 112 and 113, brush cleaning, roll cleaning, or the like is used in addition to a cleaning blade. Among these, it is desirable to use a cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

<Example 1>
As a polyimide precursor composition, 20% by mass of polyamic acid obtained by polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) A 1,3-dimethyl-2-imidazolidinone (DMI) solution having a solid content concentration of 1 was prepared.
This solution was applied to a Φ30 mm aluminum pipe (surface Ra blasted to 0.3 mm) with a blade applied to a thickness of 80 μm after film formation, and then rotated at 130 ° C. for 40 minutes while being rotated. The residual solvent amount was 50 mass%. Thereafter, a PFA dispersion was spray-coated and dried at 80 ° C. for 15 minutes. Next, as a baking step, the temperature was maintained at 330 ° C. for 30 minutes, returned to room temperature (25 ° C.) over 2 hours, and after demolding, both ends were cut to a predetermined length to produce a pressure fixing belt. The amount of residual solvent in the obtained pressure fixing belt was 1.5% by mass.

<Example 2>
As a polyimide precursor composition, 20% by mass of polyamic acid obtained by polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) A tetramethylurea solution having a solid content concentration of was prepared.
This solution was applied to a 30 mm Φ aluminum pipe (surface Ra blasted to 0.3 mm) with a blade applied to a thickness of 80 μm after film formation, and then dried at 100 ° C. for 20 minutes while being rotated. The residual solvent amount was 35% by mass. Thereafter, a PFA dispersion was spray-coated and dried at 80 ° C. for 15 minutes. Next, as a baking step, the temperature was maintained at 330 ° C. for 30 minutes, returned to room temperature (25 ° C.) over 2 hours, and after demolding, both ends were cut to a predetermined length to produce a pressure fixing belt. The amount of residual solvent in the obtained pressure fixing belt was 0.07% by mass.

<Example 3>
As a polyimide precursor composition, 20% by mass of polyamic acid obtained by polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) A 3-methoxy-N, N-dimethylpropanamide solution having a solid content concentration of 1 was prepared.
This solution was applied to a Φ30 mm aluminum pipe (surface Ra blasted to 0.3 mm) with a blade applied to a thickness of 80 μm after film formation, and then dried at 130 ° C. for 50 minutes while being rotated. The residual solvent amount was 60% by mass. Thereafter, a PFA dispersion was spray-coated and dried at 80 ° C. for 15 minutes. Next, as a baking step, the temperature was maintained at 330 ° C. for 30 minutes, returned to room temperature (25 ° C.) over 2 hours, and after demolding, both ends were cut to a predetermined length to produce a pressure fixing belt. The amount of residual solvent in the obtained pressure fixing belt was 3.0% by mass.

<Comparative Example 1>
As a polyimide precursor composition, 20% by mass of polyamic acid obtained by polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) An N-methylpyrrolidone (NMP) solution having a solid content concentration of 1 was prepared.
This solution was applied to a Φ30 mm aluminum pipe (surface Ra blasted to 0.3 mm) with a blade applied to a thickness of 80 μm after film formation, and then rotated at 130 ° C. for 35 minutes while being rotated. The residual solvent amount was adjusted to 48% by mass. Thereafter, a PFA dispersion was spray-coated and dried at 80 ° C. for 15 minutes. Next, as a baking step, the temperature was maintained at 330 ° C. for 30 minutes, returned to room temperature (25 ° C.) over 2 hours, and after demolding, both ends were cut to a predetermined length to produce a pressure fixing belt. The amount of residual solvent in the obtained pressure fixing belt was 1.1% by mass.

<Comparative Example 2>
As a polyimide precursor composition, 20% by mass of polyamic acid obtained by polymerizing 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) An N, N-diacetamide solution having a solid content concentration of 1 was prepared.
This solution was applied to a Φ30 mm aluminum pipe (surface Ra blasted to 0.3 mm) with a blade applied to a thickness of 80 μm after film formation, and then rotated at 130 ° C. for 35 minutes while being rotated. The residual solvent amount was adjusted to 48% by mass. Thereafter, a PFA dispersion was spray-coated and dried at 80 ° C. for 15 minutes. Next, as a baking step, the temperature was maintained at 330 ° C. for 30 minutes, returned to room temperature (25 ° C.) over 2 hours, and after demolding, both ends were cut to a predetermined length to produce a pressure fixing belt. The amount of residual solvent in the obtained pressure fixing belt was 1.5% by mass.

  In the above Examples and Comparative Examples, product name: EJ-CL700 manufactured by Mitsui DuPont Fluoro Chemical Co., Ltd. was used as the PFA dispersion.

[Evaluation]
-Measurement of indentation volume-
For the inner peripheral surface of the pressure-fixing belt obtained in each example and comparative example, the indenter indentation volume (115 ° triangular pyramid indenter, load 0.5 mN) by the nanoindentation method was used as an index of hardness. Measured by the method.

-Measurement of Young's modulus-
For the pressure-fixing belts obtained in the examples and comparative examples, the Young's modulus was measured by the method described above as an index of flexibility.

