Note: Descriptions are shown in the official language in which they were submitted.
JVO 95/13358 PCTIGB94I02458
- 1 -
PROCF~~ FnR muF pR~nrTC~mrnN nF A DETERGENT COMPOSITION
This invention relates to a process for the production of a
detergent composition. In particular this invention relates
to a process for the production of a high bulk density
detergent composition containing a fluorescer.
Detergent powders typically include components in addition to
the detergent-active materials necessary for detergency which
provide the powder with characteristics which may be viewed
as desirable by the market for example perfume'and
fluorescer. Fluorescers have been used for many years in
conventional spray-dried powders to give improved whiteners.
In the production of spray-dried powders, the fluorescer
material is typically incorporated into the slurry of
components which is to be spray-dried to produce the powder.
With the advent of high bulk density powders, for example
having a bulk density in excess of 750g/1, new process routes
have been proposed which involve subjecting a spray-dried
powder to a "post-tower" mixing and densification process or
mixing anti densifying the components of the detergent
composition without the use of a spray-drying step ("non-
tower" process) for example as described in EP-A-367339
(Unilever).
Production of a detergent composition by a mixing process
typically involves contacting and mixing the liquid
components with the solid components of the composition so
that the liquid binds the solid material thereby to form
composition particles. With further mixing the particles
increase in size to form granules. The ratio of liquids to
WO 95113358 PGT/GB94J02458
-2- 2173445
solids has to be sufficiently high to promote binding but not
so high that discrete particles are not obtained.
In "non-tower" processes fluorescers have been incorporated
into the powder as a solid material in the
mixing/densification step. However fluorescers may have an
undesirable colour. Incorporating such fluorescers in solid
form may impair the colour quality of the final powder.
We have now found that high bulk density powders having
excellent colour properties may be produced by incorporating
a fluorescer into a liquid component of the detergent
composition to produce a pre-mix of the fluorescer which is
then combined with solid components in a mixing step to
produce the particulate composition.
According to the invention there is provided a process for the production of a
high bulk density particulate detergent composition or component thereof
2 0 containing a fluorescer, which comprises mixing the fluorescer with a
liquid
component of the composition or component, said liquid component consisting
essentially of a nonionic surfactant and water and/or fatty acid, to form a
fluorescer mixture, and mixing the said fluorescer mixture with a solid
2 5 component of the composition or component whereby a particulate detergent
composition or component is produced.
High bulk density compositions having a bulk density of at
least 750g/1 may be produced by the present invention. The
30 process of the present invention may be a continuous or a
batch process as desired.
The components of the detergent composition will be selected
to provide the desired characteristics and will generally
35 include a surfactant and a builder in addition to the
fluorescer.
,...,..y.~
h
WO 95/13358 2 1 7 3 4 4 5 PCT/GB94/02458
- 3 -
The composition comprises at least one liquid component in
order to bind the solid components together. The fluoresces
is mixed with a liquid component, to form a fluoresces
mixture which maybe a slurzy, dispersion or suspension.
Agitation may be necessary in such cases to avoid undesirable
sedimentation. It is especially preferred that the
fluoresces mixture is a solution as particularly good powder
colour may be secured.
It is preferred that the fluoresces mixture comprises a liquid nonionic
surfactant.
Further, the fluoresces mixture more preferably comprises a mixture of a
fluoresces, a nonionic surfactant and water and optionally a fatty acid.
Suitable nonionic surfactants have an average degree of
alkoxylation of 3 or more, preferably 5 or more, and
desirably 20 or less. Desirably the fluoresces mixture is a
solution to facilitate homogeneous dispersion of the
fluoresced through the composition and the nonionic suitably
has an average degree of alkoxylation of 6 or more.
Ethoxylated alcohols are especially preferred. Suitable
examples include SYNPERONICTM A3, SYNPERONICTM A7 ex ICI and
coconut oil ethoxylates having an average degree of
ethoxylation of 6.5. Examples of other liquid components
which may be employed with the nonionic surfactant include
polyethylene glycols, for example PEG 1500, and glycerol.
