JP2019060907A - Resin film for image forming apparatus, transfer device, fixing device, image forming apparatus, and method for manufacturing resin film - Google Patents

Abstract

To provide a resin film for an image forming apparatus that is excellent in adhesiveness between a polyimide resin layer and a silicone rubber layer.SOLUTION: A resin film 10 for an image forming apparatus comprises: a polyimide resin layer 10A; a silicone rubber layer 10B that is provided on the polyimide resin layer 10A; and a mixed boundary layer 10M that is present at the boundary between the polyimide resin layer 10A and silicone rubber layer 10B and contains polyimide resin and silicone rubber mixed therein.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a resin film for an image forming apparatus, a transfer device, a fixing device, an image forming apparatus, and a method of manufacturing a resin film.

  In an electrophotographic image forming apparatus (such as a copying machine, a facsimile, or a printer), a toner image formed on the surface of an image carrier is transferred to the surface of a recording medium, and the toner image transferred onto the recording medium is transferred. The image is formed by fixing on a recording medium by heating or the like. A resin film is used as a belt member or the like in such a transfer device for transferring the toner image to the recording medium and a fixing device for fixing the toner image to the recording medium.

  For example, Patent Document 1 discloses “a transfer sheet for transfer printing comprising a silicone rubber sheet laminated on one side of a substrate film, and the silicone rubber sheet is opened prior to lamination with the substrate film. It is a sheet heat-treated at a temperature of 100 ° C or higher in the system, and in the state after lamination of the base film and the silicone rubber sheet, each of the four corners when forming a 100 mm square laminated sheet is 1 mm or less There is disclosed a transfer sheet for transfer printing provided with flatness to be a floating amount.

  Further, in Patent Document 2, “Alkoxysilane of a specific structure is added to an organic solvent solution containing a polyamide acid having a specific structural unit, hydrolysis is performed simultaneously with condensation, and the resulting solution is applied to a substrate. Thereafter, a low modulus polyimide siloxane complex obtained by firing is disclosed.

  Further, in Patent Document 3, “a base material, a silicon oxide layer formed on the outer peripheral surface of the base material, a primer layer formed on the outer periphery of the silicon oxide layer, and an outer periphery of the primer layer Discloses a roller or belt for an image forming apparatus having an elastic layer.

JP, 2013-116577, A Japanese Patent Application Publication No. 06-207024 International Publication No. 2008/087695

  As a resin film for an image forming apparatus, for example, a resin film in which a silicone rubber layer is laminated on a polyimide resin layer is used. From the viewpoint of adhesion of the polyimide resin, conventionally, the surface of the polyimide resin layer is subjected to physical or chemical surface treatment, and then the silicone rubber layer is generally formed. However, since the surface treatment leads to complication of the production of the resin film, a resin film excellent in the adhesiveness between the polyimide resin layer and the silicone rubber layer without the surface treatment is desired.

  Therefore, the object of the present invention is to improve the adhesion between the polyimide resin layer and the silicone rubber layer as compared with a resin film having no mixed boundary layer in which the polyimide resin and the silicone rubber are mixed at the boundary between the polyimide resin layer and the silicone rubber layer. Providing a resin film for use in an image forming apparatus.

  The above-mentioned subject is solved by the following means. That is,

The invention according to claim 1 is
Polyimide resin layer,
A silicone rubber layer provided on the polyimide resin layer;
A mixed boundary layer which exists at the boundary between the polyimide resin layer and the silicone rubber layer and in which the polyimide resin and the silicone rubber are mixed;
And a resin film for an image forming apparatus.

The invention according to claim 2 is
The resin film according to claim 1, wherein an average thickness of the mixed boundary layer is 50 nm or more and 500 nm or less.

The invention according to claim 3 is
The resin film according to claim 1 or 2 whose imidation ratio of said polyimide resin layer is 80% or more and 100% or less.

The invention according to claim 4 is
The resin film according to any one of claims 1 to 3, wherein the polyimide resin layer contains an imidization accelerator.

The invention according to claim 5 is
The resin film according to claim 4, wherein the imidization accelerator is an amine compound.

The invention according to claim 6 is
The resin film according to any one of claims 1 to 5, wherein the polyimide resin layer contains a hydrophilic solvent.

The invention according to claim 7 is
The resin film according to claim 6, wherein the hydrophilic solvent is an aprotic polar solvent.

The invention according to claim 8 is
The resin film according to any one of claims 1 to 7, further comprising a layer containing a fluorine-containing resin on the silicone rubber layer.

The invention according to claim 9 is
The shape of the said resin film is an endless belt shape, The resin film of any one of Claims 1-8.

The invention according to claim 10 is
It has an endless belt-like resin film according to claim 9,
A transfer device for transferring a toner image formed on the surface of an image carrier to the surface of a recording medium.

The invention according to claim 11 is
An image carrier,
An image carrier toner image forming means for forming a toner image on the surface of the image carrier;
A transfer unit, comprising: the transfer device according to claim 10, for transferring the toner image to a surface of a recording medium;
An image forming apparatus comprising:

The invention according to claim 12 is
It has an endless belt-like resin film according to claim 9,
A fixing device for heating and fixing a toner image formed on a recording medium to the recording medium.

The invention according to claim 13 is
Recording medium toner image forming means for forming a toner image on the recording medium;
A fixing unit comprising the fixing device according to claim 12 and fixing the toner image to the recording medium.
An image forming apparatus comprising:

The invention according to claim 14 is
Applying a polyimide precursor solution and drying to form a polyimide precursor coating film;
Applying a silicone rubber solution onto the polyimide precursor coating film and drying to form a laminated coating film in which the silicone rubber coating film is laminated on the polyimide precursor coating film;
A heating step of heating the laminated coating film to imidize a polyimide precursor in the polyimide precursor coating film and baking a silicone rubber in the silicone rubber coating film;
The manufacturing method of the resin film which obtains the resin film of any one of Claims 1-9 which has the said mixed boundary layer through.

The invention according to claim 15 is
The method for producing a resin film according to claim 14, wherein the solvent content of the polyimide precursor coating film is 35% by mass or more and 65% by mass or less when the silicone rubber solution is applied.

The invention according to claim 16 is
The method for producing a resin film according to claim 14 or 15, wherein the heating temperature in the heating step is 150 ° C or more and 330 ° C or less.

The invention according to claim 17 is
The method for producing a resin film according to any one of claims 14 to 16, wherein the polyimide precursor solution contains an imidization accelerator.

The invention according to claim 18 is
The method for producing a resin film according to claim 17, wherein the imidization accelerator is an amine compound.

The invention according to claim 19 is
The ratio [B / A] of the amount [A] of COOH group in the polyimide precursor in the polyimide precursor solution and the amount [B] of COOH group in the polyimide resin in the mixed boundary layer after the heating step is The method for producing a resin film according to any one of claims 14 to 18, which is 1/100 or more and 1/2 or less.

According to the invention according to claim 1, 8 or 9, compared to a resin film which does not have a mixed boundary layer in which the polyimide resin and the silicone rubber are mixed at the boundary between the polyimide resin layer and the silicone rubber layer, There is provided a resin film for an image forming apparatus excellent in adhesion to a silicone rubber layer.
According to the invention as set forth in claim 2, a resin film for an image forming apparatus is provided which is excellent in the adhesiveness between the polyimide resin layer and the silicone rubber layer as compared to the resin film in which the average thickness of the mixed boundary layer is less than 50 nm. Be done.
According to the third aspect of the present invention, a resin film for an image forming apparatus having high mechanical strength is provided as compared to a resin film in which the imidization ratio of the polyimide resin layer is less than 80%.
According to the invention concerning Claim 4 or 5, the resin film for image forming apparatuses which has high mechanical strength compared with the resin film which does not contain an imidation promoter in a polyimide resin layer is provided.
According to the invention as set forth in claim 6 or 7, for an image forming apparatus having excellent adhesion between the polyimide resin layer and the silicone rubber layer, as compared to a resin film provided with a polyimide resin layer containing only a hydrophobic solvent as a solvent. A resin film is provided.

According to the invention as set forth in claim 10 or 11, only the resin film which does not have the mixed boundary layer in which the polyimide resin and the silicone rubber are mixed at the boundary between the polyimide resin layer and the silicone rubber layer as an endless belt-like film member A transfer apparatus or an image forming apparatus is provided in which peeling at the boundary between the polyimide resin layer and the silicone rubber layer with the resin film is suppressed even after repeated transfer of the image, as compared with the case of having the
According to the invention as set forth in claim 12 or 13, only the resin film which does not have the mixed boundary layer in which the polyimide resin and the silicone rubber are mixed at the boundary between the polyimide resin layer and the silicone rubber layer as an endless belt-like film member A fixing device or an image forming apparatus is provided in which peeling at the boundary between the polyimide resin layer and the silicone rubber layer with the resin film is suppressed even after repeated fixing of the image, as compared with the case where the image forming apparatus has the above.

