Coated fuser members

Coated fuser members such as a fuser roller, pressure roller, or fuser belt are coated with a release coating comprises an outermost layer of fluoropolymer resin powder directly bonded to an underlying fluoroelastomer layer.

FIELD OF THE INVENTION 
This invention relates to electrostatographic apparatus and coated fuser 
members and methods of making coated fuser members. More particularly, 
this invention relates to an improved multi-layer coating for fuser 
members and the method of making the multi-layer coated fuser members. 
BACKGROUND OF THE INVENTION 
Known to the electrostatographic fixing art are various fuser members 
adapted to apply heat and pressure to a heat-softenable 
electrostatographic toner on a receiver, such as paper, to permanently 
fuse the toner to the receiver. Examples of fuser members include fuser 
rollers, pressure rollers, fuser plates and fuser belts for use in fuser 
systems such as fuser roller systems, fuser plate systems and fuser belt 
systems. 
One of the long-standing problems with electrostatographic fusing systems 
is the adhesion of the heat-softened toner particles to the surface of a 
fuser member and not to the receiver, known as offset, which occurs when 
the toner-bearing receiver is passed through a fuser system. There have 
been several approaches to decrease the amount of toner offset onto fuser 
members. One approach has been to make the toner-contacting surface of a 
fuser member, for example, a fuser roller and/or pressure roller of a 
non-adhesive (non-stick) material. 
One known non-adhesive coating for fuser members comprises fluoropolymer 
resins, but fluoropolymer resins are non-compliant. It is desirable to 
have compliant fuser members to increase the contact area between a fuser 
member and the toner-bearing receiver. However, fuser members with a 
single compliant rubber layer absorb release oils and degrade in a short 
time leading to wrinkling artifacts, non-uniform nip width and toner 
offset. To make fluoropolymer resin coated fuser members with a compliant 
layer, U.S. Pat. Nos. 3,435,500 and 4,789,565 disclose a fluoropolymer 
resin layer sintered to a silicone rubber layer which is adhered to a 
metal core. In U.S. Pat. No. 4,789,565, an aqueous solution of 
fluoropolymer resin powder is sintered to the silicone rubber layer. In 
U.S. Pat. No. 3,435,500, a fluoropolymer resin sleeve is sintered to the 
silicone rubber layer. Sintering of the fluoropolymer resin layer is 
usually accomplished by heating the coated fuser members to temperatures 
of approximately 500.degree. C. Such high temperatures can have a 
detrimental effect on the silicone rubber layer causing the silicone 
rubber to smoke or depolymerize, which decreases the durability of the 
silicone rubbers and the adhesion strength between the silicone rubber 
layer and the fluoropolymer resin layer. Attempts to avoid the detrimental 
effect the high sintering temperatures have on the silicone rubber layer 
have been made by using dielectric heating of the fluoropolymer resin 
layer, for example see U.S. Pat. Nos. 5,011,401 and 5,153,660. Dielectric 
heating is, however, complicated and expensive and the fluoropolymer resin 
layer may still delaminate from the silicone rubber layer when the fuser 
members are used in high pressure fuser systems. In addition, a fuser 
member made with a fluoropolymer resin sleeve layer possesses poor 
abrasion resistance and poor heat resistance. 
For the foregoing reasons, there is a need for fuser members and a method 
of fabricating fuser members which have a fluoropolymer resin layer, and 
compliant layer or layers, exhibiting improved adhesion between their 
constituent layers, improved abrasion resistance, improved heat resistance 
and the ability to be made more economically. 
SUMMARY OF THE INVENTION 
The fuser members of this invention comprise, in order, a support; a 
fluoroelastomer layer; and a fluoropolymer resin layer directly on said 
fluoroelastomer layer. Further, this invention includes the method of 
making the coated fuser members which comprises the steps of applying to a 
support a fluoroelastomer layer; applying to the fluoroelastomer layer a 
fluoropolymer resin powder; and sintering the fluoropolymer resin powder 
to form a fluoropolymer resin layer. 
The fuser members of this invention have good non-adhesiveness to toner, 
abrasion resistance, heat resistance and adhesion between the layers. 
There is little or no deterioration of the layers or of the adhesion 
between the layers during the sintering step of the process, because the 
fluoroelastomer layer, and fluoropolymer resin layer have good heat 
resistance. Further, the fuser member and method of this invention do not 
use primers between the fluoroelastomer layer and the fluoropolymer resin 
powder layer which simplifies the method of making the fuser member, and 
surprisingly provides excellent adhesion between the fluoroelastomer layer 
and the fluoropolymer resin powder layer. 
