Note: Descriptions are shown in the official language in which they were submitted.
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DETERGENT COMPOSITIONS
AND PROCESS FOR PREPARING THEM
TECHNICAL FIELD
The present invention relates to granular detergent compositions
and components of high bulk density, and their preparation by a dry
neutralisation process.
BACKGROUND AND PRIOR ART
Recently there has been considerable interest within the detergents
industry in the production of detergent powders having relatively high
bulk density, for example, 650 g/litre and above. It has been suggested that
such powders containing anionic surfactants, for example alkyl benzene
sulphonate, may be prepared by methods involving in-situ neutralisation
of an acid precursor of the anionic surfactant with an alkali such as sodium
hydroxide or sodium carbonate
For example, JP 60 072 999A (Kao), published April 25, 1985 and
GB 2 166 452A (Kao), published May 8, 1986 disclose a process in which
detergent sulphonic acid, sodium carbonate and water are mixed in a
strongly shearing apparatus; the solid mass obtained is cooled to 40C or
below and pulverised; and the fine powder thus obtained is granulated.
This process is typical of those disclosed in the art in that the product of theneutralisation reaction is a doughy mass, and the reaction requires
apparatus such as a kneader with a very high energy requirement; and
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separate pulverisation and granulation steps in different apparatus are
required in order to obtain an acceptable granular detergent product.
There has also been considerable recent interest in the use of high-
5 speed mixer/granulators in the preparation of high-bulk-density detergent
powders. For example, EP 158 419A (Hashimura), published
October 16, 1985 discloses a process in which nonionic surfactant and soda
ash are mixed and granulated in a reactor having horizontal and vertical
blades rotating at different speeds, to give a detergent powder built with
10 sodium carbonate and containing a high level of nonionic surfactant.
GB 1 404 317 (Bell), published August 28, 1975 discloses the
preparation of a detergent powder of low or moderate bulk density by a dry
neutralisation process. Detergent sulphonic acid is mixed with an excess of
15 soda ash in the presence of sufficient water to initiate the neutralisation
reaction but not enough to wet the resultant product, which is in the form
of a free-flowing powder. The process is carried out in apparatus, for
example a ribbon blender, planetary mixer or air transfer mixer, in which
the reactants are "tossed and fluffed", and carbon dioxide liberated during
20 the neutralisation is entrapped in the product particles. The process is thus
directed towards the production of light, porous particles comparable to
those obtained by spray-drying.
GB 1 369 269 (Colgate), published October 2, 1974 discloses a process
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for the production of anionic detergent, by vigorously mixing detergent
sulphonic acid with powdered sodium carbonate in a mixer with a cutting
arrangement, for example a Lodige ploughshare mixer. In order to obtain a
granular product rather than a doughy mass, it is necessary to blow the
5 detergent sulphonic acid in by means of a gas stream, to ensure adequate
fluidisation and mixing of the reactants: this requires quite complex
modification of the mixer. No water is added to promote the neutralisation
reaction, which therefore proceeds slowly and produces a relatively coarse
product requiring an additional size reduction step. The temperature
10 during neutralisation typically rises to about 85C.
US 4 690 785 (Witco), published September 1, 1987 discloses a process
for the production of alkylbenzene sulphonate powder by the neutralisation
of alkylbenzene sulphonic acid with a base in solid or solution form. A
15 substantial amount of water is present at the beginning of the process, and
the heat generated by the exothermic reaction is used to drive off this, and
the water generated by the reaction itself; reaction temperatures of about
100C are typical.
The present inventors have now discovered that free-flowing
detergent powders and detergent powder components of high bulk density
and small particle size can be produced by dry neutralisation at relatively
low temperatures, using only a single piece of apparatus: a high-speed
mixer/granulator having both a stirring action and a cutting action.
1 3 3 7 5 1 3
DEFINITION OF THE INVENTION
The present invention accordingly provides a process for the
preparation of a granular detergent composition or component having a
5 bulk density of at least 650 g/litre, which process includes the step of
neutralising a liquid acid precursor of an anionic surfactant with a solid
water-soluble alkaline inorganic material, the process being characterised by
the steps of:
10 (i) fluidising a particulate solid water-soluble alkaline inorganic
material in an amount in excess of that required for neutralisation,
optionally in admixture with one or more other particulate solids, in a
high-speed mixer/granulator having both a stirring action and a cutting
action;
15 (ii) gradually adding the acid precursor to the high-speed
mixer/granulator, while maintaining a temperature not higher than 55C,
whereby neutralisation of the acid precursor by the water-soluble alkaline
inorganic material occurs while the mixture remains in particulate form;
(iii) granulating the mixture in the high-speed mixer/granulator, in the
20 presence of a liquid binder,
whereby a granular detergent composition or component having a bulk
density of at least 650 g/litre is formed.
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The invention also provides a granular detergent composition or
component prepared by this process.
5 DETAILED DESCRIPTION OF THE INVENTION
The process
DETAILED DESCRIPTION OF THE INVENTION
The subject of the invention is the preparation of high-bulk-density
detergent powder by a process involving the dry neutralisation of the acid
10 precursor of an anionic surfactant with an alkaline solid. The process is
carried out in a high-speed mixer/granulator and involves the previously
defined process steps (i), (ii) and (iii).
A very important characteristic of the process of the invention is that
15 the reaction mixture remains throughout in particulate or granular form.
Caking, balling and dough formation are avoided, and the product at the
end of the granulation step needs no further particle size reduction. The
process of the invention generally produces a granular product containing
at least 50 wt%, preferably at least 70 wt%, of particles smaller than 1700
20 microns. This is achieved by ensuring that liquid components, particularly
the acid anionic surfactant precursor, do not have an opportunity to act as
binders or agglomerating agents.
First, step (i) ensures that there is initially a large amount of
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particulate solids present, relative to the liquids to be added, in the mixer
before the introduction of the liquids. Preferably the total solids present in
step (i) amount to at least 60 wt%, more preferably at least 67 wt%, of the
total composition present in step (ii). It is therefore advantageous to add as
5 high a proportion as possible of the solid ingredients of the final product at
this stage.
Preferably the liquids to solids ratio at the end of the neutralisation
step (ii) does not exceed 0.60; more preferably it does not exceed 0.55, and
10 desirably it does not exceed 0.50.
The solids must of course include a particulate water-soluble alkaline
inorganic material (neutralising agent), in at least slight excess over the
amount required for neutralisation. The terms "particulate solid water-
15 soluble alkaline inorganic material" and "neutralising agent" used hereinof course include combination of two or more such materials. If the
neutralising agent is a material that itself can play a useful role in the final
composition, substantially larger amounts than this may be used.
According to a preferred embodiment of the invention the
neutralising agent comprises sodium carbonate, either alone or in
admixture with one or more other particulate water-soluble alkaline
inorganic materials, for example, sodium bicarbonate and/or sodium
silicate. Sodium carbonate is of course also useful as a detergency builder
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and provider of alkalinity in the final composition. This embodiment of
the invention may thus advantageously be used to prepare detergent
powders in which sodium carbonate is the sole or principal builder, and in
that case substantially more sodium carbonate than is required for
5 neutralisation may be present.