-Measurement of torque before and after 100kPV printing-
The pressure-fixing belt obtained in each of the examples and comparative examples is used as a pressure-fixing belt disposed opposite to a heat-fixing roll (heat roll) in a fixing unit of an image forming apparatus (DocuPrintCP400ps) manufactured by Fuji Xerox Co., Ltd. Installed. A sliding member is disposed on the inner peripheral surface of the pressure fixing belt nip so as to be pressed toward the nip direction, and lubricating oil (Shin-Etsu Chemical Co., Ltd.) is disposed on the inner peripheral surface of the pressure fixing belt. Industrial product, product name: KF-877) is applied.
Printing of 100 kPV (= 100,000 sheets) was performed with this image forming apparatus, and before and after that, the fixing unit was removed and the torque of the heat roll was measured.
The torque before the start of printing was 0.30 N · m. The torque difference after the start of printing and the torque difference before and after the start of printing are shown in Table 1 below.

As shown in Table 1, in Examples 1 to 3 containing the solvent included in the above-mentioned solvent group A as a solvent, Comparative Examples containing only N-methylpyrrolidone (NMP) or N, N-diacetamide as the solvent Compared to 1 and 2, the indentation volume of the indenter by the nanoindentation method is small, and it can be seen that the inner peripheral surface is hard. And in Examples 1-3, it turns out that the raise of the torque before and after printing of 100 kPV (= 100,000 sheets) is suppressed compared with Comparative Examples 1 and 2.
In addition, about the pressure fixing belts of Examples 1 to 3 and Comparative Examples 1 and 2, when the inner peripheral surface after printing of 100 kPV was observed, in Comparative Examples 1 and 2, wear progressed. In Examples 1 to 3, the occurrence of wear was not observed, or only a small amount of wear occurred.

56 Fixing entrance guide 60 Fixing device 61 Heating roll 62 Pressure fixing belt 63 Belt running guide 64 Press pad 64a Front clamping member 64b Peeling clamping member 65 Holding member 66 Halogen lamp 68 Low friction member 69 Temperature sensitive element 70 Peeling member 71 Peeling claw 72 Holding member 100 Image forming apparatus 101a, 101b, 101c, 101d Image carrier 102a, 102b, 102c, 102d Charging device 103a, 103b, 103c, 103d Developing device 104a, 104b, 104c, 104d Image carrier cleaning device 105a 105b, 105c, 105d Primary transfer rolls 106a, 106b, 106c, 106d Support roll 107 Intermediate transfer belt 107b Endless belt unit 108 Opposing roll 109 Secondary transfer roll 110 Fixing device 110A Base material 1 10B Elastic layer 110C Surface layer 111 Driving roll 112 Intermediate transfer belt cleaning device 114a, 114b, 114c, 114d Exposure device 115 Recording medium 116 Secondary transfer belt 156A Fixing inlet guide 156B Fixing outlet guide 160 Fixing device 161 Pressure roll 161A Core 161B Heat resistant elastic layer 161C Surface layer 162 Heat-fixing belt 163 Belt running guide 164 Press pad 165 Holder 166 Belt running assist guide 169 Heating element K Paper N Nipping area (nip)

Claims (7)

At least one resin selected from the group consisting of polyimide and polyamideimide, and at least one solvent selected from solvent group A consisting of a urea solvent, an alkoxy group-containing amide solvent, and an ester group-containing amide solvent a cylindrical base material that comprises a belt inner peripheral surface,
A surface layer disposed on the outer periphery of the substrate;
A fixing belt having:   The solvent a is tetramethylurea, tetraethylurea, 1,3-dimethyl-2-imidazolidinone, N, N-dimethylpropyleneurea, 3-methoxy-N, N-dimethylpropanamide, and 3-nbutoxy- The fixing belt according to claim 1, wherein the fixing belt is at least one solvent selected from a solvent group B consisting of N, N-dimethylpropanamide.   The fixing belt according to claim 1, wherein the solvent a is 1,3-dimethyl-2-imidazolidinone. 2. The inner peripheral surface of the substrate has a depth (indentation volume) of 0.06 μm ³ or less when a 115 ° triangular pyramid indenter is pushed with a load of 0.5 mN by a nanoindentation method. The fixing belt according to claim 3.   The fixing belt according to claim 1, wherein the base material further contains lubricating particles. A fixing belt according to any one of claims 1 to 5,
A sliding member that contacts the inner peripheral surface of the fixing belt and slides with the fixing belt that is rotationally driven;
A fixing rotator that is disposed to face the sliding member with the fixing belt interposed therebetween and pressurizes an outer peripheral surface of the fixing belt;
Have
A fixing device for fixing a toner image on the recording medium by sandwiching a recording medium having an unfixed toner image formed on the surface between the fixing belt and the fixing rotating body. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
A fixing unit comprising the fixing device according to claim 6 and fixing the toner image on the recording medium;
An image forming apparatus comprising: