Note: Descriptions are shown in the official language in which they were submitted.
- 1318 2 ~ ~
THIXOTROPIC AQ[1130US LIQUID AUTOMATIC
DISHWASHING DETERC;ENT COMPOSITION
FIELD OF THE INVENTION
The pre~ent invention relateg to a thi~co~ropic aqueous liquid automatic
dishwashing detergent composition with improved anti-filming properties and
method of using ~he detergent compoaition to clean slishware, glas~war2,
chin~ snd the like. The dishwashing composition cont~ns ~ilica, as the
anti-filming agent, inorganic builder s~lts, chlorine bleach ) bleach stable
detergent and a thixotropic thickener.
The detergent dishwa~hing compogition of the present invention
reduced filming on dishware, glassware, china and the like, particularly in
hard water, and remains stable against phase sep~ration.
More specifically, the invention relates to the u~e of silica as an
anti-filming agent in thlxotropic aqueous liquid dishwa~hing detergent
compositions to reduce filming.
The detergent compositions do no require an added rinse aid, are
stable in ~torage, do not settle and are readily redispersible and are
pourbble.
The present invention al80 relate~ to thixotropic aqueous suspension
with improved physical stabi~ty. The invention relates to the use of long
chain f~tty acids, metal salts of fatty acids and clay as thixotropi~ agents
for forming ~table gel-l~e liquid ~uspensions suitable for use as liquid
automatic dishwasher detergent composition.
The present invention ~pecifically relates to aqueoua liquid automatic
dishwashing detergent compositions hsving thixotropic propertie~, improved
anti filming and physical stability lpropertie~, which are readily dispersible
3 ~ 3 ~
in the s~r~shing medium to provide effective cleaning of dishware, glassware,
china and the like.
PRIOR ART
Commerci~lly available household-m~chine dishwasher detergents
provided in powder form have gevergl disadvantages, e. g. non-uni~orm
composition; c08tly operation~ necessary in their manufacture; tendency to
cake in storage at high humidities, resulting in the formation of lumps
which are difficult to disperse; dugt~nesg, a source of particular irritation
to users who suffer allergies; and tendency ~o cake in the dishwasher
machine dispenser. Liquid forms of dighwaghing compositions, however,
generally cannot be used in automatic dighwashers due to high fosm levels,
unacceptably low vlscosities and exceedingly high alkalinity.
In addition, the pregently u6ed formulated powder detergentQ
frequently require a 3eparate ~tep of hand towel wiping and drying of the
dishware, glE~ssware, china and the like to avoid leaving undesirable traces
or film of precipitated calcium and magnegium salts. The use of liquid
detergent compositions present other problems. The builder salts settle in
storage and are not readily redisperged. The compositions 8180 frequently
become thicker in storage ~nd are not readily pourable.
Psecerlt research and development ac~ivity ha~ focu~ed on the gel or
~thixotropic" orm of quch compo~itions, however, such compositions have
generally proven to be insufficiently Vi8CoU8 to remain "anchored" in the
dispen~er cup of the dishwasher, and moreover yield spotty residues on
dishware 9 glas~ware, china and the like . Ideally, thixotropic deansing
compoæitions should be highly Vi8CoUs in a quiescent state, Bingham plastlc
in nalture, and have relati~ely high yield values. When subjected to shear
stresses, however, such as being shaken in a container or squeezed
through an orifice, they should quickly fluidi~e and, upon cessation of the
pplied shear strsss, quickly revert to the high ~iscosity/Bingham plastic
~ 1 3 ~
~tate . Sta~ility is likewise of primary importance, i . e . there should be no
signiricant evidence of phase separation or leaking after long standing.
For effective use, it is generally recommended that the automatic
dishwashing detergent, hereinafter al80 designated ADI~, contain (1) sodium
tripolyphosphate (NaTPP) to goften c-r tie up h~rd-wa~er minerals and to
emulsify and/or peptize 80il; ~2) fiodium 6ilicate to supply the alkalinity
necessary for effective detergency and to provide protection for fine china
glaze and pattern; (3) sodium carbonate, generally considered to be
optional, to enhance alkalinity; (4) a chlorine-releasing agent to aid in the
elimination of soil 6pecks which lead to water spotting; and (53
defoamerl surfactant to reduce foam, thereby enhancing machine efficiency
and supplying requisite detergency. See, for example, SDA Detergents in
Depth, "Formulations Aspects of machine Dishwashing," Thomas Oberle
(1974), Cleanserg approximEIting to the afore-described compositions are
mostly liquids or powders. Generally, such compositlons omi~ hypochlorite
bleach, since it tends to react with other chemically active ingredients,
particularly surfactant, thereby degrading the suspending or thixotropic
agent and impairing its effectiveness.
Thus, U . S . Patent No, 3, 985, 668 deecribes abrasive 8COU~lg cleaners
of gel-like consistency containing (1~ suspending agent, preferably the
Smectite and attapulgite ~ype~ of clay; ~a) abrssive) e.g. ~ilica sand or
perlite; and (3~ filler compri~ing light density powdered polymers,
exp~nded perlite and the like, which has a bouyancy and thus stsbili~ing
effect on the composition in addition to ser~mlg as a bulklng agent, thereby
replacing water otherwise available for unde~ired supernatant layer
formation due to leaking and pha3e destabilization. The foregoing are the
essential ingredient~. Option~l ingredient~ include hypochlorite b1each,
bleach stable surfactant and buffer, e.g. silicate~, carbonates, and
monophosphates. Builders, such as NaTPP, can bs Included as further
optional ingredients to supply or aupplernerlt builMng function not provided
:
1 3
by the buffer, the amount of guch builder not exceeding 5% of the total
composition, according to the patent. Mg~ntenance of the desired (greater
than) pH 10 levels i8 achieved by the buffer/builder components. High pH
. i8 s~id to minimize decomposition of chlorine bleach and undesired
interaction between surfgctant and bleach. When present, NaTPP i8 limited
to 5%, as stated. Foam killer is not disclosed.
A In U.K. Patent Application GB 2,116,199A and GB a,l40,450A, both of
which are assigned to C:olgate-Palmolive, liquid ADD compositions are
disclosed which h~ve propertieg desirably charac~erizing thixotropic,
10 gel-type structure and which include each of the Yarious ingredients
necessary for effective detergency with an automatic dishwasher. Th~
normally g~l-like aqueous automatic dishwasher detergent composition hsving
thixotropic properties include~ the following ingredients, on a weight basis:
(a) S to 35% alkali metal tripolyphosphate;
(b) 2.5 to 20% sodium silicate;
(c) O to 9% alkali metal carbonate;
(d) 0.1 to 5% chlorine bleach stable, water dispersible organic
detergent active material;
(e) 0 to 5% chlorine bleach stable foam depres~ant;
(f) chlorine bleash compound in an amount to prosride about 0.2
to 496 of available chlorine;
~g) thi~cotropic thickener in an amount suffi~ent to provide the
compo~ition with thixotropy index of about 2.5 to 10; nnd
(h~ sodium hydroxide, a~ nece~sary, to adju~t pH.
ADD compositions so formulated are low-fo~ming; ~re readily soluble in
~he washing medium and most effective at pH value~ best conducivs to
improved cleaning performance, viz, pH 10 . 5-13 . 5 . The eompositions are
normally of gel con~istency, i.e. a highly viscous, opaque ielly-like material
having Bingham plastic character and thus relatively high yield values.
Accordingly, a definite shear force i8 nece~sary to inltiatc or insrease flow,
~ 7'A~oe,n~
. 1~2~ 6230l-l508
SUCJl ng ~vould obllln wllllin tll~ ngltatc l dlt1petlser cup Or nn energlzed
~ulornalic dishwnsher. Under 8uch colldltlon~ the compo~ltlon 19 qulckly
~lukllzed ond eusily dlgp~r9ed Wllen ~e E~hear force 18 dJscontlt)ued the
. lluld compo~i~lon qulckly reverta to fl hlg~l visco~lty Blnghum plastle state
closely npproximrlllng il~ prior con~lsteney.
U.S. Putent 4 511 487 dnted l~prll 1ff I9a5 deserlbes a low-~o~mlng
detergent pasle ror dl~ wn~llerD~ T~le compo91~10n 18 bnsed on u mlxlure o~
rinely dlvldetl hydru~ed ~odlum metuglllcllte nn aetlve ehlorlne compound
~nd u tlllckenlng ugen~ wlllcll 19 U rollUtc~l alllCDte of ihe hectorlte type.
10 Small amount of nonlonlc ~enBlde8 nnd aiknil me~ul ellrbon~tes nnd/or
hydroxldel3 mlly be used.
~ relnted copencllllg Canadian application which is assigned to
the common assignee is Serial No. 526,708, ~iled January 6th,
1987. The copending ~pplication
1~ dlscloyes ~hlxotropic nqueoug automalle dlghwaghlng detergent composlllon
wlllch eonlulns a long elluln rat~y neld ag u ~hlxo~rople tlllekener agenl.
~~DVI~NT/~GES OVEII TIIE PnlOn AnT
The llllxolroplc uqueou~ llqul i detereellt compogltlons Or llle present
Invention overcome many of t11e prlor urt problems ~aswlnted wilh powder
20 nnd llquld detergent~. Beenu~e Or the uddltlon Or n emnll effeetlve amounl
of n ~IIIeu unll-fiimlng agent to the eompogl~lon an added rlnse ~Id 1~ nol
requlred nnd towel wlplng and drying are not requlred to oblaln dry
~purkllng eleDn dlshes gla~se~ eup~ nnd eatlng utenslla. Tho lhlxolrople
uqueous llquid detergenl compoYl~lon ha~ the addltionai lldvnntllge~ of belng
25 stuble non-uettllng in storage und reudlly redl~perslble. The liquld
cOmpO9ltlon8 Or lhe pre~ent invenllon ure euelly pourQble eRully meu~ured
. nnd ea~lly put into the dlshwn~lling muehlnes.
~\n ndditionul und unexpeeted udvuntnge Or udding the u(llc
untl-fiimlng ngent to the detergerlt ~ormulullon 1~ that the ~IIIea inhlblt~
30 brown stnin rormutlon In the dlsl-wuE3hlng muehlne. The brown ~t~ln la
,~
' ~.'
~ 62301-150~
rormed by the (lepo~ltioll In the dlahwual~lng mnchlne Or Iron llnd/or
mnngnnese oxldee. Tl~e brown ~tnJn formntlorl in n pnrtlculorly ~orlou~
probiclll In nrens hnvi~ nrd waler. Tl~a ~IIIcn In tlle rormulnllon nct~ Ol1
. the Iron nnd/or mangnne8e In the wn8h wn~er to prevent thelr depoltlon In
lhe dlnllwnslling m~chine ng Iron nnd/or mnngnneRe oxldes.
AIMS Ol~ Tll~ SENT IMVENTION
The present invention seeks to provide a thixotropic
ngueoun llquld nutomallc clisllwns~ler detergen~ componltlon th~t h~n ~mproved
untl~rllmlng propertlea.
The invention also seeks to provide a thixotropic aqueous
liquld cletergent compo~lllon whlch IR n/nble ~n ~tornge, enslly pournble nnd
readlly dispersil~le In the dlsl-wnslllng wnter.
'rhe invention also seeks to provide a method of washing
dl~)lwnre, glnRswnre, chlnn nnd the llke In nn nutoma~le dl~hwneh~ng
muchlne uelng n thlxo~roplc nqueoua llquld detergent compoDltlon In whlcll n
sepnrnte rlnce nkl In not ndded or needed~
'l'he invention also seeks to provide a method of
w~shlng dl~hwnre, glna6wnre chlnn And lhe llke in nn nutomntle washlng
mnchlne unlng nn nqueoun llquld detergent eomponltlon by wlllch method tlle
dlshw~lre, gloa~wnre, ehlnn ~nd the llke nre mnehlne drled wlthout ienvlng
trncee or 1I fllm.
This invention further seeks to provide stable aqueous
tlllxotroplc nqucoun llquld composltlonn, enpaclnlly ~ulornnlle dln!lwnnher
detergent composltlona by Incorporllting In tlle ~queoug ~uapen81On ~ 6m~11
efrecllve nmount of n ~IIIcn nntl-fllmlrlg ngent. Therc In ~ O ndded n mlnor
nmount of ~ rlltty ocld metnl ~nlt of ~ ~tty ncld nnd/or clny thlxotroplc
thlckener effecllve to Inhlblt the ~ettllng of the su~pended pArllcles ansl to
prevent phnse nepnrtltion.
1 3 ~ ~ 2 ~ ~ 62301-1508
DETAILED DESCRIPTION OF THE INVENTION
The lnventlon will become more readlly understood
from the followlng detailed descrlptlon of the lnventlon and
preferred embodiments thereof which relate to lncorporatlng ln
an aqueous llquld detergent compositlon a small but effectlve
amount of a slllca anti-fllmlng agent. The lnventlon provldes
a gel-llke thlxotropic aqueous llquld automatlc dlshwashlng
detergent composltlon comprising water, organlc detergent, at
least one lngredient selected from th~ group conslstlng of
bleach, detergent builder, sequesterlng ayent, foam lnhlbltors,
and mlxtures thereof, from about 0 5 to 5% of a slllca antl-
filmlng agent and a sufficlent amount o~ a thlxotroplc
thlckener to provlde a thlxotroplc lndex of about 2.5 to 10.
The physlcal stablllty of the composltion ls lmproved by the
addltlon of a fatty acld, metal salt of a fatty acld and/or
clay thlxotropic thlckener. The slllca antl-fllmlng agent
preferably has a partlcle slze of about 0.1 to 10 microns. In
a preferred embodiment of the lnventlon there ls added to the
compositlon a sufflclent amount of a long chaln fatty acld or
metal salt of a long chain fatty acld, or elther of the
foregolng ln admlxture wlth a clay thlxotroplc thlckener to
provlde a thlxotropic lndex of about 2.5 to 10 and to inhlbit
settllng of the suspended partlcles, such as alkall metal
bullder salts, etc.
In accordance wlth this aspect, the present lnvention
provldes a normally gel-llke aqueous llquld automatlc
dishwasher detergent composltlon havlng thlxotropic propertles
whlch lncludes, on a weight basis
(a) 5 to 35% alkall metal trlpolyphosphate;
(b) 2.5 to 40~ sodium slllcate;
(c) 0.5 to 5% slllca antl-filmlng agent;
'~
~3~2 ~ ~
62301-1508
(d) 0 to 9 ~ alkali metal carbonate;
~ e) 0.1 to 5% chlorine bleach stable, water dispersible
organic deteryent active material;
(f) 0 to 5% chlorine bleach stable foam depressant;
~ y) chlorine bleach compound in an amount to provide
about 0.2 to 4% of available chlorine;
7a
A
~
(h) thixotropic thickener in an amount ~ufficient to provide a
thixotropic index of about 2.5 to lO.
(i) O to 8% ~odium hydroxide; and
(j) ba~ance water.
Also related to thig gpeciflc a~pect, the invention provides ~ method
for cleaning dishware in an automat~c dighwaghing machine wi~h an aqueous
wash bath containing an effective amount of the liquld automatic dishwasher
detergent (LADD,) composition ag de3cribed above. According to this aspect
of the invention, the LADD composition s~an be readily poured into the
di~pensing cup of the automatic dighwashing machine and will, within just a
few second~, promptly thicken to its normal gel-like or pasty state to
remain securely within the dispensing cup until shear forces are again
applied thereto, such as by the water ~pray from the dishwa~hing machine.
The invent~on will now be descrlbed in grester detail by way of
1~ specific embadiments thereof.
The LADD products of for example the prior disclosure in the
aforementioned aB 2 ,11B ,199A and GB 2 ,140, 450A exhibit rheologica
properties as evaluated by testing product vi~cosity a8 ~ function of shear
rate. The composiffons exhibited higher v~cosity at a low shear rate and
lower viscosity at a high shear rate, the data lndicating efficient
fluidization and gellation well within the shear rates extant within the
st~ndard dishwasher machine. In practical terms, thi~ means improved
pouring and processing eharacte~tics A8 well a~ le88 leaking in the
machine dispenser-cup, compared to prior liquid or gel ADD producls. For
applied sheur rates corresponding to 3 to 30 rpm, vlscosities (Brook~ield)
correspondingly ranged from about 10~000 to 30,000 eps to about 3,DOU to
7, 000 cps, a~ measured at room temperature by mean~ of an LVT Brcokfield
~scometer ~fter 3 minutes using a No. 4 spindle. A shear rate of 7.4
sec 1 corresponds to a splndle rpm of about 3. An appro~mate 10-fold
increase in shear rate produces about a 3- to 9-fold reduction in visco~ity.
~ . ~
1 31 8 h ~ ~
The composi~ions of the assignee~s prior invention thus exhibit threshold
fluidizations at lower shear rateg and of E;igniffcantly greater extent in
. terms of incremental increaseg in shear r~te vergus incremental decrease in
viscosity~ This property of the LADD products of the prior inventlon is
summarized in termg of a thixotropic index (TI) which iB the ratio of the
apparent viscosity at 3 rpm and at 30 rpm. The prior compositions have a
Tl of from 2 ~o 10, The LADD compositions 8hould exhibit substantial and
quick return to pFior quiescent 8tate con8istency when the shear force is
discontinued.
In terms of apparent viscog~ty, it has been ascertained that 80 long as
the viscosity at room temperature (22+1C~ measured in a Brookfield
Viscosimeter HATD, using a number 4 spindle at 20 rpm, ~8 less than about
20, 000 cps, the composition can be readily ~haken so that a thixotropic
composition can be easily "fluidized" or nliqueffed" to allow the product to
be dispensed through a conventional ~queeze tube bottle or other
convenient dispenser.
The present invention is based upon the surprising discovery that
substantially improved anti-filming propertieR can be obtained by adding to
the thixotropic aqueous liquid detergent composition a small effective amount
of a silica anti-filming sgent. The physical stability, i.e., resistance to
phase sepsration, settling, etc. can be achieved by adding to the
composition a smsll e~fective amount of a thixotropie thickener and
stabilizing agent.
ANTI-FILMING AGENTS
The ~ilica snti-filming agent materials tha$ can be used are fumed or
precipitated synthetic or natural silica. The silica may be amorphouR or
crystalline.
The 8ilica material that is UAcled may contain up to about ~.1 to 59
alumina (A1203), usually up to about 0.5 to 3% and more u~ually a~out 1
alumina, based on the weight s)f silica.
~ 1 3 ~
:`-
~b A preferred ~lica material i8 Syloid 244 which i8 amorphous 8ilic~, has
a particle si~e of ,~bout 4 ~ icrons and is proqided by W ~ R . Grace Co~
Another ~uitsble silica material is Silox ~5, also from W, R . Grace Co.,
which has a particle size of about 4 microns~
Another preferred silica material i8 Huber Zeo 49 which i8 amorphous
silica and i9 provided by J . M . Huber Corporation and cont~ns about 1%
alumina (Al203). The presence of as little as 1% A1203 i8 found to help
reduce the hydrolyE;is and subgequent golubility of the silica in the highly
alkaline automatic dishwashing detergent composition.
The particle size of the ~ilica m~lterial that ig u~ed iB important in
achieving the desired anti-filming properties.
The silica particles that are used are finely divided and can have a
particle size ~f about O .10 to 10 microns, preferably O . 50 to 8 microns and
more preferably ~bout 1. 0 to 5 . O microns . The silica pQrticles of this size
and the amount used herein are not abrasive.
The finely divided silica material p~rticle~ in the dishwashing wash act
to coagulate proteinaceous particulate 80ilE~ and keep~ them in suspension to
prevent them from depositing on the clean glas~ and dishware.
The amount of silica anti-filming agent that can be u~ed to achi~ve the
desired improvement in film will depend on the hardnes~ OI the water,
detergent active compound, lnorganic salts ~nd other Al~D ingredients.
The ~ilica anti-filming agent is particularly effective in hard wash water of,
for example, 300 ppm hardness or more.
The amount of sil~ca anti-f~lm agent that is used can be about O . 5 to
5%, preferRbly about 1 to 4% and more preferably about 1.5 to 3% by weight
based on the weight of the entire composition.
THIXOTROPIC THICKENERS
_ ~ _
The thixotropic thi~keners or ~uspending ag~nt~ that can be used. in
accordance with the present invention to provlde the Aqueous medium with
thixotropic properties may be organlc, for example, fatty acid or fatty acid
* ~a~r~ A~ 10
:. I o
1 13~2
polyvalent metal salts or inorganic colloid forming clay materisl~. The
thixotropic thickerlers should be 8table to high alkalinity and ~table to
chlorine bleach s~ompo~nd~ such a~ sodium hypochlolqte. The preferred
thixotropic thickeners comprise the fatty acids, the fatty ~cid polyvalent
metal salts and ~he inorganic, colloid-forming clay~ of smectite and/or
attapulgite typeg. The amount of the thixo~ropic thickener used will
depend on the particular thicke~er used, but gufficient thickener i8 added
to the formulation to provide the compo~ition with a thixotropy index of
about 2.5 to 10.
10 ¦ The preferred fatty acid thixotropic thickeners are the higher aliphatic
fatty monocarboxylic acids ha~ing from about 8 to about 22 carbon atoms ~
more preferably from about 10 to 20 carbon atomg, and especially preferably
from about 12 to 18 carbon atomg, inclusive of the carbon atom of the
carboxyl group of t~le fatty acid. The ~iphatic radical may be saturated or
unsaturated and may be straight or branched. Straight chain saturated
fatty acids are preferred. Mixtureg of fatty ~cids may be used, such a~
those derived from natural gourceg, ~uch ~,8 tallow fatty acid, coco fatty
acid soya fatty acid etc or from synthetic sources av~ilable from
industrial manufacturing processe~
20 ¦ Thus, ex~mples of ~he fatty acidg which can be used as thickeners
include, for example, decanoic acid, lauric acid, dodec~oic acid, p01mitic
acid, mylqstic acid, stearic acid, oleic acid, eico~anoic acid, t~llow îatty
acid, coco fatty acid, soya fatty acid and mixtures of these acid~. Stearic
acid and mixed fatty acid~, e.g. coco fatty acid, are preferred.
25 ¦ The amount of the fatty tlci~ thickener to achieve the desired value~ of
thixotropy and physical stE~bili$y w~l depend on such factors a~ the nature
of the fatty acid, detergent active compound, inorganic 881t8, eqpeCiEllly
TPP, other LADD ingredients, ~s well 88 the anticipated storage and
shipping conditions.
Il I
2 ~ ~
- 62301-1508
Cenernlly however nmounts ot tlle fntty nclcl thlxotroplc ngenl tllnl
car~ be used are In the runge of from uboul 0.~3 to 0.5~ preterobly from
nboul 0.0~ lo 0.2~ egpccinl]y plc~crnl~ly rrom nlloul 0.05 lo 0.15~ provklc
the de31red lvng term ~tnbillty nnd absence of phQse 6eparnllon.
The polyvnlent metnl gnlt~ of lhe above fn~ty ncld~ can al~o be used in
the present Invenllon u~ thlxotropic thlckcner aE~entu. Sullable mclnl soll
tllixotroplc thickenerg nre dl8clo~ed In Canadi~n Dppllcallon Serlal No.
~46 121 flle~l Scplcmbcr 4th 1987.
The prererred metulg nre the polyv~lent metnlg guch na mugneslum
calclum nlumlnum und zlnc.
Generully the metnls muy be pregent 1s~ the dlvalent to ~entavnlent
stute. Prefernbly the rmelnl 0nlts ure usetl In thelr hlgller oxi(lnllon 6tntes.Nulurully for L~DU compo~lllons ns well n~ uny olhcr appllcnllonn whcrc
the Inventlon composltlotl wlll or mny comq Into contact wlth nrtlcles u~e~l
ror the hundllng storuge or serv~ng of food products or whlch otherwl~e
muy come into contuct wlth or be consumed by people or ~nlmnls lhe metnl
snlt should be selected by tnkJnF Into conslclerntlon the toxlclty of the
metnl. ~or thi3 purpo~e the calclum und mugneslum sults are especlnlly
Illghly preferred o~ gencrnlly sufe rood ad(lillve~.
Mnny of these metnl ~ulls ure commerclnlly uvnllablq. For example the
nlumlnum 6alts are nvnilnble in llle trl~lcld form e. g. nlumlnum ~teurute us
nlumlnum tristeurate Al(C17-1135C00) ~. Th~ mononcld 0ults e.~. nlumlnum
1(0~1)2(C171-13$C00) nnd d5acld sDlt~, e g nlumlnum
2S dlslearute Al(O~l)C1711~5C00)2 und mlxlures Or two or three of the
mono~ und tr~ncld 8~l8 cun be u~ed f r ~ho~e metalu e. g. Al wllh
vulences Or +~ untl mlxlures of tlle mono- and dlocid snlt~ can be used ~or
tho6e metnls e. g. Zn Witll vnlences Or ~2 It 18 more preferred that the
dlnclds o~ the +Z vnlent metul~ and llle trlnclds Or the +3 valenl metuln the
tetraucld~ Or the ~4 melnls ~nd the pentnclds of the ~ vnlent melnl~ be
Il A 18
h "
`:~
131~2
used in predominant amounts. For example, at leagt 30%, preferably at
least 50~, especially prefer{lbly from 80 to 100% of the totsl metal salt shouldbe in the highest possible oxid8tion gtate, i.e. each of the possible valence
sites i8 occupied by a ~atty ~cid re~idue.
The metal salts, a9 mentioned above, are generally commerci~lly
available but can be easily produced by, ~or example, ~aponification of a
fatty acid, e. g. animal fat, gtearic acid, etc., or the corresponding fatty
acid ester, fol~owed by tre~tment With an hydroxide or oxide of the
poly~alent metal9 for example, in the case of the alwninum a~lt, wlth alum,
alumina, etc.
Calcium stearate, i . e . calcium distearate, magnesium stearate ~ i . e .
magnesium distearate, aluminum stearate, i.e. aluminum tristearate, and zinc
stearate, i. e. zinc distearnte, are the preferred polyv~lent fatty acid s~lt
stabilizers. Mixed futty acid metal salts, guch as the naturally occurring
acids, e.g. coco acid, as well ag mixed fat~y acids resulting from the
commercial manufacturing process are al~o advantageously used as an
inexpensive but effective source of the long chsin fatty acid.
The amount of the fatty acid galt gtabili~erg to achieve the desired
enhancement of phy~ical stability will depend on such factors aB the nature
of the fatty acid salt, the nature and amount of the thixotropic agent,
detergent active compound, inorganic saltg, egpecially TPP, other LADD
ingredients, as well a6 the anticipated storage ~nd shipping conditions.
Generally, however, amount~ of ~he polyvalent metal ~atty acid salt
stabilizing agents in the range of from about 0.02 to 1%, preferably from
2 5 about 0 . 06 to 0 . 8%, especially preferably from about 0 . 08 to 0 . d,%, provide
the long term stability and absence of pha6e #eparation upon standing or
during tran~port at both low and elevated temperE~tures as are required for
a commercially acceptable product.
There may alBO be used in the pregent invention the convention~l
30 inorganic thixotropic clay thickeners. The clay thickeners may be used in
' I ~ ~
- 1 ~3~
smali amounts in combination with the fatty acid thickeners or in
¦ combination with fatty acid polyvalent metal salt thickeners. The clay
¦ thickeners, howeYer, may ~e used by themRelves as the thixotropic
¦ thickeners .
The preferred clay thickeners compri~e the inorganic, colloid forming
cl~ys of smectite and/or ~ttapulgite types.
Smectite clays include montmorlllonite (bentonite), hectorite,
attapulgite, smectite, saponite, and the like. Montmorillonite clay~ are
preferred 0nd are available under tradename~ such a~ Thixogel (Registered
Trademark) No. 1 and Celwhite (Regigtered Trademark) GP, H, etc., from
Georgia Kaolin Company; and Eccagum (Registered Trademark) GP,, H, etc.,
from Luthern Clay Product~. Attapulgite clays include the materials
commercially av~ilable under the tradename Attagel (Registered Trademark),
i. e . Attagel 40, Attagel 50 and Attagel 150 from Engelhard Mineral~ and
Chemicals Corporation. Mixtures of smectite and Eltt~pulgite type~ in weight
ratios of 4 :1 to 1: 5 are also useful herein . Thickening or suspending
agents of the foregoing types are well known in the art, being described,
for example, in U.S. Patent No. 3,9135,668 referred to above. Abrasives or
polishing ag~nts should be avoided in the LADD compositions as they may
mar the surface of fine dishw~re, crystal and the like.
When used in combination with the fatty Acids or the fatty acid
polyvalent mztal salts, the clay thixotropic thickeners sre used in amounts
of 0.1 to 3%, preferably 0.1 to 2.5% and more preferably in amounts of 0.1
to2%.
When the cl~y thixotropic thickeners tlre used alone 118 the thixotroplc
thickener agent they can be u~ed in amounts of about 1.5 to 8%, preferably
2 to 5% by weight of the formulation.
Generally, LADD effectiveness i8 directly rel~ted to (8~ aYailable
chlorine levels; (b~ alkalinity; (~) solubility in washing medium; and (d~
30 I foam inhibition. It is pre~erred hereirl that the pE~ of the LADD composition
~ 1 3 ~
be at least about 9 . 5, more preferably from ~bout 10 . 5 to 13 . S and most
preferably at least about 11.5. At the relatively lower pH Yalue~, the
LADD product is too viscous, i.e. solid-li2ce, and thu~ not readily fluidized
under the shear-force level~ created within the dispenser cup under normsl
5 machine operating cond~tionE~. A~dition of NaOH is thus often needed to
increase the pH to within the above range~, ~nd to increase flowability
properties. The presenee of c~3rbonate i~ al80 often needed hereln, since it
8Ct8 as a bu~fer helping to maintain the degired pH level. Excess carbonate
is to be avoided, however, gince it may cauge the formation of needle-like
10 crystals of carbonate~ thereby impairing the gtabi~ty, thixotropy and/or
detergency of the LADD produc~, a~ well a6 impairing the dispensibility of
the product from, for example, gqueeze tube bottles. Caustic soda (NaOH)
serves the further function of neutr~izing the phogphorio or pho~phonic
acid e~ter foam depre~sant when present. About 0.5 to 3 wt% of NaOH and
15 about 2 to 9 wt% of sodium carbonate in the LADD composition are typical,
although it should be noted that sufMcient Alkalinity may be provided by
the NATPP and ~odium silicate.
The NaTPP may be employed in the LADD composition in a range of
about 8 to 35 wt%, preferably about 20 to 30 wt%, and should preerably be
20 free of heavy metal which tend~ to decompo~e or inaetivate the preferred
sodium hypochlorite and other chlorine bleach compounds. The NaTPP may
be anhydrou~ or hydrated, including ~he ~table hexahydrate with a degree
of hydration of 6 corresponding to about 18% by weight of water or more.
Actually, in ~riew of the stability of the hsxahydrate, the preRence of some
25 water of hydration i8 highly effective, serving it i8 thought to form 6eeds
of the stable hexahydrate which expedites hydration and solubilization of
the remaining NaTPP particles. If only the hexahydrate is used, the
detergent product may be too liquid. Conversely, if only the anhydrou~
NaTPP is used, the product may, in 60me case~, be t~o thick and,
30 there~ore, unsuitable. Especially preferred LADD compo3~tions are
: ~ 13~2~'~
obtained, for ex~mple, when using a 0.5:1 to 2:1 weight ratio of anhydrous
to hexahydrated NaTPP, values of about 1:1 being particularly preferred.
Foanl inhibition iB important to increa~e dishwa~her machine efficiency
. and minimize destabilizing ef~ects which might occur du~ to the presence of
excess foam within the wagher during use. Foam may be ~ufficiently
reduced by 3uit~ble 6election of the type and/or amount of detergent active
material, the main foam-producing component. The degree of foam i~ also
somewhat dependent on the hardnegs of the wagh water in the machine
whereby suitable adjustment of the propor~ionE~ of NaTPP which has a water
softening effect may aid in providing the de6ired degree of foam inhibition.
However, it is generally preferred to include a chlorine bleach stable ~oam
depressant or inhibitor. Particularly effective are the alkyl phosphonic acid
esters of the formula
~ .
HO--P--R
OR
available for example from BASF-Wyandotte (PCUK-PAE), and especially the
alkyl acid phosphate esters of the formula
e
HO--P--OR
OR
available, for example, from Hooker (SAP) and Knapsack ~LPXN-158), ~n
which one or both R groups in each type of e~ter may represent
independently a C12_20 alkyl groupO Mixtures of the two types, or any
other chlorine bleach ~table types, or mixtures of mono- and di-ester~ of
the same type, may be employed. Especially pre~erred is a mixture of
mono- and di-C16 18 alkyl acid phosphate ester~ ~uch as
monostearyl/distearyl acid pho~phates 1.2/1 ~Knapsack). When employed,
proportions of 0.01 to 5 wt%, pre~erably 0.1 to 5 wt%, especially about 0.1
~/ 30 to 0.5 Wt%7 of foam depressant in the compo~ition i8 typical, the weight
~3~2~ L~
ratio of detergen~ active component to foam depressant generally ranging
from about 10 :1 to 1:1 and preferably about ~ :1 to 1:1. Other defoamers
which may be used include, for example, the known silicones.
Although any chlorine bleach compound may be employed in the
compo~itions of this invention, such a8 dichloro-isocyanurate,
dichloro-dimethyl hydantoin, or chlorinated TSP, alkali metal, e. g.
potassium, lithium, magrlegium and egpeci~ly sodium hypochlolite is
preferred. The compo~;ition ghould contain ~3ufficient chlorine bleach
compound to provide about 0, 2 to 4 . 0% by weight of available chlorine, as
determined, for example, by acidification o 100 parts of the composition
with excess of hydrochloric acid . A solution containing about O . 2 to 4 . 096
by weight af sodium hypochlorite containg or provides roughly the xame
percentage of available chlorine. A solution containing about 0.8 to 1.6% by
weight sodium hypochlorite contains about 0.8 to 1.6% by weight of available
chlorine and i8 especislly preferred. For example, sodium hypochlorite
(NaOCI) solution of from about 11 to about 1396 available chlorine in amounts
of about 3 to 209~, preferably about 7 to 12~, can be ~dv~ntageously used.
The sodium silicate, which provides alkalinity and protection of hard
surfaces, such as fine china glaze and pattern, is employed in an smount
ranging from about 2.5 to 40 wt%, preferably about 10 to 35 wt96, in the
composition. The sodium ailicate also protects the w~shing machine from
corrosion. At the higher levels ~pecified herein for example at lev21s
greater than about 10 wt% the ~ilicate also provides increased antispotting
action. Th~ sodium silicate i8 generally added in the form of an aqueous
801ution, preferably having an Na20:SiO2 ratio s)f about 1:2.2 to 1:2.8, for
example, 1:2.4. Most of the other components of the composition9 especially
NaOH, sodium hypochlorite and foam depressant may 8180 be added in the
form of an aqueou~ dispersion or solution.
Detergent active materi~l us~ful herein must be stable in the presence
of chlorine bleach, especi~lly hypochlorite bleach, and those of the organic
~ ~
13i~
anionic, amine oxide, phosphine oxide, gulphoxide or betaine water
dispersible surfactant types are preferred, the first mentioned anionics
being most preferred. They are used in amount~ ranging from about 0.1 to
5% preferably about O . 3 to 2 . 0% . Particularly preferred surfactsnts herein
are the linear or branched alkali n etal mono- ~nd/or di-(C8 14~ alkyl
diphenyl oxide mono Qnd/or disulphonates, commerci~lly av~lable for
example as DOWFAX (Registered Trademark) 3B-2 and DOWFAX 2A-1.
In addition, the sul~fac~ant E~hould be compatible with the other
ingredient3 of the composition. Other ~uitable sur~actants ~nclude the
primary alkyl~ulphates, alkylsulphonates, alkylaryl-sulphonate~ and
sec -alkylsulphate~. Example~ include ~odium C10_18 alkylsulphates 8
~odium dodecylsulphate and sodium tallow alcohol~ulphste; sodium C10 18
alkanesulphonates such as sodium hexadecyl-l-sulphonate and ~odium C12 18
alkylbenzenesulphonates such as sodium dodecylbenzenesulphonstes. The
corresponding potassium salts may Pl80 be employed.
As other suitable surfact~nts or detergents, the amine oxide
surfaetants are typic011y of the structure R2RlNO, in which each R
represents a lower alkyl group, for instance, methyl, ~nd R1 repre6ents a
long chain alkyl group having from 8 to 22 carbon Qtoms, for instance
lauryl, myristyl, palmityl or cetyl group. Instead OI an amine oxide, ~
corresponding ~urfactsnt pho~phine oxide R2RlPO or ~ulphoxide RRlSO c~n
be employed. Betaine surfactants are typic~lly of the structure R2R1N -
R"COO, in which ea~h R represents a lower alkylene group having from 1
to 5 csrbon atoms. Specific examples of the~e wrfActants are
lauryl-dimethylamine o~Qde, myristyldimethyl~ninc oxide, the corresponding
phosphine o~cides and sulphoxideR, and the corre~ponding betaines,
including dodecyldimethylammonium acetate, tetradecyldiethylammonium
pentanoate, he2~adecyl-dimethylammonium hexanoate and the liXe. For
biodegradability, the alkyl group~ in these surfsct~nts should be linear,
and such compounds are preferred.
18
: ~ ~ 31~
Surfactants of the foregoing type, all well known in the art, are
escribed, for example, in U.S. Patents 3,985,668 and 4,271,93û.
The amount of water contained in these composition~ should, of course,
I e neither 80 high a~ to produce unduly low vi~cosity and fluidity, nor 80
5 ¦ ow as to produce unduly high vi6cosity and low flowability, thixotropic
¦ roperties in either case being diminished or degtroyed. æuch amount is
eadily detern~ihed by routine experimentation in any parti~ular in~tsnce,
generally ranging from about 25 ~o 75 wt%, preferably about 50 to 65 wt%.
he water should ~190 be preferably deionized or goMened. These amolmts
10 f water in the composition include the water added as part~ of the liquid
olution~ o~ other ingredients, but do no include ~ound water, for example
hat in NaTPP hexahydrate.
Other conventional ingredient~ may be included in these compositions
In smsll amounts, generally legg than about 3 wt%, such as perfume,
15 ydrotropic agents such a~ the sodium benzene, toluene, xylene and cumene
sulphonates, preservatives, dyestuffs and pigment~ and the like, all of
ourse being stE~ble to chlorine bleach compound and high alkalinity
(properties of ~11 the components). E~pecially preferred for coloring are
the chlorinated phthalocyanines and polysulphides of aluminosilieate ~Arhich
20 rovide, respectively, pleasing green and blue tints.
The liquid ADD compositionR of thi~ invention are readily employed in
nown manner for washing dishes, glas~es, cup8, eating utensils and the
like in an automatic dishwasher, provided with a ~uitable detergent
dispenser ~ in an aqueou~ wash bath contnining an effective amount of the
2 5 composition .
In a preferred embodiment of the invention the aqueous liquid
di6hwashing detergent compo~ition iB formulated using the below named
¦¦ngredientR.
1 3 1 ~ 2 ~ L~
Component Wei~ht Percent
Alkali Met~l Tripolyphosphate 10-25
Sodium Silicate l47.5%) 15-40
Silica Anti-filming Agent 1-4
Alalsli Metal Carbon~te (anhydrous~ 2-8
Chlorine Bleach Stable, Water Disper6ible Organic
Oetergent Active Material 0.~-3
Chlorine E~leach Stable Foam Depressant 0,10-3
Sodium Hypochlorite Bleach Compound 0,2-~
Fatty Acid Thixotropic Thickener0.03-0.5
Sodium Hydroxide ~50%) 2-6
Balance Water ~~
The thi~otropic aqueous liquid automatic dishwashing detergent
compositions of the present invention can contain conventional dishwashing
15 detergent composition additives. The formulations can be prepared with
commercially available solid powder builder~, and/or the ingredients can be
mixed and the formulation~ ground to a desired particle size.
The invention may be put into practice in various w~ys and a number
of specific embodiments will be described to illuYtrate the invention with
20 reference to the accompanying examples.
All amounts and proportions referred to herein are percerlt by weight
of the composition unless otherwi~e indicated.
The present invention is further illustrated by the following examples.
~9 13182~
ExamE!le 1
A thixotropic aqueous liquid ~lutomatic dishwashing detergent
composition i8 formulated from the following ingredien~s in the amount4
, specified .
Comporlent Weight Percent
Deionized Water 26.26
Knapsack LPKN-158 Foam Depressant(1) 0.16
Sodium Hydroxide (50%) 5.00
~odium Carbonate ~anhydrous)5.00
Sodium Tripolypho~phate (anhydrou~) 20.00
Silics Anti-filming Agent(2)2.00
Stearic Acid Thixotropic Thickener 0.10
Dowfax 3B-a Surfactant( ) 0.80
Sodium Hypochlorlte ( 11%) 9 .10
Sodium Si~cate (1/2.23 - 47%)31.58
100.00
(1) Mixture of mono and distearyl (C16-C18) ~llcyl esters of phosphoric
acid, mole ratio 1:1.3.
(2) Silica Syloid 244 ha~ a particle size of about 4 micron~ and is available
from W.R. Grace Co.
(3) Na mono- and didecyl diphenyl ether disulfonate (45% solution).
The ~te~ric acid i8 melted, and the ingredients are added to the water
generally in the order listed and gently stirred until a homogeneou~ mixture
i8 obtained. The formulation i~ tested by washing glassware and dishware
at a temperature of 130F in hard water (300 ppm hardne~s) in an automatic
di~hwa~hing machine and the clean and dried dishes are found to have no
apparent film.
21
: l ~ ~
1 ~3~2~
¦ Example 2
In order to demonstrate the effect of adding the silica anti-fflming
agent, formulations ~re prepared with and wiehout the ~ilica anti-filming
I agent and are compared to a commerci~ly aY~ilable powder detergent
5 ¦ composition.
The composition~ are formulated to contain the following Ingredients.
Silica(A) No Silica(~3)
l Component ~ Anti-film Agent
l Deionized Water 32.05 34.55
¦ Knapsack LPKN-158 Foam Depre~sant0.1~ 0.16
Sodium Hydroxide S50%) 5.00 5-
Sodium Carbonate ( anhydrou~) 5 . 00 5
Sodium Tripolyphosphate (anhydrou~) 20 . 00 20 . 00
I Silica (Syloid 244) Anti-filming Agent 2.50 ---
¦ Stearic Acid Thixotropic Thickener 0.10 0.10
Dowfax 3B-a Surfactant 0080 0.80
Sodium Hypochlorite (11%) 9.10 9.10
Sodium Sil~cate (1/2.23 - 47%) 25.29 25.29
l ' 100.00 100.00
¦ The stearic acid is melted, and the ingredients are added to the water
generally in the order listed and gently stirred until ~ homogeneous m~xture
i8 obtained. The ~ormulation i~ te~ted by washing glassware at 130F in
¦ hard water (300 ppm hardnes~).
l The two above formulations (A) and (B) were te~ted ~nd compared
2 5 ¦ with a commercîally avsil~ble powder automatic di3hw~6her detergent
¦ formulation (:. The formulation~ were te~ted in a Xenmore automatic
¦ dishwasher using the procedure de3cribed in A8TMD 3566-79, except that
¦ only four cleaning cycles are used. The filming and ~potting are e~raluated
according to the following ~cales:
22
~ 2 ~ ~
Film Rating Scale
1. Beqt, no apparent film
2. Filming ~light, becoming apparent
3. Noticeable film, increasing
5 4. Continued increase of aignificant film
5. Filming becoming excessive
6. ~ilming high, excessive buildup
7. Continued increase of excessive fflm.
Spot Rating Scale
10 A. Best - no 8pot8
Bo Very few spot~ apparent
C. Difitinct
D, Significant coverage approximately 50%.
The results obtained in the fourth cycle are reported in the below
15 Table 1.
TABLE 1
Formulation Performance Rating
Spot Film
(A) Silica Anti-filming Agent B-C 1-2
(B) No Silica Anti-filming Agent B-C 5-6
(C) Commercial Powder Detergent B-C 4-5
23
~ _
¦ Example 3
Thixotropic aqueous liquid ~utomatic dishwashing detergent
compositions are formulE~ted from the following ingredients in the amounts
~ ¦ ~pecified.
¦ ~ilica(D) No Silica(E)
I Component nti-fflm Agent Anti-film A~ent
I
¦ Deionized Water 32.638 34.638
Graphtol Green Pigment 0.002 0.002
~ Knap~ack LPKN-158 Foam Depre~sant 0.160 0.160
¦ Sodium Hydroxide ~ 5096~ 5 . 5 ~
Sodium Car`bonate ~anhydrous)5 . 000 5
Sodium Silicate (1/2,35 - 43.5%) 25.3S0 25.300
Sodium Tripolyphosphate (anhydrous) 20. 000 20. 000
I Silica Anti-filming Agent(l)2.000 ---
¦ Dowfax 3B-a Surfactant( ) 0.800 0.800
Stearic Acld(3) 0.100 0.10~
¦ Sodium Hypochlorite (11%) 9.000 _ 9.000
100.000 100.000
¦ (l) Silica (Huber Zeo 49) contains about 1% alumina (AL2O3) and h~s a20 I particle size of about 9 microns.
(2) Na mono and didecyl diphenyl ether disulfonate (45% solution~.
1~3~ Emersol 132 available from Emery Company.
l The stearic acid i8 melted, and the ingredients ~re added to the water
¦ generally in the order listed and ~tirred until a homogeneou~ mixture i8
25 ¦ obt~ined. The formulations are tested by wa hing gl&u~sware at 130F in
¦ hard water ~300 ppm hardne~s).
The two formulations were tested and compared ~o a commerci~l powder
¦ automatic dishwa~her detergent formulation F. The formul~tions were tested
¦ in a Kenmore automatic dishwasher using the procedure described in ASTMD
¦ 3566-79, except that only four cleaning cycles were used. The spotting
¦ and filming are evaluated as in Example 2 and the re~ults obtained in the
I fourth cycle are repor~ed in below Table 2.
~ j
TABLE 2
Performance Rating
~ Film
(D) Silica Anti-filming Agent B-C 1-2
(lE) No Silica Anti-filming Agent B-C 4
(F) Commercial Powder Detergent B-C 5-6
I
Exam~le ~
A thixotropic aqueous liquid Automatic dishwashing detergent
¦ compositioll is formulated from the following ingredients in the amounts
10 specified~
Component Weight Percent
Deioni~ed Water 38.7
Aluminum Stearate Thixotropic Thickener 0.25
Clay (Pharmagel H) Thixotropic Th~ckener 1.25
Sodium Silicate (1/2.4 - 47.5%) 17.73
Sodium Tripolyphosphate (anhydrous) 12 . 00
Sodium Tripolypho~phate (hexahydrate) 12 . 00
Silica Anti-filming Agent 2.00
Sodlium Csrbonate (anhydrous) 5.00
Sodium Hypochlorite (11%~ 7.61
Dowfa~ 313-2 Surfact~nt 0.80
Foam Depressant ) 0.16
Ss)dium Hydro~dde (50%) 2.~0
Graphitol Green 0.01
lOO.Oû
(I) 1:1 mixture of LPXN-158 and PCUK-PAE.
The ingredients are mixed :In 8 coslventional manner or ~re mixed
following the procedure of the copending commonly as3igned application
~ 3 ~
62301-1~08
Serlnl No. 546 121 fileti September 4th 1987.
The formuJatlon 19 te81cd by wMslllng gln6gw~re ~It 13~F Jn hord wnler.(~0~ ppm hnrdness) in nll nutomnllc dls~lwohhing mnchlne. Tlle clenn and
5drled glll6swnle are round to be rree Or rilm.
The thixotropic nqueous liquid outomnllc dl~hwo~lllng detergenl
composillon6 Or tlle pregen~ Inventlon provlde improved fllm properlieh.
The Invention 19 not to be llmlted by llle ~bove dl~3cloHure nnd Exnmple6
whlch are glven Oh iilu6trn~10ng only. The invenllon 1~ to be interpretecl In
10 accordance wilh the below clalm~.
ll 2
,~
.
