JP7275538B2 - Fixing member, manufacturing method thereof, and image forming apparatus having the same - Google Patents

Description

The present invention relates to a fixing member , a manufacturing method thereof, and an image forming apparatus having the same. More specifically, the present invention relates to a fixing member which is excellent in fixing separation property even when the paper output speed of the image forming apparatus is increased, and an image forming apparatus having the fixing member.

It is known that an electrophotographic image forming apparatus uses a fixing member such as a fixing belt or a fixing roller to fix unfixed toner onto a recording material.
However, in the case of fixing a print pattern on which toner has adhered to the entire surface, or in the case of a thin sheet of recording paper, there is a problem that the melted toner adheres to the fixing member, causing a paper jam. Furthermore, the problem of fixing separation has become more serious with the recent increase in the speed of image forming apparatuses (for example, the use of image forming apparatuses with a copying speed of 70 cpm or higher, so-called Seg. 5 or higher).

As a countermeasure for this, there is a method of suppressing sticking of the image to the belt by reducing the static friction force of the fixing member and improving the separability at the nip outlet. Patent Document 1 discloses a technique of applying a lubricant between a nip forming member and a fixing member to ensure low friction. In some cases it could not be guaranteed.

Further, Patent Documents 2 and 3 disclose techniques for maintaining stable transportability of a recording medium by reducing the coefficient of friction between a fixing member fixing member or a roller and the fixing member. If the amount of toner adhering to the image is large, the image may stick to the belt and the belt may rotate without being separated.
Patent Documents 4 and 5 disclose an electrophotographic member that uses a surface treatment layer composed of a surface modifier or a photocurable composition to achieve low friction. However, although both of them are effective in releasability of powder toner, they are insufficient in releasability of melted toner such as fixing member.

Furthermore, silicone can be cited as a material that enables low friction. As a fixing member having a silicone surface layer, Patent Document 6 discloses a fixing member provided with siloxane having a three-dimensional crosslinked structure. However, although it can solve the problem of emission and scattering of volatile organic compounds, there is a problem that it is difficult to develop low friction properties because the silicone structure has no flexibility.

JP 2018-13621 A JP 2010-78917 A JP 2015-55709 A JP 2014-197064 A JP 2017-83731 A JP 2015-212747 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems and circumstances, and an object thereof is to provide a fixing member that is excellent in fixing separation property even if the paper output speed of an image forming apparatus is increased. Another object of the present invention is to provide a manufacturing method thereof and an image forming apparatus having the same.

In order to solve the above problems, the inventors of the present invention, in the process of studying the causes of the above problems, found that the fixing member contains a condensate of organosilane having a specific structure and has a surface static friction coefficient of 0.09 or more and 0.09 or more. The present inventors have found that the above problem can be solved by setting the ratio to less than 20, leading to the present invention.
That is, the above problems related to the present invention are solved by the following means.

1. A fixing member used for fixing toner for electrostatic latent images, the fixing member having at least a base layer, an elastic layer and a surface layer, and having a static friction coefficient of the surface of the fixing member in an environment of 25°C. is in the range of 0.09 or more and less than 0.20, the three-dimensional arithmetic mean surface roughness Sa of the fixing member is in the range of 0.15 to 0.53 μm, and the surface layer has the following general formula: A fixing member containing a condensate of siloxane having the structure represented by (1).

(In the formula, R ₁ represents a hydrocarbon group. _{X 1} , X ₂ and X ₃ each independently represent an alkyl group or an alkoxyalkyl group. )

2. 3. The fixing member according to claim 1, wherein the three-dimensional arithmetic mean surface roughness Sa of the fixing member is in the range of 0.15 to 0.3 μm.

3. A fixing member used for fixing electrostatic latent image toner,
the fixing member has at least a base layer, an elastic layer and a surface layer;
a coefficient of static friction of the surface of the fixing member in an environment of 25° C. is in the range of 0.15 to 0.19;
The three-dimensional arithmetic mean surface roughness Sa of the fixing member is in the range of 0.33 to 0.53 μm, and
A fixing member, wherein the surface layer contains cyclohexyltrimethoxysilane, ethyltrimethoxysilane, or tris(2-methoxyethoxy)vinylsilane.

4. A fixing member manufacturing method for manufacturing the fixing member according to any one of items 1 to 3, comprising:
obtaining a mixture containing a siloxane having a structure represented by the general formula (1) and a solvent;
applying the mixture onto the elastic layer; and
curing the applied mixture by heating or drying to form the surface layer;
A method for manufacturing a fixing member, characterized by:

5 . An image forming apparatus comprising the fixing member according to any one of items 1 to 3 .

By the means of the present invention, even if the paper output speed of the image forming apparatus is increased, it is possible to provide a fixing member which is excellent in fixing separation property. Also, it is possible to provide the manufacturing method and an image forming apparatus having the same.

Although the expression mechanism or action mechanism of the effects of the present invention has not been clarified, it is speculated as follows. The fixing member using the condensate of organosilane according to the present invention has low frictional force generated at the interface with the image, and low abrasion. Furthermore, compared with the conventional perfluoroalkoxy resin (PFA), fluororubber, surface layer having both fluororesin and silicone, etc., it is more flexible and can follow the recording medium. Therefore, it is presumed that it is possible to output a high-quality image while maintaining high paper conveyability.

In addition, low friction means that the nano-order contact area due to deformation of the material species, called the true contact area, which is a factor in generating frictional force, is small. Because of this small net contact area, that is, the small contact area between the image and the fusing member, separation at the nip exit is facilitated.
Further, by lowering the coefficient of static friction, it is possible to ensure high paper transportability even under high nip pressure applied to the fixing member.

Furthermore, the fixing portion is subjected to a high temperature, causing a further increase in the coefficient of friction. Therefore, in order to achieve low friction, it is necessary to lower the coefficient of static friction at room temperature, and lower friction is required than in the transfer/development section. By using a material having a low coefficient of friction even at room temperature, as in the present invention, it is presumed that the paper can be strongly separated at the fixing portion.

Cross-sectional view showing an example of a fixing belt Cross-sectional view showing an example of a fixing roller A diagram showing an example of the internal configuration of the main body of the image forming apparatus.