DESCRIPTION OF THE INVENTION 
The fuser member of this invention comprises, in order, a support; a 
fluoroelastomer layer; and directly thereon a fluoropolymer resin layer. 
In preferred embodiments of the invention, the bonds between the 
fluoropolymer resin layers, and fluoroelastomer layers are very strong, 
making it very difficult to peel the layers apart. 
The term "fuser member" is used herein to identify one of the elements of a 
fusing system. The fuser member can be a pressure or fuser plate, pressure 
or fuser roller, a fuser belt or any other member on which a release 
coating is desirable. Commonly, the fuser member is a fuser roller or 
pressure roller and the discussion herein may refer to a fuser roller or 
pressure roller, however, the invention is not limited to any particular 
configuration of fuser member. 
The support for the fuser member can be a metal element with or without 
additional layers adhered to the metal element. The metal element can take 
the shape of a cylindrical core, plate or belt. The metal element can be 
made of, for example, aluminum, stainless steel or nickel. The surface of 
the metal element can be rough, but it is not necessary for the surface of 
the metal element to be rough to achieve good adhesion between the metal 
element and the layer attached to the metal element. The additional 
support layers adhered to the metal element comprise of one or more layers 
of materials useful for fuser members, such as, silicone rubbers, 
fluoroelastomers and primers. 
In one preferred embodiment of the invention, the support comprises a metal 
element coated with an adhesion promoter layer. The adhesion promoter 
layer can be any commercially available material known to promote the 
adhesion between fluoroelastomers and metal, such as silane coupling 
agents, which can be either epoxy-functionalized or amine-functionalized, 
epoxy resins, benzoguanamineformaldehyde resin crosslinker, epoxy cresol 
novolac, dianilinosulfone crosslinker, polyphenylene sulfide polyether 
sulfone, polyamide, polyimide and polyamide-imide. Preferred adhesion 
promoters are epoxy-functionalized silane coupling agents. The most 
preferable adhesion promoter is a dispersion of THIXON 300, THIXON 311 and 
triphenylamine in methyl ethyl ketone. The THIXON materials are supplied 
by Morton Chemical Co.. 
In another preferred embodiment of the invention, the support consists of a 
metal element with one or more base cushion layers. The base cushion layer 
or layers can consist of known materials for fuser member layers such as, 
one or more layers, which may be the same or different of silicone 
rubbers, fluorosilicone rubbers, or any of the same materials that can be 
used to form fluoroelastomer layers. Preferred silicone rubber layers 
consist of polymethyl siloxanes, such as EC-4952, sold by Emerson Cummings 
or SILASTIC J or E sold by Dow Corning. Preferred fluorosilicone rubbers 
include polymethyltrifluoropropylsiloxanes, such as SYLON Fluorosilicone 
FX11293 and FX11299 sold by 3M. 
The base cushion layer may be adhered to the metal element via a base 
cushion primer layer. The base cushion primer layer can comprise a primer 
composition which improves adhesion between the metal element and the 
material used for the base cushion layer. If the base cushion layer is a 
fluoroelastomer material, the adhesion promoters described above can be 
used as the base cushion primer layer. Other primers for the application 
of fluorosilicone rubbers and silicone rubbers to the metal element are 
known in the art. Such primer materials include silane coupling agents, 
which can be either epoxy-functionalized or amine-functionalized, epoxy 
resins, benzoguanamineformaldehyde resin crosslinker, epoxy cresol 
novolac, dianilinosulfone crosslinker, polyphenylene sulfide polyether 
sulfone, polyamide, polyimide and polyamide-imide. 
The inclusion of a base cushion layer on the metal element of the support 
increases the compliancy of the fuser member. By varying the compliancy, 
optimum fuser members and fuser systems can be produced. The variations in 
the compliancy provided by optional base cushion layers are in addition to 
the variations provided by just changing the thickness or materials used 
to make the fluoroelastomer layer and/or fluoropolymer resin layer. The 
presently preferred embodiment in a fuser roller system is to have a very 
compliant fuser roller and a non-compliant or less compliant pressure 
roller. In a fuser belt system it is preferred to have a compliant 
pressure roller and a non-compliant or less compliant belt. Although the 
above are the presently preferred embodiments, fuser systems and members 
including plates, belts and rollers can be made in various configurations 
and embodiments wherein at least one fuser member is made according to 
this invention. 
The fluoroelastomer layer can comprise copolymers of vinylidene fluoride 
and hexafluoropropylene, copolymers of tetrafluoroethylene and propylene, 
terpolymers of vinylidene fluoride, hexafluoropropylene and 
tetrafluoroethylene, terpolymers of vinylidene fluoride, 
tetrafluoroethylene and perfluoromethylvinylethyl, and terpolymers of 
vinylidene fluoride, tetrafluoroethylene, and perfluoromethylvinylether. 
Specific examples of fluoroelastomers which are useful in this invention 
are commercially available from E. I. DuPont de Nemours and Company under 
the trade names KALREZ, and VITON A, B, G, GF and GLT, and from 3M Corp. 
under the trade names FLUOREL FC 2174,2176 and FX 2530 and AFLAS. 
Additional vinylidene fluoride based polymers useful in the 
fluoroelastomer layer are disclosed in U.S. Pat. No. 3,035,950, the 
disclosure of which is incorporated herein by reference. Mixtures of the 
foregoing fluoroelastomers may also be suitable. Although it is not 
critical in the practice of this invention, the number-average molecular 
weight range of the fluoroelastomers may vary from a low of about 10,000 
to a high of about 200,000. In the preferred embodiments, vinylidene 
fluoride-based fluoroelastomers have a number-average molecular weight 
range of about 50,000 to about 100,000. 
A preferable material for the fluoroelastomer layer is a compounded mixture 
of a fluoroelastomer polymer, a curing material, and optional fillers. The 
curing material can consist of curing agents, crosslinking agents, curing 
accelerators and fillers or mixtures of the above. Suitable curing agents 
for use in the process of the invention include the nucleophilic addition 
curing agents as disclosed, for example, in the patent to Seanor, U.S. 
Pat. No. 4,272,179, incorporated herein by reference. Exemplary of a 
nucleophilic addition cure system is one comprising a bisphenol 
crosslinking agent and an organophosphonium salt as accelerator. Suitable 
bisphenols include 2,2-bis(4-hydroxyphenyl) hexafluoropropane, 
4,4-isopropylidenediphenol and the like. Although other conventional cure 
or crosslinking systems may be used to cure the fluoroelastomers useful in 
the present invention, for example, free radical initiators, such as an 
organic peroxide, for example, dicumylperoxide and dichlorobenzoyl 
peroxide, or 2,5-dimethyl-2,5-di-t-butylperoxyhexane with triallyl 
cyanurate, the nucleophilic addition system is preferred. Suitable curing 
accelerators for the bisphenol curing method include organophosphonium 
salts, e.g., halides such as benzyl triphenylphosphonium chloride, as 
disclosed in U.S. Pat. No. 4,272,179 cited above. 
The fluoroelastomer can include inert filler. Inert fillers are frequently 
added to polymeric compositions to provide added strength and abrasion 
resistance to a surface layer. In the fluoroelastomer layer of the fuser 
member of this invention, inclusion of the inert filler is optional. 
Omission of the inert filler does not reduce the adhesive strength of the 
fluoroelastomer layer. Suitable inert fillers which are optionally used 
include mineral oxides, such as alumina, silica, titania, and carbon of 
various grades. 
Nucleophilic addition-cure systems used in conjunction with 
fluoroelastomers can generate hydrogen fluoride and thus acid acceptors 
may be added as fillers. Suitable acid acceptors include Lewis acids such 
as lead oxide, magnesium oxide, such as MAGLITE D and Y supplied by Merck 
& Co., calcium hydroxide, such as C-97, supplied by Fisher Scientific Co., 
zinc oxide, copper oxide, tin oxide, iron oxide and aluminum oxide which 
can be used alone or as mixtures with the aforementioned inert fillers in 
various proportions. The most preferable fluoroelastomer layer material 
comprises a compounded mixture of 100 parts VITON A, from 2 to 9 parts 
2,2-bis(4-hydroxyphenyl) hexafluoropropane, commercially available as CURE 
20, from 2 to 10 parts benzyl triphenylphosphonium chloride, commercially 
available as CURE 30, from 5 to 30 parts lead oxide and from 0 to 30 parts 
THERMAX (carbon black), mechanically compounded at room temperature on a 
two roll mill until it forms a uniform mixture. CURE 20 and CURE 30 are 
products of DuPont Co. THERMAX is a product of R. T. Vanderbilt Co., Inc.. 
This compounded mixture can either be compression molded onto the support, 
or dispersed in solvent for dip-, ring- or spray-coating onto the support. 
