JP2005215645A - Member for fixation, fixing device, image fixing method, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a member for fixation that can prevent toner from remaining and wax from remaining on a surface during long-period use, can suppress sticking of paper powder etc. on the surface, and further suppress modification of the surface due to a heat history to prevent occurrence of an image defect, a fixing device using the member for fixation, an image fixing method, and an image forming device. <P>SOLUTION: Disclosed are the member for fixation which includes a base layer and a surface layer provided on the base layer and abuts against an unfixed toner image carried on a recording medium to apply heat and pressure to the unfixed toner image, and is characterized in that the surface layer has a surface formed of a layer of fluorocarbon siloxane rubber in which inorganic particles are dispersed and the angle at which the surface comes into contact with dimethyl silicone oil at 25°C is ≤40°, the fixing device using the member for fixation, image fixing method, and image forming apparatus. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fixing member, a fixing device that fixes an undetermined toner image on a recording medium using the fixing member, an image fixing method, and an image forming apparatus.

2. Description of the Related Art Conventionally, image forming apparatuses such as copying machines and printers using electrophotographic technology are known.
In this electrophotographic image forming apparatus, an image is formed using a toner containing a binder resin, a colorant and the like. That is, in forming an image, first, an electrostatic latent image is formed on an image carrier based on an input signal. Next, the electrostatic latent image on the image carrier is developed by transferring the toner accommodated in the developing device to the image carrier to form a toner image on the image carrier. Further, the toner image formed on the image carrier is finally transferred and fixed on a predetermined recording medium to form an image composed of the fixing toner image on a recording medium such as paper.

  As a fixing method for fixing an unfixed toner image on a predetermined recording medium, a contact-type heating and pressurizing method in which the toner image on the recording medium is brought into contact with the recording medium to which the toner image is transferred and heat is applied. Various methods are known, such as a non-contact type heating method in which an oven is provided at a position away from the recording medium on which the toner image is transferred, and heat from the oven is used, but from the viewpoint of reliability and safety The contact type heating and pressurizing method is mainly used. As one of the fixing devices adopting the contact type heating and pressing method, a belt-like fixing member (hereinafter referred to as a fixing belt) is provided, and the surface of the fixing belt is brought into contact with an unfixed toner image on a recording medium. And a fixing device that heats an unfixed toner image to a temperature equal to or higher than the melting point of the toner to bring it into a molten state and pressurizes it, and finally peels the recording medium from the surface of the fixing belt.

In the fixing device including the fixing belt, when the recording medium is peeled off from the surface of the fixing belt, if the releasability between the surface and the toner image is poor, the image on the recording medium becomes incomplete, The toner remaining on the fixing belt may cause a bad influence on the subsequent image formation.
For this reason, in order to improve the releasability from the toner image on the surface of the fixing belt, the surface of the fixing belt is formed of fluorocarbon siloxane rubber (for example, see Patent Document 1) or the surface of the fixing belt is formed of silicone rubber. It has been known.
Japanese Patent No. 2903972

When the toner contains wax, when the toner is heated by the fixing belt, the wax often melts and adheres to the surface of the fixing belt before the toner binder resin. If it adheres to the surface of the fixing belt with good properties, the wax is difficult to peel off from the surface of the fixing belt and tends to remain. In addition, with use over many years, paper dust or the like adheres to the surface of the fixing belt, and further, modification due to thermal history occurs.
In the fixing device including the fixing belt, the surface property of the toner image fixed on the recording medium depends on the temperature at the separation point from the fixing belt and the surface shape of the fixing belt. In other words, the surface property of the fixed toner image peeled off at a temperature equal to or higher than the melting point of the toner depends on the viscoelasticity of the toner, and the surface property of the fixed toner image peeled off at a temperature lower than the melting point of the toner If the surface of the fixing belt is smooth and the surface of the fixing belt is smooth, the fixing toner image has a very high gloss, that is, a high gloss, but residual wax or paper dust adheres to the surface of the fixing belt. If the belt surface is modified by the thermal history, the gloss of the fixed toner image becomes low.

In the case of peeling from the fixing belt below the melting point of the toner, whether the fixing belt is made of fluorocarbon siloxane rubber or the fixing belt using silicone rubber, the surface described in Patent Document 1 is used for a long time. Although the adhesion of residual toner can be suppressed over the use of the toner, the adhesion of residual wax, paper powder, etc., or the modification due to the heat history cannot be suppressed. It goes down.
In addition, a method of applying a release agent such as silicone oil to the surface of the fixing belt is known in order to prevent deterioration of releasability due to deposits such as residual wax and paper powder. Due to the poor affinity, the release agent is repelled, and effective effects cannot be obtained. Image quality defects such as offset occur between the initial hundreds to thousands. End up.

  Therefore, in view of the above circumstances, the present invention prevents toner from remaining on the surface and wax from remaining on the surface over a long period of use, and suppresses paper dust and the like from adhering to the surface. Furthermore, the present invention provides a fixing member that can suppress surface modification due to thermal history and can prevent image defects, a fixing device using the fixing member, an image fixing method, and an image forming apparatus. This is the issue.

In order to solve the above problems, the present inventors have found the following present invention in order to achieve the above problems.
That is, the present invention
<1> For fixing that has a configuration including a base layer and a surface layer provided on the base layer, abuts against an unfixed toner image carried on a recording medium, and applies heat and pressure to the unfixed toner image A member,
For fixing, wherein the surface layer has a surface formed of a layer made of a fluorocarbon siloxane rubber in which inorganic particles are dispersed, and a contact angle of the surface with respect to dimethyl silicone oil at 25 ° C. is 40 degrees or less. It is a member.

<2> The mass average particle diameter of the inorganic particles is 0.5 μm or more and 15 μm or less, and the inorganic particles are contained in a ratio of 1 to 30% by mass in the layer made of the fluorocarbon siloxane rubber. The fixing member according to <1>.

<3> A mass average particle diameter of the inorganic particles is 0.5 μm or more and 10 μm or less, and particles having a particle diameter of 15 μm or more are 25% by mass or less of the whole particles <2 The fixing member according to>.

<4> The fixing member according to <2>, wherein the inorganic particles are contained in the layer made of the fluorocarbon siloxane rubber at a ratio of 5 to 25% by mass.

<5> The fixing member according to any one of <1> to <4>, wherein the inorganic particles are at least one selected from the group consisting of BaSO ₄ and zeolite.

<6> The fluorocarbon siloxane rubber according to any one of <1> to <5>, wherein the fluorocarbon siloxane rubber is a fluorocarbon siloxane rubber having a perfluoroalkyl ether group and / or a perfluoroalkyl group in the main chain. The fixing member described above.

<7> The surface layer is a laminate including a first rubber layer made of a fluorocarbonsiloxane rubber in which the inorganic particles are dispersed, and a second rubber layer made of silicone rubber provided thereunder. The fixing member according to any one of <1> to <6>, wherein:

<8> The fixing member according to <7>, wherein the second rubber layer is thicker than the first rubber layer.

<9> The fixing member according to any one of <1> to <8>, wherein the surface layer has a thickness of 300 μm or less.

<10> Any one of <1> to <9>, wherein the layer composed of the fluorocarbon siloxane rubber in which the inorganic particles are dispersed has a JIS A hardness based on JIS K 6253 of 5 degrees or more and 80 degrees or less. The fixing member according to Item 1.

<11> The fixing member according to any one of <1> to <10>,
A release agent supply device for supplying a release agent to the surface of the fixing member;
A fixing device.

<12> a fixing step of fixing an unfixed toner image on a recording medium using at least the fixing member according to any one of <1> to <10>;
A peeling step of peeling the recording medium from the surface of the fixing member;
A release agent supplying step of supplying a release agent to the surface of the fixing member;
And an image fixing method.

<13> At least a toner image forming unit that carries an unfixed toner image on a recording medium;
<1> to <10> The fixing member according to any one of
A release agent supply device for supplying a release agent to the surface of the fixing member;
An image forming apparatus comprising:

  According to the present invention, it is possible to prevent toner from remaining on the surface and wax from remaining on the surface over a long period of use, and to prevent paper dust and the like from adhering to the surface. It is possible to provide a fixing member that can suppress surface modification due to the history and prevent image defects, a fixing device using the fixing member, an image fixing method, and an image forming apparatus.

