JP5119724B2 - Sliding member for fixing device, fixing device and image forming apparatus - Google Patents

Description

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

In an image forming apparatus used for an electrophotographic copying machine, a printer, a facsimile, or the like, an unfixed toner image transferred onto a recording medium such as paper is heated and pressed to place the toner image on the recording medium. A fixing device for fixing is provided.
As such a fixing device, a fixing device adopting a belt nip method using a belt-like rotating body driven by a fixing roll (or pressure roll) as a predetermined driving member is an energy-saving fixing device with a short warm-up time. Known as.

As conventional techniques related to this method, for example, a rotatable heat-fixing roll whose surface is elastically deformed, an endless belt (belt-shaped rotating body) that can run while being in contact with the heat-fixing roll, and an inner side of the endless belt And a pressure pad arranged in a non-rotating state.
This is because the endless belt is pressed against the heat fixing roll so that a contact surface with the heat fixing roll is formed by the pressure pad, and the belt can be passed between the endless belt and the heat fixing roll. A nip is provided and the sheet outlet side of the surface of the heat fixing roll is elastically deformed locally (see, for example, Patent Document 1).

In the fixing device employing such a belt nip method, in order to guarantee an excellent fixed image and fixability with respect to the recording medium, slip between the fixing roll and the recording medium, and the recording medium and the belt It is indispensable to prevent slip between the rotating body.
That is, if the friction coefficient between the fixing roll and the recording medium is μa, the friction coefficient between the recording medium and the belt-shaped rotating body is μb, and the friction coefficient between the belt-shaped rotating body and the pressing member is μc, at least μa> It is necessary to satisfy the relationship of μc and μb> μc.
In order to reduce the friction coefficient μc in this way, a coating layer (low friction sheet) made of a glass fiber sheet (so-called fluororesin impregnated glass cloth sheet) that has been coated or baked with a fluororesin is conventionally coated on the pressing member. In addition, it has been proposed that various modified silicone oils be interposed as a lubricant between the coating layer and the belt tubular body (for example, see Patent Documents 2 and 3).

  The present applicant also provides a non-porous sheet comprising a heat-resistant resin such as a fluororesin on the surface of the fluororesin-impregnated glass fiber sheet as the coating layer (low friction sheet). Have been proposed (see, for example, Patent Document 4).

Japanese Patent No. 3298354 JP-A-10-213984 JP 2001-249558 A JP 2004-206105 A

  An object of the present invention is to provide a sliding member for a fixing device that has excellent heat stability and strength and is less likely to be charged even if it is used for a long time.

Thus, the fixing member sliding member to which the present invention is applied includes a non-conductive surface layer disposed on the friction surface side and a conductive layer having conductivity disposed below the surface layer. And
Here, the conductive layer preferably contains 0.5 to 30 parts by mass of a conductive filler with respect to 100 parts by mass of the heat-resistant resin, and includes a base material layer including a heat-resistant woven fabric and a back surface including the heat-resistant resin. More preferably, at least one of the base material layer and the back surface layer has conductivity.
The heat-resistant woven fabric impregnated with the thermoplastic resin is preferably sandwiched between the front surface layer and the back surface layer, and the heat-resistant woven fabric preferably contains at least a part of conductive fibers.
The surface layer is preferably non-porous, more preferably contains a non-conductive heat-resistant resin, and the heat-resistant resin is preferably a fluororesin.

A fixing device to which the present invention is applied includes a rotatable fixing member, a belt-like rotating body that can move while contacting the fixing member, and an inner side of the belt-like rotating body. A pressure member that forms a contact portion through which the recording material passes between the fixing member and the belt-like rotator, and a sliding member provided between the belt-like rotator and the pressure member, A sliding member is provided with the nonelectroconductive surface layer distribute | arranged to the friction surface side, and the electroconductive conductive layer distribute | arranged to the lower layer of a surface layer, It is characterized by the above-mentioned.
Here, the conductive layer is preferably grounded.

  On the other hand, an image forming apparatus to which the present invention is applied includes a toner image forming unit that forms a toner image, a transfer unit that transfers the toner image to a recording medium, and a fixing unit that fixes the toner image on the recording medium. The fixing means is a rotatable fixing member, a belt-like rotator that is movable while being in contact with the fixing member, and a fixing member that is disposed inside the belt-like rotator and presses the belt-like rotator against the fixing member. A pressure member that forms a contact portion through which the recording material passes with the belt-shaped rotating body, and a sliding member provided between the belt-shaped rotating body and the pressure member, the sliding member on the friction surface side A non-conductive surface layer is provided, and a conductive layer having conductivity is provided below the surface layer.

