[0001] The present invention concerns the improved stability of certain bleaching agents
in detergent compositions. In particular it relates to the improved stability of percarbonate
bleach particles.
[0002] Percarbonate bleach is currently being proposed as an alternative to perborate bleach
which has commonly been used in detergent compositions in the past. Sodium percarbonate
is an attractive perhydrate for use in detergent compositions because it dissolves
readily in water, is weight efficient and, after giving up its available oxygen, provides
a useful source of carbonate ions for detergency purposes. However, one problem is
that percarbonate is less stable in granular detergents than perborate. In particular
this stability problem is more apparent when water-insoluble silicates such as aluminosilicates
and/or clays are present in the composition.
[0003] Aluminosilicates and clays are common components of granular detergents. Certain
aluminosilicates are employed most commonly for their ability to complex with metal
ions such as calcium and magnesium which are present in hard water, and certain clays
are used for their ability to impart softness to fabrics. However the presence of
heavy metal ions in these components is unavoidable.
[0004] Particulate detergent components comprising clays have been proposed in the prior
art.
[0005] GB 2 121 843, published on 8th April 1982 describes the use of silicate as a binder
for clay particles. EP-A 340 004, published on 2nd November, 1989, describes the use
of anionic surfactant as the binder for clay particles and also suggests that silicate
may be used in addition. The use of such particles in bleaching compositions comprising
perborate is disclosed.
[0006] However, neither mentions the stability problems associated with percarbonate bleach,
or suggests ways in which this problem may be solved.
[0007] WO92/6163, published on 16th April, 1992, suggests that the percarbonate stability
problem arises predominantly from the presence of heavy metal ions which catalyse
the decomposition of the percarbonate, and proposes to limit such ions as well as
to control moisture to inhibit the catalysed degradation of the bleaching agent. The
application also mentions the possibility of coating percarbonate with protective
layer (including silicate), and adding chelants to the compositions to immobilise
the heavy metal ions. However further improvements are still sought which would allow
improvemements in percarbonate stability in formulations containing aluminosilicates
and/or clays, in order to give more flexibility to formulate compositions which comprise
certain bleaching agents.
[0008] It has now been found that the presence of water-soluble silicate in the clay particle
greatly improves percarbonate stability. This development offers a number of advantages,
including the possibility to formulate compositions with increased levels of clay,
and to make products having a higher level of moisture than was previously possible.
Summary of the Invention
[0009] The present invention relates improvements in the stability of granular detergent
compositions comprising certain bleaching agents. The compositions of the invention
comprise:
i) a granular component comprising a clay and water-soluble silicate; and
ii) a granular component comprising a bleaching agent chosen from the group comprising
alkalimetal percarbonate, peroxyacid, perimidic acid or combinations of these.
Detailed Description of the Invention
[0010] The present invention relates to a granular detergent composition comprising
i) a granular component comprising a clay and water-soluble silicate; and
ii) a granular component comprising a bleaching agent chosen from the group comprising
alkalimetal percarbonate, peroxyacid, perimidic acid or combinations of these.
[0011] The invention particularly relates to clays of natural origin, because these minerals
frequently comprise heavy metal ions such as iron, copper and manganese.
[0012] In a preferred embodiment, the present invention comprises clays of the smectite
type, for example, a trioctahedral mineral of the hectorite type, or a dioctahedral
mineral of the montmorillonite type.
Furthermore the clay may be modified by the addition of cationic or amino organic
compounds.
Preferably, in this embodiment of the invention, the granular detergent composition
will comprise clay at a level of at least 5% by weight of the granular detergent composition.
[0013] The water-soluble silicate preferably has a ratio of SiO
2 to Na
2O of between 2.0:1 and 3.3:1.
[0014] In another embodiment of the invention, the water-soluble silicate may be partly
added to the granular component comprising the clay, and partly dry mixed with the
remainder of the composition. The dry mixed portion of the water-soluble silicate
in this embodiment should comprise less than 10% by weight of the granular detergent
composition.
[0015] In another embodiment of the invention alkalimetal percarbonate has a granular form,
the outer surface of the granules being substantially coated in order to further improve
the stability of the bleach. Preferably the coating of the alkalimetal percarbonate
particles comprises less than 2% by weight of silicate.
[0016] In a most preferred embodiment of the invention, the granular detergent composition
comprises at least 12% by weight of zeolite and less than 1% by weight of any of the
chelating agents chosen from the group of aminocarboxylates, aminophosphonates, polyfunctionally-substituted
aromatic chelating agents, or mixtures of these.