Hereinafter, the present invention will be described in detail.
<Fixing member>
First, the fixing member of the present invention will be described.
The fixing member of the present invention has a configuration including a base layer and a surface layer provided on the base layer, and is in contact with an unfixed toner image carried on a recording medium. A fixing member for applying pressure,
The surface layer has a surface formed of a layer made of a fluorocarbon siloxane rubber in which inorganic particles are dispersed, and a contact angle of the surface with respect to dimethyl silicone oil at 25 ° C. is 40 degrees or less.
As described above, the fixing member of the present invention has a configuration including at least two layers of a base layer and a surface layer, and the surface layer is further formed of a layer made of a fluorocarbon siloxane rubber in which inorganic particles are dispersed. Having a surface to be made.

Note that the fixing member of the present invention has the above-described layer structure, abuts against an unfixed toner image carried on a recording medium, and can apply heat and pressure to the unfixed toner image. For example, the form is not limited and may be, for example, a roll shape or a belt shape. Among these, a belt shape is preferable, and an endless belt is particularly preferable.
In the fixing member of the present invention, an arbitrary layer may be formed between the base layer and the surface layer.
Hereinafter, the base layer and the surface layer constituting the fixing member of the present invention will be described.

[Base layer]
The base layer in the present invention is required to have heat resistance and mechanical strength, and a metal sheet such as nickel, aluminum or stainless steel, or a resin film such as PET, PBT, polyimide or polyimide amide can be used. The resin may have a volume resistivity controlled by adding and dispersing conductive powder or the like. Specifically, for example, an endless belt-shaped polyimide belt in which volume resistivity is controlled by adding and dispersing carbon black can be used as the base layer. Furthermore, the base layer can be used by combining both ends of a long polyimide sheet on a puzzle, thermocompression bonding using a thermocompression bonding member, and making an endless belt.

  The thickness of the base layer is preferably in the range of 20 to 200 μm, more preferably in the range of 30 to 150 μm, and still more preferably in the range of 40 to 130 μm. When the thickness of the base layer is less than 20 μm, the dimensional stability during heating and cooling and the strength are insufficient. On the other hand, if it exceeds 200 μm, the specific heat of the fixing member increases and the amount of heat transfer decreases, leading to a decrease in transfer speed and cycle time.

[Surface layer]
The surface layer in the present invention has a surface formed of a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, and the contact angle of the surface with dimethyl silicone oil at 25 ° C. is 40 degrees or less. The contact angle is more preferably 30 degrees or less.
Thus, when the surface contact angle of the surface layer is 40 degrees or less, the affinity between the release agent dimethylsilicone oil and the surface of the fixing member is improved.

Here, as a method for measuring the surface contact angle, a conventionally known method can be used. The method for measuring the surface contact angle in the present invention is described below.
First, an evaluation sample in which a surface layer material of 30 to 200 μm is formed on an aluminum flat plate is prepared. Then, dimethyl silicone oil (manufactured by Toray Dow Corning Silicone Co., Ltd .: SH200 (100 cst)) is dropped onto the surface of the evaluation sample with a microsyringe so as to be approximately 5 ml, and this is added to a contact angle meter (FACE CA-X). Type: Kyowa Interface Science Co., Ltd.) In the present invention, the temperature at the time of measurement is 25 ° C., the contact angles are measured at five locations, and the average value of the five points obtained is the contact angle indicated by the evaluation sample and dimethyl silicone oil. It is used as the value of.

As a means for controlling the surface contact angle of the surface layer, it can be carried out by adjusting the composition of the layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, which forms the surface of the fixing member of the present invention.
Specifically, for example, the surface contact angle of the surface layer can be controlled to 40 degrees or less by adjusting the composition (type) of the fluorocarbon siloxane rubber, the type of inorganic particles, the particle diameter, the amount added, and the like.

As inorganic particles used in the present invention, BaSO ₄ , zeolite, tin oxide, aluminum oxide, copper oxide, iron oxide, zirconium oxide, ITO (tin-doped indium oxide), titanium dioxide, boron nitride, titanium nitride, calcium carbonate, It is preferably at least one selected from the group consisting of magnesium carbonate, mica, talc, sericite and bentonite, and more preferably at least one selected from the group consisting of BaSO ₄ and zeolite.

These inorganic particles can be used in the mass average particle diameter in the range of 10 nm to 15 μm, preferably 0.5 μm to 15 μm, more preferably 1 μm to 10 μm. It is below, More preferably, it is the range of 2 micrometers or more and 8 micrometers or less.
Among these, from the viewpoint of improving the formation of sharp protrusions on the surface, particles having a mass average particle diameter of 0.5 μm or more and 15 μm or less and having a particle diameter of 15 μm or more are 25% by mass of the whole particles. It is preferable that the average particle diameter is 1 μm or more and 10 μm or less, and the particle having a particle diameter of 15 μm or more is more preferably 5% by mass or less of the whole particle, and the particle diameter is 15 μm or more. It is more preferable that the particles having a content of 3% by mass or less of the entire particles.

Here, as a method for measuring the particle size of the inorganic particles, a conventionally known method can be used, and the method for measuring the particle size of the inorganic particles in the present invention is described below.
Dispersion prepared by using a laser diffraction particle size distribution analyzer LA-500 (manufactured by Horiba Seisakusho) and setting the amount of sample (inorganic particles) to be adjusted so that the transmittance of laser light is 65 to 85%. From this, the particle diameter of the inorganic particles is measured.
As the dispersion medium, ion-exchanged water, sodium hexametaphosphate aqueous solution (0.2%), neutral surfactant aqueous solution (0.5% main component: sodium alkyl ether sulfate ester, fatty acid alkanolamide), ethanol, glycerin The aqueous solution (50%) is selected according to the inorganic particles to be measured.

  Furthermore, the inorganic particles are preferably contained in the layer composed of the fluorocarbon siloxane rubber in a proportion of 1 to 30% by mass, and more preferably in a proportion of 2 to 50% by mass. When the content of the inorganic particles is less than 1% by mass, the surface contact angle cannot be adjusted, and the effect of improving the affinity between the release agent such as dimethyl silicone oil and the surface of the fixing member is not exhibited. Moreover, when content exceeds 50 mass%, it will thicken and it will become difficult to disperse | distribute in a layer.

  The fluorocarbon siloxane rubber used in the present invention preferably has a perfluoroalkyl ether group and / or a perfluoroalkyl group in the main chain.

In the present invention, it is preferable that the layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed is a layer having the following constitution.
That is, a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed,
(A) a fluorocarbon polymer having a main component of a fluorocarbonsiloxane of the following general formula (1) and having an aliphatic unsaturated group;
(B) The molecule contains 2 or more ≡SiH groups, and the content of the ≡SiH groups is 1 to 4 times the molar amount of the aliphatic unsaturated groups in the fluorocarbon siloxane rubber composition. Certain organopolysiloxanes and / or fluorocarbon siloxanes,
(C) a filler,
(D) an effective amount of catalyst, and
(E) It is more preferably composed of a cured product of a fluorocarbon siloxane rubber precursor composition containing inorganic particles.

  In this case, the fluorocarbon polymer of the component (A) is mainly composed of a fluorocarbon siloxane having a repeating unit represented by the following general formula (1) and has an aliphatic unsaturated group. This aliphatic unsaturated group is a monovalent aliphatic unsaturated hydrocarbon group, preferably having 2 to 3 carbon atoms, and specifically, having 2 to 3 carbon atoms such as vinyl, allyl, and ethynyl groups. An alkenyl group of 3 is mentioned as an example, and a vinyl group is particularly preferable. In this case, the aliphatic unsaturated group is preferably at the end of the molecular chain. For example, the aliphatic unsaturated group preferably has a vinyl dialkylsilyl group, a divinylalkylsilyl group, or a trivinylsilyl group in the main chain. In addition, as an alkyl group of these groups, those having 1 to 8 carbon atoms are preferable, and a methyl group is particularly preferable.

Here, in the above formula (1), R ¹⁰ represents an unsubstituted or substituted preferably monovalent hydrocarbon group having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms or 2 to 2 carbon atoms. 3 alkenyl group, particularly preferably a methyl group. a and e each independently represent 0 or 1; b and d each independently represents an integer of 1 to 4; and c represents an integer of 0 to 8. X represents an integer of 1 or more, preferably an integer of 10 to 30.
Specific examples of such component (A) include those represented by the following formula (2).

The component (B) contains two or more ≡SiH groups in one molecule, and this ≡SiH group is 1 to 4 times the amount of aliphatic unsaturated groups in the fluorocarbon siloxane rubber precursor composition. Some organopolysiloxanes and / or fluorocarbons.
Here, examples of the organopolysiloxane having an ≡SiH group include organohydrogenpolysiloxane having at least two hydrogen atoms bonded to a silicon atom in the molecule.