The fluoresces may comprise a fluoresces known in the art,
such as a biphenyl compound for example a distryl biphenyl
compound. An especially preferred fluoresces is TINOPALTM CBS-
WO 95/13358 PCTlGB94/02458
- 4 -
X ex Ciba Geigy. The fluorescer is suitably present in the
composition in an amount of 0.001 to lo, preferably 0.005 to
0.5%, more preferably O.Olo to 0.40, especially 0.01 to 0.250
by weight based on the total composition.
The liquid component and fluorescer are suitably present in
the fluorescer mixture in a ratio of 10:0.01 to 5 by weight
preferably 10: 0.06 to 4 and more preferably 10:0.1 to 4. An
especially preferred fluorescer mixture comprises a nonionic
surfactant, for example SYNPERONIC A7 ex ICI, water and a
fluorescer, for example TINOPAL CBS-X. Suitably the nonionic
surfactant and water are present in a weight ratio of 50:1 to
1:10, preferably 20:1 to 3:8 and more preferably 10:1 to 3:8.
Superior powder whiteness (lower 'b' value) is obtained at
higher levels of nonionic in the fluoroescer mixture. The
fluorescer suitably represents 1 to 250, preferably 5 to 150
and more preferably 6 to 12o by weight of the fluorescer
mixture.
Higher levels of fluorescer may be employed to provide fabric
whitening benefits but this advantage may be offset by a
poorer powder colour at high levels of fluorescer where the
fluorescer is coloured, for example, in excess of 0.5o by
weight ba~ed on the total powder.
Suitably, other fluorescers are included in the composition
to improve fabric whiteness, thus obviating the need for
undesirably high levels of coloured fluorescer, for example
TINOPAL CBS-X. Preferably a dimorpholino fluorescer is
present in the composition together with the powder
fluorescer.
The fluorescer mixture water is suitably prepared by mixing
the fluorescer with the liquid oomponent with agitation to
obtain preferably a solution. For nonionic/water/fluorescer
.VO 95/13358 PCT/GB94102458
- 5 -
systems it is preferred that the fluoresces is mixed with the
nonionic surfactant and the water is then added subsequently,
or the fluoresces is added to a mixture of nonionic and
water. Preferably the fluoresces mixture is prepared such
that sedimentation of the fluoresces and 'gelling' of the
liquid at ambient temperature is avoided.
The solid component may comprise all of the components of the
detergent composition excluding the fluoresces mixture or
alternatively the solid component may comprise at least one
of the said components and the other components may be
incorporated into the composition during or subsequent to the
mixing of the solid component and the fluoresces mixture.
The solid component of the composition may comprise solid
particles of individual components or solid particles
comprising a plurality of components hereinafter referred to
as "adjuncts". Components of the detergent composition which
are liquid (excluding the fluoresces mixture? may be added to
the solid component during or subsequent to the mixing step
or incorporated by means of an adjunct as desired.
The solid component may be spray-dried powder but preferably
comprises'materials which are not produced directly by spray-
drying, especially if a high bulk density is required.
Accordingly, a second aspect of the invention provides a
process for the production of a detergent composition or
component containing a fluoresces which comprises mixing the
fluoresces with a liquid component to form a fluoresces
mixture, and mixing the said mixture.with a solid component
which is not the product of a spray-drying process, whereby a
particulate detergent composition is produced.
"''O 95/13358 ' 'L 1 7 3 4 4 5 p~~GB94102458
- 6 -
Preferably the mixing of the fluorescer mixture and the non-
spray-dried solid is effected in a high speed mixer with the
fluorescer mixture being sprayed onto the solid. The
particles obtained may be treated further as desired.
Optionally the particles may be passed directly to a cooling
and/or drying step to produce finished base powder particles,
to which other ingredients may then be post-mixed.
Alternatively, the particles may be passed to a second,
preferably low speed, mixing step in order to increase the
bulk density of the particles and optionally then cooled and/
or dried as desired.
Where a continuous process is employed, the mixing and
densification steps may be carried out simultaneously using a
high speed mixer, suitable examples include a Shugi
(trademark) Granulator, a Drais (trade mark) K-TTP 80
Granulator and the Lodige (trade mark) CB30 recycler. The
residence time in the mixing step is suitably about 5 to 30
seconds and the rate of mixing in the apparatus is suitably
in the range 100 to 2500rpm depending upon the degree of
densification and the particle size required. The granulation
step if present may be carried out using a lower speed mixex
for example, the Drais (trade mark) K-T 160 and the Lodige
(trade mark) KM300 mixer. The residence time in the
. granulation step is suitably about 1'to 10 minutes and the
rate of mixing in the apparatus is about 40 to 160 rpm.
A batch process may be employed in which the solid components
of the composition are dosed into a mixer and the fluorescer
mixture is suitably sprayed onto the .solid component.
Suitable mixers include the FUKAET"' range of mixers. Other
materials may be added subsequently as desired. Residence
time is selected according to tMe required degree of
granulation for example 1 to 20 minutes.
iV ~. ~ v a. .. -
JVO 95/13358 PCT/GB94/02458
The fluoresces mixture is preferably sprayed onto the solid
component of the composition to provide an even distribution
of the mixture over the solid component.
We have found that a high bulk density detergent compositions
having excellent colour properties may be secured by a
process according to the first or second aspect of the
invention.
A third aspect of the invention provides a detergent
composition comprising a fluoresces which composition is
obtainable by a process according to the first aspect of the
invention.
A fourth aspect of the invention provides a detergent
composition having a high bulk density and comprising a
surfactant, detergency builder and a fluoresces which has a
Delta 8460 value of at least 3.5, preferably at least 5.5 and
more preferably at least 6.5.
Preferably the fluoresces is incorporated into the
composition by a process according to the first or second
aspect of the invention.
Delta 8460 values are determined by measuring the reflectance
of light from the sample at 460 nm when eradiated with a
tungsten lamp without a filter and measuring the reflectance,
of the sample with a W filter and calculating the difference
between the two measurements. The sample analysed is a 355
to 500 um fraction obtained by sieving. This method provides
an indication of the contribution of the fluoresces to the
reflectance of the sample.
Compositions produced according~to the present invention will
generally contain detergent-active compounds and detergency
21'~3~~~
WO 95/13358 PCT/GB94102458
_ g _
builders, and may optionally contain bleaching components and
other active ingredients to enhance performance and
properties. The detergent-active compounds (surfactants) may
be chosen from soap and non-soap anionic, cationic, nonionic,
amphoteric and zwitterionic detergent-active compounds, and
mixtures thereof. Many suitable detergent-active compounds
are available and are fully described in the literature, for
example, in "Surface-Active Agents and Detergents", Volumes I
and II, by Schwartz, Perry and Berch.
The preferred detergent-active compounds that can be used are
soaps and synthetic non-soap anionic and nonionic compounds.
Anionic surfactants are well-known to those skilled in the
art. Examples include alkylbenzene sulphonates, particularly
linear alkylbenzene sulphonates having an alkyl chain length
of C8-C,S; primary and secondary alkyl sulphates,
particularly C12-C15 primary alkyl sulphates; alkyl ether
sulphates; olefin sulphonates; alkyl xylene sulphonates;
dialkyl sulphosuccinates; and fatty acid ester sulphonates.
Sodium salts are generally preferred.
Nonionic surfactants may be included in any adjuncts employed
in the cofiposition in addition to that which may be present
in the fluorescer mixture. Suitable nonionics include the
primary and secondary alcohol ethoxylates, especially the
C8-CZO aliphatic alcohols ethoxylated with an average of from
1 to 20 moles of ethylene oxide per mole of alcohol, and more
especially the Clo-Cls Primazy and secondary aliphatic
alcohols ethoxylated with an average of from 1 to 10 moles of
ethylene oxide per mole of alcohol. Non-ethoxylated nonionic
surfactants include alkylpolyglycosides also glycerol
monoethers, and polyhydroxyamides (glucamide).
dV0 95/13358 PCT/GB94/02458
- 9 -
The choice of detergent-active compound (surfactant), and the
amount present, will depend on the intended use of the
detergent composition. For example, for machine dishwashing
a relatively low level of a low-foaming nonionic surfactant
is generally preferred. In fabric washing compositions,
different surfactant systems may be chosen, as is well known
to the skilled formulator, for handwashing products and for
products intended for use in different types of washing
machine.
The total amount of surfactant present will also depend on
the intended end use and may be as low as 0.5 wto, for
example, in a machine dishwashing composition, or as high as
60 wto, for example, in a composition for washing fabrics by
hand. In compositions for machine washing of fabrics, an
amount of from 5 to 40 wt% is generally appropriate.
Detergent compositions suitable for use in most automatic
fabric washing machines generally contain anionic non-soap
surfactant, or nonionic surfactant, or combinations of the
two in any ratio, optionally together with soap.
The detergent compositions of the invention will generally
also contain one or more detergency builders. The total
amount of detergency builder in the compositions will
suitably range from 10 to 80 wt~, preferably from 15 to 60
wt~.
Inorganic builders that may be present include sodium
carbonate, if desired in combination with a crystallisation
seed for calcium carbonate, as disclosed in GB 1 437 950
(Unilever); crystalline and amorphous aluminosilicates, for
example, zeolites as disclosed in GB 1 473 201 (Henkel),
amorphous aluminosilicates as disclosed in GB 1 473 202
(Henkel) and mixed crystalline/amorphous aluminosilicates as
21'3445
WO 95/13358 PCTlGB94102458
- 10 -
disclosed in GB 1 470 250 (Procter & Gamble); and layered
silicates as disclosed in EP 164 514B (Hoechst). Inorganic
phosphate builders, for example, sodium orthophosphate,
pyrophosphate and tripolyphosphate, may also be present.
Zeolite builders may suitably be present in amounts of from
to 45 wt%, amounts of from 15 to 35 wto being especially
suitable for (machine) fabric washing compositions. The
zeolite used in most commercial particulate detergent
10 compositions is zeolite A. Advantageously, however, maximum
aluminium zeolite P (zeolite MAP) described and claimed in EP
384 070A (Unilever) may be used. Zeolite MAP is an alkali
metal aluminosilicate of the P type having a silicon to
aluminium ratio not exceeding 1.33, preferably not exceeding
1.15, and more preferably not exceeding 1.07.
Organic builders that may be present include polycarboxylate
polymers such as polyacrylates, acrylic/maleic copolymers,
and acrylic phosphinates; monomeric polycarboxylates such as
citrates, gluconates, oxydisuccinates, glycerol mono-, di-
and trisuccinates, carboxymethyloxysuccinates,
carboxymethyloxymalonates, dipicolinates,
hydroxyethyliminodiacetates, alkyl- and alkenylmalonates and
succinate~; and sulphonated fatty acid salts. This list is
not intended to be exhaustive.
Especially preferred organic builders are citrates,
nitrolotriacetic acid and oxydisuccinate and are suitably
used in amounts of from 5 to 30 wto, preferably from 10 to 25
wt%; and acrylic polymers, more especially acrylic/maleic
copolymers, suitably used in amounts of from 0.5 to 15 wto,
preferably from 1 to 10 wto.
Builders, both inorganic and organic, are preferably present
in alkali metal salt, especially sodium salt, form.
WO 95/13358 PCT/GB94/02458
- 11 -
Detergent compositions according to the invention may also
suitably contain a bleach system. Machine dishwashing
compositions may suitably contain a chlorine bleach system,
while fabric washing compositions may more desirably contain
peroxy bleach compounds, for example, inorganic persalts or
organic peroxyacids, capable of yielding hydrogen peroxide in
aqueous solution.
Suitable peroxy bleach compounds include organic peroxides
such as urea peroxide, and inorganic persalts such as the
alkali metal perborates, percarbonates, perphosphates,
persilicates and persulphates. Preferred inorganic persalts
are sodium perborate monohydrate and tetrahydrate, and sodium
percarbonate.
Especially preferred is sodium percarbonate having a
protective coating against destabilisation by moisture.
Sodium percarbonate having a protective coating comprising
sodium metaborate and sodium silicate is disclosed in
GB 2 123 044B (Kao).
The peroxy bleach compound is suitably present in an amount
of from 5 to 35 wto, preferably from 10 to 25 wto.
The peroxy bleach compound may be used in conjunction with a
bleach activator (bleach precursor) to improve bleaching
action at low wash temperatures. The bleach precursor is
suitably present in an amount of from 1 to 8 wt~, preferably
from 2 to 5 wt o .
Preferred bleach precursors are peroxycarboxylic acid
precursors, more especially peracetic acid precursors and
peroxybenzoic acid precursors; and peroxycarbonic acid
precursors. An especially preferred bleach precursor
PCT/GB94/02458
WO 95/13358 21'~ 3 4 4 5
- 12 -
suitable for use in the present invention is
N,N,N',N'-tetracetyl ethylenediamine (TAED).
The novel quaternary ammonium and phosphonium bleach
precursors disclosed in US 4 751 015 and US 4 818 426 (Lever
Brothers Company) and EP 402 971A (Unilever) are also of
great interest. Especially preferred are peroxycarbonic
acid precursors, in particular cholyl-4-sulphophenyl
carbonate. Also of interest are peroxybenzoic acid
precursors, in particular, N,N,N-trimethylammonium toluoyloxy
benzene sulphonate; and the cationic bleach precursors
disclosed in EP 284 292A and EP 303 520A (Kao).
A bleach stabiliser (heavy metal sequestrant) may also be
present. Suitable bleach stabilisers include
ethylenediamine tetraacetate (EDTA) and the polyphosphonates
such as bequest (Trade Mark), EDTMP.
An especially preferred bleach system comprises a peroxy
bleach compound (preferably sodium percarbonate optionally
together with a bleach activator), and a transition metal
bleach catalyst as described and claimed in EP 458 397A, EP
458 398A and EP 509 787A (Unilever).
The compositions of the invention may contain alkali metal,
preferably sodium, carbonate, in order to increase detergency
and ease processing. Sodium carbonate may suitably be
present in amounts ranging from 1 to 60 wt%, preferably from
2 to 40 wto. However, compositions containing little or no
sodium carbonate are also within the scope of the invention.
Powder flow may be improved by the incorporation of a small
amount of a powder structurant, for example, a fatty acid (or
fatty acid soap), a sugar, an acrylate or acrylate/maleate
polymer, or sodium silicate.
WO 95/13358 PCTIGB94/02458
- 13 -
One preferred powder structurant is fatty acid soap, suitably
present in an amount of from 1 to 5 wto.
Other materials that may be present in detergent compositions
of the invention include sodium silicate and sodium
metasilicate; antiredeposition agents such as cellulosic
polymers; inorganic salts such as sodium sulphate; lather
control agents or lather boosters as appropriate;
proteolytic and lipolytic enzymes; dyes; coloured speckles;
perfumes; foam controllers; and fabric softening compounds.
This list is not intended to be exhaustive.
The invention is illustrated by the following non-limiting
Examples. All figure s in the Examples are parts by weight
unless otherwise stated.
Examples 1 to 6
Six compositions were produced by mixing a fluorescer mixture
with the other composition components in a FUKAE FS-30 mixer
to produce a granular detergent composition. The fluorescer
mixture was varied for each Example as listed in Table 1 and
the other composition components were as listed below:
PCT/GB94102458
WO 95/13358 1 ~ 3 ~ 4 5
- 14 -
Na LAS 20
Sodium tripolyphosphate 25
Zeolite 4A 23
Sodium carbonate 19
10
The final composition had the following components:
EXAMPLE FLUORESCENT MIXTURE
1 0.02 TINOPAL CBS-X in 2 NI (suspension)
(0.18 TINOPAL CBS-X added to mixer as solid)
2 0.2 TINOPAL CBS-X in 2 NI (suspension)
3 0.5 NI:0.05 TINOPAL CBS-X:0.05 water (solution)
(1.5 NI) added to mixer as liquid)
4 1.0 NI:0.1 TINOPAL CBS-X:0.1 water (solution)
(1.0 NI added to mixer as liquid)
5 1.5 NI:0.15 TINOPAL CBS-X:0.15 water (solution)
(0.5 NI added to mixer as liquid)
6 2.0 NI:0.2 TINOPAL CBS-X:0.2 water solution
The noniofiic used was SYNPERONIC A7 ex ICI.
The fluorescer mixtures were produced by mixing the TINOPAL
CBS-X fluorescer and nonionic to form a suspension. Where
present, water was then added to this suspension. The
mixture was then stirred slowly (to avoid sedimentation) for
minutes and then allowed to stand for 1 hour.
The final product was sieved to provide a fraction having a
30 particle size of 355 to 500um. .The reflectance of this
fraction was measured at 460um under W light and W excluded
21?~~~5
WO 95/13358 PCT/GB94/02458
- 15 -
light from which the F value was calculated as described
herein. The results are shown in Table 2.
Comparative Example A
A composition not according to the invention having the same
components as listed for Examples 1 to 6 and solid fluoresces
(0.2 parts) and non-active solid surfactant (2 parts) was
produced by mixing under the same conditions as Examples 1 to
6.
The F value of this composition was calculated and the
results are shown in Table 2.
TABLE 2
EXAMPLE F VALUE
1 3.9
2 5.5
3 6.9
4 7.1
5 7.5
6 7.2
A 3.0
The above results demonstrate that by incorporating the
fluoresces by way of a fluoresces mixture which is then mixed
with the solid components, improved powder whiteness is
secured as compared with the process of the prior art.
Further, Examples 3 to 6 illustrate that further improved
whiteness is secured if the fluoresces mixture is a solution.
WO 95113358 PCTIGB94102458
- 16 -
Example 7 to 14
A series of powders were produced having a fixed level of
CBS-X fluorescer which was introduced as a fluorescer mixture
consisting of the fluorescer and varying ratios of SYNPERONIC
A7, nonionic surfactant and water. The compositions
contained the following components (parts by weight):
SODIUM CARBONATE 16
SODIUM TRIPOLYPHOSPHATE 40
ZEOLITE 4A 11
Na LAS 2~
TINOPAL CBS-X 0.2
SYNPERONIC A7 2
WATER 1'8
MINORS to 100
The solids (excluding fluorescer) were mixed together and
dosed ito a FUKAE FS-30 batch mixer. A fluorescer, mixture
containing 0.2 parts fluorescer having a nonionic/fluorescer/
water ratio) as listed in Table 3 was then sprayed onto the
solid with mixing and the Na LAS and any remaining nonionic
and water~was then dosed into the mixer.
Finally, the zeolite was added as a layering material.
WO 95/13358 PCT/GB94/02458
- 17 -
TABLE 3.
EXAMPLE NONIONIC FLUORESCER HATER
7 3 1 8
8 4 1 7
9 5 1 6
6 1 5
11 7 1 4
12 8 1 3
10 13 9 1 2
14 10 1 1
Results
The F value of the 350 to 500 a fraction of the powders was
determined for the fresh powder and after 2 weeks at ambient
conditions. The results are shown in Table 4.
TABLE 4.
EXAMPLE 7 8 9 10 11 12 13 14
F Value 4 4.8 5.0 4.9 7.8 8.5 7.8 8.5
( fresh)
F Value 6.8 8.5 7.8 8.0 8.8 8.8 8.5 8.0
(2 weeks)
Powders produced in these Examples exhibit excellent colour
characteristics both as a fresh powder and after 2 weeks. A
higher proportion of nonionic in the fluorescer mixture was
found to be advantageous in providing improved whiteness
(lower 'b' value).
PCTIGB94/02458
WO 95/13358
- 18 -
~xamnle 15 to 18
Powders were produced by the same process and having the same
composition as those of Examples 7 to 14 with fluorescer
mixture compositions as follows:
EXAMPLE NONIONIC gT,TTC~RESCER
10 1 1
10 16 10 1 2
17 10 1 3
18 10 1 4
The F values of these powders (350 - 500 a fraction) were
15 determined and observed to be in excess of 8 both for the
fresh powder and after 9 days. The 'b' values were also
determined and found to be between 2.5 and 4 for fresh powder
and between 4 and 5 after 9 days. The 'b' and F values
illustrate that powders having excellent colour properties
may be obtained by the process of the invention.
