Note: Descriptions are shown in the official language in which they were submitted.
5;3
DETE GENT GRANULES
TECHNICAL. F}ELD
~; Thi~ in~ention relates to detergent compo~ 1 tion i which
-~: include; deterçlent gramlle~ containing a water-in~oluble
~`; m terial such a~ calcium carbonate. The invention al~o
~,
relates to methods of making ~uch deter~ent ompo~itions.
. ~
BAC~ ;ROlJND ART
:: ~ Deters~ent compo~itions usually contain, in addition to
a detergent active material, a detergency builder who~e
role, inter alia, is to remove hardnes ion~ from the wa~h
liquor~which would otherwise reduce the efficiency of the
detergent active material. Water-soluble phosphate
materials have been exten~ively u~ed a~ detergency
builder~. However or a number of reason~, including
eutxophication allegedly caused by phosphatei and C08t~
there ha~ been a desire to use alkali ~etal carbonates ,-
:20 especially sodium carbonat0 instead. Alkali metal
; ~ carbonate detergency builder~ ~uffer however from a number
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- 2 - C.3069
of disadvantages. Firstly, the reaction between the
alkali metal carbonate and calcium ions which are present
in hard water results in the formation of water insoluble
calcium carbonate which, depending on the conditions, may
be in such a form as to become deposited on the washed
fabrics. Secondly, the reaction between ths alkali metal
carbonate and the calcium ions of the water is slow,
especially at low temperatures and is readily inhibited by
materials which act as calcium carbonate precipitate
growth inhibitors, referred to herein as poisons. ~he
result of this is that the concentration of calcium ions
in the wash liquor is not reduced as far or as fast as
desired, so that some free calcium ions are still
available to reduce the efficiency of the detergent active
~ 15 material~
; ~ .
As a possible solution to this problem it has been
proposed to include in the detergent composition, a
water-insoluble material which would act as a seed crystal
-~ 20 for the precipitated calcium carbonate and would adsoxb
the poisons from the wash liquor. Among other materials,
finely divided calcite has been proposed as such a
material - see British Patent Specification GB 1 437 950
(UNILEVER).
~5
However, the inclusion of calcite in detergent
compositions is hampered by its physical form. One might
consider putting small particle size calcite in a slurry
together with other ingredien~s for spray-arying, but we
have found that where alkali metal silicates are included
this process leads to a loss of calcite seed activity as a
result of poor dispersibility. Calcite having a large
surface area is preferred for maximum seed activity, but
generally such material has a relatively small particle
size, is dusty and is therefore difficult to handle. One
- alternative is to handle the calcite in a slurry, without
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~276~3S3
- 3 - C.3069
drying to a powder, but this could also involve high
storage and transport costs. It is therefore necessary to
granulate the calcite, for example by conventional
techniques of pan granulation or spray-drying, and to keep
any silicate away from the calcite. The term
"granulation" is used herein to mean any process of
agglomerating fine particles into granules of a suitable
size for incorporation into, or use directly as, detergent
compositions.
Granulatio~ of the calcite with a suitable binding
agent has been proposed, for example in British Patent
`~ Specification GB 1 515 273 (UNILEVER). However, in order
to be effective in its intended role in the wash liquor,
it is necessary for the calcite to disperse rapidly when
the product is added to water. Binding agents have
generally been found to seriously reduce the
dispersibility of the calcite.
~ .
Attempts to granulate calcite with materials known to
be good dispersing agents, for example some nonionic
detergent active materials, have also not been successful.
The resulting granules may not have the necessary
mechanical strength to solva the handling problems of the
calcite, Attempts to dis ~ er a material which will act
both as an adequate binding agent and a dispersant have
not so far been successful.
The problem is further complicated by the fact that
some binding agents and dispersing agents proposed in the
prior art are themselves poisons and will therefore
reduce the seed activity of the calcite, thereby further
adding to the problems which the calcite is intended to
solve.
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DISCLOSUR F THE INVENTION
We have now surprisingly discovered that granulation
with a specif ic mixture of materials can lead to granules
havin~ acceptable mechanical strength and disper~ibility
without 10~5 of ~eed activity.
Therefore, according to a first aspect of the
invention, there is provided a detergent composition
comprisin~;
a) at least 5% by weight of the composition of
silicate free detergent granules having an
average size between 150 and 1800 microns and comprisings
i) at lea~t 15% by weight of water-insolubl~
particulate carbona~e material which has a surface area o~
at least lOm2/g, which i~ a seed crystal for calcium
carbonat~ and which is selected from calcite, ~aterit~,
aragonite and mixtures thereof;
ii) at least 2% by weight of a non-soap detergent
active material which i~ a dispersant for the water-
insoluble particulate carbonate material and which i8
selected from non soap anionic detergent active material,
nonionic detergent active materials and mixture~ thereof;
iii) at least 5% by weight of a ~ugar selected from
monosaccharides, di~accharide~, polysaccharides, alcohol or
acid derivatives of the foregoing, degraded starch,
chemically modified degraded starch which i8 capable of
forming a clear solution or ~table colloidal dispersion in
~B~
.
- ~,
:. - . . . . . . `
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~27~i~353
- 4a -
distilled water at room temperature at a concentration of
0.01 g/l, and mixtures thereof;
Said percentages being ba~ed on the total weighk
of ingredient~ (i), (ii) and ~iii)~ and
b) from 5% to 75~ ky weight of the composition of an
alkali metal carbona~e.
' .
THE 5UGAR
As indicated previously the sugar may be a mono-, di-
or poly saccharide or a derivative thereof, or a da~raded
~tarch or chemically modified degraded starch which i~
water soluble. The saccharide repeating unit can have as
few a~ fi~e carbon atoms or a~ many as fity carbon atom~
.~ con~i~tent with water solubility. The saccharide
derivative can be an alcohol or acid of the saccharide a~
de~cribed in ~ehning~r's Biochemi~try (Worth 1970). By
~: ''water-solublell in the present context it i~ meant that thesugar i8 capable of forming a clear solution or a ~table
colloidal di~per~ion in distilled water at room temperature
a~ a concentration of 0.01 g/l.
Among~t the sugar~ ~hich are usQful in thi~ invention
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- 5 - C.3069
are sucrose, which is most preferred for reasons of
availability and cheapness, glucose, fructose, maltose
(malt sugar) and cellobiose and lactose which are
disaccharides. A useful saccharide derivative is
sorbitol.
We are aware of United States Patent Specification
US-A-3 615 811 (BARRETT assigned to C~EMICAL PRODUCTS
CORPORATION) which discloses the use o sugars as binding
agents for alkaline earth metal carbonates, particularly
barium carbonate, for use in the ceramic industry. For
this purpose less than 5~ binder is recommended for use.
We are also aware of British Patent Specification
.
GB-A-I 568 420 (COLGATE-PALMOLIVE COMPANY) which discloses
the use of water-soluble organic materials, including
sugars, as binding agents for aluminosilicate detergency
builder materials, such as fin~ly divided zeolites, to
improve the handling properties thereof.
Som~ inorganic salts can have a deleterious effect on
the properties of the granule. Alkali metal silicates for
example should be avoided. It is believed that silicates
act to cement together the particles of the
water-insoluhle carbonate material in such a manner as to
severely reduce their seed activity, this activity not
~ being regained when the granule is added to w~ter. If
;~ any water-soluble silicate material is present in the
additive the weight ratio thereof to the water-insoluble
carbonate material should ~e less than 1:10, preferably
less than 1:100.
THE WATER-INSOLUBLE PARTICULATE CARBONATE MATERIAL
The granule necessarily contains a water-insoluble
particulate carbonate material. This material must be
capable of acting as a seed crystal for the precipitate
.
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76~3~3
~ 6 - ~.3~69
. which results from the reaction between the calcium
hardnes~ ~ons of the water and the water-soluble
carbonate. Thus this water-insoluble particulate
material is a seed crystal for calcium carbonate, such as
calcium carbonate itself.
The water-insoluble particulate carbonate material
should be finely divided, and should have a surface area
of at least 10 m2/g, and preferably at least 15 m2/g.
The particularly preferred material has surface area from
30-100 m2/g. Insoluble carbonate material with surface
areas in excess of 100 m2/g may be used, if such materials
are economically available.
Surface area is measured by ni~rogen adsorption using
the standard Bruauer, Emmet & Teller (BET) method. A
suitable machine for carrying out this method is a Carlo
Erba Sorpty 1750 instrument operated according to the
manufacturer's instructions.
It is most preferred that the high surface area
~ .
material be prepared in the absence of poisons, so as to
retain its seed activity.