  In the fluorocarbon siloxane rubber precursor composition, since the fluorocarbon polymer as the component (A) has an aliphatic unsaturated group, the above-described organohydrogenpolysiloxane can be used as a curing agent. That is, in this case, a cured product is formed by an addition reaction that occurs between an aliphatic unsaturated group in the fluorocarbon siloxane and a hydrogen atom bonded to a silicon atom in the organohydrogenpolysiloxane. As such organohydrogenpolysiloxanes, various organohydrogenpolysiloxanes used in addition-curing silicone rubber compositions can be used. Particularly, the following (α) and (β) Are preferably used.

(Α) Organohydrogenpolysiloxane represented by the following formulas (3) to (5).

In the above formulas (3) to (5), s and t represent an integer of 0 or more, and u represents an integer of 2 or more. R ² represents an unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, specifically, Alkyl groups such as methyl, ethyl, isopropyl and butyl; cycloalkyl groups such as cyclohexyl and cyclopentyl; aryl groups such as phenyl, tolyl and xylyl; aralkyl groups such as benzyl and phenylethyl And halogenated hydrocarbon groups such as chloromethyl group, chloropropyl group, chlorocyclohexyl group, 3,3,3-trifluoropropyl group, and cyano hydrocarbon groups such as 2-cyanoethyl group. Of these, a methyl group, an ethyl group, a phenyl group, and a 3,3,3-trifluoropropyl group are particularly preferable. R ⁴ represents a divalent group interposed between the silicon atom and the fluorine-containing organic group R _f, and is a divalent hydrocarbon group having no aliphatic unsaturated bond or a general formula —R ⁵ —O—R ^6. A divalent hydrocarbon group having an ether group represented by-(wherein R ⁵ and R ⁶ are a divalent hydrocarbon group having no aliphatic unsaturated bond), Eight is preferred. Specific examples include the following.

Among R ⁴ , particularly preferred groups are —CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —, and —CH ₂ CH ₂ CH ₂ —O—CH ₂ —. R _f represents a perfluoroalkyl group or a perfluoroalkyl ether group. Examples of the perfluoroalkyl group include those represented by the formula C _p F _{2p + 1} — (wherein p is an integer of 4 to 10), and particularly preferred groups are C ₆ F ₁₃ —, C _8. F _17- , C ₁₀ F _21- . As the perfluoroalkyl ether group, those having 5 to 15 carbon atoms are particularly preferable, and specific examples thereof include the following.

(Β) A copolymer comprising (CH ₃ ) ₂ HSiO _0.5 units and SiO ₂ units represented by the following formula (6).

  The viscosity of these organohydrogenpolysiloxanes at 25 ° C. is usually preferably 20 Pa · s or less. The above-mentioned organohydrogenpolysiloxane generally has at least one ≡SiH group, particularly 1 to 5 with respect to one aliphatic unsaturated hydrocarbon group in the fluorocarbon siloxane of component (A). It is suitable to mix | blend in such a ratio.

In addition, the fluorocarbon having an ≡SiH group includes a unit of the above formula (1) or a SiH such as R ¹⁰ in the formula (1) having a dialkylhydrogensiloxy group and a terminal having a dialkylhydrogensiloxy group or a silyl group. What is a group is preferable, and specific examples thereof include those represented by the following formula (7).

  As the filler of the component (C), various fillers used in general silicone rubber compositions can be used. For example, fumed silica, precipitated silica, carbon powder, titanium dioxide, aluminum oxide, quartz powder, reinforcing fillers such as talc, sericite and bentonite, fibrous fillers such as asbestos, glass fiber, organic fiber, etc. It can be illustrated. These fillers are preferably blended in an amount of 10 to 300 parts, particularly 20 to 200 parts, per 100 parts (A) component (parts by mass). When the blending amount of the filler is less than 10 parts, a sufficient reinforcing effect cannot be obtained, and when blended in a proportion exceeding 300 parts, the mechanical strength of the cured product is reduced. There is a risk of inconvenience.

As the catalyst of the component (D), chloroplatinic acid, alcohol-modified chloroplatinic acid, complexes of chloroplatinic acid and olefin, platinum black or palladium, which are known as addition reaction catalysts, alumina, silica, carbon, etc. Examples are those supported on the above-mentioned carrier, complex of rhodium and olefin, group VIII element of periodic table such as chlorotris (triphenylphosphine) rhodium (Wilkinson catalyst), rhodium (III) acetylacetonate, etc. However, these complexes are preferably used by being dissolved in a solvent such as an alcohol, ether, or hydrocarbon.
The compounding amount of these platinum group metal catalysts may be an effective amount of the catalyst, but is usually 1 to 500 ppm, particularly 5 to 20 ppm in terms of platinum group metal with respect to 100 parts of component (A). It is preferable to use it.

As the inorganic particles of the component (E), those described as inorganic particles dispersed in the layer made of the above-mentioned fluorocarbon siloxane rubber are used. The blending amount of the inorganic particles is the same as described above.
In addition, this inorganic particle has a larger particle diameter than the normal filler used as said (C) component. Therefore, the surface of the layer made of fluorocarbon siloxane rubber in which the inorganic particles are dispersed covers the surface of the inorganic particles existing on the extreme surface when such inorganic particles are exposed or are initially used. It appears that the fluorocarbon siloxane layer is destroyed and such inorganic particles are exposed. Thereby, it is estimated that the affinity between the surface layer surface and the release agent can be greatly improved.

  In such a fluorocarbon siloxane rubber precursor composition, various compounding agents can be added as long as the solvent resistance is not impaired. For example, diphenylsilane diol, low-polymerization degree molecular chain terminal hydroxyl-blocked dimethylpolysiloxane, dispersant such as hexamethyldisilazane, heat resistance improver such as ferrous oxide, ferric oxide, cerium oxide, iron octylate Further, colorants such as pigments can be blended as necessary.

  The thickness of the surface layer is preferably 300 μm or less, more preferably in the range of 1 to 300 μm, still more preferably in the range of 5 to 200 μm, and particularly preferably in the range of 10 to 100 μm. If the thickness is less than 1 μm, the elasticity is insufficient and the effect of adding a rubber layer is lost, which may cause a problem in fixability or insufficient durability. If it exceeds 300 μm, the specific heat of the belt-shaped fixing member increases, the amount of heat transfer decreases, leading to a decrease in transfer speed and cycle time.

Further, the hardness of the layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed in the surface layer is determined according to JIS A hardness (JIS K 6253 “Testing method for hardness of added rubber and thermoplastic rubber”). (Hardness measured by ASKER A type) is preferably in the range of 5 degrees to 80 degrees, more preferably in the range of 10 degrees to 70 degrees, and still more preferably in the range of 20 degrees to 60 degrees. The range is suitable. When the hardness is less than 5 degrees, the strength is lowered and there is a problem in durability. On the other hand, when the hardness exceeds 80 degrees, the rigidity becomes too high regardless of the thickness of the surface layer, the adhesion between the fixing member and the recording medium decreases, and the cooling member (in the fixing device shown in FIG. 5 described later). Cooling by the heat sink 26 for cooling) is incomplete and peeling occurs, causing a problem that appears as a defect in image quality.
In addition, when the surface layer is formed only from a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, the preferable hardness range is a preferable hardness range of the surface layer.

  Furthermore, it is also preferable that the surface layer is a laminate comprising a first rubber layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed and a second rubber layer made of silicone rubber provided thereunder. It is. Thus, by setting it as the aspect which has a 2nd rubber layer, it becomes easy to change the rubber hardness of the whole surface layer. In particular, it is easy to lower (soften) the rubber hardness of the surface layer, so that the surface layer is given sufficient elasticity, and it is possible to improve the fixing property and durability.

Thus, when a surface layer is a laminated body, it is preferable that the thickness of a 2nd rubber layer is thicker than a 1st rubber layer from viewpoints, such as heat resistance. That is, when the surface layer is composed of two layers, the film thickness of the lower layer (the layer on the base layer side with respect to the outermost surface layer, here, the second rubber layer) is the upper layer (the layer on the outermost surface layer side, Here, it is preferable that it is thicker than the film thickness of the first rubber layer).
The combined thickness of the first rubber layer and the second rubber layer is preferably 300 μm or less, more preferably 1 to 300 μm, and still more preferably 5 to 200 μm from the viewpoint of heat resistance and the like. Particularly preferably, a range of 10 to 100 μm is suitable.