According to the first aspect of the present invention, it is possible to obtain a sliding member for a fixing device that is excellent in heat stability and strength and is less likely to be charged even when used for a long time as compared with a case where the layer configuration is not taken into consideration.
In addition, compared with a case where the structure of the surface layer is not taken into consideration, it is possible to obtain a sliding member for a fixing device that can prevent the lubricant from penetrating into a layer below the surface layer.
Furthermore, it is possible to obtain a sliding member for a fixing device which is superior in heat resistance qualities and strengths compared to the case where this configuration is not used.
According to the second aspect of the invention, it is possible to obtain a sliding member for a fixing device that is less easily charged than when the content of the conductive filler is not taken into consideration.
Furthermore, according to the third aspect of the present invention, it is possible to obtain a sliding member for a fixing device that is not rounded during production and does not cause inconvenience in subsequent dimension cuts, as compared with the case where the configuration of the conductive layer is not taken into consideration. Can do.
Furthermore, according to the invention described in claim 4, it is possible to obtain a sliding member for a fixing device that can be easily manufactured at the time of manufacture as compared with the case where this configuration is not used.
Furthermore, according to the fifth aspect of the present invention, it is possible to obtain a sliding member for a fixing device that can be easily and less easily charged as compared with the case where this configuration is not used.
Furthermore, according to the sixth aspect of the present invention, it is possible to obtain a sliding member for a fixing device which is superior in workability and friction characteristics compared to the case where this configuration is not used.
Further, according to the invention described in claim 7 , compared with the case where this configuration is not used, the fixing device in which the pressure distribution between the belt-like rotating body and the recording medium is uniform even when the belt is used for a long time. Is obtained.
Furthermore, according to the eighth aspect of the present invention, it is possible to obtain a fixing device that can be easily prevented from being charged as compared with the case where this configuration is not used.
Furthermore, according to the ninth aspect of the present invention, there is provided an image forming apparatus in which unevenness of an image formed on a recording medium does not occur even when the apparatus is used for a long time as compared with the case where this configuration is not used. can get.

  Hereinafter, the best mode (embodiment) for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist. Also, the drawings used are used to describe the present embodiment and do not represent the actual size.

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus to which the exemplary embodiment is applied.
The image forming apparatus 50 shown in FIG. 1 includes a photoconductor (image carrier) 52 that rotates in a predetermined direction (the direction of arrow F in FIG. 1).
A charging device 54, an exposure device 56, a developing device 58, a transfer device 60, and a cleaning member 62 are provided around the photoconductor 52 along the rotation direction of the photoconductor 52.
The charging device (charging unit) 54 charges the surface of the photoconductor 52 to a predetermined potential. The exposure device (latent image forming means) 56 exposes the surface of the photoreceptor 52 charged by the charging device 54 to form an electrostatic latent image corresponding to the image data.
The developing device (developing means) 58 stores a developer containing toner for developing the electrostatic latent image in advance, and develops the electrostatic latent image by supplying the stored developer to the surface of the photoconductor 52. Thus, a toner image is formed.
The transfer device (transfer means) 60 transfers the toner image formed on the photoreceptor 52 to the recording medium K by sandwiching and transporting the recording medium K with the photoreceptor 52.
Further, the image forming apparatus 50 is provided with a fixing device (fixing means) 10 to which the present embodiment described in detail later is applied. The recording medium K onto which the toner image has been transferred by the transfer device 60 is transported to the fixing device 10 by a transport mechanism (not shown) to the transfer device 60, and the transferred toner image is fixed by the fixing device 10.
The cleaning member 62 is provided so as to come into contact with the surface of the photoconductor 52 and removes surface deposits by a frictional force with the surface of the photoconductor 52.

Next, the fixing device 10 to which the exemplary embodiment is applied will be described.
FIG. 2 is a cross-sectional side view illustrating the configuration of the fixing device 10 to which the exemplary embodiment is applied.
2 includes a fixing roll 11 that is a driving member and rotates in the direction of arrow A, and a resin film tubular body that contacts the fixing roll 11 and rotates in the direction of arrow B following the fixing roll 11. 12 (corresponding to an example of a belt-like rotating body).
The fixing roll 11 is disposed inside the core 11a, a cylindrical core 11a, an elastic layer 11b formed on the outer peripheral surface of the core 11a, a release layer 11c formed on the surface of the elastic layer 11b, and the core 11a. And a heating source 11d.
Further, the fixing device 10 is in contact with the inner peripheral surface of the resin film tubular body 12 and slides with the resin film tubular body 12, and is used for a sheet-like fixing device to which the present embodiment described in detail later is applied. A sliding member 13 and a pressing member 14 that presses the resin film tubular body 12 against the sheet-like fixing device sliding member 13 are provided. The pressing member 14 is attached to the support 15.
The fixing device 10 is a device for fixing a toner image to a recording medium by holding and pressing a recording medium (not shown) holding an unfixed toner image at a nip portion 16. The fixing roll 11 and the resin film tubular body 12 constituting the fixing device 10 rotate in the directions of arrows A and B and are heated to a predetermined temperature by the heating source 11d. Further, a lubricant is present between the sheet-like fixing device sliding member 13 and the resin film tubular body 12. For this reason, the friction coefficient between the sheet-like fixing device sliding member 13 and the resin film tubular body 12 is kept low. The resin film tubular body 12 may be supported in an unstretched state, or may be supported in a stretched manner by being stretched over a plurality of rolls.

  Next, the fixing roll 11, the resin film tubular body 12, the pressing member 14, the lubricant (not shown), and the fixing device sliding member 13 constituting the fixing device 10 will be described in detail.

The fixing roll 11 as a fixing member is not particularly limited with respect to its shape, structure, size and the like, and can be appropriately selected from those known per se according to the purpose.
As described above, since the release layer 11c is formed on the surface of the elastic layer 11b in the fixing roll 11, the offset of the toner image can be suitably prevented, and the fixing device 10 can be stably installed. This is advantageous in that it can be operated.

  The material of the core 11a constituting the fixing roll 11 is not particularly limited as long as the material is excellent in mechanical strength and heat conductivity. For example, a metal alloy such as aluminum, SUS, iron, copper, ceramics, FRM etc. are mentioned.

