Electrically conductive processes

A process for preparing coatings or layers containing a fluorinated carbon filled fluoroelastomer wherein the resistivity of the fluorinated carbon filled fluoroelastomer is controlled.

CROSS REFERENCE TO RELATED APPLICATIONS 
Attention is directed to the following copending applications assigned to 
the assignee of the present application: U.S. application Ser. No. 
08/672,803 filed Jun. 24, 1996, entitled, "Biasable Charging Members;" 
U.S. application Ser. No. 08/635,356 filed Apr. 16, 1996, entitled, 
"Biasable Transfer Members;" Attorney Docket No. D/95610, U.S. application 
Ser. No. 08/786,614 filed Jan. 21, 1997, entitled, "Ohmic 
Contact-Providing Compositions;" U.S. application Ser. No. 08/706,057 
filed Aug. 28, 1996, entitled, "Fixing Apparatus and Film;" U.S. 
application Ser. No. 08/706,387 filed Aug. 28, 1996, entitled, "Instant On 
Fuser System Members;" Attorney Docket No. D/95632, U.S. application Ser. 
No. 08/779,287 filed Jan. 21, 1997, entitled, "Intermediate Transfer 
Members;" and Attorney Docket No. D/96605, U.S. application Ser. No. 
08,808,775 filed Mar. 03, 1997, entitled, "Electrically Conductive 
Coatings." The disclosures of each of these applications are hereby 
incorporated by reference in their entirety. 
BACKGROUND OF THE INVENTION 
The present invention relates to electrically conductive coatings and 
processes for the preparation thereof, and more specifically, to processes 
for producing electrically conductive coatings useful as coatings or 
layers for components for electrical applications, especially 
electrostatographic applications such as xerographic applications. In 
embodiments of the present invention, there are selected electrically 
conductive coatings or layers comprising a polymer filled with an 
electrically conductive material. In a preferred embodiment, the polymer 
is a fluoropolymer, and particularly preferred a fluoroelastomer, and the 
preferred filler is a fluorinated carbon. In embodiments, the present 
invention allows for the preparation and manufacture of coatings or layers 
for xerographic components, the coatings and layers having excellent 
electrical, chemical and mechanical properties, including controlled 
resistivity in a desired resistivity range. Further, in embodiments, the 
coatings and layers exhibit excellent chemical and electrical properties 
such as statistical insensitivity of resistivity to increases in 
temperature and to environmental changes. 
In a typical electrostatographic reproducing apparatus, a light image of an 
original to be copied is recorded in the form of an electrostatic latent 
image upon a photosensitive member and the latent image is subsequently 
rendered visible by the application of electroscopic thermoplastic resin 
particles which are commonly referred to as toner. Generally, the 
electrostatic latent image is developed by bringing a developer mixture 
into contact therewith. A dry developer mixture usually comprises carrier 
granules having toner particles adhering triboelectrically thereto. Toner 
particles are attracted from the carrier granules to the latent image 
forming a toner powder image thereon. Alternatively, a liquid developer 
material may be employed. The liquid developer material includes a liquid 
carrier having toner particles dispersed therein. The liquid developer 
material is advanced into contact with the electrostatic latent image and 
the toner particles are deposited thereon in image configuration. After 
the toner particles have been deposited on the photoconductive surface, in 
image configuration, it is transferred to a substrate such as a copy 
sheet. The toner image is usually fixed or fused upon a support which may 
be the photosensitive member itself or other support sheet such as plain 
paper. 
Because there is required numerous transfers and fixation of charged toner 
particles by various components in the xerographic process, it is desired 
to provide components with layers that allow for the charged particles to 
be exchanged from component to component or from component to substrate 
(in the case of fusing toner to a substrate such as paper) with near 100% 
transfer efficiency. In order to help decrease charge exchange and 
increase toner transfer efficiency, the resistivity of the components must 
be within a desired range, and preferably, the resistivity should be 
virtually unaffected to changes in humidity, temperature and operating 
time. Attempts at controlling the resistivity of various components have 
been accomplished by, for example, adding conductive fillers such as ionic 
additives and/or carbon black to the component layers. 
U.S. Pat. No. 5,537,195 discloses an intermediate transfer member for use 
with liquid developers, wherein the intermediate transfer member comprises 
a fluorocarbon elastomer with metal oxide fillers therein. 
U.S. Pat. No. 5,525,446 discloses an intermediate transfer member for use 
with color systems which includes a base layer and a top polycarbonate 
layer, wherein the top layer can include electrical property regulating 
materials such as metal oxides or carbon black. 
U.S. Pat. No. 5,456,987 discloses an intermediate transfer component for 
both dry and liquid toner, comprising a substrate and a coating comprised 
of integral, interpenetrating networks of haloelastomer, titanium oxide 
and optionally polyorganosiloxane, wherein the substrate may include 
dielectric or conductive fillers such as carbon or metal oxide particles. 
U.S. Pat. No. 5,084,738 discloses use of a resistive heating layer with 
resistivity ranging from 20 to 2000 ohm-cm in a fusing apparatus. The 
resistivity of the layer is achieved by adding conductive carbon fillers 
into a polymer layer. 
U.S. Pat. No. 5,112,708 to Okunuki et al. discloses a charging member 
comprising a surface layer formed of N-alkoxymethylated nylon which may be 
filled with fluorinated carbon. 
While addition of electrically conductive additives to polymers may 
partially control the resistivity of polymer coatings or layers to some 
extent, there are problems associated with the use of these additives, 
such as problems with non-uniform dispersity. In particular, undissolved 
particles frequently bloom or migrate to the surface of the polymer and 
cause an imperfection in the polymer. This leads to a nonuniform 
resistivity, which in turn, leads to poor antistatic properties and poor 
mechanical strength. The ionic additives on the surface may interfere with 
toner release and affect toner offset. Furthermore, bubbles appear in the 
conductive polymer, some of which can only be seen with the aid of a 
microscope, others of which are large enough to be observed with the naked 
eye. These bubbles provide the same kind of difficulty as the undissolved 
particles in the polymer namely, poor or nonuniform electrical properties 
and poor mechanical properties. 
In addition, the ionic additives themselves are sensitive to changes in 
temperature, humidity, and operating time. For the vast majority of 
conductive particle filled systems, there is observed a percolation 
threshold or concentration range in which the resistivity of the filled 
polymer will change by many orders of magnitude over a small 
concentration. These sensitivities often limit the resistivity range. For 
example, the resistivity usually decreases by up to two orders of 
magnitude or more as the humidity increases from 20% to 80% relative 
humidity. This effect limits the operational or process latitude. 
Moreover, ion transfer can also occur in these systems. The transfer of 
ions will lead to charge exchanges and insufficient transfers, which in 
turn, will cause low image resolution and image deterioration, thereby 
adversely affecting the copy quality. In color systems, additional adverse 
results are color shifting and color deterioration. Ion transfer also 
increases the resistivity of the polymer coating or layer after repetitive 
use. This can limit the process and operational latitude and eventually 
the ion-filled polymer component will be unusable. 
Carbon black particles can impart other specific adverse effects. Such 
carbon dispersions are difficult to prepare due to carbon gelling, and the 
resulting layers may deform due to gelatin formation. This can lead to an 
adverse change in the conformability of the layer, which in turn, can lead 
to insufficient transfer and poor copy quality, and possible contamination 
of other machine parts and later copies. 
