Note: Descriptions are shown in the official language in which they were submitted.
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WATER UNSTABLE FOAM
Technical field of the invention
The present invention relates to foam components, typically particles,
comprising a
matrix formed from a polymeric material and a plasticiser, a dissolution agent
and an
active ingredient, such as a detergent active ingredient, typically to be
delivered to an
aqueous environment.
Background to the invention
Compositions such as cleaning products and personal care products, cosmetic
products
and pharmaceutical products, often comprise active ingredients which are to be
delivered
to water or which are required to be active in an aqueous environment. Many of
these
active ingredients are sensitive to moisture, temperature changes, light
and/or air during
storage.
Another problem with many of these active ingredients, in particular enzymes,
is that they
tend to form dust due to physical forces directed upon them during handling.
This not
only creates waste product, but the dust can also cause hygiene and health
problems.
Attempts to overcome these problems have led to the development of protecting
these
active ingredients by coating agents or encapsulating agents. The problem with
many of
these coated particles is that they do not always exhibit sufficient impact
resistance
during handling, and when acted upon by physical forces typically encountered
during
handling, dust is formed which can cause hygiene and health problems. Also,
these
coated particles are not always readily soluble in aqueous environments and
exhibit poor
dissolution properties upon contact with water.
The Inventors have found an improved method of protecting active ingredients
and
delivering these active ingredients to aqueous environments. They have found
that
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specific foam components comprising a matrix formed from a polymeric material
and a
plasticiser, are very impact robust and the active ingredient which is
incorporated therein
is protected against physical forces acting upon said foam component.
Furthermore, the
Inventors have found that when a dissolution aid is also incorporated in the
foam
component, the foam component dissolves or disintegrates readily upon contact
with
water releasing the active ingredient to the aqueous environment.
Thus, the foam component of the present invention is very impact resistant,
thus resulting
in reduced breaking-up or abrasion during handling and reduced dust formation,
and
readily soluble upon contact with water. For example, foam components, such as
particles
or beads, comprising enzymes can be obtained which are safer and more
efficient to
handle and use. Moreover, these component can be made such that they deliver
the active
ingredients incorporated therein, such as enzymes, very efficiently to an
aqueous
environment. The component of the present invention is air-stable under normal
humidity
storage conditions, but unstable upon contact with water, to thus deliver the
active
ingredient. The foam component is useful in any product, especially useful in
cleaning
products, pharmaceutical products, personal care products, cosmetic products
and fabric
care products.
Summary of the invention
The present invention provides a foam component comprising a mixture of a
polymeric
material, a dissolution aid, and an active ingredient, preferably being active
in an aqueous
environment, the foam component being stable upon contact with air and
unstable upon
contact with water.
The dissolution aid improves the water-solubility or water-disintegration of
the foam
component.
It may be preferred that the dissolution aid of said foam component comprises
an
effervescence system, a hydrotrope, or a combination thereof.
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The present invention also relates to processes for making the foam component.
Preferably the foam component is obtainable by a process comprising the steps
of;
a) obtaining a polymeric material; and
b) chemically or physically introducing a gas in said polymeric material; and
c) prior to step b) and/or simultaneous with step b) and /or subsequent to
step b),
contacting an active ingredient to said polymeric material; and
d) prior to step b) and/or simultaneous with step b) and /or subsequent to
step b),
contacting a dissolution aid to said polymeric material; and
e) shaping the components of the resulting polymeric material;
whereby preferably one or more steps a) to e) are followed or accompanied by
the
removal of part of the water, if present.
In another embodiment of the present invention, the use of a foam component is
provided,
to deliver active ingredients to an aqueous environment, preferably the active
ingredients
being detergent active ingredients, preferably enzymes, and the aqueous
environment
being the wash water.
Detailed description of the invention
Foam component
The foam component of the present invention, herein referred to as
"component",
comprises an active ingredient, a matrix and a dissolution aid. Said active
ingredient,
matrix and dissolution aid are described in more detail hereinafter.
Said component herein is preferably water-dispersible, water-disintegrating or
water-
soluble. Preferred water-dispersible components herein have a dispersibility
of at least
50%, preferably at least 75% or even at least 95%, as measured by the method
set out
hereinafter using a glass-filter with a maximum pore size of 50 microns; more
preferably
the component herein is water-soluble or water-disintegrating and has a
solubility or
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disintegration of at least 50%, preferably at least 75% or even at least 95%,
as measured
by the method set out hereinafter using a glass-filter with a maximum pore
size of 20
microns, namely:
Gravimetric method for determining water-solubility, water-disintegration or
water-
dispersibility of the component herein:
50 grams ~ 0.1 gram of the component herein is added in a 400 ml beaker,
whereof the
weight has been determined, and 245m1 ~ lml of distilled water is added. This
is stirred
vigorously on magnetic stirrer set at 600 rpm, for 30 minutes. Then, the
component -
mixture is filtered through a folded qualitative sintered-glass filter with
the pore sizes as
defined above (max. 20 or 50 microns). The water is dried off from the
collected filtrate
by any conventional method, and the weight of the remaining component fraction
is
determined (which is the dissolved, disintegrated or dispersed fraction).
Then, the
solubility, disintegration or dispersibility can be calculated.
The component herein is typically used to deliver actives to aqueous
environment. Then,
the component herein, and preferably the matrix thereof, is unstable when
brought into
contact with water. This occurs such that the active ingredients) or part
thereof, present
in the component is delivered to a liquid, preferably an aqueous environment
such as
water. Preferably the component or part thereof denatures, disintegrates,
preferably
disperses or dissolves in liquid, preferably in an aqueous environment, more
preferably in
water. It may be preferred that the active ingredient is delivered rapidly to
water and that
the component is such that it disperses or dissolves rapidly; preferably at
least 10% of the
component, by weight, is dissolved or dispersed in 30 minutes after contacting
said
component with water, or more preferably at least 30% or even at least 50% or
even at
least 70% or even at least 90% (introduced in the water at a 1 % by weight
concentration).
It may even be preferred that this happens within 20 minutes or even 10
minutes or even
5 minutes after contacting the component with the water. The dissolution or
dispersion
can be measured by the method described hereinbefore for measuring the
dissolution,
disintegration and dispersion of the component herein.
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Preferably the component is such that the total volume of the component is
changed,
preferably reduced, with at least 10%, compared to the initial total volume,
as for
example can be determined when 1 cm3 of the component is added to 100 ml of
demineralised water upon and stirred for 5 minutes at a speed of 200rpm, at a
temperature
of 25°C. Preferably the change, or preferably reduction, in total
volume is at least 20% or
even at least 40% or even at least 60% or even at least 90% or even about
100%, e.g.
because it may be preferred that substantially the whole component is
disintegrated,
dispersed or preferably dissolved into the water quickly.
This can be measured by use of any method known in the art, in particular
herein with a
method as follows (double immersion technique):
1 cm3 of a component is obtained and introduced in a 100 ml micro volumetric
measuring
cylinder which is filled with 50 ml ~ O.lml of an organic inert solvent.
Acetone is for
example used when found to be neither denaturing and/or not interacting with
the
polymeric material in the matrix of the component herein, for example when
this is PVA.
Other neutral organic medium can be used according to the nature of the
article under
investigation; the inert solvent is such that the component is substantially
not dissolved,
dispersed, disintegrated or denatured by the solvent.
The cylinder is air sealed and left to rest for 1 minute so that the solvent
penetrates the
whole component. The change in volume is measured and taken as the original
volume V;
of the foam specimen. The component is then removed from the solvent and left
to dry in
air so that the solvent evaporates.
The component is then placed in a 250 ml beaker containing 100 ml of
demineralised
water, maintained at 25°C, under stirring at 200 rpm with the help of a
magnetic stirrer,
for 5 minutes. The remaining of the component specimen, if any, is filtered
off with a
60mm mesh copper filter and placed in an oven at a temperature and for a
period such
that residual water is removed. The dried remaining component is re-introduced
in the
measuring cylinder which volume of acetone had been re-adjusted to 50 ml.
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The increase in total volume is monitored and taken as the final volume of the
component
Vf.. The decrease in total volume 0V of the component specimen is then:
%0V = ~f * 100
VI
The component preferably has a relative density p* of from 0.01 to 0.95, more
preferably
from 0.05 to 0.9 or even from 0.1 to 0.8 or even form 0.3 to 0.7. The relative
density is
the ratio of the density of the component (p*), to the sum of the partial
densities of all the
bulk materials used to form component(ps).
The preferred foamed component as used herein is air-stable or stable upon
contact with
air, which means herein that the bulk volume of the component or matrix
thereof
substantially remains the same when exposed to air. This means in particular
that the
component retains preferably from 75% to 125% or even from 90% to 110% or even
from 95% to 100% of its bulk volume when stored in an open beaker (9 cm
diameter;
without any protective barner) in a incubator under controlled ambient
conditions
(humidity = RH 60%, temperature = 25°C ) for 24 hours. Preferably the
component
retains from 75% to 125% or even from 90% to 110% or even from 95% to 100% of
its
bulk volume under the above storage conditions whereby the humidity is 80%.
The bulk volume change can be measured by any conventional method. In
particular
useful is a digital image recorder system containing a digital camera coupled
to a personal
computer itself equipped with calibrated image analyser software. A 1 cm3
specimen of
the component is obtained and introduced in an open beaker having a diameter
of 9 cm
and stored for 24 hours at the above conditions. After 24 hours, the size in
all three
dimensions is measured with the image analysis recorder system. Each specimen
measurement is repeated three times, and the average bulk volume change is
calculated in
%.
Preferably, the component is such that, when in the form of particles of a
mean particle
size of 2000 microns or less, these particles also retain from 75% to 125% or
even from
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90% to 110% or even from 95% to 100% of their bulk volume. This can for
example be
measured by placing 20 grams of such particles, or a weight comprising more
than 500
particles, in a volumetric beaker having a diameter of 9 cm. The beaker is
taped lightly on
its base until the particles re-arrange themselves in a stable position with a
horizontal top
surface. The volume is measured. The open beaker with the particles is then
carefully
placed in the incubator for 24 hours, set to the desired %RH and temperature.
The bulk
volume after the 24 hours is measured and the change of bulk volume is
calculated in %.
The component comprises (by weight) preferably at least 1 % active
ingredient(s), more
preferably from 5% to 70%, more preferably at least 10% by weight of the
component,
more preferably from 15% or even 20% or even 25% to 50%.
The component comprises (by weight) preferably from 10% to 99% matrix, more
preferably at least 20% or even 30% to 99%, more preferably from 20% or 30% to
90%
to 80%.
The component comprises ( by weight) at least 1% dissolution aid, more
preferably from
5%, or from 10%, or from 15%, or from 20%, and to 50%, or to 40%, or to 30%,
or to
25%.
Matrix
The matrix of the component of the present invention, herein referred to as
"matrix", is
formed form a polymeric material and a plasticiser. Said polymeric material
and said
plasticiser are described in more detail hereinafter.
The ratio of plasticiser to polymeric material in the matrix is preferably 1
to 100, more
preferably 1 to 70 or 1 to 50, more preferably 1 to 30 or even 1 to 20,
depending on the
type of plasticiser and polymeric material used. For example, when the
polymeric
material comprises PVA and the plasticiser comprises glycerine or glycerol
derivatives
and optionally water, the ratio is preferably around 1:15 to 1:8, a preferred
ratio being
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around 10:1.
The matrix herein may further comprise the active ingredient of the component
herein
and/or the dissolution aid of the component herein. Said active ingredient and
said
dissolution aid are described in more detail hereinafter. Cross-linking agents
may also be
added to modify the properties of the matrix or the resulting component as
appropriate.
Borate may be useful in the matrix herein.
The matrix herein preferably has a glass transition temperature (Tg) of below
SO°C,
preferably below 40°C, preferably less than 20°C or even less
than 10°C or even less than
0°C. Preferably the matrix herein has a Tg of above -20°C or
even above -10°C.
The Tg of the matrix when used herein, is the Tg of the matrix as present in
the
component, which thus may be a mixture of polymeric material and plasticiser
alone, or a
1 S mixture of polymeric material, plasticiser, active ingredient and/or
dissolution aid, and in
any case, optional additional ingredients may be present (such as, stability
agents,
densification aids, fillers, lubricants etc., as described hereinafter).
The Tg as used herein is as defined in the text book 'Dynamic Mechanical
Analysis'
(page 53, figure 3.1 lc on page 57), as being the temperature of a material
(matrix) where
the material (matrix) changes from glassy to rubbery, namely where chains gain
enough
mobility to slide by each other.
The Tg of the matrix of the component of the invention can be measured in the
Perkin-
Elmer DMA 7e equipment, following the directions in operations manual for this
equipment, generating a curve as illustrated in the book Dynamic Mechanical
Analysis -
page 57, figure 3-l lc. The Tg is the temperature or log Frequency as measured
with this
equipment, between the glass and 'leathery region', as defined in that text.
The matrix, and preferably the component as a whole, has a specific elasticity
and
flexibility, because of its specific glass transition temperature. In
particular, this means
that the matrix and the component reversibly deform, absorbing the energy of
impacts or
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of forces so that the component or matrix remains substantially its original
bulk volume
after the physical force seizes to be applied on the component.
The elasticity can be defined by the elastic modulus of the matrix, or even
the component,
which again can be defined by the Young's modulus. This can be calculated from
strain
or stress mechanical tests as known in the art, for example by using Perkin-
Elmer DMA
7e equipment following the manufacturer's experimental procedure over a
specific
static strain range, namely in the range of 10-40% static strain. This
represents a
maximum strain as could be applicable during normal manufacturing or handling.
Thus,
the elastic modulus as defined herein is the maximum modulus as measured with
this
equipment in the range of 10% to 40% static strain. For example a piece of
matrix (or
component) of 1 cm3 can be used in the testing with this equipment.
The matrix herein typically has an elastic modulus or Young's modulus of less
than 4
GN.rri z, or typically less than 2 GN.rri Z, even more preferentially less
than 1 GN.rri Z, but
typically even less than 0.5 GN.rri 2, or even less than 0.1 GN.rri 2, or even
less than 0.01
GN.rri Z, as measured with the Perkin-Elmer DMA 7e equipment. In particular a
matrix
herein which contains gas bubbles, e.g. formed by processes involving the
introduction of
air in the matrix, has an elastic modulus below 0.1 GN.rri 2 or even 0.01
GN.rri z or even
below 0.005 GN.rri 2 or even below 0.0001 GN.rri z.
Preferably the matrix is flexible, such that it has a relative yield strain
greater than 2%,
and preferably greater than 15% or even greater than 50%, as measured with the
Perkin-
Elmer DMA 7e equipment. (The yield strain is in this measurement the limit
deformation
of a piece of matrix at which the it deforms irreversible).
In particular this means that when a matrix sample having a cross section of a
specific
length, for example 1 cm, is compressed with a static force applied along the
axis of that
cross section, the static force being variable but at least equivalent to
twice atmospheric
pressure, the change of this length after removal of the force is at least 90%
to 110% of
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the original length. This can for example be measured by use of Perkin-Elmer
DMA 7e
equipment.
Similarly, the matrix is preferably flexible to such an extend that when a
matrix sample
S having a cross section of a specific length, for example 1 cm, is stretched
with a static
force applied along the axis of that cross section, the static force being
variable, but at
least equivalent to twice atmospheric pressure, the change of this length
after removal of
the force is at least 90% to 110% of the original length. This can for example
be
measured by use of Perkin-Elmer DMA 7e equipment.
In particular, when using this equipment, the static forces applied along the
axis of a cross
section of a 1 cm3 matrix sample are gradually increased until the deformation
of the
component, in the direction of the cross section, is 70%. Then, the force is
removed and
the final deformation of the matrix sample in the direction of the cross
section is
1 S measured. Preferably, this length of the cross section after this
experiment is preferably
from 90% to 110% of the original length of the cross section, preferably from
95% to
105% or even from 98% to 100%.
The elastic modulus or Young's modulus is related to the relative density,
namely
Ex
- P
Es ~ Ps
where p* is the relative density of the matrix or even the component, and p5
is the relative
densities of the components of the matrix or component, as described herein,
and E* is
the Young's modulus of the matrix or even the component itself, and ES that of
the
components of the matrix or even the component. This means that even a stiff
polymeric
material, with a high ES can be made into an elastic, flexible matrix by
adjusting the
levels and/ or type of plasticiser and optionally by modifying the density (or
for example
by introducing gas during the making process to form foam component, as
described
below).
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The matrix, or even the component as a whole, is in the form of a foam and
preferably
such that it forms an interconnected network of open and/ or closed cells, in
particular a
network of solid struts or plates which form the edges and faces of open and/
or closed
cells. The spacing inside the cells can contain part of the active ingredient
and/ or a gas,
such as air.
Preferably, the ratio of the closed cells to open cells in the matrix of the
component, or
the component as a whole is more than 1:1, preferably more than 3:2 or even
more than
2:1 or even more than 3:1. This ratio can be determined by calculating the
Total Volume
of a specimen of the matrix or component, VT , (assuming a spherical shape),
and then
measuring with a Mercury Porosimetry Test method the Open Cell Volume (Vo) and
subtracting the Open Cell Volume from the Total Volume should deliver the
Closed Cell
Volume (V~: VT = Vo + V~).