The sodium carbonate embodiment of the invention is also suitable,
however, for the preparation of detergent compositions in which
substantial amounts of other builders are present. Those other builders
10 may also advantageously be present in the high-speed mixer/granulator in
step (i). Examples of such builders include crystalline and amorphous alkali
metal aluminosilicates, alkali metal phosphates, and mixtures thereof.
Sodium carbonate may nevertheless be present in excess of the amount
required for neutralisation, in order to provide alkalinity in the product: an
15 excess of about 10 to 15 wt% is then suitable.
The solids present in step (i) may also include any other desired solid
ingredients, for example, fluorescers; polycarboxylate polymers;
antiredeposition agents, for example, sodium carboxymethyl cellulose; fatty
20 acids for in-situ neutralisation to form soaps; or fillers such as sodium
sulphate, diatomaceous earth, calcite, kaolin or bentonite.
If desired, solid particulate surfactants, for example, alkylbenzene
sulphonate and/or alkyl sulphate in powder form, may form part of the
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solids charge in step (i). Thus, for example, a detergent powder prepared by
the process of the invention may contain alkylbenzene sulphonate in part
introduced as a powder in step (i), and in part prepared in situ in step (ii).
Alternatively or additionally a spray-dried detergent base powder
may form part of the solids charge in step (i).
According to one preferred embodiment of the invention, the solids
present in step (i) include a finely divided particulate flow aid. This is
suitably present in an amount of from 2 to 8 wt%, more preferably from 5 to
7 wt%, based on the final composition. Suitable flow aids include
crystalline or amorphous alkali metal aluminosilicate, thermally treated
perlite, calcite, diatomaceous earth, and combinations of these.
Preferred flow aids are diatomaceous earth, and, in particular,
Dicamol (Trade Mark) 424 thermally treated perlite. This material has a
silica content of 80-87 wt% and a water absorbance capacity of 250-300 wt%.
Its presence in the solids mix before and during the addition of the acid
anionic surfactant precursor appears to assist in preventing excessive
agglomeration and maintaining the reaction mix in particulate form.
It is an important feature of the process of the invention that the
solids be very efficiently mixed and fluidised before the introduction of any
liquid ingredients: the term "fluidisation" as used herein means a state of
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mechanically induced vigorous agitation in which the mass of particles is to
some extent aerated, but does not necessarily imply the blowing in of a gas.
This state is achieved by the choice of apparatus: a high-speed
mixer/granulator having both a stirring action and a cutting action.
5 Preferably the high-speed mixer/granulator has rotatable stirrer and cutter
elements that can be operated independently of one another, and at
separately changeable or variable speeds. Such a mixer is capable of
combining a high-energy stirring input with a cutting action, but can also be
used to provide other, gentler stirring regimes with or without the cutter in
10 operation.
A preferred type of high-speed mixer/granulator for use in the
process of the invention is bowl-shaped and preferably has as substantially
vertical stirrer axis.
Especially preferred are mixers of the Fukae (Trade Mark) 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
20 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.
A similar mixer manufactured in India is the Sapphire (Trade Mark)
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RMG series of rapid mixer/granulator, which like the Fukae mixer is
available in a range of different sizes. This apparatus is essentially in the
form of a bowl-shaped vessel raised up pneumatically to seal against a fixed
lid. A three-bladed stirrer and a four-bladed cutter share a single
5 substantially vertical axis of rotation mounted on the lid. The stirrer and
cutter may be operated independently of one another, the stirrer at speeds of
75 rpm or 150 rpm, and the cutter at speeds of 1440 rpm or 2880 rpm. The
vessel can be fitted with a cooling water jacket.
The Sapphire RMG-100 mixer, which is suitable for handling a 60 kg
batch of detergent powder, has a bowl of about 1 metre diameter and 0.3
metres deep; the working capacity is 200 litres. The stirrer blades are of 1
metre diameter and the cutter blades are of 0.1 metre diameter.
Other similar mixers found to be suitable for use in the process of the
invention include the Diosna (Trade Mark) V series ex Dierks & Sohne,
Germany; and the Pharma Matrix (Trade Mark) ex T K Fielder Ltd.,
England. Other mixers believed to be suitable for use in the process of the
invention are the Fuji (Trade Mark) VG-C series ex Fuji Sangyo Co., Japan;
20 and the Roto (Trade Mark) ex Zanchetta & Co srl, Italy.
Yet another mixer found to be suitable for use in the process of the
invention is the Lodige (Trade Mark) FM series batch mixer ex Morton
Machine Co. Ltd., Scotland. This differs from the mixers mentioned above
1 3375 1 3
in that its stirrer has a horizontal axis. This configuration, however, has
the disadvantage that mixing and fluidising in step (i) is less efficient, and
may need to be supplemented by the blowing in of gas as described in the
aforementioned GB 1369 269 (Colgate).
The next stage of the process of the invention - step (ii) - is the
introduction of the acid surfactant precursor. The way in which this step is
conducted is crucial to the success of the process. In particular, it is
important that throughout the neutralisation step the amount of liquid
10 present never rises to a level where it can cause substantial agglomeration.
It is believed, however, that the solids, now efficiently fluidised, have
to be wetted with just sufficient water to initiate and promote the
neutralisation reaction before they encounter the acid precursor. The
15 amount of free water present in step (ii) is therefore believed to be very
important. The term "free water" is used herein to mean water that is not
firmly bound as water of hydration of crystallisation to inorganic materials.
If insufficient is present, the reaction will not proceed rapidly, and
unreacted detergent acid precursor will accumulate in the mixer and act as a
20 binder, causing substantial agglomeration, balling up and even dough
formation. Thus it would appear that enough water to wet all the solids
should be present, but not so much that the water itself will act as a binder.
The solids themselves may contain sufficient free water for these
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conditions to be attained. For example, a spray-dried detergent base powder
blown to a relatively high moisture content could provide most or all of the
free water required. If insufficient free water is inherently present in the
solids charge, a carefully controlled amount of water should be added either
prior to or concurrently (together or separately) with the addition of the acid
precursor. To ensure thorough wetting of the solids before the introduction
of the acid precursor, all the water may be added before addition of the acid
precursor commences. Alternatively, the acid precursor and the water may
be introduced simultaneously into the mixer.
If desired, a small amount of water, sufficient to initiate the
neutralisation reaction but not sufficient to cause substantial
agglomeration, may be premixed with the acid precursor before the latter is
introduced into the high-speed mixer/granulator. If a coloured product is
desired, dyestuff may conveniently be premixed with the acid precursor and
water before addition to the high-speed mixer/granulator.
The amount of water to be added will depend on the nature of the
solids present. It has been found that an amount within the range of from
0.5 to 2.0 wt%, preferably from 0.5 to 1.5 wt%, based on the total solids
present in steps (i) and (ii), gives good results in the preferred embodiment
of the invention in which the neutralising agent is sodium carbonate.
Another important condition for step (ii) is that the acid precursor be
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added gradually, so that it will be consumed immediately and will not
accumulate in the mixer in unreacted form. The time required and
preferred for addition of the acid precursor is of course dependent on the
amount to be added, but in general addition preferably takes place over a
5 period of at least 1 minute, more preferably over a period of from 2 to 12
minutes, more preferably from 3 to 10 minutes.