Generally, carbon additives tend to control the resistivities and provide 
somewhat stable resistivities upon changes in temperature, relative 
humidity, running time, and leaching out of contamination to 
photoconductors. However, the required tolerance in the filler loading to 
achieve the required range of resistivity has been extremely narrow. This, 
along with the large "batch to batch" variation, leads to the need for 
extremely tight resistivity control. In addition, carbon filled polymer 
surfaces have typically had very poor dielectric strength and sometimes 
significant resistivity dependence on applied fields. This leads to a 
compromise in the choice of centerline resistivity due to the variability 
in the electrical properties, which in turn, ultimately leads to a 
compromise in performance. 
Therefore, there exists an overall need for compositions useful as coatings 
or layers for xerographic components and processes for producing such 
coatings or layer, which provide for increased toner transfer efficiency 
and a decrease in the occurrence of charge exchange or toner offset. More 
specifically, there exists a specific need for a composition useful as 
coatings or layers for xerographic components, wherein the layers having 
controlled resistivity in a desired range so as to neutralize toner 
charges, thereby decreasing the occurrence of charge exchange or toner 
offset, increasing image quality and preventing contamination of other 
xerographic members. 
SUMMARY OF THE INVENTION 
Examples of objects of the present invention include: 
It is an object of the present invention to provide processes for producing 
compositions useful as coatings and layers, and methods thereof with many 
of the advantages indicated herein. 
Further, it is an object of the present invention to provide a process for 
producing a coating which has superior electrical properties including a 
stable resistivity in the desired resistivity range. 
It is another object of the present invention to provide a process for 
producing a coating with a controlled resistivity which is virtually 
unaffected by changes in humidity. 
Yet another object of the present invention is to provide a process for 
producing a coating with a controlled resistivity which is virtually 
unaffected by changes in temperature. 
Another object of the present invention is to provide a process for 
producing a coating with a controlled resistivity which is virtually 
unaffected by changes in applied electric field. 
A further object of the present invention is to provide a process for 
producing a coating which possesses a decreased hysteresis effect. A still 
further object of the present invention is to provide a process for 
producing a coating which provides more uniform dispersity of conductive 
filler within the coating. 
The present invention includes, in embodiments: a process for producing a 
fluorinated carbon filled fluoroelastomer coating comprising: a) mixing a 
fluorinated carbon with a fluoroelastomer; b) mixing a curative therewith 
to form a dispersion; c) depositing the dispersion onto a substrate to 
form a layer; and d) curing the deposited layer to form a fluorinated 
carbon filled fluoroelastomer coating. 
Embodiments further include: a process for controlling the resistivity of a 
coating comprising: a) mixing a fluorinated carbon with a fluoroelastomer; 
b) mixing a curative therewith to form a dispersion; c) depositing the 
dispersion onto a substrate to form a layer; and d) curing the deposited 
layer to form a fluorinated carbon filled fluoroelastomer coating, wherein 
the fluorinated carbon filled fluoroelastomer coating has a controlled 
resistivity of from about 10.sup.2 to about 10.sup.14 ohm-cm. 
In addition, embodiments include: a process for the preparation of a 
component comprised of a substrate and a fluorinated carbon filled 
fluoroelastomer coating, wherein the process comprises: a) mixing a 
fluorinated carbon with a fluoroelastomer; b) mixing a curative therewith 
to form a dispersion; c) depositing the dispersion onto a substrate to 
form a layer; and d) curing the deposited layer to form a fluorinated 
carbon filled fluoroelastomer coating, wherein the fluorinated carbon 
filled fluoroelastomer coating has a controlled resistivity of from about 
10.sup.2 to about 10.sup.14 ohm-cm. 
The processes for producing the coatings and layers herein, in embodiments, 
enable control of desired resistivities, allow for uniform electrical 
properties including resistivity, and neutralize toner charges, all of 
which contribute to good release properties, a decrease in the occurrence 
of charge exchange, a decrease in the occurrence of toner offset, an 
increase in image quality, and a decrease in contamination of other 
xerographic components such as photoconductors. The coatings and layers 
provided herein, in embodiments, also have improved insensitivities to 
environmental and mechanical changes. 
DETAILED DESCRIPTION OF THE PRESENT INVENTION 
The present invention relates to processes for producing coatings and 
layers comprising a fluorinated carbon filled fluoroelastomer. These 
coatings and layers are useful as layers for components useful in 
electrical applications, such as xerographic applications. The resistivity 
of the layers or coatings is essential for proper and efficient 
performance of the components. Depending on the function of the component 
and process speed of the apparatus, the electrical requirements for the 
coatings are different. Generally, the desired volume resistivity of the 
coatings is from about 10.sup.2 to about 10.sup.14 ohm-cm, and the desired 
surface resistivity is from about 10.sup.2 to about 10.sup.14 ohm/sq, for 
many xerographic components. The preferred volume resistivity for most 
xerographic systems is from about 10.sup.3 to about 10.sup.12 ohm-cm and 
the pr eferred surface resistivity is from about 10.sup.3 to about 
10.sup.12 ohm/sq. Examples of preferred resistivity ranges for various 
components are as follows. For example, the preferred resistivity range 
for an intermediate transfer belt surface is from about 10.sup.4 to about 
10.sup.12 ohm-cm; the desired volume resistivity for a scavengeless 
development electrode donor member overcoat is about 10.sup.9 ohm-cm; the 
conductive core for a bias charging roll has a desired volume resistivity 
of from about 10.sup.3 to about 10.sup.12 ohm-cm; the preferred 
resistivity of a donor roll coating is from about 10.sup.6 to about 
10.sup.12; while the preferred resistivity of an overcoat for a bias 
charging member is from about 10.sup.3 to about 10.sup.10 ohm-cm. 
A fluoroelastomer in combination with a fluorinated carbon filler dispersed 
therein, provides superior results by, for example, allowing a resistivity 
within a specific range desired for a specific application, wherein the 
resistivity is virtually unaffected by environmental changes such as 
changes in humidity and temperature, or mechanical changes such as changes 
in the electrical charge or field associated with the component. This 
controlled resistivity is an important and superior feature of the present 
invention. 
More specifically, although with known coatings, a change in temperature or 
a change in humidity can cause a severe change in the resistivity of the 
coating, the coatings of the present invention are much less reactive to 
environmental changes. The coatings comprising fluorinated carbon filled 
fluoroelastomers have controlled resistivity. For example, the resistivity 
usually decreases by up to two orders of magnitude or more as the humidity 
increases from 20% to 80% relative humidity. This effect limits the 
operational or process latitude. However, with fluorinated carbon filled 
fluoroelastomers, the resistivity of the coating is controlled and will 
remain within the desired range of 10.sup.2 to about 10.sup.14 ohms-cm, or 
the preferred range of from about 10.sup.3 to about 10.sup.14 ohms-cm, at 
broad temperatures ranging from about 0.degree. C. to about 200.degree. 
C., and/or at broad humidity ranges of 0 to about 80% relative humidity. 
In preferred embodiments, the desired resistivity will remain within from 
about 50 to about 100% of the original desired resistivity range upon a 
temperature range of from about 0.degree. C. to about 200.degree. C., 
and/or will remain within from about 50 to about 100% of the desired 
resistivity range upon a change in relative humidity of from about 0 to 
about 80% relative humidity. The original desired resistivity is the 
desired resistivity which is measured at room temperature, or about 
25.degree. C., and at ambient relative humidity, or about 50% relative 
humidity. This desired resistivity will be a resistivity chosen for a 
particular coating for a specific component. The desired resistivity will 
vary depending on the component and the desired qualities, performance and 
use of the component. In addition to remaining stable upon broad changes 
in temperature and relative humidity, the controlled resistivity is 
virtually unaffected by exposure of the coating to corona affluent. 
