Note: Descriptions are shown in the official language in which they were submitted.
WO 94118196 PCTIIJS94/06004
2183~1
MULTIPLF SOLVFNT ~I F~NlN~i SYSTEM
, 5 The present rr, ' liu,, is a continuation-in-part l~ r Jn of
Serial 801,199 fiied December 2, 1991.
Technical Field
The present invention relates to a method and apparatus of
cleaning c~ tu;i articles and apparatus thereof and, more
particularly, to the defluxing or du~ of parts in a non-aqueous
cleaning system utilizing an organic solvent for cleaning the parts and
a l,ollrl.,ll.,,, ' ' fluo,uc~l,L.ùn solvent.
Backgrm ~nd Art
Soivent vapor phase ~ E ~ il,g and defluxing is a process of
.ai~l9 a soiled substrate (e.g., a printed circuit board or a
r.lb~; ' metal, glass, ceramie, plastie, or ~ LU"~O~ part or
co,ll~,ù~il6) into a boilin~, nul.~' lll ' ' liquid sueh as a c,l,'~ o~,Lon
20 or chloroflu~ Lùll fluid or admixture, followed by rinsing the part in
a second tank or cleaning zone by il""~ ,iun or distillate spray with a
elr~an solvent whieh is the same ~,l ' uca~Lùn or ehloroflu~luc-.,Lùn as
used in the first eleaning zone. The parts are then dried by
the eooled part in the eon~ia~l:,in,q vapûrs until temperature
- 25 has reaehed equilibrium.
Solvent eleani~ of various types of p~rts generally oeeurs in
bateh, hu;Jt . ~ bateh, eonveyor bateh, or in-line typ~ conveyor
- ~ and defluxer qlui~ I~. Such in-line eonveyor degreaser
and defluxer eql . ,_.ll are diselosed in U.S. 5,007,179 Patent
-1-
WO 94/28196 2~Ç~!3351 PCT/US94/06004
(entitled "Cold Air Lock Vapor Seal"), ~o,.,,,,onl~l assigned to the
assignee of the present invention. Parts may also be cleaned in open
top defluxing or d~a~,~a:,i"g eq~ ij "~:"~, such as that disclosed in U.S. ..
Patent ~rF" lion Serial No. 07/587,893, filed Seult,lllL~, 25, 1990,
also co"""onl~ assigned. In both types of equipment, the entrance
and/or exit ends of the eq~ i~ "_.,l are generally in open
communication with both the ambient env;,u"",t",L and the solvent
within the equipment. In order to minimize the loss of solvent from
the eq~i",_.,l by either convection or diffusion, a common practice in
the art is to use water-cooled or ~r~ ,a"L-cooled coils which create a
co~ ,.,s~d vapor blanket over a hot or ambient zone region in the
deqreaser/defluxer tank, such as disclosed in U.S. Patent 4,261,111
to Rand.
Therefore, in the foregoin~ solvent vapor phase d~ aai"g
process, it is generally known to use a single organic ~ lvlu~ Lol~ or
chloroflu~luuallJùn (CFC) fluid to perform the cleaning, rinsing, and
dryinq steps. The use of CFC-1 13 and Freon type solvents have been,
in the past, particularly popular. However, the vapor diffusion thereof
into the ~ .u"",~ has been . ' ' in recent scientihc studies to
be one of many possible contributing causes to the u.,d~ ,;,, ' ' global
depletion of a~dtu~ ozone, and the production and use of such
chlorofluo~ Lùns is currently regulated and will be phased out in
the U.S. by the end of this decade.
In response to c.,~;.v.llll_.lL.-l concern, I,,d~u..l ' urluu.u~,.,.uù,~
25 (HCFC~ based solvents have been d~ p~d in the last few years to
provide more e..~:.u.".,_. ~y acc ,: ' ' alternatives to CFC based
vapor phase d_e~ 9 and defluxing ~1uCaa3e5. While these
materials have been shown to be excellent CFC substitutes for a
variety of cleaning ., ' - )s, they are cOlla;d~(~d to be aA interim
WO 94128196 ~ 1. 6 3 3 ~ :~ PCTNS94106004
,~plac~;."e"l to CFCs since they still possess a small, but finite, ozone
depletion potential, although it is much lower than that of the CFCs
, which they are replacing. Hence, these HCFC solvents are also
proposed for global phaseout in the near future. It is generally
believed that organic solvents which do not contain chlorine, bromine,
or iodine atoms will not contribute to ~ Iu~ (ic ozone depletion.
However, organie cl)~n;~ which do not contain the above halogen
atoms, such as hyJ~u~.all,ù,~s, alcohols, esters, ethers, ketones, etc.,
usually contain u-,d~i- ' ' llan... ' " y or reactivity ,u-uu~
10 Perfluorinated lltJ.ù~,alLùl~:~ and lltJ~ Olu~.aluOl~s possess many
desirable solvent p,up~,.t;~.~. zero ozone depletion potential; stable,
non-reactive, high eu..,~ ' ~y with plasties; good water
d;.~,ulà~...,ll~..ll potential; generally non-toxie and inert, and ideally suited
to vapor phase solvent eleaning ~q~i"-~,.l. However,
15 perfluu.u-,a.LGns have been found to be very poor solvents for many
~ommon organic and inorganic soils, e.g., fluxes. Hydroflu~luc~-uons
offer improved but still limited cleaning ability over perfl--u- U~,al uù-)S as
the amount of fluorine content on the molecule " - .;sl-~s, but low
fluorine-content hydrofluu.u~,a,Lons may start to exhibit u.. ' , ' '
20 rla.~.... ' "~y p~u~ 5 COIll,ua~ ' ' to their l.tJ~ùca~bon analogs.
European Patent Publication 431,458 published June 12, 1991
teaehes aliphatie hydrOflu~,uca~Lol~s of the formula CnFmH2n+2m
wherein 4sns6 and 6sms12 whieh are useful as eleaning
cu...~ ls. Thr~ referenee teaehes that the aliphatie
25 l~tJ~Jr~ul,a~lJùn is the aetive cu~ uùn_.~l in th~ removal of the
fluxes, fats and oiis, and dust from soiled parts. The referenee
teaehes that in order to inerease the solveney for Jk...olv;. ,9 fluxes, an
organie solvent seleeted from Il~Jlu~.alLOl~s~ aleohols, esters, and
ketones may be added in an amount from 0.5 to 30 weight pereent to
WO 94/28196 PCT/US94/06004
~,~6~3~
the aliphatic hvdrofluo,uca,uon.
Other types of cleaning p(oc~sses such as aqueous cleaning
exist. Aqueous cleaning generally involves the cleaning of a substrate
or a part in an aqueous solution of dt,l-i,y~ or surfactants, followed
5 by multiple rinsing steps with purified water. The part is then dried by
lengthy ~dpGI aliùn in air or by energy intensive thermal drying
machines. This process is not always desirable due to the high energy
cost for drying and the additional capitai ill~ lll and operating
cost burden to provide aqueous waste water cleanup required by state
10 and local authorities before sewering to ground water.
Another cleaning process, semi-aqueous cleaning, consists of
cleaning a substratd in a ~ J,u~,a,L.on solvent based on, for example,
terpenes, esters, or petroleum distillates having a high affinity for oils,
waxes, and greases being cleaned from the parts, with or without the
15 aid of a surfactant. The cleaned substrate is rinsed of the high boiling
~,yJ~u.,a,Lu,~ solvent with multiple rinsing steps using purified water.
The l.,~J~u~.a.Lon solvent is phase separated back to the wash surnp
while the aqueous effluent must be ,u,uc6..a~,d before sewering to
ground water. Consequentiy, hiQh costs -_..,. ;AI. ~i with drying
20 energy and with ~ ,9 waste effluent are evident, similar to the
before-",.,.,: )~d aqueous cleaning process. A further drawback is
that the l.~J~ uual L~n solvent usually p~ `'i3; a flash point and this
must be cardfully handled or blanketed with a nu~la~,.". ' '
c~".,J.dsaod çiaS such as nitroçien to avoid explosion. Nitro~qen gas is
25 much more fu,qitive than the dense vapors of a fluu,u.,a,Lon contained
in a cu, ,~., .;"~ zone. Ful li ~ u~ in a number of ~ s, while
the substrate to be cleaned may be cu.." ' ' with the l.~J,u~.a,von
solvent, some plastics or metals may be i..cu..,~ ' with the
aque_~ rinse solvent, resulting in water aL:IOllJ~iv~ or rusting of the
wo 94/28196 PcrNss4/o6oo4
substrate.
C~ic~lnc~e of the Invention
. It is acco, ~" ,yly one object of the present invention to provide a
non-aqueous cleaning system for d,~u, "aa;"g or defluxing parts in an
~ /;,ù"",~ "y safe manner.
Another objsct of the invention is to provide a non-aqueous
cleaning system which does not use water for rinsing, and there does
not exist a necesâity for aqueous waste water cleanup, and whereby
said nonaqueous cleaning system can be used in cases where
materials are ill~,Ull~r_ ' ' with watet.
Still a further object is to provide a non-aqueous cleaning
system avoidin~q the need for drying by lengthy e~ Jul"Liûn of rinsing
fluid in air or by energy intensive thermal drying methods.
Yet a further object is to provide a non-aqueous cleaning
system ublizing an organic liquid cleaning agent for cleaning the parts
and a rinsing agent having at least a slight solubility for the organic
cleaner for rinsing the organic cleaner from the part and which rinsing
agent is capable of drying from the part using small amounts of
anergy.
A non-aqueous cleaning proces$ for removing residual soils or
surface cul~h-- ". lion from a part, in ~ "ce with the present
invenbon, cu~l~uli--s the steps of introducing the part into contact
with an or~anic cleaning fluid of sufficient solvency to suL~L~., "y
remove said CCr~h~ r liol~ and then removin~ the part from the
or~qanic fluid for rinsing in a rinsin~q agent havin,q at least some degree
of solubility for the organic cleaner to remove same from the
~,uL ,1. The substrate is immersed in the rinsing a~qent, sprayed
with the rinsin~q a~qent or exposed to vapors of the rinsin~q a,qent, or
any c~.. alio~l of the aboYe. When removed from the vapor, the
WO 94/28196 ~63~ PCT/US94/06004
part is ess6"~iil!y clean and dry. r~l~r~laiJly, the non-aqueous cleaning
system of this invention utilizes a two tank cleaning process wherein a
first tank contains the organic solvent and a second tank contains the ~.
rinsing agent. The parts or substrates to be cleaned may be
conveyored from the cleaning tank to the rinsing tank utilizing known
conveyor or hoist means. The tanks may be part of c~"~ lion~l or
known in-iine c~ o~ d d~u,t,asi"g/defluxing ~ "t."l. separate
open top defluxing tanks, or open top defluxing tanks modified to
contain the cleaning and rinsing tanks or sumps.
