[0001] The present invention relates to a dispensing device for dispensing concentrated
particulate detergent compositions in e.g. a washing machine.
[0002] Particulate detergent compositions with improved environmental profiles could, in
theory, be designed by eliminating all components from the composition that provide
limited, or no, cleaning action. Such compact products would also reduce packaging
requirements. One problem with compact or concentrated compositions is that consumers
must dose accurately however they tend to use more of the composition than is recommended,
probably due to their familiarity with the previous less concentrated variants. Studies
have shown that consumers tend to overdose concentrated compositions and this is bad
for their pocket and bad for the environment. Dosing measures are frequently provided,
and ignored.
[0003] EP 0903405 discloses a packaged product in the form of a blister packaging comprising a plurality
of individual reservoirs, each containing a dose of a concentrated particulate laundry
composition.
[0004] It is an object of the present invention to provide a packaged particulate concentrated
detergent composition wherein the dosage is more controllable by the consumer.
[0005] Accordingly, in a first aspect, the present invention provides a packaged product
comprising a package comprising a plurality of individual reservoirs, each of the
reservoirs containing a predetermined dose of a concentrated particulate laundry wherein
at least 70 % by number of the particles of the composition comprising a high-surfactant
hard core and a coating and wherein all the particles are non spherical and at least
0.2 mm in diameter.
[0006] With this arrangement, the consumer has pre-measured doses so there is no need to
measure and the tendency to overdose is eliminated or at least reduced. At the same
time, coated particulate concentrated detergent compositions of the invention, with
large non-spherical similarly shaped and sized particles provide a slow, steady and
predictable flow from the small reservoirs and eliminates or at least minimises product
residue in the reservoirs. With conventional powders, the inner surfaces of the reservoir
become coated with a fine dusting, which would affect the transparency. For this reason,
traditionally powders are mostly sold in opaque cartons or pouches. However, the large
hard-coated particles of the invention do not form a film over the reservoir surface.
The coating reduces the stickiness of the hygroscopic surfactant core to a point where
the particles are free flowing across a surface. This together with the particle size
means that any composition left in the package after tipping/pouring etc. are present
in minor and localised amounts. A gentle tap releases them from the surface. Even
liquid formulations do not provide this advantage - liquids coat then inner surfaces
of reservoirs and so leave residue.
[0007] The package is sufficiently rigid in material and/or construction such that a portion
e.g. the base or a side wall, can be tapped to move the particles from the reservoir/s.
Such tapping creates audible feedback to the user to guide them as to the movement
of the particles.
[0008] The large format of the particles reduces the impact of stickiness as the number
of potential bridging points is reduced and the force exerted by each particle when
it attempts to move is much greater than a conventional powder due to the mass of
each particle being about 25 times greater. Thus even under slightly damp conditions,
as may be experienced in a laundry room, the particles remain more reliably slow flowing.
[0009] The package may comprise a tray of individual recesses, each recess providing an
individual reservoir covered by a lid. There may be a common lid for two or more recesses.
Preferably the package comprises a blister pack.
[0010] The blister pack preferably comprises a planar sheet of plastic provided with "blisters"
or concave protrusions configured in various patterns, e.g. rows and columns. Each
of the blisters or concave protrusions is sized to receive a predetermined dose of
the composition. Preferably, the blister pack further comprises at least one backing
layer is fastened to the solid receiving side of the blister pack. This layer is a
low strength retaining layer. This low strength retaining layer stretches across the
backs of the blisters and retains the doses individually sealed within each of the
blisters. Preferably the blister pack is mounted with the low strength retaining layer
facing down.
[0011] The packaged product may comprise a dispenser comprising a rigid support frame on
which is mounted said pack, whereby manual force on a selected reservoir ejects that
dose from the package.
[0012] With this arrangement, the precise doses of the composition can be dispensed highly
efficiently. The dispenser may be installed in a machine e.g. washing machine drawer
so manual force on a selected dose ejects this dose from the blister pack directly
into the drawer or drawer compartment if compartments are provided. The blister pack
and dispenser are preferably water insoluble.
[0013] The rigid support frame preferably comprises at least one wall with one or more apertures
therein such that water flow is minimally restricted. Alternatively or additionally
the frame may comprise a mesh structure and/or support pillars optionally with cross
ties or the like. The structure should also have smooth contours and generally convex
rather than concave surface configuration/ patterning such that water and/or laundry
composition cannot become trapped.
[0014] The dispensing device is preferably water insoluble so it can be left in the machine.
Alternatively, the device may be installed for use e.g. on the upper edges of the
drawer, so that the dose can be dosed directly into the drawer, and then removed prior
to the washing operation.
[0015] By "rigid" is meant here that the frame has sufficient rigidity to withstand the
manual force required to break the blister pack. Some elasticity may be allowed, at
higher forces than that required to break the blister open, and indeed may even be
desirable. For example the walls may be flexible (or flexibly attached to the rest
of the frame), so that the will flex against the drawer sides. With this feature,
during fitting these can be forced to flex inward and then once in place, and they
are released so as to urge against the sides of the drawer, thereby preventing movement
of the dispensing device whilst in place in the drawer.
[0016] Preferably the blister pack is mounted removably. This way it may be replaced when
required, e.g. all the doses have been used, or for an alternative blister pack with
different composition. To negate the need for frequent changes, the blister pack may
contain unit doses with different compositions. Preferably the rigid frame and blister
pack comprise an engaging mechanism for secure mounting. Advantageously, this mechanism
comprises mutually interengaging projections and recesses on the frame and pack. The
rigid support frame may comprise recesses corresponding with the shape of the blisters.
For example, if the blisters are circular, there may be annular or semi-circular recesses
along the support frame. These can engage with the blisters and provide support and/or
secure positioning of the blister pack. Preferably the rigid frame comprises a wall
or walls having supporting upper edges which correspond to an outer perimeter of the
blister pack so that it is supported along its perimeter. Further walls can be provided
to provide further support between the unit doses, these further walls preferably
corresponding with areas of the blister pack between the unit doses. The support frame
may comprise an upper supporting edge which is inclined with respect to the base,
whereby the mounted blister pack is also inclined. With this arrangement, the blister
pack may be better viewed by the user.
[0017] In a third aspect the invention provides a method of washing fabrics within a washing
machine, with the package of the first aspect of the invention, the method comprising
the step of manually pressing on a dose in one of the reservoirs to eject the dose
from the blister pack.
[0018] The above method preferably comprises the earlier step of mounting the package e.g.
blister pack onto the rigid support frame. The method may comprise the step of installing
the rigid support frame, before or after installing the package thereon, into the
drawer of a washing machine, whereby the step of manually pressing externally of a
reservoir in the package, ejects the dose from the reservoir into the drawer. The
method may optionally comprise the step of removing the rigid support frame from the
drawer before washing or it may comprise the step of beginning the wash process with
the rigid support frame installed in the drawer, with or without the package. Where
the blister pack is to remain in place mounted on the rigid support frame during a
wash it should comprise water soluble materials or at least an outer water soluble
barrier.
[0019] The or each reservoir comprises a transparent portion. This allows the consumer to
see when all the dose has been preferably the or each transparent portion comprises
at least a part of the base of the reservoir, such that the composition contained
within is visible when viewed looking at the base. This is advantageous for e.g. blister
packs which tend to be used base upwards.
[0020] Preferably the or each transparent portion comprises more than 50%, more preferably
more than 60%, and most preferably more than 75% of the surface area of the reservoir.
[0021] In so far as the packaging is concerned, "transparent" means that its light transmittance
is greater than 25% at wavelength of about 410-800 nm. The or each transparent portion
according to the invention preferably has a transmittance of more than 25%, more preferably
more than 30%, more preferably more than 40%, more preferably more than 50% in the
visible part of the spectrum (approx. 410-800 nm).
[0022] Alternatively, absorbency of transparent layer may be measured as less than 0.6 (approximately
equivalent to 25% transmitting) or by having transmittance greater than 25% wherein
% transmittance equals:

[0023] Conversely, absorbency of the opaque layer may be measured as more than 0.6.
[0024] For purposes of the invention, as long as one wavelength in the visible light range
has greater than 25% transmittance, the container is considered to be transparent.
Alternatively, absorbency of bottle may be measured as less than 0.6 (approximately
equivalent to 25% transmitting) or by having transmittance greater than 25% wherein
% transmittance equals: 1 10
absorbency x 100% and corresponding absorbency levels for the remaining preferred levels above.
[0025] Suitable materials for the package include, but are not limited to: polypropylene
(PP), polyethylene (PE), polycarbonate (PC), polyamides (PA) and/or polyethylene terephthalate
(PETE), polyvinylchloride (PVC); and polystyrene (PS). The reservoirs may formed by
moulding e.g. blow moulding from a preform or by thermoforming or by injection moulding.
[0026] Preferably the packaged particles are substantially the same shape and size as one
another.
[0027] Preferably the composition comprises greater than 40 wt% detergent surfactant. Preferably,
at least 70% by number of the particles comprise a core, comprising mainly surfactant,
and around the core a water soluble coating comprising 15 to 45 wt% of the coated
particle.
[0028] Preferably each coated particle has perpendicular dimensions x, y and z, wherein
x is from 0.2 to 2 mm, y is from 2.5 to 8mm (preferably 3 to 8 mm), and z is from
2.5 to 8 mm (preferably 3 to 8 mm) and preferably the packaged particles are substantially
the same shape and size as one another.
[0029] Preferably the coating comprises at least 10 wt% of a water soluble salt. More preferably
the water soluble salt comprises an inorganic salt. Most preferably it comprises sodium
carbonate. The coating may further comprise a minor amount of sodium carboxy methyl
cellulose (SCMC), sodium silicate, water soluble fluorescer, water soluble or dispersible
shading dye, pigment, coloured dye and mixtures thereof.
[0030] The amount of coating on each coated particle is preferably 20 to 35 % by weight
of the particle.
[0031] The number percentage of the packaged composition of particles comprising the core
and coating is preferably at least 85%.
[0032] The coated particles preferably comprise from 0.001 to 3 wt% perfume.
[0033] The core of the coated particles preferably comprises less than 5 wt%, even more
preferably less than 2.5 wt% inorganic materials.
[0034] The particles are desirably oblate spheroids with diameter (y and z) of 3 to 6 mm
and thickness (x) of 1 to 2 mm.
[0035] At least some, and preferably a major portion by number of the particles may be coloured
other than white, as this makes it easier to see them to determine that the required
dose level has been reached. Multicoloured, e.g. some blue and some white, particles
have been found to provide even higher visual definition for the optimum control of
dose. Colour may be imparted by dye, pigment or mixtures thereof.
MANUFACTURE OF THE PARTICLES
[0036] A preferred manufacturing process is set forth in
PCT/EP2010/055256. It comprises blending surfactants together and then drying them to a low moisture
content of less than 1 %. Scraped film devices may be used. A preferred form of scraped
film device is a wiped film evaporator. One such suitable wiped film evaporator is
the "Dryex system" based on a wiped film evaporator available from Ballestra S.p.A..
Alternative drying equipment includes tube-type driers, such as a Chemithon Turbo
Tube® drier, and soap driers. The hot material exiting the scraped film drier is subsequently
cooled and broken up into suitable sized pieces to feed to the extruder. Simultaneous
cooling and breaking into flakes may conveniently be carried out using a chill roll.
If the flakes from the chill roll are not suitable for direct feed to the extruder
then they can be milled in a milling apparatus and /or they can be blended with other
liquid or solid ingredients in a blending and milling apparatus, such as a ribbon
mill. Such milled or blended material is desirably of particle size 1 mm or less for
feeding to the extruder.
[0037] It is particularly advantageous to add a milling aid at this point in the process.
Particulate material with a mean particle size of 10 nm to 10 µm is preferred for
use as a milling aid. Among such materials, there may be mentioned, by way of example:
aerosil®, alusil®, and microsil®.
Extruding and Cutting
[0038] The dried surfactant blend is then extruded. The extruder provides further opportunities
to blend in ingredients other than surfactants, or even to add further surfactants.
However, it is generally preferred that all of the anionic surfactant, or other surfactant
supplied in admixture with water; i.e. as paste or as solution, is added into the
drier to ensure that the water content can then be reduced and the material fed to
and through the extruder is sufficiently dry. Additional materials that can be blended
into the extruder are thus mainly those that are used at very low levels in a detergent
composition: such as fluorescer, shading dye, enzymes, perfume, silicone antifoams,
polymeric additives and preservatives. The limit on such additional materials blended
in the extruder has been found to be about 10 wt%, but it is preferred for product
quality to be ideal to keep it to a maximum of 5 wt%. Solid additives are generally
preferred. Liquids, such as perfume may be added at levels up to 2.5 wt%, preferably
up to 1.5 wt%. Solid particulate structuring (liquid absorbing) materials or builders,
such as zeolite, carbonate, silicate are preferably not added to the blend being extruded.
These materials are not needed due to the self structuring properties of the very
dry LAS-based feed material. If any is used the total amount should be less than 5
wt%, preferably less than 4 wt%, most preferably less than 3 wt%. At such levels no
significant structuring occurs and the inorganic particulate material is added for
a different purpose, for instance as a flow aid to improve the feed of particles to
the extruder.
[0039] The output from the extruder is shaped by the die plate used. The extruded material
has a tendency to swell up in the centre relative to the periphery. We have found
that if a cylindrical extrudate is regularly sliced as it exits the extruder the resulting
shapes are short cylinders with two convex ends. These particles are herein described
as oblate spheroids, or lentils. This shape is pleasing visually.
Coating
[0040] The sliced extruded particles are then coated. Coating allows the particles to be
coloured easily. Coating makes the particles more suitable for use in detergent compositions
that may be exposed to high humidity for long periods.
[0041] The extruded particles can be considered as oblate spheroids with a major radius
"a" and minor radius "b". Hence, the surface area(S) to volume (V) ratio can be calculated
as:

[0042] When ∈ is the eccentricity of the particle.
[0043] Although the skilled person might assume that any known coating may be used, for
instance organic, including polymer, it has been found to be particularly advantageous
to use an inorganic coating deposited by crystallisation from an aqueous solution
as this appears to give positive dissolution benefits and the coating gives a good
colour to the detergent particle, even at lower coating levels.
[0044] An aqueous spray-on of coating solution in a fluidised bed may also generate a further
slight rounding of the detergent particles during the fluidisation process.
[0045] Suitable inorganic coating solutions include sodium carbonate, possibly in admixture
with sodium sulphate, and sodium chloride. Food dyes, shading dyes, fluorescer and
other optical modifiers can be added to the coating by dissolving them in the spray-on
solution or dispersion. Use of a builder salt such as sodium carbonate is particularly
advantageous because it allows the detergent particle to have an even better performance
by buffering the system in use at an ideal pH for maximum detergency of the anionic
surfactant system. It also increases ionic strength, which is known to improve cleaning
in hard water, and it is compatible with other detergent ingredients that may be admixed
with the coated extruded detergent particles. If a fluid bed is used to apply the
coating solution, the skilled worker will know how to adjust the spray conditions
in terms of Stokes number and possibly Akkermans number (FNm) so that the particles
are coated and not significantly agglomerated. Suitable teaching to assist in this
may be found in
EP1187903,
EP993505 and
Powder technology 65 (1991) 257-272 (Ennis).
[0046] It will be appreciated by those skilled in the art that multiple layered coatings,
of the same or different coating materials, could be applied, but a single coating
layer is preferred, for simplicity of operation, and to maximise the thickness of
the coating. The amount of coating should lie in the range 3 to 50 wt% of the particle,
preferably 20 to 40 wt% for the best results in terms of anti-caking properties of
the detergent particles.
The Extruded Particulate Detergent Composition
[0047] The coated particles dissolve easily in water and leave very low or no residues on
dissolution, due to the absence of insoluble structurant materials such as zeolite.
The coated particles have an exceptional visual appearance, due to the smoothness
of the coating coupled with the smoothness of the underlying particles, which is also
believed to be a result of the lack of particulate structuring material in the extruded
particles.
[0048] Compositions with up to 100 wt% of the particles are possible when basic additives
are incorporated into the extruded particles, or into their coating. The composition
may also comprise, for example, an antifoam granule.
SHAPE AND SIZE
[0049] The coated detergent particle is preferably curved. The coated detergent particle
is most preferably lenticular (shaped like a whole dried lentil), an oblate ellipsoid,
where z and y are the equatorial diameters and x is the polar diameter; preferably
y = z. The size is such that y and z are at least 3 mm, preferably at least 4 mm,
most preferably at least 5 mm and x lies in the range 0.2 to 2 mm, preferably 1 to
2 mm.
[0050] The coated laundry detergent particle may be shaped as a disc.
CORE COMPOSITION
[0051] The core is primarily surfactant. It may also include detergency additives, such
as perfume, shading dye, enzymes, cleaning polymers and soil release polymers.
SURFACTANT
[0052] The coated laundry detergent particle comprises between 50 to 90 wt% of a surfactant,
most preferably 70 to 90 wt %. In general, the nonionic and anionic surfactants of
the surfactant system may be chosen from the surfactants described "
Surface Active Agents" Vol. 1, by Schwartz & Perry, Interscience 1949,
Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, in the
current edition of "McCutcheon's Emulsifiers and Detergents" published by Manufacturing
Confectioners Company or in "
Tenside Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981. Preferably the surfactants used are saturated.
1) Anionic Surfactants
[0053] Suitable anionic detergent compounds that may be used are usually water-soluble alkali
metal salts of organic sulphates and sulphonates having alkyl radicals containing
from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl
portion of higher acyl radicals. Examples of suitable synthetic anionic detergent
compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating
higher C8 to C18 alcohols, produced for example from tallow or coconut oil, sodium
and potassium alkyl C9 to C20 benzene sulphonates, particularly sodium linear secondary
alkyl C10 to C15 benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially
those ethers of the higher alcohols derived from tallow or coconut oil and synthetic
alcohols derived from petroleum. Most preferred anionic surfactants are sodium lauryl
ether sulphate (SLES), particularly preferred with 1 to 3 ethoxy groups, sodium C10
to C15 alkyl benzene sulphonates and sodium C12 to C18 alkyl sulphates. Also applicable
are surfactants such as those described in
EP-A-328 177 (Unilever), which show resistance to salting out, the alkyl polyglycoside surfactants described
in
EP-A-070 074, and alkyl monoglycosides. The chains of the surfactants may be branched or linear.