Using fluorinated carbon as a filler in fluoroelastomers which are formed 
into coatings or layers for components useful in xerographic applications 
helps to solve the problems related to incomplete toner transfer from 
component to component or hot offset caused by toner from the substrate 
adhering to the fusing surface. The coatings and layers in accordance with 
the present invention, enable high yield transfer of toner particles from 
the various component members due to the combination of fluorinated carbon 
and fluoroelastomer which, in combination, provide for a stable 
resistivity within the desired range. Further, such fluorinated carbon 
filled fluoroelastomers greatly reduce the charge exchange between the 
components, or between the components and a substrate. 
The particular resistivity of the fluoropolymer composition can be chosen 
and controlled depending, for example, on the amount of fluorinated 
carbon, the kind of curative, the nature of the curative, the amount of 
fluorine in the fluorinated carbon, and the curing procedures including 
the specific curing agent such as for example MgO, Mg(OH).sub.2, CaO, 
Ca(OH).sub.2, and the like, curing time, and curing temperature. The 
resistivity can be generated not only by selecting the appropriate curing 
agents, curing time and curing temperature as set forth above, but also by 
selecting a specific polymer and filler, such as a specific fluorinated 
carbon, or mixtures of various types of fluorinated carbon. The percentage 
of fluorine in the fluorinated carbon will also affect the resistivity of 
the fluoroelastomer when mixed therewith. 
Fluorinated carbon, sometimes referred to as graphite fluoride or carbon 
fluoride, is a solid material resulting from the fluorination of carbon 
with elemental fluorine. The number of fluorine atoms per carbon atom may 
vary depending on the fluorination conditions. The variable fluorine atom 
to carbon atom stoichiometry of fluorinated carbon permits systemic, 
uniform variation of its electrical resistivity properties. 
Fluorinated carbon refers to a specific class of compositions which is 
prepared by reacting fluorine to one or more of the many forms of solid 
carbon. In addition, the amount of fluorine can be varied in order to 
produce a specific, desired resistivity. Fluorocarbons are either 
aliphatic or aromatic organic compounds wherein one or more fluorine atoms 
have been attached to one or more carbon atoms to form well defined 
compounds with a single sharp melting point or boiling point. 
Fluoropolymers are linked-up single identical molecules which comprise 
long chains bound together by covalent bonds. Moreover, fluoroelastomers 
are a specific type of fluoropolymer. Thus, despite some apparent 
confusion in the art, it is apparent that fluorinated carbon is neither a 
fluorocarbon nor a fluoropolymer and the term is used in this context 
herein. 
The fluorinated carbon may include the fluorinated carbon materials as 
described herein. The methods for preparation of fluorinated carbon are 
well known and documented in the literature, such as in the following U.S. 
Pat. Nos. 2,786,874; 3,925,492; 3,925,263; 3,872,032 and 4,247,608, the 
disclosures each of which are totally incorporated by reference herein. 
Essentially, fluorinated carbon is produced by heating a carbon source 
such as amorphous carbon, coke, charcoal, carbon black or graphite with 
elemental fluorine at elevated temperatures, such as 
150.degree.-600.degree. C. A diluent such as nitrogen is preferably 
admixed with the fluorine. The nature and properties of the fluorinated 
carbon vary with the particular carbon source, the conditions of reaction 
and with the degree of fluorination obtained in the final product. The 
degree of fluorination in the final product may be varied by changing the 
process reaction conditions, principally temperature and time. Generally, 
the higher the temperature and the longer the time, the higher the 
fluorine content. 
Fluorinated carbon of varying carbon sources and varying fluorine contents 
is commercially available from several sources. Preferred carbon sources 
are carbon black, crystalline graphite and petroleum coke. One form of 
fluorinated carbon which is suitable for use in accordance with the 
invention is polycarbon monofluoride which is usually written in the 
shorthand manner CF.sub.x with x representing the number of fluorine atoms 
and generally being up to about 1.5, preferably from about 0.01 to about 
1.5, and particularly preferred from about 0.04 to about 1.4. The formula 
CF.sub.x has a lamellar structure composed of layers of fused six carbon 
rings with fluorine atoms attached to the carbons and lying above and 
below the plane of the carbon atoms. Preparation of CF.sub.x type 
fluorinated carbon is described, for example, in above-mentioned U.S. Pat. 
Nos. 2,786,874 and 3,925,492, the disclosures of which are incorporated by 
reference herein in their entirety. Generally, formation of this type of 
fluorinated carbon involves reacting elemental carbon with F.sub.2 
catalytically. This type of fluorinated carbon can be obtained 
commercially from many vendors, including Allied Signal, Morristown, N.J.; 
Central Glass International, Inc., White Plains, N.Y.; Diakin Industries, 
Inc., New York, N.Y.; and Advance Research Chemicals, Inc., Catoosa, Okla. 
Another form of fluorinated carbon which is suitable for use in accordance 
with the invention is that which has been postulated by Nobuatsu Watanabe 
as poly(dicarbon monofluoride) which is usually written in the shorthand 
manner (C.sub.2 F).sub.n. The preparation of (C.sub.2 F).sub.n type 
fluorinated carbon is described, for example, in above-mentioned U.S. Pat. 
No. 4,247,608, the disclosure of which is herein incorporated by reference 
in its entirety, and also in Watanabe et al., "Preparation of 
Poly(dicarbon monofluoride) from Petroleum Coke", Bull. Chem. Soc. Japan, 
55, 3197-3199 (1982), the disclosure of which is also incorporated herein 
by reference in its entirety. 
In addition, preferred fluorinated carbons selected include those described 
in U.S. Pat. No. 4,524,119 to Luly et al., the subject matter of which is 
hereby incorporated by reference in its entirety, and those having the 
tradename ACCUFLUOR.RTM., (ACCUFLUOR.RTM. is a registered trademark of 
Allied Signal, Morristown, N.J.) for example, ACCUFLUOR.RTM. 2028, 
ACCUFLUOR.RTM. 2065, ACCUFLUOR.RTM. 1000, and ACCUFLUOR.RTM. 2010. 
ACCUFLUOR.RTM. 2028 and ACCUFLUOR.RTM. 2010 have 28 and 11 percent 
fluorine content, respectively. ACCUFLUOR.RTM. 1000 and ACCUFLUOR.RTM. 
2065 have 62 and 65 percent fluorine content respectively. Also, 
ACCUFLUOR.RTM. 1000 comprises carbon coke, whereas ACCUFLUOR.RTM. 2065, 
2028 and 2010 all comprise conductive carbon black. These fluorinated 
carbons are of the formula CF.sub.x and are formed by the reaction of 
C+F.sub.2 =CF.sub.x. 
The following chart illustrates some properties of four preferred 
fluorinated carbons of the present invention. 
______________________________________ 
PROPERTIES 
ACCUFLUOR .RTM. UNITS 
______________________________________ 
GRADE 1000 2065 2028 2010 N/A 
Feedstock Coke Conductive Carbon Black 
N/A 
Fluorine Content 
62 65 28 11 % 
True Density 
2.7 2.5 2.1 1.9 g/cc 
Bulk Density 
0.6 0.1 0.1 0.09 g/cc 
Decomposition 
630 500 450 380 .degree.C. 
Temperature 
Median Particle 
8 &lt;1 &lt;1 &lt;1 micrometers 
Size 
Surface Area 
130 340 130 170 m.sup.2 /g 
Thermal 10.sup.-3 
10.sup.-3 
10.sup.-3 
N.A. cal/cm-sec-.degree.C. 