The fixing member of the present invention is a fixing member used for fixing toner for electrostatic latent images, the fixing member has at least a base layer, an elastic layer and a surface layer, and the fixing member is capable of fixing under an environment of 25°C. The static friction coefficient of the surface of the member is within the range of 0.09 or more and less than 0.20, the three-dimensional arithmetic mean surface roughness Sa of the fixing member is within the range of 0.15 to 0.53 μm, and The surface layer is characterized by containing an organosilane condensate having a structure represented by the general formula (1).
Further, the fixing member of the present invention is a fixing member used for fixing the toner for electrostatic latent images, the fixing member has at least a base layer, an elastic layer and a surface layer, and is operable under an environment of 25°C. a coefficient of static friction of the surface of the fixing member is in the range of 0.15 to 0.19, and a three-dimensional arithmetic mean surface roughness Sa of the fixing member is in the range of 0.33 to 0.53 μm; and the surface layer contains cyclohexyltrimethoxysilane, ethyltrimethoxysilane, or tris(2-methoxyethoxy)vinylsilane.
These features are technical features common to or corresponding to the following embodiments.

As an embodiment of the present invention, from the viewpoint of exhibiting the effects of the present invention, it is preferable that the three-dimensional arithmetic mean surface roughness Sa of the fixing member is within the range of 0.15 to 0.3 μm.

The method for producing a fixing member of the present invention includes the steps of obtaining a mixture containing a siloxane having a structure represented by the general formula (1) and a solvent, applying the mixture onto the elastic layer, and applying a step of curing the mixture by heating or drying to form the surface layer.
Furthermore, the fixing member of the present invention can be suitably equipped in an image forming apparatus.
DETAILED DESCRIPTION OF THE INVENTION The present invention, its constituent elements, and embodiments and modes for carrying out the present invention will be described in detail below. In the present application, "-" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.
Further, in the present invention, the surface layer refers to the outermost layer of the fixing member.

<<Overview of Fixing Member of the Present Invention>>
The fixing member of the present invention is a fixing member used for fixing toner for electrostatic latent images, the fixing member has at least a base layer, an elastic layer and a surface layer, and the fixing member is capable of fixing under an environment of 25°C. The static friction coefficient of the surface of the member is within the range of 0.09 or more and less than 0.20, the three-dimensional arithmetic mean surface roughness Sa of the fixing member is within the range of 0.15 to 0.53 μm, and The surface layer is characterized by containing an organosilane condensate having a structure represented by the general formula (1). This feature is a technical feature common to or corresponding to each embodiment described below.
The configuration of the fixing member of the present invention will be described with reference to FIG. The cross-sectional view of the fixing member shown in FIG. 1 is merely an example, and the present invention is not limited to this.

In FIG. 1, a fixing member 10 of the present invention has an elastic layer 2 and a surface layer 3 on a base layer 1 in this order. The fixing member will be described below as a fixing belt, but may be in the form of a fixing roller having an elastic layer 2 and a surface layer 3 in this order on a base layer 1 as shown in FIG.
The fixing belt is preferably shaped like an endless belt. Here, the term "endless belt-like shape" means, for example, conceptually (geometrically) a loop-like shape formed by connecting both ends of one long sheet-like material. means. The actual shape of the fixing belt is preferably a seamless belt shape or a cylindrical shape.

The fixing member of the present invention contains an organosilane condensate having a structure represented by the general formula (1). Therefore, the frictional force generated at the interface with the image is low, and the abrasion is low. In addition, compared to conventional PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), fluororubber, and surface layers that have both fluororesin and silicone, it is more flexible and can follow the recording medium. can. Therefore, it is possible to output a high-quality image while maintaining high paper conveyability.
The organosilane condensate having the structure represented by formula (1) is preferably contained in the surface layer. Further, by having the elastic layer and the base layer as described above, not only is the fixing separability improved, but also the durability and the expansion of paper types can be improved.

In the present invention, a trifunctional organosilane represented by general formula (1) is used. Compared to the case of using a trifunctional organosilane, the use of a bifunctional organosilane reduces the number of bonds during organosilane condensation and increases the degree of freedom of molecules, resulting in a higher coefficient of static friction. Moreover, when a tetrafunctional silane is used, the number of bonds increases during condensation, so the degree of freedom of molecules is limited. Therefore, although the coefficient of static friction is lowered, it is too low, and the belt idles and the paper cannot be transported. Thus, the fuser member of the present invention contains a trifunctional organosilane condensate. In particular, the surface layer preferably contains a trifunctional organosilane condensate.

[Static friction coefficient]
In the present invention, HEIDON (portable friction meter TYPE: 94i-II) manufactured by Shinto Kagaku Co., Ltd. was used to measure the coefficient of static friction. Attach the flannel (cloth) to the slider. A sample to be measured is placed on a glass plate (Tempax), and measured using the above measuring instrument at room temperature of 25°C. The static friction coefficient of the surface of the fixing member of the present invention is in the range of 0.09 or more and less than 0.20, preferably in the range of 0.10 to 0.15.

[Three-dimensional arithmetic mean surface roughness Sa]
By reducing the three-dimensional arithmetic mean surface roughness Sa of the fixing member, the contact area between the image and the fixing member can be reduced, so that they can be easily separated at the nip outlet. In the present invention, the three-dimensional arithmetic mean surface roughness Sa of the fixing member is preferably 0.3 μm or less. The lower limit is about 0.001 μm due to manufacturing problems and the like.
Further, by lowering the coefficient of static friction, it is possible to ensure high paper transportability even under high nip pressure applied to the fixing member.

In the present invention, the three-dimensional arithmetic mean surface roughness Sa is a value measured according to the evaluation method (non-contact type) of ISO 25178 "Surface properties".
Specifically, VK-X250 manufactured by Keyence is used, and the field of view is 288×500 μm. The measurement is performed three times, and the arithmetic mean value of the three times can be obtained as the three-dimensional arithmetic mean surface roughness Sa.
Further, the surface roughness can be controlled by changing the conditions for diluting and drying the coating liquid for the surface layer when forming the surface layer. For example, by diluting the coating liquid, the intermolecular space becomes sparse and a smooth surface is produced, thereby reducing the roughness. In addition, by shortening the drying time, the diluent solvent dries faster and craters are more likely to occur, resulting in roughening.

<<Structure of fixing member>>
As described above, the fixing member 10 of the present invention can have the elastic layer 2 and the surface layer 3 on the base layer 1 in this order. Each layer may consist of multiple layers. Further, other functional layers may be provided on the back surface of the base layer 1, between the base layer 1 and the elastic layer 2, between the elastic layer and the surface layer, and the like. Functional layers include, for example, an antistatic layer, a smooth layer, a base layer, an adhesive layer, and the like.

[Base layer]
As the base layer of the fixing belt, heat-resistant belts and sheets are used, and polyimide, polyamide/polyamide-imide, thin-film SUS, thin-film nickel electroforming, etc. can be used. is preferred. The thickness of the base layer is preferably in the range of 10-1000 μm, more preferably in the range of 50-500 μm, even more preferably in the range of 50-200 μm.