According to the invention of claim 14, the polyimide precursor solution is applied and dried to form a polyimide precursor coating, and this is heated to perform imidization of the polyimide precursor in the polyimide precursor coating. Then, apply a silicone rubber solution on the polyimide precursor coating film after imidization and dry it to form a silicone rubber coating, and heat it to bake the silicone rubber in the silicone rubber coating. There is provided a method for producing a resin film which can obtain a resin film for an image forming apparatus which is excellent in adhesion between a polyimide resin layer and a silicone rubber layer as compared to a method for producing a resin film.
According to the invention as set forth in claim 15, compared with the case where the solvent content of the polyimide precursor coating film when applying the silicone rubber solution is less than 35% by mass, the adhesiveness between the polyimide resin layer and the silicone rubber layer is There is provided a method of producing a resin film from which a resin film for an excellent image forming apparatus can be obtained.
According to the invention as set forth in claim 16, as compared to the case where the heating temperature in the heating step exceeds 330 ° C., the production of a resin film from which a resin film for an image forming apparatus in which thermal deterioration of the silicone rubber layer is suppressed is obtained. A method is provided.
According to the invention as set forth in claim 17 or 18, the resin film for the image forming apparatus in which the thermal deterioration of the silicone rubber layer is suppressed as compared with the method for producing the resin film which does not contain the imidation accelerator in the polyimide precursor solution. There is provided a method of producing a resin film, wherein
According to the invention of claim 19, the amount [A] of COOH group in the polyimide precursor in the polyimide precursor solution and the amount [B] of COOH group in the polyimide resin in the mixed boundary layer after the heating step Provided is a method for producing a resin film which can provide a resin film for an image forming apparatus having excellent adhesion between a polyimide resin layer and a silicone rubber layer as compared with the case where the ratio [B / A] exceeds 1/2. .

It is a schematic cross section which shows an example of the resin film which concerns on this embodiment. It is a schematic cross section which shows an example of the resin film which concerns on this embodiment formed in endless belt shape. FIG. 1 is a schematic configuration view illustrating an example of a fixing device according to a first embodiment. FIG. 7 is a schematic configuration view illustrating an example of a fixing device according to a second embodiment. FIG. 1 is a schematic configuration view showing an example of an image forming apparatus according to the present embodiment.

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

[Resin film for image forming apparatus]
A resin film for an image forming apparatus according to the present embodiment (hereinafter, also simply referred to as “resin film”) comprises a polyimide resin layer, a silicone rubber layer provided on the polyimide resin layer, the polyimide resin layer, and It exists in the boundary of a silicone rubber layer, and has a mixed boundary layer which polyimide resin and silicone rubber mix.

According to the resin film concerning this embodiment, it is excellent in the adhesiveness of a polyimide resin layer and a silicone rubber layer by having said composition.
The reason is presumed as follows.

Conventionally, in an image forming apparatus, a transfer device for transferring a toner image formed on the surface of an image carrier to the surface of a recording medium, and fixing on a recording medium by heating the toner image formed on the recording medium A resin film is used as a film-like member used for an apparatus etc. Then, as this resin film, a resin film in which a silicone rubber layer is laminated as an elastic layer on a polyimide resin layer having high heat resistance and high strength is used.
However, since the polyimide resin has low reactivity with silicone rubber, when forming the silicone rubber layer on the surface of the polyimide resin layer, physical or chemical surface treatment is applied to the polyimide resin layer from the viewpoint of improving adhesion. Was generally performed. Specifically, a surface treatment with a primer and a method of activating the surface of a polyimide resin layer by ozone treatment or the like are performed.
However, providing such a surface treatment step also complicates the production of the resin film, and therefore, a resin excellent in the adhesion between the polyimide resin layer and the silicone rubber layer even if the surface treatment is not applied. A film is desired.

On the other hand, according to the present embodiment, excellent adhesion between the polyimide resin layer and the silicone rubber layer can be obtained. The polyimide resin has functional groups such as NH ₂ group (amino group) and COOH group (carboxy group) slightly in its molecular chain, and these functional groups are Si-OH groups (silanol group) which silicone rubber has. Etc.) is considered to form a bond with a functional group such as Here, as described above, the resin film according to the present embodiment has a mixed boundary layer in which the polyimide resin and the silicone rubber are mixed, between the polyimide resin layer and the silicone rubber layer. Therefore, a bond formed by a functional group (amino group, carboxy group, etc.) in the polyimide resin and a functional group (silanol group etc.) in the silicone rubber is formed only in the surface in contact with both layers, ie, in a two-dimensional region. Instead, it is formed of the entire mixed boundary layer, that is, a three-dimensional area. As a result, more bonds between functional groups are formed, and it is considered that excellent adhesion between the polyimide resin layer and the silicone rubber layer can be obtained.

-Achieving method (production method of resin film)-
Here, a method of obtaining a resin film having a mixed boundary layer in which the polyimide resin and the silicone rubber are mixed is described at the boundary between the polyimide resin layer and the silicone rubber layer. Although not particularly limited, for example, a resin film having a mixed boundary layer can be obtained by the following manufacturing method.

The manufacturing method which obtains a resin film through each process of following (1) thru | or (3).
(1) A step of applying a polyimide precursor solution and drying to form a polyimide precursor coating film
(2) A step of applying a silicone rubber solution on a polyimide precursor coating film and drying it to form a laminated coating film in which the silicone rubber coating film is laminated on the polyimide precursor coating film
(3) A heating step of heating the laminated coating to imidize the polyimide precursor in the polyimide precursor coating and baking the silicone rubber in the silicone rubber coating

  As in the above method, a silicone rubber solution is applied on the coating film of the polyimide precursor before the imidization reaction, and the imidization reaction of the polyimide precursor and the baking (dehydration condensation reaction) of the silicone rubber are performed by one heating step. By carrying out, the silicone rubber solution penetrates to the polyimide precursor coating film side. In the region into which the silicone rubber solution penetrates, a bond is formed by the functional group (amino group, carboxy group etc.) in the polyimide resin and the functional group (silanol group etc.) in the silicone rubber, whereby the polyimide resin layer and the silicone rubber layer And a mixed boundary layer is formed between them.

In addition, when a resin film is manufactured by said manufacturing method, silicone rubber contacts with the polyimide precursor before imidation reaction. That is, the silicone rubber comes in contact with the polyimide precursor in a state in which NH ₂ groups (amino groups) and COOH groups (carboxy groups) before being consumed in the imidization reaction are abundantly present in the molecular chain. Therefore, by producing a resin film by the above production method, it is considered that more bonds between functional groups are formed, and the adhesiveness between the polyimide resin layer and the silicone rubber layer can be more easily enhanced.

  When the boundary between the polyimide resin layer and the silicone rubber layer of the resin film produced by the above-mentioned production method is enlarged and observed (for example, observed by STEM, TEM, etc.), no clear borderline is observed, and the polyimide resin and silicone rubber The area where it was mixed is observed.

  Here, each process of (1) to (3) in the manufacturing method of the said resin film is each demonstrated.

(1) Step of applying and drying a polyimide precursor solution to form a polyimide precursor coating film First, as a coating solution for forming a polyimide resin layer, for example, various materials serving as raw materials for the polyimide resin described later can be contained in a solvent Prepare a polyimide precursor solution dissolved or dispersed therein.
In the case of a resin film for applications where conductivity is required (for example, a transfer belt used in a transfer device), the polyimide precursor solution may further contain a conductive agent.

In addition, a mold for applying the above-mentioned coating solution is prepared. For example, in the case of forming an endless belt-like resin film, a cylindrical mold is prepared, and a polyimide precursor solution is applied to the outer peripheral surface of the mold. Examples of the coating method include usual methods such as blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method and curtain coating method.
The polyimide precursor coating film is formed by drying while rotating the mold on which the polyimide precursor solution is applied.

· Solvent content rate (solvent residual rate)
35 mass% or more and 65 mass% or less are preferable, and, as for the solvent content rate (solvent residual rate) of a polyimide precursor coating film before apply | coating a silicone rubber solution, 40 mass% or more and 60 mass% or less are more preferable, 45 mass% % Or more and 55% by mass or less is more preferable.
When the solvent content is 35% by mass or more, the silicone rubber solution coated on the polyimide precursor coating film easily penetrates, and as a result, the mixed boundary layer is easily formed. On the other hand, when the solvent content is 65% by mass or less, the flowability is reduced, the polyimide precursor coating film easily holds its shape, and the heating step (baking step) can be easily performed.

  The solvent content (solvent residual rate) can be measured by thermogravimetric analysis. Specifically, the DTG-60 / 60H thermal analyzer (manufactured by Shimadzu Corporation) is used to calculate the rate of decrease in mass before and after the temperature of the measurement sample is raised from room temperature (20 ° C.) to 250 ° C. .

-Imidation promoter It is preferable to make the polyimide precursor solution contain the imidation promoter which has the effect | action which promotes the imidation reaction of a polyimide precursor.
The temperature range in which the polyimide precursor undergoes an imidization reaction is generally higher than the temperature range in which the silicone rubber undergoes a dehydration condensation reaction. In the above resin film manufacturing method, the imidization reaction of the polyimide precursor and the dehydration condensation reaction of the silicone rubber are carried out in one heating step, but the temperature at which the heating temperature at that time is simply caused to cause the imidization reaction. If set in the region, the silicone rubber after dehydration condensation may be exposed to a higher temperature environment and thermally degraded. Therefore, the imidization accelerator is added to the polyimide precursor solution to lower the temperature at which the imidization reaction occurs, and to lower the heating temperature in the heating step (baking step), thereby suppressing the thermal deterioration of the silicone rubber. Is preferred.

  As the imidation promoter, an amine compound (more preferably an organic amine compound) is preferable. Specific examples of the amine compound will be described later.

-Hydrophilic solvent As a solvent used for a polyimide precursor solution, a hydrophilic solvent is preferable.
Since the polyimide precursor coating film becomes hydrophilic when the polyimide precursor solution contains a hydrophilic solvent, the Si-OH group (silanol group) in the silicone rubber solution applied on the polyimide precursor coating is polyimide It becomes easy to align with the interface side with the precursor coating film. As a result, many bonds are easily formed due to the functional group in the polyimide precursor and the silanol group in the silicone rubber, and the adhesion between the polyimide resin layer and the silicone rubber layer can be easily enhanced.

Hydrophilic means a property having an affinity for water. More specifically, the hydrophilic solvent means that the solvent is in a melted state without being separated when the solvent 50 g is added to 100 ml of pure water and stirred at a temperature of 25 ° C.
Examples of the hydrophilic solvent include aprotic polar solvents and protic polar solvents. Among these, aprotic polar solvents are preferred.
In addition, as a non-protonic polar solvent, one having a boiling point of 150 ° C. or more and 300 ° C. or less is preferable, and a solvent having a dipole moment of 3.0 D or more and 5.0 D or less is preferable. Specifically, N-methyl-2-pyrrolidone (NMP), N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), dimethylsulfoxide (DMSO), hexamethylenephosphoramide (HMPA) , N-methylcaprolactam, N-acetyl-2-pyrrolidone and the like.

(2) A step of applying a silicone rubber solution on the polyimide precursor coating film and drying to form a laminated coating film in which the silicone rubber coating film is laminated on the polyimide precursor coating film As a coating liquid for forming, for example, a silicone rubber solution in which various materials serving as raw materials of silicone rubber described below are dissolved or dispersed in a solvent is prepared.
In the case of a resin film for applications where conductivity is required (for example, a transfer belt used in a transfer device), a silicone rubber solution may further contain a conductive agent.

The silicone rubber solution is applied onto a polyimide precursor coating formed on a mold. Examples of the coating method include the above-described coating methods listed as the coating method of the polyimide precursor solution. Thereafter, the applied silicone rubber solution is dried while rotating the mold to obtain a laminated coating film in which the silicone rubber coating film is laminated on the polyimide precursor coating film.
In addition, although the solvent content rate (solvent residual rate) of a silicone rubber coating film is not specifically limited, For example, 1 to 50 mass% is preferable, and 1 to 20 mass% is more preferable.

(3) Heating step of heating the laminated coating to imidize the polyimide precursor in the polyimide precursor coating and baking the silicone rubber in the silicone rubber coating Next, the obtained laminated coating is heated Baking. In this heating step, the imidization reaction of the polyimide precursor and the dehydration condensation reaction of the silicone rubber are performed.

-Heating (baking) temperature The heating temperature (baking temperature) in the heating step is a point of favorably causing the imidization reaction of the polyimide precursor and the dehydration condensation reaction of the silicone rubber while suppressing the thermal deterioration of the silicone rubber. Therefore, 150 ° C. or more and 330 ° C. or less are preferable, 180 ° C. or more and 300 ° C. or less are more preferable, and 200 ° C. or more and 250 ° C. or less are more preferable.
Moreover, 120 minutes or more and 360 minutes or less are preferable, and, as for the heating time in a heating process, 180 minutes or more and 300 minutes or less are more preferable.

  As a heating method, for example, a known heating method such as a method of heating a laminated coating film in a baking furnace (a radiation heating furnace or the like), a method of heating from one side or both sides with a heater, a halogen lamp or the like is applied. In addition, the method of heating from the single side | surface by the side of a polyimide precursor coating film from a viewpoint of making it easy to suppress the thermal deterioration of silicone rubber is preferable.

-Imidation ratio The imidization ratio of the polyimide resin layer formed by the heating step is preferably 80% to 100% from the viewpoint of heat resistance and strength (especially mechanical strength) of the polyimide resin layer, and 85% More than 100% is more preferable, and 90% or more and 100% or less is more preferable.

Here, the imidation ratio is determined by infrared absorption spectrum (IR) method as follows.
The polyimide resin layer is measured by a transmission method using an IR apparatus (FT-730 manufactured by Horiba, Ltd.), and a spectral ratio indicating imidation (for example, an absorption peak derived from an imide ring and an aromatic ring as an internal standard) The imidation ratio is calculated from the absorption peak etc. of origin.

-COOH group amount In the resin film according to the present embodiment, many bonds are formed by the functional group (amino group, carboxy group etc.) in the polyimide resin and the functional group (silanol group etc.) in the silicone rubber in the mixed boundary layer It is preferable from the viewpoint of adhesion improvement.
Therefore, the amount [A] of COOH group (carboxy group) in the polyimide precursor in the polyimide precursor solution and the amount [B] of COOH group (carboxy group) in the polyimide resin in the mixed boundary layer after the heating step The ratio [B / A] is preferably 1/100 or more and 1/2 or less, more preferably 1/50 or more and 1/3 or less, and still more preferably 1/20 or more and 1/4 or less.
That the ratio [B / A] is 1/2 or less is considered to indicate that the amount of COOH groups is reduced to a rate calculated from the imidization rate of the polyimide resin or more, that is, with the polyimide resin It is an indicator that many bonds between functional groups with silicone rubber are formed. This makes it easy to obtain excellent adhesion between the polyimide resin layer and the silicone rubber layer.
On the other hand, when the ratio [B / A] is 1/100 or more, the effect of securing film strength by the progress of imidization in the mixed boundary layer can be easily obtained.

The amount of COOH groups [A] in the polyimide precursor in the polyimide precursor solution and the amount of COOH groups [B] in the polyimide resin in the mixed boundary layer after the heating step are measured by the following method.
The amount of COOH group [A] and the amount of COOH group [B] are determined by measuring the amount of COOH group from the detection of carboxylic acid. In particular, the amount of COOH group [B] is obtained by sputtering a layer on the polyimide resin layer side in which a thin silicone rubber layer cohesively broken by forced peeling is left using TOF-SIMS (manufactured by ULVAC-PHI, PHInanoTOF II) Measure while digging the surface, and measure the amount of COOH group from the detection of carboxylic acid.

-Thickness of Mixed Boundary Layer In the resin film according to the present embodiment, the average thickness of the mixed boundary layer is preferably 50 nm or more and 500 nm or less, more preferably 100 nm or more and 500 nm or less, and still more preferably 150 nm or more and 500 nm or less.
When the average thickness of the mixed boundary layer is 50 nm or more, excellent adhesion between the polyimide resin layer and the silicone rubber layer can be easily obtained. On the other hand, when the average thickness of the mixed boundary layer is 500 nm or less, the effects of the strength of the polyimide resin layer and the high elasticity of the silicone rubber layer can be easily obtained.

The thickness (average thickness) of the mixed boundary layer is measured by the following method.
A transmission image is taken using a TEM apparatus (Hitachi High-Tech Science H-7500), and a region different in form between the polyimide resin layer and the silicone rubber layer is grasped, and the film thickness of the region is measured.

The resin film obtained in this manner is removed from the mold and demolded to obtain the resin film according to the present embodiment.
In the above method, the resin film was produced by applying in the order of polyimide precursor solution-silicone rubber solution on the outer peripheral surface of the cylindrical mold, but the silicone rubber was formed on the inner peripheral surface side of the cylindrical mold. The resin film may be prepared by applying in order of solution-polyimide precursor solution.

The obtained resin film may be subjected to surface treatment such as polishing and etching on the outer peripheral surface and the inner peripheral surface after demolding.
Moreover, the aspect by which the other layer was further laminated may be sufficient as the resin film which concerns on this embodiment. For example, the resin film of the aspect which provided the release layer further on the silicone rubber layer may be sufficient.

-Composition of resin film-
Hereinafter, the configuration of the resin film according to the present embodiment will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an example of a resin film according to the present embodiment. The resin film described in FIG. 1 is, for example, a resin film having an endless belt shape.