Other liquid detergent ingredients may be introduced during step (ii).
Examples of such ingredients include nonionic surfactants, and low-
10 melting fatty acids which may also be neutralised in-situ, to form soaps.
The neutralisation step (ii) may typically take 2 to 12 minutes, and, as
indicated above, the gradual addition of the acid precursor (optionally plus
other liquid ingredients) may or may not be preceded by a separate step in
15 which water (optionally plus other liquid ingredients) is added to the mixer.
As indicated previously, the temperature of the powder mass in the
high-speed mixer/granulator should be maintained throughout step (ii) at
55C or below, preferably below 50C, more preferably below 47C and
20 desirably below 40C. A water jacket may be sufficient, for example, a jacket
supplied with water at 25C is generally adequate to achieve temperatures
below 47C; but in some cases it may be necessary to provide a cryogenic
unit to inject cooling liquid or gas, for example, liquid nitrogen, into the
mass of powder. If the temperature is allowed to rise, agglomeration and
1 33751 3
lump formation may occur.
A very important feature of the process of the invention is
granulation in the high-speed mixer/granulator. This will generally take
5 the form of a separate granulation step (iii) after addition of the acid
precursor and neutralisation are complete. If, however, addition of the
liquids takes place over a relatively long period, granulation can occur
before addition is complete, and then a separate granulation step (iii) may
be unnecessary. In this case, steps (ii) and (iii) of the process may be
10 regarded as having coalesced to form a single continuous step (ii)/(iii).
The granulation or densification process leads to a product of very
high bulk density. Granulation in the process of the invention requires the
presence of a liquid binder, but in an amount significantly lower than that
15 used when granulating a powder in conventional apparatus such as a pan
granulator: for example, from 3 to 8 wt% of the total composition,
especially about 5 wt%, as compared to 10-15 wt%. The binder is added prior
to granulation but after neutralisation is complete. It will generally
comprise water and/or a liquid detergent ingredient, for example, an
20 aqueous solution of a polycarboxylate polymer, or a nonionic surfactant, or
a mixture of any of these.
In calculating the amount of binder required, it is important to take
into account any free water already present in the composition and
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1 3375 1 3
releasable at the process temperature, generally about 30-50C. For example,
hydrated zeolite (which contains 27 moles of water per mole, or about 20
wt% of bound water) might be expected to release about 20 wt% of this (4
wt% of its total weight) at these temperatures; while sodium
5 tripolyphosphate hexahydrate would probably release little or no water.
It is believed that the total amount of free water that can be tolerated
in the whole process is limited and generally should not amount to more
than 8 wt% of the total composition, preferably not more than 4 wt%.
As with the water required for the neutralisation step (ii), sufficient
free moisture for granulation may be available from the powder mass itself,
and it may not be necessary to add a liquid binder.
The product of the granulation step (iii) is a particulate solid of high
bulk density - at least 650 g/litre, preferably at least 750 g/litre, and more
preferably at least 800 g/litre. As previously indicated, the particle size
distribution is generally such that at least 50 wt%, preferably at least 70 wt%
and more preferably at least 85 wt%, of particles are smaller than 1700
20 microns, and the level of fines is low. No further treatment has generally
been found to be necessary to remove either oversize particles or fines.
If desired, further ingredients may be admixed to the granulated
product of step (iii). For example, minor solid ingredients such as
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fluorescer and sodium carboxymethylcellulose may be added at this stage
rather than included in the initial solids mix.
Although the product generally has good flow properties, low
5 compressibility and little tendency towards caking, those powder properties
may be improved further and bulk density further increased by the
admixture of a builder salt or a finely divided particulate flow aid after
granulation is complete.
A preferred builder salt that may be postdosed is sodium
tripolyphosphate. This option is of especial interest for powders in which
the principal or sole builder is sodium carbonate.
The flow aids mentioned above are also suitable for addition at this
later stage in the process. Depending on the flow aid chosen, it may suitably
be added in an amount of from 0.2 to 12.0 wt%, based on the total product.
Suitable flow aids include crystalline and amorphous alkali metal
aluminosilicates having an average particle size within the range of from
0.1 to 20 microns, preferably from 1 to 10 microns. The crystalline material
(zeolite) is preferably added in an amount of from 3.0 to 12 0 wt%, more
preferably from 4.0 to 10.0 wt%, based on the total product. The amorphous
material, which is more weight-effective, is preferably added in an amount
of from 0.2 to 5.0 wt%, more preferably from 0.5 to 3.0 wt%, based on the
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total product. A suitable amorphous material is available commercially
from Crosfield Chemicals Ltd, Warrington, Cheshire, England, under the
trade mark Alusil. If desired, both crystalline and amorphous
aluminosilicates may be used, together or sequentially, as flow aids.
The other flow aids mentioned previously, namely, thermally
treated perlite, calcite, and diatomaceous earth, are also suitably used in
amounts of from 0.2 to 5.0 wt%, preferably from 0.5 to 3.0 wt%, based on the
total product.
Yet other flow aids suitable for use in the process of the invention
include precipitated silica, for example, Neosyl (Trade Mark), and
precipitated calcium silicate, for example, Microcal (Trade Mark), both
commercially available from Crosfield Chemicals Ltd.
A process which comprises admixing finely divided amorphous
sodium aluminosilicate to a dense granular detergent composition
containing surfactant and builder and prepared and/or densified in a high-
speed mixer/granulator is described and claimed in our copending
Canadian Patent Application No. 597,592 filed April 24,1989.
The product
As already indicated, the process of the invention produces a
granular high-bulk-density solid, containing surfactant and builder, and
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1 3375 1 3
having a bulk density of at least 650 g/litre and preferably at least 700 g/litre.
It is also characterised by an especially low particle porosity, preferably not
exceeding 0.25 and more preferably not exceeding 0.20, which distinguishes
it from even the densest powders prepared by spray-drying.
This final granulate may be used as a complete detergent
composition in its own right. Alternatively, it may be admixed with other
components or mixtures prepared separately, and may form a major or
minor part of a final product. Generally, any additional ingredients such as
10 enzymes, bleach and perfume that are not suitable for undergoing the
granulation process and the steps that precede it may be admixed to the
granulate to make a final product. The densified granulate may typically
constitute from 40 to 100 wt% of a final product.
In another embodiment of the invention, the densified granulate
prepared in accordance with the present invention is an "adjunct"
comprising a relatively high level of detergent-active material on an
inorganic carrier; and this may be admixed in a minor amount with other
ingredients to form a final product.
The process may with advantage be used to prepare detergent
compositions containing from 5 to 45 wt%, especially from 5 to 35 wt%, of
anionic surfactant, this anionic surfactant being derived wholly or in part
from the in-situ neutralisation reaction of step (ii).
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The process of the invention is of especial interest for the production
of detergent powders or components containing relatively high levels of
anionic surfactant, for example, 15 to 30 wt%, more especially 20 to 30 wt%,
5 but it is equally useful for the preparation of powders containing lower
levels of anionic surfactant.