[0054] Soaps may also be present. The fatty acid soap used preferably contains from about
16 to about 22 carbon atoms, preferably in a straight chain configuration. The anionic
contribution from soap may be from 0 to 30 wt% of the total anionic. Use of more than
10 wt% soap is not preferred.
[0055] Preferably, at least 50 wt% of the anionic surfactant is selected from: sodium C11
to C15 alkyl benzene sulphonates; and, sodium C12 to C18 alkyl sulphates.
[0056] Preferably, the anionic surfactant is present in the coated laundry detergent particle
at levels between 15 to 85 wt%, more preferably 50 to 80wt%.
2) Non-Ionic Surfactants
[0057] Suitable non-ionic detergent compounds which may be used include, in particular,
the reaction products of compounds having a hydrophobic group and a reactive hydrogen
atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene
oxides, especially ethylene oxide either alone or with propylene oxide. Preferred
nonionic detergent compounds are C6 to C22 alkyl phenol-ethylene oxide condensates,
generally 5 to 25 EO, i.e. 5 to 25 units of ethylene oxide per molecule, and the condensation
products of aliphatic C8 to C18 primary or secondary linear or branched alcohols with
ethylene oxide, generally 5 to 50 EO. Preferably, the non-ionic is 10 to 50 EO, more
preferably 20 to 35 EO. Alkyl ethoxylates are particularly preferred.
[0058] Preferably the non-ionic surfactant is present in the coated laundry detergent particle
at levels between 5 to 75 wt%, more preferably 10 to 40 wt%.
[0059] Cationic surfactant may be present as minor ingredients at levels preferably between
0 to 5 wt%.
[0060] Preferably all the surfactants are mixed together before being dried. Conventional
mixing equipment may be used. The surfactant core of the laundry detergent particle
may be formed by roller compaction and subsequently coated with an inorganic salt.
Calcium Tolerant Surfactant System
[0061] In another aspect the core is calcium tolerant and this is a preferred aspect because
this reduces the need for a builder.
[0062] Surfactant blends that do not require builders to be present for effective detergency
in hard water are preferred. Such blends are called calcium tolerant surfactant blends
if they pass the test set out hereinafter. However, the invention may also be of use
for washing with soft water, either naturally occurring or made using a water softener.
In this case, calcium tolerance is no longer important and blends other than calcium
tolerant ones may be used.
[0063] Calcium-tolerance of the surfactant blend is tested as follows:
The surfactant blend in question is prepared at a concentration of 0.7 g surfactant
solids per litre of water containing sufficient calcium ions to give a French hardness
of 40 (4 x 10-3 Molar Ca2+). Other hardness ion free electrolytes such as sodium chloride,
sodium sulphate, and sodium hydroxide are added to the solution to adjust the ionic
strength to 0.05M and the pH to 10. The adsorption of light of wavelength 540 nm through
4 mm of sample is measured 15 minutes after sample preparation. Ten measurements are
made and an average value is calculated. Samples that give an absorption value of
less than 0.08 are deemed to be calcium tolerant.
[0064] Examples of surfactant blends that satisfy the above test for calcium tolerance include
those having a major part of LAS surfactant (which is not of itself calcium tolerant)
blended with one or more other surfactants (co-surfactants) that are calcium tolerant
to give a blend that is sufficiently calcium tolerant to be usable with little or
no builder and to pass the given test. Suitable calcium tolerant co-surfactants include
SLES 1-7EO, and alkyl ethoxylate non-ionic surfactants, particularly those with melting
points less than 40°C.
[0065] A LAS/SLES surfactant blend has a superior foam profile to a LAS Nonionic surfactant
blend and is therefore preferred for hand washing formulations requiring high levels
of foam. SLES may be used at levels of up to 30%. A preferred calcium tolerant coated
laundry detergent particle comprises 15 to 100 wt% anionic surfactant of which 20
to 30 wt % is sodium lauryl ether sulphate.
[0066] A LAS/NI surfactant blend provides a harder particle and its lower foam profile makes
it more suited for automatic washing machine use.
THE COATING
[0067] The coating may comprise a water soluble inorganic salt. Other water compatible ingredients
may be included in the coating. For example fluorescer, SCMC, shading dye, silicate,
pigments and dyes.
Water Soluble Inorganic Salts
[0068] The water soluble inorganic salts are preferably selected from sodium carbonate,
sodium chloride, sodium silicate and sodium sulphate, or mixtures thereof, most preferably
70 to 100 wt % sodium carbonate. The water soluble inorganic salt is present as a
coating on the particle. The water soluble inorganic salt is preferably present at
a level that reduces the stickiness of the laundry detergent particle to a point where
the particles are free flowing.
[0069] It will be appreciated by those skilled in the art that multiple layered coatings,
of the same or different coating materials, could be applied, but a single coating
layer is preferred, for simplicity of operation, and to maximise the thickness of
the coating. The amount of coating should lay in the range 15 to 45 wt % of the particle,
preferably 20 to 40 wt %, even more preferably 25 to 35 wt % for the best results
in terms of anti-caking properties of the detergent particles and control of the flow
from the package.
[0070] The coating is applied to the surface of the surfactant core, by crystallisation
from an aqueous solution of the water soluble inorganic salt. The aqueous solution
preferably contains greater than 50g/L, more preferably 200 g/L of the salt. An aqueous
spray-on of the coating solution in a fluidised bed has been found to give good results
and may also generate a slight rounding of the detergent particles during the fluidisation
process. Drying and/or cooling may be needed to finish the process.
[0071] By coating the large detergent particles of the current invention the thickness of
coating obtainable by use of a coating level of say 5 wt% is much greater than would
be achieved on typically sized detergent granules (0.5-2 mm diameter sphere).
[0072] For optimum dissolution properties, this surface area to volume ratio must be greater
than 3 mm
-1. However, the coating thickness is inversely proportional to this coefficient and
hence for the coating the ratio "Surface area of coated particle" divided by "Volume
of coated particle" should be less than 15 mm
-1.
The Coated Detergent Particle
[0073] Preferably, the coated detergent particle comprises from 70 to 100 wt %, more preferably
85 to 90 wt %, of a detergent composition in a package.