If ring-coating is used to apply this compounded mixture to the support, 
then it is preferable to add a small amount of aminosiloxane polymer to 
the formulation described above. For additional information on this 
fluoroelastomer composite material, see U.S. Pat. No. 4,853,737, which is 
incorporated herein by reference. 
The fluoroelastomer layer can also comprise an interpenetrating network of 
fluoroelastomer and a silicone polymer. An interpenetrating network 
coating composition can be obtained by mechanically compounding 
fluoroelastomer polymer, functionalized siloxane, fluorocarbon curing 
materials and optional acid acceptors or other fillers to form a uniform 
mixture suitable for compression molding or dip-, ring-, or spray-coating 
after dispersing the composite in a solvent. The fluoroelastomer polymers, 
curing materials, curing agents, curing accelerators, acid acceptors and 
other fillers can be selected from those previously described above. The 
functionalized siloxane is preferably a polyfunctional poly(C.sub.1-6 
alkyl)phenyl siloxane or polyfunctional poly(C.sub.1-6 alkyl)siloxane. 
Preferred siloxanes are heat-curable, however peroxide-curable siloxanes 
can also be used with conventional initiators. Heat curable siloxanes 
include the hydroxy-functionalized organopolysiloxanes belonging to the 
classes of silicones known as "hard" and "soft" silicones. Preferred hard 
and soft silicones are silanol-terminated polyfunctional 
organopolysiloxanes. 
Exemplary hard and soft silicones are commercially available or can be 
prepared by conventional methods. Examples of commercially available 
silicones include DC6-2230 silicone and DC-806A silicone (sold by Dow 
Corning Corp.), which are hard silicone polymers, and SFR-100 silicone 
(sold by General Electric Co.) and EC-4952 silicone (sold by Emerson 
Cummings Co.), which are soft silicone polymers. DC6-2230 silicone is 
characterized as a silanol-terminated polymethyl-phenylsiloxane copolymer 
containing phenyl to methyl groups in a ratio of about 1 to 1, 
difunctional to trifunctional siloxane units in a ratio of about 0.1 to 1 
and having a number-average molecular weight between 2,000 and 4,000. 
DC-806A silicone is characterized as a silanol-terminated 
polymethylphenylsiloxane copolymer containing phenyl to methyl groups in a 
ratio of about 1 to 1 and having difunctional to trifunctional siloxane 
units in a ratio of about 0.5 to 1. SFR-100 silicone is characterized as a 
silanol- or trimethylsilyl-terminated polymethylsiloxane and is a liquid 
blend comprising about 60 to 80 weight percent of a difunctional 
polydimethylsiloxane having a number-average molecular weight of about 
90,000 and 20 to 40 weight percent of a polymethylsilyl silicate resin 
having monofunctional (i.e. SiO.sub.2) repeating units in an average ratio 
of between about 0.8 and 1 to 1, and having a number-average molecular 
weight of about 2,500. EC-4952 silicone is characterized as a 
silanol-terminated polymethylsiloxane having about 85 mole percent of 
difunctional dimethylsiloxane repeating units, about 15 mole percent of 
trifunctional methylsiloxane repeating units and having a number-average 
molecular weight of about 21,000. 
Preferred fluoroelastomer-silicone interpenetrating networks have ratios of 
silicone to fluoroelastomer polymer between about 0.1 and 1 to 1 by 
weight, preferably between about 0.2 and 0.7 to 1. The interpenetrating 
network is preferably obtained by mechanically compounding, for example, 
on a two-roll mill a mixture comprising from about 40 to 70 weight percent 
of a fluoroelastomer polymer, from 10 to 30 weight percent of a curable 
polyfunctional poly(C.sub.1-6 alkyl)phenylsiloxane or poly(C.sub.1-6 
alkyl)siloxane polymer, from 1 to 10 weight percent of a curing agent, 
from 1 to 3 weight percent of a curing accelerator, from 5 to 30 weight 
percent of an acid acceptor type filler, and from 0 to 30 weight percent 
of an inert filler. 
When a fluoroelastomer-silicone interpenetrating network is the 
fluoroelastomer layer material, the support is coated by conventional 
techniques, usually by compression molding or spray-, ring-, or 
dip-coating. The solvents used for solvent coating include polar solvents, 
for example, ketones, acetates and the like. Preferred solvents for the 
fluoroelastomer based interpenetrating networks are the ketones, 
especially methyl ethyl ketone and methyl isobutyl ketone. The dispersions 
of the interpenetrating networks in the coating solvent are at 
concentrations usually between about 10 to 50 weight percent solids, 
preferably between about 20 to 30 weight percent solids. The dispersions 
are coated on the support to give a 10 to 100 micrometer thick sheet when 
cured. 