The anionic surfactant prepared at least in part by in-situ
neutralisation may, for example, be selected from linear alkylbenzene
10 sulphonates, alpha-olefin sulphonates, internal olefin sulphonates, fatty
acid ester sulphonates and combinations thereof. The process of the
invention is especially useful for producing compositions containing
alkylbenzene sulphones, by in-situ neutralisation of the corresponding
alkylbenzene sulphonic acid.
Other anionic surfactants that may be present in compositions
prepared by the process of the invention include primary and secondary
alkyl sulphates, alkyl ether sulphates, and dialkyl sulphosuccinates.
Anionic surfactants are of course well known and the skilled reader will be
20 able to add to this list by reference to the standard textbooks on this subject.
If an especially high content of anionic surfactant in the final product
is desired, additional anionic surfactant, in salt form (generally aqueous
paste or solution) rather than in acid precursor form, may be added after
19
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granulation. In one preferred embodiment of the invention, the post-
added anionic surfactant is alpha-olefin sulphonate. The possible addition
of solid particulate anionic surfactant at an earlier stage in the process has
already been mentioned. Thus the process of the invention represents a
5 versatile route for incorporating high levels of anionic surfactant in
powders of high bulk density.
As previously indicated, nonionic surfactants may also be present.
These too are well known to those skilled in the art, and include primary
10 and secondary alcohol ethoxylates.
Other types of non-soap surfactant, for example, cationic,
zwitterionic, amphoteric or semipolar surfactants, may also be present if
desired. Many suitable detergent-active compounds are available and are
15 fully described in the literature, for example, in "Surface-Active Agents and
Detergents", Volumes I and II, by Schwartz, Perry and Berch.
If desired, soap may also be present, to provide foam control and
additional detergency and builder power.
Typically, detergent compositions produced by the process of the
invention may comprise from 10 to 35 wt% of anionic surfactant, from 1 to
10 wt% of nonionic surfactant, and from 0 to 5 wt% of fatty acid soap.
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1 3375 1 3
Typical products of the invention
The following are general, non-limiting examples of formulation
types that may readily be prepared by the process of the invention.
(1) Compositions comprising:
(a) from 5 to 45 wt% of anionic surfactant,
(b) from 20 to 70 wt% of inorganic builder salt comprising
crystalline or amorphous alkali metal aluminosilicate, sodium
tripolyphosphate, sodium carbonate, sodium silicate or any
combination thereof,
(c) from 0 to 20 wt% of filler and/or flow aid comprising
diatomaceous earth, silica, calcite, sodium sulphate, bentonite, kaolin
or any combination thereof,
and optionally other detergent ingredients to 100 wt%.
In particular:
(la) compositions containing sodium tripolyphosphate as the principal
builder, and also containing sodium carbonate as neutralising alkali:
(a) from 15 to 30 wt% of anionic surfactant,
(bl) from 10 to 60 wt% of sodium tripolyphosphate,
(b2) from 5 to 60 wt% of sodium carbonate,
(c) from 0 to 20 wt% of filler and/or flow aid comprising
diatomaceous earth, silica, calcite, sodium sulphate, bentonite, kaolin
or any combination thereof,
and optionally other detergent ingredients to 100 wt%; and
(lb) compositions containing sodium carbonate as the principal builder:
.,
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(a) from 15 to 30 wt% of anionic surfactant,
(b) from 20 to 70 wt% of sodium carbonate,
(c) from 0 to 20 wt% of filler and/or flow aid comprising
diatomaceous earth, silica, calcite, sodium sulphate, bentonite, kaolin
or any combination thereof,
and optionally other detergent ingredients to 100 wt%.
(2) Compositions containing crystalline or amorphous alkali metal
aluminosilicate, especially crystalline zeolite and more especially zeolite 4A,
as a detergency builder:
(a) from 5 to 35 wt% of non-soap detergent-active material
consisting at least partially of anionic surfactant,
(b) from 15 to 45 wt% (anhydrous basis) of crystalline or
amorphous alkali metal aluminosilicate,
and optionally other detergent ingredients, including any excess of the
neutralising agent for the anionic surfactant, to 100 wt%. The weight ratio
of (b) to (a) is preferably at least 0.9:1.
An especially preferred class of detergent compositions that may be
prepared by the process of the invention is described and claimed in our
copending Canadian Patent Application No. 597,593 filed April 24, 1989.
These compositions comprise:
(a) from 17 to 35 wt% of non-soap detergent-active material
consisting at least partially of anionic surfactant, and
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(b) from 28 to 45 wt% of crystalline or amorphous alkali metal
aluminosilicate,
the weight ratio of (b) to (a) being from 0.9:1 to 2.6:1, preferably from 1.2:1 to
1.8:1, and optionally other detergent ingredients to 100 wt%.
(3) Compositions as described in our copending European Patent
Application No. 89 304210.1 filed on 27 April 1989:
(a) from 12 to 70 wt% of non-soap detergent-active material, and
(b) at least 15 wt% of water-soluble crystalline inorganic salts,
including sodium tripolyphosphate and/or sodium carbonate,
the weight ratio of (b) to (a) being at least 0.4:1, preferably from 0.4:1 to 9:1
and more preferably from 0.4:1 to 5:1, and optionally other detergent
components to 100 wt%.
These compositions preferably contain a total of from 15 to 70 wt% of
water-soluble crystalline inorganic salts, which may comprise, for example,
sodium sulphate, sodium ortho- or pyrophosphate, or sodium meta- or
orthosilicate. Especially preferred compositions contain from 15 to 50 wt%,
more preferably from 20 to 40 wt%, of sodium tripolyphosphate.
As previously indicated, all these preferred classes of detergent
composition that may be prepared by the process of the invention may
contain conventional amounts of other conventional ingredients, for
example, bleaches, enzymes, lather boosters or lather controllers as
23
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appropriate, antiredeposition and antiincrustation agents, perfumes, dyes
and fluorescers. These may be incorporated in the product at any suitable
stage, and the skilled detergent formulator will have no difficulty in
5 deciding which ingredients are suitable for admixture in the high-speed
mixer/granulator, and which are not. The process of the invention has the
advantage over conventional spray-drying processes that no elevated
temperatures are involved, so fewer restrictions are imposed on the way in
which heat-sensitive ingredients such as bleaches and enzymes are
10 incorporated into the product.
The invention is further illustrated by the following non-limited
Examples, in which parts and percentages are by weight unless otherwise
stated.
EXAMPLES
Example 1
A 750 kg batch of high-bulk-density detergent powder having the
20 following nominal formulation was prepared using a Fukae (Trade Mark)
FS-1200 high-speed mixer/granulator:
24
1 3375 1 3
_
wt%
Linear alkylbenzene sulphonate 25.0
Nonionic surfactant 2.0
Soap 1.0
Zeolite 4A (anhydr.) ) (35.0
Water with zeolite ) (9.99
Sodium silicate 4.0
Acrylate/maleate copolymer 1.0
Sodium Sulphate 1.77
Fluorescer 0.18
Sodium carboxymethyl cellulose 0.9
Sodium carbonate 15.5
Total added water 2.0
Speckles 0.8
Enzyme 0.6
Perfume 0.25
100.00
20 The ratio of zeolite (anhydrous) to total non-soap surfactant in this
composition was 1.29:1.