Hereinafter, various embodiments of the layer structure of the fixing member of the present invention will be described in more detail with reference to the drawings.
Note that the base layer and the surface layer used in the first to fourth embodiments are the same as those described above, and thus the details are omitted.

[First Embodiment]
First, a first embodiment of the fixing member of the present invention will be described. FIG. 1 is a schematic cross-sectional view of the main part showing the layer structure in the first embodiment of the fixing member of the present invention.
As shown in FIG. 1, the fixing member 10 a has a two-layer structure of a base layer 12 and a first rubber layer 14.
Here, the first rubber layer 14 is formed on the surface of the base layer 12 and forms the surface of the fixing member 10a. In the fixing member 10a shown in FIG. 1, the first rubber layer 14 is a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, and corresponds to an example of a surface layer in the present invention.
In the present invention, such a surface layer is required to have a surface contact angle with dimethyl silicone oil at 25 ° C. of 40 degrees or less. That is, in the first practical form, it means that the surface contact angle with respect to dimethyl silicone oil at 25 ° C. of the first rubber layer 14 which is a layer made of fluorocarbonsiloxane rubber in which inorganic particles are dispersed is 40 degrees or less. To do.

  As a method for forming the first rubber layer 14 corresponding to the surface layer of the present invention, an inorganic particle-containing fluorocarbon siloxane rubber precursor composition prepared with a predetermined composition is applied and cured on the surface of the base layer 12. A method is mentioned. As coating methods here, conventional methods such as blade coating method, wire bar coating method, ring coating method, spray coating method, dip coating method, flow coating method, bead coating method, air knife coating method, curtain coating method, etc. Can be used. Among these, the dip coating method is advantageous and particularly preferable in terms of seamless coating, mass productivity, cost, uniformity of layer thickness, and the like.

If necessary, the inorganic particle-containing fluorocarbonsiloxane rubber precursor composition may be diluted with a solvent such as m-xylene hexafluoride, perfluoroalkane, perfluoro (2-butyltetrahydrofuran), benzotrifluoride, or the like. A coating solution having an appropriate viscosity can be prepared and applied.
Further, as the inorganic particle-containing fluorocarbon siloxane rubber precursor composition, the supply form can be arbitrarily selected from one-part type, two-part type, the polymerization form, addition type, condensation type and the like.

Here, in the inorganic particle-containing fluorocarbonsiloxane rubber precursor composition to be applied, the inorganic particles are dispersed. As a method for dispersing the inorganic particles, a conventionally known dispersion method is used. For example, a ball mill dispersion method is used. Other dispersing methods include those using an attritor, sand mill, dyno mill, homogenizer, and the like.
Furthermore, a dispersion liquid can be produced by producing a suspension of perfluoroalkane used as a diluting solvent only with inorganic particles using a dispersion method such as a homogenizer and mixing and stirring with a fluorocarbon siloxane rubber precursor liquid. .
By adjusting the relationship between the viscosity of the fluorocarbon siloxane rubber precursor composition and the particle size and addition amount of inorganic particles, the inorganic particles do not precipitate in the inorganic particle-containing fluorocarbon siloxane rubber precursor composition. , A dispersed state can be formed.

Subsequently, the second to fourth embodiments of the fixing member of the present invention will be described with reference to the drawings.
[Second Embodiment]
Here, FIG. 2 is a schematic cross-sectional view of the main part showing the layer structure in the second embodiment of the fixing member of the present invention.
The fixing member 10b shown in FIG. 2 has a second rubber layer 16 between the base layer 12 and the first rubber layer 14 described above. The second rubber layer 16 is a layer formed on the surface of the base layer 12, and as the material of the second rubber layer 16, silicone rubber which is a material excellent in adhesiveness with the base layer 12 is used. ing. Further, the first rubber layer 14 is formed on the surface of the second rubber layer 16. Since the second rubber layer 16 is made of silicone rubber, the first rubber layer 14 and the second rubber layer are formed. Adhesiveness between 16 is also good. In the fixing member 10b shown in FIG. 2, the first rubber layer 14 is a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, and the first rubber layer 14 and the second rubber layer 16 are combined. Corresponds to an example of the surface layer according to the present invention, and also corresponds to an example of the surface layer being a laminate.

  The silicone rubber used for the second rubber layer 16 is not particularly limited, and examples thereof include dimethyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl silicone rubber, and fluoro silicone rubber. These silicone rubbers may be heat vulcanized (HTV) or room temperature cured (RTV). The polymerization form may be either an addition type or a condensation type.

As a method for forming the second rubber layer 16, the same application method as that for the first rubber layer 14 is used. That is, it can be obtained by applying and curing the prepared silicone rubber precursor composition on the surface of the base layer 12. The application method is the same as the application method of the first rubber layer 14 by the dip coating method. A usual method such as can be used.
Moreover, with respect to a silicone rubber precursor composition, if necessary, it can dilute with solvents, such as hexane, heptane, cyclohexane, toluene, xylene, and can prepare and apply | coat the coating liquid of suitable viscosity.
In addition, as the silicone rubber precursor composition, the supply form may be arbitrarily selected from the one-part type, the two-part type, the polymerization form, the addition type, the condensation type, and the like.

  The thickness of the second rubber layer 16 shown in FIG. 2 is preferably thicker than the thickness of the first rubber layer 14. That is, when the surface layer is composed of a plurality of layers, the lower layer (the layer on the base layer side with respect to the outermost surface layer) is thicker than the upper layer (the layer on the outermost surface layer side). From the viewpoint of heat resistance and the like. The total thickness of the first rubber layer 14 and the second rubber layer 16 is preferably 300 μm or less, more preferably in the range of 1 to 300 μm, still more preferably in the range of 5 to 200 μm, and particularly preferably 10. A range of ˜100 μm is suitable.

  In the second actual form, the first rubber layer 14 is formed on the surface of the second rubber layer 16 thus formed. In this case, the first rubber layer 14 is formed by applying and curing a fluorocarbonsiloxane rubber precursor composition on the surface of the second rubber layer 16 in the same manner as the first rubber layer 14 in the first embodiment. It is formed.

[Third Embodiment]
Here, FIG. 3 is a schematic cross-sectional view of the main part showing the layer structure in the third embodiment of the fixing member of the present invention.
The fixing member 10c shown in FIG. 3 has an adhesive layer 18 between the base layer 12 and the first rubber layer 14 described above. The adhesive layer 18 is a layer formed on the surface of the base layer 12, and the first rubber layer 14 is formed on the surface of the adhesive layer 18. In the third embodiment, since the adhesive layer 18 is provided, a material inferior in self-adhesiveness may be used as the material of the first rubber layer 14. In the fixing member 10c shown in FIG. 3, the first rubber layer 14 is a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, and corresponds to an example of a surface layer in the present invention.

  As the adhesive layer 18, primers or the like usually used for adhesion of silicone rubber can be applied. Examples of the primers include, but are not limited to, aminosilane coupling agents, chlorosilane coupling agents, chloromethylsilane coupling agents, cyanosilane coupling agents, titanate coupling agents, and the like. It is not something. Of these, aminosilane coupling agents and titanate coupling agents are preferably used. Furthermore, a primer designed for a fluorocarbon siloxane rubber is also preferably used.

  As a method for forming the adhesive layer 18, as a simple method, a method in which the surface of the base layer 12 is coated with a rag impregnated with a primer, a method for forming the adhesive layer 18 with higher accuracy, spray coating, dip coating, etc. Can be mentioned.

  In the third practical form, the first rubber layer 14 is formed on the surface of the adhesive layer 18 thus formed. The first rubber layer 14 at this time is formed by applying and curing a fluorocarbon siloxane rubber precursor composition on the surface of the adhesive layer 18, as in the first rubber layer 14 in the first embodiment. .

[Fourth Embodiment]
Here, FIG. 4 is a schematic cross-sectional view of the main part showing the layer structure in the fourth embodiment of the fixing member of the present invention.
The fixing member 10d shown in FIG. 4 includes the base layer 12, the adhesive layer 18, the second rubber layer 16, and the first member described in detail in the description of the fixing member according to the first to third embodiments. One rubber layer 14 is laminated in this order of description. In the fixing member 10d shown in FIG. 4, like the fixing member 10b shown in FIG. 2, the first rubber layer 14 is a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, and the first rubber layer The combination of 14 and the second rubber layer 16 corresponds to an example of the surface layer according to the present invention and also corresponds to an example of a laminate.

