JP2018151473A - Fixing member, fixing apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing member configured to reduce a difference in glossiness of a fixation image between an area corresponding to an axial central part of the fixing member and areas corresponding to both axial ends of the fixing member.SOLUTION: A fixing member 62A includes: a cylindrical base material 110A; an elastic layer 110B arranged on an outer peripheral surface of the base material 110A and including silicone rubber having a carbon-carbon double bond; and a lower adhesion layer 112 arranged in contact with the elastic layer 110B between the base material 110A and the elastic layer 110B and formed by curing a composition containing polysiloxane having a SiH structure. The elastic layer 110B and the lower adhesion layer 112 are formed so that a thickness is increased from an axial central part 62C in the base material 110A toward axial ends 62S.SELECTED DRAWING: Figure 2

Description

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

  In an image forming apparatus such as a copying machine or a printer using an electrophotographic method, for example, a drum-shaped photoconductor is charged, and the photoconductor is exposed to light controlled based on image information to electrostatically form the photoconductor. A latent image is formed, and the electrostatic latent image is converted into a visible image (toner image) with toner. After the toner image is transferred from the photosensitive member to a recording medium such as paper, it is fixed on the recording medium by a fixing device. Thus, an image is formed.

  The fixing device includes, for example, a pressure member that rotates and a belt member that rotates in contact with the pressure member, and presses the belt member from the inner peripheral surface toward the pressure member to apply pressure to the belt member. A fixing member that fixes a toner image on the recording medium by passing the recording medium through the contact portion. Are known.

  For example, Patent Document 1 discloses a base, an addition reaction type silicone rubber layer having a specific JIS A hardness and a specific thickness provided on the base, and an addition reaction type silicone rubber system covering the silicone rubber layer. It has a tube-shaped fluororesin layer provided as the outermost layer through an adhesive layer, and the silicone rubber layer identifies organopolysiloxanes having active hydrogen bonded to silicon and organopolysiloxanes having unsaturated aliphatic groups. The fixing member formed by making it react by this ratio is disclosed.

  Patent Document 2 discloses a toner fixing member having an elastic layer made of an addition reaction type silicone rubber having a thickness of 200 μm or more and an outermost layer made of a fluororesin having a thickness of 30 μm or less, and this silicone rubber. Is composed of silicone rubber obtained by curing a silicone material of less than 1.0 in the ratio (H / Vi) of the number of moles of hydrogen atoms of the siloxane bond to the number of moles of vinyl groups of the siloxane bond in the silicone rubber material before curing. In the toner fixing member to be used, in the thickness range of at least 10 to 100 μm from the outermost layer side of the silicone rubber, a crosslinking corresponding to a silicone rubber obtained by curing a material in which H / Vi of the silicone rubber material is blended to 1.0 or more. A toner fixing member characterized by having a degree is disclosed.

  Further, in Patent Document 3, a dispersion of an addition reaction catalyst is applied on a substrate whose surface has been previously primed, and further, an organopolysiloxane having a vinyl group and silicon-bonded hydrogen atoms are further applied on the coated surface. A rubber roller characterized in that an addition-reactive silicone rubber material containing a hydrogenorganopolysiloxane having an adhesive property is applied, and the addition-reactive silicone rubber material is heat-cured to bond and integrally form a base material and silicone rubber A manufacturing method is disclosed.

JP 2006-030801 A JP 2004-133286 A JP 2002-194103 A

As a fixing member having a cylindrical base material and an elastic layer, an axial direction of the base material (hereinafter, simply referred to as “axial direction”) is used to suppress wrinkling of the recording medium when fixing an image. And an elastic layer provided so that the thickness increases from the central portion toward both axial end portions. Hereinafter, a shape in which the thickness increases from the axial center to both ends is also referred to as a “flare shape”.
In addition, for the purpose of improving the adhesion between the base material and the elastic layer, an adhesive which is a cured product of a composition containing a polysiloxane having a SiH structure, using an elastic layer containing a silicone rubber having a carbon-carbon double bond A layer may be provided between the substrate and the elastic layer. Hereinafter, a silicone rubber having a carbon-carbon double bond is also referred to as “specific silicone rubber”, and an adhesive layer that is a cured product of a composition containing polysiloxane having a SiH structure is also referred to as “specific adhesive layer”.

  However, when a flare-shaped elastic layer containing specific silicone rubber is applied and a specific adhesive layer is provided between the base material and the elastic layer so as to be in contact with the elastic layer, the glossiness of the obtained fixed image is reduced. Unevenness may occur. Specifically, a fixed image may be obtained in which the glossiness of the region corresponding to the central portion in the axial direction is lower than the glossiness of the region corresponding to both end portions in the axial direction.

  An object of the present invention is to provide a cylindrical base material, a flare-shaped elastic layer containing specific silicone rubber, and a specific adhesion that is provided in contact with the elastic layer between the base material and the elastic layer and does not change in thickness in the axial direction. And a fixing member in which the difference between the region corresponding to the central portion in the axial direction of the fixing member and the region corresponding to both axial end portions of the fixing member in the glossiness of the fixed image is suppressed as compared with the case of having a layer. It is in.

The above problem is solved by the following means. That is,
The invention according to claim 1
A cylindrical substrate;
An elastic layer that is disposed on the outer peripheral surface of the substrate and includes silicone rubber having a carbon-carbon double bond;
A lower adhesive layer, which is a cured product of a composition comprising polysiloxane having a SiH structure, disposed between and in contact with the elastic layer between the base material and the elastic layer;
Have
The elastic layer and the lower adhesive layer are fixing members that increase in thickness from an axial center portion to both end portions of the base material.

The invention according to claim 2
The fixing member according to claim 1, wherein a storage elastic modulus of the elastic layer in the central portion in the axial direction is lower than a storage elastic modulus of the elastic layer in both end portions in the axial direction.

The invention according to claim 3
The thickness of the lower adhesive layer in the central portion in the axial direction is Tp ₁ c, the thickness of the lower adhesive layer in both end portions in the axial direction is Tp ₁ s, and the thickness of the elastic layer in the central portion in the axial direction. the Tec, when the thickness of the elastic layer in both end portions of the axial and _Tes, according to claim 1 or claim 2 satisfying the relation of _{(Tp 1 c / Tp 1 s} ) <(Tec / Tes) Fixing member.

The invention according to claim 4
The fixing member according to claim 1, further comprising a surface layer on an outer peripheral surface of the elastic layer.

The invention according to claim 5
A cured product of a composition comprising polysiloxane having a SiH structure, disposed between the elastic layer and the surface layer, in contact with the elastic layer, and having a thickness from the central portion in the axial direction toward both ends. The fixing member according to claim 4, further comprising an upper adhesive layer increasing.

The invention according to claim 6
The thickness of the upper adhesive layer at the central portion in the axial direction is Tp ₂ c, the thickness of the upper adhesive layer at both axial end portions is Tp ₂ s, and the thickness of the elastic layer at the central portion in the axial direction is Tec. The fixing member according to claim 5, wherein the relationship of (Tp ₂ c / Tp ₂ s) <(Tec / Tes) is satisfied, where Tes is the thickness of the elastic layer at both ends in the axial direction.

The invention according to claim 7 provides:
A first rotating body;
A second rotating body that pressurizes an outer peripheral surface of the first rotating body and sandwiches a recording medium having an unfixed toner image formed on the surface together with the first rotating body;
Have
The fixing device according to claim 1, wherein at least one of the first rotating body and the second rotating body is the fixing member according to claim 1.

The invention according to claim 8 provides:
An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
A fixing unit comprising the fixing device according to claim 7 and fixing the toner image on the recording medium;
An image forming apparatus comprising:

  According to the first aspect of the present invention, the cylindrical base material, the flare-shaped elastic layer containing the specific silicone rubber, and the elastic layer between the base material and the elastic layer are provided in contact with the elastic layer and have a thickness in the axial direction. Compared to the case of having a specific adhesive layer that does not change, the difference between the glossiness of the region corresponding to the central portion of the fixing member in the axial direction and the glossiness of the region corresponding to both axial ends of the fixing member in the fixed image is suppressed. A fixing member is provided.

  According to the second aspect of the present invention, the axial direction of the fixing member in the glossiness of the fixed image is compared with the case where the storage elastic modulus of the elastic layer at the axial center is the same as the storage elastic modulus of the elastic layer at both axial ends. There is provided a fixing member in which a difference between a region corresponding to the central portion and a region corresponding to both end portions in the axial direction of the fixing member is suppressed.

According to the third aspect of the present invention, compared to the case where the relationship of (Tp ₁ c / Tp ₁ s) ≧ (Tec / Tes) is satisfied, the region corresponding to the axial central portion of the fixing member in the glossiness of the fixed image And a fixing member that suppresses the difference between the regions corresponding to both axial ends of the fixing member.

  According to the invention of claim 4, a base material provided in contact with the elastic layer between the cylindrical base material, the flare-shaped elastic layer containing the specific silicone rubber, the surface layer, and the base material and the elastic layer. Compared to the case of having a specific adhesive layer whose thickness does not change in the axial direction of the material, a region corresponding to the central portion of the fixing member in the axial direction and a region corresponding to both axial ends of the fixing member in the glossiness of the fixed image A fixing member that suppresses the difference is provided.

  According to the fifth aspect of the present invention, compared to the case where the thickness of the upper adhesive layer does not change in the axial direction of the base material, the fixing member and the region corresponding to the axial central portion of the fixing member in the glossiness of the fixed image There is provided a fixing member that suppresses a difference from a region corresponding to both end portions in the axial direction.

According to the sixth aspect of the present invention, compared to the case where the relationship of (Tp ₂ c / Tp ₂ s) ≧ (Tec / Tes) is satisfied, the region corresponding to the axial central portion of the fixing member in the glossiness of the fixed image And a fixing member that suppresses the difference between the regions corresponding to both axial ends of the fixing member.

  According to the invention which concerns on Claim 7 or 8, it is provided in contact with an elastic layer between a cylindrical base material, a flare-shaped elastic layer containing specific silicone rubber, and a base material and an elastic layer. Compared to the case where a fixing member having a specific adhesive layer whose thickness does not change in the axial direction is applied, the area corresponding to the central portion of the fixing member in the axial direction and the both ends in the axial direction of the fixing member in the glossiness of the fixed image There is provided a fixing device or an image forming apparatus in which a difference from an area to be suppressed is suppressed.