Polymeric material
Any polymeric material can be used to form the matrix herein, preferably the
polymeric
material has itself a Tg as described above or more typically, it can be
formed into a
matrix having the Tg as described above by using a suitable amount of
plasticiser.
Preferably, the polymer material comprises or consists of amorphous
polymer(s).
The polymeric material may consist of a single type of homologous polymer or
may be a
mixture of polymers. Mixtures of polymers may in particular be beneficial to
control the
mechanical and/or dissolution properties of the component, depending on the
application
thereof and the requirements thereof.
Preferred it that the polymeric material comprises a water-dispersible or more
preferably
a water-soluble polymer. Water-dispersible and water-soluble are typically
defined as
described hereinbefore, as per the method for determining the water-solubility
and water-
dispersibility of the component herein. Preferred water-dispersible polymers
herein have
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a dispersibility of at least 50%, preferably at least 75% or even at least
95%, as measured
by the method set out hereinbefore using a glass-filter with a maximum pore
size of 50
microns; more preferably the polymer herein is a water-soluble polymer which
has a
solubility of at least 50%, preferably at least 75% or even at least 95%, as
measured by
the method set out hereinbefore using a glass-filter with a maximum pore size
of 20
microns.
The polymer can have any average molecular weight, preferably from about 1000
to
1,000,000, or even form 4000 to 250,000 or even form 10,000 to 200,000 or even
form
20,000 to 75,000. Highly preferred may be polymeric material having a weight
average
molecular weight of from 30,000 to 70,000.
Depending on the required properties of the component herein, the polymeric
material
can be adjusted. For example, to reduce the solubility, polymers may be
included in the
material, which have high molecular weights typically above 50,000 or even
above
100,000, and vice versa. For example, to change the solubility, polymers of
varying level
of hydrolyses may be used. For example, to improve (reduce) the elastic
modulus, the
cross-linking of the polymers may be increased and/ or the molecular weight
may be
increased.
It may be preferred that the polymer used in the component herein has a
secondary
function, for example a function in the composition wherein component is to be
incorporated. Thus, for example, for cleaning products, it is useful when the
polymer in
the polymeric material is a dye transfer inhibiting polymer, dispersant etc.
Preferred are polymers selected from polyvinyl alcohols and derivatives
thereof,
polyethylene glycols and derivatives thereof, polyvinyl pyrrolidone and
derivatives
thereof, cellulose ethers and derivatives thereof, and copolymers of these
polymers with
one another or with other monomers or oligomers. Most preferred are PVP (and
derivatives thereof) and/ or PEG (and derivatives thereof) and most preferably
PVA (and
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derivatives thereof) or mixtures of PVA with PEG and/ or PVP (or derivatives
thereof).
Most preferred may also be a polymeric material only comprising PVA.
Preferably, such polymers have a level of hydrolysis of at least 50%, more
preferably at
least 70% or even from 85% to 95%.
Plasticiser
Any plasticiser which is suitable to aid the formation of a matrix as defined
herein can be
used. Mixtures of plasticiser may also be used.
Preferably, the plasticiser or at least one of the plasticisers, has a boiling
point above
40°C, preferably above 60°C, or even above 95°C, or even
above 120°C, or even above
150°C.
Preferred plasticisers include glycerol or glycerine, glycol derivatives
including ethylene
glycol, digomeric polyethylene glycols such as diethylene glycol, triethylene
glycol and
tetraethylene glycol, polyethylene glycol with a weight average M.W. of below
1000,
wax and carbowax, ethanolacetamide, ethanolformamide, triethanolamine or
acetate
thereof, and ethanolamine salts, sodium thiocyanates, ammonium thiocyanates,
polyols
such as 1,3-butanediol, sugars, sugar alcohols, ureas, dibutyl or dimethyl
pthalate, oxa
monoacids, oxa diacids, diglycolic acids and other linear carboxylic acids
with at least
one ether group distributed along the chain thereof, water or mixtures
thereof.
Preferably, when water is used, an additional plasticiser is present. If water
is used, then
the water is typically present in the foam component at a level of at least 3
wt%,
preferably more than 3 wt%, preferably even at least 5 wt%, or even at least
10 wt%.
The plasticiser is preferably present at a level of at least 0.5% by weight of
the article,
preferably by weight of the matrix, provided that when water is the only
plasticiser it is
present at a level of at least 3% by weight of the component, or preferably by
weight of
the matrix.
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Preferably, the plasticiser is present at a level of 1% to 35% by weight of
the article or
matrix, more preferably 2% to 25% or even to 15% or even to 10% or even to 8%
by
weight of the article or by weight of the matrix. The exact level will depend
on the
polymeric material and plasticiser used, but should be such that the matrix of
the article
has the desired Tg. For example, when urea is used, the level is preferably 1
% to 10% by
weight of the matrix, while when glycerine or ethylene glycol or other glycol
derivatives
are used, higher levels may be preferred, for example 2% to 15% by weight of
the
component or matrix.
Active ingredient
The active ingredient can be any material which is to be delivered to a liquid
environment, or preferably an aqueous environment and preferably an ingredient
which is
active in an aqueous environment. For example, when used in cleaning
compositions the
component can contain any active cleaning ingredients. The component may also
comprise compositions, such as cleaning composition or personal care
compositions.
In particular, it is beneficial to incorporate in the component, active
ingredients which are
moisture sensitive or react upon contact with moisture, or solid ingredients
which have a
limited impact robustness and tend to form dust during handling.
The active ingredient is typically a moisture sensitive ingredient, a
temperature sensitive
ingredient, an oxidizeable ingredient, a volatile ingredient, or a combination
thereof. The
active ingredient may be biological viable material, hazardous or toxic
material an
agricultural ingredient such as an agrochemical, a pharmaceutical ingredient
such as a
medicine or drug, or a cleaning ingredient.
In particular preferred in component are active ingredients, such as enzymes,
perfumes,
bleaches, bleach activators, fabric cationic and/or silicone softeners and/or
conditioners,
antibacterial agents, brighteners, photo-bleaches and mixtures thereof.