Conductivity 
Electrical 
10.sup.11 
10.sup.11 
10.sup.8 
&lt;10 ohm-cm 
Resistivity 
Color Gray White Black Black N/A 
______________________________________ 
As has been described herein, a major advantage of the invention is the 
capability to vary the fluorine content of the fluorinated carbon to 
permit systematic uniform variation of the resistivity properties of the 
composition or layer. The preferred fluorine content will depend on inter 
alia the equipment used, equipment settings, desired resistivity, and the 
specific fluoroelastomer chosen. The fluorine content in the fluorinated 
carbon is from about 1 to about 70 weight percent based on the weight of 
fluorinated carbon (carbon content of from about 99 to about 30 weight 
percent), preferably from about 5 to about 65 (carbon content of from 
about 95 to about 35 weight percent), and particularly preferred from 
about 10 to about 30 weight percent (carbon content of from about 90 to 
about 70 weight percent). 
The median particle size of the fluorinated carbon can be less than 1 
micron and up to 10 microns, is preferably less than 1 micron, preferably 
from about 0.001 to about 1 microns, and particularly preferred from about 
0.5 to 0.9 micron. The surface area is preferably from about 100 to about 
400 m.sup.2 /g, preferred of from about 110 to about 340, and particularly 
preferred from about 130 to about 170 m.sup.2 /g. The density of the 
fluorinated carbons is preferably from about 1.5 to about 3 g/cc, 
preferably from about 1.9 to about 2.7 g/cc. 
The amount of fluorinated carbon in the layer is from about 1 to about 50 
percent by weight of the total solids content, preferably from about 1 to 
about 40 weight percent, and particularly preferred from about 5 to about 
30 weight percent based on the weight of total solids. Total solids as 
used herein refers to the amount of fluoroelastomer and/or other 
elastomers. 
It is preferable to mix different types of fluorinated carbon to tune the 
mechanical and electrical properties. It is desirable to use mixtures of 
different kinds of fluorinated carbon to achieve good resistivity while 
reducing the hardness of the coating. Also, mixtures of different kinds of 
fluorinated carbon can provide an unexpected wide formulation latitude and 
controlled and predictable resistivity. For example, an amount of from 
about 0 to about 40 percent, preferably from about 1 to about 40, and 
particularly preferred of from about 5 to about 35 percent by weight of 
ACCUFLUOR.RTM. 2010 can be mixed with an amount of from about 0 to about 
40 percent, preferably from about 1 to about 40, and particularly 
preferred from about 5 to about 35 percent ACCUFLUOR.RTM. 2028, and even 
more particularly preferred from about 8 to about 25 percent 
ACCUFLUOR.RTM. 2028. Other forms of fluorinated carbon can also be mixed. 
Another example is an amount of from about 0 to about 40 percent 
ACCUFLUOR.RTM. 1000, and preferably from about 1 to about 40 percent, and 
particularly preferred from about 5 to about 35 percent, mixed with an 
amount of from about 0 to about 40 percent, preferably from about 1 to 
about 40, and particularly preferred from about 1 to about 35 percent 
ACCUFLUOR.RTM. 2065. All other combinations of mixing the different forms 
of ACCUFLUOR.RTM. are possible. A preferred mixture is from about 0 to 
about 15 percent ACCUFLUOR.RTM. 2028 mixed with from about 2 to about 3.5 
percent ACCUFLUOR.RTM. 2010. Another preferred mixture is from about 0.5 
to about 10 percent ACCUFLUOR.RTM. 2028 mixed with from about 2.0 to about 
3.0 percent ACCUFLUOR.RTM. 2010. A particularly preferred mixture is from 
about 1 to about 3 percent ACCUFLUOR.RTM. 2028 mixed with from about 2.5 
to about 3 percent ACCUFLUOR.RTM. 2010, and even more preferred is a 
mixture of about 3 percent ACCUFLUOR.RTM. 2010 and about 2 percent 
ACCUFLUOR.RTM. 2028. All the above percentages are by weight of the total 
solids. 
The fluorinated carbon is preferably dispersed in a polymer. Examples of 
suitable polymers include fluoropolymers and particularly, 
fluoroelastomers. Specifically, suitable fluoroelastomers are those 
described in detail in U.S. Pat. Nos. 5,166,031, 5,281,506, 5,366,772 and 
5,370,931, together with U.S. Pat. Nos. 4,257,699, 5,017,432 and 
5,061,965, the disclosures each of which are incorporated by reference 
herein in their entirety. As described therein these fluoroelastomers, 
particularly from the class of copolymers and terpolymers of 
vinylidenefluoride, hexafluoropropylene and tetrafluoroethylene, are known 
commercially under various designations as VITON.RTM. A, VITON.RTM. E, 
VITON.RTM. E60C, VITON.RTM. E430, VITON.RTM. 910, VITON.RTM. GH and 
VITON.RTM. GF. The VlTON.RTM. designation is a Trademark of E.I. DuPont de 
Nemours, Inc. Other commercially available materials include FLUOREL.RTM. 
2170, FLUOREL.RTM. 2174, FLUOREL.RTM. 2176, FLUOREL.RTM. 2177 and 
FLUOREL.RTM. LVS 76. FLUOREL.RTM. is a Trademark of 3M Company. Additional 
commercially available materials include AFLAS.sup.1m a 
poly(propylene-tetrafluoroethylene) and FLUOREL II.RTM. (LII900) a 
poly(propylene-tetrafluoroethylenevinylidenefluoride) both also available 
from 3M Company, as well as the Tecnoflons identified as FOR-60KIR.RTM., 
FOR-LHF.RTM., NM.RTM. FOR-THF.RTM., FOR-TFS.RTM., TH.RTM., TN505.RTM. 
available from Montedison Specialty Chemical Company. In another preferred 
embodiment, the fluoroelastomer is one having a relatively low quantity of 
vinylidenefluoride, such as in VITON.RTM. GF, available from E.I. DuPont 
de Nemours, Inc. The VITON.RTM. GF has 35 mole percent of 
vinylidenefluoride, 34 mole percent of hexafluoropropylene and 29 mole 
percent of tetrafluoroethylene with 2 percent cure site monomer. The cure 
site monomer can be 4-bromoperfluorobutene-1, 
1,1-dihydro-4-bromoperfluorobutene-1, 3-bromoperfluoropropene-1, 
1,1-dihydro-3-bromoperfluoropropene-1, available from DuPont, or any other 
suitable, known cure site monomer. 
Examples of fluoroelastomers suitable for use herein include elastomers of 
the above type, along with volume grafted elastomers. Volume grafted 
elastomers are a special form of hydrofluoroelastomer and are 
substantially uniform integral interpenetrating networks of a hybrid 
composition of a fluoroelastomer and a polyorganosiloxane, the volume 
graft having been formed by dehydrofluorination of fluoroelastomer by a 
nucleophilic dehydrofluorinating agent, followed by addition 
polymerization by the addition of an alkene or alkyne functionally 
terminated polyorganosiloxane and a polymerization initiator. Examples of 
specific volume graft elastomers are disclosed in U.S. Pat. No. 5,166,031; 
U.S. Pat. No. 5,281,506; U.S. Pat. No. 5,366,772; and U.S. Pat. No. 
5,370,931, the disclosures each of which are herein incorporated by 
reference in their entirety. 
Volume graft, in embodiments, refers to a substantially uniform integral 
interpenetrating network of a hybrid composition, wherein both the 
structure and the composition of the fluoroelastomer and 
polyorganosiloxane are substantially uniform when taken through different 
slices of the layers of the member. A volume grafted elastomer is a hybrid 
composition of fluoroelastomer and polyorganosiloxane formed by 
dehydrofluorination of fluoroelastomer by nucleophilic dehydrofluorinating 
agent followed by addition polymerization by the addition of alkene or 
alkyne functionally terminated polyorganosiloxane. 
