Note: Descriptions are shown in the official language in which they were submitted.
~313~
IR-4466 THICKENED AQUEOUS NO- OR LOW-
PHOSPHATE BUILT CLEANING COMPOSITION
The pre~ent inventlon relate~ to aqueou~ cleaning
compo~ition~ for cleaning dishes and the llke, especially in an
automatic dishwasher. More ~pecifically, the lnventLon eelate~
to such compo~itions which do not include any phosphate builders
5 but which giYe comparable or superior cleanlng performance to
similar phosphoru6 con~aining liquid automatic dish~asher
detergent compo~itions.
The present inventisn speciflcally relates to thickened
liquid automatic dishwashing detergent co~po~itions having
10 vlscoelastic properties, improved chemical and physical
6tablllty, and with increased cleanlng performance despite the
ab~ence of pho~phate bullder ~alts and which are readlly
di~per~ible in the washing medium to provide effective cleaning
of dishware, glassware, china and the like.
Commercially available household-machine dl6hwasher
detergents provided in powder form have several disadvantages,
e.g. non-unlform composition; co~tly operations necessary ln
thelr manufacture tendency to cake in storage at high
humidities, resulting in the formation of lumps which are
difficult to disperse5 dust~ne~s, a source of particular
irritation to u~er~ who ~ufer allergie~ and tendency to cake in
the di~hwasher mach~ne dispenser. Liquid form~ o~ such
compositions, however~ generally oannot be used in automatlc
di~hwa~her~ due to high foam levels, unacceptably low visco~ties
and exceedingly hlgh alkalinity.
Recent research and development activity has ocused on
the gel or ~thixotropic" ~orm of such compo~itions, e.g. scouring
clean6ers and automatic-dishwasher product~ characteeized as
~- ~31~2~3 ~-
thixotropic ll~uid~ or pastes. Dishwasher products 80 provided
are p~i~arily objectlonable in that they are ~nsufflciently
viscou~ to remain ~anchored~ in the di~penser cup of the
dishwasher, and moreover yield spotty residue~ on d~shware,
gl~32ware, china and the like.
The provision of automatic-d~shwasher compositions in
gel form having 6atis~actory dispenslng etability and cleanlng
properties has thus far proven problematical, partlcularly as
~egards compositions for use ~n home dlshwasher machine~. For
effective use, it is generally recommended that the automatic
dishwashing detergent, hereinafter also designated ADD, contain
(1) sodium trlpolyphosphate (NaTPP) to soften or tie up hard-
water minerals and to emulsify and/or peptize soil5 ~2) sodium
~ilicate to supply the alkalinity necessary ~or effective
1~ detergency and to provide protection for Eine china glaze and
patternt (3) sodium carbonate, generally considered to be
optional, to enhance alkalinity~ (4) a chlorine-releasing agent
to aid in the eliminatlon of soil specks which lead to water
spottlng~ and (5) defoamer/surfactant to reduce foam, thereby
enhancing machlne e~ficiency and supplying requlslte detergency.
See, for example~ SDA Detergents in Depth, ~Formulations Aspects
of Machine Dishwashingr~ Thomas Oberle (1974). Cle3nsers
approximately to the aforedescrlbed compositions are mostly
l~quids or powders. Combining ~uch ingredlents in the thickened
form effective for home-machlne u~e has provided dlfficult.
Generally, such compo~itions oMit hypochlori~e bleach, since it
tends to react with other chemically active ingredients,
particularly surfactant, theceby degrading the ~u~pending or
thickening agent and impairing lt~ effectivenes~.
U.S. Patent 4,115,308 discloses thi~otropic automatic
~ 1 3 ~
diuhwa~her pa~tes containing a suspending agent, e.g. CMC,
synthetic clays or ~he likeJ lnorganlc salts including silicates,
pho~phates and polyphosphates~ a small amount of surfactant and
a ~uds depressor. Bleach i5 not disclosed. On the other hand,
U.S. Patent 3,684,722 dlscloses alkali metal hypochlorlte
bleaching and cleaning composition ~hickened with mlxtures of Cg-
Clg alkali metal soaps and hydrotrope~, ~uch as amine oxide and
betalne~. Patentees describe te~ts that show that var~ous
classes of organic polymer thickeners were either unstable or
otherwise failed ~o provide adequate thickening or re~ulted in
loss o~ available chlorine. The polyacrylates were found to
provide thickening for ~everal weeks at room temperature but ~hen
decomposed.
U.S. Patent 3,985,668 describe~ abra~ive scouring
cleaner~ of gel-llke consistency containing (1) ~uspending agent,
preferably the Smectite and attapulgite types of clays (2)
abr~sive, e.g. silica sand or perlite~ and (3) flller compri~ing
light density powdered polymer~, expanded perlite and the llke,
which has a buoyancy and thus stabllizing effect on the
composit~on in addition to servlng a~ a bulking agent, thereby
replacing water otherwise available for unde~ired supernatant
layer formation due to leaking and phase destabllization~ The
fvregoing are the es~entlal ingredlents. Optional ingredient~
include hypochlorite bleach, bleach atable surfactant and buffer,
e.g. ~ilicates, carbonates, and monophosphates. Builders, such
as NaTPP, can be included a~ further optional ingredlents to
~upply or supplement building function not provided by the
buffer, the amount of auch builder not exaee~3ing 5~ o~ ~he to~al
composition, accordlng to the patent. Malntenance of the aesired
~greater than) p~ 10 level~ i~ achieved by the buffer/builder
~ 31~ 3 ~_
components. High p~ is sald to min1mize decompos1t1on of
chlorine bl~ach and undesired interaction between surfactant and
ble~ch. When pre3ent~ NaTPP i8 limi~ed to 5~, a~ ~tated. Foam
klller i~ not disclosed.
In U.~. Patent Applicatlons GB 2,116,199A and GB / /
2,140,450~, both of which are a~signed to Colgate-Palmolive,
liquid ADD (LADD) compositlons are disclosed which have p~oper-
i tie~ desir~bly characterlzing thlxotroplc, gel-type ~tructure and
whi~h have varlous ingredlentq necessary for eff2ctive detergency
with an automatic dishwasher. The normally gel-like aqueous
automatlc dishwa~her detergent composition having thlxotropic
properties includes the following ingredients, on a we~ght basls:
(a) 5 to 35% alkali metal tripolyphosphate5
(b) 2.5 to 20% ~odlum sllicate
lS (c) 0 to 9% alkali metal carbonate~
(d) 0.1 to 5~ chlorine bleach stable, water disper~ible
organlc detergent active material~
(e) 0 to 5~ chlorine bleach stable foam depre~sant~
(f) ~hlorine bleach compound in an amount to provlde
about 0.2 to 4~ of available chlorine~
(g) thixotropic thickener ln an amount ~ufflci~nt to
provide the compo~it~on which thixotropy lndex of about 2.5 to
10~
~h) sodium hydroxide, a~ nece~ary, to ad~u~t pHs and
(i) water.
LAD~ compositions ~o formulated are low-foaming5 are
readily ~oluble ~ the washing medium and mo~t effective at
alkaline pH value~. The compoeition~ ~re norm~lly o~ gal
consistency, i.e. a highly vlscou~, opaque ~elly-l~ke material
having Bingham pla~tic character and thuq relatively high yleld
13~2~ ~
62301-1502
values. ~ccordlngly, a de~lnlte ~hear force 18 nece~ary to
lnltlate or lncrease low, such as would obtaln wlthln the
agl~ated dlspenser cup of an energlzed automatlc dl~hwasher.
Under such conditions, the compositlon is qulckly Elu1dlzed and
eas1ly di~persed. When the shear foece 1~ dl~contlnued, the
fluld composition qulckly reverts to a hlgll v1scoslty, Dlngllam
plastlc atate closely approxlmatlng it~ prior conslstency.
U.S. Patent 4,511,4~7, dated ~prll 16, l985, de~crlbe0
a low-foaming detergent pa~te for dl~hwa~hersO The patented
thixotropic cleanlng agent has a vlscoglty of at least 30 Pa.s at
20C as determined wlth a rotational vlscometer at a ~plndle
speed of 5 revolutlons per mlnute. The compog1tlon i8 based on a
mlxture oE finely dlvlded hydrated sodium tcipolypho6phate and
hydrated sodlum metasillcate, an actlve chlorlne compound and a
lS thlckenlng agent whlch i8 a follated slllcate of the hectorite
type. Small amount of nonlonlc tenslde~ and alkall metal
carbonates and/or hydroxldes may be used.
Recently, appllcant has developed var10us modif1catlons
and lmprovements ln llquld automatlc dl~hwa~her detergent
composltlons oÇ G~ 2,116,199A and GB 2,140,450~. For example.
Canadian Application No. 526,708 discloses aqueous gel-like
thlxot~opic clay-re~ and polymer th1ckener-free liquld cleanlng
composltlons which utlllze a mono- or polycarboxyllc acld havlng
from 8 to 22 ca~bon atoms to impart phy~lcal stabllity and
thlxotroplc propertles.
In commonly a6slgned Canadian appllcatlon No.
546,121 the physlcal stablllty of clay based thlxotroplc 11quld
bullt automatic d1~hwash1ng detergent composltlons 1s lmproved by
additlon thereto of small amount~, ~or example, from about 0.02
3J ¦¦ to 1 by welght, oE a polyva1ent metel ~alt oE a long chaln Eatty ¦
,:~
1 3 ~ ~ ~ L ~
62301-1502
acid, such as aluminum stearate.
The majority of these disclosed and commercial liquid
automatic dishwasher detergent and similar compositions depend
upon phosphate builder salts, such as sodium tripolyphosphate,
to enhance cleaning performance. While the phosphate builder
salts are highly effective for this purpose, their use has a
major disadvantage: they are harmful to a~uatic life and to
the waterways, in general. In fact, many jurisdictions have or
are considering a general ban on phosphate containing cleaning-
detergent products.
Although there have been many attempts to providealternative builders and many such non-phosphate inorganic and
organic detergent builder salts are known very few are capable
in practice of providing comparable cleaning benefits to the
phosphate bullders. Furthermore, selection of suitable
builders is even mora difficult in the environment of the
present bleach containing aqueous compositions since the
alternatlve builder must be chlorine bleach compatible.
In addition to its function as a detergency builder,
the inorganic alkali metal phosphate salt builder provides an
important function in contributing to the rheological
properties of the thickened thixotropic gel-like liquid aqueous
detergent compositions such as described above in GB 2,116,199A
and GB 2,140,450A. Accordingly, replacing the phospha~e
builder with a non-phosphate buildex has not proven to be a
simple task since so many different factors must be taken into
consideration in fulfilling all of the multifunctional ~asks of
the phosphate builder.
Accordingly, the invention seeks to provide aqueous
bleach containing cleaning compositions which avoid the use of
phosphate builders and containing no or only environmentally
i~
~ 3 1 ~
62301-150
tolerable levels of phosphorus from other sources.
The invention also seeks to provide no or low
phosphate thickened liquid ADD compositions with improved
physical stability and rheological properties.
The invention further seeks to provide thickened
liquid ADD compositions having no or low levels of phosphorus
without adversely affecting or while improving cleaning
performance, particularly low spot and film formation.
The invention will become more readily understood
from the following detailed description of the invention and
preferred embodiments thereof which are accomplished by an
aqueous liquid low- or no-phosphorus cleaning composition
comprising water, a detersively effective amount of a chlorine
bleach-stable water dispersible organic detergent, chlorine
bleach, more than 25% by weight of an alkali metal silicate and
a building effective amount of a detergent builder, wherein the
detergent huilder comprises a mlxture of aluminosilicate
zeolite and carboxyl group-containing bleach-stable water-
soluble polymer, or a salt thereof. More particularly,
according to a preferred and specific embodiment of the
invention, there is provided a thickened viscoelastic liquid
automatic dishwasher detergent composition which is free of
phosphate builder salts and contains no or only low levels of
phosphorus and which is effective to inhibit settling of the
water-insoluble suspended particles, such as the
aluminosilicate zeolite builder, bleach particles, etc. The
composition may include clay or other thickeners as well as
other stabilizing agents and other conventional ADD additives.
In accordance with this particular aspect, the
present invention provides a normally gel-like aqueous
automatic dish-
13182~
wa~her detergent composition havlng vl~coelastic propertie~
which include, on ~ ~eight ba~
(al 5 to 35~ alumino~ilicate zeollte~
(b~ 25 to 40% ~odium ~llicate~
(c) 0 to 9~ alkali metal carbonatet
(d) 0.1 to 5~ chlorine bleach ~table, water dispersible
_ organic detergent active materlalt
(c) 0 to 5~ chlorine bleach stable foam depressant5
(f) chlorine bleach compound ~n an amount to provide
~bout 0.2 to 4% of available chlorine~
(g) 0 to 0.5~ of a long chaln fatty acid or ~alt
thereof7
(h) 0 to 5% of a clay thickener~
~i) 0 to 8~ sodium hydroxide1 and
~) balance water.