Curing of the interpenetrating network is carried out according to the well 
known conditions for curing fluoroelastomer polymers ranging, for example, 
from about 12 to 48 hours at temperatures of between 50.degree. C. to 
250.degree. C. Preferably, the coated composition is dried until solvent 
free at room temperature, then gradually heated to about 230.degree. C. 
over 24 hours, then maintained at that temperature for 24 hours. 
Additional information on fluoroelastomer-silicone polymer interpenetrating 
networks can be found in U.S. Pat. No. 5,582,917 filed Sep. 16, 1993, 
which is a continuation of U.S. application Ser. No. 940,929, filed Sep. 
4, 1992. These three patent applications are assigned to the Eastman Kodak 
Co., and are incorporated herein by reference. 
The fluoropolymer resin layer comprises a sintered fluoropolymer resin 
powder, such as semicrystalline fluoropolymer or a semicrystalline 
fluoropolymer composite. Such fluoropolymer resin powder materials include 
polytetrafluoroethylene (PTFE) powder, polyperfluoroalkoxy (PFA) powder, 
polyfluorinated ethylene-propylene (FEP) powder, 
poly(ethylenetetrafluoroethylene) powder, polyvinylfluoride powder, 
polyvinylidene fluoride powder, poly(ethylene-chloro-trifluoroethylene) 
powder, polychlorotrifluoroethylene powder, and mixtures and copolymers of 
fluoropolymer resin powders. Some of these fluoropolymer resin powders are 
commercially available from DuPont as TEFLON or SILVERSTONE materials, and 
from Whitford as DYKOR materials. 
The fluoropolymer resin powders are dry, solventless, solid particles. The 
fluoropolymer resin powders can be prepared by mechanically grinding a 
fluoropolymer resin to form the powder. Methods for forming fluoropolymer 
resin powders have been previously disclosed in the prior art. For 
example, PTFE powder can be prepared by polymerizing tetrafluoroethylene 
in an aqueous medium with an initiator and emulsifying agent, the PETE is 
separated from the aqueous medium and dried, and then mechanically ground 
to produce fine particulate. For additional description on making 
fluoropolymer resin powders, see U.S. Pat. No. 2,612,484, and Encyclopedia 
of Polymer Science and Engineering, Vol. 16, 2nd Ed., pp 577-599 (John 
Wiley & Sons 1989) incorporated herein by reference. 
The preferred fluoropolymer resin powders used to make the fluoropolymer 
resin layer are PFA, and FEP. The preferred PFA is commercially available 
from Whitford as DYKOR 810 and from DuPont as PFA-532-5011. The preferred 
FEP is available from DuPont as FEP-532-8000. The particle size of the 
fluoropolymer resin powders are preferably from 10 microns to 60 microns, 
more preferably from 15 microns to 50 microns, most preferably from from 
20 microns to 40 microns. 
The fluoropolymer resin powder is preferably applied to the fluoroelastomer 
layer by a dry, that is a solventless application method. Examples of 
solventless application methods include molding, and electrostatic powder 
spray coating. The preferred method is electrostatic powder spray coating, 
which preferably is accomplished by dispersing the fluoropolymer resin 
powder in a gas stream, passing the powder through a high voltage field 
inorder to apply an electrostatic charge to the powder, grounding the 
support having the fluoroelastomer layer and spraying the charged powder 
at the fluoroelastomer layer thereby causing the charged powder to 
electrostatically adhere to the fluoroelastomer layer. Preferably, the 
resulting fuser member comprising the support, fluoroelastomer layer and 
electrostatically adhered fluoropolymer resin powder layer is then placed 
into an oven at a temperature and time sufficient to sinter the 
fluoropolymer resin powder to the fluoroelastomer layer. Typically, 
fluoropolymer resin powders are sintered at 270.degree. C. to 350.degree. 
C. for 10 minutes to 1 hour. 
Electrostatic spray systems useful for this method are availble from 
Nordson Corp and other suppliers. Additional information on electrostatic 
powder spray coating is available in the prior art, for example, see 
Encyclopedia of Chemical Technology, Vol. 19, pp 1-25 (John Wiley & Sons 
1982), incorporated herein by reference. 