In accu,.la,)ce with another feature of the invention, a non-
aqueous cleaning process for removing residual soils or surface
cunlalll' ~aliOIl from parts C~llp~ia~S the steps of introducing the
substrate or part into an organic fluid of sufficient solvency to remove
residual CGrla-l- lal;on from the parts. The parts are then rinsed by
contact with a second or,qanic solvent of lesser solvency for the soils
or surface co"la".;.-aliùn than exhibited by the first organic fluid
solvent but having exc~llent solvency l,llalal,k,li:.li..a towards the first
solvent. The second solvent (rinsin~ a~qent) may be chosen rJ,t,r~lai,ly
from the fluo,u.,a,iJùn class of solvents which contain at least one
20 fluorine atom attached to an organic backbone cc,.."~r;s~d of two or
more carbon atoms, with optionally other atoms also attached to the
backbone such as oxy~en, sulfur, nitro~en, ~ G~ ulues~ hydrogen, or
other haloien atoms; or less r~ aiJly the rinsing a~ent may be
chosen from other classes of solv~nts such as alcohols, ethers, esters,
25 ketones, I,~ ùca.L~n;., snd other non-aqueous media. The parts are
then dried by holding under an inert vapor bianket which lessens or
mitigates the r ", ~ ty of the first orianic cleaning solvent, or, if
r' 111. ' ' . the second rinse solvrnt, where such na.,.,., ' ' ~y masking
vapor blanket may be formed by at l~ast one of nitro~en, carbon
--6-
WO 94/28196 ~ ~ ~ 3 3 5 ~ PCT/US94/06004
dioxide, perflu~, u~,al u~ll, hydrofiu~, UCal uv~. or hyd, ocl Il~Ocal ~on.
- In one errlho~ "~"L, the cleaning can be done in a system
where a solution of the hyd,vca,L,OIl solvent and the fluoloca,Lon
solvent is mixed together optionally with a surfactânt as a sol~l' " ,9
agent in a degreaser. The fluO~ucalL~on~ being more volatile, provides
a rla""" ' "~y SU,u~u~t~aa;OIl blanket. The same flu~lu.,alLùll would be
us~d in the adjacent rinse sump for an initial illl~t l aiv~ or spray liquid
rinse followed by a final rinse in the vapor.
In the simplest ~ L~ L, the cleaning can be done in a one
sump system where a solution of the l~Jtu-,a~Lùn solvent and the
lower boiling fluO~uca~uù~ solven~ is mixed together optionally with a
surfactant as a ' ' " ,9 agent. The fluo(u~ Lon, being more
volatile, provides a rla~ y su~,u~ 1 blanket, and if the soiled
part which has been immersed in the cleaning mixture is held in the
cond~ai~g fluO,u~.a~uo,l vapors for a sufficiently long period of time,
the part can be removed from the vapor phase clean and is dry.
The term htd~uca,l,on solvent" as used herein means any
solvent which has at least one hydrogen atom and at least one carbon
3~0m.
The organic cleanin~ solvent can be selected from linear or
branched alkyl or alkanol ,~ùnoca~LG,~ i or ." u~ esters having
at least one carbon atom in the ester moiety and such solvent most
,f~.,dLly having a flash point greater then 200F(93C~, or less
~,fl,,.l~ly having a flash point greater than 150F(66C~. Useful
ssters include methyl ester and a mixture of the dimethyl esters of
adipic acid, succinic acid, and glutaric acid. The organic fluid may
also be selected from linear or cyclic I~,~d~ u.~al~u~s c~ 9 at least
one ol~finic bond endo or exo to the ring.
The l.~rd~u~,alLu~ cleaning agent may comprise pinene and/or
WO 94/28196 PCT/US94/06004
~ b3~i
ca".~.he,~e, or may comprise terpinene, limonene, terpinolene,
terpineol, linaleol, and other related members of the terpene family.
10 ~ ~ ~
ALPHA - PI~131iE E~A - P~ CA~P}D3NE
ALPHI~ RPIN13N~ L~ ~ R~
, ~3 $1 \~U
ALP~A-TERPIN13OL WL~I~OL 2!ENTHOL
-8--
wo 94/28196 ~ 1 ti 3 3 ~ I PCT/US94/06004
The organic cleaning solvent may also consist of linear,
branched or cyclic hydrocarbons c~r,L~ ;"g C,0 to C30 species.
The organic cleaning fluid may also consist of hyvloca,~on
cu"i , ,9 olefinic moieties which have been substituted with R1-RI2
-~ s groups, wherein 1-2 hydrogen atoms or alkyl groups containing 1-6
carbon atoms or both may comprise the substituted group, i.e.,
Rl R2
R1~3 4
'I`\ /~ R5
Rlo ~\ R6
Rg R7
A useful exâmple includes 1,5- " ,~,tl.~lc~ e.
This orgânic Cleâning fluid may âlso be cv~ is~d of acyclic or
cvclic monols or diols defined by the lineâr structure (1 )
R(CH2~nOH ( 1 )
R = H, hydroxyl
where n is selected from 1 to 20
g
~ 33~
WO 94/28196 PCT/US94/06004
or the branched structure (2)
R,
5 R2-C-(CH2)nOH (2)
Rl
where n is selected from 1 to 20
or the cyclic structure (3)
o~
~ ~ 9
R5 R6
(3)
wh~re R1-RD is defined as alkyl or hydro~en groups or mixtures thereof,
and n is defined as 0 to 6. Useful diois includ~ c~ GA~ I and
pol~.th~l~i.,6 ~31ycol (MW 200) (a polyether diol).
The or~anic fluid may also bs cu."~ ad of linearr branched, or
2S cyclic mono or polyl ~ , such as
-10-
WO 94/28196 PCT/US94/06004
~1633~ .
o
Rg ~J~R12 ~ n
R77~ ~4
R8 / \ R3
R5 R6
where n is defined as O to 6 and R1-Rto is defined as alkyl or hydrogen
10 groups or mixtur~s thereof. A useful cyclic ketone include
cy~ a~ lld.
Other orsanic cleaning fluids l", ' ' ' to this invention may be
c~""~ris~d of:
(a~ alkyl or aryl nitriles of the formula
R- CN
where R may be an alkyl ~roup (methyl, ethyl. etCl, a phenyl group, or
an alkyl substituted phenyl ~roup
(b) an 'kyl~a.. ,~ of the formula
Rl
[~
-11-
Wo 94/28196 .,~ ~ ~ 3 3 ~1 PCT/US94/06004
(c) alkvl esters such as diethyl,uhLllalaL~ of the formula:
C02Rl
CO 2 R2
(d) polyether alkanols of the formula:
Rz
Rl-~CHCHzO)nH
where R, is chosen from the class of compounds defined by H, alkyl,
or hydroxyl groups and Rz is selected from the class of compounds
20 defined Dy H or alky~ or fluoroalkyl groups.
-12-
WO 94128196 ~ ~ ~ 3 ~ ~ ~ PCTIUS94106004
(e) substituted aromatics of the formula:
.. . .
R
1~ R~A~
R5
R4
where R,-R~, is chosen from hydrogen, alkyl, fluoroalkyl, or halogen
15 groups and c~,..' .aliùns thereof, such as trifluu.uL~.~.J.~e.
Such organic cleaning solvent may also comprise mixtures of all
the above organic cleaning solYents with flu~, u~,al uons such as linear,
branched, or cyclic perfluu~u.,a,Lùl~s or hydroflu~,uc.l.Lu..~ or
h1d~u~l~lc urlu~lu~,alLùnsoptionally with substituted oxygen, sulfur,
ni~rogen,p~ûs~,h~,ous or other halogen atoms attached to a carbon
atom and optionally with. surfactant as a ~ agent.
The fluO~u~.a~Lu~ rinse solvent may be selected from the class
of hydrofluu~u~a~Lùn or l.~J~ùcl.'~ urlu~ocalLùn compounds or
rnixtures c~ .d of linear, branched, or cyclic structures having a
boiling point of at least 25C to 120C and such flu~.u~,a.Lùns may
be optionally s~hstit~t~d with other functional groups chosen from the
class co~ .ti.,~ of other halogens and oxygen, sulfur, nitrogen, and
pl Iû~Jl u~ uus atoms
The preferred hydroflu~, ucal Lùl, compounds or the
-13-
WO 94/28196 ~ PCT/US94106004
h~dlu~,lllolu~l~orùcal uOn compounds have a eertain miseibility for the
organie eleaning solvents in the boiling range of at least 25C to
1 20C so that at least 2 mole % of the hydroearbon cleaning solvent
is miscible with the hydrofluoru~al uol- fluid without obtaining phase
S Sl:pal a Lion .
The hydroflu~.oca. Lons praferably contain between 3 to 8
carbon atoms, hydrogen, and fluorine in the eompound. The boiling
point is p-u~u-c.uly between 25C and 120C with at least 60 weight
pereent fluorine. The compounds ~lu~ulauly have a linear or branched
10 chain.
The present invention provides a Culll,uOailiOI~ for eleaning or
removing residual soils or surfaee C~lllal.. .aliùn from a part. The
CulllpOailiOI~ col~nie~ a non-~L~.L,upi~ mixture of ll~ul,alb
solvent and hydroflu~ru~alL~n solvent. The h~1dlucaluùl~ c~""~one"~
15 is present in an amount of at least 2 weight pûreent based on the total
COlll,uuailiùn and is eapable of suL~ y removing the residual soils
or surfaee culllalllillaliùn from the part. Th~ hydroflu~,ùca,~on
cu""~on_..l has a linear or branehed ehain strueture havirlg 3 to 7
earbon atoms and at least 6û wei0ht pereent fluorine, is eapable of
20 subalalli' 'ly removing any of the l.~J~ùca,L~n cu,u~ ll remaining
on the part, and is less eapable than the ll~ùcalLull Cu~pO~ l of
subalall~ removing the residual soils or surfaee Culllalllillaliùn from
the part.
In eontrast to the eleaning ~ -s of
European Patent Publieation 431,458 published June 12, 1991
wherein an aliphatie l~tdl~ ùcc,~Lùn is the "aetive" cu".~-or~,.,l for
the removal of the fluxes, fats and oils, and dust, the ~ dlu~.alL
co."~,~n~..l of the present eleaning cu,,.~ ~5 is eapable of
suLala..i '~y ramoving the residual soils or surfaee eG..Ia."i,.alion from
-14-
WO 94/28196 PCT/US94/06004
~1~33~ ~
a part. The hydrofluoruca,Lo" coi,,u~llellt of the present cleaning
.o""uo~;lions has excellent solvency ~llelld~ iCS toward the
hy~,ùccl,~ùn co""~u"~"l but has a lesser solvency than the
hyd,uca,Lon co"~ "L for the soils or surface c~"l~",;".,Liol~.
Providing tlallllll ' "Iy SUpp~t:,Siùl~ can be ", ,i ,e~ through
the use of suitable vapor blanketing species. The rinse solvent may
also be selected from compounds or mlxtures c~"",,;s~d of other
linear, branched, or cyclic alkyl or aryl alcohols, esters, nitro-,
nitrocyclo-, or nitrile compounds, ethers, ketones, hy~ucc~Lûlls, and
other non-aqueous media.
Still other objects and ~dvallla~cs of the present invantion will
become readily apparent to those skilled in this art from th~ following
detailed cla~_,i,ullon, wherein only th~ preferred _,"LA " "~ L~ of the
invantlon are shown and describsd, simply by way of illustration of
tha best mode c~llt~.ll,ul~lt~.d of carrying out the invention. As will be
realized, the invention is capable of other and different 6,1,L " ll~llb,
and its several details are capable of ~ o~7s in various obvious
respects, all without departing from the invention. Acco~d;l,yly, the
drawing and d~s.,li,.,lion are to be regarded as illustrative in nature,
and not as 1l : i-.t;./~.