Also related to thi~ speclfic a~pect, the lnvention
provide~ a method for cleaning di~hware in an automatic
dishwashing machine with an aqueou~ wash bath conta~ning an
effectlve amount of the liquid automatic dl~hwa~her detergent
(LADD) compo~ition as described above. Accordlng to this aspect
of the invention, the LADD compo~ition can be readily poured into
the dispensing cu~ of the auto~atlc dishwashlng machine and will
be ~ufficiently viscous, to remain securely within th~ dispensing
cup untll ~hear force~ are applied thereto, such as by the water
~pray from the dlshwashing machine, whereupon the yield value of
the compo~ltion will be exceeded and the compQsitlon will ~low.
The invention will now be de~cr~bed in greater detail
by way of ~pecific embodiments thereof~
In view of envlronm~ntal concerns stemmlng from the
problem of elutr~ficatlon of lakes, rl~er~ and other waterway~
~3~g~
attributed to the depositing of pho~phorus ~rom detergents andother product~ into the waterway~, there has been a good deal of
emphasis on removlng the phosphate~ from detergent products.
However, attempts to replace the phosphate bu~lder from
thlxotropic liquid automatic d~hwasher composltions of the type
u~ed by the as~ignee of the sub~ect appllcation and which
typ~cally include 0 to 3~ clay thickener - gen~rally of the
~mectite water - swelling typet 10 to 25~ of ~lkali metal
~ silicat~5 0 to 0.5~ fatty acid ~tab~llzerl small amount~ of
¦ bleach, bleach stable detergent, bleach stable anti-foam agent,
sodium carbonate, caustic ~oda and the like, and about 20 to 25%
of alkall metal phosphate ~alt as de~ergent builder, have
¦ resulted in 10~8 of thixotropic propertie8 and usually ~or~ening
¦ of cleaning performance. Although the exact mechanl~m of the
¦ dlsruption of the rheological propertle~ c~u~ing 1088 of
¦ thixotropy has not been fully elucldated ~t ~ppears that there 18
¦ at lea~t some interaction between the ~uspended pho~phate bullder
¦ paeticle~ and the other ingredient~ of the formulation,
¦ especially the clay thlckener and fatty acld or fatty acld salt
¦ ~tabilizer and this lnteractlon contribute~ to ~ncreasing the
¦ yleld ~tres~ and pla~tlc vl ~c08ity of the compo~ltion.
¦ The present invention i8 ba~ed upon the ~urpri~lng
¦ discov~ry that similas rheologlcal propertie~ and physi~al
¦ s~abillty, l.e. resl~tance to phase ~eparation, settling, etc.,
¦ a~ ln these prior phosphate-built liquid aqueou~ ADD ~ompositlons
¦ can be achieved by ~ncluding in the compositlon aluminosilicate
¦ zeolite as an lnorganic watee-in~oluble detergent builder in
¦ m~xture with bleach ~table, water-sol~ble, carboxyl group
containing polymer as a multifunctlonal rheological agent and
detergent builder and by increa~ing the level of the alkall metnl
~ 3182~3 62301-1502
¦ sllicate to more than 25~ by welght. ~t the same time, lmprove-
¦ ments in spottlng ~nd Ellmlng performance ll.e. fewer spots and
reduced fllmlng) can be achlevea.
~lthough the compo~ltlon~ of the pre~ent lnventlon do
not exhlbit thlxotroplc properties, they do exhlb~t vlscoela~tlc
propertles and have a yleld polnt (the maxlmum stre6~ in a curve
of shear ~tre~s Yersus ~hear rate) suE~lclently hlgh that they
wlll not flow under the force exerted by thelr own welght, i.e.
gravltational forces. ~herefore, the lnventlon compositlons can
1~ be easlly poured into the dlspen~er cup of an automatic dl~h-
washlng machlne and wlll not flow out un~il a aufflclently hlgh
shear 6tres~, ~uch a~ the force of the water ~et~ lmplnglng on
the cup durlng the detergent dl~perslng cycle, 1~ applled.
Of course, lt 18 under~tood that where phy~lcal
~tablllty for extended perlod~ Oe 6everal week~ or months i~ not
required and where lt is not requlred to provlde a hlghly
thlckened solutlon, the high level~ of elllcate, the clay
thlckener and/or Eatty acld or fatty acld ~alt ~tablllzer can be
omltted Erom the Eormulatlon wlthout adversely effecting the
cleaning perormance provlded by the a1umlno0111cate zeollte
bullder and the water-~oluble caeboxyl group- (~r aalt thereof)
contalnlng bleach atable polymer.
The bullder~ useful hereln are the water-ln~oluble
alumlnoslllcates, both oE the cry~talllne nnd amorph~us type.
2S Varlous cry~talline zeolitee are described in Britl~h Patent
1,5U4,16B, U.S. Patent 4,4~9,136 and Canadlan Patent~ 1,072,B35
and 1,~B7,477. An example of amorphous zeolites useful herein
can be found in selgium Patent 835,351. The zeolites generally
~,. '
~3~2 L3 ~ -
have the formula
~ M2)X-~A123)y-~8102)a-WH20
wherein X 1~ 1, y i~ from 0.8 to 1.2 and preferably 1, z i~ from
l.S to 3.5 or higher and prefeeably 2 ~o 3 and w iB from 0 to g,
S preferably 2.5 to 6 and M i~ an alkali metal, preferably ~odium
or pota~3ium, especially preferably sodium. A typical zeollte 18
type A or ~lmilar structure, with ~ype 4A paeticularly preferred.
The preferred aluminos~licates have calc~um ion exchange
capaclties of about 200 milliequlvalents per gram or greater,
e.g. 400 meq/g.
The alumino~llicate zeollte bullder ~n be present in
the formulations in the same quantities as found useful for the
alkali metal polyphosphate buildee~, generally ln the range of
from about 5 to 35 weight percent, preferably about 20 to 30
weight percent.
The caeboxyl group-containing bleach-stable water-
soluble polymer~ u~eful herein lnclude, for example, the acryll~
acld homopolymera and copolymers and thelr ~alts. These
material~ are generally commerclally available ~nd can be
described a~ follow~.
The polyacrylic acld polymee~ ~nd ~helr ~alts that can
be used compriee water-~oluble low molecular weight polymers
having the formula
t 3 ~ n
wherein the Rl, R2 and R3 can be the same or different and can be
hydrogen, Cl-C4 lower alkyl, or combinat~ons ~hereo~S n i~ a
number of from 5 to 250, preferably 10 to lS0, and more
pre~erably 20 to lOOs and M repreGents hydrogen, or an alkall
metal, ~uch as sodiu~ or pota~lum. The preEerred sub~tituent
~ 13~82~3 ~
for M is sodium.
The preferred Rl, R2 and R3 groups are hydrogen,
methyl, ethy~ and propyl. Pre}erred acrylic monomer i8 one where
Rl and R3 are hydrogen, e.g. acryllc acid, or where Rl and R3 are
hydrogen and R2 i8 methyl, e.g. methacryllc acld monomer.
The degree of polymerization, i.e. the value of n, ifi
generally determ~ned by the llmit comp3tible wlth the solubility
of the polymer or copolymer in water. The terminal or end group~
o~ the polyme~ or copolymer ~re not critical and can be H, OH,
CH3 or a low molecular weight hydro~arbon.
Typically the polyacrylic acld copolymer~ can include
copolymer~ of, ~or example, acrylic acid or methacrylic acid and
a polycarboxylic acid anhydr~de or acid, ~uch a~ succinic
anhydride, ~ucclnic acld, maleic acid, malelc anhydrld~, citric
acid and the llke. Copolymers of acryl~c or methacrylic acid
wlth maleic anhydride are pre~erred.
The acrylic acid or methacrylic acid monomer will
u~ually comprise 40-60 weight p~rcent, e.g. about 50 weight
percent of the copolymer with a polycarbo~ylic ac~d or
anhydride.
The polyacryli~ acld polymer can have a molecular
welght ~weight average~ of 500 or 1~000 to 25,000, preferably
1,500 to 15,000 and especlally prefer~bly 2~000 to 10,000. The
. copolymer~ can have higher molecular welght~, for example, up to
2S ~bout lOO,000.
Specific exa~ples of polyacrylic ac~d polymer3 which
can be u~ed include the AcryBol LMW acrylic ac~d polymer~ from / ,
Rohm and Haa~, ~uch a~ the Acry~ol LM~-~5NX, a neutrallz~ uo~lum
~alt, which has a molecular weight of ~bout q,500 and A~ry~ol
LMW~20NX, a neutr~lized ~odlum ~alt, ~hich ha~ a molecular w~igh~
~ a
~ 131~213~ 1
¦ of about 2,000.
r ,~ A specific example of a polyacrylic acid copolymer that
can be used iY Sokalan CP5 5 from BASF) which has a molecular
weight of about 70,000 and i8 the reactlon product of about equal
mole3 of methacrylic acld and maleic anhydride which has been
completely neutralized to form the ~odium salt thereof.
The above polymers and copolymer~ can be m~de using
procedure~ known in the ar~c. See, for example, U.5. Patent
4, ~03, ~8 .
The water-soluble carboxyl group~containing bleach-
. stable polymers have been found to provide three primary
functlons ln the liquid automatic dishwa~her detergent compo-
sitiona of this inventions rheology control~ calcium
seque~tering~ and 80il digperBin9.
As a rheology control agent, the polymer additlve
apparently functlon~ as a thlckener and toge~her with the high
levels of alkali metal ~ilicate, clay ~when present) and fatty
acid or aalt (when pre~ent), to impart vi~coelasti~ity to the
composition and a plastic vi~co~lty in the range of from about
200 to lOjOOO centlpoise~ pr~ferably 2,000 to 8,000 cp~, ~uch a~
5,000 ~pB- The desired v~scoelasticity and pla~tic vi8c08ity
ranges are best achieved when the moleoular welght 1B no more
than 10,000, e~pecially from 2,000 to 10~000, ~uch as about 4,000
to 5,~00.
As ~ calcium ~equest~ring ayent lt i8 l~portant that
the polymer have e~peclally good wat~r solubillty. Here again,
be~t re~ults are achieved when the polymer has a molecular ~eight
of 10,000 or less, especially 2,00~ to 10,000.
Similarly as a 80il di~per~ing aqent contributing to
the deslrea i~p~oved antl-spottlng and anti-ilming properties,
~ 1'6~ P, P 6 ~ RJ~; 13
131~2~ ~
~- ~
~ol~cular weights of ~he polymer addltive are preferably in the
range of 2,000 to 10,000.
The amount of the polyacrylic acid polymer or copolymer
additive needed to achleve the de~ired enhancement of physical
S stabLlity and cleaning performance wlll depend on ~uch factors as
. the amount and nature of the fatty acld or salt (when pre~ent),
the nature and amount of ~he clay thickenee ~when present)~
detèrgent active compound, bleachlng agent, as well a~ the
anticipated storage and shipping condltion~.
Generally, however, amounts of the polyacrylic acid
polymer or copolymer additlve that can be u~ed are in the range
of from about 0.5 to 10~ by weight, preferably from about 0.80 to
8.0 w~ight percent, e~peclally preferably about 2 to 6 weight
p~rcent.
Detergent actlve material useful herein must be stable
in the presence of chlorine bleach, especially hypochlorlte
bleach, and tho~e o the organic anionic, amine oxide, phosphine
oxide, ~ulphoxid~ or betaine water di~per~lble surfactant type~
are prefexred, the firGt mentioned anionic~ being most preferred.
They ase used ln amount~ ranging from about 0.1 to 5%, preferably
about 0.3 to 2.0~. Paeticularly preferred surfactants herein are
th~ linear or branched ~lkali metal mono- and/or dl-(Cg-C143
alkyl diphenyl oxide mono and/or di~ulphates, eommercially
avallable for example as DOWFAX (registered trademark) 3n-2 and /
DO~FAX 2A-l. In general, the paraffin aulphonate~ tend to unduly
~ncrease viscosity causlng ~evere ~hearing force problems. In
. addition, the surfactant ~hould be compatible wlth the other
ingredlents o the compo~ition. Other ~ultable surfact~nts
include the primary alkylsulphakes, alkylsulphonates,
alkylaryl~ulphon~tes and sec.~alkyl~ulphates. ~xample~ include
~odium C~O-Cl8 alkyl~ulphate~, such as sodium dodecylsulphate and
sodlu~ tallow alcoholsulphate~ sodium Clo-Cl~ alkanesulphonate~,
~uch as soaium he~adecyl-l-sulphonate and ~odlum Cll-Clg alkyl-
benzene~ulphonate~, Ruch as sodium dodecylbenzenesulphonates.
S The corre~ponding potasslum ~alts may al~o be employed.
As other ~uitable surfactants or detergents, the amine
oxide ~urfaotants are typically of the ~tructure R2RlNO, ln
which ~ repre~ents a lowet alkyl group, for in~tance, methyl, and
Rl r~pr~ents a long chaln alkyl group having from 8 to 22 carbon
atom8, for in~tance, a lauryl, myri~tyl, palmityl or cetyl group.
Instead of an amine oxide, a coeresponding ~urf~ct~nt phosphine
oxide R2RlPO or sulphox~de RRlSO can be employed. Betalne
~urfactants are typically of the structure R~RlN - RnCOO-, in
which each R represents a lower alkylene group having from l to 5
carbon atoms. Speclflc example~ of these aurfactant~ are lauryl-
dimethylamine oxlde, myristyldimethylamlne o~ide, the corres-
ponding pho~phite oxide~ and ~ulphoxlde~, and the coreespondlng
betaine3, including dodecyldimethyla~monium acetate, tetradecyl-
dlethylammonium pentanoate, he~adecyldlmethylammonlum hexanoate
and the llke. For blodegradab~llty, the alkyl groups in the3e
surfactants ahould be l~near, and ~uch compounds are preferred.
Surfactant~ of the foregoing type, all well known in
tbe art, are deccribed, for example, in U.5. Patentc 3,9B~,668
and 4,271,030.
Although any shlorine bleach compound may be employed
in the compositions of thi~ lnvention, such as dichloro-
i~o~yanurate, d~chloro-dimethyl hydantoin, or chlorinated TSP,
alkali metal, e.g. potassiu~, lithium, ~agn~ium ~nd e~peoi~lly
sodium, hypochlorite is preerred. The compoeition should
contaln sufflcient chlorine bleach compound to pro~ida about 0.
~L3~2~
to 4.0~ by weight of available chlorlne, as determined, for
example, by acldiflcat~on of 100 parte of the compo~ltion with
exces~ hydrochlorlc acld. ~ ~olution contalning about 0.2 to
4.0% by weight of ~odlum hypochlorite contaln~ or provldes
rou~hly the same percentage of aYailable chlorlne. ~bout 0.8 to
1.6% by weight of available chlorine i~ e~pecially preferred.
For example, sodium hypochlorite (~aOCl) 301ution of from about
11 to about 13~ available chlorine ln amount~ of about 3 to 20%,
preferably about 7 to 12~, can be advantageously used.
The ~odium or potas~ium ili~ate, which provldes
alkalinity and protection of hard surfaces, such a~ fine chlna
glaze ~nd pattern, i~ normally employed i~ an amount ranging from
about 2.5 to 20 or 25 weight percent. At level~ gr~ater than
about 10 weight percent the ~ilicate al~o provides lncreased
anti-spotting actlon.
However, or the peeferred vl~coelastic, phy~ically
stable li~uid aqueous dishwa~her detergent compo~itions of this
invention lt is essential to incorporate quantitle~ of the alkall
metal slllcate ln exce~s o the amount~ normally employed,
e~pecially more than 25 weight percent, for example, from 28~ to
40~, especially from about 30 to 38S, by welght, of the
compo~ltion.
The sod~um ~illcate i8 generally added in the form of
an aqueous solutlon, preferably having an Na~OsBiOz rat~o of
abaut ls2.2 to 1:208, for example, ls2.4. Mo~t of the other
compon~nts of the compo~ition, especially NaOH, 60dlum hypo-
chlorite and foam depressant may al80 be added ln the form of an
aqueou~ dlsperBion or solution.
Foam inhibltion is lmportant to lncrease di~hwasher
machln~ efficiency and mlnlmize de~tabllizlng effects whlch mlght
1 16
~ ~31~2~3 ~
occur due to the presence of exce~ foam wlth~n the washer during
u~e~ Foa~ ~ay be ~ufflclently reduced by sultable selection of
the type and/or amount of detergent active materlal, the maln
foam-produclng component. The degree of oam i~ al80 ~omewhat
dependent on the hacdnes~ of ~he wash water ln the machine
whereby suitable adju~tment of the proportlons of NaTPP which ha~
a water ~oftening effect may aid in providlng the deslred degree
of fo~ inhibition. ~owever, it i~ generally pr~ferred to
include a chlorlne bleach ~table foam depre~sant or lnh~bitor.
Particularly effectlve ln thls regard, where some pho~phorus
content c~n be tolerated, are the alkyl pho~phonic acid e~ter~ of
the formula
O
lS HO- P - R
and ~pec~ally the alkyl acid phosphate e~tees of the formula
HO - P - OR.
OR
In th~ above formula~, one o~ both R groups ln ea~h type of e~ter
may repr~ent independently a Cl2-C20 ~lkyl group. The
ethoxylated derlvatlves of each type of ester, for example, the
condensat~on product~ of one mole of ester wlth from l to lO
mole~, preferably 2 to 6 moles, more preferably 3 or ~ molesr
ethylene oxide ~an al80 be u~Qd. Some examples of the foregoinq
are commerclally ~vailable, such ~ the product~ SAP fEom Hooker
and LPRn-1S8 from Knapsack. Mixtures of ths two types~ or any
other chlorine bleach ~table types, or mixtures o mono- and di-
esters of ~he ~ame type, may be employed. ~p~lally pr~rred .
18 a mixture of mono- and di-Cl6-Clg alkyl acld phosphate ester~
~uch as monostearyl/di~tearyl acld phosphates l.2/l, and the 3 to
4 mole ethylene oxide conden~at~ thereof. When employed,
proportion~ of O.Ol to 0.5 welght percent, prefer~bly 0.02 to 0.4
~3~
welght percent, especially about 0.1 to 0.2 welght percent, of
foa~ depre~sant in the compositlon i~ typlcal, the weight ratlo
o detergent active ~omponent to fo~m depressant generally
ranglng from abou~ 2~:1 to 4sl and preerably about 1~l1 to 5:1.
At these low level~ of the antl-foamlng agent, t~e total
pho~phoru~ content in the compo~ition wlll generally and
preferably be no more than O.Ol welght percent, b~ed on the
~otal compo~ltlon.
Wheee lt i~ de~lred to totally exclude pho~phorous any
of the known, bleach-compatlble ~llicone antl-foaming agents can
be used.
In the preferred thickened LADD compositions of thi~
invention, thickening i~ provided by inorganlc, water-~welling
collold-foeming clsys of smectite and/or attapulglte type~.
The~e mat~rials may generally be u~ed ln amount~ o~ about 0.1 to
10, preferably 1 to 5, weight percent, to confer the desired
propertie~. However, in the pre~ence of the fatty acid or fatty
acid metal salt stabilizers, les~er amount~ of the inorganlc
collold-forming clays of the smectlte and/or attapulglte type6
can be u~ed~ For example, amounts of cl~y in the range of ~rom
about 0.1 to 3%, preferably 0.1 to 2.5~, e~peclally 0,1 to 2%,
are g~ner~lly suff~cient to ach~eve the de~ir~d vlscoelastic
propert~e~ when u~ed in combinatlon wlth the f~tty acid (or fatty
asid ~alt) ~tabilizer, and other ~peclfied ingredlent~ D
Smectite clays include montmorillonlte ~bentonlte),
hectorite, attapulglte, ~mectite, ~aponite, ~nd the like.
Montmorillonlte ~lays are preferred and are avallable under
tradenames, ~uch as Thlxogel (regi~teeed trademark) No. 1 and
Gelwh~te ~cegi~tered trademark) GP, ~, etc., from Georgla ~aolln
Comp~nyS and ECCAGUM (reglst2red traaemark) GP, H, etc., from
~uthern Clay Product~. Attapulglte ~lay~ lnclude the mater~als
c~erclally avsllable under th2 tr~dena~e Attagel ~regl~tsr2d
@~ ~3~2~3 ~
trademark), i.e. Attagel 40, Attagel S0 and Attagel 150 from
Eng~lhard Minerals and Chemical~ Corporation. Mixtures of
smectlte and at~apulglte ~ypes in welght ratioa of 4~1 to 1:~ are
also useful herein. Thlckenlng or suspending agents of the
fsregolng type~ are well known in the art.
Physieal stability, iOe. eeslstance to phase 3epara-
tion~ settling, etc., of the~e liquid aqueous ADD compoaitions
can be slgn~ficantly lmproved by add~ng to the compositlon a
small but effec~ive a~ount of a long chaln fatty acid or a metal
~alt thereof. Actually, under the preferred alkaline pH
condltlon~ of the LADD GompositiOn~ viz~ pH 10.5 to 13.5, the
fatty acld~ will be converted to the corresponding alkali metal
~alts~
The preferred long chaln fatty acid~ are the hlgher
aliphatlc ~atty acids having from about ~ to about 22 carbon
atom~, more preferably from about 10 to 20 carbon atom~, and
especially preferably from about 12 to 18 earbon atom~, inclusive
of the carbon atom of the ~arboxyl group of the fatty acid. The
aliphatic radlcal may be saturated or unsaturated and may be
stralght or branched. Stralght chaln saturated fatty acids are
preferred. Mixture~ of fatty acid~ may be u3edt ~uch as those
deeived from natural ~ource~, ~uch a8 tallow fatty acld, coco
fatty acid, 80ya fatty acid, etc., or from ~ynthetic source~
avallable from industrial manufacturlng proces~e~. .
Thus, examples of the fatty ~cid~ include, for example,
decanoic acld, dodecanoic acid~ palmitic acld, myri~tic acld,
stearic acid, oleic acld, e~cosanolc acld~ tallow fatty acid,
coco ~atty acid, ~oya fatty acid, mixtures of the~e a~ide, ~tc.
Stearlc acld and mixed fatty acld~ ~re preferred.
The metal ~alts o the atty aclds may al~o be used and
any of mono~alent or polyvalent metals may be used. The mono-
19
131~
¦ valent metal include, or example, the alkali metal~,
¦ especlally ~odlum or pota~lum. Sodium 8alt8 ( soapsl are
¦ especially preferred
¦ The preferred polyvalent metals a~e the polyvalent
¦ metal~ of Groups ~IA, IIB and III~ of the Perlodic Table of the
Elements, ~uch as magnesium, calcium, aluminum and zlnc, although
other polyvalent metal~, lncludlng those of Groups IIIA, IVA, VA,
I~, IVB, VB~ VI3, YIIB and YIII of the Perlodlc Table of the
l Element~ ~an al80 be used. Specifi~ example~ of ~uch other
¦ polyvalent metals inalude Tl, Zr, V, Nb, Mn, Fe, Co, Ni, Cd, Sn,
Sb, ~i, etc. Generally, the metals may be present in the
dival~nt to pentavalent ~tate. Prefecably, the polyvalent metal
~alts are used in their higher oxidation ~tate~. Naturally, for
l LADD compo~ition~, as well a~ any other applicatlons where the
¦ invention compo~ltlon will or may come into sontact with
article~ u~ed for the handling, storage oe serving of food
product~ or whlch otherwi~e may come into contact w~th or be
consumed by people or animal~, the metal salt ~hould be selected
by taking into consideratlon the toxl~ity of the metal. For thi6
~0 ¦ purpose, the cal~ium and m~gne~ium salts are especially hlgher
preferred a~ generally ~afe food additlves.
Many oE these metal salts are commercially a~allable.
For example, the aluminum salts are available ln the triacid
form, e.g. aluminum ~tearat~ a~ aluminum tristearate, Al(C17-
~35C00)3. The monoacid ~alts, e.g. aluminum mono~tearate and
diacid salts, e.g. aluminum alstearat2, and mlxture~ of two or
three o the mono-, dl- and trlacld salts can be used for tho~e
metal~, e.g. Al, with valence~ of ~3, ~nd mlxtur2s o thn ~ono-
and dlacid ~alts can be used for tho~e metal~, e.g. Zn, wlth
valences o +2. It i8 mo~t preferred that the diacld~ of the ~2
I ~ 13182-~3
valent metal~ and the triacid~ of the ~3 valent metals, the
tet~ascid~ of the ~4 metals, and the pentaclds of the ~5 valent
metals~ be used ln predo~inant amounts.
The metal ~alts, a~ mentloned above, are generally
commerci~lly available but can be ea~ily produced by, for
example, saponification of a fatty acid, e.g. animal fat, ~tearlc
acld, etc., or the coeresponding atty acid ester~ followed by
treatment ~ith an hydroxide or oxide of the polyvalent metal, for
example, ln the case of the alumlnum salt, wlth alum, alumlna,
etc., or by reaction of a soluble metal salt wlth a soluble fatty
acid salt.
Calcium ~tearate, l.e. calcium disteflrate, magnesium
stearate, i.e. magnesium distearate, aluminum ~tearate, l.e.
aluminum tristearate and zlnc ~teaeate, i.e. zinc distearate,
are the preferred polyvalent fatty acid salt ~tabllizer~.
Mlxed ~atty acid~, ~uch as the naturally occurr~ng
acid~, e.g. coco acid, a~ well as mixed fatty acids resulting
from the commercial manufacturlng proce3s are al80 advantageously
u~ed as an inexpen~lve but effecti~e source o the long chain
fatty acid.
In addition, the dimer~ or tei~er~ of these acids can
also be u~ed.
The amount o~ the fatty acld or fatty acid ~alt
3tabllizers to achleve the de~ired enhancement of phy~ical
stabil~ty will depend on ~uch fa~tor~ ~8 the nature of the fatty
acid (or its ~alt), the nature and amount of the clay thickener,
det~rgent active compound, inorganic ~alt~, other LADD ingee-
d~en~s, a~ well as the anticlpated ~torage and shipping
conditions.
Generally, however, amount~ of the polyvalent metal
1 3 ~
fatty ~cid ~alt stabilizlng agents in the range oE from about
0.02 to l~t p~e~erab~y irom about 0.06 to 0.8~, especlally
preferably from about 0.08 to 0.4%, prov~de the long term
~tabllity and absence of phase separation upon ~tandlng or dur~ng
tran~port at both low ~nd elevated ~emperatures a~ are desired
~or a commercially acceptable product.
Although not wishing to be bound by any part~cular
theory a~ to the mode of operat1On of the fatty acid ~metal salt)
stabilizer~, lt i~ hypotheslzed that these stabilixers, whlch
under alkaline conditions, are anionic ~alts, lnteract with the
surface of the cationic ~lay part~le~ u~ed as the thickening
agent whereby the fatty acid moieties help to malntain ~he clay
part~cles in su~penslon. Furthermore, depending on the amounts,
proport~ons and type6 of phy~lcal qtabilizer~ and clay thick-
ener~, the addition of the fatty acid ~or lt~ ~alt) not onlyincrea~e~ phy~ical ~tability but also provide~ a simultaneous
increase in apparent viaco~lty. Ratio~ of fatty acid (~alt) to
clay thickener in the range of from about 0.08-0.4 weight percent
clay thickenlng agent are usually sufficient to provlde the~e
20 slmultan~ou~ benef it8 and, therefore, the use of these
ingred~ent~ in the~e ratio~ 1B mo~t preferred.
Generally, LADD efectiveness 1~ directly related to
~a) avallable chlorine level~s (b) alkallnityt (~) ~olubility in
washing ~edlu~5 and (d) foam Anhibltion. It i~ preferred herein
th~t the pH of the LADD compo~lt1On be at least ~bout 9.5, ~ore
preferably from about 10.5 to 13.5 and most preferably at least
about li.5. At the relat~vely lower pH value~, the LADD peoduct
i~ often t90 viscou3~ i.e. ~olld-llke, and thu~ not rsadily
~luidized under the ~hear-force levels crea~ed withln the
3~ d~spen~er cup under normal maehine operatlng condition~. In
131~2~
e~sence, the compo~ltlon lose~ much, if not all, of lta visco-
elastlc character. ~ddition of NaOH ~ thu~ often needed to
increase the p~ to withln the above range~, and to increa~e
flowability properties. The presence of carbonate i8 al80 often
needed hereln, since it ~cts as a buffec helplng to malntaln the
desired pH level. Exce~ carbonate ~ to be avolded, however,
. ~ince it may cause the foematlon of needle-llke cry~tals of
carbonate, thereby impairlng ~he stablllty, thixotropy and/or
detergency of the ~ADD product, ~B well a~ lmpairing the
di~pensab~lity of the product from, for example, squeeze tube
bottles. Caustlc soda ~NaOH) serves the further function of
neutralizlng the pho~phoric or phosphonic ac~d e~ter foam
depre~sant when present. About 0.5 to 3 welght percent of NaOH
and about 2 to 9 weight percent of sodium carbonate in the LADD
lS compo~ition are typical, although it ~hould be noted that
~u~ficient alkallnity may often be provided by the alkali metal
slllc~te.
The amount of water contained ln these composition~
should, of cour~e, be neithec 80 high A8 to produce unduly low
v~scosity and fluidlty, nor 80 low as to produce unduly hlgh
vi~co~lty and low flowab11ity, viscoela~tic properties in either
case being dimi~lshed or destroyed~ Such amount i~ readily
determlned by routine experlmentat~on ln any partlcular instance,
generally ranging from about 25 to 75 weight percent, preferably
about ~5 to 65 weight percent, in total, from all 80urces. The
. water ~hould al~o be preferably de~onlzed or 30ftened.
Other conventional ingredlents m~y be included in the~e
compositions in ~mall amounts, generally le~s than about 3 weight
p~rcent, such a~ perfume, hydrotropic agents, such a~ the sodium
ben~ene, toluene, xylene and cumene ~ulphonatea, preaeevatives,
23
3 ~31~
aye~tuffs and pigment~, and the llke, all, of course, being
stable to chlor~ne bleach compound and h~gh alkalinity
~properties of all the components). ~specially preferred for
coloring are the chlorinated phthalocyanine~ and poly~ulphides of
aluminosilicate which provide, respectively~ plea~ing green and
blue tlnts. Tio2 may be employed for whitenlng or neutralizing
off-shadeR. Abrasives or pollshlng agent~ should be avoided in
the ~A~D compositions a~ ~hey may mar the surface of flne
l d~hware, cry~tal and the like.
¦ According to one preferred method of maklng these
¦ compo~itions, one ~hould fir~t dissolve or di~perse all the
¦ inorganlo salt~, e.g. carbonate ~when ~mployed), ~licate and
¦ zeolite~ in the aqueou~ medium. Thlckening component9 includlng
¦ the carboxyl group containing polymer and clay (when present)
¦ aee added last. The foam depressor ~when employed1 is pre-
¦ llminar~ly proYided a8 an aqueou~ di~per~ion, as 18 the
¦ thickening agent. The foam depressant disperslon, ~austic soda
¦ ~when employed) and inorganic ~alts are first mixed at elevated
temperatures in aqueous ~olu~ion ~deioniz~d water) and,
th~reater, cooled, uslng agltatlon throughout. ~leach,
~uefactant, fatty acid ~or its metal salt stabillzer), polymer
and thlckener disper~ion at roo~ temperature are thereafter added
to the cooled ~25-35C) ~olution. ~xcluding ~he chlorine bleach
compound, total ~alt concentration (e.g. sodium ~licate and
carbonate) i8 generally about 20 to 50 weight percent, pre~erably
about 25 to 40 weight percent in the ¢omposltion.
. Another highly preferred method for mixing the
ingredient~ of the LADD for~ulation~ involves first formlng a
mixture of the ~ater, foa~ suppres~or, detergent, carboxyl group
containlng polymer, fatty acid or ~alt and clay. These
3~2~ ~
ingredient~ are mixed together under high shear conditlons,
preferably starting at room temperature, to form a uniform
di~perslon. To this premi~ed po~tlon, the remalning lngredlents
are introduced under low shear mlxing condl~ions. For lnstance,
S the required amount of the premix i8 lntroduced into a low ~hear
mix~r and thereafter the remainlng lngredients are ~dded, with
mixing, elther sequentially or simultaneously. Preerably, the
ngredients are added ~equentially~ although lt i~ not necessary
o complete the addition of all of one lngredient before
eginning to add the next lngredlent. Furthermore, one or more
f the ingredients can be divlded lnto portion~ and added at
lfferent time~. Good results have been obtained by adding the
emaining ingredients in the following ~equences sodium
ydroxide, alkali metal carbonate, sodium sillcate, alumino-
ilicate zeolite, bleach ~preferably, ~odlum hypochlorite) andodium hydroxide.
The llquid ADD compositions of this invention are
eadily employed in known manner for wa~hing dlshe~, other
itchen utensils and the like in an automatic dishwasher,
rovided with a ~uitable detergent dispenser, ln an agueous wash
ath containing an effective amount of the compo~lt10n.
While the invention ha~ been particularly described in
onnection with its appllcation to ll~uld automatic diahwasher
etergents it wlll be readily understood by one of ordinary sk~ll
n the art that wlth or without the beneflts of viscoelasticity
nd phy~ical stability which are obtained by the additional
mounts of the alkali metal silicate and by the interaction of
he clay and the fatty ~cid, the cleaning benefits provided by
he combination ~f bleach stable detergent, bleach, ~nd zeolite
~uilder and bleach-stable, water-~oluble carboxyl gr~up
~31~2~.~3
e~ ~3
containing polymer make the compositions of thi~ invention useful
a~ a gener~l type liquid cleaning compo~ltlon for di~he~, gla~-
ware, cutlery, pot~, pan~ and the like.
The cleanlng performance, in terms of removal of a
broad spectrum o~ fooa ~tains, of the inventlon composition ls
comparable or slightly superior to that of similar alkali metal
polypho~phate, e.g. ~odium trlpolyphosphate bullt detergents.
For in~tance, in cleaning test~ again~t various food re~ldues,
¦ some of whlch were baked on, lncludlng egg, peanut butter, tea,
¦ coffee, milk, chocolate ~ilk, tomato ~ulce, rice, rice/chee~e
¦ mixture, whlte sauce, oatmeal and spinach, the lnvention LADD
¦ composition achleved ~llghtly better cleaning or the ~ame
¦ cleanlng for 14 to 16 food stains on various ~ub~trates (gla88eg r
¦ cup8, cutlery, plates, pot~) and only slightly worse for
¦ chocolate mllk and baked rice on pot~.
¦ Furthermore, as will be shown ln the example to follow,
¦ the composltlons of thls lnventlon are generally superlor to
¦ si~ilar phosphate bullt compositions in terms of spottlng and
¦ ilm formatlon.
¦ The lnventlon may be put lnto practice in various ways
¦ and a number of specific embodiments have been described to
¦ lllu~trate the invention with ref erence to the accompanylng
example.
l All amount~ and proportions referred to herein are by
2S ¦ weight of the composition unles~ otherwise lndicated.
I !~
¦ The following two compositlon~ are prepared in order
to compare the properties of the inventlon compositlon with a
similar pho~phat~ built compositlon
~3~ g~3
Invention Compari~on
Component Run No. 1 Run No. 2
Water, deionized 16~44 30.44
Stearlc ac~d 0.10 0.10
S~ec~ite ~lay tVan Gel ES) 1O50 1.50
Sodlum Silicate (47.5~
solution of Na2:si~2
ratlo of ls2.~) 35.00 25.00
Sodium trlpolypho~phate
(substantlally anhydroua,
i.e. about 3~ moisture) ~ 12.00
Sodium tripolypho~phate
hexahydrate ~ 12.00
1~ Aluminosili~ate zeollte 24.00
Sodium c~rbonate, anhydrou~ 6.00 6.00
Sodium hypochlorlte~
(1~ available ch~orine) 9.00 9.00
Surfactant ~Dowfa~B-2,
45% Na mono- and di-decyl
dlsulfonate-aqueous
solution) 0.~0 0.80
Antifoaming agent
~Knapsaa~ LP~n 158,
mixture of mono- and
dl-~tearYl (C16-C18)
alkyl e~ter~ of
phosphor~c acid, mole
ratio about 1 s 1. 3 0 .16 0 .16
Cau8tic ~oda solutlon
(50~ NaOH) 3.00 3.00
Sodium polyacrylate
~MW~4,500)(45S ~olutlon) 4.00 -----
100 .00 100 .00
Each of the formulation~ of Runs 1 and 2 are teated to
compare cleaning performance (buildup of spots and fllm~ on
gla~sware) u3ing a ~enmore~d~hwaaher with 100 gram glassware
using ~p water temperature at 130F and 120 ppm hardness. The
teut procedure i8 de~crlbed in ASTM D3566-79, except that only
four cleaning cycle~ a~e u~ed. The filmlng and spotting are
2valuated according to the follow~ng ~caless
27
~3~3~3~
. ~ ~_,
Fllm Rating ~cale
1. Best, no apparent fll~
2. Filming slight, becoming apparent
3. Noticeable film, increa~ing
4. Continued increase o~ slgnificant fllm
5. Filming becoming excessive
_ 6. Filming high, exceBsive buildup
¦ 7. Continued increase of e%~es~ive film.
¦ Spot Ra~ing Scale
0 ¦ A. Be~t - no 8pot~
¦ B. Very few spots apparent
¦ C- Di8tinct
¦ D. Significant coverage approximately 50~.
¦ The results ~re ~hown belows
15 ¦ Perform~nce Ratin~
¦ Spot~ Films
¦ Cycle ~ Run 1 Run 2 Run 1 Run 2
20 1 1 A,~ a 1,2 1,2
2 A,B B 1~2 1,2
l 3 A,B-a B-C 1,2 1,2.
25 ¦ ~ B B-C 2 2
Simllar results to tho~e de~cribed abov~ will be obtained lf the
polyacrylate i~ replaced by methacryl~c acid/maleic anhydride
copolymer, e.g. Sokolan CP50