[Elastic layer]
The elastic layer is preferably a layer containing a rubber member made of silicone rubber. The elastic layer preferably consists of two layers, a solid rubber layer and a sponge rubber layer. For example, the solid rubber layer preferably has a thickness of 50 to 350 μm, more preferably 100 to 250 μm.
On the other hand, the sponge rubber layer is a sponge-like soft layer containing countless microballoons. The thickness of the sponge rubber layer is preferably in the range of 5-100 μm, more preferably in the range of 80-90 μm.
The thickness of the entire elastic layer is preferably in the range of 150-400 μm, more preferably in the range of 150-250 μm.

The elastic layer is formed by forming a "precursor of silicone rubber" on the base layer before curing the silicone rubber raw material, which is molded from a low-molecular-weight monomer or the like, and then heat-treating the silicone rubber forming the rubber member. It can be hardened by
The heat treatment method is not particularly limited, and generally, the heating chamber is heated from the outside to heat the silicone rubber precursor stored inside the chamber. A heating method may be a batch type or a continuous type. For example, in the case of a batch method, the precursor of the silicone rubber may be left standing in the chamber and taken out after being heated for a predetermined period of time. In the case of a continuous method, the heating may be performed for a predetermined time while moving the base layer on which the silicone rubber precursor is formed inside the heating chamber.

Except for the step of heating the silicone rubber precursor for forming the rubber member, there is no particular limitation, and the fixing member can be manufactured using a known method.
A specific example of a method for forming a silicone rubber precursor, which is to be the rubber member of the fixing member, will be described below.

First, a curing agent (eg, CAT- 1602, manufactured by Shin-Etsu Chemical Co., Ltd.) is added and thoroughly mixed with a stirrer to obtain a first mixture.
Next, to this first mixture, for example, expanded heat-expandable microcapsules (for example, Expancel 461, which is a microballoon manufactured by Akzo Nobel) are added, mixed with a stirrer, and the heat-expandable microcapsules are mixed. A second mixture containing capsules is obtained.

Next, for example, on a heat-resistant belt made of polyimide as a base layer, the first mixture (not containing thermally expandable microcapsules) is applied by a coater and heated to complete curing to form a solid rubber layer. do.
Thereafter, a second mixture (containing thermally expandable microcapsules) is applied to this solid rubber layer to obtain a silicone rubber precursor.
Next, the silicone rubber precursor is heated in a heating chamber or the like to become silicone rubber constituting the rubber member of the fixing member to form an elastic layer.

Alternatively, after uniformly heating the entire precursor of the silicone rubber to crosslink it, the precursor of the silicone rubber may be further heated for a certain period of time as aging. By aging in this way, the low-molecular-weight siloxane remaining in the silicone rubber can be more volatilized, and as a result, the amount of low-molecular-weight compounds remaining in the silicone rubber can be further reduced, and the product can be used as a product. It is preferable because the amount of the low-molecular-weight compound that volatilizes upon heating can be reduced.

[Surface layer]
The surface layer according to the present invention is characterized by containing an organosilane condensate having a structure represented by the following general formula (1). Within the range of 0.09 or more and less than 0.20, it is possible to provide a fixing member capable of exhibiting high fixing separation performance even when the paper output speed of an image forming apparatus is increased.

[Organosilane Having a Structure Represented by Formula (1)]
The fixing member of the present invention contains an organosilane condensate having a structure represented by the following general formula (1).

(In the formula, R ₁ represents a hydrocarbon group. _{X 1} , X ₂ and X ₃ each independently represent an alkyl group or an alkoxyalkyl group. )

In general formula (1), R ₁ represents a hydrocarbon group. X ₁ , X ₂ and X ₃ each independently represent an alkyl group or an alkoxyalkyl group.

Hydrocarbon groups represented by R ₁ include alkyl groups, alkenyl groups, alkynyl groups and aryl groups. Among these, linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms are preferred.

Alkyl groups represented by X ₁ , X ₂ and X ₃ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n -pentyl group, isopentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, cyclopropyl group, cyclopentyl group and cyclohexyl group.

Also, R ₁ , X ₁ , X ₂ and X ₃ may be further substituted with substituents. Such substituents include alkyl groups, alkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, heterocyclic groups, alkoxy groups, cycloalkoxy groups, aryloxy groups, alkylthio groups, cycloalkylthio groups, arylthio groups, and alkoxycarbonyl groups. , aryloxycarbonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, carbamoyl group, ureido group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group or heteroarylsulfonyl group, amino group, halogen atom, fluorocarbon group, cyano group, nitro group, hydroxy group, mercapto group, silyl group, phosphono group, carboxy group, sulfo group and the like.

Specific examples of these include, but are not limited to, the following trifunctional organosilanes.
For example, trifunctional alkoxysilanes include methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltrimethoxysilane, n-decyltrimethoxysilane, n-dodecyltrimethoxysilane, n-tetradecyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane, methyltriethoxysilane, ethyl triethoxysilane, n-propyltriethoxysilane, isopropyltriethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-decyltriethoxysilane, n -dodecyltriethoxysilane, n-tetradecyltriethoxysilane, n-hexadecyltriethoxysilane and n-octadecyltriethoxysilane.

Such trifunctional organosilanes are also commercially available. For example, SR2441, SR2361 (manufactured by Toray Industries, Inc.) and the like can be mentioned.

The thickness of the surface layer is preferably in the range of 5 to 50 μm, more preferably in the range of 10 to 40 μm, particularly preferably in the range of 15 to 30 μm.
When the thickness of the surface layer is 5 μm or more, the effects of the present invention and the hardness of the surface layer itself can be maintained, and when the thickness is 50 μm or less, the elasticity of the elastic layer is not impaired, which is preferable.

<<Manufacturing Method of Fixing Member>>
In the method of manufacturing the fixing member of the present invention, after forming the elastic layer on the base layer, the organosilane having the structure represented by the general formula (1) and, if necessary, additives are added to the solvent, and the Step (a) of mixing to obtain a mixture, Step (b) of coating the mixture on the elastic layer, and thermosetting the coated mixture by heating to form a surface layer having the condensate of the organosilane. It is preferable to have a step (c) of performing.

Each of the steps (a) to (c) will be described.
The step (a) is a step of adding an organosilane and, if necessary, an additive to a solvent and mixing them in a mixer to obtain a mixture.

When they are mixed, it is preferable to adjust the respective mixing amounts so that the final volume ratio of the condensate of organosilane and the additive is within the range of 100:0 to 80:20.
As a device used for mixing, various known mixing devices such as a Turbular mixer, a Henschel mixer, a Nauta mixer, and a V-type mixer can be used.

Step (b) is a step of applying the mixture onto an elastic layer made of silicone rubber.
Coating methods include spin coating, casting, die coating, blade coating, roll coating, spray coating, curtain coating, and the like. , a die coating method, a roll coating method, a spray coating method, and other methods highly suitable for roll-to-roll systems are preferred.