The material of the elastic layer 11b can be appropriately selected from known materials for the elastic layer 11b. For example, silicone rubber, fluorine rubber and the like can be mentioned.
Among these materials, silicone rubber is preferable because it has low surface tension and excellent elasticity. Examples of the silicone rubber include RTV silicone rubber and HTV silicone rubber. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ), and fluorosilicone. Examples thereof include rubber (FVMQ).

  The thickness of the elastic layer 11b is usually 3 mm or less, preferably 0.3 mm to 1.5 mm. There is no restriction | limiting in particular as a method of forming the elastic layer 11b on the surface of the core 11a, For example, the coating method and shaping | molding method etc. which are known per se can be employ | adopted.

The material of the release layer 11c is not particularly limited as long as it exhibits an appropriate release property with respect to the toner image, and examples thereof include fluorine rubber, silicone rubber, and fluorine resin. Among these materials, a fluororesin is preferable.
Examples of the fluororesin include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA), and tetrafluoroethylene-perfluoroethyl vinyl ether copolymer (EFA). , Polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polyethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluorinated ethylene (PCTFE), fluoride Examples include fluororesins such as vinyl (PVF), and polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether are particularly preferred in terms of heat resistance and mechanical properties. Coalescence (PFA), tetrafluoroethylene - perfluoro methyl vinyl ether copolymer (MFA), and tetrafluoroethylene - perfluoro ethyl vinyl ether copolymer (EFA) is preferably used.

The thickness of the release layer 11c is usually 10 μm to 100 μm, preferably 20 μm to 40 μm. There is no restriction | limiting in particular as a method of forming the mold release layer 11c in the surface of the elastic layer 11b, For example, the coating method mentioned above etc. are mentioned. Moreover, the method of coat | covering the tube formed by extrusion molding etc. is mentioned.
The fixing member is not limited to the fixing roll 11 and may be appropriately selected such as a roll shape or a belt shape as long as the fixing member can be rotated.

The heating source 11d only needs to heat the nip portion 16, and is not limited to the type that internally heats the fixing roll 11.
That is, the resin film tubular body 12 and the sheet-like fixing device sliding member 13 are heated as well as the type in which the nip portion is heated via the fixing member as in the type in which the fixing device is heated from the outside. In this case, it is possible to appropriately select one that heats the nip portion 16 or one that heats the belt-like fixing member itself by electromagnetic induction heating or the like.

Further, the resin film tubular body 12 is not particularly limited in its shape, size, etc., and can be appropriately selected from those known per se according to the purpose.
The resin film tubular body 12 is generally a belt formed endlessly. The structure of the resin film tubular body 12 may be a single layer structure or a multilayer structure. Examples of the multilayer resin film tubular body 12 include those having at least a base layer and a release layer.

Examples of the material of the resin film tubular body 12 include thermosetting polyimide, thermoplastic polyimide, polyamide, and polyamideimide. Among these, thermosetting polyimide is preferable in terms of excellent heat resistance, wear resistance, chemical resistance, and the like.
Examples of the material of the release layer include PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE ( Fluorine resins such as polyethylene-tetrafluoroethylene), PVDF (polyvinylidene fluoride), PCTFE (polychlorotrifluoride ethylene), PVF (vinyl fluoride); polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), Silicone rubbers such as methylphenyl silicone rubber (PMQ) and fluorosilicone rubber (FVMQ); vinylidene fluoride rubber; tetrafluoroethylene-propylene rubber; fluorophosphazene rubber; tetrafluoroethylene - fluororubber such as perfluoro vinyl ether rubbers, and the like.

The pressing member 14 is an elastic member and is mounted on the support 15 to press the resin film tubular body 12 against the fixing roll 11 via the sheet-like fixing device sliding member 13.
The pressing member 14 may be appropriately selected as long as the pressing member 14 is fixedly disposed and presses the resin film tubular body 12 toward the fixing roll 11. From the viewpoint of preventing deterioration due to heat at the time of fixing. If it does, it is preferable to comprise with what has heat resistance. The pressing member 14 which is an elastic body is fixed to the support body 15 with a heat-resistant member such as a spring.

The material of the elastic body of the pressing member 14 can be appropriately selected from known materials according to the purpose. In particular, silicone rubber having a durometer hardness of A10 ° to A40 ° is preferably used in terms of hardness and heat stability.
In addition, there is no restriction | limiting in particular about the shape of the press member 14, a structure, a magnitude | size, etc., It can select suitably according to the objective. For example, the pressing member 14 may have a structure composed of a single member or a structure composed of a plurality of members having different functions.

The lubricant present between the sheet-like fixing device sliding member 13 and the resin film tubular body 12 is important in that it has excellent lubricity, but this index has kinematic viscosity, and the fixing device When using in No. 10, it is necessary to consider heat resistance, volatility and the like.
In this respect, silicone oil is preferable, and amino-modified silicone oil having superior wettability is more preferable. In addition, when superior performance is required due to heat resistance, it is also preferable to use methylphenyl silicone oil.
In addition, in order to improve heat resistance, it is also possible to add a trace amount antioxidant in silicone oil.