[0074] Preferably, the coated detergent particles are substantially the same shape and size
by this is meant that at least 90 to 100 % of the coated laundry detergent particles
in the in the x, y and z dimensions are within a 20%, preferably 10%, variable from
the largest to the smallest coated laundry detergent particle in the corresponding
dimension.
Water Content
[0075] The coated particles preferably comprise from 0 to 15 wt % water, more preferably
0 to 10 wt %, most preferably from 1 to 5 wt % water, at 293K and 50% relative humidity.
This facilitates the storage stability of the particle and its mechanical properties.
Other Ingredients
[0076] The ingredients described below may be present in the coating or the core.
Dye
[0077] Dye may advantageously be added to the coating; it may also or alternatively be added
to the core. In that case preferably the dye is dissolved in the surfactant before
the core is formed.
[0079] Dyes are selected from anionic and non-ionic dyes Anionic dyes are negatively charged
in an aqueous medium at pH 7. Examples of anionic dyes are found in the classes of
acid and direct dyes in the Color Index (Society of Dyers and Colourists and American
Association of Textile Chemists and Colorists). Anionic dyes preferably contain at
least one sulphonate or carboxylate groups. Non-ionic dyes are uncharged in an aqueous
medium at pH 7, examples are found in the class of disperse dyes in the Color Index.
[0080] The dyes may be alkoxylated. Alkoxylated dyes are preferably of the following generic
form: Dye-NR1 R2. The NR1 R2 group is attached to an aromatic ring of the dye. R1
and R2 are independently selected from polyoxyalkylene chains having 2 or more repeating
units and preferably having 2 to 20 repeating units. Examples of polyoxyalkylene chains
include ethylene oxide, propylene oxide, glycidol oxide, butylene oxide and mixtures
thereof.
[0081] A preferred polyoxyalkylene chain is [(CH2CR3HO)x(CH2CR4HO)yR5) in which x+y ≤ 5
wherein y ≥ 1 and z = 0 to 5, R3 is selected from: H; CH3; CH2O(CH2CH2O)zH and mixtures
thereof; R4 is selected from: H; CH2O(CH2CH2O)zH and mixtures thereof; and, R5 is
selected from: H; and, CH3
[0082] A preferred alkoxylated dye for use in the invention is:

[0083] Preferably the dye is selected from acid dyes; disperse dyes and alkoxylated dyes.
[0084] Most preferably the dye is a non-ionic dye.
[0085] Preferably the dye is selected from those having: anthraquinone; mono-azo; bis-azo;
xanthene; phthalocyanine; and, phenazine chromophores. More preferably the dye is
selected from those having: anthraquinone and, mono-azo chromophores.
[0086] In a preferred process, the dye is added to the coating slurry and agitated before
applying to the core of the particle. Application may be by any suitable method, preferably
spraying on to the core particle as detailed above.
[0087] The dye may be any colour, preferable the dye is blue, violet, green or red. Most
preferably the dye is blue or violet.
[0088] Preferably the dye is selected from: acid blue 80, acid blue 62, acid violet 43,
acid green 25, direct blue 86, acid blue 59, acid blue 98, direct violet 9, direct
violet 99, direct violet 35, direct violet 51, acid violet 50, acid yellow 3, acid
red 94, acid red 51, acid red 95, acid red 92, acid red 98, acid red 87, acid yellow
73, acid red 50, acid violet 9, acid red 52, food black 1, food black 2, acid red
163, acid black 1, acid orange 24, acid yellow 23, acid yellow 40, acid yellow 11,
acid red 180, acid red 155, acid red 1, acid red 33, acid red 41, acid red 19, acid
orange 10, acid red 27, acid red 26, acid orange 20, acid orange 6, sulphonated Al
and Zn phthalocyanines, solvent violet 13, disperse violet 26, disperse violet 28,
solvent green 3, solvent blue 63, disperse blue 56, disperse violet 27, solvent yellow
33, disperse blue 79:1.
[0089] The dye is preferably a shading dye for imparting a perception of whiteness to a
laundry textile.
[0090] The dye may be covalently bound to polymeric species.
[0091] A combination of dyes may be used.
Fluorescent Agent
[0092] The coated laundry detergent particle preferably comprises a fluorescent agent (optical
brightener). Fluorescent agents are well known and many such fluorescent agents are
available commercially. Usually, these fluorescent agents are supplied and used in
the form of their alkali metal salts, for example, the sodium salts. The total amount
of the fluorescent agent or agents used in the composition is generally from 0.005
to 2 wt %, more preferably 0.01 to 0.1 wt %. Suitable Fluorescers for use in the invention
are described in
chapter 7 of Industrial Dyes edited by K. Hunger 2003 Wiley-VCH ISBN 3-527-30426-6.
[0093] Preferred fluorescers are selected from the classes distyrylbiphenyls, triazinylaminostilbenes,
bis(1,2,3-triazol-2-yl)stilbenes, bis(benzo[b]furan-2-yl)biphenyls, 1,3-diphenyl-2-pyrazolines
and courmarins. The fluorescer is preferably sulphonated.
[0094] Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade
Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure
Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN.
Preferred fluorescers are: sodium 2 (4-styryl-3-sulfophenyl)-2H-napthol[1,2-d]triazole,
disodium 4,4'-bis{[(4-anilino-6-(N methyl-N-2 hydroxyethyl) amino 1,3,5-triazin-2-yl)]amino}stilbene-2-2'
disulfonate, disodium 4,4'-bis{[(4-anilino-6-morpholino-1,3,5-triazin-2-yl)]amino}
stilbene-2-2' disulfonate, and disodium 4,4'-bis(2-sulfostyryl)biphenyl.
[0095] Tinopal® DMS is the disodium salt of disodium 4,4'-bis{[(4-anilino-6-morpholino-1,3,5-triazin-2-yl)]amino}
stilbene-2-2' disulfonate. Tinopal® CBS is the disodium salt of disodium 4,4'-bis(2-sulfostyryl)biphenyl.
Perfume
[0097] It is commonplace for a plurality of perfume components to be present in a formulation.
In the compositions of the present invention it is envisaged that there will be four
or more, preferably five or more, more preferably six or more or even seven or more
different perfume components.
[0099] The perfume may be added into the core either as a liquid or as encapsulated perfume
particles. The perfume may be mixed with a nonionic material and applied as a coating
the extruded particles, for example by spraying it mixed with molten nonionic surfactant.