~-~ 25 The insoluble carbonate material will usually have an
average particle size of less than 10 microns, as measured
by conventional techniques.
; ~ .
When the insoluble carbonate material is calcium
carbonate, any crystalline form thereof may be used or a
mixture thereof, but calcite is preferred as aragonite and
vaterite are less readily available commercially, and
calcite is a little less soluble than aragonite or
~aterite at most usual wash temperatures. When any
aragonite or vaterite is used it is generally in admixture
with calcite. In the following general description, the
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- 7 - C~3069
term 'calcite' is used to mean either calcite itself or
any other suitable water-insoluble calcium carbonate seed
material.
T~E NQN-SOAP DETERGENT ACTIVE MATERIAL
The granules should contain a non-soap detergent
active material as a dispersant for the calcite. Water-
soluble nonionic or anionic detergent active material~ ormixtures thereof are preferred, although semi-polar,
zwitterionic, amphoteric or cationic detergent active
materials may also be used, alone or in admixture with
other detergent active materials. The use of an anionic
~; 15 detergent active material results in the added benefit of
reducing the calcium carbonate deposition on fabrics.
The detergent ac~ive material is prefera~ly one which
does not form a substantially insoluble calcium salt, as
the presence of calcium ions in the wash liquor might
then hinder the dispersibility of the granules. Soaps
~ which do form a substantially insoluble calcium salt are
; therefore not preferred as the only detPrgent active
material in the granules.
2S It is important that the dispersant does not act as a
poison. The preferred dispersant is an anionic material
such as an alkyl benzene sulphonate, especially where the
alkyl group is linear. We have found that these
materials do not act as poisons in the present context.
This is surprising in view of the disclosures of Canadian
Patent Specification CA-A-991 942 (BENJAMIN, granted to
; THE PROCTER & GAMB~E COMPANY) which teaches that certain
anionic detergents interfere with the growth of free metal
ions on a crystallisation seed.
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- 8 - C. 3069
THE COMPOSITION OF THE GRANULE
The level of calcite in the granules is preferably at
least 15~ by weight, most preferably at least 40~ by
~eight. Below these levels it would be necessary to
include too high a level of granules in the overall
detergent composition, leaving insufficient space for
other ingredients.
The level of detergent active in the granules is
preferably more than 2~ by weight, most preferably at
least 5% by weight. Below these levels, dispersibility
of the granules may be unsatisfactory.
~-~ 15 The level of sugar in the granules i~ preferably more
than 5~ by weight. Below this level, the mechanical
strength of the granules may be unsatisfactory.
The above percentage levels are based on the total
weight of the calcite, detergent active and sugar in the
granule. Other components may also be present in the
granules, up to a total of preferably no more than 50%
most preferably up to about 25% by weight of the
granules. Thus water will usually be present to an
extent determined by the processing method involved.
; Other components which may have a beneficial effect on
the overall detergent composition may also be present,
provided that they do not have a serious effect upon the
seed activity, dispersibility and mechanical strength of
~ 30 the granules. Thus for examp~e further dispersants
; and/or further binding agents may be present.
.
The presence of water-soluble flow aids such as
sodium sulphate or carbonate can be beneficial during a
granulation process. Sodium carbonate also has the
advantage of being a builder and it improves the granule
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- 9 - C.3069
- prsperties when used in combination with the sugar.
The granule can constitute the whole of a detargent
composition when it contains an alkali metal carbonate and
sufficient detergent active material, especially where
sodium silicate is not required to be in the composition.
Alternatively, the granule~ according to the invention
will be incorporated in a detergent composition which
separately contains other ingredients.
DETERGENT ACTIV~ MATERIALS IN THE COMPOSITION
An essential component of the composition is a
detergent active material. This material may be selected
from anionic, nonionic, amphoteric and zwitterionic
detergent active compounds and mixtures thereof, which
often do not form during use at normal product
concentration in hard water excessively water insoluble
calcium salts; this ensures that the detergent active
compound is not precipitated as its calcium salt instead
of calcium carbonate being precipitated. Some degree of
precipitation of the detergent active compound or mixture
of compounds in the form of the calcium salts may be
tolerated, provided that after allowing for the subsequent
redissolution of any of the calcium salt during the
washing process, the amount of any more permanent
precipitate is minor and an effective amount of detergent
active compound i5 left in solution.
Many suitable synthetic detergent active compounds
are commercially available and they are fully described in
the literature, for example in "Surface Active Agents and
Detergents" Volumes 1 and 2~ by Schwartz, Perry and Berch.