FIG. 4 is a schematic diagram of a cross section perpendicular to the axial direction in an example of a fixing member according to the exemplary embodiment. It is a schematic diagram of a cross section along the axial direction in an example of a fixing member according to the present embodiment. FIG. 6 is a schematic diagram in which a part of a cross section along the axial direction in an example of a fixing member according to the present embodiment is enlarged. It is a schematic diagram of a cross section perpendicular to the axial direction in another example of the fixing member according to the present embodiment. FIG. 10 is a schematic diagram enlarging a part of a cross section along the axial direction in another example of the fixing member according to the present embodiment. 1 is a schematic configuration diagram illustrating an example of a fixing device according to an exemplary embodiment. FIG. 7 is a schematic configuration diagram of the fixing device illustrated in FIG. 6 as viewed from the conveyance direction of the recording medium. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment. It is a graph which shows the result of having measured the storage elastic modulus in each position in an axial direction about the fixing member of an example. FIG. 6 is a schematic diagram in which a part of a cross section along the axial direction in an example of a fixing member of a comparative example is enlarged.

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

[Fixing member]
The fixing member according to the present embodiment is disposed in contact with the elastic layer between a cylindrical base material, an elastic layer disposed on an outer peripheral surface of the base material, and the base material and the elastic layer. And a lower adhesive layer.
The elastic layer includes a silicone rubber having a carbon-carbon double bond (that is, a specific silicone rubber), and the thickness increases from the central portion in the axial direction of the substrate toward both ends (that is, the flare-shaped elastic layer). Is).
Further, the lower adhesive layer is a layer of a cured product of the composition containing polysiloxane having a SiH structure (that is, a specific adhesive layer), and the thickness increases from the axial center to both ends of the substrate. (Ie, a flare-shaped adhesive layer).

Here, the “axial direction” refers to a direction orthogonal to the circumferential direction of the cylindrical base material. For example, when the base material is an endless belt-like member, it refers to the axial direction of the cylinder (that is, the belt width direction) when the endless belt-like member is kept in a cylindrical shape.
The central portion in the axial direction refers to the center in the axial direction of the region where the base material, the lower adhesive layer, and the elastic layer are laminated (positions that are equidistant from both ends). The position of 20 mm is said from the both ends of the area | region where the material, the lower side adhesive layer, and the elastic layer were laminated | stacked toward the center.
The “SiH structure” refers to a chemical structure in which a silicon atom and a hydrogen atom are directly bonded.

First, the configuration of the fixing member according to the present embodiment will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a cross section perpendicular to the axial direction in an example of the fixing member according to the present embodiment, and FIG. 2 is a schematic diagram showing a cross section along the axial direction of the fixing member shown in FIG. FIG. 3 is an enlarged schematic view of region A in FIG.
4 is a schematic diagram showing a cross section perpendicular to the axial direction in another example of the fixing member according to the present embodiment, and FIG. 5 is a cross section of the fixing member shown in FIG. 4 along the axial direction. It is the schematic diagram which expanded the part (specifically area | region corresponded to the area | region A of FIG. 2).
Here, in FIG.3 and FIG.5, the broken line C shows the position relatively near the axial direction center part 62C, and the broken line S shows the position near the axial direction edge part 62S relatively.
In addition, the same code | symbol is provided to the member which has the substantially same function throughout all the drawings, and the overlapping description may be abbreviate | omitted suitably.

The fixing member 62A shown in FIGS. 1 to 3 includes a base material 110A, a lower adhesive layer 112 provided on the base material 110A, an elastic layer 110B provided in contact with the lower adhesive layer 112, and an elastic property. And a surface layer 110C provided without an adhesive layer on the layer 110B. The elastic layer 110B includes a specific silicone rubber, and the lower adhesive layer 112 is a specific adhesive layer. As shown in FIGS. 2 and 3, both the elastic layer 110B and the lower adhesive layer 112 have a flare shape in which the thickness increases from the axial center portion 62C toward the axial end portions 62S on both sides. Yes.
Note that the surface layer 110C is a layer provided as necessary, and the fixing member of the present embodiment may have a form without the surface layer 110C.

4 to 5, the fixing member 62B includes a base 110A, a lower adhesive layer 112 provided on the base 110A, an elastic layer 110B provided in contact with the lower adhesive layer 112, The upper adhesive layer 114 provided in contact with the elastic layer 110B and the surface layer 110C provided on the upper adhesive layer 114 are provided. The elastic layer 110B includes specific silicone rubber, and both the lower adhesive layer 112 and the upper adhesive layer 114 are specific adhesive layers. Further, as shown in FIG. 5, in any of the elastic layer 110B, the lower adhesive layer 112, and the upper adhesive layer 114, a flare shape in which the thickness increases from the axial center portion 62C toward the axial end portions 62S on both sides. It has become.
Note that the upper adhesive layer 114 and the surface layer 110C are layers provided as necessary, and the fixing member of the present embodiment may not include the upper adhesive layer 114 and the surface layer 110C, and may not include the adhesive layer. The surface layer 110C may be provided. In addition, the fixing member of the present embodiment may be provided with an adhesive layer other than the specific adhesive layer instead of the upper adhesive layer 114. The fixing member is not a flare shape, and the thickness increases from the axial center portion 62C to the axial end portion 62S. A non-adhesive layer (for example, the thickness does not change in the axial direction) may be provided.

  In both the fixing member 62A and the fixing member 62B shown in FIGS. 1 to 5, both the elastic layer 110B including the specific silicone rubber and the lower adhesive layer 112 which is the specific adhesive layer have a flare shape. For this reason, in the fixed image, the difference between the glossiness of the region corresponding to the axial central portion 62C of the fixing member 62A or the fixing member 62B and the glossiness of the region corresponding to the axial end portion 62S is suppressed. The reason is guessed as follows.

  First, as a method for suppressing wrinkles of a recording medium that occurs when an image is fixed using a fixing member having a cylindrical base material and an elastic layer, the outer diameters at both ends in the axial direction compared to the central portion in the axial direction. The method of enlarging is mentioned. As a method for increasing the outer diameter of the fixing member from the axial center to both ends in the axial direction, for example, the elastic layer has a flare shape (that is, a shape in which the thickness increases from the axial center to both ends). The method to do is mentioned. In this way, the flare-shaped elastic layer is used, and the outer diameter of the fixing member is made larger at both axial end portions than at the axial central portion, thereby suppressing wrinkles of the recording medium.

Moreover, as a method for improving the adhesion between the base material and the elastic layer, a method using a specific adhesive layer (that is, an adhesive layer that is a cured product of a composition containing polysiloxane having a SiH structure) can be used.
Specifically, an elastic layer containing a specific silicone rubber (that is, a silicone rubber having a carbon-carbon double bond) is used, and the specific adhesive layer is elastic as a lower adhesive layer between the base material and the elastic layer. Provided in contact with the layer. In the process of manufacturing the fixing member in which the elastic layer containing the specific silicone rubber is in contact with the specific adhesive layer, a layer that becomes an elastic layer by curing (hereinafter also referred to as “pre-curing elastic layer”) and a layer that becomes the specific adhesive layer by curing ( Hereinafter, it is heated in a state of being in contact with the “adhesive layer before curing”. In the heating process, the carbon-carbon double bond of the uncured silicone rubber contained in the pre-curing elastic layer reacts with the SiH structure of the polysiloxane contained in the pre-curing adhesive layer to form a covalent bond. Is done. It is thought that the covalent bond contributes to high adhesiveness and improves the adhesiveness between the base material and the elastic layer.
The pre-curing elastic layer and the pre-curing adhesive layer are not limited to uncured ones, but include semi-cured ones (middle stages of curing).

Combining these technologies, using a flare-shaped elastic layer containing specific silicone rubber, and providing a specific adhesive layer between the base material and the elastic layer, while suppressing wrinkles of the recording medium, It is thought that the adhesion with the layer is improved.
However, when a flare-shaped elastic layer containing specific silicone rubber and a specific adhesive layer in contact with the elastic layer are applied, in the glossiness of the fixed image, the region corresponding to the axial center of the fixing member and both axial ends of the fixing member A difference may occur between the region corresponding to the part.
Hereinafter, the reason why a difference in glossiness occurs in a fixed image will be described with reference to the drawings.

FIG. 10 is an enlarged view of a part of a cross section cut along the axial direction in an example of a conventional fixing member in which a flare-shaped elastic layer containing specific silicone rubber and a specific adhesive layer are provided in direct contact with each other. The schematic diagram shown is shown. In FIG. 10, the broken line C is a position relatively close to the central portion in the axial direction, and the broken line S is a position relatively close to the end portion in the axial direction.
The fixing member 262 shown in FIG. 10 includes a base 210A, a lower adhesive layer 212 provided on the base 210A, an elastic layer 210B provided in contact with the lower adhesive layer 212, and an elastic layer 210B. And a surface layer 210 </ b> C provided thereon. The elastic layer 210B includes a specific silicone rubber, and the lower adhesive layer 212 is a specific adhesive layer. Of the layers constituting the fixing member 262, only the elastic layer 210B has a flare shape, and the other layers (that is, the base material 210A, the lower adhesive layer 212, and the surface layer 210C) are all in the axial direction. The shape does not change in thickness.

As described above, when an image is fixed using the fixing member 262, the difference between the glossiness of the region corresponding to the central portion in the axial direction of the fixing member 262 and the glossiness of the region corresponding to both end portions in the axial direction in the fixed image. May occur. Specifically, the glossiness of the area corresponding to the central portion in the axial direction of the fixing member 262 is lower than the glossiness of the area corresponding to both axial end portions.
The decrease in glossiness in the region corresponding to the axial central portion is presumed to be caused by the fact that the hardness of the axial central portion on the outer peripheral surface of the fixing member 262 is higher than both axial end portions. Is done.

The reason why the hardness of the central portion in the axial direction on the outer peripheral surface of the fixing member 262 is high is estimated as follows.
As described above, in the fixing member 262 in which the elastic layer 210B including the specific silicone rubber and the lower adhesive layer 212 which is the specific adhesive layer are in contact with each other, the pre-curing elastic layer and the pre-curing adhesive layer are manufactured in the process of manufacturing the fixing member 262. It is heated in the state where it touches. In the heating step, at the interface between the pre-curing elastic layer and the pre-curing adhesive layer, an uncured carbon-carbon double bond of the silicone rubber contained in the pre-curing elastic layer and the polysiloxane contained in the pre-curing adhesive layer And a SiH structure react to form a covalent bond.
However, part of the polysiloxane contained in the pre-curing adhesive layer may penetrate not only to the interface between the pre-curing elastic layer and the pre-curing adhesive layer but also to the inside of the pre-curing elastic layer. When the SiH structure of the polysiloxane migrated to the inside of the pre-curing elastic layer reacts with the carbon-carbon double bond of the uncured silicone rubber in the inside of the pre-curing elastic layer, a new reaction occurs in the inside of the pre-curing elastic layer. A covalent bond is formed, and the storage elastic modulus of the pre-curing elastic layer is increased. This increase in storage elastic modulus is considered to occur more easily as the pre-curing adhesive layer is thicker (that is, the amount of the composition containing polysiloxane having a SiH structure is larger) and the pre-curing elastic layer is thinner. That is, it is considered that the storage elastic modulus of the elastic layer 210B is likely to increase as the lower adhesive layer 212 is thicker, and the storage elastic modulus of the elastic layer 210B is likely to increase as the elastic layer 210B is thinner.

Accordingly, in FIG. 10, in the fixing member 262, the thickness of the lower adhesive layer 212 does not change in the axial direction, whereas the thickness of the elastic layer 210B changes from the broken line S side (axial end portion side) to the broken line C side. It is thinner over the (axial center side). That is, the ratio of the thickness of the lower adhesive layer 212 to the thickness of the elastic layer 210B (the thickness of the lower adhesive layer 212 / the thickness of the elastic layer 210B) increases from the broken line S side to the broken line C side. Therefore, the storage elastic modulus of the elastic layer 210B is higher at the axially central portion where the thickness ratio (thickness of the lower adhesive layer 212 / thickness of the elastic layer 210B) is relatively higher than at both axial end portions. .
The hardness of the outer peripheral surface of the fixing member 262 tends to increase as the storage elastic modulus of the elastic layer 210B increases. For this reason, the hardness of the outer peripheral surface of the fixing member 262 at the central portion in the axial direction where the storage elastic modulus of the elastic layer 210B is high is higher than that at both axial end portions.
As a result, in the glossiness of the fixed image, the region corresponding to the axial central portion of the fixing member 262 having a relatively high outer peripheral surface hardness is lower than the region corresponding to both axial end portions, and the fixed image includes It is estimated that a difference in glossiness occurs.

On the other hand, in the fixing member 62A and the fixing member 62B shown in FIGS. 1 to 5, in addition to the elastic layer 110B, the lower adhesive layer 112 also has a flare shape. That is, as compared with the fixing member 262 of FIG. 10, the ratio of the thickness of the lower adhesive layer 112 to the thickness of the elastic layer 110B (the thickness of the lower adhesive layer 112 / the thickness of the elastic layer 110B) is greater than the axial end 62S. The rate of increase toward the axial center 62C is small. Therefore, the storage elastic modulus of the elastic layer 110 </ b> B in the axial central portion 62 </ b> C is lower than the storage elastic modulus in the axial central portion of the elastic layer 210 </ b> B in the fixing member 262. As a result, in the fixing member 62A and the fixing member 62B shown in FIGS. 1 to 5, the difference between the region corresponding to the axial center portion 62C and the region corresponding to the axial end portion 62S in the glossiness of the obtained fixed image. Is suppressed.
As described above, it is presumed that the difference in glossiness in the fixed image is suppressed in the fixing member of this embodiment.

In the fixing member 62A and the fixing member 62B, the thickness of the lower adhesive layer 112 at the axial center portion 62C is Tp ₁ c, the thickness of the lower adhesive layer 112 at the axial end portion 62S is Tp ₁ s, and the axial center. When the thickness of the elastic layer 110B in the portion 62C is Tec and the thickness of the elastic layer 110B in the axial end portion 62S is Tes, the thickness of the axial central portion 62C and the thickness of the axial end portion 62S in the lower adhesive layer 112 the ratio _{"Tp 1} c / _Tp 1 s" of any particular limitation to the ratio "Tec / Tes" with thicknesses of the axial end portion 62S of the axially central portion 62C, the magnitude of the elastic layer 110B Although _not, as compared with _{(Tp 1 c / Tp 1 s} ) <(Tec / Tes) satisfies the relationship (i.e., the elastic layer 110B toward the lower adhesive layer 112, the axial center And thinner the thickness of 62C, it is a great flared slope) is preferable from the viewpoint of suppression of gloss differences in the fixed image.

The reason is not clear, but is estimated as follows.
As described above, the hardness of the outer peripheral surface of the fixing member tends to increase as the storage elastic modulus of the elastic layer 110B increases. However, the hardness of the outer peripheral surface of the fixing member varies depending not only on the storage elastic modulus of the elastic layer 110B but also on the thickness of the elastic layer 110B. Specifically, the thinner the elastic layer 110B is, the more easily affected by the substrate 110A having a higher hardness than the elastic layer 110B, and the higher the hardness of the outer peripheral surface of the fixing member. That is, when the storage elastic modulus of the elastic layer 110B does not change in the axial direction, the thin axial center portion 62C of the elastic layer 110B has higher hardness on the outer peripheral surface of the fixing member than the axial end portion 62S. It is considered to be.
On the other hand, when the thicknesses of the elastic layer 110B and the lower adhesive layer 112 satisfy the relationship of (Tp ₁ c / Tp ₁ s) <(Tec / Tes), the storage / storage elastic modulus of the elastic layer 110B in the axial center portion 62C. However, it is rather smaller than the axial end 62S. Therefore, the influence of the thickness on the hardness of the outer peripheral surface of the fixing member and the influence of the storage elastic modulus are offset, the difference in hardness between the axial center portion 62C and the axial end portion 62S is suppressed, and the difference in glossiness in the fixed image. It is speculated that this is also suppressed.

  When the upper adhesive layer 114 which is a specific adhesive layer is provided as in the fixing member 62B shown in FIGS. 4 to 5, the upper adhesive layer 114 has a flare shape in addition to the elastic layer 110B and the lower adhesive layer 112. Is preferred. Since the upper adhesive layer 114 has a flare shape, a difference in glossiness in the fixed image is suppressed as compared with the case where a specific adhesive layer whose thickness does not change in the axial direction is provided instead of the upper adhesive layer 114. The reason is the same as the reason that the difference in glossiness is suppressed by making the lower adhesive layer 112 flared.

In the fixing member 62B, the thickness of the upper adhesive layer 114 at the axial center portion 62C is Tp ₂ c, the thickness of the upper adhesive layer 114 at the axial end portion 62S is Tp ₂ s, and the elastic layer 110B at the axial center portion 62C. The thickness of the elastic layer 110B at the axial end portion 62S is Tes, and the ratio between the thickness of the axial center portion 62C and the axial end portion 62S of the upper adhesive layer 114 is “Tp ₂ c / The magnitude relationship between “Tp ₂ s” and the ratio “Tec / Tes” between the thickness of the axial center portion 62C and the thickness of the axial end portion 62S in the elastic layer 110B is not particularly limited, but (Tp satisfy the relation of _{2 c / Tp 2 s) <} (Tec / Tes) ( i.e., toward the upper adhesive layer 114 as compared with the elastic layer 110B, the thickness of the axial central portion 62C Thinned, it is a great flared slope) is preferable from the viewpoint of suppression of gloss differences in the fixed image. The reason is the same as the reason why it is preferable to satisfy the relationship of (Tp ₁ c / Tp ₁ s) <(Tec / Tes) from the viewpoint of suppressing the difference in glossiness in the fixed image.

Here, the thickness of each layer constituting the fixing member is measured by using an eddy current film thickness meter CTR-1500E manufactured by Sanko Denshi. The thickness of each layer at a specific position in the axial direction of the fixing member (for example, the central portion 62C in the axial direction) is an average value obtained by measuring four locations in the circumferential direction at the specific position of the fixing member.
Further, whether or not the thickness of each layer increases from the axial center portion 62C toward the axial end portion 62S is determined by measuring the thickness from the one axial end portion 62S to the other axial end portion 62S. Confirm by performing 7 points in the direction at intervals close to equal intervals.

  The storage elastic modulus of the elastic layer 110B is performed as follows. Specifically, first, at the position of the measurement target in the axial direction of the fixing member (for example, the axial center portion 62C), the surface is cut into a ring shape on a plane perpendicular to the axial direction (that is, a plane along the circumferential direction). Then, a layer other than the elastic layer (for example, a base material) is peeled off. After the obtained elastic layer was shaped into a sheet having a width of 4 mm, a dynamic viscoelasticity test apparatus (manufactured by A & D Co., Ltd., DDV-01FP) was used to comply with JIS K7244-4, 160 Measure storage modulus at ° C.

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

(Base material)
As a base material, the thing using a resin material and a metal material is mentioned, for example. The fixing member may be a belt-like member (that is, a fixing belt) or a roll-like member (that is, a fixing roll), but has mechanical strength, flexibility, etc. when used as a belt-like member, for example. A material is preferable, and also from this viewpoint, a resin material and a metal material are preferable.

Examples of the resin material that can form the substrate include polyester, polyethylene terephthalate, polyether sulfone, polyether ketone, polysulfone, polyimide, polyimide amide, polyamide, and the like.
As a resin material constituting the base material, a resin called engineering plastic is generally preferable.
Engineering plastics that constitute the substrate include, for example, fluororesin, polyimide (PI, thermosetting polyimide, thermoplastic polyimide), fluorinated polyimide, polyamideimide (PAI), polybenzimidazole (PBI), and polyetheretherketone. (PEEK), polysulfone (PSU), polyethersulfone (PES), polyphenylene sulfide (PPS), polyetherimide (PEI), wholly aromatic polyester (liquid crystal polymer), and the like. Among these, polyimide, fluorinated polyimide, polyamideimide, polyetherimide, and the like are preferable in terms of mechanical strength, heat resistance, wear resistance, chemical resistance, and the like.

  When a resin material is used, the volume resistivity may be controlled by adding and dispersing a conductive agent (carbon black or the like).

As a metal material which can comprise a base material, various metals, such as SUS, nickel, copper, aluminum, are mentioned, for example.
Note that a resin material and a metal material may be laminated to form a base material.

The thickness of the substrate is not particularly limited. For example, when used as a fixing belt, the thickness is preferably 20 μm or more and 200 μm or less, more preferably 30 μm, from the viewpoint of having mechanical strength and ensuring flexibility. It is 150 μm or less, more preferably 40 μm or more and 130 μm or less, and particularly preferably 40 μm or more and 100 μm or less.
In addition, it is preferable that the thickness of a base material does not change along an axial direction from a viewpoint of mechanical strength.

  Note that the outer peripheral surface of the substrate may be activated by roughening treatment, discharge treatment, or the like in order to improve adhesion durability with the lower adhesive layer.

(Elastic layer)
The elastic layer is a layer provided from the viewpoint of imparting elasticity to the pressure applied from the outer peripheral side to the fixing member. For example, when used as a fixing belt in an image forming apparatus, the elastic layer is formed on the unevenness of the toner image on the recording medium. It is a layer that follows and plays a role of bringing the surface of the fixing member into close contact with the toner image.

  The elastic layer should just contain the silicone rubber (namely, specific silicone rubber) which has a carbon-carbon double bond (for example, vinyl group etc.) at least. When the elastic layer contains the specific silicone rubber, the adhesiveness with the specific adhesive layer that contacts the elastic layer (that is, the lower adhesive layer and the upper adhesive layer provided as necessary) is increased. Specifically, as described above, the carbon-carbon double bond of the pre-curing elastic layer and the hydrogen atom of the SiH structure of the pre-curing adhesive layer (that is, a hydrogen atom directly bonded to the Si atom) react and share. By forming a bond, high adhesion is obtained.

Specific silicone rubbers include, for example, RTV silicone rubber, HTV silicone rubber, liquid silicone rubber, and the like. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber ( PMQ) and fluorosilicone rubber (FVMQ).
Among these, an addition reaction type liquid silicone rubber which is a specific silicone rubber obtained by curing by an addition reaction between a polyorganosiloxane having an alkenyl group and a polyorganohydrogensiloxane having a SiH structure is preferable.
Examples of commercially available products include liquid silicone rubber SE6744 manufactured by Toray Dow Corning Silicone.

The elastic layer may include a material other than the specific silicone rubber as an elastic material. However, in the elastic material, it is preferable that the specific silicone rubber is a main component (that is, containing 50% or more by mass ratio), and the content is more preferably 90% by mass or more, and 99% by mass or less. More preferably it is.
Examples of materials other than the specific silicone rubber included as the elastic material include heat-resistant rubbers such as fluorine rubber, in addition to silicone rubbers other than the specific silicone rubber. Examples of the fluororubber include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphazene rubber, and fluoropolyether.
Examples of commercially available fluororubber include Viton B-202 manufactured by DuPont Dow elastmers.

The elastic layer may contain an inorganic filler for the purpose of reinforcement, heat resistance, heat transfer, and the like in addition to the elastic material. Examples of the inorganic filler include known ones, and preferred examples include fumed silica, crystalline silica, iron oxide, alumina, and metallic silicon.
In addition to the above, inorganic filler materials include carbides (for example, carbon black, carbon fiber, carbon nanotube, etc.), titanium oxide, silicon carbide, talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium oxide, Well-known inorganic fillers, such as graphite, silicon nitride, boron nitride, cerium oxide, magnesium carbonate, are mentioned.
Among these, silicon nitride, silicon carbide, graphite, boron nitride, and carbide are preferable from the viewpoint of thermal conductivity.
The content of the inorganic filler in the elastic layer may be determined depending on the required thermal conductivity, mechanical strength, etc., and examples include 1% by mass to 20% by mass, and 3% by mass to 15% by mass. % Or less is preferable, and 5 mass% or more and 10 mass% or less are more preferable.

  In addition, the elastic layer includes, as additives, for example, softeners (paraffins and the like), processing aids (stearic acid and the like), anti-aging agents (amines and the like), vulcanizing agents (sulfur, metal oxides, peroxides) Products), functional fillers (alumina, etc.) and the like.

As described above, the elastic layer has a flare shape.
Examples of the thickness Tec of the elastic layer in the central portion in the axial direction include 100 μm or more and 400 μm or less, preferably 125 μm or more and 300 μm or less, and more preferably 150 μm or more and 250 μm or less. Examples of the thickness Tes of the elastic layer at both axial ends include 200 μm or more and 600 μm or less, preferably 225 μm or more and 500 μm or less, and more preferably 250 μm or more and 400 μm or less.
Especially when the thickness of the elastic layer is in the above range, the difference in glossiness of the fixed image is likely to occur if the thickness of the lower adhesive layer does not change in the axial direction, but in this embodiment, the lower adhesive layer also has a flare shape. Therefore, the difference in glossiness is suppressed.
The ratio (Tec / Tes) of the elastic layer thickness Tec in the axial central portion to the elastic layer thickness Tes in both axial end portions is, for example, 0.2 or more and less than 1, and is a viewpoint of suppressing wrinkling of the recording medium. Therefore, 0.3 or more and 0.8 or less are preferable, and 0.4 or more and 0.7 or less are more preferable.

Examples of the storage elastic modulus Gc of the elastic layer in the central portion in the axial direction include 0.3 MPa or more and 2 MPa or less, preferably 0.4 MPa or more and 1.7 MPa or less, and more preferably 0.5 MPa or more and 1.5 MPa or less. Examples of the storage elastic modulus Gs of the elastic layer at both ends in the axial direction include 1 MPa or more and 3 MPa or less, preferably 1.5 MPa or more and 2.7 MPa or less, and more preferably 2 MPa or more and 2.5 MPa or less.
The ratio (Gc / Gs) of the storage elastic modulus Gc of the elastic layer in the central portion in the axial direction to the storage elastic modulus Gs of the elastic layer in both axial end portions is, for example, 0.1 or more and 1 or less. From the viewpoint of suppressing the difference in glossiness, it is preferably 0.3 or more and 0.8 or less, and more preferably 0.4 or more and 0.7 or less.
It is preferable that the storage elastic modulus Gs of the elastic layer at both axial end portions is higher than the storage elastic modulus Gc of the elastic layer at the axial central portion. When the storage elastic modulus Gs is higher than the storage elastic modulus Gc, peeling and breakage of the elastic layer due to deformation strain at both ends of the fixing member are suppressed, and as a result, durability of the fixing member is improved.

(Lower adhesive layer and upper adhesive layer)
The lower adhesive layer is a layer provided for the purpose of improving the adhesion between the substrate and the elastic layer, and is a flare-shaped specific adhesive layer (that is, a layer of a cured product of a composition containing polysiloxane having a SiH structure) ).
Further, the upper adhesive layer is a layer provided for the purpose of improving the adhesiveness between the elastic layer and the surface layer as necessary when the fixing member has a surface layer. The upper adhesive layer may be a specific adhesive layer or another adhesive layer, but is preferably a specific adhesive layer. In addition, when the upper adhesive layer is a specific adhesive layer, it is preferably a flare-shaped specific adhesive layer like the lower adhesive layer.

The thickness Tp ₁ c of the lower adhesive layer in the central portion in the axial direction is, for example, from 0.1 μm to 3 μm, preferably from 0.2 μm to 2.5 μm, and more preferably from 0.3 μm to 2 μm. The thickness Tp ₁ s of the lower adhesive layer at both axial ends is, for example, from 0.5 μm to 10 μm, preferably from 0.7 μm to 5 μm, and more preferably from 1 μm to 3 μm.
The ratio (Tp ₁ c / Tp ₁ s) of the thickness Tp ₁ c of the lower adhesive layer in the central portion in the axial direction to the thickness Tp ₁ s of the lower adhesive layer in both axial ends is, for example, 0.1 or more and 1 From the viewpoint of suppressing the difference in glossiness of the fixed image, it is preferably 0.15 or more and 0.7 or less, and more preferably 0.2 or more and 0.5 or less.

The ratio (Tp ₁ c / Tp ₁ s) of the lower adhesive layer thickness Tp ₁ c of the axial lower central portion to the lower adhesive layer thickness Tp ₁ s of both axial end portions is determined by the elastic layer in the axial central portion. The thickness Tec is preferably smaller than the ratio (Tec / Tes) to the thickness Tes of the elastic layer at both ends in the axial direction.
That is, (Tp ₁ c / Tp ₁ s) / (Tec / Tes) is preferably less than 1, more preferably 0.9 or less, and even more preferably 0.8 or less.

If an upper adhesive layer, the thickness Tp ₂ c of the upper adhesive layer in the axial central portion, for example, include 1μm or 20μm or less, preferably 3μm or more 20μm or less, more preferably 5μm or 15μm or less. The thickness Tp ₂ s of the upper adhesive layer at both axial ends is, for example, from 5 μm to 50 μm, preferably from 10 μm to 45 μm, and more preferably from 20 μm to 40 μm.
The ratio (Tp ₂ c / Tp ₂ s) of the thickness Tp ₂ c of the upper adhesive layer at the center in the axial direction to the thickness Tp ₂ s of the upper adhesive layer at both ends in the axial direction is, for example, 0.1 or more and less than 1. From the viewpoint of suppressing the difference in glossiness of the fixed image, it is preferably from 0.15 to 0.7, and more preferably from 0.2 to 0.5.
Further, the total thickness of the lower adhesive layer and the upper adhesive layer in the central portion in the axial direction is preferably 0.1 μm or more and 30 μm or less, and the total thickness of the lower adhesive layer and the upper adhesive layer in both ends in the axial direction is 0 It is preferably 5 μm or more and 50 μm or less.

The ratio (Tp ₂ c / Tp ₂ s) of the upper adhesive layer thickness Tp ₂ c in the axial center to the upper adhesive layer thickness Tp ₂ s at both axial ends is the thickness Tec of the elastic layer in the axial central portion. It is desirable that the ratio is smaller than the ratio (Tec / Tes) to the thickness Tes of the elastic layer at both ends in the axial direction.
That is, (Tp ₂ c / T2s) / (Tec / Tes) is preferably less than 1, more preferably 0.9 or less, and even more preferably 0.8 or less.

Hereinafter, the composition before curing of the specific adhesive layer (that is, the adhesive layer before curing) will be described.
The composition contains at least a polysiloxane having a SiH structure, and may contain other components in addition to a tetraalkoxysilane and an alkenyl silane coupling agent as required.