  In the fixing members from the first embodiment to the fourth embodiment described above, the surface is formed of the first rubber layer 14, that is, a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed. Has been. The surface of the first rubber layer 14 has a surface contact angle with dimethyl silicone oil at 25 ° C. of 40 degrees or less. For this reason, the wettability of the release agent (for example, dimethyl silicone oil) with respect to the fluorocarbon siloxane rubber is improved, and as a result, the affinity between the fixing member of the present invention and the release agent is improved. Therefore, it is effective to interpose the release agent between the unfixed toner image carried on the recording medium and the fixing member of the present invention, and the wax remains on the surface of the fixing member over a long period of use. Therefore, it is possible to prevent the surface property of the fixing member from being changed due to paper powder, toner external additives, etc. adhering cleanly. Further, due to the presence of a release agent such as dimethyl silicone oil with good affinity on the surface of the fixing member of the present invention, wax, toner, paper dust, which has been a conventional problem, due to the surface adhesiveness of the rubber elastic body. Adheres to and accumulates on the surface, and due to thermal history, the fusing member surface is covered by melting and integration, and the paper peeling characteristics are significantly deteriorated, and the gloss uniformity of the image surface is lost. It becomes possible to suppress.

  As described above, the surface of the fixing member of the present invention has a contact angle with dimethyl silicone oil at 25 ° C. of 40 degrees or less. Since the fixing member of the present invention having such a surface contact angle has improved affinity for a release agent other than dimethyl silicone oil, the above effect can be obtained. Examples of release agents other than dimethyl silicone oil include conventionally known silicones such as methylphenyl silicone oil, methyl hydrogen silicone oil, amine-modified silicone oil, mercapto-modified silicone oil, carboxy-modified silicone oil, and sulfonic acid-modified silicone oil. Oil can be mentioned. Among these, dimethyl silicone oil is preferable from the viewpoint of the adhesiveness of the tape to the printed paper (recording medium).

<Fixing device>
Next, a fixing device including the above-described fixing member of the present invention (fixing device of the present invention) will be described with reference to the drawings.
A fixing device according to the present invention includes at least the above-described fixing member according to the present invention and a release agent supply device that supplies a release agent to the surface of the fixing member.

Here, FIG. 5 is a schematic configuration diagram illustrating an exemplary aspect of the fixing device of the present invention.
A fixing device 20 shown in FIG. 5 includes a fixing belt 24 that is rotatably supported by three rolls including a heating roll 21, a peeling roll 22, and a walk control roll 23, and a fixing belt 24. And a pressure roll 25 that is in pressure contact with the heating roll 21. The fixing belt 24 includes a cooling heat sink 26 that forcibly cools the fixing belt 24 while the heating roll 21 and the peeling roll 22 are provided on the back side. The surface of the fixing belt 24 is cooled to a range of 50 ° C. to 80 ° C. near the peeling roll 22 by the cooling heat sink 26. The fixing device 20 is also provided with a small-diameter tension roll 27 that applies a certain tension to the fixing belt 24 between the cooling heat sink 26 and the heating roll 21. Further, the fixing device 20 is also provided with a cleaning roll 28 for removing residual toner and the like on the fixing belt 24. Here, the fixing belt 24 constituting the fixing device 20 is the fixing member of the present invention having an endless belt shape.
Further, the fixing device of the present invention includes a release agent supply device (not shown in FIG. 5) for supplying a release agent to the surface of the fixing member.

  The heating roll 21 is made of, for example, a silicone rubber having a JIS A hardness measured based on JIS K 6253 on the surface of a metal core made of aluminum, stainless steel, or the like, preferably in the range of 20 to 60 degrees. The elastic layer is preferably coated with a thickness in the range of 1 mm to 3 mm, and the surface of the elastic layer is further coated with a release layer composed of a PFA tube or the like to form a predetermined outer diameter. It is done. Inside the heating roll 21, a halogen lamp (not shown) having a calorific value in the range of 300 to 350 W is disposed as a heating source. By this halogen lamp, the surface of the heating roll 21 is heated from the inside so as to have a predetermined temperature (preferably in a range of 130 to 195 ° C.).

  Moreover, as the pressure roll 25, what was comprised similarly to the heating roll 21, for example is used, and the JIS A hardness measured based on JIS K 6253 on the surface of the metal core which consists of aluminum, stainless steel, etc., An elastic body layer made of silicone rubber or the like, preferably in the range of 20 degrees to 60 degrees, is coated with a thickness of preferably 1 mm to 3 mm, and a mold release made of a PFA tube or the like on the surface of the elastic body layer. A layer formed by covering the layer and having a predetermined outer diameter is used. Also inside the pressure roll 25, a halogen lamp having a calorific value, preferably in the range of 300W to 350W, is disposed as a heating source. By this halogen lamp, the surface of the pressure roll 25 is heated from the inside so as to have a predetermined temperature (preferably in a range of 85 ° C. to 155 ° C.). In this pressure roll 25, a heating source may be omitted.

  As described above, the fixing belt 24 is stretched around the three rolls including the heating roll 21, the peeling roll 22, and the walk control roll 23, and is rotationally driven by a driving source (not shown). The heating roll 21 circulates counterclockwise in FIG. 5 at a predetermined moving speed. A release agent supply device that supplies a release agent (dimethyl silicone oil) to the surface of the fixing belt 24 is provided at a position close to the fixing belt 24.

  The heating roll 21 and the pressure roll 25 are configured so as to come into pressure contact with each other, preferably in a range of 100 kPa to 200 kPa, by a pressure unit (not shown) via the fixing belt 24, thereby forming a nip region N. ing.

<Image fixing method>
Next, an image fixing method using the above-described fixing member of the present invention (image fixing method of the present invention) will be described with reference to the drawings.
The image fixing method of the present invention includes at least a fixing step of fixing an unfixed toner image on a recording medium using the above-described fixing member of the present invention, and a peeling step of peeling the recording medium from the surface of the fixing member. And a release agent supplying step for supplying a release agent to the surface of the fixing member.

The image fixing method of the present invention will be described with reference to FIGS.
Here, FIG. 6 is a flowchart showing each step of the image fixing method performed in the exemplary embodiment of the fixing device of the present invention shown in FIG.
The image fixing method implemented in the fixing device 20 shown in FIG. 5 includes a pressure heating step S11, a cooling step S12, and a peeling step S13, and further, a release agent supply step (not shown in FIG. 6). Have
The paper (recording medium) P to which the toner image T is transferred passes through the nip region N shown in FIG. 5 from the left to the right in FIG. At this time, the paper P is introduced into the nip region N so that the toner image T is positioned on the heating roll 21 side, that is, in contact with the surface of the fixing belt 24.

In the heating and pressing step S11 shown in FIG. 6, the surface of the fixing belt 24 is brought into contact with the paper P carrying the unfixed toner image T shown in FIG. 5, and heat and pressure are applied to the unfixed toner image. That is, the paper P introduced into the nip region N is sandwiched between the surface of the fixing belt 24 and the surface of the pressure roll 25, and the toner image on the paper P is pressed by the surface of the fixing belt 24. The Further, the surface of the fixing belt 24 is heated by the heating roll 21, and the toner image on the paper P introduced into the nip region N is heated by the surface of the fixing belt 24. Furthermore, since the surface of the pressure roll 25 shown in FIG. 5 is also heated, the toner image on the paper P is also heated from the back side. The toner constituting the toner image T heated in such a pressurized state is in a molten state while the paper P passes through the nip region N.
A fixed tension is applied to the fixing belt 24 by a tension roll 27, and the paper P that has passed through the nip region N is conveyed by the circulating fixing belt 24 in close contact with the surface of the fixing belt 24. .

  In the cooling step S12 performed subsequent to the heating and pressing step S11, the heated unfixed toner image is cooled by performing the pressing and heating step S11. That is, the portion of the circulating fixing belt 24 that passes through the region where the cooling heat sink 26 is provided is forcibly cooled by the heat sink 26, so that the melted toner is cooled by the surface of the fixing belt 24. Solidify. Further, the stiffness of the paper P is recovered by this cooling. The paper P that is in close contact with the fixing belt 24 recovers its stiffness, the toner on the paper P is solidified, and further, due to the influence of the change in the curvature of the fixing belt 24 by the peeling roll 22, the peeling roll 22 The fixing belt 24 is easily peeled off from the surface.