Step (c) is a step of thermosetting the applied mixture by heating to form a surface layer containing the condensate of the organosilane. The heating conditions are preferably a temperature of 80 to 250° C. and a time of 20 minutes to 24 hours.
As a device for heating, a heating chamber is preferably used.

<<Overview of Image Forming Method>>
The image forming method used in the present invention is an image forming method comprising at least steps of developing an electrostatic latent image with toner to form a toner image, transferring the toner image to a recording medium, and fixing the toner image. The fixing member (eg, fixing belt) of the present invention is used in the fixing process.

The above steps include, in addition to the step of fixing the toner image onto the recording medium (hereinafter also simply referred to as "fixing step"), for example, the step of charging, the step of forming an electrostatic latent image, and the step of developing. , a transfer step, a cleaning step, and the like, which are used in general electrophotographic image forming methods.

The recording medium is not particularly limited, and known media can be used. Specifically, for example, in addition to paper such as plain paper and coated paper, fabric or sheet-like resin, etc. There are various media on which the material can be fixed.

[Toner Image]
A toner image is an image formed by developing an electrostatic latent image with toner.

In the present invention, the toner image transferred onto the recording medium is preferably a black toner image or a color toner image formed with toner of two or more colors. The variation of the color toner image is not particularly limited. For example, it may contain toner of at least two colors selected from cyan, magenta, yellow, and black, or two colors of black and white. , or a toner image containing toner of a plurality of colors.
According to the present invention, even with such a black toner image or a color toner formed with toner of two or more colors, the above effects can be favorably exhibited.

[Electrostatic latent image developing toner]
The toner according to the present invention is a toner for developing an electrostatic latent image (hereinafter referred to as "toner"), and contains at least toner particles.

In the present invention, "toner" refers to aggregates of "toner particles".
(toner particles)
The toner particles contain a binder resin containing at least a thermoplastic resin in the toner base particles, and optionally a release agent.

Here, "toner base particles" are particles containing at least a binder resin and a colorant. The toner base particles can be used as the toner particles as they are, but it is usually preferable to add an external additive to the toner base particles and use them as the toner particles.

The method for producing the toner base particles is not particularly limited, and known methods such as a kneading pulverization method, suspension polymerization method, emulsion aggregation method, dissolution suspension method, polyester elongation method, and dispersion polymerization method can be used.

(coloring agent)
Known materials such as yellow, magenta, cyan, and black dyes can be used as colorants for the toner base particles. A coloring agent (white) using inorganic particles such as titanium dioxide can also be used.
Specific examples of colorants are as follows.

Colorants for obtaining a black toner include carbon black, magnetic substances, iron-titanium composite oxide black, and the like, and carbon black includes channel black, furnace black, acetylene black, thermal black, lamp black, and the like. mentioned. Moreover, ferrite, magnetite, etc. are mentioned as a magnetic substance.

As a coloring agent for obtaining a yellow toner, C.I. I. Dyes such as Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112 and 162; I. Pigment Yellow 14, Pigment Yellow 17, Pigment Yellow 74, Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 138, Pigment Yellow 155, Pigment Yellow 180 and Pigment Yellow 185.

As a colorant for obtaining a magenta toner, C.I. I. Dyes such as Solvent Red 1, 49, 52, 58, 63, 111 and 122; C.I. I. Pigment Red 5, 48:1, 53:1, 57:1, 122, 139, 144, 149, 166, 177, 178, 222.

As a colorant for obtaining a cyan toner, C.I. I. Dyes such as Solvent Blue 25, 36, 60, 70, 93 and 95; C.I. I. Pigment Blue 1, 7, 15, 60, 62, 66, 76, 15:3.

Specific examples of white colorants include inorganic pigments (e.g., heavy calcium carbonate, light calcium carbonate, titanium dioxide, aluminum hydroxide, titanium white, talc, calcium sulfate, barium sulfate, zinc oxide, oxide Magnesium, magnesium carbonate, amorphous silica, colloidal silica, white carbon, kaolin, calcined kaolin, delaminated kaolin, aluminosilicate, sericite, bentonite, smectite, etc.), organic pigments (e.g., polystyrene resin particles, urea formalin resin particles, etc.). Pigments having a hollow structure, such as hollow resin particles and hollow silica, are also included.

Colorants for obtaining toner of each color can be used singly or in combination of two or more for each color.
The content of the colorant in the toner is preferably 0.5 to 20% by mass, more preferably 2 to 10% by mass.

(Binder resin)
The toner can contain a binder resin. It is generally known that toner particles having a substantially uniform particle size and shape can be produced by using an emulsion aggregation method as a toner production method.

For the toner, resins that are generally used as binder resins constituting toners can be used as the binder resin within a range that does not hinder the effect of the present invention. Examples of such resins include thermoplastic resins, and specific examples include styrene resins, acrylic resins, styrene-acrylic resins, polyester resins, silicone resins, olefin resins, amide resins and epoxy resins. These binder resins can be used alone or in combination of two or more.

Among these, the binder resin is at least one selected from the group consisting of styrene resins, acrylic resins, styrene-acrylic resins, and polyester resins, from the viewpoint of having low viscosity when melted and high sharp-melting properties. and more preferably at least one selected from the group consisting of styrene-acrylic resins and polyester resins.

The glass transition temperature (Tg) of the binder resin is preferably in the range of 30 to 70°C, more preferably in the range of 35 to 60°C, from the viewpoint of fixability and heat-resistant storage stability. Tg can be measured by differential scanning calorimetry (DSC).

(Release agent)
The toner may contain a release agent. The release agent used is not particularly limited, and various known waxes can be used. Waxes include low-molecular-weight polypropylene, polyethylene or oxidized low-molecular-weight polypropylene, polyolefins such as polyethylene, paraffin, and synthetic ester waxes. Synthetic ester waxes are particularly preferred because they have a low melting point and low viscosity. is preferred, and it is particularly preferred to use behenyl behenate, glycerin tribehenate, pentaerythritol tetrabehenate, etc. as the synthetic ester wax.

The content of the release agent is preferably in the range of 1 to 30% by mass, more preferably in the range of 3 to 15% by mass.

(Charge control agent)
The toner may contain a charge control agent. The charge control agent to be used is not particularly limited as long as it is a substance capable of imparting positive or negative charge by triboelectrification and is colorless. An electrostatic charge control agent can be used.
The content of the charge control agent is preferably in the range of 0.01 to 30 mass %, more preferably in the range of 0.1 to 10 mass % in the toner.

(external additive)
In order to improve the fluidity, chargeability, cleanability, etc. of the toner, the toner may be formed by adding an external additive such as a fluidizing agent, which is a so-called post-treatment agent, or a cleaning aid, to the toner particles. good.