:
The preferred detergent active compounds are fully
described in GB 1 437 950 referred to above.
.
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- 10 - C.3069
However, because the present invention enables the
calcite to be rapidly dispersed, the use of soaps (and
similar long chain carboxylates such as succinates,
- malonates and sulphonated fatty acid salts) as detergent
actives separate from the calcite gxanules is now made
possible.
The effective amount of the detergent active
compounds or compounds used in the compositions is
generally in the range from 5 to 40% by weight, preferably
not more than 30~ by weight of the composition.
THE WATER-SOLUBLE CARBONATE MAT~RIAL
A further essential ingredient of the composition is
a water-Qol-1ble car~onate material as a builder. This is
~; ~ preferably sodium or potassium carbonate or a mixture
thereof, for reasons of cost and e~ficiency. The
`~ carbonate salt is preferably fully neutralised but it may
be partially neutralised, for example a sesquicarbonate
~- may be used in partial replacement of the normal carbonate
salt; the partial salts tend to be less alkaline and
~:~ therefore less efficient. The amount of water-soluble
carbonate material in the detergent composition can be
varied widely, but the amount should be at least S~ by
~; weight, such as from 10~ to 40%, preferably 10~ to 30% by
weight, though an amount o~ up to 75% could possibly be
used if desired in special products. The amount of the
water soluble carbonate material is determined on an
30 anhydrou~ basis, though the salts may be hydrated either
before or when incorporated into the detergent
composition. It should be noted that it may also be
desirable to limit the carbonate content to a lower level
within the range mentioned, so as to decrease the risk of
internal damage following any accidental ingestion, for
example by children.
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~ C.3069
The selected level of calcite in the overall
composition depends on the specific surface area as
described above. The amount of calcite used in the
compositions wîll usually be Erom 5% to 60~ depending on
the calcite surface area, typically from 5~ to 30~.
The granules should occupy at least 5% of the overall
composLtion, preferably from about 10% to about 40% of
the overall composition.
The size of the granules should be compatible with
the remainder of the detergent composition, preferably in
the average size range of 150 to 1800 microns, as measured
by sieve analysis, most preferably from 180 to 1500
microns.
~:~ 15
OTHER INGREDIENTS OF THE COMPOSITION
In addition to the granules, the detergent active
material and the water-soluble carbonate material it is
possible to include minor amounts of other detergency
builders, provided that the total amount of the detergency
builders does not exceed 85% by weight, so as to leave
room in the detergent composition for other desirable
ingredients.
Where a soap is used as a detergent active material
it may be present in such a quantity that it will also
contribute as an additional builder.
Apart from the calcite granules, the detergent active
compounds and detergency builders, the detergent
composition can optionally contain any of the conventional
ingredients in the amounts in which such ingredients are
normally employed in fabric washing detergent
compositions. Where the calcite granules constitute the
whole of the composition, these ingredients can be
.
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- 12 - C.3~69
included in the granules.
One such optional ingredient is an alkali metal
silicate, particularly sodium neutral, alkaline, meta- or
orthosilicate. A low level of silicate, for example
5-10~ by weight, is usually advantageous in decreasing the
corrosion of metal parts in fabric washing machines, and
it may give processing benefits. If higher levels of
silicate are used up to a practical maximum of 30%, for
example from 10~ to 20% by weight, there can be a more
noticeable improvement in detergency, which may permit
some decrease in the water- soluble carbonate material
;~ content. This effect appears to be particularly
~-; beneficial when the wash liquor are used in water with
appreciable levels of magnesium hardness. The amount of
silicate can also be used to some extent to control the
equilibrium pH of the wash liquor, which is generally
within the range of 9-11, preferably 10-11 for an aqueous
solution of the composition at the recommended
concentration. It should be noted that a higher pH (ie
over p~ 10.5) tends to be more efficient as regards
detergency, but it may be less desirable for domestic
safety. Sodium silicate is commonly supplied in
concentrated aqueous solution, but can be obtained as a
~ree flowinq powder. The amounts of silicate are
calculated on an anhydrous basis.
Examples of other optional ingredients include the
lather boosters such as alkanolamides, particularly the
monoethanolamides derived from palm kernel fatty acids and
coconut fatty acids, lather depressants, oxygen-releasing
bleaching agents such as sodium perborate and sodium
percarbonate, peracids, peracid bleach precursors,
chlorine-releasing bleaching agents such as
trichloroisocyanuric acid, fabric softening agents,
anticorrosion agents, inorganic sal~s such as sodium
.