[0017] The various components mentioned above will now be described in more detail.
[0018] The granular compositions of tne present invention comprise, firstly, a component
comprising water-insoluble clays which may be either unmodified or organically modified.
Those clays which are not organically modified can be described as expandable, three-layered
clays, i.e., aluminosilicates and magnesium silicates, having an ion exchange capacity
of at least 50 meq/100g. of clay and preferably at least 60 meq/100 g. of clay. The
starting clays for the organically modified clays can be similarly described. The
term "expandable" as used to describe clays relates to the ability of the layered
clay structure to be swollen, or expanded, on contact with water. The three-layer
expandable clays used herein are those materials classified geologically as smectites.
There are to distinct classes of smectite-type clays that can be broadly differentiated
on the basis of the numbers of octahedral metal-oxygen arrangements in the central
layer for a given number of silicon-oxygen atoms in outer layers. A more complete
description of clay minerals is given in "Clay Colloid chemistry" by H. van Olphen,
John Wiley & Sons (Interscience Publishers), New York, 1963. Chapter 6, especially
pages 66-69.
[0019] The family of smectite (or montmorillonoid) clays includes the following trioctahedral
minerals: talc; hectorite; saponite; sauconite; vermiculite; and the following dioctahedral
minerals: prophyllite; montmorillonite; volchonskoite and nontronite.
[0020] The clays employed in these compositions contain cationic counterions such as protons,
sodium ions, potassium ions, calcium ions, and lithium ions. It is customary to distinguish
between clays on the basis of one cation predominantly or exclusively absorbed. For
example, a sodium clay is one in which the absorbed cation is predominantly sodium.
Such absorbed cations can become involved in exchange reactions with cations present
in aqueous solutions. A typical exchange reaction involving a smectite-type clay is
expressed by the following equation :
[0021] Since in the foregoing equilibrium reaction, an equivalent weight of ammonium ion
replaces an equivalent weight of sodium, it is customary to measure cation exchange
capacity (sometimes termed "base exchange capacity") in terms of milliequivalents
per 100 g. of clay (meq/100g). The cation exchange capacity of clays can be measured
in several ways, including by electrodialysis, by exchange with ammonium ion followed
by titration, or by a methylene blue procedure, all as fully set forth in Grimshaw,
"The Chemistry and Physics of Clays", pp. 264-265, Interscience (1971). The cation
exchange capacity of a clay material relates to such factors as the expandable properties
of the clay, the charge of the clay (which in turn is determined at least in part
by the lattice structure), and the like. The ion exchange capacity of clays varies
widely in the range form 2 meq/100 g. of kaolinites to 150 meq/100 g., and greater,
for certain smectite clays.
[0022] In a preferred embodiment of the invention a smectite-type clay is present in the
clay/aluminosilicate component. sodium, potassium, lithium, magnesium, calcium clays
may be used.
[0023] Preferred smectite-type clays are sodium montmorillonite, potassium montmorillonite,
sodium hectorite and potassium hectorite. The clays used herein have a particle size
range of up to 1 micrometer.
[0024] Any of the clays used herein may be either natrally or synthetically derived. However
the present invention has been found to be particularly useful when natural clays
are used owing to the generally higher levels of heavy metal ions which are present
in natural minerals.
[0025] In addition to the clays described above, another family of water-insoluble silicates
which may be used in the present invention are described below.
[0026] One example is crystalline aluminosilicate ion exchange material of the formula :
Na
z[(AlO
2)
z·(SiO
2)
y]·xH
2O
wherein z and y are at least about 6, the molar ratio of z to y is from 1.0 to 0.4
and z is from 10 to 264. Amorphous hydrated aluminosilicate materials useful herein
have the empirical formula :
M
z(zAlO
2·ySiO
2)
wherein M is sodium, potassium, ammonium or substituted ammonium, z is from 0.5 to
2 and y is 1, said material having a magnesium ion exchange capacity of at least 50
milligram equivalents of CaCO
3 hardness per gram of anhydrous aluminosilicate. Hydrated sodium Zeolite A with a
particle size of from 1 to 10 micrometers is preferred.
[0027] The aluminosilicate ion exchange builder materials herein are in hydrated form and
contain from 1.5% to 35% by weight, preferably from 5% to 22% by weight, and more
preferably 10% to 15% by weight of water by weight if crystalline, and potentially
even higher amounts of water if amorphous. The crystalline aluminosilicate ion exchange
materials are further characterized by a particle size diameter of from 0.1 micrometers
to 10 micrometers. Amorphous materials are often smaller, e.g., down to less than
0.01 micrometers. Preferred ion exchange materials have a particle size diameter of
from 0.2 micrometers to 4 micrometers. The term "particle size diameter" herein represents
the average particle size diameter by weight of a given ion exchange material as determined
by conventional analytical techniques such as, for example, microscopic determination
utilizing a scanning electron microscope. The crystalline aluminosilicate ion exchange
materials herein are usually further characterized by their calcium ion exchange capacity,
which is at least 200 mg equivalent of CaCO
3 water hardness/g of aluminosilicate, calculated on an anhydrous basis, and which
generally is in the range of from 300 mg eq./g to 352 mg eq./g. The aluminosilicate
ion exchange materials herein are still further characterized by their calcium ion
exchange rate which is at least 9.05 mg/litre/minute/gram/litre (2 grains Ca
++/gallon/minute/gram/gallon) of aluminosilicate (anhydrous basis), and generally lies
within the range of from about 9.05 mg/litre/minute/gram/litre (2 grains/gallon/minute/gram/gallon)
to 27.15 mg/litre/min/gram/litre (6 grains/gallon/minute/gram/gallon), based on calcium
ion hardness. Optimum aluminosilicate for builder purposes exhibit a calcium ion exchange
rate of at least 18,1 mg/litre/min/gram/litre (4 grains/gallon/minute/gram/gallon).
[0028] The amorphous aluminosilicate ion exchange materials usually have a Mg
++ exchange of at least 50 mg eq. CaCO
3/g (12 mg Mg
++/g) and a Mg
++ exchange rate of at least (4 mg/litre/minute/gram/litre. 1 grain/gallon/minute/gram/gallon).
Amorphous materials do not exhibit an observable diffraction pattern when examined
by Cu radiation (1.54 Angstrom Units).
[0029] Aluminosilicate ion exchange materials useful in the practice of this invention are
commercially available. The aluminosilicates useful in this invention can be crystalline
or amorphous in structure and can be naturally occurring aluminosilicates or synthetically
derived. A method for producing aluminosilicate ion exchange materials is discussed
in U.S. Pat. No. 3,985,669, Krummel et al., issued Oct. 12, 1976. Preferred synthetic
crystalline aluminosilicate ion exchange materials useful herein are available under
the designations Zeolite A, Zeolite B, Zeolite M, Zeolite P and Zeolite X. In an especially
preferred embodiment, the crystalline aluminosilicate ion exchange material has the
formula :
Na
12[(AlO
2)
12(SiO2)
12]·xH
2O
wherein x is from 20 to 30, especially 27 and has a particle size generally less than
5 micrometers.
[0030] An essential feature of the present invention is the presence of water-soluble silicate
in the same particle as the clay/aluminosilicate.
[0031] Water-soluble silicates which are suitable for use in the present invention may be
amorphous or crystalline layered.
[0032] Such silicates may be characterised by the ratio of SiO
2 to Na
2O in their structure. In the present invention, this ratio may typically lie in the
range of from 3.3:1 to 2.0:1, preferably 3.3:1 to 2.4:1, more preferably 3.3:1 to
2.8:1, most preferably 3.3:1 to 3.0:1.
[0033] Crystalline layered sodium silicates have the general formula :
NaMSi
xO
2x+1 · yH
2O
wherein m is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from
0 to 20. Crystalline layered sodium silicates of this type are disclosed in EP-A 164
514 and methods for their prearation are disclosed in DE-A 34 17 649 and DE-A 37 42
043. For the purposs of the present invention, x in the general formula above has
a value of 2, 3 or 4 and is preferably 2. More preferably M is sodium and y is ) and
preferred examples of this formula comprise the α-, β-, γ-, δ- forms of Na
2Si
2O
5. These materials are available from Hoechst AG, Germany, as, respectively, NaSKS-5,
NaSkS-7, NaSKS-11 and NaSKS-6. The most preferred material is δ- Na
2Si
2O
5, NaSKS-6.
[0034] The laundry detergent compositions of the present invention preferably comprise amorphous
silicate or crystalline layered silicate at a level of from 1% to 40% by weight of
the composition, more preferably from 1% to 20% by weight.
[0035] The water-soluble silicate which is present in the finished composition may be partly
added to the clay/aluminosilicate component, and partly added to the rest of the composition
by some other means. Such means includes the dry mixing of silicate particles. Suitable
silicate particles may be prepared by spray drying although alternative processing
routes will be evident to the man skilled in the art. Furthermore the man skilled
in the art of detergent formulation will choose different types of silicate for use
in the various components of the composition. For example a layered silicate and/or
a low ratio silicate may be dry added, whereas a higher ratio silicate may be chosen
for use in the clay/aluminosilicate component of the same composition.
[0036] It is preferred that the silicate component of the present invention comprises less
than 25% by weight of water-soluble silicate and preferably from 3% to 15% by weight.
When dry added water-soluble silicate is used, it is preferred that less than 10%
by weight of the finished composition is dry added water-soluble silicate.
[0037] The granular compositions of the present invention further comprise a granular component
comprising a bleaching agent chosen from the group comprising alkalimetal percarbonate,
peroxyacid, perimidic acid or combinations of these. (This component is described
hereinafter as the "bleaching component")
[0038] Percarbonate will generally be solid and granular in nature. It may be added to granular
detergent compositions without additional protection. However, such granular compositions
may utilise a coated form of the material which provides better storage stability
for the percarbonate in the granular product.
[0039] The sodium salt of percarbonate is preferred for use in the present invention. Sodium
percarbonate is an addition compound having a formula corresponding to 2Na2CO3.3H2O2,
and is available commercially as a crystalline solid. Most commercially available
material includes a low level of a heavy metal sequestrant such as EDTA, 1-hydroxyethylidene
1,1-diphosphonic acid (HEDP) or an amino-phosphonate, that is incorporated during
the manufacturing process. For the purposes of the present invention, the percarbonate
may be incorporated into detergent compositions without additional protection, but
preferred embodiments of the invention utilise a coated form of the material. Suitable
coating materials include the alkali and alkaline earth metal carbonates and sulphates
or chlorides. The most preferred coating material comprises a mixed salt of alkali
metal sulphate and carbonate. Such coatings together with coating processes have previously
been described in GB 1 466 799, granted to Interox on 9th March, 1977. The weight
ratio of the mixed salt coating material to percarbonate lies in the range from 1:200
to 1:4, more preferably from 1:100 to 1:10, and most preferably from 1:50 to 1:20.
Preferably, the mixed salt is of sodium sulphate and sodium carbonate which has the
general formula Na2SO4.n.Na2CO3 wherein n is from 0.1 to 3, preferably n is from 0.3
to 1.0 and most preferably n is from 0.2 to 0.5.
[0040] Another suitable coating material is sodium silicate of SiO2:Na2O ratio from 1.6:1
to 3.4:1, preferably 2.8:1, applied as an aqueous solution to give a level of less
than 2% of silicate solids by weight of percarbonate. Magnesium silicate can also
be included in the coating.
[0041] Where the bleaching processes utilising the compositions of the invention are carried
out at least in part at temperatures lower than 60°C, the compositions of the invention
may contain bleaching agents more suited to low temperature bleaching. These will
include, for example, preformed organic peracids and perimidic acids.
[0042] The following are examples of preformed peroxy acids or perimidic acids which are
useful in the present invention:
- PAP:
- N,N phthaloylaminoperoxy caproic acid
- C-PAP:
- 2-carboxy-phthaloylaminoperoxy caproic acid
- PAPV:
- N,N phthaloylaminoperoxy valeric acid
- NAPAA:
- Nonyl amide of peroxy adipic acid
- DPDA:
- 1, 12 diperoxydodecanedioic acid
Peroxybenzoic acid and ring substituted peroxybenzoic acid
Monoperoxyphtalic acid (magnesium salt, hexahydrate) Diperoxybrassylic acid
Optional Ingredients:
[0043] In addition to the components described above, the compositions of the present invention
may also include other optional ingredients which may be useful in detergent compositions.
Such optional ingredients will now be described in more detail below.
Surfactants
[0044] Surfactants are selected from the group consisting of anionic, zwitterionic, ampholytic
and cationic surfactants, and mixtures thereof. Anionic surfactants are preferred.
Surfactants useful herein are listed in U.S. Pat. No. 3,664,961, Norris, issued May
23, 1972, and in U.S. Pat. No. 3,919,678, Laughlin et al., issued Dec. 30, 1975. Useful
cationic surfactants also include those described in U.S. Pat. No. 4,222,905, Cockrell,
issued Sept. 16, 1980, and in U.S. Pat. 4,239,659, Murphy, issued Dec. 16, 1980. However,
cationic surfactants are generally less compatible with the aluminosilicate materials
herein, and thus are preferably used at low levels, if at all, in the present compositions.
The following are representative examples of surfactants useful in the present compositions.
[0045] Water-soluble salts of the higher fatty acids, i.e., "soaps", are useful anionic
surfactants in the compositions herein. This includes alkali metal soaps such as the
sodium, potassium, ammonium, and alkylammonium salts of higher fatty acids containing
from 8 to 24 carbon atoms, and preferably from 12 to 18 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 coconut oil and tallow, i.e., sodium or potassium tallow and coconut
soap.
[0046] Useful anionic surfactants also include the water-soluble salts, preferably the alkali
metal, ammonium and alkylolammonium salts, of organic sulfuric reaction products having
in their molecular structure an alkyl group containing from 10 to 20 carbon atoms
and a sulfonic acid or sulfuric acid ester group. (Included in the term "alkyl" is
the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants
are the sodium and potassium alkyl sulfates, especially those obtained by sulfating
the higher alcohols (C
8-C
18 carbon atoms) such as those produced by reducing the glycerides of tallow or coconut
oil; and the sodium and potassium alkyl benzene sulfonates in which the alkyl group
contains from 9 to 15 carbon atoms, in straight or branched chain configuration, e.g.,
those of the type described in U.S. Pat. Nos. 2,220,099 and 2,477,383.
[0047] Other anionic surfactants herein are the sodium alkyl glyceryl ether sulfonates,
especially those ethers of higher alcohols derived from tallow and coconut oil; sodium
coconut oil fatty acid monoglyceride sulfonates and sulfates; sodium or potassium
salts of alkyl phenol ethylene oxide ether sulfates containing from 1 to 10 units
of ethylene oxide per molecule and wherein the alkyl groups contain from 8 to 12 carbon
atoms; and sodium or potassium salts of alkyl ethylene oxide ether sulfates containing
from 1 to 10 units of ethylene oxide per molecule and wherein the alkyl group contains
from 10 to 20 carbon atoms.
[0048] Other useful anionic surfactants herein include the water-soluble salts of esters
of alpha-sulfonated fatty acids containing from 6 to 20 carbon atoms in the fatty
acid group and from 1 to 10 carbon atoms in the ester group; water-soluble salts of
2-acyloxy-alkane-1-sulfonic acids containing from 2 to 9 carbon atoms in the acyl
group and from 9 to 23 carbon atoms in the alkane moiety; alkyl ether sulfates containing
from 10 to 20 carbon atoms in the alkyl group and from 1 to 30 moles of ethylene oxide;
watersoluble salts of olefin sulfonates containing from 12 to 24 carbon atoms; and
beta-alkyloxy alkane sulfonates containing from 1 to 3 carbon atoms in the alkyl group
and from 8 to 20 carbon atoms in the alkane moiety.
[0049] Also useful are the sulphonation products of fatty acid methyl esters containing
a alkyl group with from 10 to 20 carbon atoms. Preferred are the C16-18 methyl ester
sulphonates (MES)
[0050] Water-soluble nonionic surfactants are also useful as secondary surfactant in the
compositions of the invention. Such nonionic materials include compounds produced
by the condensation 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.
[0051] Suitable nonionic surfactants 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 16 carbon atoms, in either a straight chain or branched chain configuration,
with from 4 to 25 moles of ethylene oxide per mole of alkyl phenol.
[0052] Preferred nonionics are the water-soluble condensation products of aliphatic alcohols
containing from 8 to 22 carbon atoms, in either straight chain or branched configuration,
with from 4 to 25 moles of ethylene oxide per more of alcohol. Particularly preferred
are the condensation products of alcohols having an alkyl group containing from 9
to 15 carbon atoms with from about 4 to 25 moles of ethylene oxide per mole of alcohol;
and condensation products of propylene glycol with ethylene oxide.
[0053] Other useful nonionic surfactants are based upon natural renewable sources such as
glucose. Alkyl polyglucoside (APG), preferably those containing from 10 to 20 carbon
atoms and an average of from 1 to 4 glucose groups. Also useful are nonionic surfactants
based on polyhydroxy fatty acid amides which contain an alkyl group with from 10 to
20 carbon atoms, for example tallow N-methyl glucamine.
[0054] Semi-polar nonionic surfactants include water-soluble amine oxides containing one
alkyl moiety of from 10 to 18 carbon atoms and 2 moieties selected from the group
consisting of alkyl groups and hydroxyalkyl groups containing from 1 to 3 carbon atoms;
water-soluble phosphine oxides containing one alkyl moiety of 10 to 18 carbon atoms
and 2 moieties selected from the group consisting of alkyl groups and hydroxyalkyl
groups containing from 1 to 3 carbon atoms; and water-soluble sulfoxides containing
one alkyl moiety of from 10 to 18 carbon atoms and a moiety selected from the group
consisting of alkyl and hydroxyalkyl moieties of from about 1 to 3 carbon atoms.
[0055] Ampholytic surfactants include derivatives of aliphatic or aliphatic derivatives
of heterocyclic secondary and tertiary amines in which the aliphatic moiety can be
either straight or branched chain 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.
[0056] Zwitterionic surfactants include derivatives of aliphatic quaternary ammonium phosphonium,
and sulfonium compounds in which one of the aliphatic substituents contains from 8
to 18 carbon atoms.
[0057] Particularly preferred surfactants herein include tallow alkyl sulfates; coconutalkyl
glyceryl ether sulfonates; alkyl ether sulfates wherein the alkyl moiety contains
from 14 to 18 carbon atoms and wherein the average degree of ethoxylation is from
1 to 4; olefin or paraffin sulfonates containing from 14 to 16 carbon atoms; alkyldimethylamine
oxides wherein the alkyl group contains from 11 to 16 carbon atoms; alkyldimethylammonio
propane sulfonates and alkyldimethylammonio hydroxy propane sulfonates wherein the
alkyl group contains from 14 to 18 carbon atoms; soaps of higher fatty acids containing
from 12 to 18 carbon atoms; condensation products of C9-C15 alcohols with from 3 to
8 moles of ethylene oxide, and mixtures thereof.
[0058] Useful cationic surfactants include water-soluble quaternary ammonium compounds of
the form R
4R
5R
6R
7N
+X
-, wherein R
4 is alkyl having from 10 to 20, preferably from 12-18 carbon atoms, and R
5, R
6 and R
7 are each C
1 to C
7 alkyl preferably methyl; X
- is an anion, e.g. chloride. Examples of such trimethyl ammonium compounds include
C
12- 14 alkyl trimethyl ammonium chloride and cocalkyl trimethyl ammonium methosulfate.
[0059] Specific preferred surfactants for use herein include: alpha-olefin sulphonates;
triethanolammonium C
11-C
13 alkylbenzene sulfonate; alkyl sulfates, (tallow, coconut, palm, synthetic origins,
e.g. C
45, etc.); sodium alkyl sulfates; methyl ester sulphonate; sodium coconut alkyl glyceryl
ether sulfonate; the sodium salt of a sulfated condensation product of a tallow alcohol
with about 4 moles of ethylene oxide; the condensation product of a coconut fatty
alcohol with about 6 moles of ethylene oxide; the condensation product of tallow fatty
alcohol with about 11 moles of ethylene oxide; the condensation of a fatty alcohol
containing from 14 to 15 carbon atoms with about 7 moles of ethylene oxide; the condensation
product of a C
12-C
13 fatty alcohol with about 3 moles of ethylene oxide; 3-(N,N-dimethyl-N-coconutalkylammonio)-2-hydroxypropane-1-sulfonate;
3-(N,N-dimethyl-N-coconutalkylammonio)-propane-1-sulfonate; 6- (N-dodecylbenzyl-N,N-dimethylammonio)
hexanoate; dodecyldimethylamine oxide; coconutalkyldimethylamine oxide; and the water-soluble
sodium and potassium salts of coconut and tallow fatty acids.
Detergency Builders
[0060] Any compatible detergency builder or combination of builders or powder can be used
in the process and compositions of the present invention.
[0061] The detergent compositions herein can contain aluminosilicates which have already
been described in detail herein.
[0062] The granular detergents of the present invention can contain neutral or alkaline
salts which have a pH in solution of seven or greater, and can be either organic or
inorganic in nature. The builder salt assists in providing the desired density and
bulk to the detergent granules herein. While some of the salts are inert, many of
them also function as detergency builder materials in the laundering solution.
[0063] Examples of neutral water-soluble salts include the alkali metal, ammonium or substituted
ammonium chlorides, fluorides and sulfates. The alkali metal, and especially sodium,
salts of the above are preferred. Sodium sulfate is typically used in detergent granules
and is a particularly preferred salt. Citric acid and, in general, any other organic
or inorganic acid may be incorporated into the granular detergents of the present
invention as long as it is chemically compatible with the rest of the agglomerate
composition.
[0064] Other useful water-soluble salts include the compounds commonly known as detergent
builder materials. Builders are generally selected from the various water-soluble,
alkali metal, ammonium or substituted ammonium phosphates, polyphosphates, phosphonates,
polyphosphonates, carbonates, silicates, borates, and polyhyroxysulfonates. Preferred
are the alkali metal, especially sodium, salts of the above.
[0065] Specific examples of inorganic phosphate builders are sodium and potassium tripolyphosphate,
pyrophosphate, polymeric metaphosphate having a degree of polymerization of from about
6 to 21, and orthophosphate. Examples of polyphosphonate builders are the sodium and
potassium salts of ethylene diphosphonic acid, the sodium and potassium salts of ethane
1-hydroxy-1,1-diphosphonic acid and the sodium and potassium salts of ethane, 1,1,2-triphosphonic
acid. Other phosphorus builder compounds are disclosed in U.S. Pat. Nos. 3,159,581;
3,213,030; 3,422,021; 3,422,137; 3,400,176 and 3,400,148.
[0066] Examples of nonphosphorus, inorganic builders are sodium and potassium carbonate,
bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicate. (Suitable silicates
having been described above).
Polymers
[0067] Also useful are various organic polymers, some of which also may function as builders
to improve detergency. Included among such polymers may be mentioned sodium carboxy-lower
alkyl celluloses, sodium lower alkyl celluloses and sodium hydroxy-lower alkyl celluloses,
such as sodium carboxymethyl cellulose, sodium methyl cellulose and sodium hydroxypropyl
cellulose, polyvinyl alcohols (which often also include some polyvinyl acetate), polyacrylamides,
polyacrylates and various copolymers, such as those of maleic and acrylic acids. Molecular
weights for such polymers vary widely but most are within the range of 2,000 to 100,000.
[0068] Polymeric polycarboxyate builders are set forth in U.S. Patent 3,308,067, Diehl,
issued March 7, 1967. Such materials include the water-soluble salts of homo-and copolymers
of aliphatic carboxylic acids such as maleic acid, itaconic acid, mesaconic acid,
fumaric acid, aconitic acid, citraconic acid and methylenemalonic acid.
Other Optional Ingredients
[0069] Other ingredients commonly used in detergent compositions can be included in the
compositions of the present invention. These include flow aids, color speckles, bleaching
agents and bleach activators, suds boosters or suds suppressors, antitarnish and anticorrosion
agents, soil suspending agents, soil release agents, dyes, fillers, optical brighteners,
germicides, pH adjusting agents, nonbuilder alkalinity sources, hydrotropes, enzymes,
enzyme-stabilizing agents, chelating agents and perfumes.
[0070] Particulate suds suppressors may also be incorporated in the finished composition
by mixing according to the present invention. Preferably the suds suppressing activity
of these particles is based on fatty acids or silicones.
Examples
[0071] The following silicate particles (comprising montmorillonite clay) were made by spraying
an aqueous solution (40%) of sodium silicate with glycerol, on to a montmorillonite
clay in a Loedige mixer.
[0072] The resulting wet agglomerates were dried to a moisture level of 8% in a fluid bed
dryer.
[0073] All of the percentages given below are by weight of the finshed product composition
Example |
1 |
2 |
3 (Comparative) |
Montmorillonite clay |
77.2 |
77.2 |
88.6 |
Sodium Silicate, 2.4 ratio |
- |
11.9 |
- |
Sodium Silicate, 3.2 ratio |
11.9 |
- |
- |
Glycerol |
2.9 |
2.9 |
3.4 |
Moisture |
8 |
8 |
8 |
[0074] In examples 4, 5 and 7-10, finished compositions were made using the agglomerated
clay particles of examples 1 to 3, and which further comprised particulate sodium
percarbonate.
[0075] The following abbreviations have been used in the following examples:
LAS |
C13 linear alkyl benzene sulphonate |
C16-18 AS |
C16-18 alkyl sulphate |
C14-15 AS |
C14-15 alkyl sulphate |
C12-15 AE3S |
C12-15 alkyl ether sulphate with an average of 3 ethoxy groups per mole |
C14-15AE7 |
Ethoxylated nonionic surfactant having a C14-15 alkyl chain and an average of 7 ethoxy
groups per mole |
C12-13AE3 |
Ethoxylated nonionic surfactant having a C12-13 alkyl chain and an average of 3 ethoxy
groups per mole |
Cationic Surfactant |
Mono alkyl (C13-15) monoethoxy dimethyl ammonium chloride |
SKS-6
(Trade Name) |
Layered silicate (supplied by Hoechst) |
TAED |
N,N,N,N-Tetraacetylethylene diamine |
PEG |
Polyethylene glycol with a molecular weight of 4 000 000. |
Enzymes |
A mixture of Savinase (having an activity of 4.0 KNPU/g) at a level of 1.4% by weight
of the finished composition; and lipolase (having an activity of 100 000 LU/g) at
a level of 0.4 % by weight of the finished product. |
Percarbonate particles |
Particulate sodium percarbonate. The percarbonate was coated with a mixture of carbonate
and sulphate (carbonate : Sulphate ratio = 2.5:1). The coating material being used
at a level of 2.5% by weight of the percarbonate. The mean particle size of the coated
percarbonate was 580 micrometers. |
Examples |
4 |
5 |
6 (Comparative) |
7 (Comparative) |
LAS: |
7 |
7 |
7 |
7 |
C16-18 AS: |
1.5 |
1.5 |
1.5 |
1.5 |
C14-15 AS: |
2 |
2 |
2 |
2 |
Cationic Surfactant: |
1.5 |
1.5 |
1.5 |
1.5 |
Zeolite 4A |
17 |
17 |
17 |
17 |
Citrate |
5 |
5 |
5 |
5 |
Silicate (2 Ratio) |
3 |
3 |
4.8 |
4.8 |
Copolymer Acrylic/Maleic |
4 |
4 |
4 |
4 |
Phosphonate |
0.4 |
0.4 |
0.4 |
0.4 |
Carbonate |
15 |
15 |
28.5 |
15 |
PEG |
0.5 |
0.5 |
0.5 |
0.5 |
Enzymes |
1.8 |
1.8 |
1.8 |
1.8 |
TAED |
3.5 |
3.5 |
3.5 |
3.5 |
Percarbonate |
13 |
13 |
13 |
13 |
Clay Particles |
15.5 |
15.5 |
- |
13.5 |
Clay Particles |
|
|
|
|
used from |
Example 1 |
Example 2 |
- |
Example 3 |
Water/Miscellaneous |
--------- Balance to 100% ---------- |
[0076] A two kg. sample of each of the examples 4 to 7 was packed in a closed carton and
stored at 40°C and at 32°C/80% relative humidity. The remaining percarbonate (hydrogen
peroxide) was measured after 4 weeks storage.
Example 7 shows a Percarbonate stability considerably poorer than Example 6 which
reflects the detrimental effect of clay particles. Example 5, which contains clay/silicate
particles, shows a Percarbonate stability comparable to Example 6, and much better
than Example 7. Example 4 shows the best Percarbonate stability of these examples.
Examples |
8 |
9 |
10 |
C14-15 AS: |
8 |
8 |
8 |
C12-15 AE3S: |
1.7 |
1.7 |
1.7 |
C14-15AE7: |
6 |
1.3 |
6 |
C12-13AE3: |
- |
2.6 |
- |
C16-18 N-methyl glucamide |
- |
2.6 |
- |
Cationic Surfactant: |
2 |
2 |
2 |
Zeolite 4A |
12 |
12 |
12 |
Citrate |
0.8 |
0.8 |
0.6 |
SKS-6 (Trade Name) |
8 |
8 |
8 |
Copolymer Acrylic/Maleic |
4 |
4 |
6.6 |
Phosphonate |
0.2 |
0.2 |
0.2 |
Bicarbonate |
- |
2.7 |
- |
Carbonate |
14 |
14 |
14 |
PEG |
0.5 |
0.5 |
0.5 |
Enzymes |
1.8 |
1.8 |
1.8 |
TAED |
4.5 |
4.5 |
6 |
Percarbonate |
13.3 |
13.3 |
17 |
Clay Particles |
13.6 |
13.6 |
16.5 |
Clay Particles used from: |
Example 2 |
Example 2 |
Example 2 |
Water/Miscellaneous |
---------Balance to 100% ------ |
[0077] The compositions of examples 8 to 10 show good percarbonate stability (less than
20% hydrogen peroxide loss after 2 weeks storage at 32°C and 80% relative humidity
in closed cartons).