Examples of external additives include inorganic oxide particles such as silica particles, alumina particles and titanium oxide particles, inorganic stearate compound particles such as aluminum stearate particles and zinc stearate particles, strontium titanate particles and zinc titanate particles. Inorganic particles such as inorganic titanate compound particles such as These can be used alone or in combination of two or more.

These inorganic particles may be surface-modified with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like in order to improve heat-resistant storage stability and environmental stability.
The amount of these external additives to be added is preferably 0.05 to 5% by mass, more preferably 0.1 to 3% by mass in the toner.

(Toner particle size)
The particle size of the toner is preferably 4 to 10 μm, more preferably 4 to 7 μm, in volume-based median diameter (D50). When the volume-based median diameter (D50) is within the above range, the transfer efficiency is increased, the image quality of halftones is improved, and the image quality of fine lines and dots is improved.

In the present invention, the volume-based median diameter (D50) of the toner is measured by "Coulter Counter 3" (manufactured by Beckman Coulter, Inc.), data processing software "Software
It is measured and calculated using a measuring device connected to a computer system (manufactured by Beckman Coulter, Inc.) equipped with "V3.51".

Specifically, 0.02 g of the measurement sample (toner) was added to 20 mL of a surfactant solution (for example, a surfactant obtained by diluting a neutral detergent containing a surfactant component 10 times with pure water for the purpose of dispersing toner particles). solution), followed by ultrasonic dispersion for 1 minute to prepare a toner dispersion. Pipette until the concentration indicated by the measuring device is 8%.

Here, by using this concentration range, it is possible to obtain reproducible measured values. Then, in the measuring device, the number of particles to be measured is 25000, the aperture diameter is 50 μm, the range of 1 to 30 μm which is the measurement range is divided into 256, and the frequency value is calculated. A particle diameter of 50% is defined as a volume-based median diameter (D50).

[About each process]
The steps used in a general electrophotographic image forming method, such as a charging step, an electrostatic latent image forming step, a developing step, a fixing step, and a cleaning step, are described below.

(Electrifying process)
In this step, the electrophotographic photosensitive member is charged. The charging method is not particularly limited, and for example, a known method such as a charging roller method in which the electrophotographic photosensitive member is charged by a charging roller may be used.

(Step of forming electrostatic latent image)
In this step, an electrostatic latent image is formed on an electrophotographic photosensitive member (electrostatic latent image carrier).
The electrophotographic photoreceptor is not particularly limited, and examples thereof include a drum-shaped one made of an organic photoreceptor such as polysilane or phthalopolymethine.

The electrostatic latent image is formed, for example, by uniformly charging the surface of the electrophotographic photosensitive member by charging means and exposing the surface of the electrophotographic photosensitive member imagewise by exposing means. The electrostatic latent image is an image formed on the surface of the electrophotographic photosensitive member by such charging means.
Charging means and exposure means are not particularly limited, and those commonly used in electrophotography can be used.

(Process of developing)
The developing step is a step of developing the electrostatic latent image with toner (generally, a dry developer containing toner) to form a toner image.
The formation of the toner image is performed, for example, by using a dry developer containing toner, using a stirrer for frictionally stirring and charging the toner, and developing means having a rotatable magnet roller.

Specifically, in the developing means, for example, toner and carrier are mixed and agitated, and the toner is charged by friction at that time, held on the surface of a rotating magnet roller, and a magnetic brush is formed. Since the magnet roller is arranged in the vicinity of the electrophotographic photosensitive member, part of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrophotographic photosensitive member due to the electric attraction force. . As a result, the electrostatic latent image is developed with toner to form a toner image on the surface of the electrophotographic photosensitive member.

(Step of transferring)
In this step, the toner image is transferred onto the recording medium.
The toner image is transferred to the recording medium by charging the toner image to the recording medium.
As a transfer means, for example, a corona transfer device using corona discharge, a transfer belt, a transfer roller, or the like can be used.

In the transferring step, for example, an intermediate transfer member is used to primarily transfer a toner image onto the intermediate transfer member, and then the toner image is secondarily transferred onto a recording medium. It is also possible to transfer the formed toner image directly onto the recording medium.

(Fixation process)
In the fixing step according to the present invention, the recording material onto which an unfixed image (toner image) formed using toner is transferred is passed between a heated fixing belt or fixing roller and a pressure member. fixing the unfixed image on the recording material. When the fixing belt or fixing roller used is the fixing member of the present invention, even if the paper output speed of the image forming apparatus is increased (copying speed of 70 cpm or higher, so-called Seg.5 or higher image forming apparatus is used). , it is possible to obtain the effect of exhibiting high fixing separation performance and not causing image unevenness.

Specifically, the method of the fixing process includes, for example, a fixing belt or a fixing roller as a fixing rotating body, and a press provided in a state in which the fixing belt or the fixing roller is in pressure contact so as to form a fixing nip portion. A belt fixing system or a roller fixing system comprising a pressure roller as a pressure member may be used.

(Cleaning process)
In this step, developer that has not been used for image formation or that has not been transferred is removed from the developer carrier such as a photoreceptor or an intermediate transfer member.
The cleaning method is not particularly limited, but it is preferable to use a blade that scrapes the surface of the photoreceptor and whose tip is in contact with the object to be cleaned, such as the photoreceptor.

<<Image forming apparatus>>
An image forming apparatus of the present invention is characterized by comprising the fixing member of the present invention. Other than using the fixing member of the present invention for an image forming apparatus, a general image forming apparatus can be used.

The configuration of the image forming apparatus main body 100 will be described with reference to FIG. FIG. 3 is a diagram showing the internal configuration of the image forming apparatus main body 100. As shown in FIG.
As shown in FIG. 3, the image forming section 40 has image forming units 41Y, 41M, 41C, and 41K that form images with YMCK color toners under the control of an image control CPU (Central Processing Unit). Since they all have the same configuration except for the toner contained therein, the symbols representing the colors may be omitted hereinafter. The image forming section 40 further has an intermediate transfer unit 42 and a secondary transfer unit 43 .

The image forming unit 41 has an exposure section 411 , a development section 412 , a photosensitive drum 413 , a charging section 414 and a drum cleaning section 415 . The photoreceptor drum 413 is, for example, a negatively charged organic photoreceptor. The surface of the photosensitive drum 413 has photoconductivity. The charging unit 414 is, for example, a corona charger. The charging unit 414 may be a contact charging device that charges the photosensitive drum 413 by bringing a contact charging member such as a charging roller, a charging brush, or a charging blade into contact with the photosensitive drum 413 . The exposure unit 411 includes, for example, an LD (LASER Diode) 411a that outputs a laser beam as a light source, and a light deflection device (polygon motor) that irradiates a photosensitive drum 413 with a laser beam corresponding to an image to be formed. include.