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Another active ingredient is a perhydrate bleach, such as metal perborates,
metal
percarbonates, particularly the sodium salts. Also preferred active
ingredients are organic
peroxyacid bleach precursor or activator compound, preferred are alkyl
percarboxylic
precursor compounds of the imide type include the N-,N,N1N1 tetra acetylated
alkylene
diamines wherein the alkylene group contains from 1 to 6 carbon atoms,
particularly
those compounds in which the alkylene group contains 1, 2 and 6 carbon atoms
such as
tetraacetyl ethylene diamine (TAED), sodium 3,5,5-tri-methyl
hexanoyloxybenzene
sulfonate (iso-NOBS), sodium nonanoyloxybenzene sulfonate (NOBS), sodium
acetoxybenzene sulfonate (ABS) and pentaacetyl glucose, but also amide
substituted
alkyl peroxyacid precursor compounds
Highly preferred active ingredient for use in the component herein are one or
more
enzymes. Preferred enzymes include the commercially available lipases,
cutinases,
amylases, neutral and alkaline proteases, cellulases, endolases, esterases,
pectinases,
lactases and peroxidases conventionally incorporated into detergent
compositions.
Suitable enzymes are discussed in US Patents 3,519,570 and 3,533,139.
Preferred
commercially available protease enzymes include those sold under the
tradenames
Alcalase, Savinase, Primase, Durazym, and Esperase by Novo Industries A/S
(Denmark),
those sold under the tradename Maxatase, Maxacal and Maxapem by Gist-Brocades,
those sold by Genencor International, and those sold under the tradename
Opticlean and
Optimase by Solvay Enzymes. Preferred amylases include, for example, a-
amylases
obtained from a special strain of B lieheniformis, described in more detail in
GB-
1,269,839 (Novo). Preferred commercially available amylases include for
example, those
sold under the tradename Rapidase by Gist-Brocades, and those sold under the
tradename
Termamyl, Duramyl and BAN by Novo Industries A/S. Highly preferred amylase
enzymes maybe those described in PCT/ US 9703635, and in W095/26397 and
W096/23873. The lipase may be fungal or bacterial in origin being obtained,
for
example, from a lipase producing strain of Humicola sp., Thermomyces sp. or
Pseudomonas sp. including Pseudomonas pseudoalcali eg nes or Pseudomas
fluorescens.
Lipase from chemically or genetically modified mutants of these strains are
also useful
CA 02385161 2002-03-18
WO 01/25322 PCT/US00/27332
herein. A preferred lipase is derived from Pseudomonas pseudoalcali enes,
which is
described in Granted European Patent, EP-B-0218272.
Another preferred lipase herein is obtained by cloning the gene from Humicola
lanu~inosa and expressing the gene in Asper y'g llus oryza, as host, as
described in
European Patent Application, EP-A-0258 068, which is commercially available
from
Novo Industri A/S, Bagsvaerd, Denmark, under the trade name Lipolase. This
lipase is
also described in U.S. Patent 4,810,414, Huge-Jensen et al, issued March 7,
1989.
Dissolution aid
The component of the invention comprises a dissolution aid.
The dissolution aid is in addition to the active ingredient of the component
herein. If more
than one active ingredient is comprised by the component herein, then it may
be preferred
that one of the active ingredients is selected such that is, or acts as, a
dissolution aid. For
the purpose of the present invention, the dissolution aid is always an
additional ingredient
of the component herein to the active ingredient of the component herein.
Therefore, for the purpose of the present invention, for a component to be
defined as
comprising a dissolution aid and an active ingredient, wherein said component
comprises
an ingredient having dual functionality and can function as an active
ingredient or a
dissolution aid as defined herein, an additional dissolution aid or active
ingredient must
be present in the article herein, which is in addition to the ingredient
having dual
functionality, to obtain a component comprising an active ingredient and a
dissolution aid
which is in accord with the present invention.
The above statements with regard to ingredients having dual functionality are
also true
when considering other embodiments of the present invention. It is essential
for the
component herein to comprise an active ingredient, a polymeric material and a
plasticiser
(which form the matrix), and a dissolution aid. Thus, to obtain a component in
accord
with the present invention, at least four different ingredients must be
present in said
16
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WO 01/25322 PCT/US00/27332
component. It may be preferred to select essential ingredients which have dual
functionality.
The above statements with regard to dual functionality ingredients are also
true when
considering highly preferred embodiments of the present invention, for example
preferred
components comprising additional ingredients such as a stabilising aid.
The dissolution aid may preferably comprise a sulfonated compound such as C,-
C4
alk(en)yl sulfonates, C,-C4 aryl sulfonates, di iso butyl benzene sulphonate,
toluene
sulfonate, cumene sulfonate, xylene sulfonate, salts thereof such as sodium
salts thereof,
derivatives thereof, or combinations thereof, preferably di iso butyl benzene
sulphonate,
sodium toluene sulfonate, sodium cumene sulfonate, sodium xylene sulfonate,
and
combinations thereof.
The dissolution aid may comprise a C~-C4 alcohol such as methanol, ethanol,
propanol
such as iso-propanol, and derivatives thereof, and combinations thereof,
preferably
ethanol and/or iso-propanol.
The dissolution aid may comprise a C4-Cep diol such as hexanediol and/or
cyclohexanediol, preferably 1,6-hexanediol and/or 1,4-cyclohexanedimethanol.
The dissolution aid may comprise compounds which are capable of acting as
whicking
agents, such as cellulosic based compounds, especially modified cellulose.
The dissolution aid may comprise swelling agents such as clays. Preferred
clays are
smectite clays, especially dioctahedral or trioctrahedral smectite clays.
Highly preferred
clays are montmorillonite clay and hectorite clay, or other clays found in
bentonite clay
formations.