The surface roughness of the fluoropolymer resin powder layer is preferably 
from 0.25 to 2.5 microns (10 to 100 micoinch), more preferably from 0.5 to 
2 microns (20 to 80 microinch) and most preferably from 1 to 1.75 microns 
(40 to 70 microinch). The surface roughness can be measured using a 
Federal Surface Analyzer, System 4000, having a sapphire chisel stylus 
with a radius of 10 .mu.m. The preferred fuser members made by the 
preferred methods of this invention typically have a greater surface 
roughness than fuser members made by heat-shrinking fluoropolymer sleeves 
or by other methods of applying fluoropolymer resins to fuser members. 
The thicknesses of the layers of the fuser members of this invention can 
vary depending on the desired compliancy or noncompliancy of a fuser 
member. The preferred thicknesses of the layers for a fuser member having 
a base cushion layer as part of the support are as follows: the base 
cushion primer layer may be from 2.5 to 25 microns (0.1 to 1 mils); the 
base cushion layer may be from 25 microns to 10 mm (1 to 400 mils), the 
fluoroelastomer layer may be from 25 microns to 10 mm (1 to 400 mils); and 
the fluoropolymer resin layer may be from 25 to 75 microns (1 to 3 mils). 
The preferable thicknesses for the layers of a fuser member with no base 
cushion layer as part of the support are as follows: the adhesion promoter 
may be from 7.5 to 25 microns (0.3 to 1 mils); the fluoroelastomer layer 
may be from 25 micons to 10 mm (1 to 400 mils); and the fluoropolymer 
resin layer may be from 25 to 75 microns (1.0 to 3 mils). In both 
embodiments, more preferably the fluoropolymer resin layer has a thickness 
from 25 to 50 micons (1 to 2 mils). 
The compositions of the above-described layers of the fuser member may 
optionally contain additives or fillers such as aluminum oxide, iron 
oxide, magnesium oxide, silicon dioxide, titanium dioxide, calcium 
hydroxide, lead oxide, zinc oxide, copper oxide and tin oxide to increase 
the thermal conductivity or the hardness of the layers. Pigments may be 
added to affect the color. Optional adhesive materials and dispersants may 
also be added. 
The coated fuser member of this invention having a support can be made by 
the following steps: applying to the support a fluoroelastomer layer; 
coating the fluoroelastomer layer with a powder fluoropolymer resin layer; 
and sintering the fluoropolymer resin layer. 
In one embodiment of the invention, the support consists of a metal element 
and an adhesion promoter for a fluoroelastomer layer. In another 
embodiment of the invention the support consists of a primer layer and one 
or more base cushion layers with additional primer layers between the base 
cushion layers where necessary. The methods of making some of the 
embodiments of this invention will be described in more detail. 
The fuser member without a base cushion layer can be prepared as follows: 
Firstly, the support is prepared. A metal element is cleaned and dried. Any 
commercial cleaner or known solvent, for example isopropyl alcohol, which 
will remove grease, oil and dust can be used for this purpose. The support 
is further prepared by applying to the metal element the adhesion promoter 
layer. The adhesion promoter may be applied to the metal element by any 
method which provides a uniform coating. Examples of such methods include 
wiping, brushing, or spray-, ring- or dip-coating the material onto the 
metal support. The adhesion promoter is dried and cured typically in an 
oven at temperatures between about 160 and 176.degree. C. (320.degree. F. 
and 350.degree. F.). Secondly, the fluoroelastomer layer is applied to the 
primer layer usually by compression-molding, extrusion-molding, or blade-, 
spray-, ring- or dip-coating the fluoroelastomer layer onto the support. 
The fluoroelastomer layer is then cured typically in an oven at 
temperatures between about 198 and 260.degree. C. (390.degree. F. and 
500.degree. F.). Thirdly, the fluoropolymer resin powder layer is applied 
to the fluoroelastomer layer. Preferably, the fluoropolymer resin powder 
layer is applied by electrostatic powder spray-coating. Fifthly, the fuser 
member is placed in an oven typically at temperatures between about 316 
and 427.degree. C. (600.degree. F. and 800.degree. F.) to sinter the 
fluoropolymer resin layer. (The specified temperature ranges can vary 
depending upon the material to be cured and the curing time.) 
Other embodiments of the invention have a base cushion layer as part of the 
support. For example, to make a coated fuser member with a support 
consisting of a metal element, silicone rubber primer layer, and a 
condensation cure silicone rubber layer, and then the fluoroelastomer 
layer, and fluoropolymer resin powder layer, the method is as follows: 
Firstly, the metal element is cleaned and dried as described earlier. 