  In a peeling step S13 performed subsequent to the cooling step S12, the paper P that has been in contact with the surface of the fixing belt 24 is peeled off from the surface. That is, the paper P that has reached the peeling roll 22 is peeled off from the surface of the fixing belt 24. A toner image is fixed on the paper P peeled off from the surface of the fixing belt 24. On the other hand, residual toner and the like are removed from the surface of the fixing belt 24 from which the paper P has been peeled off by the cleaner roll 28, and prepare for the next fixing process.

Here, in the image fixing method of the present invention, a release agent supply step using a release agent supply device that supplies a release agent (dimethyl silicone oil) to the surface of the fixing belt 24 is essential.
As an example of the release agent supply device, a member having a silicone rubber layer formed on a metal roll is impregnated with a release agent such as dimethyl silicone oil, and the member is brought into direct or indirect contact with the surface of the fixing belt 24. In addition, those that can control the supply amount of the release agent, such as those in which a web impregnated with a release agent such as dimethyl silicone oil is brought into direct or indirect contact with the surface of the fixing belt 24, are excellently used. Is done.
In the fixing device and the image fixing method of the present invention, the release agent used in the release agent supply device and the release agent supply step is not only dimethyl silicone oil, but also methylphenyl silicone oil, methyl hydrogen silicone. Conventionally known silicone oils such as oil, amine-modified silicone oil, mercapto-modified silicone oil, carboxy-modified silicone oil, and sulfonic acid-modified silicone oil can be exemplified.

  As described above, according to the fixing device and the image fixing method of the present invention, the fixing member of the present invention is used, and the above-mentioned release agent supply device and release agent supply step are further provided. The unfixed toner image carried on the recording medium is fixed satisfactorily, and as a result, a good quality fixed toner image can be formed.

<Image forming apparatus>
Hereinafter, an image forming apparatus (an image forming apparatus of the present invention) provided with the above-described fixing member of the present invention will be described with reference to the drawings.
The image forming apparatus according to the present invention includes at least a toner image forming unit that carries an unfixed toner image on a recording medium, the above-described fixing member according to the present invention, and a release agent that supplies a release agent to the surface of the fixing member. And a mold supply device.

(First Embodiment of Image Forming Apparatus of the Present Invention)
Here, FIG. 7 is a schematic configuration diagram showing a full-color image forming apparatus which is the first embodiment of the image forming apparatus of the present invention.
The image forming apparatus 1 shown in FIG. 7 includes the fixing device 20 of the present invention shown in FIG. 5, a photosensitive drum 110, an intermediate transfer belt 120, a primary transfer roll 130, a developing rotary 140, and a bias roll. 150 and a backup roll 160, and includes a toner image forming unit 100 for carrying an unfixed toner image on a recording medium.

  The photosensitive drum 110 rotates clockwise. The intermediate transfer belt 120 is arranged so as to be stretched between a plurality of support rolls and brought into contact with the surface of the photosensitive drum 110. In the image forming apparatus 1, a primary transfer roll 130 is disposed at a position facing the photosensitive drum 110 with the intermediate transfer belt 120 interposed therebetween. The portion where the photosensitive drum 110 and the intermediate transfer belt 120 are in contact is the primary transfer position.

  A developing rotary 140 is disposed around the photosensitive drum 1 on the upstream side of the primary transfer position. The developing rotary 140 is provided with a developing unit (not shown) that stores colored toners of black (BK), yellow (Y), magenta (M), and cyan (C). Further, on the upstream side of the developing roll 40, although not shown, a charger is disposed. Although not shown, a charger, an optical writing unit, a cleaning device, and a charge eliminating device are disposed around the photosensitive drum 1.

  A bias roll 150 as a secondary transfer member is provided around the intermediate transfer belt 120 on the downstream side of the primary transfer position. Further, at a position facing the bias roll 150 with the intermediate transfer belt 120 interposed therebetween, A backup roll 160 is provided. In this image forming apparatus 1, the position sandwiched between the bias roll 150 and the backup roll 160 is the secondary transfer position, and the secondary transfer position includes a paper feed tray group 170 that accommodates each size of paper. The supplied paper, the paper on which the manual feed stand 180 is placed, the OHP sheet, or the like is sent.

Here, a method for carrying an unfixed toner image on a recording medium in the toner image forming unit 100 of the image forming apparatus 1 shown in FIG. 7 will be described.
The image forming apparatus 1 shown in FIG. 7 receives image signals of four colors of yellow, magenta, cyan, and black. When these image signals are input, in the image forming apparatus 1, the surface of the photosensitive drum 110 is uniformly charged by a charger, and then, according to the cyan image signal in the input image information. Then, an electrostatic latent image is formed on the surface of the photosensitive drum 110 by irradiating the photosensitive drum 110 with laser light from the optical writing unit. Subsequently, the electrostatic latent image formed on the surface of the photoconductive drum 110 is developed by a developing unit that contains cyan toner provided in the developing rotary 140 to form a cyan toner image on the surface of the photoconductive drum 110. . Next, the cyan toner image on the photosensitive drum 110 is primarily transferred to the intermediate transfer belt at the primary transfer position. From the surface of the photosensitive drum 110 after the primary transfer of the cyan toner image to the intermediate transfer belt 120, the residual toner is removed by the cleaning device, and the residual charge is removed by the static eliminator.

Subsequently, a magenta toner image is formed in the same manner on the surface of the photosensitive drum 110, and this magenta toner image is primarily transferred to the intermediate transfer belt 120 first at the primary transfer position. Primary transfer is performed on the intermediate transfer belt 120 so as to overlap the image.
Thereafter, a cyan toner image and a black toner image are sequentially formed, and primary transfer is sequentially performed at the primary transfer position so as to overlap with the toner image previously transferred to the intermediate transfer belt 120. By doing so, a toner image is formed on the intermediate transfer belt 120 so as to overlap one another in the order of cyan, magenta, yellow, and black from the belt surface side.
Then, the toner images overlapped with each other are secondarily transferred onto a sheet (recording medium) at a secondary transfer position sandwiched between the bias roll 150 and the backup roll 160. Thus, the unfixed toner image is carried on the paper.

  The sheet carrying the unfixed toner image is sent to the fixing device 20 of the present invention. In the fixing device 20, by passing a sheet carrying an unfixed toner image through a predetermined nip region, heat and pressure are applied to the unfixed toner image to fix the unfixed toner image on the sheet. The sheet on which the toner image is fixed is discharged to a discharge tray 190 provided in the image forming apparatus 1.

(Second Embodiment of Image Forming Apparatus of the Present Invention)
Next, a second aspect of the image forming apparatus of the present invention will be described.
Here, FIG. 8 is a schematic configuration diagram showing a second aspect of the image forming apparatus of the present invention.
The configuration of the toner image forming apparatus (toner image forming unit) 200 shown in FIG. 8 is slightly different from the configuration of the toner image forming unit 100 in the image forming apparatus 1 shown in FIG. Hereinafter, only this different part will be described, and redundant description will be omitted.

  The toner image forming apparatus 200 shown on the left side of FIG. 8 also incorporates a fixing unit 210 as in the image forming apparatus shown in FIG. 7, but the fixing unit 210 incorporated in the toner image forming apparatus shown in FIG. Is a roll type, and assumes primary fixing when viewed from the fixing processing of the entire image forming apparatus shown in FIG. The fixing unit 210 responsible for the primary fixing is composed of a pair of rolls 211 in contact with each other, and a nip region 212 is formed between the pair of rolls 211. The paper carrying the unfixed toner image is first fed into the nip area 212 and then conveyed to the fixing device 300 shown on the right side of FIG.

  The fixing device 300 shown on the right side of FIG. 8 incorporates the fixing device 20 of the present invention shown in FIG. 5. This fixing device 300 is seen from the fixing processing of the entire image forming apparatus shown in FIG. It is responsible for secondary fixing. The fixing device 300 includes an introduction port 310 into which a sheet discharged from the toner image forming apparatus 200 is introduced, and a switching gate 320 that switches a sheet conveyance path is provided inside the introduction port 310. . When the sheet discharged from the toner image forming apparatus 200 is not subjected to the secondary fixing process and is discharged as it is onto the first external discharge tray 350, the switching gate 320 causes the first conveying path to be moved upward. It is switched to the conveyance path 330 and discharged onto the first discharge tray 350 by the discharge roll 340.