-Polysiloxane having SiH structure-
The polysiloxane having a SiH structure is a siloxane compound having one or more SiH structures (that is, a structure in which silicon atoms and hydrogen atoms are directly bonded) and two or more continuous siloxane bonds.
The number of SiH structures that one molecule of polysiloxane having an SiH structure has is 1 or more, and 2 or more is preferable from the viewpoint of providing adhesion to the elastic layer and rubber elasticity to the adhesive layer, and 2 or more and 10 or less. Is more preferable, and 2 or more and 4 or less are more preferable.
The number of Si atoms contained in one molecule of polysiloxane having a SiH structure is 3 or more, and from the viewpoint of improving adhesion and imparting rubber elasticity, it is preferably 3 or more and 100 or less.
The number average molecular weight of the polysiloxane having a SiH structure is, for example, 200 or more and 10,000 or less, and is preferably 200 or more and 6000 or less from the viewpoint of improving adhesiveness and imparting rubber elasticity.
The number average molecular weight is measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed with a THF solvent using a Tosoh GPC / HLC-8120GPC as a measuring device and a Tosoh column / TSKgel SuperHM-M (15 cm). The number average molecular weight is calculated from the measurement result using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample.

The molecular structure of the polysiloxane having a SiH structure may be linear, branched, or cyclic.
As polysiloxane which has SiH structure, the compound represented by following General formula (1) is mentioned, for example.

In general formula (1), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ each independently represent a hydrogen atom or a monovalent organic group, and n is 1 or more. Indicates an integer.

In the general formula (1), examples of the monovalent organic group represented by R ^{11 to} R ¹⁷ include a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted silyloxy group. It is done.

In general formula (1), examples of the alkyl group represented by R ^{11 to} R ¹⁷ include linear or branched alkyl groups having 1 to 4 carbon atoms (preferably 1 to 3 carbon atoms), and the like. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.
In the general formula (1), examples of the substituent of the alkyl group represented by R ^{11 to} R ¹⁷ include a substituted or unsubstituted aryl group and a substituted or unsubstituted silyloxy group described below.

In general formula (1), examples of the aryl group represented by R ^{11 to} R ¹⁷ include a phenyl group and a naphthyl group.
In the general formula (1), examples of the substituent of the aryl group represented by R ^{11 to} R ¹⁷ include the above-described substituted or unsubstituted alkyl group, the substituted or unsubstituted silyloxy group described below, and the like.

In the general formula (1), examples of the substituent of the silyloxy group represented by R ^{11 to} R ¹⁷ include the above-mentioned substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted silyloxy group, and the like. Is mentioned.

In general formula (1), R ^{11 to} R ¹⁷ are, among these, a hydrogen atom, an unsubstituted alkyl group having 1 to 2 carbon atoms, an unsubstituted group from the viewpoint of improving adhesion and imparting rubber elasticity. A phenyl group, an unsubstituted silyloxy group, and a silyloxy group substituted with an unsubstituted alkyl group having 1 to 2 carbon atoms are preferred, and a hydrogen atom and an alkyl group having 1 to 2 carbon atoms are more preferred.

When n in general formula (1) is 2 or more, two or more R ¹³ and R ¹⁴ in the compound represented by general formula (1) may be the same or different. Good, but preferably the same.
R ¹³ and R ¹⁴ in the general formula (1) may be the same or different from each other, but are preferably the same. R ¹¹ and R ¹² in the general formula (1) may be the same or different from each other, but are preferably the same. R ¹⁵ and R ¹⁶ in the general formula (1) may be the same or different from each other, but are preferably the same.

Among these, the compound represented by the general formula (1) is preferably a compound in which R ^{11 to} R ¹⁶ are hydrogen, a methyl group, or an ethyl group, and R ¹⁷ is a hydrogen atom, and R ^{11 to} R ¹⁶ are A compound in which both are methyl groups and R ¹⁷ is a hydrogen atom is more preferable.

  As content of polysiloxane which has SiH structure with respect to the whole composition, 1 mass% or more and 50 mass% or less are mentioned, for example, and 2 mass% or more and 30 mass% or less are preferable from a viewpoint of an adhesive improvement and applicability | paintability. .

-Tetraalkoxysilane-
Tetraalkoxysilane is a compound in which four alkoxy groups are bonded to Si atoms, and is represented by the following general formula (2).

In General Formula (2), R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent a substituted or unsubstituted alkyl group.

In general formula (2), examples of the alkyl group represented by R ^{21 to} R ²⁴ include linear or branched alkyl groups having 1 to 4 carbon atoms (preferably 1 to 3 carbon atoms). Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and an isobutyl group.
In the general formula (2), examples of the substituent of the alkyl group represented by R ^{21 to} R ²⁴ include a linear or branched alkoxy group, specifically, a methoxy group, an ethoxy group, a propoxy group, An isopropoxy group, a butoxy group, an isobutoxy group, etc. are mentioned.

In general formula (2), R ^{21 to} R ²⁴ are preferably an unsubstituted alkyl group, more preferably a methyl group, an ethyl group, or an n-propyl group, from the viewpoint of suppressing wrinkles of the recording medium. A methyl group and an ethyl group are more preferable, and a methyl group is particularly preferable.
R ^{21 to} R ²⁴ in the general formula (2) may be the same or different from each other, but are preferably the same.
Among these, the tetraalkoxysilane represented by the general formula (2) is preferably a compound in which R ^{21 to} R ²⁴ are a methyl group or an ethyl group, and a compound in which any of R ^{21 to} R ²⁴ is a methyl group. More preferred.

As content of the tetraalkoxysilane with respect to the whole composition, 1 mass% or more and 50 mass% or less are mentioned, for example, 2 mass% or more and 30 mass% or less are preferable. When the content of the tetraalkoxysilane is in the above range, the adhesive layer does not have too low hardness compared to the case where the content is less than the above range, and even if a load is applied due to the use of the fixing member, the elastic layer is peeled off, etc. Is suppressed.
The amount of tetraalkoxysilane contained in the composition with respect to 100 parts by mass of the polysiloxane having a SiH structure is, for example, 10 parts by mass to 500 parts by mass, and preferably 20 parts by mass to 300 parts by mass. .

-Silane coupling agent having an alkenyl group-
The alkenyl silane coupling agent is not particularly limited as long as it is a silane coupling agent having an alkenyl group.
Here, the silane coupling agent is a compound in which at least one of an alkoxy group and a halogen atom is directly bonded to a Si atom.
Moreover, as an alkenyl group, a C2-C4 alkenyl group is mentioned, for example, Specifically, a vinyl group, an allyl group, a butenyl group etc. are mentioned, for example. Moreover, as an alkenyl group, the alkenyl group which has a double bond at the terminal is preferable.

  Specific examples of the alkenyl silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltris (methoxyethoxy) silane, vinyltrichlorosilane, and allyltrimethoxysilane.

In particular, the alkenyl-based silane coupling agent is preferably a compound having an alkenyl group and three alkoxy groups directly bonded to the Si atom.
Moreover, as an alkenyl-type silane coupling agent, the compound represented by following General formula (3) is mentioned, for example.

In General Formula (3), R ³¹ , R ³² , and R ³³ each independently represent a substituted or unsubstituted alkyl group, and R ³⁴ represents a monovalent organic group having an alkenyl group.

In general formula (3), examples of the substituted or unsubstituted alkyl group represented by R ^{31 to} R ³³ are the same as the substituted or unsubstituted alkyl group represented by R ^{21 to} R ²⁴ in general formula (2). Can be mentioned.
R ^{31 to} R ³³ in the general formula (3) may be the same or different from each other, but are preferably the same.

In the general formula (3), examples of the monovalent organic group having an alkenyl group represented by R ³⁴ include an alkenyl group, an alkenyloxyalkyl group, an alkenylcycloalkyl group, and an alkenylaryl group.
In general formula (3), the monovalent organic group having an alkenyl group represented by R ³⁴ is preferably an alkenyl group, more preferably an alkenyl group having a double bond at the terminal, a vinyl group, an allyl group, A 3-butenyl group is more preferred, and a vinyl group is particularly preferred.

Among these, the alkenyl silane coupling agent represented by the general formula (3) is preferably a compound in which R ^{31 to} R ³³ are a methyl group or an ethyl group, and R ³⁴ is a vinyl group or an allyl group. ^A compound in which any of ^{31 to} R ³³ is a methyl group and R ³⁴ is a vinyl group is more preferable.

As content of the alkenyl-type silane coupling agent with respect to the whole composition, 1 mass% or more and 50 mass% or less are mentioned, for example, and 2 mass% or more and 30 mass% or less are from a viewpoint of an adhesive improvement and provision of rubber elasticity. preferable.
In addition, examples of the amount of the alkenyl silane coupling agent contained in the composition with respect to 100 parts by mass of the polysiloxane having a SiH structure include 20 parts by mass or more and 500 parts by mass or less, and 30 parts by mass or more and 300 parts by mass or less. The following is preferred.

-Other ingredients-
The composition may contain other components as required.
Examples of other components include a solvent (for example, butyl acetate) and inorganic particles (for example, iron oxide, silica, and the like).
The composition may further contain other silane coupling agents as other components. Other silane coupling agents include, for example, epoxy group silane coupling agents, amino group silane coupling agents, methacryl group silane coupling agents, styryl group silane coupling agents, and amino group silane coupling agents. Agents and the like.

(Surface layer)
The surface layer is, for example, a layer that plays a role of suppressing the adhesion of the molten toner image at the time of fixing to the surface (outer peripheral surface) that contacts the recording medium. A surface layer is provided as needed.
The surface layer is required to have heat resistance and releasability, for example. From this viewpoint, it is preferable to use a heat-resistant release material as the material constituting the surface layer, and specific examples include fluororubber, fluororesin, silicone resin, and polyimide resin.
Among these, a fluororesin is preferable as the heat-resistant release material.
Specific examples of such a fluororesin include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and polyethylene. -Tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), vinyl fluoride (PVF) and the like.

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

  The thickness of the surface layer is, for example, 10 μm to 100 μm, and is preferably 10 μm or more and 40 μm or less, and more preferably 20 μm or more and 30 μm or less from the viewpoint of suppressing gloss unevenness of a fixed image.

(Fixing member manufacturing method)
Next, a method for manufacturing the fixing member will be described. Here, a fixing belt having a surface layer on the elastic layer and an upper adhesive layer between the elastic layer and the surface layer is taken as an example.