The developing unit 412 is a two-component developing device. The developing unit 412 includes, for example, a developing container containing a two-component developer, a developing roller (magnetic roller) rotatably disposed at an opening of the developing container, and a developing container in which the two-component developer can communicate. a partition wall for partitioning the inside, a transport roller for transporting the two-component developer on the opening side of the developing container toward the developing roller, and a stirring roller for stirring the two-component developer in the developing container. . The developing container contains the toner as a two-component developer.

The intermediate transfer unit 42 has a primary transfer roller 422 that presses the intermediate transfer belt 421 against the photosensitive drum 413 , a plurality of support rollers 423 including a secondary transfer roller Up (backup roller) 423 A, and a belt cleaning section 426 . The intermediate transfer belt 421 is stretched around a plurality of support rollers 423 in a loop shape. As at least one drive roller among the plurality of support rollers 423 rotates, the intermediate transfer belt 421 travels in the direction of arrow a at a constant speed.

The secondary transfer unit 43 has an endless secondary transfer belt 432 and a plurality of support rollers 431 including a secondary transfer roller Lw (lower side) 431A. The secondary transfer belt 432 is stretched in a loop shape by the secondary transfer roller Lw431A and the support roller 431 .

The fixing section 60 heats and presses the sheet on which the toner image is formed by the image forming section 40 under the control of the image control CPU. The fixing unit 60 includes an endless fixing belt 61, which is a fixing member according to the present invention, a heating roller 62, a fixing roller 63 arranged to face a pressure roller 64, a pressure roller 64, and an air separator. a portion 65; The fixing belt 61 is stretched between the heating roller 62 and the fixing roller 63 . The heating roller 62 incorporates heating means such as a halogen heater (not shown) for heating the fixing belt 61 . The fixing roller 63 forms a nip portion N between the fixing belt 61 and the pressure roller 64 .

In the above configuration, when the pressure roller 64 is rotated counterclockwise by a driving means (not shown), the fixing belt 61, the heating roller 62, and the fixing roller 63 are rotated clockwise. The fixing belt 61 is heated by the heating roller 62 in contact with it, and the fixing roller 63 is also heated. Then, the sheet on which the toner image is formed is heated and pressurized by passing through the nip portion N, and the toner image transferred onto the sheet is fused and fixed.

Further, the air separating portion 65 blows air onto the paper discharged from the nip portion N to separate the paper from the fixing belt 61 . The air separating section has a suction fan (not shown) that sucks air from the outside and sends the air in the direction of the nip portion N, and a duct that is a path for the sent air. By separating the paper from the fixing belt 61 by the air separation unit 65, the paper can be separated without contacting the surface of the fixing belt 61 with members such as separation claws, so that the surface of the fixing belt 61 is not damaged. no.

The image forming apparatus main body 100 further includes a scanner section 30 , a reading processing section 13 , a paper feed section 50 and a paper transport section 70 . The scanner unit 30 has a paper feeding device 301 and a scanner 302 . Under the control of the image control CPU, the scanner unit 30 feeds the document d from the paper feeding device 301 and scans the document d with the CCD (Charge Coupled Device) sensor 32 of the scanner 302 to obtain input image data. The paper feed unit 50 has paper feed units 50a and 50b. The paper feeding unit 50 feeds the paper S to the image forming unit 40 under the control of the image control CPU. In the three paper feed tray units 51a, 51b, and 51c constituting the paper feed section 50a and the external paper feed section 50b, the paper S (standard paper, special paper) identified based on basis weight, size, etc. is stored. They are accommodated according to preset types.

The paper transport section 70 has a paper discharge section 72 and a transport path section 73 . The paper conveying portion 70 conveys the paper S to the image forming portion 40 by the conveying path portion 73 and discharges the paper S from the fixing portion 60 by the paper discharging portion 72 according to the image control CPU. The transport path portion 73 has a plurality of transport roller pairs such as a registration roller pair 73a. The sheet conveying section 70 has a reversing path section for reversing the sheet on which an image has been formed on one side and conveying the sheet to the image forming section 40 again.

Here, an example of an image forming method by the image forming apparatus main body 100 will be described. The scanner 302 optically scans and reads the document d that has been fed onto the contact glass by the feeding device 301 or placed on the platen glass. Reflected light from the document d is read by the CCD sensor 32 of the scanner 302 and becomes input image data. The input image data undergoes predetermined image processing in the reading processing unit 13 and is sent to the exposure unit 411 .

The photosensitive drum 413 rotates at a constant peripheral speed. The charging unit 414 uniformly charges the surface of the photosensitive drum 413 to a negative polarity. In the exposure unit 411, the polygon mirror of the polygon motor rotates at high speed, and the laser light corresponding to the input image data of each color component develops along the axial direction of the photoreceptor drum 413. The outer peripheral surface of the drum 413 is irradiated. An electrostatic latent image is thus formed on the surface of the photosensitive drum 413 .

In the developing section 412, the toner particles are charged by stirring and transporting the two-component developer in the developer container, the two-component developer is transported to the developing roller, and forms a magnetic brush on the surface of the developing roller. The charged toner particles are electrostatically adhered from the magnetic brush to portions of the electrostatic latent image on photoreceptor drum 413 . Thus, the electrostatic latent image on the surface of the photoreceptor drum 413 is visualized, and a toner image corresponding to the electrostatic latent image is formed on the surface of the photoreceptor drum 413 .

The toner image on the surface of the photosensitive drum 413 is transferred to the intermediate transfer belt 421 by the intermediate transfer unit 42 . Transfer residual toner remaining on the surface of the photoreceptor drum 413 after transfer is removed by a drum cleaning section 415 having a drum cleaning blade that slides on the surface of the photoreceptor drum 413 .

By pressing the intermediate transfer belt 421 against the photoreceptor drum 413 by the primary transfer roller 422 , the photoreceptor drum 413 and the intermediate transfer belt 421 form a primary transfer nip for each photoreceptor drum. At the primary transfer nip, toner images of respective colors are transferred onto the intermediate transfer belt 421 so as to overlap one another.

On the other hand, the secondary transfer roller Lw431A is pressed against the secondary transfer roller Up423A with the intermediate transfer belt 421 and the secondary transfer belt 432 interposed therebetween. Thereby, the intermediate transfer belt 421 and the secondary transfer belt 432 form a secondary transfer nip. The paper S passes through the secondary transfer nip. The sheet S is conveyed to the secondary transfer nip by the sheet conveying section 70 . Correction of the skew of the sheet S and adjustment of the transport timing are performed by a registration roller section in which a pair of registration rollers 73a are arranged.