The lubricant is preferably an amino-modified silicone oil containing an antioxidant, but is preferably an amino-modified silicone oil, a dimethyl silicone oil, a mercapto-modified silicone oil, or an amino-modified silicone oil containing an aromatic amine antioxidant. A hindered amine oil, an amine-modified oil containing an organometallic (titanate) antioxidant, and the like can be used.
However, considering long-term use, it is particularly desirable to use an amine-modified silicone oil containing an organometallic (titanate) antioxidant having high heat resistance and little thermal degradation.

When silicone oil is used as the lubricant, the viscosity is preferably 50 centistokes to 3000 centistokes at room temperature.
Here, the lower limit value is determined based on the viewpoint of preventing unnecessary evaporation of the silicone oil, while the upper limit value prevents the silicone oil from becoming a factor in increasing the sliding resistance. It is determined based on a viewpoint.
Furthermore, when used at high temperatures, it is most desirable to use perfluoropolyether oil that has excellent heat stability.
The sheet-like fixing device sliding member 13 is of a type that does not hold a lubricant therein. Therefore, as the lubricant, a lubricant having a relatively high viscosity, for example, grease (for example, fluorine Fluorine grease based on oil (Sumitec F950 (manufactured by Sumiko Lubricant Co., Ltd.)) can be used, and the amount of lubricant to be used can be reduced.

  Specific examples of lubricants that can be applied include fluorine grease, dimethyl silicone oil, organometallic salt-added dimethylsilicone oil, hindered amine-added dimethylsilicone oil, organometallic salt and hindered amine-added dimethylsilicone oil, methylphenyl silicone oil, Examples thereof include an amino-modified silicone oil added with an organic metal salt, a hindered amine-added amino-modified silicone oil, a perfluoropolyether oil, a modified perfluoropolyether oil, and a perfluoropolyether oil containing a modified perfluoropolyether oil.

Next, the fixing device sliding member 13 will be described.
FIG. 3 is a side sectional view of the fixing device sliding member 13 to which the exemplary embodiment is applied.
The fixing device sliding member 13 shown in FIG. 3 has a sheet shape, and its side cross section is from the friction surface side that contacts the resin film tubular body 12 (see FIG. 2) via a lubricant. A surface layer 21 containing a non-conductive heat-resistant resin, and a base material layer 22 and a back surface layer 23 that are conductive layers are provided thereunder, and one or both of the base material layer 22 and the back surface layer 23 have conductivity. ing.
Here, “non-conductive” refers to a volume resistance of 1 × 10 ¹³ Ω · cm or more under an applied condition of 100 V and 10 s according to a volume resistance measurement method shown in JIS-K6911.
Moreover, electroconductivity means volume resistance 1x10 < ⁹ > ohm * cm or less by the volume resistance measuring method shown to JIS-K6911 on the application conditions of 100V and 10s. If the volume resistance is excessively large, there is a possibility that the effect of removing charges due to frictional charging in the surface layer 21 is lost. The volume resistance is preferably 1 × 10 ⁶ Ω · cm or less, more preferably 1 × 10 ⁵ Ω · cm or less.
Further, the conductive layer is preferably grounded by another conductive member (not shown).

The distance between the surface of the surface layer 21 and the conductive layer is 1 μm to 2000 μm, preferably 5 μm to 1000 μm, more preferably 15 μm to 500 μm.
The sliding surface of the fixing device sliding member 13 is charged by the friction with the resin film tubular body 12 and charges are generated. However, if the distance between the surface of the surface layer 21 and the conductive layer is sufficiently close, the fixing device is used. Increase in the surface potential of the sliding member 13 and the belt-like rotating body can be suppressed.
However, if the surface layer 21 is too thin and is too close to the above distance, there is a risk of causing wear due to sliding wear.
On the other hand, if the distance is too far from the above distance, the surface potential may increase and the effect of the conductive layer may be reduced, and the flexibility of the sliding member 13 for the fixing device may be lost. As a result, the pressing pressure state of the pressing member 14 changes and the recording material is not peeled off.

Further, it is more preferable that the surface layer 21 is composed of a non-porous sheet made of a heat-resistant resin because the penetration of the lubricant into the lower layer can be prevented.
Here, the term “non-porous” means a sheet having no pores that are impregnated with a lubricant, and an oil impregnation amount can be used as an index thereof.
The amount of oil impregnation is the difference between the dry weight and the weight after applying oil on the sheet and rotating the roll around which the paper is wound with a force of 5 kg / cm ² for 1 minute. This is a calculated value.
In the present embodiment, the oil impregnation ^{amount, 0.01mg / mm 3 ~0.2mg / mm} 3, preferably suitably used those ^{0.01mg / mm 3 ~0.15mg / mm 3} .

The heat resistant resin is not particularly limited as long as it has sufficient heat resistance with respect to the fixing temperature (150 ° C. to 200 ° C.). Specifically, for example, thermosetting polyimide, thermoplastic polyimide, polyamide, polyamideimide, silicone resin, fluorine resin, and the like can be given. Among these, a fluororesin is preferable from the viewpoints of workability, friction characteristics, and high chemical affinity with a lubricant.
As the fluororesin, PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), or modified products thereof (for example, polytetrafluoroethylene and perfluoroethylene) are used from the viewpoint of workability and friction characteristics. And the like modified with fluoropolyvinyl ether).