The process was carried out as follows:
.~
1 3375 1 3
(i) Solid ingredients as specified below were dry-mixed in the Fukae
mixer for 1 minute, using a stirrer speed of 100 rpm and a cutter speed of
2000 rpm.
parts
Zeolite 4A (hydrated) 34.0
Sodium carbonate 19.53
Sodium carboxymethylcellulose 0.9
Sodium silicate 4.0
Acrylic/maleic copolymer 1.0
Fluorescer 0.9
Fatty acid 0.92
Total solids 61.25
15 ~ This amount of sodium carbonate represented a 4.9x excess over that
required for neutralisation of the alkylbenzene sulphonic acid (see
paragraph (ii) below).
(ii) Water (0.375 parts, = 0.61 wt% on total solids) was added, and the
20 mixer was operated at the same stirrer and cutter speeds for 1 minute 30
seconds. Linear alkylbenzene sulphonic acid (23.5 parts) was added over a
period of 5 minutes while the mixer was operated at a stirrer speed of 80
rpm and a cutter speed of 2000 rpm. The temperature was maintained
below 50C by means of a cooling jacket filled with water. Throughout this
26
.~.
1 3375 1 3
_
step, the reaction mixture remained in particulate form.
Total liquids 23.88
Solids as % of total 71.95
The liquid: solid ratio at the end of step (ii) was 0.39.
(iii) When neutralisation was complete, binder in the form of further
water (1.4 parts), and nonionic surfactant (2.0 parts), were added to the
10 mixer, which was then operated for 3 minutes at a stirrer speed of 100 rpm
and a cutter speed of 2000 rpm to effect granulation. The temperature was
maintained below 50C by means of a cooling jacket filled with water. The
product of this step was a granular solid.
Total liquids 27.28
Solids as % of total 69.19
The liquid: solid ratio at the end of step (iii) was 0.44.
20 (iv) Zeolite (a further 11 parts) was then added as a flow aid, while the
mixer was operated for 2 minutes at a stirrer speed of 90 rpm with the cutter
turned off.
The resulting powder was free-flowing, had a bulk density of 850
,~,~
1 3375 1 3
_
g/litre, and contained 73 wt% of particles <1700 microns. The particle
porosity was 0.15.
Coloured speckles of the same powder (0.8 parts) and enzyme
granules (0.6 parts) were mixed with the powder using a rolling drum, and
perfume (0.25 parts) were sprayed on, to give a fully formulated high-bulk-
density detergent powder having excellent powder properties.
Example 2
The procedure of Example 1 was repeated, with the difference that
the nonionic surfactant was added as a mixture with the acid, instead of
during step (iii). A similar powder was obtained.
Example 3
The procedure of Example 1 was repeated, with the difference that 5
parts of zeolite were added to the mixer during step (iii), after addition of
the binder but before granulation, and only 6 parts of zeolite were added as a
flow aid in step (iv). A similar powder was obtained.
Example 4
The procedure of Example 2 was repeated, with the difference that
half the anionic surfactant was added in step (i) as a powder (Marlon (Trade
Mark) A 390 ex Huls). A similar powder was obtained.
28
" ~3;'
1 3375 1 3
Example 5
This Example illustrates a procedure in which in-situ neutralisation
is followed by the addition of a spray-dried base powder, and the mix is
granulated together in the high-speed mixer/granulator.
A 750 kg batch of high-bulk-density detergent powder having the
following nominal formulation was prepared using a Fukae (Trade Mark)
FS-1200 high-speed mixer/granulator:
parts
Linear alkylbenzene sulphonate 25.0
Nonionic surfactant 2.0
Soap 1.0
Zeolite 4A (anhydr.) ) ( 35.0
Water with zeolite ) ( 10.0
Sodium silicate 4.0
Acrylate/maleate copolymer 1.0
Sodium Sulphate 1.8
Fluorescer 0.18
Sodium carboxymethyl cellulose 0.9
Sodium carbonate 15.5
96.4
The ratio of zeolite (anhydrous) to total non-soap surfactant in this
composition was 1.29:1.
29
''' X
, ~
- 1 3375 1 3
The process was carried out as follows:
(i) Solid ingredients as specified below were dry-mixed in the Fukae
mixer for 1 minute, using a stirrer speed of 100 rpm and a cutter speed of
2000 rpm.
Zeolite 4A (hydrated) 126
Sodium carbonate 93.1*
Sodium carboxymethylcellulose 3.4
Sodium silicate 15.2
Acrylic/maleic copolymer 3.8
Fatty acid 3.5
Fluorescer 0.7
Total solids 245.7
~5.98x excess over amount required for neutralisation.
(ii) Water (3 kg, = 1.22 wt% on total solids) was added, and the mixer was
operated at a stirrer speed of 60 rpm and a cutter speed of 2000 rpm for 1
minute. The following liquid mix was then added over a period of 3
20 minutes while the mixer was operated at the same stirrer and cutter speeds:
Linear alkylbenzene sulphonic acid 89 1
Nonionic surfactant 11.4
Total liquids (including water) 103.5
1 3375 1 3
The solids therefore represented 70.4 wt% of the liquids/solids mix during
the neutralisation step.
5 The liquid: solid ratio at the end of the neutralisation step was 0.42. The
temperature was maintained below 50C by means of a cooling jacket filled
with water. Throughout this step, the reaction mixture remained in
particulate form.
10 (iii) When neutralisation was complete, a spray-dried base powder (336
kg) of the following formulation was added to the mixer:
parts
Linear alkylbenzene sulphonate 25.0
Nonionic surfactant 1.0
Soap 1.0
Zeolite 4A (anhydr.) ) ( 35.0
Water with zeolite ) ( 10.0
Sodium silicate 4.0
Acrylate/maleate copolymer 1.0
Sodium sulphate 1.8
Fluorescer 0.18
Sodium carboxymethyl cellulose 0.9
Sodium carbonate 10.5
Water 3.0
~,
1337513
and the whole mix granulated for 4 minutes at a stirrer speed of 80 rpm and
a cutter speed of 2000 rpm. The spray-dried powder contained sufficient free
water, in addition to that added during step (ii), that no further addition of
5 water as binder was necessary.
(iv) Zeolite (a further 60 kg) was then added as a flow aid, while the mixer
was operated for 1 minute at a shrrer speed of 80 rpm with the cutter turned
off.
The resulting powder was free-flowing, had a bulk density of
891 g/litre, and contained 80 wt% of particles <1700 microns.
Examples 6 and 7
This pair of Examples illustrates the benefit of cooling with liquid
nitrogen during the neutralisation step (ii).
Two 750 kg batches (Examples 6 and 7) of high-bulk-density detergent
powder having the nominal formulation given in Example 5 was prepared
20 using the Fukae FS-1200 high-speed mixer/granulator. The process was
carried out as follows:
(i) Solid ingredients as specified below were dry-mixed in the Fukae
mixer for 1 minute, using a stirrer speed of 100 rpm and a cutter speed of
1 33 75 1 3
2000 rpm.