The dissolution aid preferably comprises an effervescence system. A preferred
effervescence system comprises an acid source capable of reacting with an
alkali source
17
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in the presence of water to produce a gas. The gas produced by this
interaction, includes
nitrogen, oxygen and carbon dioxide gas. The acid source may be any organic,
mineral or
inorganic acid, or a derivative thereof, or a mixture thereof. Preferably the
acid source
comprises an organic acid. Suitable acid sources include citric, malic,
malefic, fumaric,
aspartic, glutaric, tartaric succinic or adipic acid, monosodium phosphate,
boric acid, or
derivatives thereof. Citric acid, malefic or malic acid are especially
preferred.
As discussed hereinbefore, the effervescence system preferably comprises an
alkali
source, however, for the purpose of the invention, it should be understood
that the alkali
source may be part of the component or can be part of a composition comprising
the
component, or can be present in the washing liquor, whereto the component, or
a
composition comprising the component, is added. Any alkali source which has
the
capacity to react with the acid source to produce a gas may used herein.
Preferred alkali
sources can be perhydrate bleaches, including perborate, and silicate
material.
Preferably the gas is carbon dioxide, and therefore the alkali source is a
preferably a
source of carbonate, which can be any source of carbonate known in the art. In
a
preferred embodiment, the carbonate source is a carbonate salt. Examples of
preferred
carbonates are the alkaline earth and alkali metal carbonates, including
sodium or
potassium carbonate, bicarbonate and sesqui-carbonate and any mixtures thereof
with
ultra-fine calcium carbonate such as are disclosed in German Patent
Application No.
2,321,001 published on November 15, 1973. Alkali metal percarbonate salts are
also
suitable sources of carbonate species, which may be present combined with one
or more
other carbonate sources.
The molecular ratio of the acid source to the alkali source present in the
component is
preferably from 50:1 to 1:50, more preferably from 20:1 to 1:20 more
preferably from
10:1 to 1:10, more preferably from 5:1 to 1:3, more preferably from 3:1 to
1:2, more
preferably from 2:1 to 1:2.
Additional Ingredients
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The component of the invention preferably comprises additional ingredients
which can
improve the stability of the active ingredient of the article herein.
These additional ingredients are typically capable of stabilising the active
ingredient of
the component herein, this is especially preferred when the active
ingredients) comprise
an oxidative or moisture sensitive active ingredient, such as one or more
enzymes. These
additional ingredients may also stabilise the matrix of the component herein,
and thus
indirectly stabilise the active ingredient. These stabilising ingredients are
defined herein
as "stabilising agents".
The stabilising agent is preferably a compound which stabilises the active
ingredient, or
matrix, from oxidative and/or moisture degradation during storage. The
stabilising agent
may be, or comprise, a foam matrix stabiliser. The stabilising agent may be,
or comprise,
an active ingredient stabiliser, especially an enzyme stabiliser. Stabilising
agents which
are capable of stabilising the active ingredient indirectly by keeping the
foam matrix of
the article stable, herein referred to as "foam stabiliser".
Foam stabilisers preferably comprise a surfactant such as a fatty alcohol,
fatty acid,
alkanolamide, amine oxide, or derivatives thereof, or combinations thereof.
The foam
stabiliser may comprise betaine, sulfobetaine, phosphine oxide, alkyl
sulfoxide,
derivatives thereof, or combinations thereof.
Other preferred foam stabilisers comprises one or more anions or cations such
as mono-,
di-, tri- valent, or other multivalent metal ions, preferred are salts of
sodium, calcium,
magnesium, potassium, aluminium, zinc, copper, nickel, cobalt, iron, manganese
and
silver, preferably having an anionic counterion which is a sulphate,
carbonate, oxide,
chloride, bromide, iodide, phosphate, borate, acetate, citrate, and nitrate,
and
combinations thereof.
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The foam stabiliser may comprise finely divided particles, preferably finely
divided
particles having an average particle size of less than 10 micrometers, more
preferably less
than 1 micrometer, even more preferably less than 0.5 micrometers, or less
than 0.1
micrometers. Preferred finely divided particles are aluminosilicates such as
zeolite, silica,
or electrolytes described hereinbefore being in the form of finely divided
particles.
The foam stabiliser may comprise agar-agar, sodium alginate, sodium dodecyl
sulfate,
polyethylene oxide, guar gum, polyacrylate, or derivatives thereof, or
combinations
thereof.
The foam stabiliser may be coating which is separate to the matrix of the
article herein.
The foam stabiliser typically partially encloses, preferably completely
encloses, the
article herein or the active ingredient thereof.
The coating is typically contacted to, preferable in such a manner as to form
a coat on, the
active ingredient prior to said active ingredient being contacted to the
polymeric material
or the plasticiser of the matrix, and preferably being incorporated in the
article herein.
The coating may typically be contacted to, preferable in such a manner as to
form a coat
on, the article herein subsequent to the polymeric material and the
plasticiser forming the
matrix, and preferably subsequent to the active ingredient contacting said
matrix or being
incorporated in the article herein.
Preferred coating comprises polymers, typically selected from polyvinyl
alcohols and
derivatives thereof, polyethylene glycols and derivatives thereof, polyvinyl
pyrrolidone
and derivatives thereof, cellulose ethers and derivatives thereof, and
copolymers of these
polymers with one another or with other monomers or oligomers. Most preferred
are PVP
(and derivatives thereof) and/ or PEG (and derivatives thereof) and most
preferably PVA
(and derivatives thereof) or mixtures of PVA with PEG and/ or PVP (or
derivatives
thereof). These polymers do not form the matrix of the article herein. Thus,
these
polymers are different to the polymeric materials of the foam matrix.
