CA1067326A - Carrier powder with core of metal, sand or glass and a coating of a perfluoro compound - Google Patents

Abstract

TREATMENTS OF IRON POWDERS
WITH PERFLUORO COMPOUNDS
Abstract of the Disclosure Disclosed is a treatment of iron powders with perfluoro compounds. A perfluoro compound is dissolved in an appropriate solvent, then the iron powder is added to and agitated with the solution. After decanting and filtering, the iron powder is dried and a perfluoro coating remains. Iron powders coated in this manner have particular utility as carrier particles of development powders in magnetic brush development units of electrophotography copier equipment.

Description

~OG73Z6 ~ackground of the_Invention With the increased use of plain paper copiers, development powders have en]oyed an increased popularity over liquid toners.
~long with the increased use of development powders, magnetic brush units are becoming increasingly popular as opposed to cas-cading methods. Development powders used with magnetic brush units usually have an iron powder which serves as the carrier material.
,; , . .
Inexpensive, untreated iron powders cannot be used in magnetic brush systems since such iron does not have sufficient stability toward rusting and has color and triboelectric charging properties adv~rsely effected by variable humidity conditions. In order to solve this problem, those in the art have resorted to chemical plating and coating of the iron particles with polymers, oils, waxes and the like.
Prior art developer materials, which are employed in automatic copy machines, have carrier filming problems due to the .:
mechanical rubbing of the carrier surface with the soft toner resins.
The gradual accumulation of permanently attached film impairs the normal triboelectric charging of the toner particles in the toner mix. As a result, the toner is either less hlghly charged or ~ , ;
sometimes oppositely charged giving rise to poor copy quality with a high degree of background.
In the literature, several types o~ plastic coating and electroplating o~ the carrier have been suggested to overcome ;
the filming problems. Most of the prior art coating methods result in high cost and have other disadvantages such as yielding improper triboelectric charge properties and imparting a very high ::.
electrical resistance to the carrier that reduces its development electrode e~ect and results in poorly filled-in large image areas.
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Summary of the Invention In the art of electrostatographic imaging proceq~, an el~ctrostatic latent image is formed on a recording surface of a photoconductor. The electrostatic image may then be deveioped by finely divided toner particles electrostatically attached to the surface of carrier particles. Preferably, the carrier particles are iron powder or beads.
It has be~n found that a simple perfluoro adsorption -. :
treatment of iron powder from a solvent produces a treated iron which has good stability to rusting under high relative humidity, a constan~ triboelectric charge property under all conditions when mixed with standard toners and very low dusting of the toner in a magnetic brush unit and allows the use of lower reverse biased voltage during development which improves the reliability of machine performance.
By using the treated carrier particle~ of this invention, an improved electrophotographic process is obtained. In this improved process, a latent electrostatic image is contacted with J`' .`
a developer mixture including the treated carrier particles of this inventio~.
s; Brief Description of the Drawing The single figure is of a graph showinq the effect of perfluoro component solvent concentration on the charge to weight , ~; ratio of treated iron powder.
Description of the Preferred Embodiment ,~ ~he core of the carrier particle formed by the present ' ~ ~ invention may be any material which can react chemica}ly with the ~-perfluoro compounds of this invention. Thus, by way of example, . " ,.~ .
~- the material of the core of the carrier particle may be sand, gla8s ~,$ beads, metallic beads or metallic powdersO As used in this ~ specification, including the appended claims, the term metal ;
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~0673;26 ~ and metallic is in~ended ~o incl-ldc cleme1ltal metals a5 well .lg .,3 ' their oxides, carbide~ and other forms of mctallic compounds ~; and alloys which have a solid form.
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The core o carri~r particles o the preferred ~mbo~iment -.:. . ~ .
is a ferromagnetic material such as iron or steel. Other suitable ~, ferromagnetic materials such as ma~netic oxid~s and alloys of copper-nickel-iron, for example, also may be employed. The `~ size of the core may be between 40 and l000 microns with the preferred size range being between 50 and 400 microns.

;, 10 The perfluoro compound is selected from a number.of classes including perfluoro alkanes, perfluoro alkyl ethers, perfluoro ; alcohols, perfluoro amines, perfluoro amldes, perfluoro es~ers, :!~ ': : - ' perfluoro acids, and the like.
Perfluoro alkanes of the formula F.(CF2)n.F, where ~ is equal to or greater than 6, can be used. ;Compounds of the type lH perfluoro alkane H.CF2.(CF2)n.CF3 can also be used. Speclfic ~; examples of the first class are~perfluoro hexane, perfluoro~
heptane, pèrfluoro alkane-70,~perfluoro alkane-80, perflaoro .
~ alkane-llS, perfluoro alkane-l95,~perfluoro kerosene-L, perfluoro ~" 20 ~ kerosene-H, e~c. Examples of the~ perfluoro alkane are 1 perfluoro heptane, lH perfluoro octane, etc.
oi ~ Examples of perfluoro alkyl po~y~ethers aré-flQrinated oils such as KRYTOX~143* available from~DuPont de Nemours & Co.
~'t"'~ and FOMBLIN-L*, FOMBLIN-M*, ~OMBLIW-H* and FO1~LIN-U*, all avail~ble from PCR Inc., Gainsville, Florida.
Fluoro alcohols suitable for the treatment~are perfluoro ~ ~`
alcohols of the formula: ~