−Preparation of elastic layer forming coating solution−
A liquid addition-curing silicone rubber mixture will be described as an example of the coating liquid for forming the elastic layer. First, an uncrosslinked silicone rubber is obtained by mixing an organopolysiloxane having an unsaturated bond (carbon-carbon double bond) such as a vinyl group and an organopolysiloxane having a Si-H bond. In this uncrosslinked silicone rubber, crosslinking proceeds by an addition reaction of Si—H to an unsaturated bond such as a vinyl group by heating or the like. In addition, you may contain crosslinking catalysts, such as a platinum compound which accelerates | stimulates reaction, and may contain the reinforcing filler which has OH group on the surface.

-Preparation of coating solution for forming specific adhesive layer-
As an application liquid for forming the specific adhesive layer, a liquid mixture containing A liquid: a liquid containing alkoxysilane and B liquid: a liquid containing polysiloxane having a SiH structure will be described as an example. By applying this mixed solution on the base material and the elastic layer before curing, the specific adhesive layer is formed by hydrolysis reaction and condensation reaction.

-Formation of each layer-
A specific adhesive layer forming coating solution for adhering the base material and the elastic layer to the surface of the base material inserted into a metal core or the like has a density distribution determined by a flow coating method (spiral winding coating). It coats so that it may become, and it dries and heats as needed. In other words, it is applied so that the coating density of the coating solution for forming the specific adhesive layer gradually increases from the axial center to both ends in the axial direction, and is dried and heated as necessary. An adhesive layer is formed. The application density is changed by, for example, changing the discharge speed of the coating liquid for forming the specific adhesive layer, changing the moving speed of the discharge portion, or a combination thereof.
In addition, as drying temperature in the said drying, 10 degreeC or more and 35 degrees C or less are mentioned, for example, As drying time, 10 minutes or more and 360 minutes or less are mentioned, for example. Moreover, as heating temperature in the said heating, the range of 100 to 200 degreeC is mentioned, As heating time, 10 minutes or more and 360 minutes or less are mentioned, for example. You may perform the said heating in inert gas (for example, nitrogen gas, argon gas, etc.) atmosphere.

  Next, a liquid elastic layer forming coating solution (addition-curable silicone rubber mixture) diluted with a solvent is applied onto the lower pre-curing adhesive layer with a density distribution determined by a flow coating method (spiral winding coating). It coats so that it may become, and it dries and heats as needed. That is, like the lower pre-curing adhesive layer, the elastic layer forming coating solution is applied so that the application density of the elastic layer forming solution gradually increases from the axial center to both axial ends. By heating, the pre-curing elastic layer is formed. The temperature and time for the drying and heating are the same as those for forming the lower pre-curing adhesive layer.

Next, a coating solution for forming a specific adhesive layer for adhering the elastic layer and the surface layer is applied onto the pre-curing elastic layer so as to have a density distribution determined by a flow coating method (spiral winding coating). Dry and heat as necessary. That is, as with the lower pre-curing adhesive layer, the specific adhesive layer forming coating liquid is applied so that the coating density gradually increases from the axial center to both axial ends, and dried as necessary. Then, the upper pre-curing adhesive layer is formed by heating. The temperature and time for the drying and heating are the same as those for forming the lower pre-curing adhesive layer.
In addition, as a coating solution for forming a specific adhesive layer for bonding the elastic layer and the surface layer, it is more preferable to use a solution diluted with a solvent permeable to silicone rubber.

Next, a releasable tube (for example, a PFA tube) serving as a surface layer is formed along the inner surface of a hollow metal tube (outer mold) having an inner diameter larger than the outer diameter of the cylindrical body coated with the elastic layer. Expand to stick by vacuum suction. And after inserting the core metal formed up to the upper pre-curing adhesive layer inside the mold with the releasable tube attached to the inner surface, release the vacuum suction of the outer mold and release the mold. The tube is coated on the pre-curing adhesive layer. Further, the core metal is taken out together with the laminate, and vulcanized to adhere the silicone rubber of the elastic layer and the release tube (PFA tube), and complete the crosslinking of the silicone rubber. Next, the belt is taken out from the mold, and both end portions are cut so as to have a predetermined length to obtain a fixing belt.
Examples of the vulcanization temperature in the vulcanization include 150 ° C. to 250 ° C., and examples of the vulcanization time include 30 minutes to 120 minutes.

[Fixing device]
Next, the fixing device according to this embodiment will be described.
The fixing device according to the present embodiment pressurizes the first rotator and the outer peripheral surface of the first rotator, and a recording medium having an unfixed toner image formed on the surface together with the first rotator. A fixing member according to the present embodiment described above. At least one of the first rotating body and the second rotating body is the fixing member according to the above-described embodiment.
The fixing member described above may be used as the first rotating body, may be used as the second rotating body, or may be used as both the first rotating body and the second rotating body. From the viewpoint of suppressing a difference in glossiness in a fixed image, it is preferable to use the above-described fixing member as a rotating body that directly contacts at least an unfixed toner image formed on a recording medium.

Hereinafter, as an example of the fixing device according to the present exemplary embodiment, a fixing belt that is a rotating body that is in direct contact with an unfixed toner image, and a pressure roll that applies pressure to the unfixed toner image via a recording medium are provided. The fixing device provided will be described. In the fixing device according to an embodiment shown below, the fixing member described above is applied as the fixing belt, but the fixing device is not limited thereto.
Further, the fixing device according to the present embodiment is not limited to one embodiment shown below, a pressure belt may be used instead of the pressure roll, a fixing roll may be used instead of the fixing belt, Instead of the fixing belt and the pressure roll, a fixing roll and a pressure belt may be used. The fixing member described above can be applied to any of a fixing belt, a fixing roll, a pressure belt, and a pressure roll.
Further, the fixing device according to the present embodiment is not limited to the following embodiment, and may be an electromagnetic induction heating type fixing device.

  FIG. 6 is a schematic cross-sectional view (that is, a schematic view in a cross section perpendicular to the axial direction of the fixing belt) of the fixing member as an example of the fixing device according to the present embodiment viewed from the axial direction side. 7 is a schematic cross-sectional view of the fixing device shown in FIG. 6 as viewed from the direction in which the recording medium is conveyed (that is, a schematic view in a cross section along the axial direction of the fixing belt).

  As shown in FIG. 6, the fixing device 60 according to the present embodiment includes, for example, a pressure roll 61 that is rotationally driven, and a fixing belt 62 (an example of a fixing member). Further, a pressing pad 64 (pressing member) that forms a contact portion through which the sheet K (an example of a recording medium) passes between the fixing belt 62 and the pressing roll 61 by pressing the pressing roll 61 via the fixing belt 62. 1) is provided inside the fixing belt 62. Further, a belt traveling guide 63 and a belt traveling assist guide 66 are provided inside the fixing belt 62, and the fixing belt 62 extends along the outer peripheral surfaces of the belt traveling guide 63, the belt traveling assist guide 66, and the pressing pad 64. Are configured to move around. The belt running guide 63 and the pressing pad 64 are attached to the holder 65 inside the fixing belt 62. A heating element 69 is provided between the belt running guide 63 and the fixing belt 62 as a heating source for the fixing belt 62.

  Further, as shown in FIG. 7, end guide members 71 are provided at both ends of the fixing belt 62 in the axial direction. The end guide member 71 includes a belt traveling end guide 72 and a meandering suppression guide 73 (an example of a meandering suppression member). The belt running end guide 72 is arranged in a state where it is inserted from both ends of the fixing belt 62, and is fixed to both ends of the holder 65. The outer peripheral surface of the belt traveling end guide 72 and the inner peripheral surface of the fixing belt 62 are in contact with each other, and the belt traveling end guide 72 supports both ends of the fixing belt 62 from the inner peripheral surface side. The meandering suppression guides 73 are arranged at a distance from each other so as to abut against the end surface of the fixing belt 62 during the meandering (belt walk) of the fixing belt 62.

  In the fixing device 60, the pressure roll 61 is rotated in the direction of arrow S by, for example, a drive motor (not shown), and the fixing belt 62 is driven by this rotation in the direction of arrow R opposite to the rotation direction of the pressure roll 61. Rotate to. That is, for example, while the pressure roll 61 rotates counterclockwise in FIG. 6, the fixing belt 62 rotates clockwise.

  Here, each member will be described in more detail.

-Pressure roll The pressure roll 61 is, for example, a solid metal core (columnar core) 61A, a heat-resistant elastic body layer 61B disposed around the core 61A, and a heat-resistant elastic body layer 61B. It is a cylindrical roll provided with the surface layer 61C arrange | positioned around. The pressure roll 61 is not limited in its shape, structure, size and the like, and a known pressure roll is used according to the purpose.

  Both end portions of the core 61A are rotatably supported by a bearing member (not shown), for example, and a predetermined pressure is applied to the fixing belt by biasing members such as coil springs disposed at both end portions of the core 61A. In contact.

  Examples of the material of the core 61A of the pressure roll 61 include iron, aluminum (for example, A-5052 material), a metal or alloy having high thermal conductivity such as SUS and copper, ceramics, fiber reinforced metal (FRM), and the like. It is done.

  The material of the heat-resistant elastic body layer 61B of the pressure roll 61 is, for example, rubber, elastomer, or foam having a hardness (JIS-A: hardness measured by a JIS-KA type testing machine) of 15 ° to 60 °. Examples of the resin include silicone rubber, fluorine rubber, and liquid silicone rubber filled with hollow glass beads. The thickness of the heat resistant elastic layer is not particularly limited, but is preferably in the range of 2 mm to 20 mm, and more preferably in the range of 3 mm to 10 mm.

  The material of the surface layer 61C of the pressure roll 61 may be a resin or the like. Examples of the resin for forming the surface layer 61C include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-, from the viewpoints of heat resistance and releasability. Fluororesin such as hexafluoropropylene copolymer (FEP), silicone resin, silicone rubber, fluororubber, fluorinated polyimide and the like.

The surface layer 61C preferably has conductivity, and is preferably a layer having a volume resistivity of 1 × 10 ⁴ Ωcm or less. Examples of the material for forming the conductive surface layer include resins containing conductive particles such as carbon black, graphite, and metal powder. The thickness of the surface layer is not particularly limited, but for example, a range of 10 μm to 200 μm is preferable, and a range of 20 μm to 100 μm is more preferable.
In this specification, the term “conductive” means that the volume resistivity at 20 ° C. is 10 ¹⁴ Ωcm or less.