Secondly, the metal element is coated with a layer of a known silicone 
rubber primer, selected from those described earlier. A preferred primer 
for a condensation cure silicone rubber base cushion layer is GE 4044 
supplied by General Electric. Thirdly, the silicone rubber layer is 
applied by an appropriate method, such as, blade-coating, ring-coating, 
injection-molding or compression-molding the silicone rubber layer onto 
the silicone rubber primer layer. A preferred condensation cure 
polydimethyl siloxane is EC-4952 produced by Emerson Cummings. Fourthly, 
the silicone rubber layer is cured, usually by heating it to temperatures 
typically between 210 and 232.degree. C. (410.degree. F. and 450.degree. 
F.) in an oven. Fifthly, the silicone rubber layer undergoes corona 
discharge treatment usually at about 750 watts for 90 to 180 seconds. From 
here the process of applying and curing the fluoroelastomer layer, and 
fluoropolymer resin powder layer described above is followed. 
In yet other embodiments of the invention with a base cushion layer as part 
of the support, the process is modified as follows. If the base cushion 
layer is an addition cure silicone rubber, the preferred silicone primer 
DC-1200 supplied by Dow Corning is applied to the metal element. Then, the 
addition cure silicone rubber is applied, for example, by 
injection-molding. The silicone rubber layer is then cured. If the base 
cushion layer is a fluorosilicone elastomer, the metal element is primed 
with a known silicone primer, then the fluorosilicone elastomer layer is 
applied, usually by compression-molding and cured. If a 
fluoroelastomer-silicone interpenetrating network or other additional 
fluoroelastomer material is used as the base cushion layer or layers, an 
adhesion promoter appropriate for a fluoroelastomer layer is applied to 
the metal element, the fluoroelastomer base cushion layer is applied to 
the base cushion primer layer and cured. If the base cushion layer is a 
fluoroelastomer material it is not necessary to cure, prime or to corona 
discharge treat the base cushion fluoroelastomer layer before application 
of the fluoroelastomer layer to it. 
There are optional sandblasting, grinding and polishing steps. As stated 
earlier, it is not necessary to sandblast the metal element, because it is 
not required for good adhesion between the metal element and the adjacent 
layer. However, the fluoroelastomer layer and additional base cushion 
layer or layers, if any, may be ground during the process of making the 
fuser members. These layers may be mechanically ground to provide a smooth 
coating of uniform thickness which sometimes may not be the result when 
these layers are applied to the support, especially by the processes of 
compression-molding or blade-coating. 
Any kind of known heating method can be used to cure or sinter the layers 
onto the fuser member, such as convection heating, forced air heating, 
infrared heating, and dielectric heating. 
The fuser members produced in accordance with the present invention are 
useful in electrophotographic copying machines to fuse heat-softenable 
toner to a substrate. This can be accomplished by contacting a receiver, 
such as a sheet of paper, to which toner particles are electrostatically 
attracted in an imagewise fashion, with such a fuser member. Such contact 
is maintained at a temperature and pressure sufficient to fuse the toner 
to the receiver. Because these members are so durable they can be cleaned 
using a blade, pad, roller or brush during use. And, although it may not 
be necessary because of the excellent release properties of the 
fluoropolymer resin powder layer, release oils may be applied to the fuser 
member without any detriment to the fuser member. 
The following examples illustrate the preparation of the fuser members of 
this invention.

EXAMPLE 1 
A coated roller consisting of a aluminum core, a base cushion primer layer 
and a silicone rubber base cushion layer as the support, and a 
fluoroelastomer layer, and an PFA fluoropolymer resin powder top layer was 
prepared. 
A 5.5 mm (0.220 inch) thick aluminum cylindrical core with a 48 mm (1.93 
inch) diameter and 425 mm (16.75 inch) length that was blasted with glass 
beads and cleaned and dried with dichloromethane and wiped with S11 primer 
available from Emerson Cumming. Over the primer layer a red rubber 
silicone, EC5877 available from Emerson Cumming was coated and cured for 
24 hours at room temperature. After curing, the red rubber was 
mechanically ground to 20 mils. The fluoroelastomer coating was prepared 
by compounding 100 parts of VITON A, 3 parts CURE 20, 6 parts CURE 30, 20 
parts THERMAX and 15 parts lead oxide in a two roll mill for about 30 to 
45 minutes until a uniform composite was produced. Approximately 610 grams 
of the fluoroelastomer composite were prepared. The fluoroelastomer 
material was diluted to a 25% solid solution in a 1:1 methyl ethyl ketone 
and methyl isobutyl ketone solvent and ring-coated onto the EC5877. The 
roller was air dried for 16 hours and post-cured for 24 hours ramp to 
232.degree. C. and 24 hours at 232.degree. C. The fluoroelastomer layer 
had a thickness of 1 mil. The fluoropolymer resin powder DYKOR 810 fine 
PFA available from Whitford was electrostatically spray coated onto the 
fluoroelastomer layer, and then the fuser member was cured for 10 minutes 
at 400.degree. C. in a convection oven. 