- ~ ( 2 CF2)n C'~2~1 or ~1.(CF2-cF2?n.cl~2Oll where ~ 7 such as lH, l~1-perfluorooctanol; l11, l11, 911-perfluorononanol;
lH, ll1, l1H-perfluoroundecanol; l11, 111,~311-porfluoroyropanol;

*TradPmark .~ ., " ~

and 111, 111 511-perfluoropentclnol. ~lso suitabl~ are ~econdary and branchcd chain alcohols such as H. ~CF2) 4.C110H.C~13, .(CF2)4.COII(C113)2 and 1~(CF2)8C~I~CH3) C112OII- Other .::
~'" . fluorinated alcohols useful in this invention are o~ the - /.~
formula F. (CF2)n.(C112)m.C1~2OI~ where n is an integer from l-9 .. :
and m is an inteyer from 2 10. ' - .~:
Fluoro amines sui-table for the treatment are primary,~ :
secondary and tertiary perfluoro'amines, for example perfluoro tributyl amine.
. , ~ , - . . . :
' Also usable are fluoro amides of tlle composition F.(CF2)n.CONH2 where n = 4 to 10, for example perfluoro ' ~

' sctanamide. Branched as ~ell as.-C1~2-~sequented amides can .. ' ~ be used.' ~' : Partially fluorinated aliphatic diesters with surface~
.:,; . ~ . ~ .
active compositions may be employed and have the.~f~rmulae~

P (cF2)mOoc CH (CH2)xcOO(cF2)m . and ' :~

~20 ~ H (cF2)nooc CH(CH2)xcOO(cp2)n ~

where R ls hydrogen, C2 to C12~straight~chain alkyl, C2 to C12 1?'~ straight chain alkenyl or phenyl, m is~:an~inte~er from 5~'.to~

;. ~ x~is an integer from 1 to 7 ,~ and n is an integer~from 4~-to 10.

The acid portion of such dlesters may~be, for example, a:

:. succinyl, glu taryl, adipyl, pimelyl, sùberyl, azelayl or:~

. : sebacyl radical; a methyl-,'n-propyl, n-butyl-, n-dodecyl-, -' n-octenyl-, or n-dodecenylsucclnyl~ rndical; a phenylsuccinyl : radical, a 3-methyl-, 3-butyl-,:.3-dodecyl- or 3-~octenylglutaryl radical, a 3-phenylglutaryl radical;:a 4-mçthyl-, 4-octyl or :::............. , , . ~ i " .
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~ ~0~73~;
4-phenyladipyl radical; a 7-mcthyl-- or 7-ethylazelnyl radical;
or a 7-phenylazelayl radical. Typical esters within the above formula are bis-(perfluorooctyl) n-dodecenyl succinate, bis-~perfluorohexyl) 3-methylglutarate, bis-(perfluorooctyl) 3-methylglutarate, bis-(7-hydroperfluoroheptyl) 3~methylglutarate and bis-(7-hydrop~rfluoroheptyl~ 3-phenylglutarate.
Fluoro acid compounds suitable for the treatment are .. . . . .
perfluoroalkyl monocarboxylic acids of the formula:

i F(~F2)nC
0 where n is an integer from 1 to 13, for example: trifluoro ~ acetic acid, heptafluoro butyric acid, ~erfluoro decanoic -~
. - . , . .: , ~
-~ acid, perfluoro-n-octanoic acid, etc., branch chain perfluoro ;
alk~l monocarboY.ylic acids of the formulae~
~ ~ (CF3)2.CF(CF2)n.COOH and (CF3).(CF2Cl).CF.(~F2)n.COOH
t'.'.. ' where n is an integer from 1 to llj and includes 3-tr-ifluoro-methyl perfluoro butanoic acid,~ 3-dlfluorochloro methyl per-fluorobutanoic acidl 13-trifluoromethyl perfluorotetradecanoic acid, etc partially fluorinated monocarboxylic;acids of the formula:
t ~ (CF2)n-(CH2)~;m-~cOoH
~;D~ ~ ~ where n is an integer from 1 to 10 and m is~ an~integer from 2~to 16,~and includes 4-trlfluoro methyl-butanolc acid, ll~(heneico~
fluorodecyl)-undecanolc acid, l7-(penta deca1uoro~heptyl) hepta - ;
~ decanoic acid, etc., and partially fluorinated monocarboxylic t; ~ acids o the~formulaO .
I(CF ) COO~
where n is an integer from 1 to~l4, for example 2~1-difluoro-acetic acid, 7H-dodecafluoro heptanoic aoid, 1111 eicosafluoro undecanoic : acid, etc.

