JP2005164673A5 - Endless belt for electrophotographic apparatus and manufacturing method thereof, belt cartridge, process cartridge, and image forming apparatus - Google Patents

Description

SUMMARY OF THE INVENTION In view of the above-described problems, inexpensive to manufacture, long-term without any crack or cracks also be used, durable, small endless electrophotographic apparatus of dimensional change belt after molding and The manufacturing method is provided.

In accordance with the present invention, in the A acrylic resin, and rubber particles, and the conductive filler is a electrophotographic endless belt device having a layer comprising a resin composition dispersed, conductive filler, said acrylic resin An endless belt for electrophotography, characterized in that it is localized on the side, is provided.
Further, according to the present invention, an endless belt for an electrophotographic apparatus comprising a step of melt-molding a resin composition obtained by adding rubber particles and a conductive filler to an acrylic resin to form a cylindrical film A manufacturing method is provided .

As described above, according to the present invention, an endless belt for an electrophotographic apparatus that can be manufactured at low cost, has excellent creep resistance, flex resistance, dimensional stability, and can be used over a long period of time, and a method for manufacturing the same , It has become possible to provide a belt cartridge, a process cartridge, and an image forming apparatus provided with the endless belt for an electrophotographic apparatus.

In the present invention, in addition to the acrylic resin, a rubber component is added to improve the bending resistance. Conventionally, it has been generally performed to add a rubber component to a thermoplastic resin for the purpose of improving impact resistance. For example, HIPS (high impact polystyrene) and ABS (acrylonitrile-butadiene-styrene copolymer) are used. Etc. can be illustrated. However, the impact resistance and the bending resistance as an endless belt are different from each other. According to the study by the present inventors, even if an endless belt is made using a material having excellent impact resistance, the bending resistance is not necessarily limited. The result that it was not necessarily excellent in the property was obtained.

In the present invention, rubber particles are added to improve the bending resistance, but the particle size of the rubber particles is preferably 0.05 μm to 10 μm in consideration of dispersibility in an acrylic resin as a binder. If it is less than 0.05 μm, the particle size is too small and the rubber particles tend to aggregate, and the dispersibility deteriorates. If it exceeds 10 μm, the particle size is too large and the rubber part and the resin part are separated too much, leading to a decrease in mechanical properties. The particle diameter of the rubber particles of the present invention refers to the primary particle diameter, and does not refer to the diameter of the aggregated particles in which the primary particles are aggregated.

Usually, an acrylic resin to which rubber particles are added has a structure in which the resin is a matrix and the rubber is a domain. The compounding ratio of the preferred resin and rubber component is in the range of 30:70 to 95: 5. If the resin component is more than 95%, the effect on the bending resistance due to the addition of the rubber component is insufficient. Conversely, if the rubber component is more than 70%, the domain rubber The resin that is a matrix that fills the space between particles is not sufficient, and not only the moldability is poor, but also the mechanical properties are close to rubber, which is not preferable because it stretches or creeps when used as a belt.

In the present invention, a rubber component is added to improve the bending resistance, but the method for adding the rubber component is not particularly limited. You may add at the time of polymer polymerization which is an acrylic resin, and you may mix with a rubber component after becoming a polymer.

Usually, an acrylic resin is an insulating material itself and often does not function as an endless belt of an electrophotographic apparatus, and a conductive agent or an antistatic agent is added to adjust electric resistance. For example, examples of the conductive filler include carbon black and various conductive metal oxides, and examples of the non-filler resistance adjuster include low molecular weight ionic conductive agents such as various metal salts and glycols, ether bonds, and the like. Examples thereof include an antistatic resin containing a hydroxyl group in the molecule, an organic polymer compound exhibiting electronic conductivity, and the like. Accordingly, the additive to be mixed for adjusting the electric resistance value of the electrophotographic endless belt of the present invention is not particularly limited. Among these, carbon black is preferable because it is relatively inexpensive and can be adjusted in a small amount.

Usually, a conductive agent such as carbon black is used, and there is an inflection point where the electrical resistance value suddenly decreases as the amount added is increased, stabilizing the medium resistance region required for the electrophotographic process. it is difficult to produce Te, but is localized in the acrylic resin side of the carbon black by adding a rubber component in the acrylic resin as in the present invention, the resistance control such as dilute a rubber component it By doing so, there is also a merit that a resin composition in the middle resistance region can be obtained very stably.

Based on the desired formulation, materials such as acrylic resin, conductive agent, and additive may be premixed and then kneaded and dispersed with a twin screw extruder or the like as a raw material for molding, or each material may be put directly into the molding machine. Molding may be performed.

Claims (15)

In an acrylic resin, and rubber particles, and the conductive filler is a electrophotographic endless belt device having a layer comprising a resin composition dispersed, conductive fillers, localized in the acrylic resin side An endless belt for an electrophotographic apparatus . The endless belt for an electrophotographic apparatus according to claim 1, wherein the rubber particles have a particle diameter of 0.05 μm to 10 μm. The endless belt for an electrophotographic apparatus according to claim 1 or 2, wherein a mixing ratio of the acrylic resin and the rubber particles is 30:70 to 95: 5 by mass ratio. The endless belt for an electrophotographic apparatus according to claim 1, wherein the rubber particles have a multilayer structure. The endless belt for an electrophotographic apparatus according to claim 1, wherein the rubber particles are mainly composed of acrylic rubber. The endless belt for an electrophotographic apparatus according to claim 1, wherein the conductive filler is an electroconductive filler. The endless belt for an electrophotographic apparatus according to claim 6 , wherein the electroconductive filler is carbon black. It said resin composition further polyetherester, polyetheramide, or an electrophotographic apparatus for endless belt according to any one of claims 1 to 7 containing polyetheresteramide. The endless belt for an electrophotographic apparatus according to any one of claims 1 to 8 , wherein the endless belt is a transfer conveyance belt or an intermediate transfer belt. Said resin composition, rubber particles and electrophotographic apparatus for endless belt according to any one of claims 1 to 9 is obtained and a conductive filler each addition of the acrylic resin. A process for producing an endless belt for an electrophotographic apparatus, comprising a step of melt-molding a resin composition obtained by adding rubber particles and a conductive filler to an acrylic resin to form a cylindrical film. The method for producing an endless belt for an electrophotographic apparatus according to claim 11, wherein the step includes a step of performing blow molding of the resin composition or a step of performing blow molding. Belt cartridge, characterized by comprising one of the electrophotographic endless belt according to claim 1-10. The process cartridge characterized by comprising any one of the endless belt for an electrophotographic apparatus according to claim 1-10. An image forming apparatus comprising the endless belt for an electrophotographic apparatus according to claim 1 .