Patent Application
20080070041
The above embodiments will become apparent as the following description proceeds upon reference to the drawings, which include the following figures:
Referring to
After the toner particles have been deposited on the photoconductive surface, in image configuration, they are transferred to a copy sheet 16 by transfer means 15, which can be pressure transfer or electrostatic transfer. Alternatively, the developed image can be transferred to an intermediate transfer member and subsequently transferred to a copy sheet.
After the transfer of the developed image is completed, copy sheet 16 advances to fusing station 19, depicted in
In
Backup or pressure roll 6 cooperates with fuser roll 5 to form a nip or contact arc 9 through which a copy paper or other substrate 16 passes such that toner images 21 thereon contact fluoroelastomer surface 2 of fuser roll 5. As shown in
In the embodiment shown in
The fusing component can be comprised of at least three different configurations. In one embodiment, the fusing component is of a two-layer configuration as shown in
In embodiments, there may be present an outer release layer 27 positioned on the outer layer 2 as shown in
Examples of suitable substrate materials include, in the case of roller substrate, metals such as aluminum, stainless steel, steel, nickel and the like. In the case of film-type substrates (in the event the substrate is a fuser belt, film, drelt (a cross between a drum and a belt) or the like) suitable substrates include high temperature plastics that are suitable for allowing a high operating temperature (i.e., greater than about 80° C., or greater than 200° C.), and capable of exhibiting high mechanical strength.
The outer layer comprises a blended fluoroelastomer alloy. The blend comprises a filled-fluoroelastomer and an unfilled-fluoroelastomer. The first filled-fluoroelastomer and the second unfilled-fluoroelastomer may be the same or different.
Examples of suitable fluoroelastomers include copolymers and terpolymers of vinylidenefluoride, hexafluoropropylene and tetrafluoroethylene, which are known commercially under various designations as VITON A®, VITON E®, VITON E60C®, VITON E45®, VITON E430®, VITON 910®, VITON GH®, VITON B50®, and VITON GF®. The VITON® designation is a Trademark of E.I. DuPont de Nemours, Inc. Other commercially available materials include FLUOREL 2170®, FLUOREL 2174®, FLUOREL 2176®, FLUOREL 2177® and FLUOREL LVS 76® FLUOREL® being a Trademark of 3M Company. Additional commercially available materials include AFLAS™ a poly(propylene-tetrafluoroethylene) and FLUOREL II® (LII900) a poly(propylene-tetrafluoroethylene vinylidenefluoride) both also available from 3M Company, as well as the Tecnoflons identified as FOR-60KIR®, FOR-LHF®, NM® FOR-THF®, FOR-TFS®, TH®, TN505® available from Montedison Specialty Chemical Company.
Two specific known fluoroelastomers are (1) a class of copolymers of one or more of, or any combination of vinylidenefluoride, tetrafluoroethylene and hexafluoropropylene known commercially as VITON A® and (2) a class of terpolymers of vinylidenefluoride, hexafluoropropylene, and tetrafluoroethylene known commercially as VITON B®. VITON A®, and VITON B®, and other VITON® designations are trademarks of E.I. DuPont de Nemours and Company.
In another embodiment, the fluoroelastomer is a tetrapolymer having a relatively low quantity of vinylidenefluoride. An example is VITON GF®, available from E.I. DuPont de Nemours, Inc. The VITON GF® has 35 weight percent of vinylidenefluoride, 34 weight percent of hexafluoropropylene and 29 weight percent of tetrafluoroethylene with 2 weight percent cure site monomer. The cure site monomer can be those available from DuPont such as 4-bromoperfluorobutene-1, 1,1-dihydro-4-bromoperfluorobutene-1,3-bromoperfluoropropene-1,1,1-dihydro-3-bromoperfluoropropene-1, or any other suitable, known, commercially available cure site monomer.