Perfume may also be introduced into the composition by means of a separate perfume
granule and then the detergent particle does not need to comprise any perfume.
[0100] It is preferred that the coated detergent particles do not contain a peroxygen bleach,
e.g., sodium percarbonate, sodium perborate, peracid.
Polymers
[0101] The composition may comprise one or more further polymers. Examples are carboxymethylcellulose,
poly (ethylene glycol), poly(vinyl alcohol), polyethylene imines, ethoxylated polyethylene
imines, water soluble polyester polymers polycarboxylates such as polyacrylates, maleic/acrylic
acid copolymers and lauryl methacrylate/acrylic acid copolymers.
Enzymes
[0102] One or more enzymes are preferably present in the composition.
[0103] Preferably the level of each enzyme is from 0.0001 wt% to 0.5 wt% protein.
[0104] Especially contemplated enzymes include proteases, alpha-amylases, cellulases, lipases,
peroxidases/oxidases, pectate lyases, and mannanases, or mixtures thereof.
[0105] Suitable lipases include those of bacterial or fungal origin. Chemically modified
or protein engineered mutants are included. Examples of useful lipases include lipases
from Humicola (synonym Thermomyces), e.g. from H. lanuginosa (T. lanuginosus) as described
in
EP 258 068 and
EP 305 216 or from H. insolens as described in
WO 96/13580, a Pseudomonas lipase, e.g. from P. alcaligenes or P. pseudoalcaligenes (
EP 218 272), P. cepacia (
EP 331 376), P. stutzeri (
GB 1,372,034), P. fluorescens, Pseudomonas sp. strain SD 705 (
WO 95/06720 and
WO 96/27002), P. wisconsinensis (
WO 96/12012), a Bacillus lipase, e.g. from B. subtilis (
Dartois et al. (1993), Biochemica et Biophysica Acta, 1131, 253-360), B. stearothermophilus (
JP 64/744992) or B. pumilus (
WO 91/16422).
[0106] Other examples are lipase variants such as those described in
WO 92/05249,
WO 94/01541,
EP 407 225,
EP 260 105,
WO 95/35381,
WO 96/00292,
WO 95/30744,
WO 94/25578,
WO 95/14783,
WO 95/22615,
WO 97/04079 and
WO 97/07202,
WO 00/60063,
WO 09/107091 and
WO09/111258.
[0107] Preferred lipase enzymes include Lipolase™ and Lipolase Ultra™, Lipex™ (Novozymes
A/S) and Lipoclean™.
[0108] The method of the invention may be carried out in the presence of phospholipase classified
as EC 3.1.1.4 and/or EC 3.1.1.32. As used herein, the term phospholipase is an enzyme
that has activity towards phospholipids.
[0109] Phospholipids, such as lecithin or phosphatidylcholine, consist of glycerol esterified
with two fatty acids in an outer (sn-1) and the middle (sn-2) positions and esterified
with phosphoric acid in the third position; the phosphoric acid, in turn, may be esterified
to an amino-alcohol. Phospholipases are enzymes that participate in the hydrolysis
of phospholipids. Several types of phospholipase activity can be distinguished, including
phospholipases A1 and A2 which hydrolyze one fatty acyl group (in the sn-1 and sn-2
position, respectively) to form lysophospholipid; and lysophospholipase (or phospholipase
B) which can hydrolyze the remaining fatty acyl group in lysophospholipid. Phospholipase
C and phospholipase D (phosphodiesterases) release diacyl glycerol or phosphatidic
acid respectively.
[0110] Suitable proteases include those of animal, vegetable or microbial origin. Microbial
origin is preferred. Chemically modified or protein engineered mutants are included.
The protease may be a serine protease or a metallo protease, preferably an alkaline
microbial protease or a trypsin-like protease. Suitable protease enzymes include Alcalase™,
Savinase™, Primase™, Duralase™, Dyrazym™, Esperase™, Everlase™, Polarzyme™, and Kannase™,
(Novozymes A/S), Maxatase™, Maxacal™, Maxapem™, Properase™, Purafect™, Purafect OxP™,
FN2™, and FN3™ (Genencor International Inc.).
[0111] The method of the invention may be carried out in the presence of cutinase. classified
in EC 3.1.1.74. The cutinase used according to the invention may be of any origin.
Preferably, cutinases are of microbial origin, in particular of bacterial, of fungal
or of yeast origin.
[0112] Suitable amylases (alpha and/or beta) include those of bacterial or fungal origin.
Chemically modified or protein engineered mutants are included. Amylases include,
for example, alpha-amylases obtained from Bacillus, e.g. a special strain of B. licheniformis,
described in more detail in
GB 1,296,839, or the Bacillus sp. strains disclosed in
WO 95/026397 or
WO 00/060060. Suitable amylases are Duramyl™, Termamyl™, Termamyl Ultra™, Natalase™, Stainzyme™,
Fungamyl™ and BAN™ (Novozymes A/S), Rapidase™ and Purastar™ (from Genencor International
Inc.).
[0113] Suitable cellulases include those of bacterial or fungal origin. Chemically modified
or protein engineered mutants are included. Suitable cellulases include cellulases
from the genera Bacillus, Pseudomonas, Humicola, Fusarium, Thielavia, Acremonium,
e.g. the fungal cellulases produced from Humicola insolens, Thielavia terrestris,
Myceliophthora thermophila, and Fusarium oxysporum disclosed in
US 4,435,307,
US 5,648,263,
US 5,691,178,
US 5,776,757,
WO 89/09259,
WO 96/029397, and
WO 98/012307. Cellulases include Celluzyme™, Carezyme™, Endolase™, Renozyme™ (Novozymes A/S),
Clazinase™ and Puradax HA™ (Genencor International Inc.), and KAC-500(B)™ (Kao Corporation).
[0114] Suitable peroxidases/oxidases include those of plant, bacterial or fungal origin.
Chemically modified or protein engineered mutants are included. Examples of useful
peroxidases include peroxidases from Coprinus, e.g. from C. cinereus, and variants
thereof as those described in
WO 93/24618,
WO 95/10602, and
WO 98/15257. Peroxidases include Guardzyme™ and Novozym™ 51004 (Novozymes A/S).