In addition, the fluororesin may be made of one type of material or may be a combination of two or more types of materials.
Moreover, modified polytetrafluoroethylene resin (PTFE) obtained by irradiating ionizing radiation (for example, electron beam, γ-ray, neutron beam, X-ray, high energy ion, etc.) is used as the fluororesin. Is also preferable. This modified polytetrafluoroethylene resin can improve wear resistance and durability, and can improve long-term stability.
Furthermore, the modified polytetrafluoroethylene resin is replaced with the aforementioned PTFE (polytetrafluoroethylene resin), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), or a modified product thereof (for example, polytetrafluoroethylene and It may be a mixture of perfluoropolyvinyl ether and the like.

Such a fluororesin non-porous sheet can be produced, for example, as follows.
First, PTFE molding powder (trade name: Teflon (registered trademark) 7-J (Mitsui DuPont Fluoro Chemical Co., Ltd.)) is filled into a predetermined mold, compression molded, and then heated and fired at a temperature equal to or higher than the melting point. Get the body.
Thereafter, the sheet is skived to a predetermined thickness with a metal blade to obtain a sheet. Moreover, when filling with a filler, after mixing and dispersing with powder, a similar process is obtained to obtain a sheet.

  As the base material layer 22 provided under the surface layer 21 described above, it is more preferable from the viewpoint of retaining the lubricant to use a base material having an uneven surface (hereinafter simply referred to as “base material”).

An example of such a substrate is a porous fiber sheet.
The porous fiber sheet may not be a porous fiber, but may be composed of a resin fiber woven fabric made porous by weaving the fibers. Such a woven fabric has a uniform surface irregularity interval, or it is easy to control the surface irregularity by arbitrarily setting the thickness of warp and weft fibers. It can be used suitably.
The material of the porous fiber sheet may be appropriately selected from polyethylene resin, fluororesin, etc., but considering heat resistance, durability, etc., porous PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene) It is preferable to use an ethylene-perfluoroalkyl vinyl ether copolymer) or FEP (tetrafluoroethylene-hexafluoropropylene copolymer).
Further, glass fibers and aramid fibers are also preferable from the viewpoint that strength can be added, and glass fibers are particularly preferable. Further, the base material layer 22 can be provided with conductivity by partially weaving conductive fibers such as SUS fibers and carbon fibers in the woven fabric.

As a method for producing a multilayer structure in which a non-porous sheet as the surface layer 21 is provided on a substrate, first, a thermoplastic resin is infiltrated into the substrate.
Next, a method in which the base material and the non-porous sheet are pressure-bonded by heating and pressurizing and laminating them as an adhesive is most preferable from the viewpoints of ensuring unevenness and adhesion stability.
In this method, a thermoplastic resin that can secure sufficient heat resistance against heat applied during fixing is used as an adhesive, and in the manufacturing process, heating and pressure bonding are performed at a temperature at which thermoplasticity is exhibited. Heat resistance when used as the moving member 13 can be ensured.

As a method of infiltrating the thermoplastic resin into the base material, a method of impregnating and drying the base material having unevenness in advance, a film-like thermoplastic resin sheet is sandwiched between the base material and the non-porous sheet, and pressure bonding is performed under overheating. For example, a method of bonding while allowing the thermoplastic resin to permeate may be used.
Examples of the thermoplastic resin include a low molecular weight fluororesin (for example, the aforementioned PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), EFA (tetrafluoroethylene-perfluoroethylene). Fluoroethyl vinyl ether copolymer), MFA (tetrafluoroethylene-perfluoromethyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer) and the like.
Needless to say, the thermoplastic resin used has a melting point lower than that of the film-like non-porous material.

On the other hand, when a non-porous fluororesin sheet is provided on the surface of the base material layer 22 as the surface layer 21, due to the difference in thermal expansion between heating and room temperature, the sheet is rounded during manufacturing, and subsequent dimension cuts, etc. May be inconvenient.
Therefore, it is preferable that the back surface layer 23 made of a non-porous fluororesin sheet is bonded so that the base material layer 22 is sandwiched between the front surface layer 21.
In this case, the fixing device sliding member 13 has a three-layer structure, but it can also be made conductive by blending a fluororesin sheet layer, which is the back surface layer 23 opposite to the sliding surface, with a conductive filler or the like. . Thereby, since a conductive layer exists in the whole back surface, since grounding becomes easier, it is further more preferable.
Moreover, it is preferable to contain a conductive filler 0.5 mass part-30 mass parts with respect to 100 mass parts of fluororesins which are heat resistant resins.
The type of conductive filler is not particularly limited. For example, metal fine particles such as copper, copper alloy, silver, nickel, and low melting point alloy (solder, etc.); zinc oxide, tin oxide, indium oxide, etc. Metal oxide fine particles; conductive carbon black such as ketjen black; conductive polymer particles such as polypyrrole and polyaniline; polymer fine particles coated with metal; conductive fibers such as metal fibers and carbon fibers can be used.
In addition, if the distance between the surface of the surface layer 21 and the conductive back surface layer 23 satisfies the above-mentioned distance, it is not always necessary to impart conductivity to the base material layer 22.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these Examples.

[Example 1]
An evaluation device having the same configuration as that of the fixing device 10 shown in FIG. 2 (color multifunction device DocuCenter C75550I manufactured by Fuji Xerox Co., Ltd.) and a full color pattern image output on J paper (manufactured by Fuji Xerox Office Supply Co., Ltd.) It used for the test. A specific configuration of the fixing device 10 is as follows.