Interpenetrating network, in embodiments, refers to the addition 
polymerization matrix where the fluoroelastomer and polyorganosiloxane 
polymer strands are intertwined in one another. 
Hybrid composition, in embodiments, refers to a volume grafted composition 
which is comprised of fluoroelastomer and polyorganosiloxane blocks 
randomly arranged. 
Generally, the volume grafting according to the present invention is 
performed in two steps, the first involves the dehydrofluorination of the 
fluoroelastomer preferably using an amine. During this step, hydrofluoric 
acid is eliminated which generates unsaturation, carbon to carbon double 
bonds, on the fluoroelastomer. The second step is the free radical 
peroxide induced addition polymerization of the alkene or alkyne 
terminated polyorganosiloxane with the carbon to carbon double bonds of 
the fluoroelastomer. In embodiments, copper oxide can be added to a 
solution containing the graft copolymer. The dispersion is then provided 
onto the substrate or conductive film surface. 
In embodiments, the polyorganosiloxane having functionality according to 
the present invention has the formula: 
##STR1## 
where R is an alkyl from about 1 to about 24 carbons, or an alkenyl of 
from about 2 to about 24 carbons, or a substituted or unsubstituted aryl 
of from about 4 to about 18 carbons; A is an aryl of from about 6 to about 
24 carbons, a substituted or unsubstituted alkene of from about 2 to about 
8 carbons, or a substituted or unsubstituted alkyne of from about 2 to 
about 8 carbons; and n represents the number of segments and is, for 
example, from about 2 to about 400, and preferably from about 10 to about 
200 in embodiments. 
In preferred embodiments, R is an alkyl, alkenyl or aryl, wherein alkyl 
contains from about 1 to about 24 carbons, preferably from about 1 to 
about 12 carbons; alkenyl contains from about 2 to about 24 carbons, 
preferably from about 2 to about 12 carbons; and aryl contains from about 
6 to about 24 carbon atoms, preferably from about 6 to about 18 carbons. R 
may be a substituted aryl group, wherein the aryl may be substituted with 
an amino, hydroxy, mercapto or substituted with an alkyl having for 
example from about 1 to about 24 carbons and preferably from 1 to about 12 
carbons, or substituted with an alkenyl having for example from about 2 to 
about 24 carbons and preferably from about 2 to about 12 carbons. In a 
preferred embodiment, R is independently selected from methyl, ethyl, and 
phenyl. The functional group A can be an alkene or alkyne group having 
from about 2 to about 8 carbon atoms, preferably from about 2 to about 4 
carbons, optionally substituted with an alkyl having for example from 
about 1 to about 12 carbons, and preferably from about 1 to about 12 
carbons, or an aryl group having for example from about 6 to about 24 
carbons, and preferably from about 6 to about 18 carbons. Functional group 
A can also be mono-, di-, or trialkoxysilane having from about 1 to about 
10 and preferably from about 1 to about 6 carbons in each alkoxy group, 
hydroxy, or halogen. Preferred alkoxy groups include methoxy, ethoxy, and 
the like. Preferred halogens include chlorine, bromine and fluorine. Group 
A may also be an alkyne of from about 2 to about 8 carbons, optionally 
substituted with an alkyl of from about 1 to about 24 carbons or aryl of 
from about 6 to about 24 carbons. The group n is a number of from about 2 
to about 400, and in embodiments from about 2 to about 350, and preferably 
from about 5 to about 100. Furthermore, in a preferred embodiment n is 
from about 60 to about 80, to provide a sufficient number of reactive 
groups to graft onto the fluoroelastomer. In the above formula, typical R 
groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, 
vinyl, allylic crotnyl, phenyl, naphthyl and phenanthryl, and typical 
substituted aryl groups are substituted in the ortho, meta and para 
positions with lower alkyl groups having from about 1 to about 15 carbon 
atoms. Typical alkene and alkenyl functional groups include vinyl, 
acrylic, crotonic and acetenyl which may typically be substituted with 
methyl, propyl, butyl, benzyl, tolyl groups, and the like. 
In a preferred embodiment of the present invention, the polymer coating or 
layer is comprised of a fluorinated carbon filled fluoroelastomer, wherein 
the fluoroelastomer is VITON.RTM. GF and the fluorinated carbon is 
selected from ACCUFLUOR.RTM. 1000, ACCUFLUOR.RTM. 2065, ACCUFLUOR.RTM. 
2028, ACCUFLUOR.RTM. 2010, or mixtures thereof. 
The amount of fluoroelastomer used to provide the coatings or layers of the 
present invention is dependent on the amount necessary to form the desired 
thickness of the coatings or layers. Specifically, the fluoroelastomer is 
added in an amount of from about 60 to about 99 percent, preferably about 
70 to about 99 percent by weight of total solids. 
Any known solvent suitable for dissolving a fluoroelastomer may be used in 
the present invention. Examples of suitable solvents for the present 
invention include methyl ethyl ketone, methyl isobutyl ketone, diethyl 
ketone, cyclohexanone, n-butyl acetate, amyl acetate, and the like. 
Specifically, the solvent is added in an amount of from about 25 to about 
99 percent, preferably from about 70 to about 95 percent. 
The curative package can be important in promoting controlled conductivity, 
and includes crosslinkers, accelerators and metal compounds such as metal 
oxides or metal hydroxides. The dehydrofluorinating agent which attacks 
the fluoroelastomer generating unsaturation is selected from basic metal 
oxides such as MgO, Mg(OH).sub.2, CaO, Ca(OH).sub.2 and the like, and 
strong nucleophilic agents such as primary, secondary and tertiary, 
aliphatic and aromatic amines, where the aliphatic and aromatic amines 
have from about 2 to about 30 carbon atoms. Also included are aliphatic 
and aromatic diamines and triamines having from about 2 to about 30 carbon 
atoms where the aromatic groups may be benzene, toluene, naphthalene, 
anthracene, and the like. It is generally preferred for the aromatic 
diamines and triamines that the aromatic group be substituted in the 
ortho, meta and para positions. Typical substituents include lower alkyl 
amino groups such as ethylamino, propylamino and butylamino, with 
propylamino being preferred. The particularly preferred curing agents are 
the nucleophilic curing agents such as VITON CURATIVE VC-50.RTM. which 
incorporates an accelerator (such as a quaternary phosphonium salt or 
salts like VC-20) and a crosslinking agent (bisphenol AF or VC-30); DIAK 1 
(hexamethylenediamine carbamate) and DIAK 3 which also has a dual function 
and acts as an accelerator and a crosslinker (N,N'-dicinnamylidene-1,6 
hexanediamine). The dehydrofluorinating agent or curing agent is added in 
an amount of from about 1 to about 20 weight percent, preferably from 
about 2 to about 10 weight percent, and particularly preferred from about 
1.5 to about 5 weight percent. It has been demonstrated that the curative 
is important to providing resistivity in the coating. Specifically, in the 
absence of a curative, controlled resistivity is not attained. 
Layers or coatings may be formed by forming a coating dispersion by mixing 
together the fluorinated carbon, fluoroelastomer, solvent and curative 
materials, and coating the resulting conductive coating dispersion on a 
substrate. 
The coatings or layers may be deposited on a substrate via a well known 
coating processes. Known methods for forming coatings or layer(s) on a 
substrate include dipping, spraying such as by multiple spray applications 
of very thin films, casting, flow-coating, web-coating, roll-coating, 
extrusion, molding, or the like. It is preferred to deposit the layers by 
spraying such as by multiple spray applications of very thin films, by web 
coating or by flow-coating. More than one coating dispersion of 
fluorinated carbon filled fluoroelastomer can be coated on a substrate. 