Enzyme Stabilizers
[0116] Any enzyme present in the composition may be stabilized using conventional stabilizing
agents, e.g., a polyol such as propylene glycol or glycerol, a sugar or sugar alcohol,
lactic acid, boric acid, or a boric acid derivative, e.g., an aromatic borate ester,
or a phenyl boronic acid derivative such as 4-formylphenyl boronic acid, and the composition
may be formulated as described in e.g.
WO 92/19709 and
WO 92/19708.
[0117] Sequestrants may be present in the detergent particles.
[0118] The invention will be further described with reference to the following non-limiting
examples.
EXAMPLES
[0119] In example 1 coated large detergent particles are manufactured, following the process
in
PCT/EP2010/055256.
EXAMPLE 1 - Preparation of the coated particles
[0120] Surfactant raw materials were mixed together to give a 67 wt% active paste comprising
85 parts LAS (linear alkyl benzene sulphonate), 15 parts Nonionic Surfactant. The
raw materials used were:
LAS: Unger Ufasan 65
Nonionic: BASF Lutensol AO30
[0121] The paste was pre-heated to the feed temperature and fed to the top of a wiped film
evaporator to reduce the moisture content and produce a solid intimate surfactant
blend, which passed the calcium tolerance test. The conditions used to produce this
LAS/NI blend are given in Table 1.
Table 1
| |
Jacket Vessel Temp. |
81 °C |
| Feed |
Nominal Throughput |
55 kg/hr |
| Temperature |
59 °C |
| Density |
1.08 kg/l |
| Product |
Moisture(KF*) |
0.85% |
| Free NaOH |
0.06 % |
| *analysed by Karl Fischer method |
[0122] On exit from the base of the wiped film evaporator, the dried surfactant blend dropped
onto a chill roll, where it was cooled to less than 30°C.
[0123] After leaving the chill roll, the cooled dried surfactant blend particles were milled
using a hammer mill, 2% Alusil® was also added to the hammer mill as a mill aid.
[0124] The resulting milled material is hygroscopic and so it was stored in sealed containers.
[0125] The cooled dried milled composition was fed to a twin-screw co-rotating extruder
fitted with a shaped orifice plate and cutter blade. A number of other components
were also dosed into the extruder as shown in Table 2.
Table 2
| |
Example 1 |
| Extruder |
Parts (final particle = 100) |
| LAS/NI mixture |
64.3 |
| SCMC |
1.0 |
| Perfume |
0.75 |
[0126] The average particle diameter and thickness of samples of the extruded particles
were found to be 4.46 mm and 1.13 mm respectively. The standard deviation was acceptably
low.
[0127] The particles were then coated using a Strea 1 fluid bed. The coating was added as
an aqueous solution and coating completed under conditions given in Table 3. Coating
wt% is based on weight of the coated particle.
Table 3
| Example |
1 |
| Mass Solid [kg] |
1.25 |
| Coating Solution |
Sodium Carbonate (30%) |
| Mass Coating Solution [kg] |
1.8 |
| Air Inlet Temperature [°C] |
80 |
| Air Outlet Temperature [°C] |
38 |
| Coating Feed Rate [g/min] |
16 |
| Coating Feed temperature [°C] |
55 |
[0128] Coated particles composition is given in Table 4.
Table 4
| |
Example 1 |
| Extruder |
Parts (final particle = 100) |
| LAS/NI mixture |
64.30 |
| SCMC |
1.00 |
| Perfume |
0.75 |
| Fluid bed |
|
| Carbonate |
28.25 |
| Minors/Moisture |
5.70 |
[0129] The coated extruded particles have an excellent appearance due to their high surface
smoothness. Without wishing to be bound by theory it is thought that this is because
the uncoated particles are larger and more flattened than usual detergent particles
and that their core has a much lower solids content than usual (indeed it is free
of solid structuring materials, unlike prior art coated extruded particles).
Example 2
[0130] We measured the ratio of Tapped BD to Poured BD for the coated particles from example
1 (oblate spheroids) and two conventional laundry detergent powders. The results are
given in table 5.
[0131] Poured BD - The bulk density of the whole detergent composition in the uncompacted
(untapped) aerated form, determined by measuring the increase in weight due to pouring
the composition to fill a 1 litre container. In fact the container is overfilled and
then excess powder removed by moving a straight edge over the brim to leave the contents
level to the maximum height of the container.
[0132] Tapped BD - The BD container was fitted with a removable collar to extend the height
of the container. This extended container was then filled via the poured BD technique.
The extended container was then placed on a Retsch Sieve Shaker and allowed to vibrate/tap
for 5 min using the 0.2mm/"g" setting on the instrument. The collar was then removed
and the excess powder levelled as per the standard BD measurement, the mass of the
container measured and the Tapped BD calculated in the usual way.
Table 5
| Particle |
Poured BD:tapped BD |
| Coated large size Oblate spheroids * |
1.10 |
| Prior art powder composition 1 "OMO" brand |
1.10 |
| Prior art powder composition 2: "Ariel" brand |
1.15 |
| *extruded 5mm diameter and cut to 1 mm thick before spray coating with sodium carbonate
solution to give a particle having a 30 wt% sodium carbonate coating which is an oblate
spheroid with slightly flattened sides resulting from the extrusion. |
[0133] As can be seen from table 1 the larger coated particles of the invention settle down
in much the same way as the prior art powders. The small difference in the ratios
of Poured BD to tapped BD is not significant.
Example 3
[0134] We measured settling volume after tapping for 1 min using the Retsch sieve shaker
at a setting of 0.2 mm/"g". The results are given in table 6.
Table 6
| Sample |
Initial volume |
Final volume |
| Coated large size Oblate spheroids * |
500ml |
480ml |
| Prior art powder composition 1 "OMO" brand |
500ml |
470ml |
| Prior art powder composition 2: "Ariel" brand |
500ml |
445ml |
[0135] Only the crystals flowed freely out of the measuring cylinder after this experiment.
In contrast, both of the prior art powders were compacted and the cylinder needed
tapping to get them to flow.
Example 4
[0136] Standard DFR (Dynamic Flow Rate) is measured in ml/sec using a cylindrical glass
tube having an internal diameter of 35 mm and a length of 600 mm. The tube is securely
clamped with its longitudinal axis vertical. Its lower end is terminated by means
of a smooth cone of polyvinyl chloride having an internal angle of 15 DEG and a lower
outlet orifice of diameter 22.5 mm. A beam sensor is positioned 150 mm above the outlet,
and a second beam sensor is positioned 250 mm above the first sensor.
[0137] To determine the dynamic flow rate of a detergent composition sample, the outlet
orifice is temporarily closed, for example, by covering with a piece of card, and
detergent composition is poured into the top of the cylinder until the detergent composition
level is about 100 mm above the upper sensor. The outlet is then opened and the time
t (seconds) taken for the detergent composition level to fall from the upper sensor
to the lower sensor is measured electronically. The DFR is the tube volume between
the sensors, divided by the time measured. We mounted this equipment onto the sieve
shaker set at 0.2mm/"g" for 1 min. The shaking or vibration being done after filling
the cylinder and before the outlet is opened. Each sample was given one "prod" after
vibration to initiate flow as the outlet was narrow and tended to block with all powders.
If one prod was insufficient to start flow then zero flow rate was recorded. Results
are given in table 7.
Table 7
| Sample |
Poured DFR ml/s |
Tapped DFR ml/s |
| Coated large size Oblate spheroids * |
98 |
99 |
| Prior art powder composition 1 "OMO" brand |
114 |
0 |
| Prior art powder composition 2: "Ariel" brand |
51 |
0 |
[0138] It can be seen from table 7 that the crystals have much improved retention of their
flow properties under these conditions - it remained to be determined whether this
better retention of flow for the crystals was due to their greater size, their non-spherical
shape, or their coating (it being assumed that the spherical powders were not coated).
Example 5
[0139]
Table 8
| |
Poured DFR ml/s |
Tapped DFR ml/s |
| Prior art coated granule (small ∼500µm sphere and coated) |
160 |
152 |
| Uncoated large size oblate spheroids |
134 |
124 |
[0140] The DFR of the uncoated crystals was worse than the smaller spherical coated particles
under both tests (tapped and untapped). Uncoated crystals do however, flow much better
than the uncoated prior art powders. It is thus feasible to use a small proportion
of uncoated crystals in the composition, say up to 30% of the total particles, preferably
up to 15% by number.
[0141] Surprisingly, from table 8, the coated crystals, despite their superior appearance
to the uncoated crystals have a lower DFR then the uncoated ones, hence the coating
is improving appearance but not the flow. However, the coated crystals do have a very
consistent DFR. They seem to flow the same way reliably no matter what their history.
[0142] Various non-limiting embodiments of the invention will now be more particularly described
with reference to the following figures in which:
Figure 1 shows a blister pack according to the invention, with a rigid support rack
(shown separated);
Figure 2 shows the dispenser of figure 1 in use with manual force being applied to
eject a dose from the blister pack; and
Figure 3 shows an exploded view of the dispenser of figure 1 being installed in a
washing machine drawer.
[0143] Referring to figures 1 and 2, a dispenser 1 is shown, the dispenser 1 for dispensing
a blister pack 3 of predetermined doses 5 of concentrated laundry composition according
to any of the examples above, into a washing machine (not shown). The dispenser 1
comprises a rigid support frame 7 on which is mounted the blister pack 3 whereby manual
force on a selected dose ejects that dose 5 from the blister pack 3. The blister pack
comprises a planar sheet of plastic provided with individual reservoirs comprising
"blisters" 5 which are concave protrusions configured in rows and columns. The blister
pack 3 further comprises at least one backing layer (not shown) which is fastened
to the solid receiving side of the blister pack. This layer is a low strength retaining
layer. This low strength retaining layer stretches across the backs of the blisters
5 and retains the individually sealed within each of the blisters 5. Preferably the
blister pack 3 is mounted with the low strength retaining layer facing down. The package
is sufficiently rigid in material and/or construction such that a portion e.g. the
base or a side wall, can be tapped to move the particles from the reservoir/s and
preferably such tapping creates audible feedback to the user to guide them as to the
movement of the particles. Suitable materials for the package include, but are not
limited to: polypropylene (PP), polyethylene (PE), polycarbonate (PC), polyamides
(PA) and/or polyethylene terephthalate (PETE), polyvinylchloride (PVC); and polystyrene
(PS). The reservoirs may formed by moulding e.g. blow moulding from a preform or by
thermoforming or by injection moulding.
[0144] Figure 3 shows an exploded view of the dispenser being installed into the drawer
11 of an automatic washing machine (machine not shown). The drawer 11 is provided
with a plurality of separate compartments and the dispenser is being installed into
the middle compartment 11, for containing main wash products to be flushed by an incoming
water flow (not shown) into the machine drum. The dispenser 1 is installed in a machine
drawer so manual force on a selected dose ejects this dose from the blister pack directly
into the drawer compartment 13. The rigid support frame 7 comprises apertures 15 in
each wall. The frame 7 also has smooth contours 17 and generally convex rather than
concave surfaces configuration/patterning such that water and/or laundry composition
cannot become trapped. The dispensing device is an injection moulded plastic, water
insoluble and of robust construction so that removal during the washing process is
not required. The dispenser may be constructed of any suitable material such as a
water insoluble material such as a polyolefin e.g. polypropylene (PP), polyethylene
(PE), polyethylene terephthalate (PET). The frame has sufficient rigidity to withstand
the manual force required to break the blister pack but has elasticity at higher manual
forces in that the walls 7
a can be flexed against the sides 13
a of the drawer compartment during fitting. Once in place, manual pressure is released
so as to urge the walls 7
a against the sides 13
a of the drawer compartment 13, thereby preventing movement of the dispensing device
1 whilst in place in the drawer 11. The frame 7 comprises a wall or walls having supporting
upper edges 17 which correspond to an outer perimeter of the blisters 5 so that the
pack is supported further. The support frame has an upper supporting edge 19 which
is inclined with respect to the base 21, whereby the mounted blister pack 3 is also
inclined. With this arrangement, the blister pack 3 may be better viewed by the user.
The device is removable, however, it may contain temporary means of retaining the
device in place for a single or multiple washes such as flexible walls as referred
to above but also adhesive .
[0145] It is of course to be understood that the invention is not intended to be restricted
to the details of the above embodiment which are described by way of example only.