Note: Descriptions are shown in the official language in which they were submitted.
1089737
The invention relates to a detergency builder compo-
sition consisting predominantly of pyrophosphate and detergent
compositions containing it.
For many years the primary material used to control
water hardness in detergent products has been sodium tripoly-
phosphate at levels of approximately 50% by weight of the
finished detergent product. Within the past few years the
use of high levels of sodium tripolyphosphate has come under
scrutiny because of the suspicion that soluble phosphate species
accelerate the eutrophication or aging process of water bodies~
This eutrophication is ordinarily evidenced by the rapid growth
of algae in the water body. ,-
Sodium tripolyphosphate exists as a molecule contain-
ing 5 atoms of sodium, 3 of phosphorus, and 10 atoms of oxygen.
When utilized as a detergent builder the sodium tripolyphosphate
molecule sequesters as a soluble species one molecule of calcium
or magnesium cations per molecule of tripolyphosphate anion. In
other words, sodium tripolyphosphate sequesters calcium and mag-
` nesium ions on a 1:1 mole basis. The calcium or magnesium tri-
20 polyphosphate species is relatively stable in a wash solution, ;
thus preventing the water hardness from reacting with anionic
detergents which in turn gives better cleaning. The calcium or
magnesium tripolyphosphate species exists essentially as a
single trivalent negative anionic species in the wash solution.
This calcium or magnesium trivalent anion does not precipitate in
the course of the wasb.
.
,
-- 1 --
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1089'73'7
Sodium pyrophosphate has generally been considered
to be an equivalent builder when compared to sodium tripoly-
phosphate. It has also been suspected that sodium pyrophos-
phate is the equivalent of sodium tripolyphosphate in promoting
the eutrophicatlon as has been discussed above.
Sodium pyrophosphate contains one less atom of phos-
phorus than does sodium tripolyphosphate. The foregoing is
reflected in the empirical formula of sodium pyrophosphate which
is 4 atoms of sodium, 2 atoms of phosphorus and 7 atoms of
oxygen. Sodium pyrophosphate is also known to form a 1:1 molar
complex with calcium or magnesium ions. The species resulting
from the sequestration of calcium or magnesium by the tetrava-
lent negative pyrophosphate anion is the calcium or magnesium
divalent negatively charged pyrophosphate complex. This cal-
cium or magnesium pyrophosphate complex is sufficiently stable
in the wash solution to prevent the wat~r hardness cations from
interfering with the detergency process.
Aside from a molecular weight advantage which allows .
more moles of the pyrophosphate salt to be present in a compo-
sition at a given weight fraction of phosphate than tripoly-
phosphate, there would appear to be little difference between
using pyrophosphates and tripolyphosphate in detergent products.
However, such is not the case, one curious difference exists
between the pyrophosphate anion and the tripolyphosphate anion
and that is the ability of the former to precipitate as the
dicalcium pyrophosphate salt under normal wash conditions. The
precipitation of pyrophosphates has been sought to be avoided
in wash solutions as the salt formed has a tendency to build
up on fabrics and exposed machine surfaces. Furthermore the pre-
cipitation of calcium pyrophosphate is unpredictable under
.
10~9'73~
normal wash conditions where such factors as the total hard-
ness, the pH, and the ratio of calcium ions to magnesium ions
may vary from load to load.
Johnson states in U.S. Patent 2,381,960 issued
August 14, 1945 that water-hardness may be reduced by adding
pyrophosphates to the solution containing the hardness after
a supplemental alkaline material such as sodium orthophosphate,
alkali metal hydroxides and carbonates, soap and sodium silicate ~,
having an SiO2:Na20 ratio greater than 1.5 have been added to
the solution. Kepfer in U.S. Patent 2,326,950 issued August 17,
1943, discloses that pyrophosphate~ can be used to control water
hardness if the pyrophosphate is added to the solution contain-
ing the hardness prior to the addition of supplemetal alkaline
materials such as sodium borate, sodium metasilicate and sodium
dihydrogen phosphate. In both Johnson, supra, and Kepfer the
second component (Johnson-pyrophosphate and Kepfer-supplemental
alkaline material) is to be added to the solution prior to the
formation of a macroscopic precipitate.