  On the other hand, when the secondary fixing process is performed on the paper P discharged from the toner image forming apparatus 200, the conveyance path is switched to the second conveyance path 360 below by the switching gate 320, and the conveyance belt 370 It is conveyed to the fixing device 20 whose details are shown in FIG. The sheet conveyed to the fixing device 20 is subjected to the fixing process shown in FIG. 6 corresponding to the secondary fixing process here, and is discharged to the second discharge tray 390 by the discharge roll 380.

  As described above, the image forming apparatus of the present invention includes the fixing device (the fixing device of the present invention) including the fixing member of the present invention and the release agent supply device. Therefore, the unfixed toner image carried on the recording medium is fixed satisfactorily, and as a result, a good quality fixed toner image can be formed.

Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention.

(Example 1)
A fixing member 10a having the layer configuration shown in FIG. 1 was produced as follows.
As the base layer 12, an endless belt made of polyimide having a circumference of 527.8 mm × width of 420 mm × thickness of 75 μm and added with carbon black to adjust the volume resistivity to Rv = 10 ¹² Ω · cm is used. It was. On the surface of the base layer 12, SIFEL 610 (manufactured by Shin-Etsu Chemical Co., Ltd.): 100 parts by mass and barium sulfate (manufactured by Sakai Chemical Co., Ltd., BMH-60: mass average particle diameter 5 μm, 15 μm). The above large particles are 2% by mass or less): 20 parts by mass, fluorine-based solvent (mixed solvent of m-xylene hexafluoride, perfluoroalkane, perfluoro (2-butyltetrahydrofuran)): 30 parts by mass, A coating film is formed by applying the coating solution prepared by dip coating, followed by primary vulcanization at 120 ° C. for 10 minutes and secondary vulcanization at 200 ° C. for 2 hours to obtain a thick surface layer. A fixing belt (fixing member 10a) having a first rubber layer 14 having a thickness of 40 μm was obtained.

Here, the content of barium sulfate (inorganic particles) in the first rubber layer 14, that is, the layer made of fluorocarbonsiloxane rubber in which inorganic particles were dispersed was 16.7% by mass.
Further, the JIS A hardness of the first rubber layer 14 was 51 degrees as measured with a durometer type A according to JIS K 6253 “Method for testing hardness of added rubber and thermoplastic rubber”.
As an evaluation of the wettability with the release agent on the surface of the fixing belt obtained, the surface contact angle at 25 ° C. with respect to dimethyl silicone oil SH-200 (100 cs: manufactured by Toray Dow Corning Silicone) was measured using a contact angle meter ( FACE CA-X type (manufactured by Kyowa Interface Science Co., Ltd.) was used to measure contact angles at five locations, and the average value of the five obtained points was 22 degrees.
This fixing belt is a DocuCenterColor 500 (DCC500) manufactured by Fuji Xerox Co., Ltd. having substantially the same configuration as that of the image forming apparatus 1 shown in FIG. 7 (however, the fixing unit is modified to the fixing device 20 shown in FIG. 5). The image forming apparatus is called “DCC500 Kai”), and a full-color image is formed using four color developers for DCC500, and 100 kpv (print volume) in terms of A4 on the surface of the fixing belt. Repeated use was made. When the image quality after such long-term use was evaluated on the surface of the fixing belt, an image that was the same as the initial image could be obtained. The evaluation results are shown in Table 1.
In “DCC500 Kai”, dimethyl silicone oil SH-200 (100 cs: manufactured by Toray Dow Corning Silicone) was used as a release agent.

(Example 2)
A fixing belt was produced in the same manner as in Example 1 except that barium sulfate used in Example 1 was changed to Zeolite Toyobuilder (manufactured by Tosoh Corporation: average particle diameter of 1.5 μm).
When the JIS A hardness of the first rubber layer 14 in the obtained fixing belt was measured in the same manner as in Example 1, it was 48 degrees. Further, when the surface contact angle of the obtained fixing belt was measured in the same manner as in Example 1, it was 26 degrees.
Further, the obtained fixing belt was attached to “DCC500 Kai”, a full-color image was formed using four color developers, and the image quality after long-term use was evaluated in the same manner as in Example 1. I was able to obtain the same image. The evaluation results are shown in Table 1.

(Example 3)
Except that barium sulfate used in Example 1 was changed to fertile barium sulfate (manufactured by Sakai Chemical Co., Ltd .: BA: mass average particle diameter of 8 μm, large particles of 15 μm or more being 17% by mass), the same as Example 1 Thus, a fixing belt was produced.
When the JIS A hardness of the first rubber layer 14 in the obtained fixing belt was measured in the same manner as in Example 1, it was 55 degrees. Further, when the surface contact angle of the obtained fixing belt was measured in the same manner as in Example 1, it was 20 °.
Further, the obtained fixing belt is attached to “DCC500 Kai”, and a full-color image is formed by using four color developers for DocuPrint C1616 manufactured by Fuji Xerox Co., Ltd. As a result of the evaluation, an image that was the same as the initial image could be obtained. The evaluation results are shown in Table 1.

Example 4
The fixing belt was the same as in Example 1 except that SIFEL 611 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is a fluorocarbon siloxane rubber precursor composition, was used as a material for forming the first rubber layer 14 in the fixing belt of Example 1. Was made.
When the JIS A hardness of the first rubber layer 14 in the obtained fixing belt was measured in the same manner as in Example 1, it was 48 degrees. Further, when the surface contact angle of the obtained fixing belt was measured in the same manner as in Example 1, it was 22 degrees.
Further, the obtained fixing belt is attached to “DCC500 Kai”, and a full-color image is formed by using four color developers for DocuPrint C1616 manufactured by Fuji Xerox Co., Ltd. As a result of the evaluation, an image that was the same as the initial image could be obtained. The evaluation results are shown in Table 1.

(Example 5)
The fixing belt is the same as in Example 1 except that SIFEL650 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is a fluorocarbon siloxane rubber precursor composition, is used as a material for forming the first rubber layer 14 in the fixing belt of Example 1. Was made.
When the JIS A hardness of the first rubber layer 14 in the obtained fixing belt was measured in the same manner as in Example 1, it was 43 degrees. Further, when the surface contact angle of the obtained fixing belt was measured in the same manner as in Example 1, it was 21 °.
Further, the obtained fixing belt is attached to “DCC500 Kai”, and a full-color image is formed by using four color developers for DocuPrint C1616 manufactured by Fuji Xerox Co., Ltd. As a result of the evaluation, an image that was the same as the initial image could be obtained. The evaluation results are shown in Table 1.

(Example 6)
A fixing member 10d having the layer configuration shown in FIG. 4 was produced as follows.
As the base layer 12, an endless belt made of polyimide having a circumference of 527.8 mm × width of 420 mm × thickness of 75 μm and added with carbon black to adjust the volume resistivity to Rv = 10 ¹² Ω · cm is used. It was. The surface of the base layer 12 is impregnated with DY39-115 (manufactured by Toray Dow Corning Silicone Co., Ltd.), a primer for silicone rubber, and then air-dried for 30 minutes to form an adhesive layer 18. did.
Thereafter, on the surface of the adhesive layer 18, DY35-796AB (manufactured by Toray Dow Corning Silicone): 100 parts by mass and n-hexane: 30 parts by mass of a silicone rubber precursor composition. Was applied by dip coating to form a coating film, followed by primary vulcanization at 120 ° C. for 10 minutes to form a second rubber layer having a thickness of 40 μm.
Then, on the surface of the second rubber layer, this time, SIFEL 610 (manufactured by Shin-Etsu Chemical Co., Ltd.) which is a fluorocarbon siloxane rubber precursor composition: 100 parts by mass and barium sulfate (manufactured by Sakai Chemical Co., Ltd .: BMH-60: average) Particle size of 5 μm, large particles of 15 μm or more are 2% by mass or less): 20 parts by mass and fluorine-based solvent (mixed solvent of m-xylene hexafluoride, perfluoroalkane, perfluoro (2-butyltetrahydrofuran)): 20 parts by mass and a coating solution prepared by dip coating to form a coating film, followed by 120 ° C .: primary vulcanization for 10 minutes, 180 ° C .: secondary vulcanization for 4 hours, A first rubber layer having a thickness of 20 μm was formed, and a fixing belt (fixing member 10d) having a laminate composed of a first rubber layer and a second rubber layer as a surface layer was obtained.