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- 13 - C~3069
sulphate, and, usually present in very minor amounts,
fluorescent agents, perfumes, enzymes such as proteases
and amylases, germicides and colourants. A particularly
effective bleaching agent is sodium perborate monohydrate
having a surface area in excess of 5 m2/g and a positive
caking index as described in European Patent Specification
EP-A-164 778 (UNILEVER). Particularly when the
composition does not contain an anionic detergent active
material, it can be beneficial to include an anti-ashing
material such as described in European Patent
Specification EP-A 126551 (UNILEVER) to reduce the
deposition of calcium carbonate onto fabrics.
PRODUCTION OF THE COMPOSITIONS
The detergent compositions may be produced by any of
the techniques commonly employed in the manufacture of
fabric washing detergent compositions, including
particularly slurry-making and spray-drying processes for
~ 20 the manufacture of detergent powders.
". ' '
The calcite granules may be prepared by thP
conventional techniques of agglomerating by means of a
mechanical granulator such as an Eirich pan, or by spray
drying.
:~ .
In addition to the calcite granule, other granules
can be prepared containing for example further detergent
active, and silicate, for example by spray-drying, and
these two granules are then mixed together, optionally
along with other ingredients, in particular any sensitive
ingredients such as bleaches and perfumes. If the
calcite granule already con~ains sufficient detergent
active material for the composition as a whole, these
other granules may comprise sodium silicate or sodium
silicate granula~ed with an inorganic salt such as sodium
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- 14 - C.3069
carbonate.
It will be seen from above and from the examples
which follow that the calcike granules according to the
invention provide benefits of acceptabl~ mechanical
strength, dispersibility and retained seed activity and
where anionic detergent actives are involved, additionally
the benefit of reduced deposition on fabrics.
The invention will now be illustrated by the
~ollowing non-limiting example~.
EXAMPLE 1
-~ 15 A detergent granule was prepared having the following
formulation, by preparing a slurry of the stated
ingredients and spray-drying ~o the stated moisture
~- content.
20 Ingredient Parts by Weight
Anionic detergent active 4.0
~ - "
Sodium carbonateC 10.0
Calcite3 20.0
Sucrose 4.0
25 Moisture4 1.2
Total 39.2
Notes:
: i B 30 1 - Dobanè~ 13 (ex Shell Chemicals) which is sulphonated
to form approximately a sodium alkyl benzene
sulphonate in which the alkyl group contains from 10
to 15 carbon atoms.
2 - Measured as anhydrous.
` 35 3 ~ Socal U ~ (ex Solvay) having a nominal surface area of
100 m2/g~
le~fes troe~e ~
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~ 15 - C.3069
4 - Total water content including water of
crystallisation.
Using a conventional spraying technique, 2.0 parts by
weight of a nonionic detergent active material Synperonic
A7 (ex ICI - an alcohol having an alkyl chain length of
13-15 carbon atoms ethoxylated with an average of 7
ethylene oxide groups per molecule) was sprayed on to the
spray-dried calcite gxanules.
A spray-dried base powder was prepared having the
following formulation, by preparing a slurry of the stated
ingredients and spray-drying to the stated moisture
content.
In~redient Parts by Wei~ht
Dobane 113~y 7.0
L~ Synperonic1~A7 2.0
20 Sodium carbonate 20.0
~- Sodium silicate5 8.0
Minor conventional ingredients 1.2
~- Moisture 5~5
Total 43,7
Note:
.; ~
5 - Measured as anhydrous.
~: .
The calcite granules, the spray-dried base powder and
further ingredients as specified below were then drymixed
together to form the final product.
;
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- 16 - C.3~69
- IngredientParts by Weiyht
Calcite granules 41.2
Base Powder 43-7
Conventional foam control agent 1.5
5 Sodium perborate monohydrate 13.0
Perfume 0.2
Enzyme 0-4
Total 100.0
EXAMPLE 2
The following example demonstrates that where sodium
carbonate is an ingredient in the calcite granules, the
order of addition of the granule ingredients to ~he slurry
is critical.
:
A slurry was prepared according to the following
~ formulation by mixing the ingredients in the order stated.
:
20 In~redient Parts by weight
- `.
Water 25
Anionic detergent active7 4
- Calcite6 20
25 Sodium carbonatell 10
-~ Sucrose 4
: ' .
Notes:
; 30 6 - As Examp~,e 1
7 - Petrelab~550 (ex Petresa) which is approximately
sodium alkyl benzene sulphonate in which the alkyl
group contains from 10 to 15 carbon atoms.
11 - Measured as anhydrous
~o/e~t~s t~
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- 17 - C.3069
The slurry at a temperature of 80C was pumped via a
high pressure pump (at about 40 bar pressure) to an
atomising jet. The atomised sluxry was dried in a spray
drying tower by hot air using conventional procedures and
conditions. The air temperature was about 300C. The
physical properties, i.e. bulk denqity, cohesiveness and
strength of the granules were found to be satisfactory in
comparison with commercially available products.
1 0
The performance of the granules was tested as
follows:
: .
The granules were added to 1 litre of 20 FH calcium
chloride solution (calcium ion concentration 20 x 10 4
molar) in a Tergotometer (Trade Mark), laboratory sc~le
apparatus at 25C and in an amount equivalent to 0.5 g/l
calcite together with sufficient sodium carbonate tq make
a total of 1.5 g/l. The wash liquor was agitated for 15
minutes at 100 rpm. The activity of the granules was
determined using as a detergency monitor an artificially
soiled test cloth which was present throughout the wash
and known to be sensitive to the level of hardness ions
in solution. The change in reflectance of the test cloth
;~ 25 achieved with the granules was compared with that achieved
by a mixture of the same components where the calcite was
added as the raw material.
By this method these granules were found to have a
performance of 50~ that of the calcite raw material.
When the experiment was repeated with the exception only
that the calcite was added to the slurry after a quarter
of the sodium carbonate had been added, the seed activity
was found to be about 100~ of that of the calcite raw
material.
.; . - -
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- 18 - C.3069
-~ EXAMPLES 3 TO 5
Calcite and anhydrous sodium carbonate were dry mixed
and added to a pan granulator. A blend of detergent
active material, water and sucrose at 80C was sprayed on
while the granulator was operated in a conventional
manner. The level of water used was the same weight as
the detergent active material. The granules which formed
wPre dried in a fluidised bed. The granules had the
following final compositions:
Example No. 3 4 5
Ingredient ~parts by weight)
Calcite12 20.0 20.0 20.0
Sodium carbonate - 10.0 10.0
Anionic detergent active1 4.0 4.0
Nonionic detergent activeS - - 3.6
Sucrose 4.0 4.0 3.6
Water 0.5 2.0 2.0
Notes
12 - As Example 2.
8 ~ Synperonic 7EO.
The physical properties i.e. bulk density,
cohesiveness and strength of the granules made according
to Examples 3 and 4 were found to be satisfactory in
comparison with commercially available products.
The mechanical strengths of the qranules were
measured using a friability test, in which a sample of the
material to be tested is subjected to a spiral air flow.
The per~entage of fine particles, having a size of less
~ than 150 microns, is measured before and after the test.
:.
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- 19 - C.3069
Any increase in the level of fine particles is an
indication of the friability and therefore the mechanical
strength of the material. An increase of lO~ or less in
the level o~ fine particles is considered to be
acceptable.
Results were obtained as follows:
Example No: 3 4 5
10 ~ increase in fi~e particles - 4% 2~
The performance of these granules was measured as
described in Example 2. The performance of the granules
according to Examples 3 and 4 was found to be
lS approximately 100% of the calcite raw material. The
performance of the granule according to Example 5 was
; found to he about 50% of the raw material. This
demonstrates a benefit for the use of an anionic
detergent active in the granules.
EXAMPLE 6
Calcite granules were prepared in the laboratory by
evaporating a hand-stirred dispersion of calcite in an
aqueous solution of anionic detergent active and/or
sucrose to near dryness on a steam bath, completiny the
drying in an oven overnight at 80 - 100C, grinding the
dried mass with a pestle and mortar, and sieving to obtain
30 355-1000 microns particles. A Wallace Micro-Indentation
Tester was used to provide a quantitative determination of
; granule strength. Seed crystal activity was determined by
adding the granules together with sodium carbonate to
water having a hardness of 20FH containing lOppm sodium
tripolyphosphate to represent a poison which may in
practice be present in a wash liquor. Using a calcium
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.. electrode which was insensitive to anionic detergent
actives, the level of free calcium ions present after 5
minutes was measured at 20C. The granules were added at
a level of 0. a4 g/l and the sodium carbonate at a level of
1.4 g/1. The composition of the granules and the results
ohtained were as follows.
Example No: 6 6A 6B
Ingredients (pa.rts by weight)_ __ _
Calcite13 15.0 15.0 15.0
Anionic detergent active13 4.0 6.0
Sucrose 2.0 - 6.0
. ~'
: 15 Granule strength(g) 100 43 240
; FH after S minutes 0.06 0.1 1.6
Notes
13 - As in Example 3.
These results demonstrate that while the use of
sucrose alone (Example 6B) provides mechanical strength,
the performance of the granules is poor. The use of
anionic detergent active alone (Example 6A) provides
better performance, but mechanical strength i5 poor. The
: use of both ingredients (Example 6) gives acceptable
: mechanical strength and good performance.
EX~MPLE 7
~ The following granule formulation represents a
`~ silicate-free granule which can constitute the whole of a
detergent composition for use in conditions where the
. presence of sodium silicate is not essential:
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- 21 - C.3069
Ingredient % by wei~ht
Anionic detergent acti~e 25
Sodium carbonate 40
Calcite 20
5 Sucrose 5
Sodium sulphate 3
Minor ingredients and water 7
EXAMPLE 8
The following formulation represents a silicate
containing composition which can be prepared by
: pan-granulating the calcite granules and adding them to a
: 15 spray dried base powder together with other ingredients.
~ Ingredient ~ by weight
- Calcite granules: .
Calcite 12
: Anionic detergent active 3
Sucrose 1.5
Spray-dried base:
Anio~ic detergent active 5
~ Nonionic detergent active 2
:~ Foam control agent 1.2
Sodium carbonate 35
Sodium alkaline silicate 8
Sodium sulphate 6
~ .
' Other ingredients
. ~
Sodium perborate tetrahydrate 18
Minor ingredient~ 1.2
Total water balance
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- 22 - C.3069
EXAMPLES 9 TO 20
The following granules were prepared by spray drying
(parts by weight):
~; Example No: 9 10 11 12 13 14 15 16 17 18 19 20
Ingredient:3 -
Calcite14 20 20 20 20 20 20 20 20 20 20 20 20
Sodium carbonate15 10 10 10 10 10 10 10 10 10 10 ~ 10
Anionic active14 4 4 4 4 - - 4 4 4 4 4 4
Soap _ _ _ _ 416 417
Sucrose 4 - - - 4 4 l 3 5 7 4
Sorbitol - 4
15 Maize starch - - 4
;~ Lactose ~ 4
~; Neutral silicate - - - 4 - - - - ~ ~ ~
~; Silica ~ - 5
Moisture -~ --- 1.2 --~
~ .
Notes:
14 - As Example 1.
15 - Measured as anhydrous.
16 Coconut soap (sodium)
25 17 - ~ard~ned tallow soap (sodium)
A slurry was prepared having a nominal water content
of 40% as follows. To 18.8 parts water was added 5 parts
of sodium carbonate. 8.5 parts of anionic active in
paste form was then added (being equivalent to 4 parts of
the active material calculated on an anhydrous basis).
4 parts of the binding agent were added followed by
20 parts of calcite powder. Finally a further 5 parts of
sodium carbonate were added. The slurry was then spray
; 35 dried to a moisture content of 1.2 parts.
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- 23 - C.3069
This process was modified as necessary to provide the
different formulations given above.
When lactose in the form of dried whey powder was
used as the binder it was necessary to add further water
to the slurry to make it pumpable.
. .
The maize starch used as a binder was not
dispersible in the slurry and produced an off-colour
product.
Example 9 is similar in formulation to Example 1.
Examples 10, 11 and 20 utilize different sugar materials
in place of the sucrose. In Example 12 (comparative~ the
granules contain silicate as a binder in place of the
-~ sucrose. In Examples 13 and 14 (comparative~ the
granules contain soap in place of the synthetic anionic
detergent active. In Examples 15 to 18, the level of
sucrose in the granules is progressively increased. In
Example 19, the granules further contain silica, but no
sodium carbonate.
These granules were tested in a number of different
ways as explained in more detail below.
: ,~
In a seed activity test the granules were added to 1
litre of water at 25C having a hardness of 20~F~ (20 x
10 4 molar free calcium ions) containing 10 ppm sodium
tripolyphosphate at a dosage corresponding to 1 g~l
calcite. The free calcium ion concentration was measured
after 15 minutes. Results 1ncluded the following:
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- 24 - ~.3069
. Free Calcium
(g ion/l tre
Example_No Granule Type x 10 ?
9 Calcite/carbonate/sucrose/anionic 0.044
12 Calcite/carbonate/silicate/anionic 0.210
13 Calcite/carbonate/sucrose/soap 1.100
14 Calcite/carbonate/sucrose/soap 0.560
lg Calcite/silica/sucrose/anionic 0.080
:,' 10
These results illustrate that the granules of
comparative example~ 12, 13 and 14 all showed poor seed
activity. All other granules tested showed a seed
activity at least as good as Example 19.
In a machine dispensibility test, 150 g of the
granules were placed in the dispenser of a HOOVER (Trade
Mark) automatic washing machine. Cold water was allow~d
to enter the dispenser at a rate of 2 litres per minute
for 2 minutes. The water had a hardness of 24FH. The
water pressure was 5 psi. ~fter allowing the water to
drain naturally out of the dispenser, the weight of the
powder residue therei~ was measured. Results included
the following:
Wet Residue
Example No Granule Type (g)
9 Calcite/carbonate/sucrose/anionic 177
Calcite/carbonate/sorbitol/anionic 4
19 Calcite/silica/sucrose/anionic 12
These results demonstrate that sucrose can be
replaced by sorbitol to provide a significant improvement
in dispensibility, and the carbonate can be replaced by
silica to achieve a similar effect.
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- 25 ~ C.3069
A dispersibility test was also carried out as
follows. 150 cc of water is placed in a beaker and
stirred at such a rate as to gQnerate a vortex of between
5 and 10 cm. 10 g of the material to be tested is added
and the degree of dispersibility is determined by visual
estimation. Each granule was allotted a dispersibility
grade on *he basis of this test as follows:
1 = Granules are completely dispersible.
2 = ~75% of granules are dispersible.
3 = >50% of granules are dispersible.
4 - >2S~ of granules are disperxible.
5 = All powders clotted.
'
The results were as follows:
Example No Granule Type Dis~ersibility_Grade
;~ 15 1 paxt sucrose 2
- 16 3 parts sucrose 3
9 4 parts sucrose 3
17 5 parts sucrose 3
18 7 parts sucrose 3-4
A friability test was also carried out, as described
in Examples 3-5 above and the results were as follows:
Granule Type % Fines
13 Calcitetcarbonate/sucrose/soap 12.3
17 5 parts sucrose 9.3
All other granules tested from Examples 9-20 had an
` increase in the percentage of fines o~ 8.9~ or less.
; These results demonstrate that the use of soap in place of
a non-soap anionic active material produces a granule with
~; 35 unacceptable mechanical strength.
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- 26 - C.3069
EXAMPLES 21 AND 22
Two powder~ having the following nominal formulation
were prepared by pan granulation using an Eirich (Trade
Mark~ pan.
Example ~o: 21 22
In~redients
- 10 Calcitel8 20 20
Sodium carbona~el9 10 lO
Anionic activel8 4
Sucrose 4 4
Moisture 1.2 1.2
Notes:
~ .~
18 - As Example 1.
19 - Measured as anhydrous.
The granules of Example 21 were prepared by ~praying
a mixture of the anionic active paste, sucrose and water
onto a mixture of calcite and sodium carbonate solids.
The granules of Example 22 were prepared by a two-stage
spray-on technique. Firstly an anionic active
paste/water mixture is sprayed on to a mixture of calci~e
and sodium carbonate solids, and ~hereafter a sucrose
solution in water is sprayed on. In both cases exce~s
water in the yranules is removed by tray drying in an oven
at 70C.
.': .
These granules were tested in the same way as those
in Examples 9 to 20 and results were as follows:
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- 27 - C.3069
. ~xample No. 9 21 22
Seed activity
~free Ca++ g ion/l x 10 4) 0.044 0.036 0.046
Machine dispensibility
(g wet residue) 177 95 88
Mechanical strength
10 (~% fines~ 3.1 12.8 3.7
These results demonstrate that granules with greater
m~chanical strength ars obtainable when the sucrose is
sprayed on separatsly from and subse~uent to spraying on
the anionic active.
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