In embodiments, the filled fluoroelastomer can include those commercially available under the trade name P95930M from Solvay Solexis, which is a 30% by weight PTFE-filled fluoroelastomer. The fluoroelastomer is a tetrapolymer of vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene and a cure site monomer. The PTFE particles are approximately 40 nm in size and are dispersed in the fluoroelastomer matrix during the manufacture of the fluoroelastomer.
In embodiments, a filled tetrapolymer of vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene and a cure site monomer, is blended with an unfilled tetrapolymer of vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, and a cure site monomer.
In embodiments, the filler in the filled-fluoroelastomer composition is a fluoropolymer such as polytetrafluoroethylene (PTFE), fluorinated ethylenepropylene copolymer (FEP), polyfluoroalkoxy polytetrafluoroethylene (PFA TEFLON®), ethylene chlorotrifluoro ethylene (ECTFE), ethylene tetrafluoroethylene (ETFE), polytetrafluoroethylene perfluoromethylvinylether copolymer (MFA), and the like, and mixtures thereof. The polymer filler has a particle size of from about 1 to about 40 nm.
The filler is present in the filled-fluoroelastomer composition in an amount of from about 10 to about 50 percent, or from about 20 to about 40 percent, or from about 30 to about 35 percent by weight of total solids.
In embodiments, the weight ratio of the filled-fluoroelastomer composition to the unfilled-fluoroelastomer composition in the outer layer is from about 0.01/99.9 to about 25/75, or from about 1/99 to about 10/90, or from about 2/98 to about 5/95.
The outer fluoroelastomer blend can be coated on the substrate using any suitable known manner. Typical techniques for coating such materials on the reinforcing member include liquid and dry powder spray coating, dip coating, wire wound rod coating, fluidized bed coating, powder coating, electrostatic spraying, sonic spraying, blade coating, and the like. In an embodiment, the fluoroelastomer blend is spray or flow coated to the substrate. Details of the flow coating procedure can be found in U.S. Pat. No. 5,945,223, the disclosure of which is hereby incorporated by reference in its entirety.
The fluoroelastomer blend is of a thickness of from about 5 to about 100 microns, or from about 20 to about 40 microns, or from about 15 to about 25 microns.
In an embodiment, the outer fluoroelastomer blended layer may be modified by any known technique such as sanding, polishing, grinding, blasting, coating, or the like. In embodiments, the outer fluoroelastomer blended layer has a surface roughness of from about 0.02 to about 1.5 micrometers, or from about 0.3 to about 0.8 micrometers. In the three layer embodiment, wherein an optional release layer is provided on the fluoroelastomer outer layer, the outer release layer surface can also be roughened in the same or similar manner as just described.
In an embodiment, the blended fluoroelastomer outer layer has a gardiner gloss of approximately from about 40 to about 100 ggu, or from about 60 to about 80 ggu, or about 70 to about 78 ggu.
The adhesion of the fluoroelastomer blended outer layer can be from about 1.5 to about 3 lb/in, or from about 2.1 to about 2.8 lb/in, or from about 2.2 to about 2.8 lb/in.
The outer layer comprising the fluoroelastomer blend can have a tensile strength of from about 1100 psi to 1900 psi, or from about 1200 to about 1500 psi.
In embodiments, an intermediate layer can be positioned between the substrate and fluoroelastomer blended outer layer. In other embodiments, an outer release layer can be positioned on the fluoroelastomer blended outer layer.
Examples of suitable intermediate layers or suitable optional outer release layers include silicone rubber, fluoropolymer, urethane, acrylic, titamer, ceramer, hydrofluoroelastomer, polymers, (such as polymers, copolymers, terpolymers and the like) or mixtures thereof, and fillers such as carbon black and/or aluminum oxide. In embodiments, the intermediate layer comprises a silicone rubber.
The optional intermediate layer and/or optional outer release layer can be coated to the fluoroelastomer outer layer using any known, suitable technique. In an embodiment, the additional layers can be spray or flow coated.
The intermediate layer can have a thickness of from about 2 to about 10 mm, or from about 3 to about 9 mm, or from about 5 to about 8 mm.