The fixing roll 11 has an outer surface of a cylindrical aluminum core 11a having an outer diameter of 33.8 mm, a thickness of 3.0 mm, and a length of 415 mm, and a silicone HTV rubber (rubber hardness of 33 degrees: JIS-A) as an elastic layer 11b. ) Was coated to a thickness of 600 μm, and the surface of the elastic layer 11b was coated with PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) as a release layer 11c to a thickness of 30 μm. Inside the core 11a, a 1300 W halogen lamp was disposed as a heating source 11d.
The surface temperature of the fixing roll 11 was controlled to 185 ° C. by a temperature sensor of a temperature sensitive element arranged in contact with the surface of the fixing roll 11 and a temperature controller.

  The resin film tubular body 12 is composed of a thermosetting polyimide having a peripheral length of 94 mm, a wall thickness of 80 μm, and a length of 352 mm, and PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) is 30 μm on the outer peripheral surface of the base material. The release layer 11c was formed by coating to a thickness of.

  The pressing member 14, which is an elastic body, was disposed on the support 15, and a sheet-like fixing device sliding member 13 was attached to the pressing member 14 on the contact surface side with the resin film tubular body 12.

The support 15 is provided with a belt travel guide so that the resin film tubular body 12 rotates smoothly. The pressing member 14 is a silicone rubber having a width of 10 mm, a wall thickness of 5 mm, and a length of 340 mm. A rib in the belt rotation direction is provided on the surface of the belt traveling guide, and the contact area with the inner peripheral surface of the resin film tubular body 12 Was reduced. The pressing member 14 disposed on the support 15 pressed the fixing roll 11 with a load of 38 kg by a compression coil spring through the thin film-shaped resin film tubular body 12.
The winding angle of the resin film tubular body 12 around the fixing roll 11 was set to about 30 °.

  At this time, the width of the nip portion 16 was about 7 mm. In such a state, the driving force from the motor is transmitted to the fixing roll 11, and the fixing roll 11 and the resin film tubular body 12 are rotated at a speed of 320 mm / s.

On the surface of the pressing member 14, the following was used as the sheet-like fixing device sliding member 13 to which the exemplary embodiment is applied.
First, modified PTFE (Daikin Kogyo Co., Ltd .: New Polyflon M112: melting point 310 ° C.) is filled into a predetermined mold, compression molded, and then heated and fired at a temperature equal to or higher than the melting point to obtain a molded body. A thin film sheet (non-conductive non-porous sheet) having a thickness of 25.0 μm was obtained by katsura peeling with a metal blade. The oil impregnation amount of this non-porous sheet was 0.070 mg / mm ³ .

Next, a fluororesin-impregnated glass cloth sheet (manufactured by Chuko Kasei Kogyo Co., Ltd .: FGF300-4) obtained by impregnating glass cloth with PTFE was prepared as a base material.
Further, 100 parts by mass of polytetrafluoroethylene resin (PTFE resin manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) molding powder) and Ketjen Black EC (manufactured by Lion Corporation, average primary particle size 0.04 μm) 5 parts by mass was blended and mixed and dispersed in a state where the fluororesin was melted to produce pellets, and a substrate was produced using a compression molding machine. Then, a thin film sheet (non-porous conductive fluororesin sheet) having a thickness of 25.0 μm and a volume resistance value of 4 × 10 ³ Ω · cm was obtained by katsura peeling using a metal blade.

Next, the glass cloth sheet was superposed so as to be sandwiched between the non-conductive non-porous sheet and the non-porous conductive fluororesin sheet, and subjected to thermocompression bonding under conditions of 330 ° C.-60 kg / cm ² to form a sheet-like sheet having a thickness of 140 μm. A sliding member 13 for the fixing device was obtained.

This sheet-like fixing device sliding member 13 is cut into a width of 80 mm and a length of 346 mm, and the non-conductive porous fluororesin layer side is disposed on the pressing member as a surface that slides on the resin film. The layer was arranged and fixed so that a part of the layer was in contact with the ground contact portion in the belt guide traveling guide portion.
An amino-modified silicone oil (KF8009A; 400 centistokes manufactured by Shin-Etsu Chemical Co., Ltd.) is used as a lubricant between the sliding surface of the sheet-like fixing device sliding member 13 and the inner surface of the resin film tubular body 12. Intervened.

  With the above configuration and conditions, the fixing device 10 was operated, and the driving torque and the image quality of the print when printing was performed initially and after lapse of time (after printing 200,000 sheets) were confirmed. As a result, there was no change in the driving torque between the initial stage and time, and the image quality was very good.

  In addition, P paper (manufactured by Fuji Xerox Office Supply Co., Ltd.), which has a large toner charge amount and is susceptible to static electricity generation at a humidity of 15% RH and a low temperature and low humidity at a temperature of 10 ° C. Was used as a recording paper, and an image quality evaluation was performed by forming a 20% halftone image.

  As a result, an electrostatic offset phenomenon caused by static electricity (an image transfer phenomenon on the recording paper) and a lateral color line trace on the recording paper due to a peeling discharge generated when the front paper is peeled off the fixing roll 11 are generated. I did not.

[Example 2]
Evaluation was performed under the same condition configuration as in Example 1 except that the following members were used as the sheet-like fixing device sliding member 13.

  First, glass cloth (trade name: Glass cloth KS1231 (manufactured by Kanebo Corporation, fiber diameter warp: 22.5 g / 1000 m, weft: 22.5 g / 1000 m, density longitudinal direction: 41 / inch, lateral: 41 / Inch, plain weave) is impregnated with PTFE dispersion containing 6 parts by mass of Ketjen Black EC (manufactured by Lion Co., Ltd., average primary particle size 0.04 μm) as a base material. Prepared as.