Multiple layers or coatings can be applied to the substrate. For example, 
from 1 to about 5 layers or coatings can be applied to the substrate. 
The coatings or layers deposited on a substrate are then dried and cured 
according to known curing procedures, including step heat curing. A lower 
resistivity is obtained when the coatings or layers are cured at a higher 
temperature or over a longer period of time. In other words, resistivity 
has been shown to decrease upon an increase in curing temperature. 
Similarly, resistivity has been shown to decrease upon an increase in 
curing time. 
Preferably, the curing time is from about 1 to about 20 hours, preferably 
about 16 hours and the curing temperature is from about 25.degree. to 
about 250.degree. C., preferably from about 120.degree. to about 
250.degree. C., and particularly preferred from about 160.degree. to about 
235.degree. C. It has been demonstrated that post-treatment steps 
including heat-curing step and other current treatments, is important to 
the achievement of controlled resistivity. Specifically, in the absence of 
heat curing, controlled resistivity is not attained. Therefore, both a 
curing agent and a heat curing step are important features in providing 
controlled resistivity in the fluorinated carbon filled fluoroelastomers. 
Current treatments have also been shown to induce electrical conductivity 
and controlled conductivity. The deposited fluorinated carbon filled 
fluoroelastomer is subjected to current treatment sufficient to induce 
conductivity, for example, at a current of from about 1 to about 20 
miliamps, and preferably, from about 5 to about 15 miliamps. The layer is 
subjected to the current treatment for a time sufficient to induce 
electrical conductivity, for example from about 5 to about 200 minutes, 
and preferably from about 10 to about 150 minutes. 
The mechanism is theorized as follows. It is believed that the starting 
fluorinated carbon undergoes a defluorination reaction with the 
fluoroelastomer curative during the fluoroelastomer curing. This results 
in a fluorinated carbon of lesser fluorine content in the binder. It is 
believed that this is the filler that leads to controlled resistivity. It 
is also possible that during defluorination, the fluorinated carbon may 
crosslink with the fluoroelastomer, thereby providing a more stable 
composition. 
The coatings and layers, as used herein, can be any layer of any suitable 
electrical or mechanical component useful in xerographic or other 
electrical processes or apparatuses. The layer can be any one intermediate 
layer(s), or an outer coating layer of a component. Examples of such 
xerographic components include intermediate transfer members, bias 
charging members, bias transfer members, segmented electrode development 
members, fuser members, donor roll members, image bearing members, or any 
other related components. 
The polymer coatings and layers comprising a fluorinated carbon filled 
fluoroelastomer exhibit superior electrical and mechanical properties. The 
coatings and layers are designed so as to enable control of electrical 
properties including control of resistivity in the desired resistivity 
range, wherein the resistivity is virtually insensitive to environmental 
and mechanical changes. 
All the patents and applications referred to herein are hereby 
specifically, and totally incorporated herein by reference in their 
entirety in the instant specification. 
The following Examples further define and describe embodiments of the 
present invention. Unless otherwise indicated, all parts and percentages 
are by weight.

EXAMPLES 
Example I 
A coating dispersion consisting of ACCUFLUOR.RTM. 2028 (from Allied Signal) 
and VITON.RTM. GF (from DuPont) in a weight ratio of 1:3 was prepared in 
the following manner. About 2,300 g of steel shot and 15 g of 
ACCUFLUOR.RTM. 2028 were added to a small bench top attritor (Model 1A), 
which contained 200 g of methyl ethyl ketone (MEK) (from Fisher). The 
mixture was gently stirred for about a minute so that the fluorinated 
carbon particles became wet due to the solvent. VITON.RTM. GF (45 g) was 
then added and the resulting mixture attrited for 30 minutes. A curative 
package 2.25 g VC-50 (from DuPont), 0.9 g Maglite-D (from Baker) and 0.2 
g (Ca(OH).sub.2) (from Baker)! and 10 g of a stabilizing solvent, 
methanol, were introduced and the resulting mixture was then further mixed 
on the attritor for another 15 minutes. After filtering the steel shot 
through a wire screen, the dispersion was collected in an 8-oz 
polypropylene bottle. The resulting dispersion was then coated onto 
polyimide KAPTON.RTM. substrates (from DuPont) and on stainless steel 
substrates within 2-5 hours using a Gardner Laboratory Coater. The coated 
layers were air-dried for about 1-2 hours, and then step heat-cured in a 
programmable oven. The heating sequence was as follows: (1) 65.degree. C. 
for 4 hours, (2) 93.degree. C. for 2 hours, (3) 144.degree. C. for 2 
hours, (4) 177.degree. C. for 2 hours, (5) 204.degree. C. for 2 hours and 
(6) 232.degree. C. for 16 hours. The layers were about 2.5 to about 3 mil 
in thickness and were post-cured at 235.degree. C. for 16 hours. The 
layers that resulted were VITON.RTM. GF layers containing 25% by weight 
ACCUFLUOR.RTM. 2028. 
The surface resistivity of the cured VITON.RTM. GF layers was measured by a 
Xerox Corporation in-house testing apparatus with a power supply (Trek 
601C Coratrol), a Keithy electrometer (model 610B), and a two point 
conformable guarded electrode probe (15 mm spacing between the two 
electrodes). The field applied for the measurement was 500 V/cm and the 
measured current was converted to surface resistivity based on the 
geometry of the probe. The surface resistivity of the layer was determined 
to be approximately 1.times.10.sup.10 ohm/sq. 
The volume resistivity of the layer was determined by the standard AC 
conductivity technique. The surface of the VITON.RTM. GF was coated 
directly onto a stainless steel substrate, in the absence of an 
intermediate layer. An evaporated aluminum thin film (300 .ANG.) was used 
as the counter electrode. The volume resistivity was found to be 
6.times.10.sup.11 ohm-cm at an electric field of 1500 V/cm. The 
resistivity was found to be insensitive to changes in temperature in the 
range of about 20.degree. C. to about 150.degree. C., and to changes in 
relative humidity in the range of about 20% to about 80%, and to the 
intensity of applied electric field (up to 2,000 V/cm). Furthermore, no 
hysteresis (memory) effect was seen after the layer was cycled to higher 
electric fields (&gt;10.sup.4 V/cm). 
Example II 
The procedures outlined in Example 1 were repeated except that the loadings 
of the fluorinated carbon filler ACCUFLUOR.RTM. 2028 were varied and 
ACCUFLUOR.RTM. 2010 was also tested. These layers were found to exhibit 
very similar electric properties as the layers in Example 1. The results 
are shown below in Table 1. 
TABLE 1 
______________________________________ 
RESISTIVITY DATA OF FLUORINATED CARBON 
IN VITON .RTM. GF (FIELD .about.1500 V/CM) 
Surface Volume 
Fluorinated Loading Resistivity 
Resistivity 
Carbon (% by weight) 
(ohm/sq) (ohm-cm) 
______________________________________ 
ACCUFLUOR .RTM. 2028 
35 1.7 .times. 10.sup.7 
.about.1.6 .times. 10.sup.8 
ACCUFLUOR .RTM. 2028 
30 1.0 .times. 10.sup.9 
.about.1 .times. 10.sup.9 
ACCUFLUOR .RTM. 2028 
20 .sup. 8.9 .times. 10.sup.11 
.sup. .about.2 .times. 10.sup.13 
ACCUFLUOR .RTM. 2010 
30 8.3 .times. 10.sup.4 
ACCUFLUOR .RTM. 2010 
10 1.9 .times. 10.sup.5 
ACCUFLUOR .RTM. 2010 
5 4.1 .times. 10.sup.5 
ACCUFLUOR .RTM. 2010 
3.5 4.5 .times. 10.sup.6 
ACCUFLUOR .RTM. 2010 
3 1.7 .times. 10.sup.8 
______________________________________ 
Example III 
A number of resistive layers were prepared using the dispersing and coating 
procedure as described in Example I, with the exception that a mixture of 
various percentages by weight of various types of ACCUFLUOR.RTM. were 
mixed with VITON.RTM. GF. The compositions of the 
ACCUFLUOR.RTM./VITON.RTM. GF layers and the surface resistivity results 
are summarized in Table 2. 