The outer release layer can be coated on the outer fluoroelastomer layer to a thickness of from about 1 to about 50 um, or from about 5 to about 30 um. The outer release layer can be any of the polymer coatings described above for use as the intermediate layer.
The fusing component can be of any suitable configuration. Examples of suitable configurations include a sheet, a film, a web, a foil, a strip, a coil, a cylinder, a drum, a roller, an endless strip, a circular disc, a belt including an endless belt, an endless seamed flexible belt, an endless seamless flexible belt, an endless belt having a puzzle cut seam, and the like. In an embodiment, the fuser member is a fuser roller. In embodiments, the substrate of the fuser roller is metal, such as aluminum or steel.
Optionally, any known and available suitable adhesive layer may be positioned between the fluoroelastomer outer layer and the substrate, and/or between the outer fluoroelastomer layer and the outer release layer. Examples of suitable adhesives include silanes such as amino silanes (such as, for example, HV Primer 10 from Dow Corning), titanates, zirconates, aluminates, and the like, and mixtures thereof. In an embodiment, an adhesive in from about 0.001 to about 10 percent solution can be wiped on the substrate. The adhesive layer can be coated on the substrate, or on the fluoroelastomer outer layer, to a thickness of from about 2 to about 2,000 nanometers, or from about 2 to about 500 nanometers. The adhesive can be coated by any suitable, known technique, including spray coating or wiping.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. Unless specifically recited in a claim, steps or components of claims should not be implied or imported from the specification or any other claims as to any particular order, number, position, size, shape, angle, color, or material.
The following Examples are intended to illustrate and not limit the scope herein. Parts and percentages are by weight unless otherwise indicated.
Formation of Fuser Member Coating
A fuser member coating formulation was prepared from a solvent solution/dispersion containing 100 parts by weight of a hydrofluoroelastomer, DuPont VITON® GF (a tetrapolymer of 35 weight percent vinylidenefluoride, 34 weight percent hexafluoropropylene, 29 weight percent tetrafluoroethylene, and 2 weight percent of a cure site monomer). The VITON® GF was mixed with 7 parts by weight of DuPont VITON® Curative 50, 1.5 parts by weight magnesium oxide (ElastoMag 170 Special available from Rohm and Hass, Andover Mass.), 0.75 parts by weight calcium hydroxide, 0.75 parts by weight carbon black (N990 available from R. T. Vanderbilt Co.), 4.89 parts by weight Novec® FC-4430 (available from 3M) and 0.86 parts by weight AKF-290 (available by Wacker) in a mixture of methylethylketone and methylisobutyl ketone. This coating formulation was dispensed onto a fuser roll surface via flow coating to a nominal thickness of about 20 micrometers. The coating was cured by stepwise heating in air at 95° C. for 2 hours, 175° C. for 2 hours, 205° C. for 2 hours, and 230° C. for 24 hours.
Formation of Fuser Member Coating Comprising Teflon-Filled Fluoroelastomer Blended with Unfilled-Fluoroelastomer
Fuser roll topcoat formulations were prepared identically to Example I and II except that P95930M (available from Solvay Solexis) was added. The amount of the P95930M to VITON® GF used was varied from about 3 to 30 percent by weight.
The optimum formulation, based on mechanical properties from the experiment described in Example II is about 30 percent by weight of P95930M, 5.84 pph VC-50, 2.5 pph Novec FC4432 (available from 3M), about 3.5 pph magnesium oxide, about 1.75 pph calcium hydroxide, and 0.75 pph of carbon black. The coating was cured by stepwise heating in air at 95° C. for 2 hours, 175° C. for 2 hours, 205° C. for 2 hours, and 230° C. for 24 hours.
Comparative Testing
The fuser member coatings prepared above were measured for adhesion, gloss and mechanical properties, including tensile strength, toughness, and elongation. The Example II coating has improved mechanical properties, as listed in the Table below.
It is clear from the above that Example II formulations (blend of filled-fluoroelastomer and unfilled-fluoroelastomer performed superior to that of Example 1 which just comprises a fluoroelastomer.
The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.