CA 02385161 2002-03-18
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A preferred coating comprises compounds such as glycerol or glycerine, glycol
derivatives including ethylene glycol, digomeric polyethylene glycols such as
diethylene
glycol, triethylene glycol and tetraethylene glycol, polyethylene glycol with
a weight
average M.W. of below 1000, wax and carbowax, ethanolacetamide,
ethanolformamide,
triethanolamine or acetate thereof, and ethanolamine salts, sodium
thiocyanates,
ammonium thiocyanates, polyols such as 1,3-butanediol, sugars, sugar alcohols,
ureas,
dibutyl or dimethyl pthalate, oxa monoacids, oxa diacids, diglycolic acids and
other linear
carboxylic acids with at least one ether group distributed along the chain
thereof, water or
mixtures thereof. These compounds do not form the foam matrix of the article
herein.
Thus, these compounds are different to the plastisicer of the foam matrix.
Preferred stabilising agents that are capable of stabilising the active
ingredient directly,
especially if said active ingredient comprises one or more enzymes, are
defined herein as
1 S "active stabilisers" or "enzyme stabilisers". Typically active stabilisers
interact directly
with, and stabilise, the active ingredient.
Typical active stabilisers for use herein preferably comprise a surfactant.
Suitable
surfactants for use herein are those described hereinbefore as surfactants
suitable for use
as matrix stabilisers. In addition to these surfactants, other surfactants
suitable for use
herein may comprise surfactants such as sodium alky(en)yl sulfonates, sodium
alkoxysulfonates, preferred alkoxysulfonates are those comprising from 10 to
18 carbon
atoms in any conformation, preferably linear, and having an average
ethoxylation degree
of from 1 to 7, preferably from 2 to 5.
Other preferred active stabilisers comprise boric acid, formic acid, acetic
acid, and salts
thereof. These acid salts preferably comprise counerions such as calcium
and/or sodium.
Preferred active stabilisers comprise cations such as calcium and or sodium.
Preferably
calcium chloride and/or sodium chloride.
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Other preferred active stabilisers comprise small peptide chains averaging
from 3 to 20,
preferably from 3 to 10 amino acids, which interact with and stabilise the
active
ingredient, especially enzyme(s).
Other active stabilisers comprise small nucleic acid molecules, typically
comprising from
3 to 300, preferably from 10 to 100 nucleotides. Typically nucleic acid
molecules are
deoxyribonucleic acid and ribonucleic acid. The nucleic acid molecules may be
in the
form of a complex with other molecules such as proteins, or may form a complex
with the
active ingredient of the article herein, especially enzyme(s).
Active stabilisers suitable for use herein, especially when the article herein
comprises a
bleach, comprise anti-oxidants and/or reducing agents such as thiosulphate,
methionine,
urea, thiourea dioxide, guanidine hydrochloride, guanidine carbonate,
guanidine
sulfamate, monoethanolamine, diethanolamine, triethanolamine, amino acids such
as
glycine, sodium glutamate, proteins such as bovine serum albumin and casein,
tert-
butylhydroxytoluene, 4-4,-butylidenebis (6-tert-butyl-3-methyl-phenol), 2,2'-
butlidenebis
(6-tert-butyl-4-methylphenol), (monostyrenated cresol, distyrenated cresol,
monostyrenated phenol, distyrenated phenol, 1,1-bis (4-hydroxy-phenyl)
cyclohexane, or
derivatives thereof, or a combination thereof.
Other active stabilisers may comprise a reversible inhibitor of the active
ingredient.
Without wishing to be bound by theory, it is believe that a reversible
inhibitor of the
active ingredient, especially if the active ingredient comprises one or more
enzymes, may
form a complex with, and improve the stability of, said active ingredient, and
thus,
stabilises the active ingredient during storage. When the active ingredient is
released,
typically into a liquid environment, the reversible inhibitor dissociates from
the active
ingredient and the active ingredient is then able to perform the desired
action it is
designed or intended to perform.
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Active stabilisers suitable for use herein may comprise sugars, Typical sugars
for use
herein include those selected from the group consisting of sucrose, glucose,
fructose,
raffinose, trehalose, lactose, maltose, derivatives thereof, and combinations
thereof.
The active stabiliser may also comprise sugar alcohols such as sorbitol,
mannitol,
inositol, derivatives thereof, and combinations thereof.
It may be preferred that the active stabiliser is in the form of a coating or
barrier which at
least partially encloses the article herein or the active ingredient thereof,
preferably
completely encloses the article herein or the active ingredient thereof,
especially an
enzyme.
Process for making foam component
The component of the invention can be made by any process of making a polymer
matrix
of the defined Tg from a polymeric material and a plasticiser, and combining
an active
ingredient and a stabilising agent with such a matrix. Preferred processes
involve
chemically or physically introducing a gas in a mixture of the polymeric
material and
plasticiser and optionally the active ingredient.
A preferred process for making the component herein comprising the step of
a) obtaining a mixture of a polymeric material and a plasticiser, preferably
water
and an additional plasticiser;
b) chemically or physically introducing gas in said mixture of polymeric
material and water;
c) prior to step b) and/or simultaneously with step b) and/ or subsequently to
step b), addition of the active ingredient to said mixture;
d) prior to step c) and/or simultaneously with step c) and/ or subsequently to
step c), contacting a dissolution aid to said mixture;
e) shaping the articles of the resulting mixture;
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WO 01/25322 PCT/US00/27332
whereby one or more of steps a) to e) are followed or accompanied by removal
of
part of the water, if present.
In step a) the mixture is preferably an aqueous mixture or slurry and after or
in step b), c)
and/ or d), part of the water is removed such that the resulting component
comprises 3%
by weight of free-moisture, or more.
Step c) preferably comprises the step of obtaining a body comprising the
active ingredient
or part thereof and enclosing said body with the mixture of step b).
Step d) preferably comprises the step of mixing, more preferably intimately
mixing or
enclosing, the active ingredient with the stabilising agent prior to
contacting said
stabilising agent, and preferably said active ingredient, to said mixture.