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;73;~6 The abovc classiflc~tion of the perfllloro compound~
that can be used ln the prcscnt invention ls not llmiting. Othcr p~r~luoro compounds such as ke~ones, aldehydes, nltriles, - sulphon$cs, etc. can also be used.
The perfluoro alkanes, ethers, seem to give only temporary protection to the carrier surface. The perfluoro .
amines, amides and esters seem to give fairly lon~ life to the carrier. The longest life is obtained with the acids and - alcohols.
As a typical carrier, ANCOR STEEL~ (Hoegen~es) ?oO0s ~. .
(-80/+230 mesh) Hoegenaes9 Inc~, New ~ersey was used. Spherical ~-; lron powder from ~uclear Metals~Division ~hittaker Concord, Massachusetts was a l s o u s e d .
Commerical toners may be~used iD~conJ~1nction ~ith perfluoro treated iro~a powder. ~Examples o f such commerical toner are ISC l00g-l4A toner made by~Imaglng Systems Corp., Toner 67-146 made by Phillip A. Hunt~Chem1cal~Corp~, and~IBM Toner H 1162058. A non-comr1e~rclal toner~used in combination with tbe ~;
perfluoro treated iron was a composition of 45.~ parts styrene- -~20~ butylmethacrylate copolymer, 45.5 parts Pliolite VTLb (Goodyear Chemclals), 6 parts ~logul-L* (Cabot Corp.3~and 3 parts nigrosine bas~e NB (GAP Corp.).~ This non-commerical toner is herei11after - referred to as PB toner. The p~r~epared toner coTIcentrate in~the , ; ; devel~per mix is between l and~3X, the bnlanco being p~rfluo;ro treated powder.
The perfluoro treatmene of the carrier particle is~ ;
~ccomplshcd by tumbling tl1e core materinl for about 30 to 45 ~minutes in nn approprlate solutlon~cnntaining ~y of tho ; per1uoro compounds enumern~ed previously.~ After tumblin~, t11e ~;

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, :', ~ ' - ' ' ': ' -i. - . ~ ' r ~70673Z6 solution is decanted and filtered and the core m~terial is heated in an oven, for example at 50-75C, untii dry. The treated core material may then be used as a carrier particle , . in.a developm~nt powder.
-Suitable volatile solvents for the l.iquid con.~ositions of the invention are halocarbon solvents such as liquid perfluoro-alkanes and fully fluorinated bromo and chloroalkanes, for example, perfluoropentane, perfluorohexane, trlchlorofluoromethane, dibromo~ ~ ~
: difluoromethane, tribromofluorome~hane, l,l,2-~richloro-l,2,2-tri- : .
fluoroethane, l,2-dibromo-l,l,2,2-tetrafluoroe-thane,l,L,l-trichloro-- 2,2,3,3,3-pentafluoropropane, l,l,1,3-tetrachloro-2,2,3,3-tetra-.
- fluoropropane and 2,2,3-trichloro-ljl,l,3,4,4,4-heptafluorobutane, :~
mixtures thereof, and l,l,2,2-tetrachloro-l r 2-difluoroethane, M.P. ~
26 C., in liquid form or in solution in one of the liquid perfluoro-~-:alkanes or liquid fully florinated bromo or chloroalkanes. : ..
~ Other solvents which may be used include MEK, acetone, ::::
mineral spirits, naptha and the like. It has been found that :
~ . these latter solvents may be mixed with the halocarbon solvents.
listed above for better coating results at.lower cost.
~20A typical concentration range for the perfluoro compound , - to solvent is o. ui - 10%t the preferable range being 0.1-0.2%. ;~
The following perfluoro compounds have been used ~ :
successfully to treat iron powders which are used as carrier~
,.. ~ particles: Perfluorokerosene-L;~ 1,lH, 911-perfluorononanol3;
..(lH, l~-perfluorooctanol); perfluoro decanoic acid; (llH-per~
~:fluoroundecanoic acid)1 perf1uoro-n-octanoic acid ~erfluoro~
octanamide; perfluoro tributylamine; (lH, lH, ll~1-perfluoro~
- undecanol); and perfluoro esters.~- bis ~2,4' pentoxy~