When the sheet S is conveyed to the secondary transfer nip, a transfer bias is applied to the secondary transfer roller Lw431A. The toner image carried on the intermediate transfer belt 421 is transferred to the sheet S by applying the transfer bias. The sheet S onto which the toner image has been transferred is conveyed toward the fixing section 60 by the secondary transfer belt 432 .

The fixing section 60 forms a nip portion N with the fixing belt 61 and the pressure roller 64 , and heats and presses the conveyed sheet S at the nip portion N.
In the belt heating type fixing device, the temperature of the heating member is preferably relatively low, specifically, it can be 150° C. or less. Furthermore, the temperature of the heater is more preferably 140° C. or lower, particularly preferably 135° C. or lower. Although the lower limit of the temperature of the heater is not particularly limited, it is substantially about 90°C.

The toner particles forming the toner image on the paper S are heated, and the crystalline resin inside them melts rapidly. adhere to. Thus, the toner image is quickly fixed on the sheet S with a relatively small amount of heat. The paper S on which the toner image is fixed is discharged to the image reading device 200 by the paper discharge section 72 provided with the paper discharge roller 72 a of the paper conveying section 70 . Thus, a high quality image is formed.

The transfer residual toner remaining on the surface of the intermediate transfer belt 421 after the secondary transfer is removed by a belt cleaning section 426 having a belt cleaning blade that slides on the surface of the intermediate transfer belt 421 .

In the above description, the fixing belt is used as the fixing member, but a fixing roller can be similarly manufactured and used.
The fixing roller is a rubber roller for fixing toner onto paper in an electrophotographic image forming apparatus, and is formed by using an elastic layer made of a silicone rubber composition as an outer layer of a core material and a surface layer according to the present invention. be. As the fixing roller, for example, a cylindrical roller having a silicone rubber (hereinafter also simply referred to as a rubber member) as an elastic layer can be used.

The rubber member of the fixing roller preferably has a rubber hardness within the range of 30 to 60°. Also, the rubber hardness can be adjusted, for example, by heating temperature and heating time in molding or vulcanization.

The on-axis rubber hardness is obtained by measuring the surface hardness of the fixing roller according to JIS-S-6050. Specifically, the ASKER-C type rubber hardness tester manufactured by Kobunshi Keiki Co., Ltd. is used for measurement under a load of 600 g. Further, in order to observe the rubber hardness on the shaft, the measurement is performed using a positioning member in which the vertical part in the circumferential direction of the roller is positioned directly below the pressing indenter. As the fixing roller, a roller having a core diameter of 22 mm, a rubber thickness of 4 mm, and an outer diameter of 30 mm was manufactured, and rubber hardness was measured. Further, in the measurement of rubber hardness, the hardness is measured in a state where the rubber is placed on the surface of the core material.

The fixing roller includes a core metal, a solid rubber layer provided as an elastic layer so as to cover the outer peripheral surface of the core metal, and a sponge rubber layer and a surface layer provided so as to cover the outer peripheral surface of the solid rubber layer. Although it may have a four-layer structure of, it is not limited to these.

In the fixing roller, the metal core is preferably made of a metal material such as aluminum, iron, and SUS. The thickness of the cored bar is about 0.1 to 5 mm, and more preferably about 0.1 to 1.5 mm in consideration of weight saving and warm-up time. The diameter of the cored bar is preferably about 10 to 50 mm.

The solid rubber layer and the sponge rubber layer are preferably made of silicone rubber as described above.
The silicone rubber has heat resistance to the fixing temperature and elasticity for ensuring the dimension of the area where the paper is pressed (the length of the nip portion).

The solid rubber layer is a solid hard layer. The thickness of the solid rubber layer 214 is preferably within the range of 5-10 mm, more preferably within the range of 7-8 mm.
On the other hand, the sponge rubber layer 216 is a sponge-like soft layer containing countless microballoons. The thickness of the sponge rubber layer 216 is preferably within the range of 5-100 μm, more preferably within the range of 80-90 μm.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these. In the examples, "parts" or "%" are used, but "mass parts" or "mass%" are indicated unless otherwise specified.

<<Fabrication of fixing member>>
A base layer made of polyimide was used as a fixing member, and a coating liquid for a surface layer was applied on an elastic layer made of silicone rubber, and cured to form a fixing belt in the following manner. The surface roughness was controlled by changing the dilution conditions and drying conditions of the surface layer coating liquid as described below. The thickness of the surface layer was in the range of 5-60 μm.

[Fabrication of Fixing Belt 1]
A polyimide substrate having a thickness of 70 μm was used as the base layer. Next, an elastic layer 1 having a thickness of 200 μm containing a solid rubber layer and silicone rubber was formed on the substrate by the method described above.

Next, cyclohexyltrimethoxysilane (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was dissolved in MEK (methyl ethyl ketone) in a volume ratio of 50% with respect to the silane, and then applied onto the elastic layer 1 as a surface layer coating liquid. . After drying at 80° C. for 1 hour, it was dried at room temperature (25° C.) for 1 week, and fixing belt 1 having surface layer 1 was produced. The three-dimensional arithmetic mean surface roughness Sa was 0.43 μm.

[Fabrication of Fixing Belt 2]
In the production of the fixing belt 1, only the surface layer was changed as follows to produce the fixing belt 2 having the surface layer 2 on the elastic layer 1 described above.
Ethyltrimethoxysilane (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was dissolved in MEK at a volume ratio of 60% with respect to the silane, coated on the elastic layer 1, dried at 80 ° C. for 1 hour, and dried at room temperature (25 ° C.) for one week to prepare a fixing belt 2 having a surface layer 2 . The three-dimensional arithmetic mean surface roughness Sa was 0.33 μm.

[Production of fixing belt 3]
After dissolving tris(2-methoxyethoxy)vinylsilane (Tokyo Chemical Industry Co., Ltd.) in MEK having a volume ratio of 60% with respect to the silane, the solution was applied onto the elastic layer 1 and dried at 80°C for 1 hour. It was dried at room temperature (25° C.) for one week to prepare a fixing belt 3 having a surface layer 3 . The three-dimensional arithmetic mean surface roughness Sa was 0.53 μm.

[Fabrication of Fixing Belt 4]
A mixed solution obtained by mixing 50 parts by mass of trifunctional organosilane SR2441 (manufactured by Dow Toray Co., Ltd.) and 50 parts by mass of trifunctional organosilane SR2361 (manufactured by Dow Toray Co., Ltd.) in a mixer was applied onto the elastic layer 1. It was applied and cured at room temperature (25° C.) for 12 hours to prepare a fixing belt 4 having a surface layer 4 . Surface roughness The three-dimensional arithmetic mean surface roughness Sa was 0.33 μm.