Bri~7f Des~ -7 of Drawinas
Figure 1 is a partial s~,ll .n~Lic view of del~ or defluxing
en~ that may be used in tl7e multi-solvent non-aqueous cleaning
system of the present ill~l~,. n;
Figure 2 is a ~..11 lldt;~. view depicting an dltu.ll~th/~
C.l L ~ .,l of eq~ _.,l that may be used in the present invention;
Figure 3 is a s~ .llali-, view depicting a further ': llaLhe,
.,.IIL- " 11_.11 of e71, 1 .,l for use in the present invention;
WO 94128196 ~ j 3 3~ ~ PCTIIJS94/06004
Figure 4 is a partial schematic view of yet further a~ternative
equipment for practicing the system of the present invention;
Figure 5 is another ~IllLou;",~"~ of qq~i",e"l for use in the
present invention; and
Figure 6 is a further el"L-~ "t "I of eq~ i"~"L for use in the
present invention.
Best Mode for Carrving out the Invention
In its most basic form, the present invention is a novel non-
aqueous cleaning process wherebv the most attractive features of the
semi-aqueous cleanin~ process and the solvent vapor d~y,aas;~,g
solvent procâss are combined. ~ - - ' - ''y, a substrate or part to be
cleaned (e.g., a printed circuit board coated with a rosin-based flux, or
a metallic or n~ "ic part coated with a petroleum, synthetic, or
semi-synthetic based oil or grease) is first washed in a warm or
ambient temperature 1~ ~rd~ u~,al Lol~ solvent tending to have a ~reater
affinity for the soil or ~u,l~all.;..a.ll on the substrate than a
fluo~o.,a.Lùn based solvent. The pârt is then rinsed by spray or
i~lllll~.aiùn in a second tank or cleaning region c~"~ a
20 n~l,rla""" ' ' flur.,u~.a,l,ùn solvent, ,GI. c~ aLly having a lower boiling
point than the I ., ~: u~,a- Lu. . solvent. The flu~. u~.a- Lu. . solvent has atleast sliqht wlubility for the ~d~o~,a~Lùn solvent and therefors rinses
the l,,d~ù.,a,Lùn solvent from the surface of the part. The
fluu~ Lu~ solvent is then dried from the part surface by u~à~<JIali
25 in a known manner. The benefit of this process is that drying costs
are ",, "i.a~, waste water treatrnent costs and eq~ i, lla~ll and capital
ill;. ~II~.lLa are virtually -' Ilillal-.d, and safety of operation is
improved. Further, through the use of hydroflu~, u~,al Lùn or
perflu~,u~.a,uù~ solvents in the rinse and drying steps, the
wo 94/28l96 PCT/US94/06004
~l 633~1
em,;.un",~:"~dl benefit is greatly improved over the chlorocarbon or
chloroflu~,uca,Lon solvent systems.
" The organic c!eaning agent is pl~ralaLI~ a hydrocarbon which
may be selected from linear or branched alkyl or alkanol
IllOl~ocaluoxylic esters having at least six carbon atoms in the aliphatic
moiety and at least one carbon atom in the ester moiety.
The organic ll~ u~,aluùl~ fluid may also be selected from linear
or cyclic h~ i~oca,l-ons cu~ ,9 at least one olefinic bond endo or
exo to the ring.
The ~ uca~LOI~ may also be pinene and/or c.alllpll_.~e.
The preferrâd hydrofluu, u~al uù"s include compounds of the
empiricâl formuia:
CJHnF"n where 1 < n < 4
The three carbon hydroflu~luoalboll~ include tetrafluo(u~,upalles
(HFC-254), pentaflu~lo,c~upd.. os (HFC-245), hexaflu~.u,u-u~,a.. as (HFC-236), and heptafluo,op(upa,,~ (HFC-Z27). Preferred three carbon
hydrofluon,. a, I,uns include tetraflu~, u,u, u~Jal laa and
pentafh,o(u~panes. Tetrafluo.up(u~,a..~ include the following
isomers:
HFC-254 isomers
CFH2CF2CFH2
CF2HCF2CH,
CF2HCHFCFH2
CF,CHFCH3
- CF2HCH2CF2H
CF3CH2CFH2
-17-
WO 94/28196 ~ 3~ PCT/U594/06004
Pentafl~u,op,ùpo,,es include the fo~lûwing isomers:
HFC-245 isomers
CF2HCF2CFH2
CF3CF2CH3
CF2HCHFCF2H
CF3CHFCFH2
CF3CH2CHF2
Thr~ preferred hydrofluoru. a,L.ons include linear or branched
compounds of the ~mpirical formula:
C~HnFlo.n wh~re 1 < n < 5
15 Th~ four carbon hydroflu~,uu~.,Lùns inciude pentafiuorobutanes (HFC-
365), hexafluorobutanes (HFC-356), hepufluorobutanes (HFC-347),
octaflyorobutanes ~HFC-338), and nonafluorobutanes (HFC-329).
P~ntafluorobutanes includ~ the following isomers:
HFC-365
CHlCFICHF2)CHF2
Hexafluorobuunes include the following isomers:
HFC-356
CFICH2CH2CFa
CF3CHFCH2CHF2
CFaCH2CHFCHF2
CFaCF2CH2CH2F
-1~ -
Wo94/28196 2~B~ PCT/US94/06004
CF3CHFCHFCH2F
CF3CH2CF2CH2F
" CHFZCH2CF2CHF2
CHF2CHFCHFCHF2
CFH2CF2CHFCH2F
CHF2CHFCF2CHzF
CH2FCF2CF2CH2F
CHF2CF2CF2CH3
CF3CF2CHFCH3
CF3CHFCF2CH3
Heptafluorobutanes include the following isomers:
HFC-347
CH3CF2CF2CF3
CH2FCHFCF2CF3
CH2FCF2CHFCF3
CF2HCH2CF2CF3
CF2HCHFCHFCF3
CF3CH2CHFCF3
CH2FCF2CF2CF2H
CF2HCHFCFICF2H
-19-
wo 94/25196 2~L633 PCT/US94106004
Octafluorobutanes include the foiiowing isomers:
HFC-338
CF3CHFCHFCF3
(CF3)2CHCHF2
CF3CF2CF2CH2F
CF3CF2CHFCHF2
CF3CHFCF2CHF2
CF3CF2CH2CHF2
CHF2CF2CF2CHF2
Nonafluorobutanes include the following isomers:
HFC-329
CF2HCF2CF2CF3
CFJCHFCF2CF3
The preferred hydroflu~. uc~ s include linear or branched
compounds of the empirical formula:
Cs Hn F12A wherè 1 < n < 6
The five carbon hydroflu~.u.,t..uùl~s include hexafluû~p .~ HFC
476), hePtafl~ U~U~ a~5 (HFC-467), octaflu~.up~ i (HFC-458~,
nonflu~.~u,u~ i (HFC-449), decaflu~up~ (HFC-43 10), and
undecafluu.u~.~..l....~i (HFC-42~ IU~U~ include the
3 o following isomers:
-20 -
WO 94128196 ~ ~ ~ 3 3 ~ ~ PCT/US94/06004
HFC-467
CH2FCH2CF2CF2CHF2
- CH2FCF2CF2CH2CHF2
CH2FCF2CH2CF2CHF2
5 CH2FCHFCHFCF2CHF2
CH2FCHFCF2CHFCHF2
CH2FCF2CHFCHFCHF2
CHF2CF2CF2CHFCH,
CHF2CF2CHFCF2CH3
10 CHF2CHFCF2CF2CH3
CHF2CF2CHFCH2CHF2
CHF2CHFCF2CH2CHF2
CHF2CF2CH2CHFCHF2
CHF2CHFCHFCHFCHF2
15 CH2FCHFCF2CF2CH2F
CH2FCF2CHFCF2CH2F
CF3CF2CF2CH2CH3
CF3CF2CH2CF2CH3
CF ,CF2CHFCHFCH3
2 0 CF3CH2CF2CF2CH,
CH3CHFCF2CHFCH
CF3CHFCHFCF2CH3
CF3CF2CHFCH2CH2F
CF3CF2CH2CHFCH2F
25 CFJCHFCF2CH2CH2F
CF3CHFCH2CF2CH2F
-21-
WO 941~8196 '~,~633 PCT/US94/06004
CF3CH2CF2CHFCH2F
CF3CH2CHFCFzCHzF
CF3CHFCHFCHFCH2F
CF3CF2CH2CH2CHF2
CF3CH2CH2CF2CHF2
CF3CH2CF2CH2CHF2
CF3CHFCHFCH2CHF2
CF3CHFCH2CHFCHF2
CF3CH2CHFCHFCHF2
CF3CH2CH2CHFCF3
CF3CH2CHFCH2CF3
CH 2FCF2CF2CF2CH3
CH3CF(CHFCHF2)CF3
Octafluo~o~o~ inciude the ~ollowing isom~rs:
HFC-458
2 0 CH3CFHCF2CF2CF3
CH3CF2CFHCF2CF3
CH3CF2CF2CFHCF3
CH2FCHzCF2CF2CF3
CH2FCHFCHFCF2CF3
CH2FCHFCF2CHFCF3
CH2FCF2CH2CF2CF3
CH2FCF2CHFCHFCF3
CH2FCF2CF2CH2CF3
-22 -
WO 941~8196 PCT/US94/06004
~1~33~1
CF2HCH2CHFCF2CF3
CF2HCH2CF2CHFCF3
~' CF2HCFHCH2CF2CF3
CF2HCHFCHFCHFCF3
5 CF2HCHFCF2CH2CF3
CF2HCF2CH2CFHCF3
CF2HCF2CHFCH2CF3
CF3CH2CH2CF2CF3
CF3CH2CHFCHFCF3
10 CF3CH2CF2CH2CF3
CF3CHFCH2CHFCF3
CH2FCF2CHFCF2CF2H
CH2FCF2CF2CHFCF2H
CH3CF2CFzCF2CF2H
s CF2HCH2CF2CF2CF2H
CF2HCHFCHFCF2CF2H
CF2HCHFCF2CHFCF2H
CF2HCF2CH2CF2CF2H
CH2FCF2CF2CF2CH2F
20 CH3CH(CF2CF,)CFI
A most preferred octaflu~,u~ is CF3CH2CF2CH2CF3
which is known in the art as HFC-458 mfcf.