TABLE 2 
______________________________________ 
Fillers in VITON .RTM. GF 
Surface Resistivity 
(%) (ohm/sq) 
______________________________________ 
2% ACCUFLUOR .RTM. 2010 
.sup. 4.5 .times. 10.sup.11 
15% ACCUFLUOR .RTM. 2028 
2.5% ACCUFLUOR .RTM. 2010 
1.0 .times. 10.sup.9 
15% ACCUFLUOR .RTM. 2028 
3% ACCUFLUOR .RTM. 2010 
5.4 .times. 10.sup.9 
5% ACCUFLUOR .RTM. 2028 
3% ACCUFLUOR .RTM. 2010 
6.4 .times. 10.sup.9 
10% ACCUFLUOR .RTM. 2028 
3% ACCUFLUOR .RTM. 2010 
.sup. 1.3 .times. 10.sup.10 
15% ACCUFLUOR .RTM. 2028 
3.5% ACCUFLUOR .RTM. 2010 
2 .times. 10.sup.9 
5% ACCUFLUOR .RTM. 2028 
3.5% ACCUFLUOR .RTM. 2010 
7.2 .times. 10.sup.9 
15% ACCUFLUOR .RTM. 2028 
______________________________________ 
Example IV 
Resistive layers containing of 25% by weight of ACCUFLUOR.RTM. in 
VITON.RTM. GF were prepared according to the procedures described in 
Example I. However, instead of performing a post-curing at 232.degree. C. 
for 16 hours, the post-curing was performed for 9 hours, 26 hours, 50 
hours, 90 hours and 150 hours, respectively. The surface resistivity 
results are shown in Table 3. 
TABLE 3 
______________________________________ 
Surface Resistivity 
Post-curing Time 
(ohm/sq) 
______________________________________ 
9 hours .sup. 5.5 .times. 10.sup.10 
26 hours 8.8 .times. 10.sup.9 
50 hours 1.8 .times. 10.sup.9 
90 hours 7.3 .times. 10.sup.7 
150 hours 7.2 .times. 10.sup.6 
______________________________________ 
Example V 
Coating dispersions containing different concentrations of ACCUFLUOR.RTM. 
2010 in VITON.RTM. GF were prepared using the attrition procedures given 
in Example I. These dispersions were then air-sprayed onto KAPTON.RTM. 
substrates. The layers (.about.2.5 mil) were air-dried and post-cured 
using the procedure outlined in Example I. The surface resistivity results 
are summarized in Table 4 below. The percentages are by weight. 
TABLE 4 
______________________________________ 
ACCUFLUOR .RTM. 2010 
Surface Resistivity 
Loading in VITON .RTM. GF (%) 
(ohm/sq) 
______________________________________ 
6% .sup. 1.6 .times. 10.sup.12 
7% 7.0 .times. 10.sup.8 
8% 8.5 .times. 10.sup.7 
10% 6.2 .times. 10.sup.6 
20% 1.1 .times. 10.sup.5 
______________________________________ 
Example VI 
A resistive layer containing of 30% ACCUFLUOR.RTM. 2028 in VITON.RTM. GF 
was prepared according to the procedures described in Example I, with the 
exception that 4.5 g of curative VC-50 was used. The surface resistivity 
of the layer was measured using the techniques outlined in Example 1 and 
was found to be approximately 5.7.times.10.sup.9 ohm/sq. 
Example VII 
A coating dispersion was prepared by first adding a solvent (200 g of 
methyl ethyl ketone), a steel shot (2,300 g) and 2.4 g of ACCUFLUOR.RTM. 
2028 in a small bench top attritor (model 01A). The mixture was stirred 
for about one minute so as to wet the fluorinated carbon with the solvent. 
A polymer binder, VITON.RTM. GF (45 g), was then added and the resulting 
mixture was attrited for 30 minutes. A curative package (0.68 g DIAK 1 and 
0.2 g Maglite Y) and a stabilizing solvent (10 g methanol) were then 
introduced and the mixture was further mixed for about 15 minutes. After 
filtering the steel shot through a wire screen, the fluorinated 
carbon/VITON.RTM. GF dispersion was collected in a polypropylene bottle. 
The dispersion was then coated onto KAPTON.RTM. substrates within 2-4 
hours using a Gardner laboratory coater. The coated layers were first 
air-dried for approximately two hours and then heat cured in a 
programmable oven. The heating sequence was: (1) 65.degree.C. for 4 hours, 
(2) 93.degree. C. for 2 hours, (3) 144.degree. C. for 2 hours, (4) 
177.degree. C. for 2 hours, (5) 204.degree. C. for 2 hours and (6) 
232.degree. C. for 16 hours. A resistive layer (.about.3 mil) consisting 
of 5% by weight ACCUFLUOR.RTM. 2028 in VITON.RTM. GF was formed. The 
surface resistivity of the layer was measured according to the procedures 
of Example I and was found to be approximately 1.times.10.sup.8 ohm/sq. 
Example VIII 
A resistive layer containing of 5% by weight ACCUFLUOR.RTM. 2028 in 
VITON.RTM. GF was prepared according to the procedures in Example VII, 
with the exception that 1.36 g of DIAK 1 was used as the curative. The 
surface resistivity of the layer was measured at 1.times.10.sup.5 ohm/sq. 
Example IX 
A coating dispersion was prepared by first adding a solvent (200 g of 
methyl ethyl ketone), a steel shot (2300 g) and 1.4 g of ACCUFLUOR.RTM. 
2028 in a is small bench top attritor (model 01A). The mixture was stirred 
for about one minute so that the fluorinated carbon became wet. A polymer 
binder, VITON.RTM. GF (45 g), was then added and the resulting mixture was 
attrited for 30 minutes. A curative package (1.36 g DIAK 3 and 0.2 g 
Maglite Y) and a stabilizing solvent (10 g methanol) were then introduced 
and the resulting mixture was further mixed for another 15 minutes. After 
filtering the steel shot through a wire screen, the fluorinated 
carbon/VITON.RTM. GF dispersion was collected in a polypropylene bottle. 
The dispersion was then coated onto KAPTON.RTM. substrates within 2-4 
hours using a Gardner Laboratory coater. The coated layers were first 
air-dried for approximately 2 hours and then heat cured in a programmable 
oven. The heat curing sequence was: (1) 650.degree. C. for 4 hours, (2) 
93.degree. C. for 2 hours, (3) 144.degree. C. for 2 hours. (4) 
177.degree.C. for 2 hours, (5) 204.degree. C. for 2 hours and (6) 
232.degree. C. for 16 hours. A resistive layer (.about.3 mil) consisting 
of 3% ACCUFLUOR.RTM. 2028 in VITON.RTM. GF was formed. The surface 
resistivity of the layer was approximately 8.times.10.sup.6 ohm/sq. 