Pressing pad The pressing pad 64 is supported by a holder 65 made of metal or the like, for example, inside the fixing belt 62. The pressing pad 64 is disposed so as to face the pressure roll 61 with the fixing belt 62 interposed therebetween, and presses the fixing belt 62 against the pressure roll 61 from the inner peripheral surface of the fixing belt 62 to thereby fix the fixing belt 62 and the pressure roll. A nip part through which the sheet passes is formed between

  It is sufficient that the fixing belt 62 and the pressure roll 61 are relatively pressurized. Therefore, the fixing belt 62 may be pressed toward the pressure roll 61 by the pressing pad 64. The pressure roll 61 may be pressed toward the fixing belt 62 side.

  The material of the pressing pad 64 is, for example, a resin such as silicone rubber, fluororubber, polyimide resin, polyamide resin, phenol resin, PES resin (polyethersulfone), PPS resin (polyphenylene sulfide), or a metal such as iron or aluminum. Etc. The resin may further contain conductive particles such as carbon black, graphite, and metal powder.

  In order to reduce the frictional resistance between the fixing belt 62 and each member in contact with the inner peripheral surface of the fixing belt 62 such as the pressure pad 64, a lubricant application member may be provided inside the fixing belt 62. A lubricant (for example, amino-modified silicone oil) is supplied to the inner peripheral surface of the fixing belt 62 by the lubricant application member.

A sliding member (not shown) may be provided between the fixing belt 62 and the pressing pad 64 in order to reduce the sliding resistance between the inner peripheral surface of the fixing belt 62 and the pressing pad 64. The sliding member may be composed of a single layer or may be composed of a plurality of layers. Examples of the material of the sliding member include sintered PTFE resin sheets, glass fiber sheets impregnated with fluororesin, and laminated sheets in which a fluororesin film sheet is heat-sealed and sandwiched between glass fibers.
Moreover, it is preferable that a lubricant permeation preventive layer that suppresses exhaustion of the lubricant is disposed on the sliding member. Examples of the material for the lubricant permeation prevention layer include heat resistant resin films and metal films that have heat resistance and do not allow lubricant to permeate.
In the case where the sliding member is not installed, the pressing pad 64 is made of, for example, a resin or metal containing particles capable of imparting conductivity so that the surface contacting the inner peripheral surface of the fixing belt 62 has conductivity. It is preferable that it is comprised.

Belt Running Guide and Heating Element The belt running guide 63 and the belt running auxiliary guide 66 are provided in an arc shape along the shape of the fixing belt 62 inside the fixing belt 62, and support the fixing belt 62 so that it can move around. .
The material of the belt traveling guide 63 and the belt traveling auxiliary guide 66 is, for example, heat-resistant resin such as polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), liquid crystal polymer (LCP), and further durability. And a filler for reducing the friction coefficient added to the heat-resistant resin.

Further, a heating element 69 is provided between the belt running guide 63 and the fixing belt 62 as a heating source for applying heat to the fixing belt 62.
The heating element 69 has, for example, an arc shape so as to follow the shape of the fixing belt 62. As the heating element, for example, a resistance heating element that generates Joule heat by supplying electric power is sandwiched between a pair of support plates, and heat generated from the resistance heating element is applied to the fixing belt 62 via the support plate. The mode transmitted is mentioned. The material of the support plate is preferably a metal such as aluminum or stainless steel from the viewpoint of heat transfer. The heating source of the fixing device 60 is not limited to a heating element, and for example, a known heating source such as a halogen lamp may be used.

End guide member The end guide member 71 is provided at both ends of the fixing belt 62 in the axial direction, is fixed to both ends of the holder 65, and contacts and supports both ends of the inner peripheral surface of the fixing belt 62. A belt running end guide 72 and a meandering suppression guide 73 (an example of a meandering suppression member) disposed at a position where it abuts against the end surface of the fixing belt 62 when the fixing belt 62 meanders (belt walk). Also, a holding portion 74 is provided on the opposite side of the belt running end guide 72 with respect to the meandering suppression guide 73, and the end guide member 71 is fixed by holding the holding portion 74 on the fixing device 60. Yes.
The material of the end guide member 71 (the belt travel end guide 72, the meandering suppression guide 73, and the holding portion 74) is, for example, polyphenylene sulfide (PPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or liquid crystal polymer. Examples thereof include a heat-resistant resin such as (LCP) and a material obtained by further adding a filler for lowering durability and a friction coefficient to the heat-resistant resin.

  Next, the operation of the fixing device 60 will be described.

  In the fixing device 60, the pressure roll 61 is rotated in the direction of arrow S by, for example, a driving motor (not shown), and the fixing belt 62 is rotated in the direction of arrow R opposite to the rotation direction of the pressure roll 61 following this rotation. To do. That is, for example, while the pressure roll 61 rotates counterclockwise in FIG. 6, the fixing belt 62 rotates clockwise. The rotation speed is not particularly limited, and is set to, for example, a surface speed of 250 mm / second.

  A sheet K (an example of a recording medium) on which the unfixed toner image G is formed is guided by a fixing inlet guide 56A and conveyed to a nip portion formed by a fixing belt 62 and a pressure roll 61. The When the paper K passes through the nip portion, the toner image G on the paper K is applied with pressure and heat acting on the nip portion, and is further guided and discharged by the fixing outlet guide 56B, so that the toner image G on the surface of the paper K is discharged. Image G is fixed.

Modifications In the fixing device 60 shown in FIGS. 6 and 7, the fixing belt 62 is in contact with the toner image G on the paper (recording medium) K, that is, the heating side where the fixing member is in contact with the toner image on the recording medium. The configuration in which the pressure belt is used as the fixing belt 62 and the pressure roller 61 is in contact with the back side of the recording medium has been described. However, the fixing device according to the present embodiment is not limited to these. For example, the fixing member described above may be used as a pressure belt that does not contact the toner image on the recording medium.

[Image forming apparatus]
Next, the image forming apparatus according to the present embodiment will be described.
The image forming apparatus of this embodiment includes an image carrier, a charging unit that charges the surface of the image carrier, and an electrostatic latent image forming unit that forms an electrostatic latent image on the charged surface of the image carrier. Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image; and transfer means for transferring the toner image to the surface of the recording medium; Fixing means for fixing the toner image to the recording medium. The fixing device according to this embodiment is applied as the fixing unit.

The image forming apparatus according to the present embodiment will be described below with reference to the drawings.
FIG. 8 is a schematic configuration diagram showing the configuration of the image forming apparatus according to the present embodiment.
As shown in FIG. 8, the image forming apparatus 100 according to the present embodiment is, for example, an intermediate transfer type image forming apparatus generally called a tandem type, and a plurality of toner images of each color component are formed by an electrophotographic system. Image forming units 1Y, 1M, 1C, and 1K, and a primary transfer unit 10 that sequentially transfers (primary transfer) the color component toner images formed by the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 15. The secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner image transferred onto the intermediate transfer belt 15 onto the paper K that is a recording medium, and the fixing that fixes the secondary transferred image onto the paper K. Device 60. Further, the image forming apparatus 100 includes a control unit 40 that controls the operation of each device (each unit).
This fixing device 60 is the fixing device 60 according to this embodiment described above.

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

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

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

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

The intermediate transfer belt 15 as an intermediate transfer member is formed of a film-like pressure belt containing a resin such as polyimide or polyamide as a base layer and containing an appropriate amount of an antistatic agent such as carbon black. The volume resistivity is 10 ⁶ Ωcm or more and 10 ¹⁴ Ωcm or less, and the thickness is, for example, about 0.1 mm.

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

The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photoconductor 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 is composed of a core body and a sponge layer as an elastic layer fixed around the core body. The core is a cylindrical bar made of a metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a mixed rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

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

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

The back roll 25 is made of a mixed rubber tube of EPDM and NBR with carbon dispersed on the surface, and the inside is made of EPDM rubber. And it is formed so that the surface resistivity may be 10 ⁷ Ω / □ or more and 10 ¹⁰ Ω / □ or less, and the hardness is set to, for example, 70 ° (Asker C: manufactured by Kobunshi Keiki Co., Ltd., the same shall apply hereinafter). The The back roll 25 is disposed on the back side of the intermediate transfer belt 15 to constitute a counter electrode of the secondary transfer roll 22, and a metal power supply roll 26 to which a secondary transfer bias is stably applied is disposed in contact. ing.

On the other hand, the secondary transfer roll 22 is composed of a core body and a sponge layer as an elastic layer fixed around the core body. The core is a cylindrical bar made of a metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a mixed rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ^7.5 Ωcm or more and 10 ^8.5 Ωcm or less.

  The secondary transfer roll 22 is placed in pressure contact with the back roll 25 with the intermediate transfer belt 15 interposed therebetween. Further, the secondary transfer roll 22 is grounded and a secondary transfer bias is formed between the secondary transfer roll 22 and the back roll 25, and the secondary transfer roll 22 is grounded. The toner image is secondarily transferred onto the paper K conveyed to the transfer unit 20.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

<Example 1>
In this example, a fixing belt for a fixing device corresponding to A4 paper lateral feed was manufactured.

-Base material A cylindrical polyimide base material having a diameter of 30 mm, a thickness of 60 μm, and a length of 400 mm was prepared, and after the surface was roughened, it was inserted into an aluminum cored bar.

-Lower adhesive layer A agent and B agent of silicone primer (silane coupling agent having hydrogen organopolysiloxane structure having SiH group, trade name: DY35-051, Toray Dow Corning Co., Ltd.) on the base material An equal amount of the mixed solution was applied by a flow coating method (spiral winding application).
During this application, the moving speed of the discharge nozzle that discharges the liquid mixture is controlled so that the thickness of the axial center portion is 0.5 μm and the thickness gradually increases from the axial center portion toward the axial end portion. Application was performed so that the thickness at both ends in the direction was 2.4 μm.
After coating, the coating was dried at room temperature (25 ° C.) for 30 minutes, and further heated at 150 ° C. for 30 minutes to perform a baking treatment, thereby forming a lower pre-curing adhesive layer.

-Elastic layer Next, as an application liquid for forming an elastic layer, acetic acid is added to an equal amount of an addition reaction type liquid silicone rubber (trade name: DY35-1310; Toray Dow Corning Co., Ltd.) A agent and B agent. A coating liquid (liquid silicone rubber) whose viscosity was adjusted by adding butyl was prepared. Thereafter, the prepared coating liquid (liquid silicone rubber) was applied on the lower pre-curing adhesive layer by a flow coating method (spiral winding coating).
At the time of this application, similarly to the case where the lower pre-curing adhesive layer is formed, the moving speed of the discharge nozzle for discharging the coating liquid (liquid silicone rubber) is controlled so that the axial center thickness is 180 μm. The coating was performed so that the thickness gradually increased from the center in the direction toward the end in the axial direction, and the thickness at both ends in the axial direction became 360 μm.
After coating, the solvent is removed by drying at 40 ° C. for 15 minutes, primary vulcanization is performed by heating at 115 ° C. for 15 minutes, and further secondary vulcanization is performed by heating at 200 ° C. for 60 minutes, A pre-curing elastic layer was formed.