Zeolite 4A (hydrated) 285
Sodium carbonate 148
Sodium carboxymethylcellulose 6.8
Sodium silicate 30.4
Acrylic/maleic copolymer 7.6
Fatty acid 7.0
Total solids 484.8
(ii) Water (6 kg, = 1.24 wt% on total solids) was added, and the mixer was
operated at a stirrer speed of 75 rpm and a cutter speed of 2000 rpm for 1
minute. The following liquid mix was then added over 5 minutes while
15 the mixer was operated at the same stirrer and cutter speeds:
Linear alkylbenzene sulphonic acid 178
Nonionic surfactant 15
Total liquids (including water) 199
Solids as % of total 70.9
Liquid: solid ratio 0 41
After addition of the liquids was complete the mixer speeds were increased
to 100 rpm/2000 rpm for 2 minutes. For Example 6, the temperature was
1 3375 1 3
_
maintained below 35C throughout the neutralisation step by spraying
liquid nitrogen into the powder. For Example 7, the liquid nitrogen cooling
was omitted, and the temperature rose to 52C. In both Examples, the
reaction mixture remained in particulate form throughout the
neutralisation step.
(iii) When neutralisation was complete, binder in the form of further
water (6 kg) was added to the mixer at stirrer/cutter speeds of 80 rpm/2000
rpm, and the mixer was then operated for 3 minutes at the same stirrer and
cutter speeds to effect granulation.
(iv) Zeolite (a further 57 kg) as a flow aid, and fluorescer (1.4 kg) were
then added, while the mixer was operated for 1 minute at a stirrer speed of
80 rpm with the cutter turned off.
The powder of Example 6 was free-flowing, had a bulk density of 821
g/litre, and contained 81 wt% of particles <1700 microns.
The powder of Example 7 was a product of similar bulk density but
containing only 69 wt% of particles <1700 microns.
Example 8
A 20 kg batch of high-bulk-density detergent powder having the
following nominal formulation was prepared using a Fukae FS-30 high-
34
~ 3375 1 3
-
speed mixer/granulator:
wt%
Linear alkylbenzene sulphonate 23.34
Nonionic surfactant 1.5
Soap 07
Zeolite 4A (anhydr.) ( 35.83
Water with zeolite ( 10.17
Sodium silicate 4.0
Acrylate/maleate copolymer 2.0
Sodium sulphate 1.72
Fluorescer 0.18
Sodium carboxymethyl cellulose 0.9
Sodium carbonate 15.0
Added water 2.0
Speckles 0.8
Enzyme 0.61
Perfume 0.25
Flow aid 1.0
100.00
The ratio of zeolite (anhydrous) to total non-soap surfa~tant in this
composition was 1.44:1.
The process was carried out as follows:
- 1 3375 1 3
(i) Solid ingredients as specified below were dry-mixed in the Fukae
mixer for 1 minute, using a stirrer speed of 300 rpm and a cutter speed of
3000 rpm.
parts
Zeolite 4A (hydrated) 38.5
Sodium carbonate 18.72
Sodium carboxymethylcellulose 0.9
Sodium silicate 4.0
Total solids 62.12
This amount of sodium carbonate represented an approximately 5x excess
over the amount required for neutralisation of the alkylbenzene sulphonic
acid and fatty acid (see paragraph (ii) below): the excess corresponds to the
15 15.0 wt% present in the final formulation to provide alkalinity.
(ii) Water (0.375 parts, = 0.61 wt% on total solids) was added, and the
mixer was operated at a stirrer speed of 100 rpm and a cutter speed of 3000
rpm for 1 minute 30 seconds. The following liquid mixture was added over
20 a period of 5 minutes while the mixer was in operation at the same stirrer
and cutter speeds:
36
1 3 3 7 5 1 3
parts
Linear alkylbenzene sulphonic acid 21.85
Fatty acid 0.65
Nonionic surfactant 1.5
Total liquids 24.00
Solids as % of total 72.13
Liquid: solid ratio 0.39
10 The temperature was maintained below 50C by means of a cooling jacket
filled with water. Throughout this step, the reaction mixture remained in
particulate form.
(iii) When neutralisation was complete, the following binder mixer was
added:
parts
Water 1.0
Acrylic/maleic copolymer 2.0
Fluorescer 0.9
Total liquids 27.9
Solids as % of total 69 0
Liquid: solid ratio 0.45
The mixer was then operated for 3 minutes at a stirrer speed of 300 rpm and
a cutter speed of 3000 rpm to effect granulation. The temperature was
37
~;
1 337~13
maintained below 50C by means of a cooling jacket filled with water. The
product of this step was a granular solid.
5 (iv) 7.5 parts of zeolite, and 1 part of amorphous sodium aluminosilicate
(Alusil (Trade Mark) ex Crosfield Chemicals Ltd, 1 part) were then added as
a flow aid, while the mixer was operated for 2 minutes at a stirrer speed of
90 rpm with the cutter turned off.
The resulting powder was free-flowing, had a bulk density of 830
g/litre, and contained 85 wt% of particles ~1700 microns.
Coloured speckles of the same powder (0.8 parts) and enzyme
granules (0.61 parts) were mixed with the powder using a rolling drum, and
15 perfume (0.25 parts) were sprayed on, to give a fully formulated high-bulk-
density detergent powder having excellent powder properties.
Example 9
A 20 kg batch of high-bulk-density detergent powder built with
20 sodium tripolyphosphate and sodium carbonate and having the following
nominal formulation was prepared using a Fukae FS-30 high-speed
mixer/granulator:
38
1 3375 1 3
parts
Linear alkylbenzene sulphonate 32.0
Sodium tripolyphosphate 22.0
Sodium carbonate 40.0
Added water 2.0
Minor ingredients 0.7
Alusil flow aid 2.0
98.70
The ratio of crystalline water-soluble inorganic salts to total non-soap
surfactant in this composition was 1.9: 1.
15 In this formulation sodium carbonate was present as a major part of the
building system. The sodium carbonate introduced during step (i) (see
below) amounted to an approximately 8x excess over the amount required
for neutralisation of the alkylbenzene sulphonic acid (see paragraph (ii)
below).
The process was carried out as follows:
(i) The solid ingredients were dry-mixed in the Fukae mixer for 1
minute, using a stirrer speed of 300 rpm and a cutter speed of 3000 rpm:
39
- 1337513
parts
Sodium carbonate 44.92
Sodium tripolyphosphate 22.0
Dry minor ingredients 0.7
Total solids 67.62
(ii) Water (2 parts) was added, and the mixer was operated at a stirrer
speed of 100 rpm and a cutter speed of 3000 rpm for 1 minute. The linear
alkylbenzene sulphonic acid (29.96 parts) was added over a period of 1
minute while the mixer was in operation at the same stirrer and cutter
speeds. The temperature was maintained below 50C by means of a cooling
jacket filled with water. Throughout this step, the reaction mixture
15 remained in particulate form.
Total liquids 31.96
Solids as % of total 67.90
Liquid: solid ratio 0.47
20 (iii) When neutralisation was complete, binder in the form of further
water (4.0 parts) was added to the mixer, while it was operated for 1 minute
at a stirrer speed of 100 rpm and a cutter speed of 3000 rpm. The mixer was
which was then operated for 4 minutes at a stirrer speed of 300 rpm and a
cutter speed of 3000 rpm to effect granulation. The temperature was
_-
1 3375 1 3
-
maintained below 50C by means of a cooling jacket filled with water. The
product of this step was a granular solid.
total liquids 35.96
Solids as % of total 65.28
Liquid: solid ratio 0.53
(iv) Alusil (2 parts) was then added as a flow aid, while the mixer was
operated for 1 minute at a stirrer speed of 90 rpm with the cutter turned off.
The resulting detergent powder was free-flowing, had a bulk density
of 875 g/litre, and contained 75 wt% of particles <1700 microns. Powder
properties were excellent: dynamic flow rate was 133 ml/s and
compressibility was 2% v/v.
Example 10
A 750 kg batch of high-bulk-density detergent powder built with
sodium tripolyphosphate and sodium carbonate and having the following
nominal formulation was prepared using a Fukae FS-1200 high-speed
mixer/granulator:
41
~7~'
~'
1 3375 ~ 3
wt%
Linear alkylbenzene sulphonate 25.0
Soap 2.0
Sodium tripolyphosphate 38.0
Sodium silicate 5.0
Sodium carbonate 18.2
Sodium sulphate 6.6
Fluorescer 0.2
Alusil flow aid 3.0
Addedwater 2.0
100.00
The ratio of crystalline water-soluble inorganic salts to total non-soap
surfactant in this composition was 2.5:1.
The process was carried out as follows:
(i) The solid ingredients were dry-mixed in the Fukae mixer for 1
minute, using a stirrer speed of 100 rpm and a cutter speed of 1200 rpm.
Sodium carbonate 22.04
Sodium tripolyphosphate 38.0
Sodium sulphate 6.6
Dry minor ingredients 0.2
Total solids 66.84
42
~;,
1 3375 1 3
(ii)/(iii) Water and alkylbenzenesulphonic acid were added over a
period of 10 minutes while the mixer was operated at a stirrer speed of 35
rpm and a cutter speed of 1200 rpm. The temperature was maintained at
5 about 45C by means of a cooling jacket filled with water. Because of the
rather slow addition of the acid, it was found that granulation had occurred
as soon as acid addition was complete. Thus no separate granulation step
was requlred.
Water 0.8
Alkylbenzene sulphonic acid 23.4
Total liquids 24.2
Solids as % of total 73.41
Liquid: solid ratio 0.36
(iv) Alusil was added as a flow aid, while the mixer was operated for 1.5
minutes at a stirrer speed of 80 rpm and a cutter speed of 1200 rpm.
The resulting detergent powder was free-flowing, had the extremely
high bulk density of 1050 g/litre, and contained about 70 wt% of particles
<1700 microns. Dynamic flow rate was 71 ml/s and compressibility was
4.7% v/v.
43
t
,~.~.
- 1 3375 1 3
Example 11
A 60 kg batch of high-bulk-density detergent powder having the
following nominal formulation was prepared using a Sapphire (Trade
Mark) RMG-100 high-speed mixer/granulator:
wt%
Linear alkylbenzene sulphonate 29.0
Sodium tripolyphosphate 35.0
Sodium carbonate 20.0
Flow aid (Dicamol 424)1 5.0
Sodium carboxymethylcellulose 1.5
Fluorescer (Photine C) 0.3
Blue dye (phthalocyanine) 0.1
Perfume 0.1
Flow aid (Dicamol 424)2 1.0
Water3 5.0
Salts etc to 100.0
Added before neutralisation (see below)
2 Added after neutralisation (see below)
3 Added water about 1-1.5 wt%; the rest is from the raw
materials and generated by the neutralisation reaction.
The process was carried out as follows:
44
X-
1 3375 1 3
(i) Solid ingredients as specified below were dry-mixed in the Sapphire
mixer for 1 minute, using a stirrer speed of 75 rpm and a cutter speed of
2880 rpm.
parts
Sodium tripolyphosphate 35.0
Sodium carbonate 25.76
Flow aid (Dicamol 424) 5.0
This amount of sodium carbonate represented a 4.47x excess over that
required for neutralisation of the alkylbenzene sulphonic acid (see
10 paragraph (ii) below).
(ii) A liquids premix was prepared by mixing 0.1 parts of phthalocyanine
blue dye and 1.0 part water with a Silverson mixer, then mixing the
resulting dye dispersion into 29.19 parts of alkylbenzene sulphonic acid of
15 93 wt% purity, also with the Silverson mixer.
The liquids premix was then added to the solids mix in the Sapphire
mixer at a liquid to solid ratio of 0.47 over a period of 5 minutes while the
mixer was operated at a stirrer speed of 75 rpm and a cutter speed of 2880
20 rpm. The temperature was maintained below 50C by means of a cooling
jacket filled and circulated with water at 25C. Throughout this step, the
reaction mixture remained in particulate form.
(iii) When neutralisation was complete, the cutter speed was reduced to
,,~f
1 33 75 1 3
1440 rpm while the stirrer speed remained at 75 rpm, and minor solids
(sodium carboxymethyl cellulose, fluorescer) were added over a l-minute
period, together with further flow aid (Dicamol 424). The resulting mix was
granulated for a further 1 minute at a stirrer speed of 75 rpm and a cutter
5 speed of 2880 rpm. The material was then discharged over a l-minute
period with the cutter turned off and the stirrer running at 75 rpm.
The resulting powder was free-flowing, homogeneously blue
coloured, had a bulk density of 800 g/litre, and contained 90 wt% of
particles <1700 microns. The mean particle size was 539 microns. Dynamic
flow rate was 81.1 ml/s, and compressibility was 9.2% v/v.
The powder had a rapid rate of dissolution comparable with the best
high-bulk-density powders presently on the market:
15Time (seconds) Dissolution (wt%)
0 64.9
78.5
86.1
89.5
A sample was examined by scanning electron micrography and was
found to have a much more porous surface than a similar powder made
without the addition of the flow aid Dicamol 424 to the initial solids mix.
46
1 3375 1 3
Examples 12 to 14
These Examples illustrate the benefits of adding a flow aid (in this
case calcite, Forcal (Trade Mark) U) during the initial stage - step (i) - of the
process.
Three 60 kg batches of the high-bulk-density detergent powder
having the following nominal formulation was prepared using a Sapphire
(Trade Mark) RMG-100 high-speed mixer/granulator:
wt%
Linear alkylbenzene sulphonate 29.0
Sodium tripolyphosphate 35.0
Sodium carbonate 20.0
Flow aid see below
Sodium carboxymethylcellulose 1.5
Fluorescer (Photine C) 0.3
Blue dye (phthalocyanine) 0.1
Perfume 0.1
Water 5.0
Salts etc to 100.0
The powders were prepared generally as described in Example 1, with
the following differences relating to the addition of flow aid.
Before After
neutralisation neutralisation
Example 12: 5 parts Forcal U 2 parts Dicamol 424
Example 13: - 5 parts Forcal U after part
neutralisation; 1.5 parts
47
,.,
1 3375 1 3
Dicamol 424 after
neutralisation complete
Example 14: - 5parts ForcalU
1 part Dicamol 424
The liquid to solid ratios at the end of the neutralisation step in these
Examples were therefore 0.55, 0.57 and 0.60 respectively.
All three powders were free-flowing, homogeneously blue coloured,
10 and had bulk densities greater than 700 g/litre. Other powder properties
were as follows:
13 14
Yield <1700 microns (wt%) 90.3 81.2 83.1
Average particle size (llm) 607 709 699
Dynamic flow rate (ml/s) 120 120 125
Bulk density (g/l) 765 780 800
Dissolution (wt%):
after 10 sec 56.5 33.8 27.7
after30 sec 71.4 49.7 47.8
These results show that the sequence of addition used in Example 12
gave a powder with a smaller average particle size and a supierior rate of
dissolution.
48
1 337~ 1 ~
Examples 15 to 19
These Examples show the effects of different flow aids added before
5 neutralisation.
60kg batches of powder were prepared by the general procedure used
in previous Examples, but using different amounts of different flow aid as
follows:
Example Liquid: Flow aid in Flow aid in
solid step (i) step (ii)
0.55 zeolite (5 parts) Dicamol (1 part)
16 0.49 Dicamol (5 parts)
17 0.53 Forcal U (5 parts) Dicamol (2 parts)
18 0.51 Filtroseem (5 pts) Dicamol (1.5 pts)
19 0.56 Dicamol (5 parts) Dicamol (1 part)
Powder properties are shown in the following table. It will be seen
that Example 19 gave the best combination of properties.
49
~,
1 3375 1 3
-
16 17
Bulk Density (g/litre) 730 736 720
Yield <1700 microns (wt%) 82.5 90.0 85.0
Average particle size (,um) 723 539 640
Dynamic flow rate (ml/s) 110 81 100
Compressibility (%v/v) 10.5 10.0 15.8
Dissolution (wt%):
after 15sec 38.3 64.9 43.9
after30 sec 58.2 78.5 63.7
18 19
Bulk density (g/litre) 751 736
Yield <1700 microns (wt%) 85.6 86.3
Average particle size (~m) 536 560
Dynamic flow rate (ml/s) 115 115
Compressibility (%v/v) 11.8 11.0
Dissolution (wt%):
after 15 sec 55.4 58.8
after30 sec 74.6 78.2
Examples 20 to 22
The general procedure of earlier Examples was repeated, but to give
powders containing a mixed surfactant system of alkylbenzene sulphonate
(prepared by neutralisation) and alpha-olefin sulphonate (post-added as 4
1 3375 1 3
wt% aqueous solution). The formulations were as follows:
21 22
Alkylbenzene sulphonate26.1 26.1 22.7
Olefin sulphonate 2.9 2.9 5.0
Sodium tripolyphosphate35.0 35.0 32.0
Sodium carbonate 20.0 20.0 20.0
Flow aid (Dicamol)l 5.0 5.0
Flow aid (calcite)l - - 2.0
SCMC 1.5 1.5 1.5
Fluorescer 0.3 0.3 0.3
Perfume 0.1 0.1 0.1
Flow aid (Dicamol)2 1.0 0.5 2.0
Salts, water etc to 100.00 100.00 100.00
Added before neutralisation
2 Added after neutralisation
The powder properties of Examples 20 and 21, as shown in the
20 following table, were not significantly different from those of Example 19.
The powder of Example 22 had a higher bulk density but inferior flow
properties.
V~ 51
1 33 75 1 3
21 22
Bulk density (g/litre) 780 780 830
Yield <1700 microns (wt%) 87.1 84.3 89.8
Average particle size (,um) 527 578 443
Dynamic flow rate (ml/s) 100 103 67
Compressibility (%v/v) 12.6 13.8
Dissolution (wt%):
after 15sec 58.9 48.5
after30 sec 75.7 68.3 77.7
Examples 23 to 25
The general procedure of earlier Examples was used to prepare
sodium tripolyphosphate-built detergent powders having the following
formulations:
23 24 25
Alkylbenzene sulphonate 29.8 25.1 24.3
Sodium tripolyphosphate 52.0 20.0 35.0
Sodium carbonate 8.0 45.0 25.0
Flow aid (calcite)1 - 2.0 5.0
SCMC 1.5 1.5 1.5
Fluorescer (Photine C) 0.3 0.3 0.3
Perfume 0.1 0.1 0.1
Flow aid (Dicamol 424)2 - 2.0 2.0
Water, salts etc to 100.0 100.0 100.0
Liquid: solid ratio 0.60 0.42 0.45
Added before neutralisation
2 Added after neutralisation
52
~ 1 3375 1 3
Powder properties were as follows:
23 24 25
Bulk density (g/litre) 800 800 830
Yield <1700 microns (wt%) 84.093.3 89.4
Dynamic flow rate (ml/s) 85 80 120
Average particle size (~lm) 742 455
Examples 26 to 29
The general procedure of earlier Examples was used to produce 60 kg
batches of sodium carbonate-built powders to the formulations show below.
In Examples 27 and 28, the alpha-olefin sulphonate was post-added in the
form of 70 wt% paste; in Example 29 it was added as 40 wt% solution, after
15 neutralisation but before the addition of the greater part of the calcite.
26
Linear alkylbenzene sulphonate 19.0 18.9
Alpha-olefin sulphonate - 5.0
Sodium carbonate 67.0 61.0
Flow aid (calcite) 4.0 4.0
SCMC 1.5 1.5
Fluorescer (Photine C) 0.2 0.2
Perfume 0.1 0.1
Flow aid (Dicamol 424) 2.0 2.0
Water, salts etc to 100.0 100.0
Liquid: solid ratio 0.36 0.50
~ 1 3375 1 3
28 29
Linear alkylbenzene sulphonate 20.7 22.5
Alpha-olefin sulphonate 5.0 2.5
Sodium carbonate 62.0 58.0
Flow aid (calcite) 4.0 5.0
SCMC 1.5 1.5
Fluorescer (Photine C) 0.2 0.2
Perfume 0.1 0.1
Flow aid (Dicamol 424) 2.0 2.0
Water, salts etc to 100.0 100.0
Liquid: solid ratio 0.50 0.44
Powder properties were as follows:
26 27
Bulk density (g/litre) 800 800
Yield <1700 microns (wt%) 93.7 95.7
Dynamic flow rate (ml/s) 37.5* 70.0
Average particle size (!lm) - 507
* It was found that the poor flow properties of the powder of Example 16
20 could be substantially improved by postdosing a small amount of sodium
tripolyphosphate:
7.5 wt% STP improved the dynamic flow rate to 55.5 ml/s;
15.0 wt% STP improved the dynamic flow rate to 60.0 ml/s.
54
,,,~
1 3375 1 3
28 29
Bulk density (g/litre) 880 796
Yield <1700 microns (wt%) 92.8 90.0
Dynamic flow rate (ml/s) 75 92
Compressibility (% v/v) - 13.2
Average particle size (~lm) 491 268
'X.
.