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~L~6~73Z6 ;~etra1uoro propyl)-3-me~lly]~ r,~c all o~ which arr available from rCR, Inc., Gnlnesville, Florid~. In addition, perfluoro .. . .
allcyl ethers, avalla~le from E.I. ~uPont de'Nemours Chemical Corporation, Wlll~ington, Delaware, und'er thc trademark KRYTOX.
Preferably the perfluoro treatcd iron is mixed with a toner at a ratio of 98:2 respectlvely. These ratios are hased~ ~' on weight as are all ratio and percentage fi~llres in this '~
specification. The developer powdcr is evaluated using the-~' following tests~
' 10 A. Faraday Cup measurement: these are carried out `
'- as a function of perfluor~o treatment and expDsure to ~- various humidity conditions. It yields a charge ~o mass measurement that indicates the effecti~erLess of the treatment.
I . . .
:~ B. Step tablet measurements: this~gives an indication - as to toning'characteristics oi~ the developer powder.
lectrica].ly insolated spots o 1 CD ~1n diamete~r nre~
` ' back charged in potentials of increasing ~oltage end ~; ~ ' increments of 10 V. These spots are developed to ~- 20 ~ completion with the developmel~t powders flom a manual magnetic brush. The spots are evaluated for print .. : . .: : :
' ~ ~ - de~sity fill ln and other'visually observab-le ~ ' Ç ' charocteristics,~

C. Machine evaluation of the developer powder in a - '~

'`~ plain paper copier such as the PBC~4500 Copier*, '~ Copier Division, Pi~ney-Bowes, Inc., Danbury, Conn.
: : , . . ~ : .
~-~ Table 1 lists the Faraday~Cup measurements. It is ~ ;
seen that the treatmen~ affects the triboelectric property of the~
lron sur~ace a;ld as a result, one may obtaill any deslred CIM

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~i73Z6 ratio by choo9in~ the propcr pcrfluoro compound. The third colu~n glve9 the C/M aftcr the dcveloper~ havc be¢n ex~oce~ ~D
75Z/R'l at 68 F. for 3-4 day6. The ~st column gives the per- .
centage drop ln C/~ whQn the deveioper powder is exposed to hi~h : . ' ' . :: ' : R.H. .
Ideally one would like to have no drol? in CJM at hi~l ;~ R.H.
TABLE I

Charge Charge coul/g ~-coulJg ~ Percent ::
~ Room 75/RH 68 F ~ Char~e : Compound . Condition for 3-4 days: of Char~e :::
Untreated Iron . 4.8 .~: 3.4 ~ 29.7 ~ Washed~with Solvent ~ 4.0;~. ~ 3.3 16.0 ; ~- Perfluorokerosene.L ;~ 4~.6~ 2.4~ ~~ 32.6 ^~
- : Perf].uoro Alkyl Ethers ~ ~6.. 4~ S.O -~ 22.4 :~
Krytox from DuPont) , lH, 9ll-Perfluorononanol ~ 5.6~ 4.0 ~ ~ 28 20 ~. lH, lH-Perfluorooctanol: 7.8 ~ 6.3 : 19.6 Perfluoro Decanolc Acid ;~ ll.9 :~ 9.3 ~ ~ 21.8 : : llH-Perfluoroundecanoic .: :9.1 :~ 9.2 ~ ~1.4 :

Perfluoro-N-Octanoic Acid ; ~ Cha~rge Reversa}
Per~luoro.Octanamide ~ ~10.9~ .;9.5 ~ . 12.8;::~
:: Perfluoro Tributylamine 5.0~ 4.0 ~ 19.4:~
lH, lH, ll~-Pereluoroundecanol 7~.~8 ~ 6.5 19.5 :.:: . . , : . , ~: ~
~ The perfluoro concentrate in~tlle soluLion was 0.2% in all cases except in ~5 where it was .O5 The ~raph~of the dra~lnE~shows the ~ypical eE~fect o f ~
: . . :conccntrate of perfluoro compoun~ on C/M. The curve ~a~ obtained 8p ~

"'' '' ' ' .. ' ,',.:' ' , ,, '' '' ' - , - . '`'' , , , . ~ .
'.' ~ : ' ' '' , , ', : ` : , ~:-~1~)673Z~
for iron pol~cr tr~c~l wltll 1111 ycr~luorollndecanoic acld.
It i8 secn th~t the C/M incrcns~s r~pldly, rcacllc~ a pla~enu until hl~her concentrations are reac!led, tbcn the C/N
.dec~eases. . . .
: - Example.I
s A quantity of 0~05 gms. of ll~ perfluoroundccanoic acid W~5 dissolved in a mixture of 20cc trichloro hept~luoro butane (HALOCARBON # 437, Haloc~rbon Co., New ~ersey~ and 10cc . ~ . ' - -;. . - .- - . , : -.