For example, as shown in FIG. 1, the resin film 10 according to the present embodiment has a polyimide resin layer 10A as a base and a silicone rubber layer 10B as an elastic layer provided on the polyimide resin layer 10A. In addition, the mixed boundary layer 10M in which the polyimide resin and the silicone rubber are mixed is provided between the polyimide resin layer 10A and the silicone rubber layer 10B.
When the boundary between the polyimide resin layer 10A and the silicone rubber layer 10B of the resin film 10 is enlarged and observed by STEM, TEM, etc., no clear boundary line is observed, but a region where the polyimide resin and silicone rubber are mixed is observed. Ru.

  In the present embodiment, the layer configuration of the resin film is not limited to this, and other layers may be further provided. For example, a surface layer (for example, a layer containing a fluorine-containing resin) may be further provided on the silicone rubber layer 10B.

Here, a resin film having a surface layer (such as a layer containing a fluorine-containing resin) on the silicone rubber layer will be further described with reference to the drawings.
FIG. 2 is a schematic cross-sectional view showing another example of the resin film according to the present embodiment. The resin film shown in FIG. 2 is an endless belt-like resin film, and a polyimide resin layer 110A, a silicone rubber layer 110B provided on the polyimide resin layer 110A, and a surface layer 110C provided on the silicone rubber layer 110B. And.
Although not shown in FIG. 2, a clear boundary line is not observed at the interface between the polyimide resin layer 110A and the silicone rubber layer 110B, and a mixed boundary layer in which a polyimide resin and a silicone rubber are mixed between both layers. Exists.

  Then, the component of the resin film which concerns on this embodiment is demonstrated in detail. In addition, the code | symbol is abbreviate | omitted and demonstrated.

(Polyimide resin layer)
The polyimide resin layer contains a polyimide resin (for example, a wholly aromatic polyimide resin, an alicyclic polyimide resin, a polyimide resin containing a fluorine group, etc.) as a main component. In addition, containing as a main component represents that it occupies 50 mass% or more with respect to all the resin components contained in a polyimide resin layer.

  The polyimide resin layer may contain other resins (for example, polyamide imide resin, polyether imide resin, etc.). However, the content of the polyimide resin is 50% by mass or more, preferably 80% by mass or more, and more preferably 95% by mass or more based on all resin components.

-Polyimide resin As a polyimide resin, the imidate of the polyamic acid (polyamic acid) which is a polymer of tetracarboxylic dianhydride and a diamine compound is mentioned, for example. Specifically, as the polyimide resin, an equimolar amount of tetracarboxylic dianhydride and a diamine compound is polymerized in a solvent to obtain a solution of polyamic acid, which is obtained by imidizing the polyamic acid It can be mentioned.

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

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

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

On the other hand, as specific examples of diamine compounds, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3'-dichlorobenzidine, 4,4'-diaminodiphenyl sulfide 3,3'-Diaminodiphenyl sulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl 4,4'-biphenyldiamine, benzidine, 3,3'-dimethylbenzidine 3,3'-Dimethoxybenzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylpropane, 2,4-bis (β-amino tert-butyl) toluene, bis (p-β-amino- Tert-Butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis p- (1,1-Dimethyl-5-amino-pentyl) benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di (p-aminocyclohexyl) methane Hexamethylenediamine, Heptamethylenediamine, Octamethylenediamine, Nonamethylenediamine, Decamethylenediamine, Diaminopropyltetramethylene, 3-Methylheptamethylenediamine, 4,4-Dimethylheptamethylenediamine, 2,11-Diaminododecane, 1 , 2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2, 17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, Piperazine, H ₂ N (CH ₂ ) ₃ O (CH ₂ ) ₂ O (CH ₂ ) NH ₂ , H ₂ N (CH ₂ ) ₃ S (CH ₂ ) ₃ NH ₂ , H ₂ N (CH ₂ ) ₃ N (CH ₃ ) ₂ (CH ₂ ) ₃ NH _{2 and the} like.

  As a solvent at the time of carrying out the polymerization reaction of tetracarboxylic dianhydride and diamine, a polar solvent (organic polar solvent) is mentioned suitably from the point of solubility etc. As the polar solvent, N, N-dialkylamides are preferable, and specifically, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylformamide having low molecular weight thereof is preferable. And N, N-diethylacetamide, N, N-dimethylmethoxyacetamide, dimethylsulfoxide, hexamethylphosphortriamide, N-methyl-2-pyrrolidone, pyridine, tetramethylene sulfone, dimethyl tetramethylene sulfone and the like. One or more of these may be used in combination.

-Imidization promoter It is preferable that the polyimide resin layer contains an imidation promoter in the viewpoint of promoting the imidation reaction of the polyimide precursor at the time of layer formation. As the imidization accelerator, for example, an amine compound (more preferably an organic amine compound) is preferable.

An amine compound is a compound which amine-salts a polyimide precursor (its carboxy group) to increase its solubility in a solvent and functions as an imidization promoter. The amine compound is a non-surface-active amine compound having no surface activity. Specifically, the amine compound may be an amine compound having a molecular weight of 170 or less. The amine compound is preferably a compound other than a diamine compound which is a raw material of the polyimide precursor.
The amine compound is preferably a water-soluble compound. Here, water solubility means that at 25 ° C., the target substance dissolves in water at 1% by mass or more.

As an amine compound, a primary amine compound, a secondary amine compound, and a tertiary amine compound are mentioned.
Among these, as the amine compound, at least one selected from secondary amine compounds and tertiary amine compounds (in particular, tertiary amine compounds) is preferable. When a tertiary amine compound or a secondary amine compound is applied as an amine compound (in particular, a tertiary amine compound), the solubility of the polyimide precursor in the solvent is enhanced, and the storage stability of the polyimide precursor composition is easily improved. .

  Moreover, as an amine compound, the bivalent or more polyvalent amine compound is also mentioned other than a monovalent amine compound. When a polyvalent amine compound having two or more valences is applied, a pseudo crosslinked structure is easily formed between molecules of the polyimide precursor, and the storage stability of the polyimide precursor composition is easily improved.

Examples of primary amine compounds include methylamine, ethylamine, n-propylamine, isopropylamine, 2-ethanolamine, 2-amino-2-methyl-1-propanol, and the like.
Examples of secondary amine compounds include dimethylamine, 2- (methylamino) ethanol, 2- (ethylamino) ethanol, morpholine and the like.
Examples of tertiary amine compounds include 2-dimethylaminoethanol, 2-diethylaminoethanol, 2-dimethylaminopropanol, triethylamine, picoline, methylmorpholine, ethylmorpholine and the like.

  Here, as the amine compound, an amine compound having a nitrogen-containing heterocyclic structure (in particular, a tertiary amine compound) is also preferable from the viewpoint of storage stability. Examples of amine compounds having a nitrogen-containing heterocyclic structure include isoquinolines (amine compounds having an isoquinoline skeleton), pyridines (amine compounds having a pyridine skeleton), pyrimidines (amine compounds having a pyrimidine skeleton), and pyrazines. (Amine compounds having a pyrazine skeleton), piperazines (amine compounds having a piperazine skeleton), triazines (amine compounds having a triazine skeleton), imidazoles (amine compounds having an imidazole skeleton), polyaniline, polypyridine, polyamine and the like It can be mentioned.

  The amine compound is also preferably at least one selected from the group consisting of morpholines, amino alcohols and imidazoles from the viewpoint of storage stability, and N-methyl morpholine, N-ethyl morpholine and dimethylamino More preferably, it is at least one selected from the group consisting of ethanol.

  Among these, as the amine compound, a compound having a boiling point of 60 ° C. or more (preferably 60 ° C. or more and 200 ° C. or less, more preferably 70 ° C. or more and 150 ° C. or less) is preferable. When the boiling point of the amine compound is 60 ° C. or more, volatilization of the amine compound from the polyimide precursor composition during storage is suppressed, and the decrease in the solubility of the polyimide precursor in the solvent is easily suppressed.

  The content of the amine compound is 30 mol% or more and 200 mol% or less (preferably 50 mol% or more and 150 mol% or less, more preferably) with respect to the carboxy group (-COOH) of the polyimide precursor in the polyimide precursor solution. It is preferable that it is 80 mol% or more and 120 mol% or less. When the content of the amine compound is 50 mol% or more, the polyimide precursor is easily dissolved in the aqueous solvent. When the content of the amine compound is 200 mol% or less, the solution stability of the amine compound is easily secured, and the unpleasant odor is also easily suppressed.

  The amine compounds may be used alone or in combination of two or more.

-Hydrophilic solvent The polyimide resin layer is formed by applying a polyimide precursor solution, so the solvent used in this solution may be contained (remaining) as a residual solvent in the layer.
In addition, it is preferable that the solvent contained as a residual solvent is a hydrophilic solvent, and the above-mentioned hydrophilic solvent is specifically mentioned.

Conductive Agent In the case where the resin film according to the present embodiment is required for conductivity (for example, a transfer belt used for a transfer device), the polyimide resin layer may contain a conductive agent.

The conductive agent may be conductive (for example, volume resistivity less than 10 ⁷ Ω · cm, the same applies hereinafter) or semiconductive (for example, volume resistivity 10 ⁷ Ω · cm or more and 10 ¹³ Ω · cm or less, or the like) And particles of.
As the conductive agent, particles having a primary particle size of less than 10 μm are preferable, and particles having a primary particle size of 1 μm or less are more preferable.

The conductive agent is not particularly limited, but, for example, carbon black (for example, ketjen black, acetylene black, carbon black whose surface has been oxidized, etc.), carbon fiber, carbon nanotube, carbon-based material such as carbon nanotube, metal or Alloys (eg, aluminum, nickel, copper, silver etc.), metal oxides (eg, yttrium oxide, tin oxide, indium oxide, antimony oxide, SnO ₂ -In ₂ O ₃ complex oxide etc.), ion conductive substances (eg titanium) Acid potassium, LiCl, etc.).

  The conductive agent is selected according to the purpose of use, but carbon black is preferable, and in particular, pH 5 or less (preferably pH 4) from the viewpoint of the stability of the electrical resistance over time and the electric field dependency to suppress the electric field concentration due to the transfer voltage. Oxidized carbon black (for example, carbon black obtained by giving a carboxyl group, a quinone group, a lactone group, a hydroxyl group etc. to the surface) is preferable.

The average primary particle diameter of carbon black is, for example, 10 nm or more and 50 nm or less, and more preferably 15 nm or more and 30 nm or less.
The average primary particle size of the conductive agent such as carbon black is measured by the following method. First, a measurement sample having a thickness of 100 nm is taken from the belt member to be measured by a microtome, and this measurement sample is observed by a TEM (transmission electron microscope). The diameter of a circle equal to the projected area of each of the 50 particles of the conductive agent is taken as the particle diameter, and the average value is taken as the average primary particle diameter.

Although the content of the conductive agent in the polyimide resin layer is selected depending on the target resistance, for example, 20 mass% or more and 35 mass% or less is preferable with respect to the total mass of the polyimide resin layer, and further 25 mass% or more 30 mass% or less is more preferable.
The conductive agent may be used alone or in combination of two or more.

-Other Additives As additives other than the conductive agent, for example, a dispersant for improving the dispersibility of the conductive agent (carbon black etc.), various fillers for giving various functions such as mechanical strength , Catalysts, leveling agents for improving film formation quality, and the like.

Thickness The thickness of the polyimide resin layer is, for example, preferably 20 μm to 1000 μm, more preferably 50 μm to 200 μm, and still more preferably 60 μm to 130 μm.
The thickness (average thickness) of the polyimide resin layer is measured using an eddy current film thickness meter ISOSCOPE MP30 manufactured by Fisher Instruments. In addition, four locations at equal intervals in the circumferential direction, that is, 12 locations in total, at three locations of 40 mm from the central portion in the axial direction (width direction) of the polyimide resin layer and the central portion side from both ends respectively Measure and make the average value the average thickness.

(Silicone rubber layer)
The silicone rubber is contained as a main component in the silicone rubber layer. In addition, being contained as a main component represents having occupied 50 mass% or more with respect to all the rubber components contained in a silicone rubber layer.

  The silicone rubber layer may contain other rubber components (for example, fluoro rubber). However, the content of silicone rubber is 50% by mass or more, preferably 80% by mass or more, and more preferably 95% by mass or more based on all resin components.

Examples of the silicone rubber include RTV (Room Temperature Vulcanizing) silicone rubber, HTV (High Temperature Vulcanizing) silicone rubber, liquid silicone rubber, etc. Specifically, polydimethyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl Silicone rubber, fluorosilicone rubber and the like can be mentioned.
Specific examples thereof include addition polymerization type two-component polydimethylsiloxanes and derivatives thereof, and photocurable acrylic-modified silicone rubber.

In the case where the resin film according to the present embodiment is required for conductivity (for example, a transfer belt used in a transfer device), the silicone rubber layer may contain a conductive agent.
Examples of the conductive agent include those listed in the section of the polyimide resin layer, and the preferable content thereof is also the same as that of the polyimide resin layer.

  The silicone rubber layer may contain various known additives. Additives include, for example, fillers, softeners (paraffins, etc.), processing aids (stearic acid, etc.), anti-aging agents (amines, etc.), vulcanizing agents (sulfur, metal oxides, peroxides, etc.) And functional fillers (eg, alumina).

The thickness of the silicone rubber layer is, for example, preferably 30 μm to 600 μm, and more preferably 100 μm to 500 μm.
The measurement of the thickness (average thickness) of the silicone rubber layer is performed by the same method as the polyimide resin layer.

(Mixed boundary layer)
At the boundary between the polyimide resin layer and the silicone rubber layer, there is a mixed boundary layer in which the polyimide resin and the silicone rubber are mixed.
The mixed boundary layer is a layer formed by applying and penetrating a silicone rubber solution to the surface of a polyimide precursor coating, or a layer formed by applying and penetrating a polyimide precursor solution to a surface of a silicone rubber coating. Is preferred. Accordingly, as various components contained in the mixed boundary layer, those described in the section of the polyimide resin layer and the section of the silicone rubber layer can be mentioned.

(Surface layer)
The resin film according to the present embodiment may further have a surface layer on the silicone rubber layer. The surface layer is preferably a layer having releasability.

  Examples of the surface layer include a layer containing a fluorine-containing resin (a fluorine-containing resin layer). As the fluorine-containing resin layer, for example, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-hexafluoro Propylene-vinylidene fluoride copolymer (THV), polyvinylidene fluoride (PVDF), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polychlorotrifluoride ethylene (PCTFE), polyvinyl fluoride (PVF), etc. Layer of

  Various well-known additives may be blended in the surface layer. Additives include, for example, conductive agents such as carbon black, softeners (paraffin-based oil etc.), processing aids (stearic acid etc.), anti-aging agents (amine-based compounds etc.), vulcanizing agents (sulfur, metal oxidation) Substances, peroxides, etc.).

  The method of forming the surface layer is not particularly limited. The surface layer may be formed by applying a coating solution for forming the surface layer on the silicone rubber layer, drying it, and if necessary baking it. In addition, a coating solution for forming a surface layer is applied to the surface of a cylindrical body, dried, and if necessary, fired to obtain a tube-shaped surface layer, and then this tube-shaped surface layer is a silicone rubber layer It may be coated on top.

  The thickness of the surface layer is, for example, preferably 5 μm to 50 μm, and more preferably 10 μm to 40 μm.

(Use of resin film)
The resin film according to the present embodiment is used, for example, as a film member in an image forming apparatus. Specifically, a belt member for a transfer device (for example, an intermediate transfer belt, a recording medium conveyance belt, a primary transfer belt, a secondary transfer belt, etc.), a belt member for a fixing device (for example, a heating belt, a pressure belt, etc.) Applies to
The resin film according to the present embodiment may be coated on a roll such as a metal roll or a resin roll and used as a roll member. That is, the invention is applied to a roll member for a transfer device (for example, an intermediate transfer roll, a recording medium conveyance roll, a primary transfer roll, a secondary transfer roll, etc.) and a roll member for a fixing device (for example, a heating roll, a pressure roll, etc.) It is also good.

  The transfer device including the resin film according to the present embodiment is a transfer device for transferring the toner image formed on the surface of the image carrier to the surface of the recording medium, and the resin film according to the present embodiment is an intermediate transfer belt. A belt member such as a recording medium transport belt, a primary transfer belt, a secondary transfer belt, or a roll member such as an intermediate transfer roll, a recording medium transport roll, a primary transfer roll, or a secondary transfer roll.

  A fixing device provided with a resin film according to the present embodiment is a fixing device that heats a toner image formed on a recording medium to fix the toner image on the recording medium, and heats the resin film according to the present embodiment. A belt, a belt member such as a pressure belt, or a roll member such as a heating roll or a pressure roll.

  Here, as an example of the application of the resin film according to the present embodiment, an example applied to a fixing device will be described using the drawings.

[Fixing device]
The fixing device according to this embodiment has various configurations. For example, the fixing device includes a first rotating body and a second rotating body disposed in contact with the outer surface of the first rotating body, and the toner image is on the surface There is a fixing device for fixing a toner image on a recording medium by causing the recording medium formed in the above to pass through the contact portion between the first rotating body and the second rotating body. The resin film according to the present embodiment is applied as at least one of the first rotating body and the second rotating body.

  Hereinafter, a fixing device including a heating belt and a pressure roll will be described as the first and second embodiments. And in 1st and 2nd embodiment, the resin film concerning this embodiment can be applied to any of a heating belt and a pressure roll.

  The fixing device according to the present embodiment is not limited to the first and second embodiments, and may be a fixing device provided with a heating roll or a heating belt and a pressure belt. And the resin film concerning this embodiment can be applied to any of a heating roll, a heating belt, and a pressure belt.

First Embodiment of Fixing Device
The fixing device according to the first embodiment will be described. FIG. 3 is a schematic view showing an example of the fixing device according to the first embodiment.

As shown in FIG. 3, the fixing device 60 according to the first embodiment, for example, includes a heating roller 61 (an example of a first rotating body) that is rotationally driven, and a pressure belt 62 (an example of a second rotating body). A pressing pad 64 (an example of a pressing member) for pressing the heating roller 61 via the pressing belt 62 is provided.
In the pressure pad 64, for example, the pressure belt 62 and the heating roller 61 may be relatively pressed. Therefore, the pressure belt 62 side may be pressed by the heating roller 61, and the heating roller 61 side may be pressed by the pressure belt 62.

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

  On the other hand, a temperature sensitive element 69 is disposed in contact with the surface of the heating roll 61, for example. 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 setting temperature (for example, 150 ° C.).

  The pressure belt 62 is rotatably supported, for example, by a pressure pad 64 disposed inside and a belt travel guide 63. Then, in the sandwiching region N (nip portion), the pressing pad 64 presses the heating roller 61 to be disposed.

The pressure pad 64 is disposed, for example, in a state where it is pressed against the heating roll 61 via the pressure belt 62 inside the pressure belt 62, and forms a pinching area N with the heating roll 61. There is.
The pressing pad 64 has, for example, a front pinching member 64a for securing a wide pinching area N at the inlet side of the pinching area N, and a peeling pinching member 64b for applying distortion to the heating roll 61. Are arranged at the exit side of the sandwiching area N.

In order to reduce the sliding resistance between the inner circumferential surface of the pressure belt 62 and the pressing pad 64, for example, sheet-like sliding on the surface of the front pinching member 64a and the peeling pinching member 64b in contact with the pressure belt 62. A member 68 is provided. The pressing pad 64 and the sliding member 68 are held by a holding member 65 made of metal.
The sliding member 68 is provided, for example, such that its sliding surface is in contact with the inner peripheral surface of the pressure belt 62, and participates in holding and supplying oil existing between the pressure belt 62 and the same. .

  For example, a belt travel guide 63 is attached to the holding member 65, and the pressure belt 62 is configured to rotate.

  For example, the heating roller 61 is rotated in the direction of arrow S by a drive motor (not shown), and the pressure belt 62 is rotated in the direction of arrow R opposite to the rotation direction of the heating roller 61 following this rotation. That is, for example, while the heating roller 61 rotates in the clockwise direction in FIG. 3, the pressure belt 62 rotates in the counterclockwise direction.

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

  In the fixing device 60 according to the first embodiment, for example, by the concave front pinching member 64a following the outer peripheral surface of the heating roll 61, the pinching area N is wider than the configuration without the front pinching member 64a. Secured.

  Further, in the fixing device 60 according to the first embodiment, for example, the distortion of the heating roller 61 in the exit region of the sandwiching region N is realized by arranging the peeling sandwiching member 64b by protruding to the outer peripheral surface of the heating roller 61. Is configured to be locally large.

  If the peeling sandwiching member 64b is arranged in this way, for example, the sheet K after fixing passes through the locally formed large distortion when passing through the peeling sandwiching area. But it is easy to peel off the heating roll 61.

  As an auxiliary | assistant means of peeling, the peeling member 70 is arrange | positioned by the downstream of the pinching area | region N of the heating roll 61, for example. For example, the peeling member 70 is held by the holding member 72 in a state in which the peeling claw 71 approaches the heating roll 61 in a direction (counter direction) opposite to the rotation direction of the heating roll 61.

Second Embodiment of Fixing Device
The fixing device according to the second embodiment will be described. FIG. 4 is a schematic view showing an example of the fixing device according to the second embodiment.

  The fixing device 80 according to the second embodiment, as shown in FIG. 4, for example, presses the fixing belt module 86 including the heating belt 84 (an example of the first rotating body) and the heating belt 84 (fixing belt module 86). And the pressure roll 88 (an example of a 2nd rotary body) arrange | positioned. Further, for example, a pinching area N (nip portion) where the heating belt 84 (fixing belt module 86) and the pressure roll 88 contact is formed. In the sandwiching area N, the sheet K (an example of the recording medium) is pressed and heated to fix the toner image.

The fixing belt module 86 has, for example, an endless heating belt 84 and a heating belt 84 wound on the pressure roll 88 side, and is rotationally driven by the rotational force of a motor (not shown) and the heating belt 84 is on its inner periphery. A heating press roll 89 pressing from the surface to the pressure roll 88 side, and a support roll 90 supporting the heating belt 84 from the inside at a position different from the heating press roll 89 are provided.
The fixing belt module 86 is, for example, a support roll 92 disposed on the outside of the heating belt 84 to define its circumferential path, and a posture correction roll 94 for correcting the posture of the heating belt 84 from the heating press roll 89 to the support roll 90. And a support roll 98 for applying tension from the inner peripheral surface to the heating belt 84 on the downstream side of the sandwiching area N where the heating belt 84 (fixing belt module 86) and the pressure roll 88 contact. ing.

The fixing belt module 86 is provided, for example, such that a sheet-like sliding member 82 is interposed between the heating belt 84 and the heating pressing roller 89.
The sliding member 82 is provided, for example, such that its sliding surface is in contact with the inner circumferential surface of the heating belt 84, and participates in the holding and supply of the oil present between the sliding belt 82 and the heating belt 84.
Here, the sliding member 82 is provided, for example, in a state where its both ends are supported by the supporting member 96.

  For example, a halogen heater 89A (an example of a heating unit) is provided inside the heating and pressing roll 89.

The support roll 90 is, for example, a cylindrical roll formed of aluminum, and a halogen heater 90A (an example of a heating means) is disposed inside, so as to heat the heating belt 84 from the inner peripheral surface side. It has become.
At both ends of the support roll 90, for example, spring members (not shown) for pressing the heating belt 84 outward are disposed.

The support roll 92 is, for example, a cylindrical roll formed of aluminum, and on the surface of the support roll 92, a release layer of fluorine resin having a thickness of 20 μm is formed.
The release layer of the support roll 92 is formed, for example, in order to prevent toner and paper dust from being deposited on the support roll 92 from the outer peripheral surface of the heating belt 84.
For example, a halogen heater 92A (an example of a heating unit) is disposed inside the support roll 92, and heats the heating belt 84 from the outer peripheral surface side.

  That is, for example, the heating belt 84 is configured to be heated by the heating and pressing roll 89, the support roll 90, and the support roll 92.

The posture correction roll 94 is, for example, a cylindrical roll formed of aluminum, and in the vicinity of the posture correction roll 94, an end position measurement mechanism (not shown) for measuring the end position of the heating belt 84 is disposed. ing.
The posture correction roll 94 is provided with, for example, an axial displacement mechanism (not shown) for displacing the contact position in the axial direction of the heating belt 84 according to the measurement result of the end position measuring mechanism. It is configured to control.

  On the other hand, the pressure roller 88 is rotatably supported, for example, and is pressed against a portion where the heating belt 84 is wound around the heating pressure roller 89 by urging means such as a spring (not shown). As a result, as the heating belt 84 (heating pressing roll 89) of the fixing belt module 86 rotates in the direction of arrow S, the pressure roll 88 follows the arrow R following the heating belt 84 (heating pressing roll 89). It is designed to rotate in the direction.

  Then, the sheet K having an unfixed toner image (not shown) is conveyed in the direction of arrow P and guided to the nipping area N of the fixing device 80, the toner image is generated by the pressure and heat acting on the nipping area N Is fixed to the sheet K.

  In addition, although the form which applied the halogen heater (halogen lamp) as an example of a heat source was demonstrated in the fixing device 80 which concerns on 2nd Embodiment, it is not restricted to this, Radiation lamp heating elements (a radiation (infrared rays (A heating element that emits light etc.), a resistance heating element (a heating element that generates joule heat by passing current through a resistor; for example, a ceramic substrate on which a film having resistance is formed and baked) Good.

[Image forming apparatus]
Next, an image forming apparatus according to the present embodiment will be described.
The image forming apparatus according to the present embodiment includes, for example, an image carrier, charging means for charging the surface of the image carrier, and electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier. Developing means for developing an 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, and toner image And fixing means for fixing the recording medium to the recording medium.
The resin film according to the present embodiment is applied as a film member for a transfer device, a film member for a fixing device, and the like.

Hereinafter, an image forming apparatus according to the present embodiment will be described with reference to the drawings.
FIG. 5 is a schematic configuration view showing the configuration of the image forming apparatus according to the present embodiment. The resin film according to the present embodiment is applied as an intermediate transfer belt, and the resin film according to the present embodiment as at least one of the heating roller (first rotating body) and the pressure belt (second rotating body) in the fixing device. Has been applied.

  The image forming apparatus 100 according to the present embodiment is, for example, an intermediate transfer type image forming apparatus generally called tandem type, as shown in FIG. 5, and a plurality of toner images of respective color components are formed by electrophotography. And a primary transfer portion 10 for sequentially transferring (primary transfer) each color component toner image formed by each of the image forming units 1Y, 1M, 1C and 1K and each of the image forming units 1Y, 1M, 1C and 1K onto the intermediate transfer belt 15 A secondary transfer unit 20 for collectively transferring (secondary transfer) the superimposed toner images transferred onto the intermediate transfer belt 15 onto a sheet K serving as a recording medium, and fixing the image transferred onto the sheet K onto the sheet K And a device 60. The image forming apparatus 100 also includes a control unit 40 that controls the operation of each device (each unit).

  The fixing device 60 is the fixing device 60 according to the first embodiment described above. The image forming apparatus 100 may be configured to include the fixing device 80 according to the second embodiment described above.

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

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

  In addition, a developing device 14 is provided around the photosensitive member 11, as an example of a developing unit, for storing each color component toner to visualize the electrostatic latent image on the photosensitive member 11 with the toner. A primary transfer roll 16 is provided to transfer the color component toner images formed thereon onto the intermediate transfer belt 15 at the primary transfer portion 10.

  Furthermore, a photosensitive body cleaner 17 is provided around the photosensitive body 11, from which residual toner on the photosensitive body 11 is removed, and the charger 12, the laser exposure unit 13, the developing unit 14, the primary transfer roll 16 and the photosensitive body cleaner Seventeen electrophotographic devices are sequentially disposed along the rotational direction of the photosensitive member 11. The image forming units 1Y, 1M, 1C, and 1K are arranged substantially linearly in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15. It is done.

The intermediate transfer belt 15, which is an intermediate transfer member, is formed to have a volume resistivity of, for example, 1 × 10 ⁶ Ωcm or more and 1 × 10 ¹⁴ Ωcm or less, and its thickness is, for example, about 0.1 mm. There is.

  The intermediate transfer belt 15 is cyclically driven (rotated) at various speeds in the direction B shown in FIG. 5 by various rolls. As the various rolls, a drive roll 31 driven by a motor (not shown) excellent in constant speed to rotate the intermediate transfer belt 15, and an intermediate transfer belt 15 extending substantially linearly along the arrangement direction of the respective photosensitive members 11 Support roller 32 that supports the belt, tension application roll 33 that functions as a correction roll that applies tension to the intermediate transfer belt 15 and prevents meandering of the intermediate transfer belt 15, back surface roll 25 provided in the secondary transfer portion 20, intermediate It has a cleaning back roll 34 provided in a cleaning section for scraping off residual toner on the transfer belt 15.

  The primary transfer portion 10 is composed of a primary transfer roll 16 disposed opposite to the photosensitive member 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 is disposed so as to be in pressure contact with the photosensitive member 11 with the intermediate transfer belt 15 interposed therebetween, and the primary transfer roll 16 further has a voltage (primary) opposite to the charging polarity (negative polarity) of the toner. Transfer bias is applied. As a result, the toner images on the respective photosensitive members 11 are electrostatically attracted to the intermediate transfer belt 15 sequentially, and a superimposed toner image is formed on the intermediate transfer belt 15.

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

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

On the other hand, the secondary transfer roll 22 is a cylindrical roll having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less. The secondary transfer roll 22 is press-contacted to the back roll 25 with the intermediate transfer belt 15 interposed therebetween, and the secondary transfer roll 22 is grounded to form a secondary transfer bias with the back roll 25. The toner image is secondarily transferred onto the sheet K conveyed to the transfer unit 20.

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt for removing the residual toner and paper powder on the intermediate transfer belt 15 after the secondary transfer and cleaning the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be freely attachable and detachable.

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

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

  Further, in the image forming apparatus according to the present embodiment, the sheet storage unit 50 for storing the sheet K and the sheet K stacked in the sheet storage unit 50 are taken out at a predetermined timing as the transport means for transporting the sheet K. Transport roller 52 for transporting the sheet K, the transport roll 52 for transporting the sheet K fed by the feed roll 51, the transport guide 53 for feeding the sheet K transported by the transport roll 52 to the secondary transfer unit 20, secondary transfer The conveyance belt 55 conveys the sheet K conveyed after being secondarily transferred by the roll 22 to the fixing device 60, and a fixing inlet guide 56 which guides the sheet K to the fixing device 60.

Next, a basic image forming process of the image forming apparatus according to the present embodiment will be described.
In the image forming apparatus according to the present embodiment, image data output from an image reading apparatus (not shown) or a personal computer (PC) (not shown) is subjected to image processing by an image processing apparatus (not shown), and then image forming unit 1Y. , 1M, 1C, and 1K perform an imaging operation.

  The image processing apparatus performs image processing such as shading correction, positional deviation correction, lightness / color space conversion, gamma correction, various types of image editing such as border deletion, color editing, movement editing etc. on the inputted reflectance data. Be done. The image data subjected to the image processing is converted into color material tone data of four colors of Y, M, C, and K, and is output to the laser exposure device 13.

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

  The toner images formed on the photosensitive members 11 of the image forming units 1Y, 1M, 1C, and 1K are transferred onto the intermediate transfer belt 15 at the primary transfer portion 10 where the respective photosensitive members 11 and the intermediate transfer belt 15 contact. Ru. More specifically, in the primary transfer portion 10, the primary transfer roller 16 applies a voltage (primary transfer bias) opposite to the charging polarity (minus polarity) of the toner to the base material of the intermediate transfer belt 15, thereby forming a toner image Are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

  After the toner image is sequentially primarily transferred to the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 is moved to convey the toner image to the secondary transfer portion 20. When the toner image is conveyed to the secondary transfer unit 20, the conveyance unit rotates the paper feed roll 51 in accordance with the timing at which the toner image is conveyed to the secondary transfer unit 20, and the paper storage unit 50 A size sheet K is supplied. The sheet K supplied by the sheet supply roll 51 is conveyed by the conveyance roll 52, passes through the conveyance guide 53, and reaches the secondary transfer unit 20. Before reaching the secondary transfer portion 20, the sheet K is temporarily stopped, and the sheet K is rotated by rotation of a positioning roll (not shown) in accordance with the movement timing of the intermediate transfer belt 15 holding the toner image. The position of the toner image and the position of the toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the sheet K conveyed at the same timing is nipped between the intermediate transfer belt 15 and the secondary transfer roll 22. At that time, when a voltage (secondary transfer bias) having the same polarity as the charging polarity (minus polarity) of the toner is applied from the feeding roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Be done. Then, the unfixed toner images held on the intermediate transfer belt 15 are collectively electrostatically transferred onto the sheet K at the secondary transfer portion 20 pressurized by the secondary transfer roll 22 and the back roll 25. Ru.

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

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

  As mentioned above, although this embodiment was described, it can not be interpreted limitedly to the said embodiment, and various modification, change, improvement are possible.

  Hereinafter, the present embodiment will be described in detail by way of examples, but the present embodiment is not limited to these examples.

Example 1
[Production of resin film]
-Formation process of polyimide precursor coating film-
A solution of triethylamine (imidization accelerator, manufactured by Daicel Corporation, trade name: triethylamine [TEA]) in a polyimide precursor N-methylpyrrolidone solution (made by Ube Industries, Ltd., trade name: U varnish S) The polyimide precursor solution (viscosity 120 Pa · s) was prepared by adding it to 3% by mass with respect to the total solid content in the solution.
This polyimide precursor solution was applied onto the surface of the aluminum plate subjected to release treatment by brushing and then brushing off. Subsequently, it was made to dry at 100 degreeC environment for 50 minutes, and the polyimide precursor coating film was obtained.
In addition, the content rate of the residual solvent (N- methyl pyrrolidone) in this polyimide precursor coating film was 45 mass%.

-Formation process of silicone rubber coating film-
85% by mass of a mixture obtained by mixing two-component sillycon gum solution (Shin-Etsu Chemical Co., Ltd., X-34 to 1972-3A and X-34 to 1972-3B) in a ratio of 1: 1, and 15% by mass of butyl acetate, A silicone rubber solution was prepared by The silicone rubber solution is applied onto the polyimide precursor coating film before imidization by a flow coating method (method after brushing and brushing) and then dried for 20 minutes in an environment of 100 ° C. to obtain a polyimide precursor. The laminated coating film in which the silicone rubber coating film was laminated on the coating film was obtained.

-Heating (baking) process-
Then, the laminated coating film was heated (baked) by heating for 120 minutes at a temperature of 220 ° C. only on the single side from the side of the aluminum plate (mold) (that is, the side of the polyimide precursor coating). The sheet-like resin film A1 was obtained by peeling from the aluminum plate (mold) after heating.