Further, two non-conductive non-porous sheets used in Example 1 were prepared, and the above-described glass cloth base material was stacked so as to be sandwiched between the non-conductive non-porous sheets, and the conditions were 330 ° C.-60 kg / cm ² . Thermocompression bonding was performed to obtain a sheet-like fixing device sliding member 13 having a thickness of 140 μm.

  With the above configuration and conditions, the fixing device 10 was operated, and the driving torque and the image quality of the print when printing was performed initially and after lapse of time (after printing 200,000 sheets) were confirmed. As a result, there was no change in the driving torque between the initial stage and time, and the image quality was very good.

  In addition, P paper (manufactured by Fuji Xerox Office Supply Co., Ltd.), which has a large toner charge amount and is susceptible to static electricity generation at a humidity of 15% RH and a low temperature and low humidity at a temperature of 10 ° C. Was used as a recording paper, and an image quality evaluation was performed by forming a 20% halftone image.

  As a result, an electrostatic offset phenomenon caused by static electricity (an image transfer phenomenon on the recording paper) and a lateral color line trace on the recording paper due to a peeling discharge generated when the front paper is peeled off the fixing roll 11 are generated. I did not.

Example 3
Evaluation was performed under the same condition configuration as in Example 2 except that the following members were used as the base material of the sheet-like fixing device sliding member 13.

Fluorine resin impregnated metal produced by impregnating PTFE dispersion with plain weave cloth (Naslon (registered trademark) cloth A type (manufactured by Nippon Seisen Co., Ltd.)) made of SUS fiber as the base material of the sliding member 13 for the fixing device A cross sheet was used.
Then, they were overlapped so as to be sandwiched between two non-conductive non-porous sheets and subjected to thermocompression bonding to produce a sheet-like fixing device sliding member 13 having a thickness of 450 μm.

  With the above configuration and conditions, the fixing device 10 was operated, and the driving torque and the image quality of the print when printing was performed initially and after lapse of time (after printing 200,000 sheets) were confirmed. As a result, there was no change in the driving torque between the initial stage and time, and the image quality was very good.

  In addition, P paper (manufactured by Fuji Xerox Office Supply Co., Ltd.), which has a large toner charge amount and is susceptible to static electricity generation at a humidity of 15% RH and a low temperature and low humidity at a temperature of 10 ° C. Was used as a recording paper, and an image quality evaluation was performed by forming a 20% halftone image. As a result, an electrostatic offset phenomenon caused by static electricity (an image transfer phenomenon on the recording paper) and a lateral color line trace on the recording paper due to a peeling discharge generated when the front paper is peeled off the fixing roll 11 are generated. I did not.

[Comparative Example 1]
Evaluation was performed under the same condition configuration as in Example 1 except that the following members were used as the sheet-like fixing device sliding member 13.

A modified PTFE (manufactured by Daikin Industries, Ltd .: New Polyflon M112: melting point 310 ° C.) is filled into a predetermined mold, compression molded, and then heated and fired at a temperature equal to or higher than the melting point to obtain a molded body, and then a metal blade A 25.0 μm-thick thin film sheet (non-conductive non-porous sheet) was obtained by the Katsura peeling process. The oil impregnation amount of this non-porous sheet was 0.070 mg / mm ³ .

Next, a fluororesin-impregnated glass cloth sheet (manufactured by Chuko Kasei Kogyo Co., Ltd .: FGF300-4) obtained by impregnating glass cloth with PTFE was prepared as a base material.
The glass cloth substrate was superposed so as to be sandwiched between non-conductive and non-porous sheets, and thermocompression bonded under conditions of 330 ° C.-60 kg / cm ² to obtain a sheet-like fixing member sliding member 13 having a thickness of 140 μm. .

  With the above configuration and conditions, the fixing device 10 was operated, and the driving torque and the image quality of the print when printing was performed initially and after lapse of time (after printing 200,000 sheets) were confirmed. As a result, there was no change in the driving torque between the initial stage and time, and the image quality was very good.

  On the other hand, P paper (manufactured by Fuji Xerox Office Supply Co., Ltd.), which has a large toner charge amount and is susceptible to static electricity generation at a humidity of 15% RH and a low temperature and low humidity at a temperature of 10 ° C. Was used as a recording paper, and an image quality evaluation was performed by forming a 20% halftone image.

  As a result, an electrostatic offset phenomenon (image transfer phenomenon on the recording paper) occurs due to static electricity, and a horizontal color line trace on the recording paper is caused by the peeling discharge that occurs when the front paper is peeled off the fixing roll 11. Also occurred.

[Comparative Example 2]
As the sheet-like fixing device sliding member 13, the sheet-like fixing device sliding member 13 used in Example 2 was used as a surface on which the conductive non-porous fluororesin layer side slides with the resin film. Except for the above, evaluation was performed under the same condition configuration as in Example 1.

  With the above configuration and conditions, the fixing device 10 is operated, the toner charge amount is large, and the static electricity is easily generated. The humidity is 15% RH, and the temperature is low and low humidity at 10 ° C. Using the P paper (produced by Fuji Xerox Office Supply Co., Ltd.) as the recording paper, the image quality was evaluated by forming a 20% halftone image.