[Fabrication of Fixing Belt 5]
SR2441 (manufactured by Dow Toray Co., Ltd.), which is a trifunctional organosilane, was applied onto the elastic layer 1 and cured at room temperature (25° C.) for 12 hours to prepare a fixing belt 5 having a surface layer 5 . The three-dimensional arithmetic mean surface roughness Sa was 0.24 μm.

[Production of fixing belt 6]
SR2361 (manufactured by Dow Toray Co., Ltd.), which is a trifunctional organosilane, was applied onto the elastic layer 1 and cured at room temperature (25° C.) for 12 hours to prepare a fixing belt 6 having a surface layer 6 . The three-dimensional arithmetic mean surface roughness Sa was 0.15 μm.

[Production of fixing belt 7]
A tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer: Neoflon PFA (manufactured by Daikin Industries, Ltd.) was applied onto the elastic layer 1 and cured at 80° C. for 24 hours to prepare a fixing belt 7 having a surface layer 7 . The three-dimensional arithmetic mean surface roughness Sa was 0.42 μm.

[Production of fixing belt 8]
D-6600 (manufactured by Dow Toray Co., Ltd.), which is a bifunctional organosilane, is applied onto the elastic layer 1, cured at 80° C. for 5 minutes, and then dried at room temperature (25° C.) for 12 hours to form a surface layer 8. A fixing belt 8 was produced. The surface roughness Sa was 0.11 μm.

[Production of fixing belt 9]
Tetrabutoxysilane (manufactured by Tokyo Kasei Kogyo Co., Ltd.), which is a tetrafunctional organosilane, is dissolved in MEK at a volume ratio of 50% to silane, coated on the elastic layer 1, and dried at 80° C. for 1 hour. A fixing belt 8 having a surface layer 8 was produced by drying at room temperature (25° C.) for one week. The three-dimensional arithmetic mean surface roughness Sa was 0.11 μm.

"evaluation"
[Measurement of static friction coefficient]
The above static friction coefficient was measured as follows.
A flannel (cloth) was attached to the slider using a HEIDON (portable friction meter TYPE: 94i-II) manufactured by Shinto Scientific Co., Ltd. A measurement sample was placed on a glass plate (Tempax), and measured using the above measuring instrument at room temperature of 25°C.

[Measurement of three-dimensional arithmetic mean surface roughness Sa]
The three-dimensional arithmetic mean surface roughness Sa was measured by the method described above.

[Evaluation of Fixing Separability]
Fixing belts 1 to 9 produced above were installed as fixing belts of an electrophotographic image forming apparatus having a biaxial belt type fixing device. A roller constituting the fixing nip portion and supporting the fixing belt had a roller diameter of 60 mm. The surface temperature of each fixing belt is set to 180° C., and a toner image of a magenta band-shaped solid image having a width of 5 cm is transferred onto A4 size plain paper in the direction perpendicular to the conveying direction of the plain paper, and the plain paper is transferred. A fixed image of the band-shaped image was formed on the plain paper by passing it through the fixing nip portion in the longitudinal direction at 80 cpm, and evaluation of fixation separability was carried out by ranking in 5 stages according to the following evaluation criteria. In the case of poor fixing separability, the fixing member and the recording medium were partially adhered to each other, causing curling. A rank of 3 or higher was regarded as a pass.

Fixing Separability Rank 5 Separates without curling 4 Paper curls a little, but no problem Level 3 Paper curls, but not at a level that causes paper jams 2 About 1/3 of the leading edge of plain paper can be separated, but the rest No Separation in Machine, Jamming 1 All plain papers do not separate in the machine and cause paper jams. In the table, the three-dimensional arithmetic mean surface roughness Sa is simply abbreviated as "surface roughness Sa".

From Table I, it can be seen that the fixing belt, which is the fixing member of the present invention, is superior in fixing separability to the fixing belts of the comparative examples.

REFERENCE SIGNS LIST 10 fixing belt 1 base layer 2 elastic layer 3 release layer 100 main body of image forming apparatus 20 operation display section 21 operation display control section 22 LCD
30 scanner unit 301 paper feeding device 302 scanner 31 scanner control unit 32 CCD sensor d document 40 image forming unit 401 printer control unit 41 image forming unit 411 exposure unit 411a LD
412 Development Section 413 Photosensitive Drum 414 Charging Section 42 Intermediate Transfer Unit 421 Intermediate Transfer Belt 422 Primary Transfer Roller 423A Secondary Transfer Roller Up
423 Support roller 426 Belt cleaning unit 43 Secondary transfer unit 431A Secondary transfer roller Lw
431 Supporting roller 432 Secondary transfer belt 50, 50a, 50b Paper feeding section 51a, 51b, 51c Paper feeding tray unit S Paper 60 Fixing section 61 Fixing belt 62 Heating roller 63 Fixing roller 64 Pressure roller 65 Air separation section N Nip section 70 paper transport section 72 paper discharge section 72a paper discharge roller 73 transport path section 73a pair of registration rollers

Claims (5)

A fixing member used for fixing electrostatic latent image toner,
the fixing member has at least a base layer, an elastic layer and a surface layer;
a coefficient of static friction of the surface of the fixing member in an environment of 25° C. is in the range of 0.09 or more and less than 0.20;
The fixing member has a three-dimensional arithmetic mean surface roughness Sa in the range of 0.15 to 0.53 μm, and the surface layer is a condensate of siloxane having a structure represented by the following general formula (1). A fixing member comprising:

(In the formula, R ₁ represents a hydrocarbon group. _{X 1} , X ₂ and X ₃ each independently represent an alkyl group or an alkoxyalkyl group.) 2. The fixing member according to claim 1, wherein said fixing member has a three-dimensional arithmetic mean surface roughness Sa within a range of 0.15 to 0.3 μm. A fixing member used for fixing electrostatic latent image toner,
the fixing member has at least a base layer, an elastic layer and a surface layer;
a coefficient of static friction of the surface of the fixing member in an environment of 25° C. is in the range of 0.15 to 0.19;
The three-dimensional arithmetic mean surface roughness Sa of the fixing member is in the range of 0.33 to 0.53 μm, and
A fixing member, wherein the surface layer contains cyclohexyltrimethoxysilane, ethyltrimethoxysilane, or tris(2-methoxyethoxy)vinylsilane. A fixing member manufacturing method for manufacturing the fixing member according to any one of claims 1 to 3, comprising:
obtaining a mixture containing a siloxane having a structure represented by the general formula (1) and a solvent;
A method for manufacturing a fixing member, comprising: applying the mixture onto the elastic layer; and curing the applied mixture by heating or drying to form the surface layer. An image forming apparatus comprising the fixing member according to any one of claims 1 to 3.

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