When the obtained resin film A1 was enlarged and observed by STEM or TEM, a clear boundary line was not observed at the boundary between the polyimide resin layer and the silicone rubber layer, and a region where the polyimide resin and the silicone rubber were mixed (Mixed boundary layer) was observed.
The thickness (average thickness) of the polyimide resin layer, the silicone rubber layer, and the mixed boundary layer is shown in Table 2.
The imidation ratio of the polyimide resin layer after the heating (baking) step is shown in Table 2.
Furthermore, the amount [A] of COOH groups in the polyimide precursor in the polyimide precursor solution, the amount [B] of COOH groups in the polyimide resin in the mixed boundary layer after the heating (baking) step, and the ratio [B / A] is shown in Table 2.

Example 2
Example 1 Example 1 except that triethylamine (imidization accelerator) was not added to the polyimide precursor solution, and the heating temperature in the heating (baking) step was changed to the temperature described in Table 1 below. A resin film was obtained in the same manner as in.

Comparative Example 1
-Formation process of polyimide precursor coating film-
In the same manner as in Example 1, a polyimide precursor coating was formed on the surface of an aluminum plate.

-First heating step (imidization)-
Next, heating was performed at a temperature of 400 ° C. for 120 minutes from the side of the aluminum plate (mold) to form a polyimide resin layer.

-Formation process of silicone rubber coating film-
A silicone rubber solution was prepared as in Example 1.
The silicone rubber solution is applied onto the polyimide resin layer after imidization by a flow coating method (method after brushing and brushing), and then dried for 20 minutes in an environment of 100 ° C. to form a polyimide resin layer. The laminated film on which the silicone rubber coating film was laminated was obtained.

-Second heating step (silicone rubber baking)-
Next, heating (baking) was performed at a temperature of 120 ° C. for 120 minutes only from the side of the aluminum plate (mold) (that is, the side of the polyimide precursor coating film) on one side. The sheet-like resin film B1 was obtained by peeling from an aluminum plate (mold) after heating.

  When the resin film B1 thus obtained was enlarged and observed by STEM or TEM, a clear boundary was observed at the boundary between the polyimide resin layer and the silicone rubber layer, and a region where the polyimide resin and the silicone rubber were mixed (mixed Boundary layer was not observed.

Comparative Example 2
In Comparative Example 1, except that triethylamine (imidization accelerator) was not added to the polyimide precursor solution, and the surface of the polyimide resin layer before application of the silicone rubber solution after imidization was subjected to ozone treatment shown below A resin film was obtained in the same manner as in Comparative Example 1.
-Ozone treatment method-
An ozone treatment surface was obtained by injecting high concentration dissolved ozone for 30 minutes with an ozone treatment apparatus of OM Industry Co., Ltd.

Comparative Example 3
In Comparative Example 1, except that triethylamine (imidization accelerator) was not added to the polyimide precursor solution, and the surface of the polyimide resin layer before application of the silicone rubber solution after imidization was subjected to the alkali treatment shown below A resin film was obtained in the same manner as in Comparative Example 1.
-Alkaline treatment method-
The substrate was immersed in a 50 g / dm ³ high concentration aqueous NaOH solution heated to 65 ° C. for 2 minutes to obtain an alkali-treated surface.

Comparative Example 4
In Comparative Example 1, no triethylamine (imidization accelerator) was added to the polyimide precursor solution, and after imidization, a primer (Shin-Etsu Chemical Co., Ltd., trade name) was applied to the surface of the polyimide resin layer before applying the silicone rubber solution. A resin film was obtained in the same manner as in Comparative Example 1 except that a primer layer was provided by applying X-33-156-20).

〔Evaluation test〕
High-Temperature High-Humidity T-Peeling Test First, the resin films obtained in the respective examples and comparative examples were allowed to stand for 24 hours in a steam oven at 50 ° C. and 85% high-temperature high-humidity environment. Next, a T-peel test was performed on the resin film after standing in a high temperature and high humidity environment using a tensile tester.
In the case of cohesive peeling (in which the peeling was generated throughout the resin film without being limited to the boundary between the polyimide resin layer and the silicone resin layer) was regarded as “A (○)” evaluation, and interfacial peeling (polyimide resin layer and silicone resin layer The case where exfoliation occurred at the boundary with and was made "B (x)" evaluation.

Evaluation of Thermal Deterioration of Silicone Rubber Layer The silicone rubber layer after the heating (baking) step or after the second heating step was peeled off from the polyimide resin layer with a knife, and the viscoelasticity was measured. Specifically, the storage elastic modulus was measured at 150 ° C. in accordance with JIS K7244-4 using a dynamic viscoelasticity tester (manufactured by A & D Co., Ltd., DDV-01FP). .
Based on Example 1, those in which a decrease in storage elastic modulus was not observed were regarded as “A (○)” evaluation, and those in which a decrease in storage elastic modulus was observed were regarded as “B (×)” evaluation.

  From the above results, it is understood that the resin film of this example is excellent in the adhesion between the polyimide resin layer and the silicone rubber layer, as compared with the resin film of the comparative example.

10, 110 resin film 10A, 110A polyimide resin layer 10B, 110B silicone rubber layer 10M mixed boundary layer 62 pressure belt 63 belt travel guide 64 pressing pad 64a front sandwiching member 64b peeling sandwiching member 65 holding member 66 halogen lamp 68 slide Moving member 69 Temperature-sensitive element 70 Peeling member 71 Peeling claw 72 Holding member 80 Fixing device 82 Sliding member 84 Heating belt 86 Fixing belt module 88 Pressure roll 89A Halogen heater 89 Heating pressure roll 90A Halogen heater 90 Support roll 92A Halogen heater 92 Support roll 94 Posture correction roll 96 Support member 98 Support roll 100 Image forming apparatus 110C Surface layer

Claims (19)

Polyimide resin layer,
A silicone rubber layer provided on the polyimide resin layer;
A mixed boundary layer which exists at the boundary between the polyimide resin layer and the silicone rubber layer and in which the polyimide resin and the silicone rubber are mixed;
And a resin film for an image forming apparatus.   The resin film according to claim 1, wherein an average thickness of the mixed boundary layer is 50 nm or more and 500 nm or less.   The resin film according to claim 1 or 2 whose imidation ratio of said polyimide resin layer is 80% or more and 100% or less.   The resin film according to any one of claims 1 to 3, wherein the polyimide resin layer contains an imidization accelerator.   The resin film according to claim 4, wherein the imidization accelerator is an amine compound.   The resin film according to any one of claims 1 to 5, wherein the polyimide resin layer contains a hydrophilic solvent.   The resin film according to claim 6, wherein the hydrophilic solvent is an aprotic polar solvent.   The resin film according to any one of claims 1 to 7, further comprising a layer containing a fluorine-containing resin on the silicone rubber layer.   The shape of the said resin film is an endless belt shape, The resin film of any one of Claims 1-8. It has an endless belt-like resin film according to claim 9,
A transfer device for transferring a toner image formed on the surface of an image carrier to the surface of a recording medium. An image carrier,
An image carrier toner image forming means for forming a toner image on the surface of the image carrier;
A transfer unit, comprising: the transfer device according to claim 10, for transferring the toner image to a surface of a recording medium;
An image forming apparatus comprising: It has an endless belt-like resin film according to claim 9,
A fixing device for heating and fixing a toner image formed on a recording medium to the recording medium. Recording medium toner image forming means for forming a toner image on the recording medium;
A fixing unit comprising the fixing device according to claim 12 and fixing the toner image to the recording medium.
An image forming apparatus comprising: Applying a polyimide precursor solution and drying to form a polyimide precursor coating film;
Applying a silicone rubber solution onto the polyimide precursor coating film and drying to form a laminated coating film in which the silicone rubber coating film is laminated on the polyimide precursor coating film;
A heating step of heating the laminated coating film to imidize a polyimide precursor in the polyimide precursor coating film and baking a silicone rubber in the silicone rubber coating film;
The manufacturing method of the resin film which obtains the resin film of any one of Claims 1-9 which has the said mixed boundary layer through.   The method for producing a resin film according to claim 14, wherein the solvent content of the polyimide precursor coating film is 35% by mass or more and 65% by mass or less when the silicone rubber solution is applied.   The method for producing a resin film according to claim 14 or 15, wherein the heating temperature in the heating step is 150 ° C or more and 330 ° C or less.   The method for producing a resin film according to any one of claims 14 to 16, wherein the polyimide precursor solution contains an imidization accelerator.   The method for producing a resin film according to claim 17, wherein the imidization accelerator is an amine compound.   The ratio [B / A] of the amount [A] of COOH group in the polyimide precursor in the polyimide precursor solution and the amount [B] of COOH group in the polyimide resin in the mixed boundary layer after the heating step is The method for producing a resin film according to any one of claims 14 to 18, which is 1/100 or more and 1/2 or less.