The roller had excellent adhesion between the layers. The roller was 
tested. The surface energy of the roller was determined by contact angle 
measurements using a Rame-Hart Inc., NRL model A-100 contact angle 
Goniometer. The low surface energy indicates that the PFA powder coating 
is present on the surface of the Viton A. Wear properties were measured 
using a Norman Abrader test device that ran a strip of paper against a 
fuser roller material to simulate the wearing of a fuser roller in an 
electrostatographic machine. Testing was performed for 1600 cycles at 
175.degree. C. Surface Roughness (Ra) was measured by using a Federal 
Surface Analyzer having a sapphire chisel stylus. 
A life test of the roller was performed by putting the roller into an EK-95 
electrophotographic machine available from Eastman Kodak Co.. The roller 
was used as a fuser roller against the pressure roller in the EK-95 
machine to produce 145,000 copies using 20 lb paper in the duplex mode. 
The test was stopped without any failure or delamination of the roller. 
The results of these tests are in Table 1. 
TABLE 1 
______________________________________ 
Results for Example 1 
______________________________________ 
Surface Enerby 19.87 dyne/cm.sup.2 
Wear 1.3 mil 
Surface Roughness 1.6 micons (64 .mu.in.) 
Life Test 145,000+ copies 
______________________________________ 
Comparative Example 1 
A coated roller consisting of, in order, a support, a fluoroelastomer 
layer, a polyamide-imide-PTFE mixture primer layer and a blend of PTFE and 
PFA fluoropolymer resin layer was prepared. 
A 0.220 inch aluminum cylindrical core with a 80.5 mm (3.17 inch) diameter 
and 422 mm (16.6 inch) length that was blasted with glass beads and 
cleaned and dried with dichloromethane was uniformly spray-coated with an 
adhesion promoter to a uniform thickness of from 0.5 to 1 mil. The 
adhesion promoter consisted of 1 gram of THIXON 300, 1 gram of THIXON 311 
and 2 grams of a mixture of 0.5 grams triphenylamine in 40 grams of methyl 
ethyl ketone. The adhesion promoter was air dried for 15 minutes and 
placed in a convection oven at 176.degree. C. (350.degree. F.) for 10 
minutes. The fluoroelastomer coating was prepared by compounding 100 parts 
of VITON A, 3 parts CURE 20, 6 parts CURE 30, 20 parts THERMAX and 15 
parts lead oxide in a two roll mill for about 30 to 45 minutes until a 
uniform composite was produced. Approximately 610 grams of the 
fluoroelastomer composite were compression molded onto the adhesion 
promoter layer on the core and cured at 325.degree. F. for 2 hours under 
75 tons/in.sup.2 pressure. The mold was opened and closed a few times 
initially to squeeze entrapped air out of the fluoroelastomer material. 
The roller was removed from the mold, and placed in a convection oven for 
post-curing. The conditions for the post-cure were a 24 hour ramp to 
232.degree. C. and 24 hours at 232.degree. C. The fluoroelastomer layer 
was ground to 40 mils in thickness. A uniform layer of primer about 0.3 
mils thick was spray-coated onto the fluoroelastomer layer. The primer was 
SILVERSTONE 855-021 from DuPont. The primer consisted of an aqueous 
dispersion of polyamic acid and PTFE. The primer was air dried. A layer of 
SUPRA SILVERSTONE 855-500, a blend of PTFE and PFA fluoropolymer resins in 
an aqueous dispersion, was spray-coated onto the primer layer to about 1.0 
mil thickness. The fuser member was then placed in a convection oven at 
371.degree. C. (700.degree. F.) for approximately 10 minutes to sinter the 
SUPRA SILVERSTONE. 
The roller of Comparative Example 1 had excellent adhesion between the 
layers; however, a primer was present between the fluoroelastomer layer 
and the fluoropolymer resin layer. The two steps of applying the primer 
and drying the primer described in Comparative Example 1 are steps which 
are not present in the method of this invention. The absence of these 
steps provides for simplified manufacturing of the fuser members of this 
invention. 
The invention has been described in detail with particular reference to 
preferred embodiments thereof, but it will be understood that variations 
and modifications can be effected within the spirit and scope of the 
invention.