As a result, an electrostatic offset phenomenon caused by static electricity (an image transfer phenomenon on the recording paper) and a lateral color line trace on the recording paper due to a peeling discharge generated when the front paper is peeled off the fixing roll 11 are generated. I did not. However, with regard to durability, there was no problem in the driving torque at the beginning, but the driving torque gradually increased, and when 60,000 sheets were printed, the driving torque increased, and the sliding resistance of the resin film tubular body 12 Increased, confirming the occurrence of image misalignment.
When the inside of the fixing device 10 is confirmed, the wear of the sliding surface of the sheet-like fixing device sliding member 13 is large, and the friction resistance is increased by exposing the glass cloth of the base material and mixing the wear powder into the lubricant. It was confirmed.

  Tables 1 and 2 below summarize the results of Examples 1 to 3 and Comparative Examples 1 and 2 described above.

As described above, the fixing device sliding member 13 described in detail in the present embodiment can solve the following problems of the conventional fixing device sliding member.
(1) When a fluororesin-impregnated glass cloth sheet is used as a sliding member for a fixing device for a long period of time, the outermost fluororesin layer is worn out, and the glass fiber sheet as a reinforcing substrate is exposed. As a result, the reliability of the resin film tubular body is impaired.
(2) As a countermeasure, a sliding member for a fixing device in which a non-porous sheet comprising a heat-resistant resin such as a fluorine resin is further provided on the surface of a fluororesin-impregnated glass cloth sheet is a fixing device. In some cases, the toner image formed on the recording medium is disturbed by electric charges generated by frictional charging generated between the sliding member for resin and the tubular resin film.
(3) In order to prevent this, the sliding member for a fixing device in which conductivity is imparted to the non-porous sheet is used for friction of the sliding surface of the low friction sheet by blending a conductive agent, particularly under high speed and high load conditions. Wear increases. As a result, the wear torque increases under long-term use conditions and the driving torque increases due to wear of the non-porous sheet. In addition, due to the blending of the conductive agent, the adhesive force with the base material is reduced, a gap is generated between the base material, the lubricant is accumulated, and the pressure distribution becomes non-uniform so that an axial image is formed on the image. Unevenness may occur.

1 is a schematic configuration diagram illustrating an image forming apparatus to which the exemplary embodiment is applied. 1 is a side cross-sectional view illustrating a configuration of a fixing device to which the exemplary embodiment is applied. It is a sectional side view of the sliding member for fixing devices to which this embodiment is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fixing device, 11 ... Fixing roll, 11a ... Core, 11b ... Elastic layer, 11c ... Release layer, 11d ... Heat source, 12 ... Resin film tubular body, 13 ... Sliding member for fixing device, 14 ... Pressing member , 15 ... support, 16 ... nip, 21 ... surface layer, 22 ... base material layer, 23 ... back layer, 50 ... image forming device, 52 ... photoconductor, 54 ... charging device, 56 ... exposure device, 58 ... Developing device 60 ... Transfer device 62 ... Cleaning member

Claims (9)

Disposed on the friction surface, and a non-porous surface layer composed of a heat-resistant resin is non-conductive,
A sliding member for a fixing device, comprising: a conductive conductive layer disposed under the surface layer and having irregularities on the surface .   The sliding member for a fixing device according to claim 1, wherein the conductive layer contains 0.5 to 30 parts by mass of a conductive filler with respect to 100 parts by mass of the heat resistant resin. The conductive layer includes a base material layer including a heat-resistant woven fabric,
A back layer containing a heat resistant resin,
The sliding member for a fixing device according to claim 1, wherein at least one of the base material layer and the back surface layer has conductivity.   The sliding member for a fixing device according to claim 3, wherein the heat-resistant woven fabric impregnated with a thermoplastic resin is sandwiched between the front surface layer and the back surface layer.   The sliding member for a fixing device according to claim 3, wherein the heat-resistant woven fabric includes conductive fibers at least partially. The sliding member for a fixing device according to claim 1 , wherein the heat resistant resin is a fluororesin. A rotatable fixing member;
A belt-like rotating body that is movable while contacting the fixing member;
A pressure member that is disposed inside the belt-like rotator and presses the belt-like rotator against the fixing member to form a contact portion through which a recording material passes between the fixing member and the belt-like rotator; ,
A sliding member provided between the belt-like rotating body and the pressure member,
The sliding member is disposed on the friction surface side, and is a non -porous surface layer made of a heat-resistant resin that is non-conductive,
A fixing device comprising: a conductive conductive layer disposed under the surface layer and having irregularities on a surface thereof . The fixing device according to claim 7 , wherein the conductive layer is grounded. Toner image forming means for forming a toner image;
Transfer means for transferring the toner image to a recording medium;
Fixing means for fixing the toner image to a recording medium,
The fixing means is
A rotatable fixing member;
A belt-like rotating body that is movable while contacting the fixing member;
A pressure member that is disposed inside the belt-shaped rotating body, presses the belt-shaped rotating body against the fixing member, and forms a contact portion through which the recording material passes between the fixing member and the belt-shaped rotating body;
A sliding member provided between the belt-like rotating body and the pressure member,
The sliding member is disposed on the friction surface side, and is a non -porous surface layer made of a heat-resistant resin that is non-conductive,
An image forming apparatus comprising: a conductive conductive layer disposed under the surface layer and having irregularities on the surface .

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