10a ~: dup/p~

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- ~673Z6 ~

of me~h~l ethyl ketone. To this solvent wai~ added 30 gm. of iron powdes (Anchor Steel lOOOS) having a mesh of -80~230. The ci~ntents were mixed for 1/2 hour and then the supernatent wais ~ecanted. The remaining treated iron powder was dried in an oven at 100 C. for two hours. This treated iron powder was mixed with tha ISC toner lOOg-14A in a ratio of 98:2 respectively. The davelop-ent powder wa~ used intermediately over a 6 month period and t.:
was ~o~-d to retain its excellent propertie Good results were achieved when used to produce plain paper copi~s in a P~C copierO

Example II
. . - .
guan~ity of 0.05 gms. of tper~luoro kerosene-L) was~
~,~ dissolvad in a mixture of 20cc trichloro heptafluoro butan~ and lOcc of ~ethyl eth~l ketone. ~o thii3 solvent was added 30 gm.~ of~
iron po~de~ (A~chor Steel lOOOs) having a~mesh of 80+230. The contents were .~ixed for 1/2 hour and then~the supernatent was ` dicanted. The re~ininS treated iron powder was dried in ~
oven at 100 C. for two hours. ~This treated~iron powder was mixed wlth the ISC toner lOOg-14A in a ratio o~ 98:2 respectively. ~ s si~ ~ A quantity of 0.05 gms. o~ (Xrytox) acid was~dissolved in a ~ixturs of 20cc~trichloro heptafluoro butane and lOcc o~ methyl ethyl ke~one. To th$s solvent was added 30~gm. oS lron powder nchor Steel lOOOS) having a mesh o~ -80~230. The content3 ~
~; were mixed ~or 1/2 hour and then the i~upernatent was decanted.
The ~e~aining treate~ iron powder was dried in an oven at 100 C.
or two hours. This treated iron powder was mixed wlth the ISC
$ - toner lO~g-14A in a ratio o~ 98:2 respectively. The developm~nt~
.~J" po~der waY used intermediately over a 6 Nonth period~and was ~ound to ret~in its excellent p~opertie~. Good~results were achieved when used in a PBC copier.

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-673Z6 - ~
ExampJc IV
A quantlty of 0.05 ~ms. of lH, 1ll,, ~ pcrfluorononanol wa~ dissolved in 30cc o~ a solvent made up of 67 parts Freon-ll*
(DuPon~) and 33 part~ methyl cthyl ketone. To this solution was added 30 gm. of iron powder (Anchor Steel lOOOS~ having a mesh of -80+230. The contents were mixed for 1/2 hour and then the supernatent was decnnt~d. The remaining treatod iron powder was dried in an oven at lOO~C. for two hours. This t'reated iron po~der was mixed with the ISC toner lOOg-14A in a ratio of 98:2, respectively. The development powder ~as used intermedia~ely' :, . . : . , '- o,ver a 6 month period and was found to retain its excellent propert$es. Excellent plain paper copies were produ~ced in a . .
,' ~- PBC copier uslng this development powder. -' ~ Example V
~ A quantity of 0.05 gms. of perfluDro decano$c acid uas ,''~ diss'olved in 30cc of a mixture made up of~67 parts Freon-ll ~'' (DuPont) and 33 parts methyl ethyl ketone.'~ To this~solven~
was added 30 gm. of iron powder~(~Dchor Steel~lOOOS) having a, .mesh of -80+230. The contents were~mixed ~or 1/2 hour and~Lhen ~,20 the supernatent was decanted. The~remain~ing~ tre=ted iron poader was dried in an oven at 100C.'for two hours. This treatcd iron ~-' powder was mixed with the ISC toner~lOOg-lbA~in a ratio of 98:2 ,~
respectiveiy. This development powder was used in a PBC copier ,-' intermediately over a six month per~iod and gave good results.
Example VI
~ A quantity of~O'.05 gms. of perfluoro n-oceanoic acid ~" ;' ." ~ was dissolved in 30cc of a mixture of 67 pnrts Freon-ll* (Duront~
k : and 33 parts methyl ethyl kctone. To this solvent was added ,,~ 30 gm. of iron powder (~nchor S~e'ol lOOO.S) having'a mcsh ' '~

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~ 73~26 ~f 80t230. Thc ~on~cncs wcrc ml~cd for 1/2 hour .Ind tllcn ~he supern~tent w~ decan~ed. Tha rem~inln~ t:re~ted lron powder was dried in ~n ovcn, This treated lron powder was mlxed wlth the ISC toner 100~-14A in a r~tio of 98:2 respectlvely ~nd tlle development powder was te~ted. ~ood propcrtles resul~ed.
Ex~mple VII
A quantity o 0.05 ~ms. of perfluoro octanamlde acid -was dlssolved in a mix~ure made up of 67 parts Freon-ll (DuPont) ~
and 33 parts methyl ethyl ketone. To this solvent ~las added : , 30 gm. of iron powder (Anchor Steel lOOOS) having mesll of -80+230. The contents were mixed for 1/2 llour and then the supernatent was decanted. The remaining treated iron powder was dried in an oven at~100C. for two hours. ~This treated iron powder was mixed with the ISC toner lOOg-14A in a ratio of 98:2 respectively. The development powder was~ used in a~PBC copier intermediately o~er a six month period and wa~ found to yield good results.
Bxample VIII
A quantity of 0.05 gr,ls.~ of (perfluoro tributylamine)~
was dissolved~in a Freon TA (Du~o~t). To~thls solv;en~t was added 30 gm. of iron powder (Anchor Stee~l lOOOS) having a mesh of :
80+230. The contzllts were mixed for 1i2~hour, the supernatent was decanted, and the remaining trèated`i~ro~n powder wae dried. ~-This ~reated iron powder was mixed~ Witll the ISC toner lOOg-14~ -in a ratio of 98:2 respectively,~ Good properties wDre obtalned vhDn the development powder wDs t~sted.
x~mple_IX
A quantlty of 0.05 gms. of 111, 1}1, llll-perfluoroundecaDol wa8 dissolved in 30cc Preon TA (DuPon~). To this solvent aDs ;~

* Trademark ~ - 13 dDp/~h s~B - ~ ;

.. . . . ~ . -. ~ ~ ~
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;
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' ~673~6 n~d~d 100 E~ of lron powdf~r (Ancl~or S~ccl lOOOS) havLn~ .i me~h of 80+230. The contellt~ were mixed for l/2 hour a,nd then ~lle supernatent was decanted. The remalnin~ treated iron powder wns drlbd ln an ovcn a~ 100C~ for two hours. This treated iron powder was m'ixed wlth the ISC toner 100~-]4A in a ratio of 98:2 ref~pectively. The development powd~r was tested in a PBC copier intermediately over a six month period and was found to yield good results as well as retain its excellent properties.

.. . .
' I xample -A quantity of 0.05 gms. of llll-perEluoroundecanoic 'acid was dissolved in Q mixture of 20cc trichloro lleptafluoro butane (HALOCARBON #437, ~alocarbon Co., New~Jersey) and lOcc of methyl ethyl ketone. To this solvant was added 50 g~. of~
~hitaker iron powder having a mesh'of -80~230. The iron is mixed .. - - , ~ : ,: . .
' ~ with ISC lOOg-14A toner at a concentratlon oE 2X~and evaluated~
',~ in a PBC copier. The contents,were' mixed for i~2 hour and then '' ~' -~ the supernatent was decanted. The remaining treated iron powder , was dried in an oven at 100C. for'two hours. Tliis treated iron powder was mixed ~ith'the ISC lOOg-14A~toner~at a concentration~
.: ~ . : , . - ,~
of 2%. The development powder was~evaluated in a PBC copier ' and~used intermediately over a six month period. Excellent resules wero achieved.
~XAMPLE XI
'' ~ A quantity of 0.05 gms. of llH-perfluoroùndecanoic ', ' scid ~as dissolv~d in a mixture of 20cc trichloro heptafluoro ,. . . .
' butane (HALOC~RBON #437,-!l locarbofn Co., New ~ferseyj and lOcc - _ . , ~ . . . -$ -~ ; ~f mechyl et!~yl ketone. To~thi6 solvent~was added lOO gm. of '~

~' ~ron powder ~Anchor Stcel lOOOS) havin~ a mesh of -80~230. The~

'" ~ contents were mixèd for~l/2 hour and tben th~e supernaeent ~fas ,~

f" - -d~pir~

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. -; : . . .
.. . . . . .
- , ~

3;~6 dec~nted. The r~m~inlng tre~ted iron powdcr was dri~d ln ln OVCII
a~ 100C. for two hcurs. Thl~ ~reated lron powder was blol~dc~ -with PB toner ln a ratio of 97.6:2.4 respectively. The resultlne devclopment powdcr was t~sted in a PBC copicr intermediatPly . . .
over a slx moDtll period and ex&ellc~t res~llts were acllieved.
Example XII
A quantity of 0.05 gms. of llH-perfluoroundecanoic acid was dissolved in a mixture of 20cc trichloro heptafluoro butane (~IALOCARBON #437, Halocarbon Co., New Jersey) and lOcc .. . . .
of methyl ethyl ketone. To this solvent was added 30 gm. o~

iron powder (Anchor Steel lOOOS) having a mesh of -80+230. Tlie - . ..
contents were mixed for 1/2 hour and then the supernatent was decanted. The remaining treated iron powder was dri-ed in an oven at 100C. for two hours. This treated iron powder was mixecl ~--with the Hunt toner #67-146 in;~a ratio of ~7.6:2.4 respectively.
- The pllysical properties of the development~powder was tested and f~und to be hi~hly satisfactory.
~ - Example~XIlI
,` - ~ A quantity of 0.05 gms. of llH-perfluoroundecanoic -~ 20 acid was dissolved in a mixture of 20cc~tT~ichloro heptafluoro ~~
- but~ne (HALOCARBO~ #437, HalDcarbon, Co.~ New~Jersey) and lOcc - of methyl ethyl ketone. To this solvent~was added 100 ~m. o~f ~;
~ . iron powder (Anchor Steel lOOOS) having-a mesh of -80~230. The ;~
i~ ~ content were mixed for l/2 hour and then the supernatent was decantedO The remailling treated~iron powder was~dr;ied in an oven at 100C. for ~wo hours. thi8 ~reated iron powder was mix~d with the I~M Copier II toner in a ratio of~98:2 r~spectiv~ly.

~''.` : ' ' ' ' ' ' .: ~-~ d~p/~hJ

, - . . ' ' ~ . ,': ' .
~ ~ ' .
: ' , - ' .
., , , ~ .
, . : ~:
'',':'` ' ' '' ' '. '.""'.. ',' ' ~' , 73;~6 ;~ . ' , Copies produced in those tests above wherein the development powder was used in a copier showed good fill-in, good resolution and low background. The copier in each instance was operated at -100 volts bias instead of the standard level of 135 volts. The lower bias is possible because of the characteristics resulting from the perfluoro treatment. Additionally, iron pull-out was reduced to 10~ of what was previously experienced without perfluoro carrier particles.
It will be appreciated that the ratios of iron powder to toner disclosed in the above examples are for development powders newly charged to a copier and tlqt the development powder had to be replenished with toner and carrier particles in proper proportion -:: .-: , .
as the same were consumed.

~:~ What is claimed is:
'' , ~ ~ .
,':

:~": ' ' ~'` . :

1 :
.
,.
.:-:
~,.,: ~ :
..
., .
,'.'','~, ~', .

, - 16 - ~ ;
.:
;,-'; ' . ' ' ~ . ~ , ~ ''','.';' .' '' ` " ,' ' " ' ' ', ' ' ' ' ` ' ' .

Claims (37)

1. THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
   PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
   l. A carrier particle for a development powder comprising a core selected from the group consisting of metal, sand and glass, said core being coated with a perfluoro compound selected from the group consisting of perfluoro alkanes, perfluoro alkyl polyethers, perfluoro alcohols, perfluoro amines, perfluoro amides, perfluoro esters and perfluoro acids.
2. 2. The carrier particle of claim 1 wherein said core is iron.
3. 3. The carrier particle of claim 2 wherein said core is between 40 and 1000 microns.
4. 4. The carrier particle of claim 3 wherein said core is between 50 and 400 microns.
5. 5. The carrier particle of claim 2 wherein said perfluoro compound is selected from the group consisting of perfluoro hexane, perfluoro heptane, perfluoro alkane-70, perfluoro alkane-80, perfluoro alkane-195, perfluoro kerosene-L, perfluoro kerosene-H, 1H perfluoro-heptane and 1H perfluoro octane.
6. 6. The carrier particle of claim 2 wherein said perfluoro compound is selected from the group consisting of 1H, 1H-perfluorooctanol; 1H, 1H, 9H-perfluorononanol; 1H, 1H, 3H-perfluoropropanol 1H, 1H, 5H-perfluoropentanol; 1H, 1H, 11H-perfluoroundecanol; H(CF2)8CH(CH3)CH2OH; H?(CF2)4?CHOH CH3; and H?(CF2)4?COH(CH3)2.
7. 7. The carrier particle of claim 2 wherein said perfluoro compound is selected from the group consisting of a fluorinated amide of the formula F(CF2)nCONH2, where n is an integer of from 4 to 10; and a partially fluorinated aliphatic diester of the formula or where R is H, C1-C12 straight chain alkyl, C2-C12 straight chain alkenyl or phenyl, x is an integer of from 1-6, m is an integer of from 5-11 and n is an integer of from 4-10.
8. 8. The carrier particle of claim 2 wherein said perfluoro compound is selected from the group consisting of perfluoroalkyl monocarboxylic acids having the formula F(CF2)n?COOH where n is an integer from 1 to 13; branched chain perfluoro alkyl mono-carboxylic acids having the formulae (CF3)2?CF(CF2)n?COOH and (CF3)?(CF2C1)?CF?(CF2)n?COOH where n is an integer from 1 to 11; partially fluorinated monocarboxylic acids having the formula F?(CF2)n?(CH2)m?COOH where n is an integer from 1 to 10 and m is an integer from 2 to 16; and partially fluorinated monocarboxylic acids having the formula H(CF2)n?COOH where n is an integer from 1 to 14.
9. 9. The carrier particle of claim 1 wherein said perfluoro compound is a perfluoro alkyl ether.
10. 10. The carrier particle of claim 1 wherein said perfluoro compound is 1H, 1H, 9H-perfluorononanol.
11. 11. The carrier particle of claim 1 wherein said perfluoro compound is 1H, 1H-perfluorooctanol.
12. 12. The carrier particle of claim 1 wherein said:
    perfluoro compound is perfluoro decanoic acid.
13. 13. The carrier particle of claim 1 wherein said perfluoro compound is 11H-perfluoroundecanoic acid.
14. 14. The carrier particle of claim 1 wherein said perfluoro compound is perfluoro-N-octanoic acid.
15. 15. The carrier particle of claim 1 wherein said perfluoro compound is perfluoro octanamide.
16. 16. The carrier particle of claim 1 wherein said perfluoro compound is perfluoro tributylamine.
17. 17. The carrier particle of claim 1 wherein said perfluoro compound is 1H, 1H, 11H-perfluoroundecanol.
18. 18. In a method of producing a perfluoro treated carrier particle of a development powder, the steps comprising:
    a. mixing a perfluoro compound selected from the group consisting of perfluoro alkanes, perfluoro alkyl polyethers, perfluoro alcohols, perfluoro amines, perfluoro amides, perfluoro esters and perfluoro acids, with an organic solvent in a con-centration of 0.01 to 10% by weight;
    b. placing a core material into said solution, the core material being selected from the group consisting of metal, sand and glass;
    c. decanting the solution, and d. drying the treated carrier particles.
19. 19. The method of claim 18 wherein said core is iron.
20. 20. The method of claim 19 wherein said core is between 40 and 1000 microns.
21. 21. The method of claim 20 wherein said core is between 50 and 400 microns.
22. 22. The method of claim 19 wherein said perfluoro compound is selected from the group consisting of perfluoro hexane, perfluoro heptane, perfluoro alkane-70, perfluoro alkane-80, per-fluoro alkane-195, perfluoro kerosene-L, perfluoro kerosene-H, 1H perfluoro heptane and 1H perfluoro octane.
23. 23. The method of claim 19 wherein said perfluoro compound is selected from the group consisting of 1H, 1H-perfluoro-octanol; 1H, 1H, 9H-perfluorononanol; 1H, 1H, 3H-perfluoropropanol;
    1H, 1H, 5H-perfluoropentanol; 1H, 1H, 11H-perfluoroundecanol;
    H(CH2)8CH(CH3)CH2OH; H.(CF2)4.CHOH CH3; and H.(CF2)4.COH(CH3)2.
24. 24. The method of claim 19 wherein said perfluoro compound is selected from the group consisting of fluorinated amides of the formula F(CF2)nCONH2, where n is an integer of from 4 to 10; and partially fluorinated aliphatic diesters of the formula or where R is H, C1-C12 straight chain alkyl, C2-C12 straight chain alkenyl or phenyl, x is an integer of from 1-6, m is an integer of from 5-11 and n is an integer of from 4-10.
25. 25. The method of claim 19 wherein said perfluoro compound is selected from the group consisting of perfluoroalkyl monocarboxylic acids having a formula F(CF2)n.COOH where n is an integer from 1 to 13; branched chain perfluoro alkyl mono-carboxylic acids having the formulae (CF3)2?CF(CF2)n?COOH and (CF3)?(CF2Cl)?CF?(CF2)n?COOH
    where n is an integer from 1 to 11; partially fluorinated monocarboxylic acids having the formula F?(CF2)n?(CH2)m?COOH
    where n is an integer from 1 to 10 and m is an integer from 2 to 16; and partially fluorinated monocarboxylic acids having the formula H(CF2)n?COOH where n is an integer from 1 to 14.
26. 26. The method of claim 18 wherein said perfluoro compound is a perfluoro alkyl ether.
27. 27. The method of claim 18 wherein said perfluoro compound is 1H, 1H, 9H-perfluorononanol.
28. 28. The method of claim 18 wherein said perfluoro compound is 1H, 1H-perfluorooctantol
29. 29. The method of claim 18 wherein said perfluoro compound is perfluoro decanoic acid.
30. 30. The method of claim 18 wherein said perfluoro compound is 11H-perfluoroundecanoic acid.
31. 31. The method of claim 18 wherein said perfluoro compound is perfluoro-N-octanoic acid.
32. 32. The method of claim 18 wherein said perfluoro compound is perfluoro octanamide.
33. 33. The method of claim 18 wherein said perfluoro compound is perfluoro tributylamine.
34. 34. The method of claim 18 wherein said perfluoro compound is 1H, 1H, 11H-perfluoroundecanol.
35. 35. The method of claim 18 wherein said solvent is a halocarbon solvent.
36. 36. The method of claim 18 wherein said solvent is selected from the group consisting of methyl ethyl ketone, acetone, mineral spirits and naptha.
37. 37. An electrostatographic imaging process comprising the steps of forming an electrostatic latent image on a recording surface and contacting said electrostatic latent image with a development powder comprising finely-divided toner particles electrostatically attached to the surface of carrier particles, said carrier particles comprising a core selected from the group consisting of metal, sand and glass, said core being coated with a perfluoro compound selected from the group consist-ing of perfluoro alkanes, perfluoro alkyl poly ethers, perfluoro alcohols, perfluoro amines, perfluoro amides, perfluoro esters and perfluoro acids.