-23 -
wO 9412~196 ~ 335~ PCT/US94/06004
Nonafluoru~ lles include the following isomers:
HFC-449
CF3CF,CHFCH2CF3
CF3CHzCF2CHFCF3 `
CF3CHFCH2CF2CF3
CF3CHFCHFCHFCF3
CF3CH2CF2CF2CHFz
CF3CHFCHFCF,CHF2
CF3CF2CH2CF2CHF2
CF3CHFCF2CHFCHF2
CF3CF2CHFCHFCHF2
CFJCF2CF2CH2CHF2
CF3CF2CF2CHFCH2F
CF3CF2CHFCF2CH2F
CF,CHFCF2CF2CH2F
CF3CF2CF2CF2CH3
CHF2CF2CF2CHFCHF2
CHF2CF2CHFCF2CHF2
CHF2CF2CF2CF2CH2F
CHF2CH(CHF2)CF2CF3
-24-
WO 94128196 PCTIUS94/06004
~i &~
Decafluo,opt~ dl~es include the following isomers:
H FC-43- 10
CHzFCF2CF2CFzCF3
CF2HCHFCF2CF2CF3
CF2HCF2CHFCF2CF3
CF2HCF2CF2CHFCF3
CF3CH2CF2CF2CF3
CF3CF2CHFCHFCF3
CF3CHFCF2CHFCF3
CF3cF2cH2cF2cF3
CF2HCF2CF2CF2CF2H
CHF2CF~CHF2)CF2CF3
U~d-dcafluorùp~d.,l~"~s includ~ the following isomers: ~
HFC-42-1 1
2 o CF3CF2CF2CF2CF2H
CF3CF2CF2CFHCF,
CF3CF2CFHCF2CF,
CHF2CF2CF(CF3~2
The preferrod hydroflu<;,u~,a,Lu,,, include linear or branched
compounds of the empirical formula:
C"HnFl~n where 1 < n < 7
The six carbon hydroflu~, u~al L~ls include heptafluo-ul l_ACII l'dS (HFC-
587), octafluo,~o~ Aa.,~ (HFC-578~, nonafluo~ Aal~c~ (I IFC-569),
-25 -
WO 94/28196 2~6335~ PCT/US94106004
decafluorop~llal~es ~HFC-55-10), undecafluorohexanes (HFC-5~11),
dodecafluo(ol-exa"es (HFC-53-12~, and tridecafluo,uh~a,~es (HFC-52-
13). ` .
Heptafluo,~,h6Aàl~es include the following isomers: -
HFC-587
CH3CH2CH2CF2CF2CF3
CH3CH2CFHCFHCF2CF3
CH3CH(CHFCH2CF3)CF3
Octâflu~lOl~e,~al,~ include the followin~ isomers:
HFC-578
CH3CHFCF2CHFCHFCF3
CH2FCHFCH2CFzCHFCF3
CF2HCHFCF2CF2CHFCF2H
CF3CF2CH2CH2CF2CF3
CH3CF~CF2H)CHFCHFCF3
CH3CF2CF(CF3)CF2CH3
Nonafluu,vl.~ a,~ includ~ the following isomers:
HFC-569
CF3CH2CH2CHFCF2CF3
CF3CH2CH2CF2CHFCF,
CF3CFzCH2CHFCH2CFJ
CFlCHFCHFCHFCHzCF3
CF3CHzCFzCHFCH2CF3
-26-
WO 94128196 PCT/U594/06004
~ 633~1
CF3CHFCHzCF2CH2CF3
CF3CHFCH2CH2CF2CF3
CF3CHFCHFCH2CHFCF3
ICF3CH2)2CHCF3
CF3CF2CF2CH2CH2CHF2
CF3CF2CHFCHFCH2CHF2
CF3CHFCF2CHFCH2CHF2
CF3CF2CH2CF2CH2CHF2
CF3CHFCHFCF2CH2CHF2
10 CF3CH2CF2CF2CH2CHF2
CF3CF2CHFCH2CHFCHF2
CF3CHFCF2CH2CHFCHF2
CF3CF2CH2CHFCHFCHF2
CF3CHFCHFCHFCHFCHF2
15 CF3CH2CF2CHFCHFcHF2
CF3CF2CF2CHFCH2CH2F
CF3CF2CHFCF2CH2CH2F
CF3CHFCF2CF2CH2CH2F
CF3CF2CF2CH2CHFCH2F
20 CF,CF2CHFCHFCHFCH2F
CF,CHFCF2CHFCHFCH2F
CF,CF2CH2CF2CHFCH2F
CH3CF~CF,)CHFCHFCF,
CHF2CF2CF2CHFCH2CHF2
25 CHF2CF2CHFCF2CH2CHF2
CHF2CHFCF2CF2CH2CHF2
CF,CF2CHFCH2CHFCHF2
WO 94/:Z8196 ~ ~33~ PCTIUS94/06004
CHF2CF2CHFCHFCHFCHF2
CHF2CHFCF2CHFCHFcHF2
CHF2CF2CH2CF2CHFCHF2
CHF2CF2CHFCH2CF2cHF2
CHF2CF2CF2CF2CH2CH2F
CHF2CF2CF2CHFCHFCH2F
CHF2CF2CHFCF2CHFCH2F
CHF2CHFCF2CF2CHFCH2F
CHF2CF2CF2CH2CF2CH2F
CHF2CF2CHFCHFCF2CH2F
CHF2CHFCF2CHFCF2CH2F
CHF2CF2CH2CF2CF2CH2F
CHF2CHFCHFCF2CF2CH2F
CHF2CH2CF2CF2CF2CH2F
CF2HCF2CF2CF2CHFCH3
CF2HCF2CF2CHFCF2CH3
CHF2CF2CHFCF2CF2CH3
CHF2CHFCF2CF2CF2CH3
CH2FCF2CF2CF2CF2CH,
CH2FCF2CF2CF2CHFCH2F
CH2FCF2CF2CHFCF2CH2F
CF3CHFCHFCF2CHFCH2F
CF3CH2CF2CF2CHFCH2F
CF3CF2CHFCH2CF2CH2F
CF3CHFCF2CH2CF2CH2F
CF3CF2CH2CHFCF2CH2F
CF3CHFCHFCHFCF2CH2F
-28 -
WO 94/28196 ~ 1 6 3 3 ~ ~ PCT/US94/06004
CF3CH2CF2CFHCF2CH2F
CF3CHFCH2CF2CF2CH2F
CF3CH 2CHFCF2CF2CH2F
CF3CHFCH2CF2CHFCHF2
5 CF3CH2CHFCF2CHFCHF2
CF3CF2CH2CH2CF2cHF2
CF3CHFCHFCH2CF2cHF2
CF3CH2CF2CH2CF2cHF2
CF3CHFCH2CHFCF2CHF2
10 CF3CH2CH2CF2CF2CHF2
CF3CH2CHFCHFCF2CHF2
CF3CFzCF2CF2CH2CH3
CF3CF2CF2CHFCHFCH3
CF3CF2CHFCH2CHFCH3
15 CF3CHFCFzCFzCHFCH3
'`' ' CF3CF2CF2CH2CF2CH3
CF3CF2CHFCHFCF2CH3
CF3CHFCF2CHFCF2CH3
CF3CF2CH2CF2CF2CH3
20 CF3CHFCHFCF2CF2CH3
CF,CH2CF2CF2CF2CH3
Decaflu~.,u~e.,l...,~s include the following isomers:
25 HFC-55-10
CF3CF2CF2CH2CH2CF3
CF3CF2CHFCHFCH2CF3
-29 -
WO 94/28196 PCT/US94/06004
~6~
CF3CHFCF2CHFCH2CF3
CF3CF2CH2CF2CH3CF3
CF3CHFCHFCF2CH2CF3
CF3CH2CF2CF2CH2CF3 ;,
5 CF3CHFCH2CHFCF2CF3
CF3CHFCH2CF2CHFCF3
CF3CHFCHFCH2CF2CF3
CF3CHFCHFCHFCHFCF3
CF3CF2CH2CH2CF2CF3
CF3CF2CF2CHFCH2cHF2
CF3CF2CHFCF2CH2CHF2
CF3CHFCF2CF2CHFcHF2
CF2CF2CF2CH2CHFCHF2
CF3CF2CHFCHFCHFCHF2
CFsCHFCF2CHFCHFCHF2
CF3CF2CH2CF2CHFCHF2
CF3CHFCHFCF2CHFCHF2
CF3CH2CF2CF2CHFCHF2
CF3CF2CHFCH2CF2CHF2
CF3CHFCF2CH2CF2CHF2
CF3CF2CH2CHFCF2CHF2
CF3CHFCHFCHFCF2CHF2
CF3CH2CF2CHFCF2CHF2
CF3CHFCH2CF2CF2CHF2
CF3CH2CHFCF2CF2CHF2
-30 -
.
WO 94/28196 ~ ~ & 3 3 ~ ~ PCT/US94/06004
CF3CFzCF2CF2CH2CH2F
CF3CF2CF2CHFCHFCH2F
- CFICF2CHFCF2CHFCH2F
CF3CHFCF2CF2CHFCH2F
5 CF3CF2CF2CH2CF2CH2F
CF3CF2CHFCHFCF2CH2F
CF3CHFCF2CHFCF2CH2F
CF3CF2CH2CF2CF2CH2F
CF3CHFCHFCF2CF2CH2F
CHF2CF2CHFCF2CF2CH2F
CF,CF2CF2CF2CHFCH3
CF3CF2CF2CHFCF2CH3
CF3CF2CHFCF2CF2CH3
CF3CHFCF2CF2CF2CH3
CHF2CF2CF2CHFCHFCHF2
CHF2CF2CHFCF2CHFCHF2
CHF2CHFCF2CF2CHFCHF2
CHF2CF2CF2CH2CF2CHF2
CHF2CF2CHFCHFCF2cHF2
CHF2CF2CF2CF2CF2CHF2
CHF2CF2CF2CF2CHIFCH2F
CHF2CF2CF2CHFCF2CH2F
CHF2CF2CHFCF2CF2CH2F
CHF2CHFCF2CF2CF2CH2F
CH2FCF2CF2CF2CF2CH2F
CHF2CF2CF2CF2CF2CH3
CFICF2CF2CF2CHFCH3
-31-
WO 94/~8196 S~ PCT/US94106004
CF3CF2CF2CHFCF2CH3
CF3CF2CHFCF2CF2CH3
CF3CHFCF2CF2CF2CH3 '.