-Upper adhesive layer Next, an addition reaction type silicone rubber adhesive containing polyorganohydrogensiloxane having SiH structure (trade name: SE1714, Toray Dow Corning Co., Ltd.) is diluted with heptane and then cured by flow coating. Application was performed on the front elastic layer.
At the time of this application, as in the case of forming the lower pre-curing adhesive layer, the moving speed of the discharge nozzle is controlled so that the thickness of the central portion in the axial direction is 10 μm from the central portion in the axial direction toward the axial end portion. Thus, the coating was performed so that the thickness gradually increased and the thickness at both axial ends was 40 μm.
After application, the film was dried at 60 ° C. for 15 minutes to form an upper pre-curing adhesive layer.

・ Surface layer Next, the PFA tube (inner surface activated treatment) to be the surface layer has an inner diameter slightly smaller than the outer diameter of the core metal on which the base material, the lower adhesive layer, the elastic layer, and the upper adhesive layer are formed. The hollow metal tube (outer mold) having a large inner diameter was expanded so as to adhere by vacuum suction along the inner surface of the hollow metal tube (outer mold).
Next, after inserting the core metal formed up to the upper pre-curing adhesive layer inside the outer mold with the PFA tube attached to the inner surface, the vacuum suction of the outer mold is released and the PFA tube is released. Was coated on the elastic layer. Further, the core metal was taken out together with the laminate, and heated at 200 ° C. for 4 hours to perform secondary vulcanization, thereby bonding the silicone rubber of the elastic layer and the PFA tube, and completing the crosslinking of the silicone rubber.
Next, after removing the belt from the mold, both ends were cut to a length of 253 mm to obtain a fixing belt.

The lower adhesive layer in the obtained fixing belt had a flare shape with a thickness of 0.5 μm at the axial center and 2.4 μm at both axial ends.
Further, the elastic layer in the obtained fixing belt had a flare shape with an axial center portion of 180 μm and axial end portions of 360 μm.
Further, the upper adhesive layer in the obtained fixing belt had a flare shape with a thickness of 10 μm at the axial center and 40 μm at both axial ends.
The surface layer of the obtained fixing belt had a thickness of 30 μm over the entire axial direction.

The obtained fixing belt was divided into 13 pieces into a 20 mm wide ring and cut to cut out the elastic layer, and the storage elastic modulus was measured by the method described above. The results are shown in FIG. In FIG. 9, the horizontal axis indicates the position (mm) from the end of the fixing belt in the axial direction, and the vertical axis indicates the storage elastic modulus (MPa). As shown in FIG. 9, the storage elastic modulus at the axial central portion was 1.4 MPa, the storage elastic modulus gradually increased toward the end, and the storage elastic modulus at the axial both ends was 2.4 MPa. .
Since the measurement of the storage elastic modulus is a destructive test, a fixing belt for the evaluation test prepared separately under the same conditions was separately prepared.

<Examples 2-3>
For the lower adhesive layer, the elastic layer, and the upper adhesive layer, a fixing belt was obtained in the same manner as in Example 1 except that the thicknesses of the central portion in the axial direction and both end portions in the axial direction were as shown in Table 1. Table 2 shows the storage elastic modulus of the elastic layer at the axial center and both axial ends.

<Example 4>
An adhesive layer other than the specific adhesive layer was provided as the upper adhesive layer.
Specifically, instead of forming the upper pre-curing adhesive layer, an adhesive (trade name: DY39-067, manufactured by Toray Dow Corning Co., Ltd.) is applied so that the thickness does not change in the axial direction at 25 ° C. A fixing belt was obtained in the same manner as in Example 1 except that it was dried for 60 minutes. Table 2 shows the storage elastic modulus of the elastic layer at the axial center and both axial ends.

<Example 5>

  In the formation of the lower pre-curing adhesive layer, instead of an equal mixture of the silicone primer (trade name: DY35-051) A and B agents, the silicone primer (trade name: primer No. 32A / B, Shin-Etsu) A fixing belt was obtained in the same manner as in Example 1 except that an equivalent mixed solution of Agent A and Agent B was used. Table 2 shows the storage elastic modulus of the elastic layer at the axial center and both axial ends.

<Comparative Example 1>
For the lower adhesive layer, the elastic layer, and the upper adhesive layer, a fixing belt was obtained in the same manner as in Example 1 except that the thicknesses of the central portion in the axial direction and both end portions in the axial direction were as shown in Table 1. Table 2 shows the storage elastic modulus of the elastic layer at the axial center and both axial ends.

<Evaluation>
-Evaluation of wrinkles on recording media-
The obtained fixing belt is incorporated in the fixing device shown in FIGS. 6 and 7, A4 paper is fed from a separately prepared paper feeding device, and a 10,000 sheet passing test is performed. The frequency of occurrence was confirmed. Specifically, the presence or absence of wrinkles on the 10,000 A4 sheets passed was visually checked, and the evaluation was made based on the number of A4 sheets on which wrinkles were confirmed. In the conventional fixing device, paper wrinkles are suppressed by making the pressure roll flare in the axial direction, but in this test, the stale shape (that is, the thickness does not change in the axial direction) as the pressure roll. ) Was used. The evaluation results are shown in Table 2.

-Evaluation of gloss difference-
The fixing device shown in FIGS. 6 and 7 incorporating the obtained fixing belt is incorporated in the image forming apparatus shown in FIG. 8, and is applied to a recording medium onto which an unfixed toner image having a high image density (image density 100%) is transferred. Then, fixing by the fixing device was performed to obtain a fixed image. The glossiness difference of the obtained fixed image (that is, the glossiness difference between the region corresponding to the central portion in the axial direction and the region corresponding to both end portions in the axial direction) was measured. The measurement was performed according to JIS Z 8741 using BYK-Gardner micro-TRI-gloss. The measurement angle was 60 °, the area corresponding to the central part in the axial direction and the area corresponding to both end parts in the axial direction were measured to determine the average glossiness, and the difference was defined as the glossiness difference. The results are shown in Table 2.

  From the results shown in Table 2, it can be seen that in this embodiment, the difference in glossiness of the fixed image is suppressed as compared with the comparative example.

1Y, 1M, 1C, 1K Image forming unit 10 Primary transfer unit 11 Photoconductor 12 Charger 13 Laser exposure unit 14 Developer 15 Intermediate transfer belt 16 Primary transfer roll 17 Photoconductor cleaner 20 Secondary transfer unit 22 Secondary transfer roll 25 Back roll 26 Power supply roll 31 Drive roll 32 Support roll 33 Tension applying roll 34 Cleaning back roll 35 Intermediate transfer belt cleaner 40 Control unit 42 Reference sensor 43 Image density sensor 50 Paper storage unit 51 Paper feed roll 52 Transport roll 53 Transport guide 55 Transport Belt 56 Fixing entrance guide 56A Fixing entrance guide 56B Fixing exit guide 60 Fixing device 61 Pressure roll 61A Core 61B Heat resistant elastic layer 61C Surface layer 62 Fixing belts 62A and 62B Fixing member 62C Axial center 62S Axial end 63 Belt running guide 6 Pressure pad 65 Holder 66 Belt running auxiliary guide 69 Heat generating element 71 End guide member 72 Belt running end guide 73 Meandering suppression guide 74 Holding unit 100 Image forming apparatus 110A Base material 110B Elastic layer 110C Surface layer 112 Lower adhesive layer 114 Upper side Adhesive layer G Unfixed toner image K Paper

Claims (8)

A cylindrical substrate;
An elastic layer that is disposed on the outer peripheral surface of the substrate and includes silicone rubber having a carbon-carbon double bond;
A lower adhesive layer, which is a cured product of a composition comprising polysiloxane having a SiH structure, disposed between and in contact with the elastic layer between the base material and the elastic layer;
Have
The elastic layer and the lower adhesive layer are fixing members that increase in thickness from an axial center portion to both end portions of the base material.   The fixing member according to claim 1, wherein a storage elastic modulus of the elastic layer in the central portion in the axial direction is lower than a storage elastic modulus of the elastic layer in both end portions in the axial direction. The thickness of the lower adhesive layer in the central portion in the axial direction is Tp ₁ c, the thickness of the lower adhesive layer in both end portions in the axial direction is Tp ₁ s, and the thickness of the elastic layer in the central portion in the axial direction. the Tec, when the thickness of the elastic layer in both end portions of the axial and _Tes, according to claim 1 or claim 2 satisfying the relation of _{(Tp 1 c / Tp 1 s} ) <(Tec / Tes) Fixing member.   The fixing member according to claim 1, further comprising a surface layer on an outer peripheral surface of the elastic layer.   A cured product of a composition comprising polysiloxane having a SiH structure, disposed between the elastic layer and the surface layer, in contact with the elastic layer, and having a thickness from the central portion in the axial direction toward both ends. The fixing member according to claim 4, further comprising an upper adhesive layer increasing. The thickness of the upper adhesive layer at the central portion in the axial direction is Tp ₂ c, the thickness of the upper adhesive layer at both axial end portions is Tp ₂ s, and the thickness of the elastic layer at the central portion in the axial direction is Tec. The fixing member according to claim 5, wherein the relationship of (Tp ₂ c / Tp ₂ s) <(Tec / Tes) is satisfied, where Tes is the thickness of the elastic layer at both ends in the axial direction. A first rotating body;
A second rotating body that pressurizes an outer peripheral surface of the first rotating body and sandwiches a recording medium having an unfixed toner image formed on the surface together with the first rotating body;
Have
The fixing device according to claim 1, wherein at least one of the first rotating body and the second rotating body is the fixing member according to claim 1. An image carrier,
Charging means for charging the surface of the image carrier;
An electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier;
Developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image;
Transfer means for transferring the toner image to the surface of the recording medium;
A fixing unit comprising the fixing device according to claim 7 and fixing the toner image on the recording medium;
An image forming apparatus comprising: