[0001] The present invention is concerned with granular detergent components or compositions
which are rich in high performance nonionic surfactants. The compositions are based
upon specified surfactant systems and processes which make it possible to produce
very high surfactant active components.
[0002] Nonionic surfactants are important components of current laundry detergent compositions.
Present trends demand particulate components or compositions which have a high bulk
density and which have a high level of nonionic surfactant. The particulate must have
good physical characteristics, and must deliver nonionic surfactants which have been
selected for high performance in to the wash. Various prior art attempts have been
described which approach these demands from different perspectives. For example:
[0003] EP544492, published on 2nd June, 1993, discloses particulate high density detergent
composition comprising 15 to 50% of a mixed anionic/nonionic surfactant system. The
nonionic surfactants chosen are ethoxylated alcohols having a peaked ethoxylation
distribution with an average of about 3 to 6.5. Although fatty acid soaps are suggested
as suitable structurants which modify the surfactant viscosity profile, the resulting
granules where soap is used (in Examples 16 to 19, 24 to 29) have surfactant activities
of 29 to 32.5 %.
[0004] WO9206160, published on 16th April, 1992, discloses high performing nonionic surfactant
systems based on mixtures of glucose amides and ethoxylated nonionic surfactants.
In one example (example 20) a component is described which comprises a nonionic surfactant
system which is a mixture of 20% Dobanol (Trade Name) EO3 and 80% N-methyl glucose
amide in aqueous solution.
[0005] EP364881, published on 25th April 1990, describes gels formed from polyglycol ether
derivatives and water in ratios of from 5:1 to 1:2. The gels are formed into free-flowing
granulates by mixing with finely divided solids.
[0006] The problem addressed by the present invention concerns the need to provide high
density particulate laundry detergent which has a high nonionic surfactant content,
and which does not cake or lump upon storage, even in hot, humid conditions, and which
dissolves and disperses rapidly upon contact with water, even cold water, to give
a high detergency performance on the washing load.
[0007] Whilst the prior art provides some guidance as to how each of these objectives might
be independently achieved, there does not appear to be a solution to all of the aspects
of the problem provided by any one reference.
[0008] The present invention provides a nonionic, or mixed nonionic/anionic, surfactant
system having a specific viscosity profile which can be formed into a solid particulate
which does not cake during storage, which dissolves rapidly and has an excellent performance
profile.
Summary of the Invention
[0009] In a first aspect, the present invention concerns a granular detergent composition
or component having a bulk density of at least 650 g/l, comprising a surfactant system
wherein said composition or component comprises from 35% to 85% by weight of nonionic
surfactant and wherein said surfactant system is substantially in the solid phase
at temperatures of 25°C and below, and that said surfactant system has a softening
point above 25°C and wherein the surfactant system has a viscosity profile whereby
the viscosity of the surfactant system is at least 20000 cps at a temperature of 10°C
above the softening point, and less than 10000 cps at a temperature of 30°C above
the softening point, all viscosities being measured at a shear rate of 25s⁻¹.
[0010] In a second aspect the present invention concerns specific combinations of the nonionic
surfactant containing particle with other detergent components to produce a finished
laundry detergent composition.
[0011] In a third aspect the present invention concerns a process for the manufacture of
nonionic surfactant containing particles of the present invention.
Detailed Description of the Invention
[0012] It has now been found that high surfactant activities can be achieved if an agglomeration
"window" exists within which the surfactant system has a high viscosity. Typically
this may be achieved by appropriate selection of nonionic surfactants such that there
is a "window" of at least 10°C, the lower limit of which is the softening point of
the surfactant system, within which the system has a viscosity of at least 20000cps,
preferably 25000 to 50000cps.
[0013] However, in order to be able to prepare, handle, store and transport the surfactant
system it should have a viscosity of less than 10000cps at a temperature of 30°C above
the softening point.
[0014] High activities and good caking properties can only be achieved if the surfactant
system has a softening point above ambient temperature, e.g. above 25°C, preferably
above 40°C.
[0015] Good rates of solubility can be correlated with the softening point of the surfactant
system. Surfactant systems having a softening point of greater than 100°C (e.g. "pure"
C16 N-methyl glucosamide) tend to show poor rates of solubility. Preferably the softening
point of the surfactant system will be less than 80°C.
[0016] It is preferred that the surfactant system of the present invention has a softening
point which lies within the range of from 40°C to 100°C, and furthermore that the
surfactant system has a viscosity profile whereby the viscosity of the surfactant
system is from 25000 to 50000 cps at a temperature of 10°C above the softening point.
[0017] The surfactant system may be comprised entirely of nonionic surfactants or, preferably,
it will be a mixed anionic/nonionic surfactant system. In either case the surfactant
system preferably comprises more than 40% by weight, and more preferably more than
50% by weight of nonionic surfactant. Where anionic surfactant is present in the surfactant
system the ratio of anionic to nonionic surfactant should be from 1:100 to 1:1.
[0018] Where the surfactant system is exclusively nonionic surfactant it is often possible
to exclude water completely. However when anionic surfactants are present these will
often be used in the form of a concentrated paste, or, more preferably, in the form
of a hydrated or moisture containing powder. The surfactant system should have a water
component of less than 15%, preferably less than 10% by weight, and most preferably
less than 5% by weight of the surfactant system.
[0019] Preferred nonionic surfactants may be selected from the families of ethoxylated nonionic
surfactants, glycerol ethers, glucosamides, glycerol amides,glycerol esters, fatty
acids, fatty acid esters, fatty amides, alkyl polyglucosides, alkyl polyglycol ethers,
polyethylene glycols, ethoxylated alkyl phenols and mixtures thereof. A highly preferred
surfactant system comprises a mixture of polyhydroxy fatty acid amide and an ethoxylated
nonionic surfactant in the ratio of from 3:7 to 7:3.
[0020] Finished laundry detergent compositions may be prepared by mixing or blending the
nonionic containing particles with:
a) a component which comprises at least 40% by weight of anionic surfactant; and
b) a component which comprises at least 70% by weight of a builder material.
Preferably each of these major components is present at a level of from 3% to 40%
by weight of the finished component. More preferably component (b) is present at a
level of from 3% to 20% by weight of the finished composition.
[0021] The nonionic surfactant containing particles of the present invention may be prepared
by:
a) pumping a surfactant system in its low viscosity state;
b) cooling said nonionic surfactant to a temperature where its viscosity is increased
to at least 20000 cps;
c) granulating the surfactant in the presence of a finely divided powder;
d) cooling said agglomerates.
[0022] The cooling step (b) is preferably performed using a high pressure scraped surface
heat exchanger.
[0023] The term "surfactant system" as used herein means a mixture of one or more surfactants
comprising nonionic surfactants alone or a mixed anionic/nonionic surfactant system.
Whilst other components such as water and solvents (e.g. short chain alcohols) may
be present in the surfactant system, these will generally be minimised and preferably
excluded.
[0024] The term "softening point" as used herein means the temperature at which the surfactant
system passes between the solid and mixed solid/liquid phases. The softening point
can be identified by using a differential scanning calorimetry (DSC) curve. The curve
is a plot of true specific heat capacity against temperature. The softening point
is the temperature at which enthalpy of melting is greater than zero. This is the
temperature at which phase change begins to occur when the solid surfactant system
is heated.
[0025] The term "viscosity" as used herein means the viscosity measured at a shear rate
of 25s⁻¹ . The viscosity can be measured by rotational analysis (e.g. a rheometer).
Suitable instruments for these measurements are manufactured by Physica Messtechnik,
Germany, (supplied by Thermo Instrument Systems of Breda, Netherlands).
[0026] The term "high active" as used herein refers to nonionic surfactant activities of
at least 35% by weight of the particulate component or composition, preferably greater
than 40% by weight, and more preferably about 50% by weight.
[0027] The various aspects of the invention will now be described in more detail.
Surfactant Systems
[0028] In order to provide a surfactant system which fulfils all of the physical requirements
(ie the viscosity profile) of the present invention, it will usually be necessary
to blend two or more compatible nonionic surfactants to give the required properties.
For example, a homogeneous mixture of a high melting point surfactant with a low melting
point surfactant, in suitable proportions, will give a surfactant system having the
desired softening point.
[0029] While any nonionic surfactant may be usefully employed in the present invention,
two families of nonionics have been found to be particularly useful. These are nonionic
surfactants based on alkoxylated (especially ethoxylated) alcohols, and those nonionic
surfactants based on amidation products of fatty acid esters and N-alkyl polyhydroxy
amine. The amidation products of the esters and the amines are generally referred
to herein as polyhydroxy fatty acid amides. Particularly useful in the present invention
are mixtures comprising two or more nonionic surfactacts wherein at least one nonionic
surfactant is selected from each of the groups of alkoxylated alcohols and the polyhydroxy
fatty acid amides.
[0030] Suitable nonionic surfactants 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.
[0031] Particularly preferred for use in the present invention are nonionic surfactants
such as 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 about
4 to 25 moles of ethylene oxide per mole of alkyl phenol.
[0032] 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 an average of up to 25 moles of ethylene oxide per more of alcohol. Particularly
preferred are the condensation products of alcohols having an alkyl group containing
from about 9 to 15 carbon atoms with from about 2 to 10 moles of ethylene oxide per
mole of alcohol; and condensation products of propylene glycol with ethylene oxide.
Most preferred are condensation products of alcohols having an alkyl group containing
from about 12 to 15 carbon atoms with an average of about 3 moles of ethylene oxide
per mole of alcohol.
[0033] It is a particularly preferred embodiment of the present invention that the nonionic
surfactant system also includes a polyhydroxy fatty acid amide component.
[0034] Polyhydroxy fatty acid amides may be produced by reacting a fatty acid ester and
an N-alkyl polyhydroxy amine. The preferred amine for use in the present invention
is N-(R1)-CH2(CH2OH)4-CH2-OH, where R1 is typically a alkyl, e.g. methyl group; and
the preferred ester is a C12-C20 fatty acid methyl ester.
[0035] Methods of manufacturing polyhydroxy fatty acid amides have been described in WO
92 6073, published on 16th April, 1992. This application describes the preparation
of polyhydroxy fatty acid amides in the presence of solvents. In a highly preferred
embodiment of the invention N-methyl glucamine is reacted with a C12-C20 methyl ester.
It also says that the formulator of granular detergent compositions may find it convenient
to run the amidation reaction in the presence of solvents which comprise alkoxylated,
especially ethoxylated (EO 3-8) C12-C14 alcohols (page 15, lines 22-27). This can
directly yield nonionic surfactant systems which are preferred in the present invention,
such as those comprising N-methyl glucosamide and C12-C14 alcohols with an average
of 3 ethoxylate groups per molecule.
[0036] Nonionic surfactant systems, and granular detergents made from such systems have
been described in WO 92 6160, published on 16th April, 1992. This application describes
(example 15) a granular detergent composition prepared by fine dispersion mixing in
an Eirich RV02 mixer which comprises N-methyl glucosamide (10%), nonionic surfactant
(10%).
[0037] Both of these patent applications describe nonionic surfactant systems together with
suitable manufacturing processes for their synthesis, which have been found to be
suitable for use in the present invention. However, for the purposes of the present
invention is necessary to minimise (and preferably exclude) the presence of water
(or other solvents) in order to achieve the required viscosity profile of the surfactant
system of the present invention.
[0038] Other nonionic surfactants which may be used as components of the surfactant systems
herein include ethoxylated nonionic surfactants, glycerol ethers, glucosamides, glycerol
amides,glycerol esters, fatty acids, fatty acid esters, fatty amides, alkyl polyglucosides,
alkyl polyglycol ethers, polyethylene glycols, ethoxylated alkyl phenols and mixtures
thereof.
[0039] The surfactant system may also comprise anionic surfactants, indeed the inclusion
of such surfactants may be of considerable advantage in order to improve the rate
of solubility of the granular surfactant.
Anionic Surfactants
[0040] The laundry detergent compositions of the present invention can contain, in addition
to the nonionic surfactant system of the present invention, one or more anionic surfactants
as described below.
Alkyl Ester Sulfonate Surfactant
[0042] Alkyl Ester sulfonate surfactants hereof include linear esters of C₈-C₂₀ carboxylic
acids (i.e. fatty acids) which are sulfonated with gaseous SO₃ according to "The Journal
of the American oil Chemists Society'" 52 (1975), pp. 323-329. Suitable starting materials
would include natural fatty substances as derived from tallow, palm oil, etc.
[0043] The preferred alkyl ester sulfonate surfactant, especially for laundry applications,
comprises alkyl ester sulfonate surfactants of the structural formula:

wherein R³ is a C₈-C₂₀ hydrocarbyl, preferably an alkyl, or combination thereof, R⁴
is a C₁-C₆ hydrocarbyl, preferably an alkyl, or combination thereof, and M is a cation
which forms a water soluble salt with the alkyl ester sulfonate. Suitable salt-forming
cations include metals such as sodium, potassium, and lithium, and substituted or
unsubstituted ammonium cations, such as monoethanolamine, diethanolamine, and triethanolamine.
Preferably, R³ is C₁₀-C₁₆ alkyl, and R⁴ is methyl, ethyl or isopropyl. Especially
preferred are the methyl ester sulfonates wherein R³ is C₁₄-C₁₆ alkyl.
Alkyl Sulfate Surfactant
[0044] Alkyl sulfate surfactants hereof are water soluble salts or acids or the formula
ROSO₃M wherein R preferably is a C₁₀-C₂₄ hydrocarbyl, preferably an alkyl or hydroxyalkyl
having a C₁₀-C₂₀ alkyl component, more preferably a C₁₂-C₁₈ alkyl or hydroxyalkyl,
and M is H or a cation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium),
or ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium
cations and quaternary ammonium cations, such as tetramethyl-ammonium and dimethyl
piperdinium cations and quarternary ammonium cations derived from alkylamines such
as ethylamine, diethylamine, triethylamine, and mixtures thereof, and the like). Typically,
alkyl chains of C₁₂₋₁₆ are preferred for lower wash temperatures (e.g., below about
50°C) and C₁₆₋₁₈ alkyl chains are preferred for higher wash temperatures (e.g., above
about 50°C).
Alkyl Alkoxylated Sulfate Surfactant
[0045] Alkyl alkoxylated sulfate surfactants hereof are water soluble salts or acids
of the formula RO(A)
mSO₃M wherein R is an unsubstituted C₁₀-C₂₄ alkyl or hydroxyalkyl group having a C₁₀-C₂₄
alkyl component, preferably a C₁₂-C₂₀ alkyl or hydroxyalkyl, more preferably C₁₂-C₁₈
alkyl or hydroxyalkyl, A is an ethoxy or propoxy unit, m is greater than zero, typically
between about 0.5 and about 6, more preferably between about 0.5 and about 3, and
M is H or a cation which can be, for example, a metal cation (e.g., sodium, potassium,
lithium, calcium, magnesium, etc.), ammonium or substituted-ammonium cation. Alkyl
ethoxylated sulfates as well as alkyl propoxylated sulfates are contemplated herein.
Specific examples of substituted ammonium cations include methyl-, dimethyl-, trimethylammonium
and quaternary ammonium cations, such as tetramethyl-ammonium, dimethyl piperdinium
and cations derived from alkanolamines such as ethylamine, diethylamine, triethylamine,
mixtures thereof, and the like. Exemplary surfactants are C₁₂-C₁₈ alkyl ether (1.0)
sulfate, C₁₂-C₁₈ alkyl ether (2.25) sulfate, C₁₂-C₁₈ alkyl ether (3.0) sulfate, and
C₁₂-C₁₈ alkyl ether (4.0) sulfate, wherein the counterion is conveniently selected
from sodium and potassium.
Other Anionic Surfactants
[0046] Other anionic surfactants useful for detersive purposes can also be included in
the laundry detergent compositions of the present invention. These can include salts
(including, for example, sodium, potassium, ammonium, and substituted ammonium salts
such as mono-, di- and triethanolamine salts) of soap, C₉-C₂₀ linear alkylbenzenesulphonates,
C₈-C₂₂ primary or secondary alkanesulphonates, C₈-C₂₄ olefinsulphonates, sulphonated
polycarboxylic acids prepared by sulphonation of the pyrolyzed product of alkaline
earth metal citrates, e.g., as described in British patent specification No. 1,082,179,
C₈-C₂₄ alkylpolyglycolethersulfates (containing up to 10 moles of ethylene oxide);
methyl ester sulphonates (MES); acyl glycerol sulfonates, fatty oleyl glycerol sulfates,
alkyl phenol ethylene oxide ether sulfates, paraffin sulfonates, alkyl phosphates,
isethionates such as the acyl isethionates, N-acyl taurates, alkyl succinamates and
sulfosuccinates, monoesters of sulfosuccinate (especially saturated and unsaturated
C₁₂-C₁₈ monoesters) diesters of sulfosuccinate (especially saturated and unsaturated
C₆-C₁₄ diesters), acyl sarcosinates, sulfates of alkylpolysaccharides such as the
sulfates of alkylpolyglucoside, branched primary alkyl sulfates, alkyl polyethoxy
carboxylates such as those of the formula RO(CH₂CH₂O)
kCH₂COO-M⁺ wherein R is a C₈-C₂₂ alkyl, k is an integer from 0 to 10, and M is a soluble
salt-forming cation. Resin acids and hydrogenated resin acids are also suitable, such
as rosin, hydrogenated rosin, and resin acids and hydrogenated resin acids present
in or derived from tall oil. Further examples are given in "Surface Active Agents
and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants
are also generally disclosed in U.S. Patent 3,929,678, issued December 30, 1975 to
Laughlin, et al. at Column 23, line 58 through Column 29, line 23 (herein incorporated
by reference).
When included therein, the laundry detergent compositions of the present invention
typically comprise from about 1 % to about 40 %, preferably from about 3 % to about
20 % by weight of such anionic surfactants.
Other Surfactants
[0047] The laundry detergent compositions of the present invention may also contain cationic,
ampholytic, zwitterionic, and semi-polar surfactants.
[0048] Cationic detersive surfactants suitable for use in the laundry detergent compositions
of the present invention are those having one long-chain hydrocarbyl group. Examples
of such cationic surfactants include the ammonium surfactants such as alkyldimethylammonium
halogenides, and those surfactants having the formula :
[R²(0R³)y][R⁴(OR³)y]₂R⁵N+X-
wherein R2 is an alkyl or alkyl benzyl group having from about 8 to about 18 carbon
atoms in the alkyl chain, each R³ is selected from the group consisting of -CH₂CH₂-,
-CH₂CH(CH₃)-, -CH₂CH(CH₂OH)-, -CH₂CH₂CH₂-, and mixtures thereof; each R⁴ is selected
from the group consisting of C₁-C₄ alkyl, C₁-C₄ hydroxyalkyl, benzyl ring structures
formed by joining the two R⁴ groups,
-CH₂COH-CHOHCOR⁶CHOHCH₂OH wherein R⁶ is any hexose or hexose polymer having a molecular
weight less than about 1000, and hydrogen when y is not 0; R⁵ is the same as R⁴ or
is an alkyl chain wherein the total number of carbon atoms of R² plus R⁵ is not more
than about 18; each y is from 0 to about 10 and the sum of the y values is from 0
to about 15; and X is any compatible anion.
[0049] Other cationic surfactants useful herein are also described in US Patent 4,228,044,
Cambre, issued October 14, 1980, incorporated herein by reference.
[0050] When included therein, the laundry detergent compositions of the present invention
typically comprise from 0 % to about 25 %, preferably form about 3 % to about 15 %
by weight of such cationic surfactants.
[0051] Ampholytic surfactants are also suitable for use in the laundry detergent compositions
of the present invention. These surfactants can be broadly described as aliphatic
derivatives of secondary or tertiary amines, or aliphatic derivatives of heterocyclic
secondary and tertiary amines in which the aliphatic radical can be straight- or branched
chain. One of the aliphatic substituents contains at least 8 carbon atoms, typically
from about 8 to about 18 carbon atoms, and at least one contains an anionic water-solubilizing
group e.g. carboxy, sulfonate, sulfate. See U.S. Patent No. 3,929,678 to Laughlin
et al., issued December 30, 1975 at column 19, lines 18-35 (herein incorporated by
reference) for examples of ampholytic surfactants.
[0052] When included therein, the laundry detergent compositions of the present invention
typically comprise form 0 % to about 15 %, preferably from about 1 % to about 10 %
by weight of such ampholytic surfactants.
[0053] Zwitterionic surfactants are also suitable for use in laundry detergent compositions.
These surfactants can be broadly described as derivatives of secondary and tertiary
amines, derivates of heterocyclic secondary and tertiary amines, or derivatives of
quaternary ammonium, quarternary phosphonium or tertiary sulfonium compounds. See
U.S. Patent No. 3,929,678 to Laughlin et al., issued December 30, 1975 at columns
19, line 38 through column 22, line 48 (herein incorporated by reference) for examples
of zwitterionic surfactants.
[0054] When included therein, the laundry detergent compositions of the present invention
typically comprise form 0 % to about 15 %, preferably from about 1 % to about 10 %
by weight of such zwitterionic surfactants.
[0055] Semi-polar nonionic surfactants are a special category of nonionic surfactants which
include water-soluble amine oxides containing one alkyl moiety of from about 10 to
about 18 carbon atoms and 2 moieties selected from the group consisting af alkyl groups
and hydrocyalkyl groups containing form about 1 to about 3 carbon atoms; water-soluble
phosphine oxides containing one alkyl moiety of form about 10 to about 18 carbon atoms
and 2 moieties selected form the group consisting of alkyl groups and hydroxyalkyl
groups containing from about 1 to about 3 carbon atoms.
[0056] Semi-polar nonionic detergent surfactants include the amine oxide surfactants having
the formula :

wherein R³ is an alkyl, hydroxyalkyl, or alkyl phenyl group or mixtures thereof containing
from about 8 to about 22 carbon atoms; R⁴ is an alkylene or hydroxyalkylene group
containing from about 2 to about 3 carbon atoms or mixtures thereof; x is form 0 to
about 3; and each R⁵ is an alkyl or hydroxyalkyl group containing form about 1 to
about 3 carbon atoms or a polyethylene oxide group containing from about 1 to about
3 ethylene oxide groups. The R⁵ groups can be attached to each other, e.g., through
an oxygen or nitrogen atom, to form a ring structure.
[0057] There amine oxide surfactants in particular include C₁₀-C₁₈ alkyl dimenthyl amine
oxides and C₈-C₁₂ alkoxy ethyl dihydroxy ethyl amine oxides.
[0058] When included therein, the laundry detergent compositions of the present invention
typically comprise form 0 % to about 15 %, preferably from about 1 % to about 10 %
by weight of such semi-polar nonionic surfactants.
[0059] Normally the granular components and compositions will also contain other optional
ingredients, such as builders, chelants (including phosphonic acids, succinic acids
and their salts), bleaches, bleach activators (such as tetraacetylethylene diamine),
polymers and co-polymers. Examples of such ingredients which are commonly used in
detergents are given in more detail hereinbelow.
[0060] The detergent compositions herein can contain crystalline aluminosilicate ion exchange
material of the formula
Na
z[(AlO₂)
z·(SiO₂)
y]·xH₂O
wherein z and y are at least about 6, the molar ratio of z to y is from about 1.0
to about 0.4 and z is from about 10 to about 264. Amorphous hydrated aluminosilicate
materials useful herein have the empirical formula
M
z(zAlO₂·ySiO₂)
wherein M is sodium, potassium, ammonium or substituted ammonium, z is from about
0.5 to about 2 and y is 1, said material having a magnesium ion exchange capacity
of at least about 50 milligram equivalents of CaCO₃ hardness per gram of anhydrous
aluminosilicate. Hydrated sodium Zeolite A with a particle size of from about 1 to
10 microns is preferred.
The aluminosilicate ion exchange builder materials herein are in hydrated form
and contain from about 5% to about 28% of water by weight if crystalline, and potentially
even higher amounts of water if amorphous. Highly preferred crystalline aluminosilicate
ion exchange materials contain from about 18% to about 22% water in their crystal
matrix. The crystalline aluminosilicate ion exchange materials are further characterized
by a particle size diameter of from about 0.1 micron to about 10 microns. Amorphous
materials are often smaller, e.g., down to less than about 0.01 micron. Preferred
ion exchange materials have a particle size diameter of from about 0.2 micron to about
4 microns. 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 about 200 mg equivalent of CaCO₃ water hardness/g of aluminosilicate,
calculated on an anhydrous basis, and which generally is in the range of from about
300 mg eq./g to about 352 mg eq./g. The aluminosilicate ion exchange materials herein
are still further characterized by their calcium ion exchange rate which is at least
about 2 grains Ca⁺⁺/gallon/minute/gram/gallon of aluminosilicate (anhydrous basis),
and generally lies within the range of from about 2 grains/gallon/minute/gram/gallon
to about 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
about 4 grains/gallon/minute/gram/gallon.
The amorphous aluminosilicate ion exchange materials usually have a Mg⁺⁺ exchange
of at least about 50 mg eq. CaCO₃/g (12 mg Mg⁺⁺/g) and a Mg⁺⁺ exchange rate of at
least about 1 grain/gallon/minute/gram/gallon. Amorphous materials do not exhibit
an observable diffraction pattern when examined by Cu radiation (1.54 Angstrom Units).
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, incorporated herein
by reference. Preferred synthetic crystalline aluminosilicate ion exchange materials
useful herein are available under the designations Zeolite A, Zeolite B, and Zeolite
X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange
material has the formula
Na₁₂[(AlO₂)₁₂(SiO2)₁₂]·xH₂O
wherein x is from about 20 to about 30, especially about 27 and has a particle size
generally less than about 5 microns.
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.
Examples of neutral water-soluble salts include the alkali metal, ammonium or substituted
ammonium chlorides, fluorides and sulfates. The alkali and alkaline earth metal, and
especially sodium and magnesium, 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.
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 polyhydroxysulfonates. Preferred
are the alkali metal, especially sodium, salts of the above.
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, incorporated herein by reference.
Examples of nonphosphorus, inorganic builders are sodium and potassium carbonate,
bicarbonate, sesquicarbonate, tetraborate decahydrate, and silicate.
[0061] Suitable silicates are those having an SiO₂:Na₂O ratio in the range from 1.6 to 3.4,
the so-called amorphous silicates of SiO₂ : Na₂O ratios from 2.0 to 2.8 being preferred.
These materials can be added at various points of the manufacturing process, such
as in the form of an aqueous solution serving as an agglomerating agent for other
solid components, or, where the silicates are themselves in particulate form, as solids
to the other particulate components of the composition.
[0062] Within the silicate class, highly preferred materials are crystalline layered sodium
silicates of general formula
NaMSi
xO
2x+1.yH₂O
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-0164514
and methods for their preparation are disclosed in DE-A-3417649 and DE-A-3742043.
For the purposes 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 0 and preferred
examples of this formula comprise the γ and δ forms of Na₂Si₂O₅. These materials are
available from Hoechst AG FRG as respectively NaSKS-11 and NaSKS-6. The most preferred
material is δ -Na₂Si₂O₅, (NaSKS-6). Crystalline layered silicates are incorporated
either as dry mixed solids, or as solid components of agglomerates with other components.
[0063] As mentioned above powders normally used in detergents such as zeolite, carbonate,
silica, silicate, citrate, phosphate, perborate, percarbonate etc. and process acids
such as starch and sugars, can be used in preferred embodiments of the present invention.
Optionally, other components may be added at any one of the stages of the process
of the present invention, or they may be mixed with or sprayed on to the granular
detergents of the present invention.
[0064] Polymers which are particularly useful in the present invention include 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), polyvinyl
pyrrolidone, polyethylene glycol, polyaspartate, 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.
[0065] Most preferred are 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.
[0066] Another optional detergent composition ingredient is a suds suppressor, exemplified
by silicones, and silica-silicone mixtures. Silicones can be generally represented
by alkylated polysiloxane materials while silica is normally used in finely divided
forms, exemplified by silica aerogels and xerogels and hydrophobic silicas of various
types. These materials can be incorporated as particulates in which the suds suppressor
is advantageously releasably incorporated in a water-soluble or water-dispersible,
substantially non-surface-active detergent-impermeable carrier. Alternatively the
suds suppressor can be dissolved or dispersed in a liquid carrier and applied by spraying
on to one or more of the other components.
[0067] As mentioned above, useful silicone suds controlling agents can comprise a mixture
of an alkylated siloxane, of the type referred to hereinbefore, and solid silica.
Such mixtures are prepared by affixing the silicone to the surface of the solid silica.
A preferred silicone suds controlling agent is represented by a hydrophobic silanated
(most preferably trimethyl-silanated) silica having a particle size in the range from
10 nanometers to 20 nanometers and a specific surface area above 50 m²/g, intimately
admixed with dimethyl silicone fluid having a molecular weight in the range from about
500 to about 200,000 at a weight ratio of silicone to silanated silica of from about
1:1 to about 1:2.
[0068] A preferred silicone suds controlling agent is disclosed in Bartollota et al. US
Patent 3,933,672. Other particularly useful suds suppressors are the self-emulsifying
silicone suds suppressors, described in German Patent Application DTOS 2,646,126 published
April 28, 1977. An example of such a compound is DC0544, commercially available from
Dow Corning, which is a siloxane/glycol copolymer.
[0069] The suds suppressors described above are normally employed at levels of from 0.001%
to 0.5% by weight of the composition, preferably from 0.01% to 0.1% by weight.
[0070] The preferred methods of incorporation comprise either application of the suds suppressors
in liquid form by spray-on to one or more of the major components of the composition
or alternatively the formation of the suds suppressors into separate particulates
that can then be mixed with the other solid components of the composition. The incorporation
of the suds modifiers as separate particulates also permits the inclusion therein
of other suds controlling materials such as C₂₀-C₂₄ fatty acids, microcrystalline
waxes and high MWt copolymers of ethylene oxide and propylene oxide which would otherwise
adversely affect the dispersibility of the matrix. Techniques for forming such suds
modifying particulates are disclosed in the previously mentioned Bartolotta et al
US Patent No. 3,933,672.
[0071] Another optional ingredient useful in the present invention is one or more enzymes.
[0072] Preferred enzymatic materials include the commercially available amylases, neutral
and alkaline proteases, lipases, esterases and cellulases conventionally incorporated
into detergent compositions. Suitable enzymes are discussed in US Patents 3,519,570
and 3,533,139.
Finished product compositions
[0073] The nonionic containing particles of the present invention can be effectively combined
with other ingredients to form a multi-purpose granular detergent. In particular,
the finished detergent composition should include detergent ingredients such as those
described above. In finishing a product, the nonionic surfactant particles can be
simply mixed with the rest of the ingredients that are in particulate form or in turn
may be subjected to further process steps of spraying liquids and coating with fine
powders.
[0074] While the performance of the particles described in the present invention remains
excellent, independently of the rest of the product matrix, it is advantageous to
finish the granular detergent composition in a way that maximises performance and
permits high flexibility to the formulation of a wide variety of products without
major process changes. This can be achieved by taking a modular approach to the building
of the finished product matrix.
[0075] The modular approach is based on the manufacturing of particles highly specific in
one or at most two ingredients of the formulation which are then mixed at the desired
ratios to form the finished products. These particles, being highly specific in the
ingredient they are to deliver, can be used in a wide range of products without need
to be modified. These particles can be prepared with an optimal combination of ingredients
that maximize their properties independently of full finished product formulations.
[0076] In particular, the nonionic surfactant particles described in the present invention,
can be suitably complemented with one high activity anionic surfactant particle and
at least one builder particle.
The ability to manufacture high activity nonionic and anionic particles separately
allows their use at different ratios in different formulations. The high activity
of these particles allow their preparation with a minimum amount of process aids,
which are typically inorganic builders such as zeolites, carbonates, silicates, etc.
Therefore, in a typical household granular detergent composition, there is room to
be able to incorporate one or more highly specific builder particles by dry mixing.
The presence of builder particles that dissolve independently from the surfactants,
and which preferably have a more rapid rate of solution than the principle particles
which contain the surfactants, is preferred. This improves the rate of alkalinity
release to the wash and reduces the potential precipitation of the surfactants with
salts of calcium or magnesium present in hard water.
Processing
[0077] The nonionic surfactant containing particles of the present invention may be prepared
by:
a) pumping a surfactant system in its low viscosity state;
b) cooling said nonionic surfactant to a temperature where its viscosity is increased
to at least 20000 cps;
c) granulating the surfactant in the presence of a finely divided powder;
d) cooling said agglomerates.
[0078] Each of these process steps will now be described in more detail.
[0079] The surfactant system may be pumped using any conventional pumping means. However
one preferred means of pumping is to use an extruder. The extruder fulfils the functions
of pumping and mixing the surfactant system on a continuous basis. A basic extruder
consists of a barrel with a smooth inner cylindrical surface. Mounted within this
barrel is the extruder screw. There is an inlet port for the surfactant system which,
when the screw is rotated, causes the surfactant system to be moved along the length
of the barrel.
The detailed design of the extruder allows various functions to be carried out. Additional
ports in the barrel may allow other ingredients, including co-surfactants and/or chemical
structuring agents to be added directly into the barrel. Secondly means for heating
or cooling may be installed in the wall of the barrel for temperature control. Thirdly,
careful design of the extruder screw promotes mixing of the paste both with itself
and with other additives.
A preferred extruder is the twin screw extruder. This type of extruder has two screws
mounted in parallel within the same barrel, which are made to rotate either in the
same direction (co-rotation) or in opposite directions (counter-rotation). The co-rotating
twin screw extruder is the most preferred piece of equipment for use in this invention.
An extruder is particularly useful in this invention because the paste can be effectively
cooled by adding liquid nitrogen or solid carbon dioxide into the barrel and at the
same time pumps the increasingly viscous (colder) paste out of the extruder.
Suitable twin screw extruders for use in the present invention include those supplied
by : APV Baker, (CP series); Werner and Pfleiderer, (Continua Series); Wenger, (TF
Series); Leistritz, (ZSE Series); and Buss, (LR Series).
[0080] The surfactant system is transferred from the pumping means into a cooling means.
The means for cooling may be any type of conventional heat exchanger. The surfactant
system is introduced into the heat exchanger at a temperature above its softening
point, and then cooled to a temperature close to, or even below its softening point
with a resulting sharp increase in viscosity.
The cooling step (b) is preferably performed using a high pressure scraped surface
heat exchanger. Such a piece of equipment is the Chemetator (Trade Name), manufactured
by Crown Chemtech Ltd., Reading, England; and the Fryma (Trade Name), manufactured
by Fryma Maschinen AG, Reinfelden, Switzerland.
If a very short residence time is achieved in the heat exchanger (less than 60 seconds,
preferably less than 30 seconds), shock cooling or supercooling can be achieved. In
this way the paste stays in a liquid form even at temperatures below its softening
point for a short period of time. The allows very high active agglomerates to be produced.
[0081] The viscous surfactant system is then granulated with suitable powders (step (c)).
Many processes for granulating surfactant pastes are known to the man skilled in the
art. A process which is suited to the present invention is that of fine dispersion
mixing or agglomeration. In this process a finely dispersed viscous surfactant system
is contacted with a finely divided powder which causes the powder to stick together
(or agglomerate). Normally a blend of powders is present in the granulation step,
in which case not all of the powders need to be finely divided. The result is a granular
composition which generally has a particle size distribution in the range of 250 to
1200 micrometers and has a bulk density of at least 650 g/l. In the present invention
the viscous surfactant system is used as the paste which is finely dispersed with
an effective amount of powder in a suitable mixer. Suitable mixers for carrying out
the fine dispersion mixing are described in more detail below. Any suitable powder
may be chosen by mixing one or more of the ingredients listed above which may be conveniently
handled in powder form. Powders comprising zeolite, carbonate, silica, silicate,sulphate,
phosphate, citrate, citric acid and mixtures of these are particularly preferred.
The transfer of the viscous surfactant system from the heat exchanger into the
mixer can be done in many ways, from simply pouring to high pressure pumping through
small holes at the end of the pipe, before the entrance to the mixer. While all these
ways are viable to manufacture agglomerates with good physical properties, it has
been found that in a preferred embodiment of the present invention the extrusion of
the paste through a die results in a better distribution in the mixer which improves
the yield of particles with the desired size.
[0082] Preferred operating temperatures should also be as low as possible since this leads
to a higher surfactant concentration in the finished particle. Preferably the temperature
during the agglomeration is less than 80°C, more preferably between 0°C and 70°C,
even more preferably between 10 and 60°C and most preferably between 20 and 50°C.
Lower operating temperatures useful in the process of the present invention may be
achieved by a variety of methods known in the art such as nitrogen cooling, cold water
jacketing of the equipment, addition of solid CO2, and the like; with a preferred
method being solid CO2, and a most preferred method being nitrogen cooling.
[0083] Suitable pieces of equipment in which to carry out the fine dispersion mixing or
granulation of the present invention are mixers of the Fukae
R FS-G series manufactured by Fukae Powtech Kogyo Co., Japan; this apparatus is essentially
in the form of a bowl-shaped vessel accessible via a top port, provided near its base
with a stirrer having a substantially vertical axis, and a cutter positioned on a
side wall. The stirrer and cutter may be operated independently of one another and
at separately variable speeds. The vessel can be fitted with a cooling jacket or,
if necessary, a cryogenic unit.
Other similar mixers found to be suitable for use in the process of the invention
include Diosna
R V series ex Dierks & Söhne, Germany; and the Pharma Matrix
R ex T K Fielder Ltd., England. Other mixers believed to be suitable for use in the
process of the invention are the Fuji
R VG-C series ex Fuji Sangyo Co., Japan; and the Roto
R ex Zanchetta & Co srl, Italy.
Other preferred suitable equipment can include Eirich
R, series RV, manufactured by Gustau Eirich Hardheim, Germany; Lödige
R, series FM for batch mixing, series Baud KM for continuous mixing/agglomeration,
manufactured by Lödige Machinenbau GmbH, Paderborn Germany; Drais
R T160 series, manufactured by Drais Werke GmbH, Mannheim Germany; and Winkworth
R RT 25 series, manufactured by Winkworth Machinery Ltd., Berkshire, England.
The Littleford Mixer, Model #FM-130-D-12, with internal chopping blades and the
Cuisinart Food Processor, Model #DCX-Plus, with 7.75 inch (19.7 cm) blades are two
examples of suitable mixers. Any other mixer with fine dispersion mixing and granulation
capability and having a residence time in the order of 0.1 to 10 minutes can be used.
The "turbine-type" impeller mixer, having several blades on an axis of rotation, is
preferred. The invention can be practiced as a batch or a continuous process.
[0084] The granulated surfactant particles are then allowed to cool to ambient temperatures.
This may be most effectively achieved in a fluid bed cooler.
Further Processing Steps
[0085] The granular components or compositions described above may be suitable for use directly,
or they may be treated by additional process steps. Commonly used process steps include
drying, cooling and/or dusting the granules with a finely divided flow aid. In addition
the granules may be blended with other components in order to provide a composition
suitable for the desired end use as has been described above.
Any type of mixer or dryer (such as fluid bed dryers) may be found to be suitable
for this purpose.
The finely divided flow aid, if used, may be chosen from a wide variety of suitable
ingredients such as zeolite, silica, talc, clay or mixtures of these.
Examples
[0086] In the following examples the abbreviation :
C25E3 stands for a C12-C15 primary alcohol condensed with an average of 3 moles of
ethylene oxide;
C28AS stands for alkyl sulphate with a carbon chain length principally from C12 to
C18. PEG4000 stands for polyethylene glycol having an average molecular weight of
4000.
Example 1
[0087] High active nonionic surfactant particulate compositions were prepared in batch mode
using a pilot plant scale high shear mixer, an Eirich RVO2. The mixer was first charged
with a mixture of powders, namely, Zeolite A , Alkyl Sulphate powder (having a carbon
chain length distribution of C12 to C18), finely divided sodium carbonate and PEG4000.
A surfactant system in the form of a nonionic surfactant paste consisting of a homogeneous
mixture of 1 part ethoxylated nonionic surfactant and 1 part polyhydroxy fatty acid
amide (Palm Glucosamide), was then added on top of the powder mixture while the mixer
was being operated at 1600rpm. Paste was added until discrete granules were formed
in the mixer. The agglomerates where then transferred to a rotating drum mixer and
dusted for 1-2 minutes with a flow aid at a level of 3 % by weight of the granular
detergent. The flow aid was a blend of 30 parts zeolite with 1 part hydrophobic silica.
The compositions of the agglomerates are given below in Table 1.
Table 1
| |
Composition 1A % by weight |
Composition 1B % by weight |
| Polyhydroxy fatty acid amide |
18 |
19 |
| Nonionic surfactant (C25E3) |
18 |
19 |
| Sodium Alkyl Sulphate |
18 |
20 |
| Sodium Carbonate |
27 |
21 |
| Zeolite |
8 |
18 |
| Poly ethylene glycol (MW=4000) |
8 |
|
| Flow aid (Zeolite/Hydrophobic silica) |
3 |
3 |
[0088] The resulting agglomerates were made with a total surfactant activity of 54% and
58% respectively and showed good cake strength and compression values, and dissolved
rapidly in water.
Example 2
[0089] The process of example 1 was repeated to provide the following composition (see table
2):
Table 2
| |
% by weight |
| Polyhydroxy fatty acid amide |
20 |
| Nonionic surfactant (C25E3) |
20 |
| Sodium Carbonate |
30 |
| Zeolite |
27 |
| Flow aid (Zeolite/Hydrophobic silica) |
3 |
[0090] The resulting agglomerates were made with a total surfactant activity of 40% and
showed good cake strength and compression value. Although the rate of dissolution
in water was still acceptable, it was not as rapid as the composition of example 1
under comparable conditions.
Comparative example 3
[0091] This example describes the process in batch mode in a pilot plant scale high shear
mixer as used in example 1. The mixer was first charged with a mixture of powders
namely Zeolite A and finely divided sodium carbonate. A surfactant system in the form
of a nonionic surfactant paste consisting of a homogeneous mixture of 1 part ethoxylated
nonionic surfactant and 3 parts of polyhydroxy fatty acid amides (Tallow Glucosamide),
was then added on top of the powder mixture while the mixer was being operated at
1600rpm.The following composition was made (see table 3):
The surfactant system has a high softening point, greater than 100°C.
Table 3
| |
% by weight |
| Polyhydroxy fatty acid amide |
30 |
| Nonionic surfactant (C25E3) |
10 |
| Sodium Carbonate |
30 |
| Zeolite |
27 |
| Flow aid (Zeolite/Hydrophobic silica) |
3 |
[0092] The resulting agglomerates were made with a total surfactant activity of 40% and
showed good cake strength and compression values. However the rate of dissolution
of this composition was considerably slower than either of examples 1 or 2.
Comparative example 4
[0093] This example describes the process in batch mode in a pilot plant scale high shear
mixer as used in example 1. The mixer was first charged with a mixture of powders
to be used, namely Zeolite A and finely divided sodium carbonate. A surfactant system
in the form of a nonionic surfactant paste consisting of a homogeneous mixture of
3 parts ethoxylated nonionic surfactant and 1 part polyhydroxy fatty acid amides (Tallow
Glucosamide), was then added on top of the powder mixture while the mixer was being
operated at 1600rpm. The surfactant system had a softening point of 40°C and a viscosity
of only 13000 cps at a temperature just above that softening point (viscosity measured
at a shear rate of 25s⁻¹). The following composition was made (see table 4):
Table 4
| |
% by weight |
| Polyhydroxy fatty acid amide |
7 |
| Nonionic surfactant (C25E3) |
21 |
| Sodium Carbonate |
35 |
| Zeolite |
34 |
| Flow aid (Zeolite/Hydrophobic silica) |
3 |
[0094] The resulting agglomerates were made with a total surfactant activity of 28% and
showed higher cake strength and compression values. Although this composition has
a rapid rate of dissolution, the total surfactant activity achieved is lower than
either of examples 1 or 2.
Comparative example 5
[0095] This example describes the process in batch mode in a pilot plant scale high shear
mixer as used in example 1. The mixer was first filled with a mixture of powders to
be used, in this particular case Zeolite A and fine sodium carbonate. A nonionic surfactant
paste of polyhydroxy fatty acid amides (Tallow Glucosamide) with a softening point
of 148°C (in this case the softening point is a true melting point), was then added
on top of the powder mixture while the mixer was being operated at 1600rpm.The following
composition was made (see table 5):
Table 5
| |
% by weight |
| Polyhydroxy fatty acid amide |
40 |
| Sodium Carbonate |
30 |
| Zeolite |
27 |
| Flow aid (Zeolite/Hydrophobic silica) |
3 |
[0096] The resulting agglomerates were made with a total surfactant activity of 40% and
showed high cake strength and compression values. However the rate of dissolution
of this composition was considerably slower than either of examples 1 or 2.
Example 6
[0097] This example describes the process in batch mode in a pilot plant scale high shear
mixer as used in example 1. The mixer was first charged with a mixture of powders
to be used, namely Zeolite A, finely divided citrate and finely divided sodium carbonate.
Anionic surfactant agglomerates were separately prepared by granulating a 78% active
surfactant paste (4 parts alkyl sulphate, C14-C15 and 1 part alkyl ether sulphate,
C13-C15 with an average of 3 ether groups per molecule) with a powder mixture of zeolite,
carbonate, CMC, acrylic-maleic co-polymer. 22 parts of surfactant paste, 11 parts
of zeolite, 9 parts of carbonate, 1 part of CMC and 5 parts of co-polymer were used
and the resulting agglomerates were ground and sieved through mesh 250 microns. These
fine anionic surfactant agglomerates were then added together with a surfactant system
in the form of nonionic surfactant paste on top of the powder mixture while the mixer
was operating at 1600rpm. The nonionic surfactant paste consisting of 1 part ethoxylated
nonionic surfactant and 1 part polyhydroxy fatty acid amides (Palm Stearine Glucosamide).
The nonionic surfactant paste was cooled from 70 to 55 °C and extruded from a high
pressure scraped surface heat exchanger. The following composition was made (see table
6):
Table 6
| |
% by weight |
| Polyhydroxy fatty acid amide |
19 |
| Nonionic surfactant (C25E3) |
19 |
| Sodium Carbonate |
13 |
| Zeolite |
13 |
| Citrate |
13 |
| Fine anionic agglomerates |
20 |
| Flow aid (Zeolite/Hydrophobic silica) |
3 |
[0098] The agglomerates show excellent handling properties and rate of surfactant release.
Example 7
[0099] A surfactant system was prepared by thorough mixing of two nonionic surfactants;
namely, 50% by weight palm stearine (C16-C18) glucosamide (GA) with 50% by weight
of C12-C15 alkyl ether sulphate (having an average of 3 ether groups per mole), C25E3.
[0100] The surfactant system had a softening point at 50°C, and viscosities of 25000 cps
at 60°C, and 100 cps at 70°C.
[0101] The surfactant system was cooled from 70°C to 60°C and then granulated with a mixture
of particulate materials to give the following composition:
| |
% by weight |
| Nonionic surfactant (GA/C25E3) |
40 |
| C12-C28 alkyl sulphate powder |
10 |
| Zeolite A |
20 |
| Citrate |
20 |
| Polyethylene glycol (MW=4000) |
5 |
| Water and miscellaneous |
5 |
Example 8
[0102] Example 7 was repeated replacing the palm stearine glucosamide by tallow stearine
glucosamide.
[0103] The surfactant system had a softening point at 65°C, and viscosities of 25000 cps
at 75°C, and 100 cps at 85°C.
[0104] The surfactant system was cooled from 85°C to 45°C using a high pressure scraped
surface heat exchanger. The short residence time (10 seconds) in the heat exchanger
results in the surfactant system remaining liquid for a short period of time even
below the solidification point. Granulation was then carried out with a mixture of
particulate materials in a Braun food processor to give the following compositions:
| |
Ex. 8A % by weight |
Ex. 8B % by weight |
| Nonionic surfactant (GA/C25E3) |
50 |
50 |
| C12-C28 alkyl sulphate powder |
- |
15 |
| Zeolite A |
25 |
20 |
| Carbonate |
25 |
15 |
Example 9
[0105] The process of example 8 was repeated using a die at he outlet of the heat exchanger
to form noodles or extrudates of the surfactant system. The following composition
was produced:
| |
% by weight |
| Nonionic surfactant (GA/C25E3) |
60 |
| C12-C28 alkyl sulphate powder |
20 |
| Zeolite A |
10 |
| Carbonate |
10 |
[0106] The compositions of examples 7 to 9 showed good cake strength and compression values,
and dissolved rapidly in water.
Example 10
[0107] High active nonionic surfactant particulate compositions were prepared in a batch
mode using a pilot plant scale mixer, an Eirich RVO2. The mixer was charged with a
mixture of powders, namely zeolite A , Alkyl Sulphate powder, and finely divided sodium
carbonate. Molten dodecyl glycerol ether was added on top of the powder while the
mixer was being operated at 1200 rpm. The nonionic surfactant was added until discrete
granules were formed. This viscosity of the dodecyl glycerol ether was 20,000 cps
at 60°C but 4000 cps at 80°C.
[0108] The composition was:
| |
% by weight |
| Dodecyl Glycerol Ether |
40% |
| Alkyl Sulphate |
10% |
| Sodium Carbonate |
25% |
| Zeolite |
25% |
[0109] The agglomerates had a total surfactant activity of 50 % and showed good cake strength
and compression values.
Example 11
[0110] A finished laundry detergent was put together by blending the following components:
| |
% by weight |
| a) Nonionic surfactant agglomerate |
13.4 |
| b) Anionic surfactant agglomerate |
32.5 |
| c) Layered Silicate compacted granule |
10.1 |
| d) Granular Percarbonate |
22.7 |
| e) Teatraacetylethylene diamine agglomerate |
7.8 |
| f) Suds Suppressor Agglomerate |
6.5 |
| g) Perfume encapsulate |
0.1 |
| h) Granular Soil Release Polymer |
0.4 |
| i) Granular Sodium Citrate dihydrate |
3.5 |
| j) Enzymes |
3.0 |
[0111] Component a) was prepared according to the composition and process described in Example
1A above.
[0112] Component b) was prepared from an anionic surfactant paste having the following composition,
the separate ingredients being mixed in aqueous form and subsequently dried to the
required water level:
| alkyl sulphate (C14-C15) |
57.2 |
| alkyl ether sulphate (C13-C15 with 3EO) |
14.3 |
| acrylic-maleic copolymer |
16 |
| sodium ethylenediamine-N,N'-disuccinic acid |
1.5 |
| water |
11 |
[0113] The anionic surfactant paste was maintained at 60°C and added to an Eirich RV02 mixer,
operating at 1600 rpm with the following powder composition:
| zeolite A |
14 |
| light soda ash |
75 |
| Carboxymethyl cellulose |
4 |
| Magnesium sulphate |
4 |
| Water |
3 |
[0114] Sufficient surfactant paste was added to the mixer until discrete particles, having
an average particle size of about 500 micrometers were obtained. The particles were
then dried in a fluid bed dryer to an equilibrium relative humidity of 10% at 20°C.
[0115] The final particulate composition of component b) contained 53% anionic surfactant
and had a bulk density of 710 g/l.
[0116] Component c), the layered silicate compact granule, was prepared from powder layered
silicate 2.0 ratio (SKS-6 trade name ex Hoechst), powder citric acid and ethoxylated
tallow alcohol, TAE50 (average of 50 ether groups). The SKS-6 and the citric acid,
both with an average particle size of about 150 microns were mixed together while
sprayed with TAE50 in a rotating spray drum at the following composition :
77% SKS-6
21% anhydrous citric acid
2% TAE50
The mixture was then passed to the feed hopper of a roll compactor and was compacted
into a flake. The flake was ground up to 600 microns average particle size. The oversize
fraction was recycled back to the grinder and the fines fraction back to the compactor.
[0117] The particle prepared via this process reaches its maximum calcium exchange capacity
at the pH of the wash in less than 2 minutes.
[0118] Components d) to j) were obtained from the following commercially available sources:
d) supplied by Interox; e) supplied by Warwick International; f) prepared according
to US3,933,672; g) supplied by Haarman & Reimer; h) supplied by Hoechst; i) supplied
by Jungbunzlauer; j) supplied by Novo Nordisk.
[0119] The finished composition was made by placing components a) to j) in a 120 litre rotating
drum operating at 15 rpm. A mixture of nonionic surfactant and a 20% aqueous solution
of optical brightener at ratios of 14:1 were sprayed at 55°C on to the granular mixture
to a level of 5% by weight of the finished product. The nonionic surfactant used consisted
of a mixture of 7 parts of nonionic surfactant (C25E3) with 3 parts of palm stearine
glucosamide.
[0120] Immediately afterwards, perfume was sprayed on at a level of 0.5%. Finally, without
stopping the rotating drum, zeolite was slowly added to the drum to a level of 5%
by weight of the finished product. The mixer was then continued for a further 30 seconds,
and the product then discharged.
[0121] After two days of ageing the finished composition had a bulk density of 850 g/l.
The particle size distribution was:
| Tyler Sieve no. |
Micrometers |
% by weight of product on sieve |
| 14 |
1180 |
17 |
| 20 |
850 |
39 |
| 35 |
425 |
88 |
| 65 |
212 |
99 |
| 100 |
150 |
99.5 |
[0122] The mean particle size of the finished product composition was about 720 micrometers.
[0123] The product prepared according to this example exhibits very high rates of dissolution
of both anionic and nonionic surfactants. Furthermore the rate of alkalinity release
(principally due to component c) was excellent.
Example 12
[0124] A homogeneous mixture of 2 parts polyhydroxy fatty acid amide (Palm Stearine Glucosamide)
with 3 parts ethoxylated nonionic surfactant (C25E5) at 85°C was mixed with a copolymer
of acrylic-maleic acid. The paste was then cooled from 85 to 45 °C using a high pressure
scraped surface heat exchanger. The viscosity of the cooled paste was greater than
20 000 cps. The cooled paste was immediately agglomerated with detergent powders in
a Braun food processor. In this example the powders were alkyl sulphate, sodium carbonate
and zeolite A. The resulting agglomerates had the following composition:
| |
% by weight |
| Polyhydroxy fatty acid amide |
16 |
| Nonionic surfactant |
24 |
| Zeolite A (hydrated) |
20 |
| Carbonate |
15 |
| Sodium alkyl sulphate |
15 |
| Copolymer of acrylic-maleic acid |
10 |
[0125] The composition shows good cake strength and compression values and a high rate of
surfactant release in water.
Example 13
[0126] This example describes the same process as used in example 12 but now some of the
alkyl sulphate powder was premixed with the mixture of nonionic surfactants prior
to cooling. A die was used at the outlet of the heat exchanger and therefore the paste
was coming out as noodles or extrudates. The cooled paste was immediately agglomerated
with detergent powders including a copolymer of acrylicmaleic acid in a Braun food
processor. In this case the powders are Alkyl sulphate (C28AS), sodium carbonate and
zeolite A.
| |
% by weight |
| Polyhydroxy fatty acid amide |
20 |
| Nonionic surfactant |
30 |
| Alkyl Sulphate |
20 |
| Zeolite A (hydrated) |
10 |
| Carbonate |
10 |
| Copolymer of acrylic-maleic acid |
10 |
Example 14
[0127] This example describes the same process as used in example 13 but a cooled twin screw
extruder was used to premix the alkyl sulphate with the nonionic surfactant instead
of a scraped surface heat exchanger.
Example 15
[0128] This example describes the process in batch mode in a pilot plant scale high shear
mixer, an Eirich RVO2, to produce high active nonionic detergent agglomerates. The
mixer was first charged with a mixture of powders to be used, in this example Zeolite
A , Alkyl Sulphate (C28AS), fine citrate and fine sodium carbonate. A nonionic surfactant
paste comprising a mixture of 1 part polyhydroxy fatty acid amides (Palm Stearine
Glucosamide) with 2 parts ethoxylated nonionic surfactant (C25E5) was mixed with polyethyleneoxide
(molecular weight = 100 000). The paste was then added to the high shear mixer containing
the powder mixture while the mixer was being operated at 1600rpm. Enough paste was
added until the granulation was achieved. The agglomerates were then transferred to
a rotating drum mixer and dusted for 1-2 minutes with a flow aid at a level of 3 %
by weight of the granular detergent. The composition of the agglomerates is given
below.
| |
% by weight |
| Polyhydroxy fatty acid amide |
12 |
| Nonionic surfactant (C25E5) |
24 |
| Alkyl Sulphate |
20 |
| Sodium Carbonate |
14 |
| Zeolite A |
10 |
| Fine citrate |
10 |
| Polyethyleneoxide |
7 |
| Flow aid (ZeoliteA /Zeolite DAY) |
3 |
[0129] The resulting agglomerates were made with a total surfactant activity of 57 % and
showed good cake strength and compression values. The rate of nonionic surfactant
release in water is comparable to example 12.
Example 16
[0130] A homogeneous mixture of 1 part Palm Stearine Glucosamide with 1 part ethoxylated
nonionic surfactant (C25E5) at 90°C was mixed with a molten Palmitic Acid, PEG 4000
and zeolite in a jacketed tank fitted with a mixing screw. The resultant mixture was
fed into a continuous belt cooler and produced into flakes. The flakes had the following
composition:
| |
% by weight |
| Polyhydroxy fatty acid amide |
20 |
| Nonionic surfactant |
20 |
| Palmitic Acid |
10 |
| Zeolite |
30 |
| PEG 4000 |
10 |
| Alkyl Sulphate |
10 |
[0131] The resulting flakes were ground up to average particle size of 200 microns in a
pin disk mill using 5 % zeoliteA as a flow aid. The resulting powders showed good
cake strength and compression values. The rate of nonionic surfactant release in water
is comparable to example 12.
Example 17
[0132] A homogeneous mixture of 3 parts Palm stearine Glucoseamide and 7 parts ethoxylated
nonionic surfactant (C25E5) was cooled in a Scraped Wall Cooler (Chemitator®) to 45°C
and mixed with powdered Alkyl Polyglucoside in a twin screw extruder. The resulting
mixture had a viscosity of greater than 20.000 cps. The mixture was the agglomerated
in batch mode in a pilot plant scale high shear mixer, an Eirich RVO2. The mixer was
first charged with a mixture of powders to be used, in this particular case Zeolite
P, fine citrate and water as a binder, and then the surfactant mixture was added to
the mixture to produce nonionic detergent agglomerates.
| |
% by weight |
| Polyhydroxy fatty acid amide |
10 |
| Nonionic surfactant |
23 |
| APG |
12 |
| Zeolite P |
25 |
| Citrate |
25 |
| moisture |
5 |
[0133] The resulting agglomerates were made with a total detergent activity of 45% and showed
good cake strength and compression values. The rate of nonionic surfactant release
in water is comparable to example 12.