S
UndecafluorolleAd,les include ~he following isomers:
HFC-5~1 1
CH3(CF2)4CF3
CH3CF(CF3)CF2CF2CF3
(CF3)2CHCH2CF2CF3
CH2FCHF(CF2)3CF3
CH2FCF2CHFCFzCF2CF3
CH2FCF2CF2CHFCF2CF3
CH2F(CF2)3CHFCF3
CF2HcH2(cF2)3cF3
CF2HCHFCHFCF2CF2CF3
CF2HCHFCF2CHFCF2CF,
CF2HCHFCF2CF2CHFCF3
2 0 CF2HCF2CH2CF2CF2CF3
CF2HCF2CHFCHFCF2CF3
CF2HCF2CHFCF2CHFCF3
CF2HCF2CF2CH2CF2CF3
CF2HCF2CF2CHFCHFCF3
CF2H(CF2)3CH2CF3
CF3CH2CHFCF2CF2CF3
CF3CH2CF2CHFCF2CF3
CF3CHFCF2CF2CH2CF3
Wo 94/28196 PCT/US94/06004
CF3CF2CF2CH2CHFCF3
CF3CHFCHFCHFCF2CF3
' CF3CHFCF2CHFCHFCF3
CF3CHFCF2CH2CF2CFJ
CF3CF2CH2CHFCF2CF3
CH2F(CF2~"CF2H
CF2HCHF(CF2)3CF2H
CF2HCF2CHFCF2CF2CF2H
A preferred undecaflu~,uh~,~a"~ is
(CF3)2CHCH2CFzCF, which is known in the art as
HFC-5~11 mmzf. Dod~cafluû~o~,~Aa,,~include
the following isomers:
HFC-53-12
CF3CFzCHFCHFCF2CF3
CF3CFzCF2CH2CF2CF3
CF3CHFCF2CF2CHFCF3
CF3CF2CHFCFzCHFCF3
CF3CHFCHFCF2CF2CF3
CF3CF2CF2CF2CH2CF3
CF3CF2CF2CF2CHFCHF2
CF3CF2CF2CHFCF2CHF2
CF3CF2CHFCF2CF2CHF2
CF3CHFCF2CF2CF2CHF2
CF3CF2CF2CF2CF2CH2F
CF2HCF2CF2CF2CF2cHF2
-33 -
.
wo 94/28196 2 ~ 6 3 3 51 PCT/US94/06004
CHF2CF2CH(CF3)CF2CF3
(CF3~2CHCFHCF2CF3
A preferred dodecafluorohexane is
5 (CF3)2CHCHFCF2CF3 which is known in the art as
HFC-53-12 mmze~ Tridecaflu~,uh~,~a~es include the
following isomers:
HFC-52-1 3
CF2HCF2CF2CF2CF2CF3
CF3CHFCF2CF2CF2CF3
CF3CF2CHFCF2CF2CF3
CHF2CF2CF(CF3)CF2CF3
Other preferred l~ldlu'' ~o,u-....l,o"s include linear or
branched compounds of the empirical formula:
C,HnF where 1 c n 5 8~
2~ ne"~ L~Li~ xamples of this class are:
CH3CH2CH2CHFCF2CF2CF3
CH3CHFCH2CF2CHFCF2CF3
CH3(CF215CH3
CH3CH2(CF2)"CF3
CF3CH2CH2(CF2)3CF3
CH2FCF2CHF(CF2)3CF3
CF3CF2CF2CHFCHFCF2CF
CF3CF2CF2CHFCF2CF2CF3
CH,CH2CH2CHFCF(CF3)2
-34-
WO 94~28196 ~ ~ 6 3 3 51 PCT/IJS94/06004
CH3CH(CF3)CF2CF2CF2CH3
- CH3CF(CF3)CH2CFHCF2CF3
CH3CF(CF2CF3)CHFCF2CF
CH,CH2CH (CF3)CF2CF2CF3
- 5 CHF2CF(CF3) (CF2)3CHF2
CHF2CF(CF3)(CF2)3CF3
Other preferred hydrofluo(uca.bùns include linear or branched
compounds of the empirical formula
C8HnF where 1 < n s 9.
Re~ us~ th/~ examples of this class are:
CH3CH2CH2CH2CF2CF2CF2CF3
CH3~CF2)~CH3
HCF2(CF2~CF2H
CF3(CF21~sCF2H
CHF2CF(CF3)(CF2~,.CF3
CH,CH2CH(CFI)CF2CF2CF2CF2
CH3CF(CF2CF3)CHFCF2CF2CF3
CH3CH2CH2CHFC(CF3)2CF3
CH3C(CF3)2CF2CF2CF2CH3
CH3CH2CH2CF(CF3)CF(cF3)2
CH2FCF2CF2CHF(CF2)3CF3
The hydrofluu,u.,a.Lùn cc,,..pùn6..L may also be an a~ul~u~
mixture of hydrofl-,o,uca,L~n and another cu.l.~Jùl~ L as long as the
mixture is capable of suLalall 'Iy removin~ any
- 25 ~ uca~L~ co...pon_.,l remainin~ on the part and is less capable
than the l~t91u~.~lLùl~ -",un_..l of ~ removing the
residual soils or surface COIIlal.l Idt;.a.~ from the part. Examples of
preferred d~Jll" mixtures include CF3CH2CF2CH2CF3 and one of
the followin~ c~ ull_.ll~. methanol, ethanol, ;su~JIu~a~lul, n-
-35-
WO 94~28196 PCT/US94106004
21~33~1
propanol, t-butanol, isobutanol, n-butanol, t-amyl alcohol,
u, u~ lene, and p~, ~l ,lo- o~ ll ,ylene.
Figure 1 is a partial s.llt~lllali., illustration of one type of ~.
apparatus which can be used in the present process. Therein, a
vessel (10) is divided into three sumps: a cleaning sump 15, a wash
sump 20, and a rinsing sump 25. The cleaning c~lll,ualllll~lll 15 is
separated by one or more walls 17,19 from the second
COIll,ual ~ 11l 20, which contains a flu~.ùcaluon fluid 22 heated to
its boiling point by a heater 34, to provide a r.ul.rla..ll.laL,l_
10 condarlsi"g vapor blanket 30 or a flallllll ' ~ Su,u~ aiul~ blanket
over all the sumps 15, 20, 25 common to vessel 10. C~..l,uallllle~
20 also provides an area where the bulk of the soil and organic
cleaning agent can be washed from the substrate by either
illll~l~.aill~ into the fluofoca.uùn fluid contained in cu~llual ll.lt,.ll 20
15 or by ,c la~ . l lv. l l in a spray stream 18 of pure fluo~ocal Lùn
colldf rl .a~t" whereby the Cul~t....l I ~ ~ liquid drops into the sump
below. The clsaning Cu~,ua~ ..l 15 is adapted to contain a body
of the organic cleaning solvent 24 tailored for the cleaning
3~ iùn, which could be an organic ~ u.,a.Lon as noted above
20 and in the examples below for heavy duty cleaning. or a mixture of
an organ~c l l, J~ u.. . Lvl I with a milder solvent such as a fluul u~.al uu
for less ri~qorous cleaning ~ s ~where Cu,ll, ' ' ~y with the
substrate may be of more important co~ u~a~iùn)~ The washing
CG..~ .. t~ .ll 20 is adapted to contain a rinsin~ a~ent 22 having at
25 least sli~ht solubility for the cleaning solvent 24. As used
throughout this sr~ , "slight solubility" of the rinsing
flu~lu..alL.ull solvent for the l ,~l~. Lùl) cleaning solvent Is defined
as havlng 2 2 mole % of the ll~.' ucaluùn is soluble in flu~lucalL
solvent. An l~, up~ i t~. rinsing agent 22 and one preferred in the
36~
Wo 94/28196 ~16 3 3 ~1 PCT/US94106004
present invention is a fluo~ ucal Lon based solvent as noted above
and in the examples below. Optionally, a second rinsing
colllpal LIII~IIL 25, which is at a cooler temperature than
C~ palLllla,~ 20, may be provided dO~ a"~ from the first rinsing
5 colll~JalLIll~l~l 20, and is also adapted to contain the fluolu~all~ol~
solvent rinsing agent. The purpose of COIIl,l)a~ llL 25 is to provide
a final ;~ ..a;ùn rinse for the subsuate to remove trace residues of
soil or cleaning solvent and also to cool the substrate so that the
part is rinsed with pure condensing vapor in the vapor zone 30. The
10 vapor zone 30 is formed above the ~ ,u6~;1iie COIll,ual Llll~
15,20,25 and a cooling coil 32 of a type known in the art (such as
disclosed in U.S. Fatent 4,261,111 to Rand) defines the u,uu~,,,,u~L
extent of the vapor zone 32 to condense vapor for return of
cOl)d.3.~al~ to c~""~.., I,,,t,,,L 25.
It is to be noted that the ll~J~ùcalLùl~ cleaning solvent 24 and
fluoru~aluoll rinsing fluid 22 may be chosen for their respective
mutual ' ~ ' such that some means of physical r~"Jalaliùll such
as phase ~palaLIul- may be ~mployed to remove built-up soils as
well as to recycle clean organic solvent back to its o, ;~ ,.,Li"g sump.
20 Therefore, with reference to Figure 1, it is to be noted that a U-tub~
phase separator (not shown) or weir or skimmer may be used in
conjunction with colllpal llll_.ll 20 to separate or remove cu"d~ns~
II~J~ucall,ull which will float on top of the fluûlu~aluùnl and this
~ ~, aLiun device (not shown) may be arranged so that the excess
25 lltJlu;:alLu~l fluid will flow back to the cleaning tank 15 from the
rinsing tank 20.
The vessel 10 of Figure 1 is depicted as an open top type of
defluxer or drJu,~ _.. However, it is to be ull~..aluOd that the
vessel 10, in its 5~ L;~, forrn may also cl lal ~ , an i~-line
.
-
Wo 94/28196 21~ 3 3 51 PCTiUS94/06004
type of degreaser or defluxer wherein conveyor means (not shown)
may be used to succeOa;~ly convey the parts from the cleaning
sump 15 to the rinsing sumps 20 and 25.
In Figure 2, the organic cleaning fluid in cleaning tank 15 may
5 optionally be mixed with a fl~oror .,,uù,~ type solvent. The cleaning
fluid in this case would be warmed to a sufficlent temperature to
boll off the fluu,ùca,u~n, where the boiling point of the fluorocarbon
should be at least 10C. Iower than that of the organic l~ u~ uon
fluid. The mixture is heated with coils 33 so that the resulting vapor
10 zone 30 ;llllll~liatuly overlying the h~JIu~ L.ù,l is essentially a
flu~,u~ a,l,ùn-based l~o,~rla".... ' ' or ~lalllll ' "~y suu~.,..~.D;~n vapor
zone to minimize the possibility of explosion. The cleaning fluid
mixture may or may nût require a surfactant additive to ensure
phase l~u~l~uy~ y between the organic ll~lu~ alLul~ and the
15 flu~luualLùn solvents. The flu~lu~ alLo~ which was boiled off would
be ~ d ât a constant conc~"t aL;ù,~ in Cu~ Ja, Llll~ 15 by
either rsturning the vapor Cul~ Oa~l~ back to this Cu~llual ~",~ ~L
and/or pumping fluid from the rinse Cull~Jal L~ L(a) 20,25 back to
this sump throu~h control with a volume or level-sensing transducer
20 (not shown). In this variation of Figure 1, the boiling rinse sump 20
mây nût be necessary, or it could function purely as a second rinse
sump at any i" ". ' temperature between Cul,l~Ja. Ll~ L 15 and
cu".. Ll"~ 25. In the three-sump option where sump 20 supplies
the fluu~u~.a~Lu~ vapor tû form the n~(la~ aL.I~ blanket for vessal
25 lO, sump 20 maV be heated with heating coils 34 and heating coils
33 may not be necessary. In the two-sump option where sump 15
supplies the fhJ~Iu~.alLul~ vapor tû form the nu"rla"",. '~ blanket
30 for vessel 10, heâting coil 33 would be preferred and heating coil
34 may not be ne c ~ . In the twû-sump option where sump 15
-38-
wo 94/28196 ~ 6 3 ~ ~ ~ pcTruss4/o6oo4
supplies the fluolucalv~l~ vapor to form the nonrla~ labl~ blanket
30 for vessel 10, sump 20 may not be necessary and sump 25
would provide a c! liquid rinse ill~ aiùl~ prior to bringing the
cleaned substrate into the vapor cùlldel~aillg zone 30 for a final pure
5 colldensa la rinse.
In Figure 3, the rinse sump 20 may contain a saturated
solution of the h~1J~ucalL.OIl based cleaning fluid and the
fluv~ucalbvll based rinsing solvent. The fluids are selected so that
the hyv~uca.von phase separates at some low collc~.,l.c.tian (i.e.,
10 ~ess than 10 mole %) in the flu~,uca.Lon and floats to the top of the
more dense fluvlul,alLvl~, providing a c~---' ,y effect back into the
cleaning sump 15. The rinse sump(s) 25a or 25b may also in turn
cascade pure rinse solvent into sump 20 to maintain its level and
also to " .,_I;u,, ''~ provide a flow skimming action to sweep the
15 separated organic layer towards the boil sump 15.
In Figure 4, the boil sump 15 contains both hy~ucalvùl~ and
fiuv,u.,a~Lvn based solvents of sufficient i" ' '- ~/ to form
layered cleaning zones 15a and 15b. The avv~.lla~a6 of this
alla.,~, ,l is that the heating coil 33, which provides the
20 ~v"tla." ' ' vapor blanket for vessel 10, is now immersed in a
fluv(ucalvûll rich phase which lessens the ,~r ' ~y of dC~ C.IIal
fire if the liquid in the sump drops below its intended level.
hJIlll.,.lllula, the boiling fluvlu~,albull liquid now provides an
agitabon actbon to the top less dense organic I.1l~u~.a.Lùn phase to
25 assist in the cleaning ~.rv..,,a,~ce. As in Figure 3, the fluvlucarvù
rinse solvent and the ~l~dlu~.al Lvn cleaning solvent can be cascaded
or pumped back to their .~ _lh~.~ sumps to ensure that sump liquid
Yolumes are ., ~ed.
In Figure 5, the ll~d~u~r~bol~ cleaning zone 15 may be
-39 -
Wo 94n8196 2 ~ 6 ~ 3 ~1 - PCTNS94/06004
separated from the rinsing zones 20 and 25 by being provided within
separate structures 11 and 12. This configuration is intended to
provide the ability to retrofit conventional solvent vapor d~,Oaail,g
or defluxing batch-type eql~i"IOII~ such as ~O,ulOaonlod by vessel 12
5 in Figure 5 with the cleaning process of this invention. The carry-
over of organic solvent from vessel 11 to vessel 12 can be reduced
by Illecl,all ' devicss such as an air knife 37. Nitrogen or any
other nollrlal,,,,l ' ' culll,u,,,~s~d gas may be introducad into the
vapor zone overlying the hy.l,ul,alLon sump 15 to reduce
10 h~d~uca~bù~ rla",l,l ' "~y or the danger of explosion, as typical with
many types of c~"J_.,Iiùl~àl ssmi-aqueous (organic cleaning/aqueous
rinse) cleaning ~uuo.~:.3~5. in the fluo~ù~a~Lùn boil sump 20, the
residual ll~ u~,a~LJù~) carried over from cleaning sump 15 may bô
a~ separated out as described in Figure 1 and recycled
15 back with a pump 45 (as ~.I, "y depicted) in view of the
physical Soua~ - ~ of the two clOaning zones which would prevent
~s~- ' ,9 as in the previous u."L ' "_.~La.
In Fisure 6, it is presumed that the organic cleaning solvent in
cleanin~ sump 15 is ;~ ' ' '~ or of low miscibility with the
20 flu~,u.,a,L,ùn-based rinsins solvent in rinsing sump 25. To prevent
mixing of these solvents together and thOreby ,~
.Gull Id~ 9 the cleaned substrate, the flrst rinsing zone is
provided with a coupling solvent (such as an alkanol like butanol, or
another fluulu~ .al such as triflu~,uh..~.~nO, or any other type
25 of l.~l~uca~bOn) wherein th~ rluu,o~,a,Lùn solvent is miscible with
the coupling solvent. rJ'~fu.dl,l~, the flu~,. Lùn solvent has a
lower boiling point than either the organic cleaning solvent or the
coupling solvent. In this case, the flu~, uca~ Lu,~ in sump 25 primarily
sOrves the purpose of bla~ll~ti~lg the fla~ ' liquids in sumps 15
-40 -
WO 94128196 ~ PCT/US94/06004
and 20 with a no,lrla""l,aLI~ vapor, and the level of liquid in rinse
sump 20 which is c~"~urised primarily of coupling solvent is
" ,i ,ed by makeup with fluGluc~,uo,~ liquid from sump 25. The
substrate which has been rinsed in coupling solvent sump 20 is
5 either subjected to a final i"""~,c.ion rinse in sumps(s) 25a andlor
25b or is held in the flu~,u, a,b~n co"dr,~ .i"g vapor zone 42 for a
final rinse, which can be suitably accr.", ' h~d since the coupling
solvent is miscible with the fluo-.,c~,l,ù~ solvent.
FXAMPI F~
The following examples are used to d~."or,~L,a~ the
ad cleaning p~, ru""anc~ observed when a soiled coupon is
first immetsed in an organic cleaning solvent followed by a rinse
with a fluul u~ al solvent. In these studies, stainless steel
coupons were coated with various Cullllll~luidl petroleum, semi-
synthetic, and synthetic oils. The collllll~cial petroleum oils are
pal.,rri,~ ctraight or branched chain saturated ~ ùclLùl~a. All of
these oils are used in the ll-ut~ .ulki"~ industry for cooling and
iubricating purposes. The synthetic oils contain synthetic polymer
with additives cr,": ,9 fatty acids and amines. The semi-
synthetic oils are mixtures of the petroleum and synthetic oils. The
eleaning process used for tests to d_..,~ l. this invention
consisted of 30 second ;"~,_.s;on of a coupon in the organic
elsaning solvent followed by a 30 second ;~ _.ai~ in me
25 flu~u"ll_.~ .l solvent and a 30 seeond rinse above the liquid in the
eooling eoil zone with the co~ g vapors of the fluolu. I~ i- dl
solvent. The amount of soil on the coupon before and after cleaning
was 'et ~- I_d with a c~ .idl CO2 eo~ ,t~.., whieh measures
~o ~ u~ a,~ iJ;ty the amount of organic rasidue, e~ 3id in
-41-
WO 94/28196 I PCT/US94/06004
~33~
carbon units, on a surface. The sample of residue on the coupon i5
introduced into a combustion furnace via a sample boat, and is
combusted in oxygen ~I,,,r,a,uh~,~ at a temperature of 650C. The
resulting COz and other combustion products pass through scrubbers
to remove any i"L~, r~, i"g halogens, sulfur, nitrogen oxides and
water. The gas then passes to the r~o~ 6h~ cell which contains
an indicating solution. As the gas stream passes through the
solution CO2 is quantitativelv absorbed, and reacts with a chemical
in the solution to produce a titratable acid. An electric current is
then auLu,,,at 'ly adjusted to neutralize the solution, the total
current is i,.t~ t~,d, and the results displayed as ,,;u,uu,~,,,,s of
carbon. The sensitivity of this method is +/- 0.01 ~ uy~a~
carbon, which is one of the most sensitive methods to reproducibly
analyze carbon cu~".ùr.~ on a surface. Since all oils cleaned in
this invention are primarily organic in nature, the ~u~iLu~ y of
carbon content is an excellent way to determine with high
reproducibility and sensitivity the amount of organic soil on a
substrate.
2 0 Fy~rnDle One
A (C" to C") methyl ester is used as the organic solvent.
S~_Llu~copi~ cl~ t i~liùn indicated a small quantity of a
branched CGI~ u-~l-L. HFC 52-13 is a branched hydroflu~.ul;~.,uu.~
(C~F"H) used as the fluu.u~,~.Lon rinsing agent. The methyl ester is
effective in removing petroleum based oil from metal coupons at
room temperature, but a thin film of the methyl ester solvent
remained after the cleaning process. The oil is not abie to be
cleaned from the surface of the coupon by HFC 52-13. However,
fhO pA~c~S~ of clooning Wifh tho m thyl o~lcr, rin~in~ wi h HFC 5:!-
* wo 94n8l96 ~ ~ 6 3 3 ~i 1 PCT/~JS94/06004
13 followed by a rinse by the fluo-uca~on condel,~i"g vapors was
highly effective in removing greater than 99.g% of the thin film of
high boiling ester from the metal coupon without leaving a
measurable trace of oil C~llL~ .lalll. Effectiveness of cleaning was
5 assessed by weight measurements. In each of the examples below,
blank coupons were d.~l~lllli.l6d to contain about 10 ug carbon on
tha surface.
FY~rnDle Two
A dibasic ester cieâning solvent mixture was prepared in the
laboratory by s~,LI,~ ,,-g thr~ dimethyl esters of adipic acid,
succinic acid, ând glutaric acid in the plupGI liul-s of 10 wt%/22
wt%/68 wt%, ~ ?~ /uly. Soiled coupons were immersed in a
mixturâ of the dibasic esters with HFC-365 (CF3CH2CF2CH3) ât 56 C
for 30 seconds, followed by â 30 second ;,~"~ ,iol~ in HFC-365 at
ambient temp~râture and â 30 second vapor rinse with HFC-365.
The following results were noted:
Expt. Oil on Substrate Cleaning Method 1~ uy~ lla
(ug) Carbon
on the Surfac~
~efore After
Cleaning Cleaning
25 (a) ,: ~ ' this invention 819 11
~b) petroleum no HFC rinse 819 495
(c~ petroleum no ester rinse 819 70
(d) synthetic this invenbon 508 10
(e) synthetic no HFC rinse 508 724
3s (f) synthetic no ester rinse 508 499
-43 -
WO 94/28196 PCT/US94106004
2~3~1
.
In the eA~Jtl(i~ll~lll~ with the petroleum and synthetic oils, using anorganic cleaning step followed by a fluo,ul~l~e,,,ical vapor rinse step
resulted in co"",l~t~ly cleaning the coupon surface (>99.9% .
removal of carbon~. However, in aA~,~,i",~"L~ (b) and (e), siy"iri~
5 amount of carbon remained on the surface when the coupon was
cleaned by a 30 second i"""~r~;on in dibasic ester only followed by
a 30 second drying in air without the HFC vapor rinse. In
ex~.e"i",~"l:. (c) and ~f), ~;~",;ri~ ~,"L amount of carbon residue
remained on the surface when the coupon was cleaned by a 30
second ;"""~,~;ol- in HFC-365 followed by a 30 s~cond drying in air
without using the ester eleanin~ step. This example c:~."o" ,l,"L~s
that a flu~lu,,l~lll;c~l vapor rinse step is required to C~ v clean
a soiled surfaee whieh has been immersed in either a dibasie ester or
a mixture of a dibasie ester with fluu~u~ l, and neither the
15 ester alone nor the fluu~ocln~ .al solvent alone is suffiei~nt to
c~" ' t~.ly elean the surfaee.
FY~rnDle Three
Soiled eoupons were immersed in a 50/50 volume % mixture
20 of c~ A."-~n~. a eyelie keton~, and HFC-365, a hydrofluo-
roearbon, for 30 seeonds at 57-59C followed by a 30 second
;,.""~.,.;~n in HFC-365 at ambient temperature and a 30 second
vapor rinse with HFC-365. The lFollowing results were noted:
-44-
wo 94/28196 PCT/US94/06004
~1~3351
Expt. Oil on Substrate Cleaning Method M: uylallls
(ug~Carbon
on the Surface
Before After
Cleaning Cleaning
(a) petroleum this invention 819 8.7
(b) petroleum no HFC rinse 819 1064
(c) petroleum no ketone cleaning 819 70
(d) synthetic this invention 508 7.7
(e) synthetic no HFC rinse 508 1475
(f) synthetic no ketone cleaning 508 499
lg) mineral oil this invention 950 7.5
(h~ synthetic this invention 1033 14.9
In the ~A,u_.i~l_.lla (a) through (f) using an organic cleaning step
25 followed by a fluolu.,ll_.llicdl vapor rinse step resulted in Col", ' 'y
cleaning the coupon surface (>99.9% removal of carbon).
However, in ~ a (b) and (e), ~.iu"iri~.~",l amount of carbon
remained on the surface when the coUpon was cleaned by a 30
second i~ .aiull in c~ ulle only followed by a 30 second
30 drying in air without the HFC vapor rinse. In ~A~ a (c) and (f),
~iul- Il amount of carbon residue remained on the surface when
the coupon was cleaned by a 30 second ill~n~a~ in HFC-365
followed by a 30 second drying in air without using the ketone
cleaning step. This example d~..llOIlal~ that a ~luo,u~ .";~ a
35 vapor rinse step is required to c_..., ' ~y clean a soiled surface
which has been immersed in eith-r ketone (cyclic or acyclic) with
WO 94/28196 ~ 1 6 3 3 5 ~ PCT/US94/06004
fluo,u~ ,,,ical, and neither the ketone alone nor the fluorocl~e",;~ al
solvent alone is sufficient to c~",~J!ut~'y clean the surface.
Exam~l~ Four
Soiled coupons were immersed in a 50/50 volume %
mixture of liquid cV~lo~ .a~ol, a cyclic alkanol and HFC-365, a
hydroflu~ocO,Lon, for 30 s~conds at 57-59C followed by a 30
second il,...,~ in HFC-365 at ambient temperature and a 30
second vapor rinse with HFC-365. The following results were
10 noted:
Expt. Oil on Substrate Cleaning Method ~ ' u~. .." ~:, (ug~
Carbon on the
Surface
Before Aner
Cleaning Cleaning
(~) petroleum this invention 819 4
(b) petroleum no HFC rinse 819 2397
(c) petroleum no alkanol cleaning 819 70
(d) synthebc this invention 508 139.7
(a) synthetic no HFC rinse 508 1148
(fl synthebc no alkanol cleaning 508 499
(9~ mineral oil this inv~ntion 950 12.7
(h) synthetic this invention 1033 10.2
-46-
Wo 94/2X196 ~ 1 ~ 3 3 a 1 PCT/US94/06004
In the e,.~,eri,,,e,,lb with petroleum oil, using an organic cleaning step
followed by a fluo,ocl,c",;cal vapor rinse step resulted in colllple~
cleaning the coupon surface ~>99.9% removal of carbon). Since
cyclohexanol is a fairly poor solvent in cleaning synthetic oil, as
shown in ~ lilllenL~ (b~ and le), most of the oil and the organic
solvent film was able to be removed with the cieaning process of
this invention as shown in e~ lilllell~ (d). AddiLiun "y, in
.i",_.,l:. (b) and (e~, a s;~,.iri. a"l amount of carbon remained on
the surface when tha coupon was cleaned by a 30 second
illllllel~idl~ in c~ h_,~ ol only followed by a 30 second drying in air
without the HFC vapor rinse. In ~ J_.illl6llla (C) and (f), Si~,iri~a~l
amount of carbon residue remained on the surface when the coupon
was cleaned by a 30 second illllllt~laiun in HFC-365 followed by a
30 second drying in air without using the alkanol followed by a 30
second drying in air without using the alkanol cleaning step. This
example d~..llvllal~t~.~ that a fluv.v,.l,_...;~ al vapor rinse step is
required to ~ ' I 'y clean a soiled surface which has been
immersed in an alkanol (cyclic or acyclic), and neither the alkanol
alone nor the fluo,v..l.~...ic~l solvent alone is sufficient to cv". t. ly
20 clean the surface.
Example Fiv~
Soiled coupons were immersed in a 50/50 volume % mixture
of liquid 1,-5- " ..ull.~llcy~'~o .~, a cyclic olefin, and HFC-365,
a hydrofluv,oc~.vdn, for 30 seconds at 57-59C followed by a 30
second i.. _.~idn in HFC-365 at ambient temperature and a 30
second vapor rinse with HFC-365. The following results ware
noted:
-47 -
WO 94/28196 PCT/US94106004
~63351
Expt. Oil on Substrate Cleanlng Method ,~ uylalllS ~ug~
Carbon on the
Surface
Before After
Cleaning Cleaning
(a) petroleum this invention 819 10.1
(b) petroleum no HFC rinse 819 2953
(c) petroleum no olefin cleaning 819 70
(d) synthetic this invention 508 18.8
(e) synthetic no HFC rinse 508 2831
(f) synthetic no olefin cleaning 508 499
(9) mineral oil this invention 950 10
Ih) synthetic this invention 1033 15.1
In the ~Au_.i~ llla with petroleum oil and synthetic oil, using an
25 organic cleaning step followed by a fluGIu.,l~ l;.,cll vapor rins~ step
resulted in ,u~ cleâning th~ coupon surfacu (>99.8%
removal of carbon). Howev~r, in ~A~ J~lla (b) and (e), aiy"iri.,~"
amount of carbon remained on th3 surface when the coupon was
cl~aned by a 30 second i~ a;ùl~ in 1,5 ' "~.thtl~ o " ~e
30 onlv followad by a 30 second drying in air without the HFC vapor
rinso. In t, i It~. (C) and ~f), siyl~ ~ 1l amount of carbon
residus remained on the surface when the coupon was cleaned by a
30 second il~ a~aiull in HFC-365 followed by a 30 second drying in
air without using the olefin solvent cleanin~ step. This example
35 du.~lullaLI.~t~ that a fiuo,u~.l,_.ll;~.~l vapor rinse step is required to
c~., ' I '~ clean a soiled surface which has been immersed in an
-4~-
WO 94/28196 ~ 1 ~ 3 3 5 ~ PCT/US94/06004
olefin (cyclic or acyclic), and neither the olefin alone nor the
fluo,uclle",;~l solvent alone is sufficient to c~",, '~t~,ly clean the
. surface.
5 E Y:~'IlDIe Six
Soiled coupons were immersed in a 50/50 volume ~0 mixture
of liquid benzotrifluoride, a fluorinated aromatic chemical, and HFC-
365, a hydrofl~o~u~a, u~ll, for 30 seconds at 57-59C followed by a
30 second illll~l~la;ol) in HFC-365 at ambient temperature and a 30
10 second vapor rinss with HFC-365. The following results were
noted:
Expt. Oil on Substrate Cleaning Method ~ uyl al, la lug)
- Cârbon on the
Surface
Before After
Cleaning Cleaning
(a) petroleum this invention 819 13.3
(b) petroleum no HFC rinse 819 138
25 ~C) petroleum no fl. org. cleaning 819 70
(d) synthetie this invantion 508 16.1
(e) âynthetie no HFC rinâe 508 1022
(fl synthetic no fl. or~. eleaniny 508 499
(~) minerâl oil this invantion 950 13.7
35 (h) synthetie this invention 1033 127.9
-49 -
wo 94/28196 PCT/US94106004
~1633~1
In the e~u~:,i",~"l~ with petroleum oil and synthetic oil, using an
organic cleaning step followed by a fluGruch~,,,ical vapor rinse step
resulted in c~""~lut~.~/ cleaning the coupon surface (>99.8%
removal of carbon). However, in elAUelilll~ > (b) and (e), Siu~iri~
amount of carbon remained on the surface when the coupon was
cleaned by a 30 second i"""~(:,io~ in benzotrifluoride only followed
by a 30 second drying in air without the HFC vapor rinse. In experi-
ments (c) and (f), Siy,,;ri,,c,,,l amount of carbon residue remained on
the surface when the coupon was cleaned by a 30 second
i"""~,~;on in HFC-365 followed by a 30 second drying in air without
using the flu~oa~ lal;~. cleaning step. This example d6~1~0~
thât a fluon,~.l,_.,.;~ dl vapor rinse step is required to cu,,,~ uly clean
a soiled surface which has been immersed in a fluorinated aromatic
solvent, and neither the fluu~u~u~ t;_ cleaning solvent alone nor
the flu~lu~l,_., solvent alone is sufficient to cu,,,~lutuly clean the
surface.
EY~rnDle Seven
Soiled coupons were immersed in a 50 volum~ % mixture of
pUly-~lltlu~l~ glycol (MW 200~(a polyether diol~ and a methyl ester,
and 50 volume % of HFC-365, a hydroflu~,uc..~L~nr for 30 seconds
at 45-50C followed by a 30 second i..""_.:.;ùn in HFC-365 at
ambient temperature dnd a 30 second vapor rinse with HFC-365.
The following results were noter~:
-50-
Wo 94/28196 ~16 3 3; 1 PCT/uss4/06004
Expt. Oil on Substrate Clesning Method Micrograms (ug)
Carbon on the
Surface
Before After
- Cleaning Cleaning
(a) petroleum this invention 819 14
10 (b) petroleum no HFC rinse 819 1917
(c) petroleum no PEG/ester cleaning 819 70
(d) synthetic this invention 508 11
(e) synthetic no HFC rinse 508 1847
(f) synthetic no PEGlester cleaning 508 499
(~) mineral oil this invention 950 12
(h~ synthetic this invsntion 1033 13
in the ~A,V~ lla with petroleum oil and synthetic oil, using an
25 organic cleanin~q step followed by a fl~u~ alll;cal vapor rinse step
r~sulted in c , ' 'y cleaning the coupon surface (>99.8%
removal of carbon). However, in ~ .i",~ s (b) and (e), si~"ir,ca"
amount of carbon remained on the surface when the coupon was
cleaned by a 30 second i""" .si~n in ~ol~utl,/l~ glycol/methyl
30 ~ster solvent mixture only followed by a 30 second drying in air
without the HFC vapor rinse. In aAp~,.ill._.lla Ic) and (f), a;~liril,alll
amount of carbon residue remained on the surface when the coupon
was cleaned by a 30 second i,,,,,.~..siu,, in HFC-365 followed by a
30 second dryin~ in air without using the glycol/ester solvent
35 cleaning step. This example d~,.llulla~ t~ that a fluofucl, .,
vapor rinse step is rQquired to cu.l, - ~y clean a soiled surface
wo 94/28196 PCTIUS94/06004
21~33~1 ~
which has been immersed in a mixture of glycol with an ester, and
neither the mixed organic solvent alone nor the fluo,u~,h~,,,i.,dl
solvent alone is sufficient to c~ Jt~ ly clean the surface.
ExamDle Eiaht
Soiled coupons were immersed in either a methyl ester, or a
mixture of polyethylene glycol (MW 200)(a polyethsr diol) and a
methyl ester, for 30 seconds at 57-59C followed by a 30 second
i"""~,:,iu,l in either HCFC-123, a ~/d~u~ lu~urluu,u~a~l,on~ or HFC-
52-13, a highly fluorinated alkane, at ambient temperature and a 30
second vapor rinse with either flu~lvul~"~;ual solvent. The following
results were noted:
(a) The synthetic oil and the grease Valvoline were both
ramoved from metal coupons to better than 99.9% using the PEG-
200/methyl ester cleaning solvent mixture with HCFC-123 as the
rinse solvent in the process of this invention.
(b) Same as (a) with 123 replaced by HFC-52-13 which is
(CF3)2CHCF2CF2CF,.
2 o FYA~nDle Nine
Soiled coupons were immersed in a 50/50 volume % mixture
of BIOACT EC-7, a cu~,~". .~ l blend of terpenes and nonionic
surfactants, and HFC-365, a hydrofluu~u.,a~L.u~, for 30 seconds at
57-59C followed by a 30 second ;,....~ ;ùn in HFC-365 at ambient
25 temperature and a 30 second vapor rinse with HFC-365. The
tollowinll ros~lts wors nots
WO 94/28196 ~16 3 3 5 ~ PCT/US94106004
Expt. Oil on Substrate Cleaning Method M;l Oylalll~ (ug)
- Carbon on the
Surface
Before After
Cleaning Cleaning
la) petroleum this invention 819 15.3
10 (b) petroleum no HFC rinse 819 2221
(c) petroleum no terpene cleaning 819 36
(d) synthetic this invention 508 13.6
(e) synthetic no HFC rinse 508 2272
(f) synthetic no terpene cleaning 508 27.9
20 (g) mineral oil this invention 950 12
(h) mineral oil no terpene cieaning 950 94
(i) synthetic this invenbon 1033 13
a) synthetic no terpene cleaning 1033 340
In the ~A~ n~ a with petroleum oil and synthetic oil, using an
organic cleaning step followed by a flu~,u~ ,dl vapor rinse step
30 rr~sulted in virtually complete cleaning of the coupon surface
(>99.696 removal of carbon). However, in ~A~ (b) and (e),
~iu~iri~n~l amount of carbon remained on the surface when the
coupon was cleaned by a 30 second ;",.,.~.:,;..,~ in the terpene
solvent mixtur~ only followed by a 30 second drying in air without
35 the HFC vapor rinse. In ~ .;".- .,t~ (c) and (f), s;~" ' ,l amount
of carbon residue remained on the surface when the coupon was
cle~ned by a 30 second ;.~ ,;on in HFC-365 followed by a 30
-53 -
WO 94/28196 21 S 3 3 ~1 PCT/US94106004
second drying in air without using the terpene solvent cleaning step.
This example cl~i"on~l,alt,s that a fluOIuc~l~nll;~al vapor rinse step is
required to culll~,luL~ly clean a soiled surface which has been
immersed in a terpene solvent, and neither the terpene solvent alone
nor the fluO(OCI-~illl;.,al solvent alone is sufficient to c~"",ul~t~ly clean -the surface.
FYs~ Dle Ten
Soiled coupons were immersed in 50/50 volume % mixture of
liquid cyclo~,~Aanona, a cyclic ketone, and HFC-365, a hydrofluo-
rocarbon, for 30 seconds at 56-59C followed by a 30 second
i"",. .aion in a nu"tla""" ' ' constant-boiling blend of 5% HCFC-
141 b, a l"~l~ù~ utlu~u~,albol~, and 90% HFC-365, a hydrofluo-
rocarbon, at ambient temperature and a 30 second vapor rinse with
the cul,da,~i"g ~ul~ ui~ vapors of HCFC-141b/HFC-365. The
following results were noted:
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WO 94/28196 ~ 1 ~; 3 3 ~1; PCT/US94/06004
E%pt. Oil on Substrate Cleaning Method Micrograms (ug)
Carbon on the
Surface
Before After
Cleanins Cleaning
(a) petroleum this invention 819 18
0 (b) petroleum no HFC/HCFC 819 2221
blend rinse
(c) petroleum no ketone cleaning 819 70
(d) synthetic this invention 508 29
(e) svnthetic no HFC/HCFC 508 2272
blend rinse
(f) synthetic no ketone cleaning 508 499
(g) mineral oil this invention 950 15
(h) synthetic this invention 1033 25
In the e.,~J.,.i",~,"t~ with petroleum oil and synthetic oil, using an
organic cleaning step followed by a fluu~u~ ,al blend of HCFC
and HFC vapor rinse step resulted in virtually complete cleaning of
t~e coupon surface (>99.8% removal of carbon). However, in
30 u~yv~i~n-nLa (b) and (e), ;.i~,-ifica"l amount of carbon remained on
th~ surface when the coupon was cleaned by a 30 second
;....r..aion in the ketone cleanin3 solvent only followed by a 30
second dryin~ in air without the HCFCIHFC vapor rinse. In
..,~.~,.i,.l~.,b (c), (f), (h) and a,, more carbon residue remained on the
35 surface when the coupon was cleaned by a 30 second il~ l.,.aiOI~ in
HCFC-141b/HFC-365 ~ u~,~ followed by a 30 second drying in
air than in the dual solvent process of this invention using the
WO g4/28196 PCT/US94/06004
~163351
terpene solvant cleaning step. This example de~lllOI l ~la~s that even
when a strong fluo(~ul,t:",i~,al rinse solvent such as a b!end
~o"~:., ,g HFCF-141b is used, the combined organic Iketone)
cleaning step followed by a fluolu~ lllical rinse step produces
s greater cleaning than if a ketone solvent alone or a fluu~clcll~llli~dl
solvent alone is used to clean the substrate.
FY~ nDle Eleven
Soiled coupons were immersed in a 50/50 volume % mixture
of liquid ~,tclol.a,~al~o~1~. â cyclic ketone, and HFC-365/FC-72 195:5
by weightl for 30 seconds at 56-59C followed by a 30 second
,iùn in a non ~ blend of 5% FC-72, a
perfluu,oca,Lvn, and 95% HFC-365, a hydrofluu,u~.a,L~n, at
ambient temperature and a 30 second vapor rinse with the
co~,~u~ a~ LIu~, vapors of FC-72/HFC-365. the following
results were noted:
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WO 94/28196 ~1~ 3 ~ 5 1 PCTIU594106004
Expt. Oil on Substrate Cleaning Method ~1~ uy,c..":. (ug)
Carbon on the
Surface
- 5 Before After
Cleaning Cleaning
(a) petroleum this invention 819 22
10 (b) petroleum no k~tone cleaning 819 44.3
(c) synthetic this invention 508 20.1
(d) synthetic no ketone cl~aning 508 453
(e) mineral oil this invention 950 21.3
(f) mineral oil no ketone cleaning 950 550
20 (~q) synthetic this invention 1033 20.4
(h) synthetic no ketone cleaning 1033 426
In the above ~.A~C.i..~ , using an orga liC cleanin~ step followed
25 by a flU~u~ .ll;Cdl vapor rinse step resulted in complete cleaning of
the coupon surfac~ ~99.9% removal of carbon). More carbon
r~sidu~ remained on the surface when the coupon was cleaned by a
30 second il",.,~. ,;ùn in the mixture of FC-72/HFC-365 followed by
a 30 second dryin~ in air without usin~ the ~ lùh~a~lull~ solvent
30 cleanin~ step. This example d~ll.ù~ t~,~ that a fluc,lu.,ll_.,,;.,al
vapor rinse step is required to ~ 'y clean a soiled surface
which has been immersed in a ketone solvent, and neither the
ketone solvent alone nor the fluc,lu,;ll .I;~.dl solvent alone is suffi-
cient to ~ r clean the surface. In addition, it is well known
35 that perfluulu~,albùns such as FC-72 are very poor solvents for oils,
but when blended with ~l~d~cl '( ùc_.Lùns or even
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Wo 94/28196 PCT/US94/06004
~1633~1
I~J~u~ orluorucd,uons in the vapor or i"""~, aiùl~ rinse step of this
process eombined with an organic eleaning step, the dual solvent
process produces c~,,,,~JIvtvly clean coupons which could not be ..
co,,,~,lutuly cleaned by the individual solvent II,_."_uh,es.
..
FY ~nDle Twelve
Soiled coupons were immersed in liquid c~cl~htl~allùl, a cyelic
aleohol, which was not admixed with the HFC prior to cleaning (as
in the previous ~ "Jle~). The eoupons were immersed for 30
seeonds at 56-59C followed by a 30 seeond ill~ _.aiùl~ in HFC-
365, a hydroflv~oca,L~n, at ambient temperature and a 30 seeond
vapor rinse with the vul~dvrlai,l~ a~e~b~ vapors of HFC-365. The
followin~q results were noted:
Expt~ Oil on Substrate Cleaning Method r1i vg,a",a (ug)
Carbon
on the Surfaee
Before After
Cleaning Cleaning
(a) petroleum this invention 819 18.5
(b) synthebe this invention 508 166
(e) mineral oil this invention 950 20.9
(d) synthetie this invention 033 22.4
In this e,~ .i",_.,l, the eleaning ability of the or~qanie eleaner
~ ar~lt~ d from the HFC was ~ vt~.~. The results are within
35 I;A,l,~.~.illlV. Ilal error to those of r-xample 4, where the admixed
-sa-
.
WO 94/28196 ~16 3 3 51 PCT/IJS94106004
organic/solvent system was evaluated. I"L~ L;"yl~, in this example
the HFC/organic mixture in the cleaning sump cleaned better than if
the cleaning sump contained only organic solvent (~.~CIOlleAclllol).
FY ~mDIe Thirteen
Soiled coupons were immersed in liquid C~ ùlll~Aano~el a
cyclic ketone, which was not admixed with the HFC prior to cleaning
(as in the previous eA.",. q~. The coupons were immersed for 30
seconds at 56-59C followed bV a 30 second in""_(~;o,) in HFC-
365, a hydrofl~o,ùc.-,Lu,,, at ambient temperature and a 30 second
vapor rinse with the cond~ ;"~ aL~ up;~ vapors of HFC-365. The
followirlg results were noted:
Expt. Oii on Substrate Cleanin~ Method ~' u~lal"s (u~)
Carbon
on the Surface
2 0 Before After
Cleaning Cleaning
(a) petroleum this invention 819 11.3
25(b) synthetic this invention 508 12.2
(c) mineral oil this invention 950 11.7
(d) synthetic this invention 1033 10.3
In this ~A,U_.i~ , the cleaning ability of the organic clr~aner
5~ .t~ d from the HFC was d, ."~f,~ ' The results are within
C~A~JCli~ l error to those of Example 12, where the admixed
35 organic/solvent system was u;. ' '
-59 -
WO 94/28196 PCT/US94106004
21~33~
It will be readiiy seen by one of ordinary skill in the art that
the present invention fulfills all of the objects set forth above. After
reading the foregoing -ueciric~lion~ one of ordinary skili will be able
to effect various changes, substitutions of equivalents and various
other aspects of the invention as broadly disclosed herein. It is
therefore intended that the ,ulul~liol~ granted hereon be limited only
by the definition contained in the appanded claims and equivalents
thereof.
-60-