Example X 
Resistive layers consisting of 5% ACCUFLUOR.RTM. 2028 in VITON.RTM. GF were 
prepared using the dispersion and coating procedures as outlined in 
Example VII, with the exception that the curing times and the curing 
temperatures were changed. The surface resistivities of these layers are 
summarized in Table 5. 
TABLE 5 
______________________________________ 
Curing Temperature 
Curing time 
Surface Resistivity 
(.degree.C.) (hours) (ohm/sq) 
______________________________________ 
232 2 3.6 .times. 10.sup.8 
232 4.5 1.2 .times. 10.sup.8 
232 8 1.0 .times. 10.sup.8 
195 2 .sup. 1.9 .times. 10.sup.10 
195 4.5 6.0 .times. 10.sup.9 
195 8 7.7 .times. 10.sup.9 
195 23 3.4 .times. 10.sup.9 
175 4.5 .sup. 5.2 .times. 10.sup.10 
175 23 .sup. 2.0 .times. 10.sup.10 
149 8 .sup. 5.2 .times. 10.sup.11 
149 23 .sup. 2.3 .times. 10.sup.11 
______________________________________ 
Example XI 
Resistive layers consisting of 3% by weight ACCUFLUOR.RTM. 2028 in 
VITON.RTM. GF were prepared using the dispersion and coating procedures as 
described in Example IX, with the exception that the curing times and the 
curing temperatures were changed. The surface resistivities of these 
layers are summarized in Table 6. 
TABLE 6 
______________________________________ 
Curing Temperature 
Curing Time 
Surface Resistivity 
(.degree.C.) (hours) (ohm/sq) 
______________________________________ 
235 2.5 8.1 .times. 10.sup.6 
235 6 8.0 .times. 10.sup.6 
235 8 8.0 .times. 10.sup.6 
175 2.5 6.6 .times. 10.sup.8 
175 6 4 .times. 10.sup.8 
175 24 8.8 .times. 10.sup.7 
149 2.5 .sup. 1.2 .times. 10.sup.10 
149 6 7.5 .times. 10.sup.9 
149 8.5 6.1 .times. 10.sup.9 
149 24 2.5 .times. 10.sup.9 
______________________________________ 
Example XII 
A coating dispersion was prepared by first adding a solvent (200 g of 
methyl isobutyl ketone), a steel shot (2300 g) and 8 g of ACCUFLUOR.RTM. 
2028 in a small bench top attritor (model 01A). The mixture was stirred 
for about one minute so that the fluorinated carbon became wet. A polymer 
binder, VITON.RTM. GF (45 g), was then added and the resulting mixture was 
attrited for 30 minutes. A curative package (2.4 g DIAK 3 and 3 g Maglite 
Y) was added and the resulting mixture was further mixed for another 15 
minutes. After filtering the steel shot through a wire screen, the 
ACCUFLUOR.RTM. 2028/VITON.RTM. GF dispersion was collected in a 
polypropylene bottle. The dispersion was then air-sprayed onto KAPTON.RTM. 
substrates. After air-drying for 1-2 hours, the layer (2.4 mil) was heated 
at 175.degree. C. for 3 hours. The surface resistivity and the bulk 
resistivity were determined as outlined in Example I and are 
1.4.times.10.sup.7 ohm/sq and 1.times.10.sup.6 ohm-cm, respectively. 
Example XIII 
Resistive layers consisting of different fluorinated carbons in VITON.RTM. 
GF were prepared according to the procedures described in Example XII. In 
addition to the spray-coating, flow-coating was also used in certain 
dispersions. Flow coating procedures are described in Attorney Reference 
D/96035, U.S. application Ser. No. 08/669,761 filed Jun. 26, 1996, 
entitled, "LEVELING BLADE FOR FLOW COATING PROCESS FOR MANUFACTURE OF 
POLYMERIC PRINTER ROLL AND BELT COMPONENTS;" and Attorney Reference 
D/96036, U.S. application Ser. No. 08/672,493 filed Jun. 26, 1996, 
entitled, "FLOW COATING PROCESS FOR MANUFACTURE OF POLYMERIC PRINTER ROLL 
AND BELT COMPONENTS." The disclosures of both of these applications are 
hereby incorporated by reference in their entirety. 
TABLE 7 
______________________________________ 
Surface Bulk 
Filler in VITON .RTM. GF 
Thickness 
Resistivity 
Resistivity 
(%) (mil) (ohm/sq) (ohm-cm) 
______________________________________ 
10% ACCUFLUOR .RTM. 2010 
1.6 8 .times. 10.sup.4 
1 .times. 10.sup.3 
(by spray) 
(by flow-coating) 
2.3 9 .times. 10.sup.3 
.about.1 .times. 10.sup.3 
10% ACCUFLUOR .RTM. 2010 
4% ACCUFLUOR .RTM. 2028 
(by spray) 2.4 1.5 .times. 10.sup.6 
1 .times. 10.sup.5 
10% ACCUFLUOR .RTM. 2010 
5% ACCUFLUOR .RTM. 2028 
(by spray) 1.5 1.2 .times. 10.sup.6 
1.5 .times. 10.sup.4 
______________________________________ 
Example XIV 
A VITON.RTM. GF layer consisting of about 15% by weight of ACCUFLUOR.RTM. 
2028 was prepared and heat cured according to the procedures described in 
Example I. The surface resistivity of the layer was determined to be 
&gt;10.sup.14 ohm/sq and the volume resistivity was found to be 
.about.1.times.10.sup.13 ohm-cm. A gold electrode (.about.800 .ANG. thick, 
0-25 inch diameter) was evaporated onto a "sister" sample which was coated 
onto a stainless steel substrate. The VITON.RTM. GF layer, which is now 
sandwiched between two electrodes, was subjected to a current treatment by 
increasing the applied voltage incrementally up to 750 V/cm. An amount of 
10 miliamps of DC current was applied to the layer for 10 minutes. The 
bulk resistivity of this layer was decreased to .about.5.times.10.sup.10 
ohm-cm. 
Example XV 
A VITON.RTM. GF layer consisting about 30% by weight of ACCUFLUOR.RTM. 2028 
was prepared according to the procedures outlined in Example I, except 
that this layer was not heat cured. The surface resistivity was &gt;10.sup.14 
ohm/sq and the bulk resistivity was .about.10.sup.13 ohm-cm. This layer 
was then subjected to a current treatment using the procedures set forth 
in Example XIV. In this example, the current treatment lasted for about 2 
hours. After the current treatment, the bulk resistivity of the layer 
decreased to .about.1.2.times.10.sup.9 ohm-cm. 
Example XVI 
About 15 g of ACCUFLUOR.RTM. 2065 was dispersed in 200 g of methyl ethyl 
ketone. A curative package containing 2.25 g of VC 50, 0.9 g Maglite-D and 
0.2 g Ca(OH).sub.2 was added. After mixing, the solvent was removed in an 
evaporator and the contents were dried in a vacuum oven, yielding a gray 
powder sample. When this sample was heated at 235.degree. C. for 16 hours, 
the color of the powder changed from gray to black. 
Example XVII 
The procedures in Example XVI were repeated except that ACCUFLUOR.RTM. 2065 
was heated in the absence of the curative package. No change in color was 
observed. These two experiments demonstrate that the curative causes 
defluorination of ACCUFLUOR.RTM. 2065, leading to a less fluorinated, 
black fluorinated carbon. 
While the invention has been described in detail with reference to specific 
and preferred embodiments, it will be appreciated that various 
modifications and variations will be apparent to the artisan. All such 
modifications and embodiments as may readily occur to one skilled in the 
art are intended to be within the scope of the appended claims.