Patent Application
20120282003
1. Field of Use
This disclosure is generally directed to fuser members useful in electrophotographic imaging apparatuses, including digital, image on image, and the like. In addition, the fuser member described herein can also be used in a transfix apparatus in a solid ink jet printing machine.
2. Background
In the electrophotographic printing process, a toner image can be fixed or fused upon a support (e.g., a paper sheet) using a fuser roller. Conventional fusing technologies apply release agents/fuser oils to the fuser roller during the fusing operation in order to maintain good release properties of the fuser roller. For example, oil fusing technologies have been used for all high speed products in the entry production and production color market.
Post finishing applications, such as lamination, book binding and magnetic ink character recognition (MICR) in the banking industry prints have been hindered by residual oil on the substrate. Specifically amino functionalized polydimethylsiloxane (PDMS) from the fuser roll can transfer to the substrate.
It would be desirable to have a fuser oil that does not negatively interact with post finishing applications of substrates.
In U.S. Pub. 2009/0233085, the use of nano-sized copper oxide in the fuser surface is described which mitigates certain post finishing problems. However, the use of nano-sized particles can negatively impact manufacturing cost and present environmental issues related to the handling of nano-sized particles.
According to an embodiment, there is provided a fuser member comprising a substrate and a topcoat layer disposed over the substrate. The topcoat layer comprises a fluoroelastomer cross-linked with amino silane, wherein the topcoat layer is substantially free of copper oxide. A mercapto-functionalized oil is disposed on the topcoat layer.
According to another embodiment there is provided a fuser member comprising a substrate, a resilient layer disposed on the substrate and a topcoat layer disposed on the resilient layer. The topcoat layer comprises a fluoroelastomer cross-linked with amino silane, wherein the topcoat layer is substantially free of copper oxide. A mercapto-functionalized oil is disposed on the topcoat layer.
According to another embodiment there is provided an image rendering device comprising: an image applying component for applying an image to a copy substrate; and a fusing apparatus which receives the copy substrate with the applied image from the image applying component and fixes the applied image more permanently to the copy substrate. The fusing apparatus comprises a fusing member and a pressure member which define a nip therebetween for receiving the copy substrate therethrough. The fuser member comprises a substrate and a topcoat layer disposed on the substrate comprising a fluoroelastomer cross-linked with amino silane, wherein the topcoat layer is substantially free of copper oxide. A mercapto-functionalized oil is disposed on the topcoat layer.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the present teachings and together with the description, serve to explain the principles of the present teachings.
It should be noted that some details of the figures have been simplified and are drawn to facilitate understanding of the embodiments rather than to maintain strict structural accuracy, detail, and scale.
Reference will now be made in detail to embodiments of the present teachings, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
In the following description, reference is made to the accompanying drawings that form a part thereof, and in which is shown by way of illustration specific exemplary embodiments in which the present teachings may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present teachings and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present teachings. The following description is, therefore, merely exemplary.
Illustrations with respect to one or more implementations, alterations and/or modifications can be made to the illustrated examples without departing from the spirit and scope of the appended claims. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular function. Furthermore, to the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term “comprising.” The term “at least one of” is used to mean one or more of the listed items can be selected.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of embodiments are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein are to be understood to encompass any and all sub-ranges subsumed therein. For example, a range of “less than 10” can include any and all sub-ranges between (and including) the minimum value of zero and the maximum value of 10, that is, any and all sub-ranges having a minimum value of equal to or greater than zero and a maximum value of equal to or less than 10, e.g., 1 to 5. In certain cases, the numerical values as stated for the parameter can take on negative values.
In various embodiments, the fusing or fixing member can include, for example, a substrate, with one or more functional layers formed thereon. The substrate can be formed in various shapes, e.g., a cylinder (e.g., a cylinder tube), a cylindrical drum, a belt, or a film, using suitable materials that are non-conductive or conductive depending on a specific configuration, for example, as shown in
Specifically,
In
Examples of functional layers 120 and 220 include fluorosilicones, silicone rubbers such as room temperature vulcanization (RTV) silicone rubbers, high temperature vulcanization (HTV) silicone rubbers, and low temperature vulcanization (LTV) silicone rubbers. These rubbers are known and readily available commercially, such as SILASTIC® 735 black RTV and SILASTIC® 732 RTV, both from Dow Corning; 106 RTV Silicone Rubber and 90 RTV Silicone Rubber, both from General Electric; and JCR6115CLEAR HTV and SE4705U HTV silicone rubbers from Dow Corning Toray Silicones. Other suitable silicone materials include the siloxanes (such as polydimethylsiloxanes); fluorosilicones such as Silicone Rubber 552, available from Sampson Coatings, Richmond, Va.; liquid silicone rubbers such as vinyl crosslinked heat curable rubbers or silanol room temperature crosslinked materials; and the like. Another specific example is Dow Corning Sylgard 182. Commercially available LSR rubbers include Dow Corning Q3-6395, Q3-6396, SILASTIC® 590 LSR, SILASTIC® 591 LSR, SILASTIC® 595 LSR, SILASTIC® 596 LSR, and SILASTIC® 598 LSR from Dow Corning. The functional layers provide elasticity and can be mixed with inorganic particles, for example SiC or Al2O3, as required.
For a roller configuration, the thickness of the functional layer can be from about 0.02 mm to about 10 mm, or from about 1 mm to about 8 mm, or from about 2 mm to about 7 mm. For a belt configuration, the functional layer can be from about 25 microns up to about 2 mm, or from 40 microns to about 1.5 mm, or from 50 microns to about 1 mm.
An exemplary embodiment of a release layer 130 or 230 includes a fluoroelastomer and an amino silane as a curative agent. Fluoroelastomers are from the class of 1) copolymers of two of vinylidenefluoride, hexafluoropropylene, and tetrafluoroethylene such as those known commercially as VITON A®; 2) terpolymers of vinylidenefluoride, hexafluoropropylene, and tetrafluoroethylene known commercially as VITON B®; and 3) tetrapolymers of vinylidenefluoride, hexafluoropropylene, tetrafluoroethylene, and cure site monomer known commercially as VITON GH® or VITON GF®. These fluoroelastomers are known commercially under various designations such as those listed above, along with, VITON E®, VITON E 60C®, VITON E430®, VITON 910®, ; and VITON ETP®. The VITON® designation is a trademark of E.I. DuPont de Nemours, Inc. The cure site monomer can be 4-bromoperfluorobutene-1,1,1-dihydro-4-bromoperfluorobutene-1,3-bromoperfluoropropene-1,1,1-dihydro-3-bromoperfluoropropene-1, or any other suitable, known cure site monomer, such as those commercially available from DuPont. Other commercially available fluoropolymers include FLUOREL 2170®, FLUOREL 2174®, FLUOREL 2176®, FLUOREL 2177® and FLUOREL LVS 76®, FLUOREL® being a registered trademark of 3M Company. Additional commercially available materials include AFLAS™ a poly(propylene-tetrafluoroethylene), and FLUOREL II® (LII900) a poly(propylene-tetrafluoroethylenevinylidenefluoride), both also available from 3M Company, as well as the Tecnoflons identified as FOR-60KIR®, FOR-LHF®, NM® FOR-THF®, FOR-TFS®, TH®, NH®, P757®, TNS®, T439®, PL958®, BR9151® and TN505®, available from Ausimont.
The fluoroelastomers VITON GH® and VITON. GF® have relatively low amounts of vinylidenefluoride. The VITON GF® and VITON GH® have about 35 weight percent of vinylidenefluoride, about 34 weight percent of hexafluoropropylene, and about 29 weight percent of tetrafluoroethylene, with about 2 weight percent cure site monomer.
The amino silane as a curative agent is present, in embodiments, in an effective amount of, for example, from about 0.5 to about 10 percent (weight percent) based on the weight of fluoroelastomer. In embodiments, the amino silane is present in an amount of from about 1 to about 5 percent. In embodiments, the amino silane is present in an amount of from about 1 to about 2 percent based on the weight of fluoroelastomer.
The amino silane is of the general formula NH2(CH2)nNH2(CH2)mSi((OR)t(R′)w) wherein n and m are numbers from about 1 to about 20, or from about 2 to about 6; t+w=3; R and R′ are the same or different and are an aliphatic group of from about 1 to about 20 carbon atoms, such as methyl, ethyl, propyl, butyl, and the like, or an aromatic group of from about 6 to about 18 carbons, for example, benzene, tolyl, xylyl, and the like. Examples of amino silanes include 4-aminobutyldimethyl methoxysilane, 4-aminobutyl triethoxysilane, (aminoethylaminomethyl)phenyl triethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyl dimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl tris(2-ethyl-hexoxy)silane, N-(6-aminohexyl)aminopropyl-trimethoxysilane, 3-(1-aminopropoxy)-3,3-dimethyl-1-propenyl-trimethoxysilane, 3-aminopropyl tris(methoxyethoxyethoxy)-silane, 3-aminopropyldimethyl ethoxysilane, 3-aminopropylmethyl diethoxysilane, 3-aminopropyl diisopropylethoxysilane, 3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, or 3-aminopropyltris(trimethylsiloxy)silane. In embodiments amino silanes are AO700 (N-(2-aminoethyl)-3-aminopropyl trimethoxysilane), 3-(N-styrylmethyl-2-aminoethyl aminopropyl)trimethoxy silane, sold in its hydrochloride form, and (aminoethyl aminomethyl)phenyl trimethoxy silane all manufactured by Huls of America, Inc. The release layer 130 or 230 is substantially free of copper oxide.
In U.S. Pub. 2009/0233085, the use of nano-sized copper oxide in the fuser surface is described which mitigates certain post finishing problems. However, the use of nano-sized particles increases manufacturing cost by adding a raw material. The disclosure described herein eliminates the requirement of copper oxide particles. Providing a fluorelastomer topcoat cross linked with amino silane layer that is substantially free of copper oxide eliminates a material from the topcoat. Substantially free in the context of the topcoat layer means less than about 0.01 weight percent of copper oxide in the topcoat layer, or less than 0.005 weight percent of copper oxide in the topcoat layer, or less than 0.001 weight percent copper oxide in the topcoat layer.
For the fuser member 200, the thickness of the outer surface layer or release layer 230 can be from about 10 microns to about 100 microns, or from about 20 microns to about 80 microns, or from about 40 microns to about 60 microns.
Additives and additional conductive or non-conductive fillers may be present in the intermediate layer substrate layers 110 and 210, the intermediate layers 120 and 220 and the release layers 130 and 230. In various embodiments, other filler materials or additives including, for example, inorganic particles, can be used for the coating composition and the subsequently formed surface layer. Conductive fillers used herein may include carbon blacks such as carbon black, graphite, fullerene, acetylene black, fluorinated carbon black, and the like; carbon nanotubes; metal oxides and doped metal oxides, such as tin oxide, antimony dioxide, antimony-doped tin oxide, titanium dioxide, indium oxide, zinc oxide, indium oxide, indium-doped tin trioxide, and the like; and mixtures thereof. Certain polymers such as polyanilines, polythiophenes, polyacetylene, poly(p-phenylene vinylene), poly(p-phenylene sulfide), pyrroles, polyindole, polypyrene, polycarbazole, polyazulene, polyazepine, poly(fluorine), polynaphthalene, salts of organic sulfonic acid, esters of phosphoric acid, esters of fatty acids, ammonium or phosphonium salts and mixtures thereof can be used as conductive fillers. The fillers are present in the topcoat or release layer in an amount of from about 0.1 weight percent to about 50 weight percent based on the total weight of the release layer or outer surface layer. In embodiments, the fillers are present in an amount of from about 0.5 weight percent to about 20 weight percent or from about 1 weight percent to about 10 weight percent based on the total weight of the topcoat layer In various embodiments, other additives known to one of ordinary skill in the art can also be included to form the disclosed composite materials.
Optionally, any known and available suitable adhesive layer may be positioned between the outer layer or outer surface, the functional layer and the substrate. The adhesive layer can be coated on the substrate, or on the outer layer, to a thickness of from about 2 nanometers to about 10,000 nanometers, or from about 2 nanometers to about 1,000 nanometers, or from about 2 nanometers to about 5000 nanometers. The adhesive can be coated by any suitable known technique, including spray coating or wiping.
When using a fluoroelastomer as the outer surface of a fuser member, a liquid 140 (
The presence of an aminosilane curing agent, such as AO700, promotes a chemical event or events enabling wetting of the fluoroelastomeric surface. Non-bonding interactions occur at the surface. As mentioned previously, the amino silane is of the general formula NH2(CH2)nNH2(CH2)mSi((OR)t(R′)w) wherein n and m are numbers from about 1 to about 20, or from about 2 to about 6; t+w=3; R and R′ are the same or different and are an aliphatic group of from about 1 to about 20 carbon atoms, such as methyl, ethyl, propyl, butyl, and the like, or an aromatic group of from about 6 to about 18 carbons, for example, benzene, tolyl, xylyl, and the like.
Using an organo functionality in the release oil, such as the mercapto-functionalized PDMS oil can alleviate this problem.
Shown in Structure 1 below is a PDMS release oil having amino functionality. This is referred to as fuser fluid in the examples.
wherein R is CH3, an alkyl group or aryl group, Z is amino propyl (CH2CH2CH2NH2), and the ratio of a:b is from about 1:1 to about 2000:1.
Shown in Structure 2 below is a mercapto-functionalized PDMS release oil. This is referred to as fuser agent in the Examples.
wherein R is CH3, and alkyl group or and aryl group, Z is (CH2)nSH where n is from about 1 to about 20, or from about 2 to about 10 or from about 3 to about 5, the ratio of a:b is from about 1:1 to about 2000:1.
Scheme 1 shows a proposed mechanism for thiol groups of mercapto fluid binding to fluoroelastomer chains cured with an aminosilane (Viton).
The presence of residual primary and secondary amines from aminosilane at the fluoroelastomer topcoat surface, at high temperature, can result in deprotonation of the thiol to yield the basic thiolate group. The thiolate undergoes nucleophilic addition of residual double bonded positions on the Viton chains, where 1,4 nucleophilic addition of the conjugate formed by amino crosslinking is especially favorable. In this system, the amino groups of the aminosilane coupler act as both the base to produce a thiolate, and its presence via crosslinking as a conjugate along the fluoroelastomer chain promotes reaction at the surface. Mercapto fluid and aminosilane function together in the system to enable wetting.
Switching the release oil for a fuser topcoat of fluoroelastomer cured with an aminosilane results in a change in chemistry that leads to a difference in binding the thiol group on the mercapto fluid to allow a similar barrier to form on the fuser surface. This provides adequate release of the toner and prevents rapid contamination build up of the release oil, which can cause release failure and other failure modes that cause short fuser roller life to customers. The result is significantly improved adhesion in a book-binding test using a standard glue, such as EVA based hot melt adhesives, US661, Dowell 983, EXP. A, Bourg 3002, Reynolds 025 and 029, Henkel US-703, as the substrate lacks amino groups from the release oil.
Specific embodiments will now be described in detail. These examples are intended to be illustrative, and not limited to the materials, conditions, or process parameters set forth in these embodiments. All parts are percentages by solid weight unless otherwise indicated.
Tests were conducted to verify the use of organo-functionalized siloxane release oils used with fluoroelastomeric topcoats cured with an amino silane. An exemplary bisphenol curing agent can include VITON® Curative No. 50 (VC-50) available from E. I. du Pont de Nemours, Inc. Curative VC-50 can contain Bisphenol-AF as a cross-linker and diphenylbenzylphosphonium chloride as an accelerator. Bisphenol-AF is also known as 4,4′-(hexafluoroisopropylidene)diphenol. VC-50 cured roller topcoats fail after less than 1,000 sheets through the fuser from lack of release. In the case of AO700 cured roller topcoats (fluoroelastomer cured with amino silane), release was excellent all the way to the end of a 25,000 sheet test running different color stripes at various toner mass (monolayer C,M,Y,K and trilayer process black). Release agents or oil transferred to sheet was slightly lower for the mercapto oil, although no streaking or other oil-caused print defects were observed in this test.
Amino-functionalized oil prevents the glue from sticking to the sheet, resulting in a fiber-tear rating of 0. With a similar amount of mercapto-functionalized oil (Table 1) transferred to the substrate (Productolith C1S Cover, uncoated side) the amount of fiber tear is markedly improved. (Table 2)
The following FTIR data (Table 3) is indicative of the surface reactivity of the AO700-crosslinked fluoroelastomer composition with a variety of solutions. The following release agents were reacted with the fluoroelastomer-aminosilane cured topcoat material described herein.
These solution treatments are either actual polydimethylsiloxane release agents used in electrophotographic printing systems, or analog release agents thereof. The release agents were applied to the fuser topcoat surface, heated and rinsed with hexane. The measurements were made with ATR (Attenuated Total Reflectance) FT-IR. The asymmetric CH2 stretch ratio of 2926 cm−1/1396 cm−1 represents the relative amount of attached alkane after the treatment, while the asymmetric CH3 stretch ratio of 2926 cm−1/1396 cm−1 represents the relative amount of PDMS attached after the treatment.
The data in
Print gloss was unaffected; samples fused with Amino Oil on VC50 fuser rollers were statistically similar to mercapto oil on an AO700 Roll as shown in
Fuser contamination of the usual contaminants, PDMS gel, XP777 resin, PY-17 Pigment and Zinc Fumarate for the AO700/mercapto-oil roller after 25 kp was similar to or less than the VC50/Amino-oil roller. (
It will be appreciated that variants of the above-disclosed and other features and functions or alternatives thereof may be combined into other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art, which are also encompassed by the following claims.