Here, the content of barium sulfate (inorganic particles) in the first rubber layer 14, that is, the layer made of fluorocarbonsiloxane rubber in which inorganic particles were dispersed was 16.7% by mass.
When the JIS A hardness of the first rubber layer 14 in the obtained fixing belt was measured in the same manner as in Example 1, it was 50 degrees. Further, when the surface contact angle of the obtained fixing belt was measured in the same manner as in Example 1, it was 21 °.
Further, the obtained fixing belt was attached to “DCC500 Kai”, a full-color image was formed using four color developers, and the image quality after long-term use was evaluated in the same manner as in Example 1. I was able to obtain the same image. The evaluation results are shown in Table 1.

(Comparative Example 1)
As the base layer, an endless belt made of polyimide having a circumference of 527.8 mm × width of 420 mm × thickness of 75 μm and having a volume resistivity adjusted to Rv = 10 ¹² Ω · cm by adding carbon black was used. . On the surface of the base layer 12, 100 parts by mass of SIFEL610 (manufactured by Shin-Etsu Chemical Co., Ltd.), which is a fluorocarbon siloxane rubber precursor composition, and a fluorine-based solvent (m-xylene hexafluoride, perfluoroalkane, perfluoro (2- A mixed solvent of butyltetrahydrofuran)): 30 parts by mass, a coating solution is formed by dip coating, and then a coating film is formed. Then, 120 ° C .: primary vulcanization for 10 minutes, 180 ° C .: 4 hours Then, a fixing belt having a fluorocarbon siloxane rubber layer having a thickness of 40 μm as a surface layer was obtained.

When the surface contact angle of the obtained fixing belt was measured in the same manner as in Example 1, it was 45 °.
Further, the obtained fixing belt was attached to “DCC500 Kai”, a full color image was formed using four color developers, and the image quality after long-term use was evaluated in the same manner as in Example 1. In comparison with, an image in which the gloss of the entire surface was reduced by 20% by the evaluation of 20 ° gloss was obtained. The evaluation results are shown in Table 1.

(Comparative Example 2)
The fixing belt was the same as in Example 1 except that DY35-796AB (manufactured by Toray Dow Corning Silicone), which is a silicone rubber precursor composition, was used instead of the fluorocarbon siloxane rubber precursor composition in Example 1. However, it was not possible to disperse barium sulfate satisfactorily and a fixing belt satisfying the surface property could not be obtained.
Further, the obtained fixing belt was attached to “DCC500 Kai”, a full color image was formed using four color developers, and the image quality after long-term use was evaluated in the same manner as in Example 1. When the images were compared, it was possible to visually confirm that the gloss was partially different, and the image was unusable. When the surface of the fixing belt at this time was observed, a portion where a substance including wax, developer, and paper powder was fixed was observed. The evaluation results are shown in Table 1.

(Comparative Example 3)
A fixing belt was prepared in the same manner as in Comparative Example 1 except that DY35-7002AB (manufactured by Toray Dow Corning Silicone) was used instead of the fluorocarbonsiloxane rubber precursor composition in Example 1. However, it was not possible to disperse barium sulfate satisfactorily and a fixing belt satisfying the surface property could not be obtained.
Further, the obtained fixing belt was attached to “DCC500 Kai”, a full color image was formed using four color developers, and the image quality after long-term use was evaluated in the same manner as in Example 1. When the images were compared, it was possible to visually confirm that the gloss was partially different, and the image was unusable. When the surface of the fixing belt at this time was observed, a portion where a substance including wax, developer, and paper powder was fixed was observed. The evaluation results are shown in Table 1.

(result)
As is apparent from Table 1, the fixing belts (fixing members of the present invention) in Examples 1 to 6 were able to obtain an image that was the same as the initial image when evaluated for image quality after long-term use. Was also good.
On the other hand, in Comparative Example 1, in the evaluation of the image quality after long-term use, an image in which the gloss on the entire surface was reduced by 20% in the evaluation of 20 ° gloss compared to the initial case was obtained. In Comparative Examples 2 and 3, in the evaluation of the image quality after long-term use, when uniform images were compared, it was possible to visually confirm that the gloss was partially different, and the images were unusable. This is because a substance containing wax, developer, and paper dust is fixed on the surface of the fixing belt on the surface of the fixing belt.

  As described above, the first rubber layer 14 is a layer made of fluorocarbon siloxane rubber in which inorganic particles are dispersed, and a fixing belt having a surface contact angle with dimethyl silicone oil at 25 ° C. of 40 ° C. or less is used. It can be seen that deterioration in image quality can be prevented even after repeated use of 100 kpv (print volume) in terms of A4. That is, it can be seen that the toner on the surface of the fixing belt is prevented from being contaminated, the deterioration of the image gloss is suppressed and the deterioration of the image quality is suppressed, and a high-quality fixed toner image can be obtained over a long period of use. .

FIG. 3 is a schematic cross-sectional view of a main part showing a layer structure in the first embodiment of the fixing member of the present invention. It is a principal part schematic sectional drawing which shows the layer structure in 2nd Embodiment of the member for fixing of this invention. It is a principal part schematic sectional drawing which shows the layer structure in 3rd Embodiment of the fixing member of this invention. It is a principal part schematic sectional drawing which shows the layer structure in 4th Embodiment of the fixing member of this invention. 1 is a schematic configuration diagram illustrating an exemplary embodiment of a fixing device of the present invention. 6 is a flowchart showing each step of an image fixing method implemented in an exemplary embodiment of the fixing device of the present invention shown in FIG. 5. 1 is a schematic configuration diagram of a full-color image forming apparatus that is a first embodiment of an image forming apparatus of the present invention. It is a schematic block diagram which shows the 2nd aspect of the image forming apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 10a, 10b, 10c, 10d Fixing member 12 Base layer 14 1st rubber layer 16 2nd rubber layer 18 Adhesive layer 20 Fixing device 24 Fixing belt 100 Toner image forming part 200 Toner image forming apparatus (toner Image forming unit)
300 Fixing device

Claims (13)

The fixing member has a configuration including a base layer and a surface layer provided on the base layer, and is in contact with an unfixed toner image carried on a recording medium and applies heat and pressure to the unfixed toner image. And
For fixing, wherein the surface layer has a surface formed of a layer made of a fluorocarbon siloxane rubber in which inorganic particles are dispersed, and a contact angle of the surface with respect to dimethyl silicone oil at 25 ° C. is 40 degrees or less. Element.   The mass average particle diameter of the inorganic particles is 0.5 μm or more and 15 μm or less, and the inorganic particles are contained in a ratio of 1 to 30% by mass in the layer made of the fluorocarbon siloxane rubber. The fixing member according to 1.   The mass average particle diameter of the inorganic particles is 0.5 μm or more and 10 μm or less, and particles having a particle diameter of 15 μm or more are 25% by mass or less of the whole particles. Fixing member.   The fixing member according to claim 2, wherein the inorganic particles are contained in the layer made of the fluorocarbon siloxane rubber at a ratio of 5 to 25% by mass. The fixing member according to claim 1, wherein the inorganic particles are at least one selected from the group consisting of BaSO ₄ and zeolite.   The fixing according to any one of claims 1 to 5, wherein the fluorocarbon siloxane rubber is a fluorocarbon siloxane rubber having a perfluoroalkyl ether group and / or a perfluoroalkyl group in a main chain. Materials.   The surface layer is a laminate comprising a first rubber layer made of fluorocarbon siloxane rubber in which the inorganic particles are dispersed, and a second rubber layer made of silicone rubber provided thereunder. The fixing member according to any one of claims 1 to 6.   The fixing member according to claim 7, wherein the second rubber layer is thicker than the first rubber layer.   The fixing member according to claim 1, wherein the surface layer has a thickness of 300 μm or less.   10. The JIS A hardness according to JIS K 6253 of the layer made of fluorocarbon siloxane rubber in which the inorganic particles are dispersed is 5 degrees or more and 80 degrees or less, according to claim 1. The fixing member as described. At least the fixing member according to any one of claims 1 to 10,
A release agent supply device for supplying a release agent to the surface of the fixing member;
A fixing device comprising: A fixing step of fixing an unfixed toner image on a recording medium using at least the fixing member according to any one of claims 1 to 10;
A peeling step of peeling the recording medium from the surface of the fixing member;
A release agent supplying step of supplying a release agent to the surface of the fixing member;
An image fixing method comprising: At least a toner image forming unit for carrying an unfixed toner image on a recording medium;
A fixing member according to any one of claims 1 to 10,
A release agent supply device for supplying a release agent to the surface of the fixing member;
An image forming apparatus comprising:

Images