It can thus be seen that pyrophosphate has the poten-
tial of being a much more effective detergency builder than have
the tripolyphosphate salts. The pyrophosphate tetravalent
anion has a high association constant with the first calcium
ion with which it associates. This first association product
is the monocalcium pyrophosphate divalent anion. The divalent
anion has a very small association constant with the second
calcium ion to form the dicalcium
89737
pyrophosphate salt which is electrically neutral. In the
absence of any material which makes the dicalcium pyrophos-
phate more stable one of the associated calcium ions will be
free to disassociate and to seek a more stable association
such as with body soil on the fabrics or with the anionic
detergent. The main purpose of controlling calcium ions
whether free or associated in a weak complex is to prevent
the last mentioned reaction with the detergent or soiled
fabric from occurring. As the pyrophosphate anion strongly
holds one mole of calcium ion per pyrophosphate anion it has
been common practice to attempt the first association
(sequestration) on a mole for mole basis. If, however, the
pyrophosphate anion can be induced to strongly associate
(precipitate) with two moles of calcium ion the pyrophosphate
level used could be reduced substantially. Preferably some
free pyrophosphate tetravalent anion will be present in the
wash for its value in peptizing clay soils.
It has been discovered, as disclosed in our U.S. Patent
4,019,998, issued April 26, 1977, that alkali metal pyrophos-
20 phates can be formulated into a detergent composition in a -~
manner such that the pyrophosphate builds by first associating
with and then precipitating up to two moles of calcium per
mole of pyrophosphate. However, it has long been the
experience of those skilled in the art that pyrophosphates
have not been very effective for whiteness maintenance. Good
"whiteness maintenance" results from the ability of a detergent
composition to prevent dirt dispersed in a wash liquor, for
instance having been washed out of soiled articles, from being
re-deposited upon clean or cleaned articles.
The invention provides builder compositions consisting
predominantly of pyrophosphate, and detergent compositions
containing them, which give improved whiteness maintenance.
-- 4 --
.
- lV89737
According to the invention there is provided a
detergent composition consisting essentially of: ~a) from
about 1% to about 50% by weight of the composition of an
organic surfactant selected from the group consisting of
water soluble anionic, nonionic, ampholytic and zwitter-
ionic surfactants and mixtures thereof; and (b) from about
5% to about 60% by weight of the composition of a detergent
builder consisting of a mixture of water soluble alkali
metal phosphates selected from the group consisting of
orthophosphates, pyrophosphates and tripolyphosphates,
wherein the amount of tripolyphosphate lies in the range
; from about 1~ to about 15~ by weight of the phosphate
mixture and wherein the amount of orthophosphates in the
phosphate mixture is less than about 1% by weight of the
phosphate mixture.
The pyrophosphate salts of the compositions of the
. present invention have alkali metal cations, such as sodium
or potassium, preferably sodium. Pyrophosphate salts useful
herein may be obtained commercially or may be formed by
neutralization of the corresponding phosphoric acid or the
acid salt.
As a general rule, the level of these phosphates in
the detergent compositions can be to as low as about half
the level of tripolyphosphate which would formerly have been
employed. The lowest levels can be obtained by use of the
methods disclosed below. Some compositions especially
intended for use in the prewash stage in the wash cycle of a
modern automatic washing machine have contained up to about
70% sodium tripolyphosphate. Other heavy duty detergents
contain only about 20%. Thus the preferred level of the
phosphate mixture of the invention is from about 12% to
about 45~ by weight of the composition.
- 5 -
.
'
108973'7
The proportion of tripolyphosphate (preferred) or ofhigher polyphosphates, is preferably from about 5 to about
12~ by weight of the total phosphates. Levels above about
15% serve no further purpose in improving whiteness maintenance,
and, in that tripolyphosphate is less efficient weight for weight
than pyrophosphate in aiding cleaning as indicated above, higher
levels are undesirable.
It is important that the content of orthophosphates
be very low. As little as 1% orthophosphate by weight of the
total phosphates is beginning to be harmful, and it is prefer-
red that less than 1/2% by weight be present.
Generally it is preferred that the detergent compo-
sitions be so formulated that they have pH in the range 9-12,
more preferably 9.8 to 11, in 1~ aqueous solution. This means
that usually the phosphates will be present in fully neutralized
form i.e. tetrasodium pyro- and penta-sodium tripolyphosphate,
but the acid forms may be employed if appropriate. Their state
of hydration is immaterial for the purposes of the invention. ;~
The other components of the invention can be any
which are used in detergent compositions.
Detergent Component
Preferably the detergent component when anionic, of
the present invention is a water-soluble salt of: an ethoxylated
sulfated alcohol with an average degree of etholxylation of
about 1 to 4 and an alkyl chain length of about 14 to 16:
tallow ethoxy sulfate; tallow alcohol sulfates; an alkyl benzene
sulfonate with an average alkyl chain length between 11 and 13,
preferably 11.2 carbon atoms; a C6-C20 ~-sulfocarboxylic acid
or ester thereof having 1 to 14 carbon atoms in the alcohol
30 radical; a C~-C24 paraffin sulfonate; a C10-C24 -olefin sulfo-
nate or mixtures thereof; or other anionic sulfur-containing
surfactant. Such preferred detergents are discussed below.
-- 6 --
108~73~7 -
An especially preferred alkyl ether sulfate
detergent component of the present invention is a mixture
of alkyl ether sulfates, said mixture having an average
(arithmetic mean) carbon chain length within the range of
about 12 to 16 carbon atoms, preferably from about 14 to
15 carbon atoms, and an average (arithmetic mean) degree Qf
ethoxylation of from about 1 to 4 moles of ethylene oxide,
preferably from about 2 to 3 moles of ethylene oxide.
Specifically, such preferred mixtures comprise
from about 0 to 10% by weight of mixture of C12 13 compounds,
from about 50 to 100% by weight of mixture of C14 15 compounds,
and from about 0 to 45% by weight of mixture of C16 17
compounds, and from about 0 to 10% by weight of a mixture
of C18 19 compounds. Further, such preferred alkyl ether
sulfate mixtures comprise from about 0 to 30% by weight of
mixture of compounds having a degree of ethoxylation of 0,
from about 45 to 95% by weight of mixture of compounds having
a degree of ethoxylation from 1 to 4, from about 5 to 25% by
weight of mixture of compounds having a degree of ethoxylation
from 5 to 8, and from about 0 to 15% by weight of mixtùre of
compounds having a degree of ethoxylation greater than 8.
~he sulfated condensation products of ethoxylated alcohols of
8 to 24 alkyl carbons and with from 1 to 30, preferably 1 to
4 moles of ethylene oxide may be used in place of the preferred
alkyl ether sulfates discussed above.
Another class of detergents which may be used in
the present invention includes the water-soluble salts, parti-
cularly the alkali metal, ammonium, and alkylolammonium salts
of organic sulfuric reaction products having in their molecular
structure an alkyl group containing from about 8 to about 22
1089737
carbon atoms and a sulfuric acid ester group. Examples of
this group of synthetic detergents are the sodium and potassium
alkyl sulfates, especially those obtained by sulfating the
higher alcohols (C8-C18 carbon atoms) produced by reducing
the glycerides of tallow or coconut oil.
Preferred water-soluble organic detergent compounds
herein include alkyl benzene sulfonates (preferably essentially
linear although "hard" ABS may be used) containing from about
9 to 15 carbon atoms in the alkyl group. Examples of the above
are sodium and potassium alkyl benzene sulfonates in which the
alkyl group contains from about ll to about 13 carbon atoms, in
straight chain or branched chain configuration, e.g., those of
the type described in U.S. Patents 2,220,099 and 2,477,383.
Especially valuable are straight chain alkyl benzene sulfonates
in which the average of the alkyl groups is about 11.2 carbon
atoms, abbreviated as Cll 2LAS.
Another useful detergent compound herein
includes the water-soluble salts of esters of -sulfonated
fatty acids containing from about 6 to 20 carbon atoms
in the fatty acid group and their esters from about 1 to 14
carbon atoms in the alcohol radical.
Preferred "olefin sulfonate" detergent mixtures
utilizable herein comprise olefin sulfonates containing
from about 10 to about 24 carbon atoms. Such materials
can be produced by sulfonation of ~-olefins by means of
uncomplexed sulfur trioxide followed by neutralization
under conditions such that any sultones present are
hydrolyzed to the corresponding hydroxy-alkane sulfonates.
-- 8 --
. . .
" . ,' : ' , ' ,, '~. ~
. .
1(~89737
The ~-olefin starting materials preferably have from 14
to 16 carbon atoms. Said preferred ~-olefin sulfonates
are described in u.S~ Patent 3,332,880.
The paraffin sulfonates embraced in the present
invention are essentially linear and contain from 8
to 24 carbon atoms, preferably 12 to 20 and more pre-
ferably 14 to 18 carbon atoms in the alkyl radical.
Other anionic detergent compounds herein in-
clude the sodium alkyl glyceryl ether sulfates,
especially those ethers of higher alcohols derived from
tallow and coconut oil; sodium coc-onut oil fatty acid
monoglyceride sulfonates and sulfates; and sodium or
potassium salts of alkyl phenol ethylene oxide ether
sulfate containing about 1 to about 10 units of ethylene
oxide per molecule and wherein the alkyl groups contain
about 8 to about 12 carbon atoms.
Water soluble salts of the higher fatty acids,
i.e. "soaps", are useful as the detergent component of
the composition herein. This class of detergents in-
cludes ordinary alkali metal soaps such as the sodium,potassium, ammonium and alkylolammonium salts of higher
fatty acids containing from about 8 to about Z4 carbon
atoms and preferably from about 10 to about 20 carbon
atoms. Soaps can be made by direct saponification of
fats and oils or by the neutralization of free fatty
acids. Particularly useful are the sodium and potassium
salts of the mixtures of fatty acids derived from
1~)8~737
coconut oil and tallow, i.e. sodium or potassium tallow
and coconut soap.
Water-soluble nonionic synthetic detergents are
also useful as the detergent component of the instant
composition. Such nonionic detergent materials can be
broadly defined as compounds produced by the condensa-
tion of alkylene oxide groups (hydrophilic in nature)
with an organic hydrophobic compound, which may be
aliphatic or alkyl aromatic in nature. The length of
the polyoxyalkylene group which is condensed with any
particular hydrophobic group can be readily adjusted
to yield a water-soluble compound having the desired
degree of balance between hydrophilic and hydrophobic
elements.
For example, a well-known class of nonionic
synthetic detergents is made available on the market
under the trade mark "Pluronic" sold by Wyandotte
Chemicals. These compounds are formed by condensing
ethylene oxide with a hydrophobic base formed by the
condensation of propylene oxide with propylene glycol.
Other suitable nonionic synthetic detergents include
the polyethylene oxide condensates of alkyl phenols,
e.g. the condensation products of alkyl phenols having
an alkyl group containing from about 6 to 12 carbon
atoms in either a straight chain or branched chain
configuration, with ethylene oxide, the said ethylene
oxide being present in amounts equal to 5 to 25 moles
of ethylene oxide per mole of alkyl phenol.
The water-soluble condensation products of
aliphatic alcohols having from 8 to 22 carbon atoms,
1~)89737
in either straight chain or branched configuration,
with ethylene oxide, e.g. a coconut alcohol-ethylene
oxide condensate having from 5 to 30 moles of ethylene
oxide per mole of coconut alcohol, the coconut alcohol
fraction having from 10 to 14 carbon atoms, are also
useful nonionic detergents herein.
Semi-polar nonionic detergents include water-
soluble amine oxides containing one alkyl moiety of
from about 10 to 28 carbon atoms and 2 moieties selected
from the group consisting of alkyl groups and hydroxy-
alkyl groups containing from 1 to about 3 carbon atoms;
water-soluble phosphine oxide detergents containing one
alkyl moiety of about 10 to 28 carbon atoms and 2
moieties selected from the group consisting of alkyl
groups and hydroxyalkyl groups containing from about
1 to 3 carbon atoms; and water-soluble sulfoxide deter-
gents containing one alkyl moiety of from about 10 to 28
carbon atoms and a moiety selected from the group con- ~.
sisting of alkyl and hydroxyalkyl moieties of from 1 to
3 carbon atoms.
Ampholytic detergents include derivatives of
aliphatic or aliphatic derivatives of heterocyclic
secondary and tertiary amines in which the aliphatic
moiety can be straight chain or branched and wherein
one of the aliphatic substituents contains from about 8
to 18 carbon atoms and at least one aliphatic substituent
contains an anionic water-solubilizing group.
Zwitterionic detergents include derivatives of
aliphatic quaternary ammonium, phosphonium and sulfonium
-- 11 --
1089737
compounds in which the aliphatic moieties can be straight
chain or branched, and wherein one of the aliphatic
substituents contains from about 8 to 18 carbon atoms
and one contains an anionic water-solubilizing group.
Other useful detergents include water-soluble
salts of 2-acyloxy-alkane-1-sulfonic acids containing
from about 2 to 9 carbon atoms in the acyl group and -
from about 9 to about 23 carbon atoms in the alkane
moiety; ~-alkyloxy alkane sulfonates containing from
about 1 to 3 carbon atoms in the alkyl group and from
about 8 to 20 carbon atoms in the alkane moiety; alkyl
dimethyl amine oxides wherein the alkyl group contains
from about 11 to 16 carbon atoms; alkyldimethyl-ammonio-
propane-sulfonates and alkyl-dimethyl-ammonio-hydroxy-
propane-sulfonates wherein the alkyl group in both
types contains from about 14 to 18 carbon atoms; soaps
as hereinabove defined; the condensation product of
tallow fatty alcohol with about 11 moles of ethylene
oxide; the condensation product of a C13 (avg.) secondary
alcohol with 9 moles of ethylene oxide; and alkyl glyceral
ether sulfates with from 10 to 18 carbon atoms in the
alkyl radical.
- A typical listing of the classes and species of
detergent compounds useful herein appear in U.S. Patent
3,852,211, to Ohren issued December 3, 1974. The foregoing
list of detergent compounds and mixtures which can be used
in the instant compositions is representative of such materials,
but is not intended to be limiting.
- 12 -
~089737
(i) from about 2~ to about 15% by weight of an alkyl sulfate
wherein the alkyl radical has from 10 to 20 carbon atoms
and mixtures thereof, the cation being an alkali metal
preferably sodium;
(ii) from about 2~ to about 15% by weight of an alkyl benzene
sulfonate having from 9 to 15 carbon atoms in the alkyl
radical and mixtures thereof, the cation being an alkali
metal preferably sodium. An additional component which
may be added to (i) and (ii) above is:
0 (iii) from about 2% to about 15% by weight of an alkyl ethoxy
sulfate having from 10 to 20 carbon atoms in the alkyl
radical and from 1 to 30 ethoxy groups and mixtures
thereof having an alkali metal preferably sodium cation.
The detergent is present in the detergent composi- ;
tion at levels of about 1~ to 50%, preferably from about 5%
to about 40%, and most preferably from about 10% to about 30
by weight.
Another very useful mixture of detergents comprises
nonionic and zwit*erionic agents, for instance sulphobetains
with a C8 18 aliphatic radical and surfactant polyethoxy
alcohols.
The detergent compositions may, and preferably do,
also contain an alkali metal silicate having the formula
SiO2:M20 wherein M is an alkali metal or mixtures thereof,
such as the sodium or potassium salt, preferably sodium.
The weight ratio SiO2:M20 is from about 1.6:1 to about 4:1,
preferably from about 2.4:1 to about 4:1, and most preferably
from about 2.75:1 to about 4:1.
The alkali metal silicate is present in the composi-
tion at from about 1% to about 25%, preferably about 2~ to about20% and most preferably about 4~ to about 15% by weight.
- 13 -
1~J8'~'737
Furthermore the compositions preferably contain
a diluent in an amount from about 0.1% to about 80%, prefer-
ably from about 1% to about 55%, and most preferably from
about 2~ to about 30% by weight.
- 13a -
- : :
lU89'~37
The diluent materials useful in the present inven-
tion are primarily but not necessarily inert in the composi-
tion. For instance a preferred diluent is sodium carbonate
which provides alkalinity to the composition thus favouring
detergency. The sodium carbonate will also neutralize the
acid pyrophosphates present in the slurry or admixed in dried
product thereby rendering the latter a more effective builder.
Additionally sodium carbonate will control water hardness to
a certain extent. On the other hand sodium sulfate also a
preferred diluent serves mainly to provide desirable granule
characteristics.
The diluents which are suitable in the present inven-
tion include natural and synthetic clays, alkali metal, especi-
ally sodium and potassium carhonates, bicarbonates, sesquicar-
bonates, borates, perborates, sulfates, chlorides, bisulfates,
and aluminates. Also useful as a diluent is calcium carbonate.
It i6 to be understood that the product by process
compositions of the present invention may be supplemented by
all manner of detergent components, either by includlng such
components in the aqueous slurry to be dried or by admixing
such components with the composition of the invention follow-
ing the drying step.
Other conventional components of detergent composi-
tions may be included in the compositions. These include per-
hydrate bleaching agents such as perborates and percarbonates,
and stabilisers, activators or catalysts therefore; enzymes
and stabilizers or protective agents therefore; soil suspending
agents; anti-caking agents; agents aiding the processing and
spray drying of nonionic detergents if these are used; germici-
des, optical brighteners, anti-caking agents; suds controlling
agents; colours and perfumes. Some of these components, as
- 14 -
~089737
is known in the art, are heat sensitive and are best added
to the dried product. :
- 14a -
1089737
Additional amounts of water-soluble detergency
builders may be added to the detergent compositions of the
present invention.
Examples of suitable organic detergency builder
salts are: (1) water-soluble aminopolycarboxylates, e.g.
sodium and potassium ethylenediaminetetraacetates,
nitrilotriacetates and N-(2-hydroxyethyl)-nitrilodi-
acetates;(2) water-soluble salts of phytic acid, e.g.
sodium and potassium phytatos -- see U.S. Patent 2,739,942;
(3) water-soluble polyphosphonates, including specifically,
sodium, potassium and lithium salts of ethane-l-hydroxy-l,l-
diphosphonic acid, sodium, potassium and lithium salts of
methylene diphosphonic acid, sodium, potassium and lithium
salts of ethylene diphosphonic acid, and sodium, potassium
and lithium salts of ethane-1,1,2-triphosphonic acid.
lOB9737
Other examples include the alkali metal salts of ethane-2-
carboxy-l,l-diphosphonic acid, hydroxymethanediphosphonic
acid, carbonyldiphosphonic acid, ethane-l-hydroxy-1,1,2-
triphosphonic acid, ethane-2-hydroxy-1,1,2-triphosphonic
acid, propane-1,1,3,3-tetraphosphonic acid, propane-1,1,2,3-
tetraphosphonic acid, and propane-1,2,2,3-tetraphosphonic
acid; and (4) water-soluble salts of polycarboxylate ~
polymers and copolymers as described in U.S. Patent ~:
3,308, 067.
A useful detergent builder which may be employed
in the present invention comprises a water-soluble salt
of a polymeric aliphatic polycarboxylic acid having the
following structural relationships as to the position
of the carboxylate groups and possessing the following
prescribed physical characteristics: (a) a minimum
molecular weight of about 350 calculated as to the acid
form; (b) an e~uivalent weight of about 50 to about 80
calculated as to acid form; (c) at least 45 mole percent .:
of the monomeric species having at least two carboxyl
radicals separated from each other by not more than
two carbon atoms; ~d) the site of attachment of the
polymer chain of any carboxyl-containing radical being
separated by not more than three carbon atoms along the
polymer chain from the site of attachment of the next
carboxyl-containing radical. Specific examples of
the above-described builders include polymers of itaconic
acid, aconitic acid, maleic acid, mesaconic acid, fumaric
acid, methylene malonic acid and citraconic acid and
copolymers with themselves.
- 16 -
1()8~'737
In addition, other builders which can be used
satisfactorily include water-soluble salts of mellitic
acid, citric acid, pyromellitic acid, benzene pentacarboxylic
acid, oxydiacetic acid, carboxymethyloxysuccinic acid, and
oxydisuccinic acid.
The detergent compositions of this invention pref-
erably contain the water-soluble detergent in a ratio to the
total builder present in a weight ratio of from about 10:1 to
about 1:10, preferably from about 3:1 to about 1:3. The amount
of additional builder in the detergent compositions of the
present invention is from about 5~ to about 50~, preferably
from about 10% to about 25~. These additional builders may
be dried with the aqueous slurry or admixed with the dried
product of the slurry. If desired the additional builder
can be the diluent material and thereby added to the slurry
to be dried.
Certain zeolites or alumino silicates when dried
with the components of the slurry enhance the function of
the silicate of the slurry and add building caapcity in that
the alumino silicates sequester calcium hardness. When ad-
mixed with the dried product of the slurry the alumino sili-
cates function as a cobuilder to the pyrophosphates. One such
alumino silicate which is useful in the compositions of the
invention is an amorphous water-insoluble hydrated compound
of the formula Nax(xAlO2 ySiO2), wherein x is an integer
of from 1 to 1.2 and y is 1, said amorphous material being
further characterized by a Mg++ exchange capacity of from about
50 mg eq. CaC03/g to about 150 mg eq. CaC03/g. This ion ex-
change builder is more fully decribed in Ireland published
30 application No. 1505j74 to B.H. Gedge et al, filed July 16,
1974.
11)89737
A second water-insoluble synthetic aluminosilicate
ion exchange material useful herein has the formula Naz[(Al02)z
(SiO2~y]xH20, wherein z and y are integers of at least 6; the
molar ratio of z to y is in the range from 1.0 to about 0.5,
and x is an integer from about 15 to about 264; said alumino-
silicate ion exchange material having a particle size diameter
from about 0.1 micron to about 100 microns, preferably to
about 15 microns; a calcium ion exchange capacity of at least about
200 mg eq./g; and a calcium ion exchange rate of at least about
10 2 grains/gallon/minute/gram. Such materials are further ,
described in Belgian patent 814,874. ~
The above described aluminosilicates are employed '
at levels of from about 1% to about 40%, preferably about 5%
to about 15% by weight.
'''~:; .
- 18 -
- .: : . .
1089737
The builder compositions of the invention may be
prepared in any suitable way, for instance by mixing phosphates
in suitable proportions.
The detergent compositions may be solids, liquids or
pastes, but are preferably granular solids. They may be manu-
factured by any effective method. However, so far as we know,
it is not possible to prepare them by methods which involve
heat drying, such as spray drying, the phosphates as this
would cause enough reversion of the pyro- and/or tripoly-
phosphate components to produce too much orthophosphate. Thus,it is preferred to mix the phosphates in particulate form, for
instance crystalline or ground, with the remainder of the
composition. Obviously, sufficiently pure grades, in
respect of orthophosphate content, must be used. For making
granular products it is preferred to make spray dried granules
comprising some or all of the non-heat-sensitive components of
the composition. These may be mixed with the phosphates, and,
for instance, the perhydrates if these are to be present. The
spray dried part of the compositions can be prepared by anym~ds
known in the art. However, to obtain the best possible
performance from a limited proportion of phosphatic builder,
the detergent compositions are preferably prepared by the
process of forming an aqueous slurry comprising the alkali
metal silicate and detergent, and the diluent. The slurry so
formed is then dried either in a single step or a series of
steps to a moisture content not exceeding about 5% by weight.
Preferably, the moisture content of the product immediately
following the drying operation will contain moisture at a level
of from about 0.1% to about 3%, most preferably from about
0.4~ to about 2% by weight.
-- 19 --
1, .
.,. .. . .: . . . . , : . .. . . . . . ..
.. . . . . . .
. ~ . . . . : . .
1089737
The statement that the moisture content should be
determined immediately following the last drying step is
necessary as the product may be allowed to rehydrate to
higher moisture levels without substantial performance loss.
Thus while the product may be dried to a moisture content of
2% by weight of the total solids present,that product may
be allowed to hydrate or take on water substantially in excess
of the limits expressed above. Apparently the manner in which ,
the moisture is distributed or held throughout the dried
product is more important than the total moisture content of
the product during its storage life.
Another explanation of the product performance may
be that the dried product when rehydrated does not revert to
its original composition.
The lower limit on the moisture content of the dried
product will be determined by the economics involved in that
the more the granule is dried the more costly the drying opera~
tion and that charring may result from the oxidation of the
organic components if the drying temperature is too high.
The slurry may be dried to a solid product of the
requisite moisture content by any convenient means. The drying
preferably is accomplished in a single step but may be done in
a series of steps. Such drying techniques include for example
by agglomeration such as is described in U.S. Patent 2,895,916.
Other methods of drying the compositions of the present inven-
tion include freeze drying, drum drying, and oven drying.
Preferably,however, the drying to a solid is carried out as
a single operation in spray-drying towers such as those described
- 20 -
.
9737
in U.S.Patents 3,629,951 and 3,629,955, both of which were
issued to Robert P. Davis et al, December 28, 1971.
Preferably the preparation of the detergent composi-
tion comprises the steps of adding the alkali metal silicate,
the detergent, and diluent as well as other compatible
ingredients, to an aqueous slurry and thoroughly mixing
(crutching) the composition. The thoroughly mixed slurry is
then dried such as by the previously mentioned spray-drying
operation. Where agglomeration or freeze drying is used it
may be necessary to further dry the product down to the re~uisite
moisture content by additional steps such as oven drying. The
product of the present invention is desirably in granular form.
Thus if the product is formed in large irregular chunks it is
ground to form the desired size granules. The products may be
formed into detergent bars as described in U.S. Patent 3,178,370
issued April 13, 1965 and sritish Patent 1,064,414 issued April
S, 1967 both to Okenfuss.
Granular products in the present invention are pref-
erably prepared by spray drying. The spray-drying operation
can be carried out in countercurrent or concurrent drying
towers, preferably in countercurrent towers. In its simplest
aspect the products of the present invention are spray dried
by pumping the slurry which has been~crutched to the spray-
drying tower where the slurry is fed through a series of
atomizing nozzles in a direction opposite to the flow of the
hot drying gases. The temperature of the hot air mixture should
be in the range of from about 150 to about 1500F,
- 21 -
: : :
1089~73~
.
preferably from about 200 to about 1000F, and most prefer-
ably from about 220 to about 700F.
The temperature range within which the granules of
the present invention reach is from about 120F to about 300F,
preferably from about 140F to about 275F, and most preferably
from about 150F to about 250F.
When a multilevel spray-drying apparatus is employed
such as described in the Davis et al patent, the product is ~-
suitably spray dried with the remaining conditions listed
therein.
The detergent composition prepared in accordance
with the present invention is preferably used in solid form
product, preferably a granule. However, the respective pro-
ducts can be ground to preferably a colloidal size and suspended
in an appropriate medium such as water and packaged as a liquid
composition.
It may be advantageous to mix the phosphates with
the dried granules in the presence of a binding agent, such
as a nonionic surfactant, gum or the like, so that they are `
caused to adhere to the surface of the dried granules.
- 22 -
1089~737
The following compositions were prepared:
Composition A B C D E
Sodium dodecylbenzene sulphonate 8.0 8.08.0 8.0 8.0
Nonionic surfactant 3,0 3.0 3.0 3.03.0
Fatty Acid 3.5 3.5 3.5 3.53.5
Sodium tripolyphosphate26.0 - 1.6 1.61.6
Sodium pyrophosphate 5.0 16 14.4 14.314.0
Sodium orthophosphate 1.0 0.06 0.05 0.140.4
Sodium silicate (solids7.0 7.0 7.0 7.07.0
10 SiO2:Na20 1.6:1)
Sodium perborate 25.0 25.0 25.0 25.025.0
Sodium sulphate 12.0 28.0 28.0 28.028.0
Minor components 3.5 3.5 3.5 3.53.5
~loisture 6.0 6.0 6.0 6.06.0
*These values are approximate, representing the products of
about 20% reversion during spray drying of the 32~ tripolyphos-
phate originally added.
Composition A was a spray dried granular composition,
with sodium perborate dry mixed.
Composition C is an accord with the invention; the
other compositions are comparative.
Compositions B to E were made by dry mixing the
phosphates, as purchased (B and C) and with added orthophos-
phate (D and E), with granular products representing the
remaining components.
All the products had substantially equal cleaning
properties. Their whiteness maintenance performance was
measured as follows:
108~73~
meter in 18H(258ppm as CaCo3) water containing an artificial
soil consisting of
Air Filter Soil 200 ppm
Clay 200 ppm
Lipid 100 ppm
using the above compositions at the concentrations stated
below. The test solutions and swatches were charged into
the launderometer pots at 20C, and heated during the wash
cycle of the machine to 95C during 75 minutes. The swatches
were removed, rinsed in 18H water and dried; for a single
cycle test their reflectance was measured, for a double cycle
test they were washed again in fresh soil-containing wash
liquor, rinsed and dried and their reflectance measured. The
whiteness maintenance values were the reflectance of the
washed swatches recorded as a percentage of the initial reflec-
tance of the swatches before treatment.
Test 1 Two cycles
Values for final reflectance as a percentage of
initial reflectance were~
20 Composition Concentration (% by weight in wash liquor)
0.4 0.6 0.8
A 95 95 93
B 83 80 86
C 93 90 88
Test 2 Single cycle
Composition Concentration (~ by weight in wash liquor)
.
0.4 0.6 0.8
A 97 97 96
B 89 90 88
C 92 93 ~94
D 89 87 87
E 86 84 85
- 24 -
~0~737
The random error of the values is a~out - 1 units
per cent.
- 24a -
~, .' ~' ' , ' ' , ~ ' ' , '