Preferably, the component comprises open and/ or closed cells and the process
comprising the steps of
a) formation of a mixture of the polymeric material, the active material, a
dissolution aid, a plasticiser and a liquid, whereby the liquid and the
plasticiser
may be the same compound;
b) shaping of bodies from the mixture of claim b) and
c) evaporation of the liquid or part thereof to form spacings in the mixture
which
form the inner area of the cells of the component,
whereby step c) is preferably conducted by freeze drying or by heating the
bodies,
thereby causing the liquid or part thereof to evaporate.
Step b) may also be conducted by submitting the mixture of a) to pressure,
preferably
under mixing and/ or increasing the temperature, and subsequently removing the
pressure
or part thereof, thereby causing the liquid to evaporate. For example, an
extrusion process
can be used. Hereby it is preferred that the mixture of the polymeric
material, plasticiser,
preferably including water, and optionally the active ingredient and/or
dissolution aid, is
introduced in an extruder, wherein the mixture is further mixed and heated,
due to the
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WO 01/25322 PCT/US00/27332
mixing or due to applying heat, preferably such that the mixture therein forms
a melt, and
then dropping the pressure at the exit point where the extruded mixture (which
can be
formed into the desired form, for example granules) exits the extruder,
whereby the liquid
or part thereof evaporates, or preferably the water evaporates as steam from
the extruded
S mixture. This results in formation of cells with spacings, as described
above, which then
may contain a gas, preferably air, and optionally the active ingredient. These
spacings
form the internal area of the cells of the matrix of the component of the
invention.
Step b) in the process may also be conducted by heating the mixture to cause
the liquid or
part thereof to evaporate, resulting in the formation of spacings, as above.
This can
preferably done by feeding the mixture into a spray drying tower, preferably
such that the
mixture is fed through spray nozzles which form droplets of the mixture, and
spray drying
the droplets at conventional temperature, resulting in the component.
The physical and/ or chemical introduction of gas or foaming, as mentioned
above can be
done by any known method, preferred are
- physical foaming by gas injection (dry or aqueous route) optionally under
mixing, high shear stirring (dry or aqueous route), gas dissolution and
relaxation
including critical gas diffusion (dry or aqueous route);
- chemical foaming by in-situ gas formation (via chemical reaction of one or
more
ingredients, including formation of COZ by an effervescence system),
- steam blowing, LJV light radiation curing.
These foaming steps are preferably followed by a drying step or an additional
drying step
to remove excess liquid or part thereof, such as water. In particular, the
drying step is at
least done after the polymer matrix is formed, and optionally after the active
ingredient is
added, preferably as final step in the process. The drying step is done
preferably such
that the final component is of about the same volume after the drying step as
before the
drying step. Thereto, the drying step is preferably done by freeze-drying,
whereby the
solvent, e.g. water, is removed under vacuum and reduced temperatures. Also
useful can
CA 02385161 2002-03-18
WO 01/25322 PCT/US00/27332
be slow fluid bed drying or oven drying at modestly increased temperatures,
such as 40-
80°C, or even 40-60°C .
Preferred processes involve at least the step of formation of a mixture of
polymeric
material and a liquid, preferably a solution of polymeric material and a
solvent, preferably
comprising water, and adding a plasticiser (or as the case may be, additional
plasticiser)
to this. If the presence of the active ingredient and/or the dissolution aid
in the matrix is
required, these are also added to the mixture of polymeric material solvent
and plasticiser.
Alternatively, or in addition, it may be preferred that the matrix is formed
around the
active material, preferably a core of the active material and carrier
material.
Preferred means of incorporating the dissolution aid into the component herein
include;
a) contacting, preferably incorporating therein, a dissolution aid to a dry
foam component
to obtain a foam component in accord with the present invention, e.g. this can
be for
example by injecting, or enclosing the matrix of the component; and/or
b) cooling the foam component to a temperature near, preferably just above, to
said foam
components freezing point, and subsequently contacting or incorporating the
dissolution
aid to said foam component to obtain a foam component in accord with the
present
invention; and/or
c) as b), followed by freezing said foam component, for example prior to
freeze drying;
and/or
d) partially coating, or preferably coating, the dissolution aid with a
material such as cetyl
alcohol.
This is than further processed for example into bodies of the shape of the
final
component, for example particles or beads, and typically dried to obtain the
components.
Preferably, a gas is added prior to the shaping step. Shaping steps include
granulation
steps such as atomisation or spray-drying, extrusion, micro pastillisation.
Freeze drying
is a preferred process to dry the bodies to form the components.
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The following are preferred processes resulting in low dust or even nil dust
particles, as
measured with the stressed Heubach test described below, having a matrix with
a Tg of
below 10°C and an elastic modulus of below O.SGNrri 2, as indicated in
more detail in the
following specific examples.
A first preferred process is as follows:
The required amount of a solution of the polymer material (or a mixture of
polymer and a
liquid) is obtained, and for example (introduced) in a mix tank. Then the
required amount
of (a solution of) the active material, for example an enzyme solution, and
dissolution aid
is added, and the required amount of plasticiser is added, and optionally
other additional
ingredients, such as fillers, densification agents etc. This is agitated to
become a
homogeneous mixture. Preferably, a gas such as air can be introduced into the
solution,
by any of the methods above, preferably physically, by high sheer mixing.
Then, particles are formed from this mixture by atomisation, preferably using
a Positive
Displacement pump to transfer the mixture solution to a spray nozzle (s),
preferably using
either single or mufti-fluid nozzles to create liquid droplets.
The liquid droplets are then frozen, preferably by passing through a
refrigeration media
(can include liquid nitrogen, freon, refrigeration oils). Then, the frozen
particles are
transferred to a vacuum chamber, preferably having a temperature (as measured
on the
surface of the particles) below 0°C.
The frozen particles are preferably collected from the spray column and
transferred
without raising the temperature. The temperature of the walls and contact
trays of the
freeze dryer are preferably maintained below 0°C to keep the particles
frozen.
A vacuum is applied, and the frozen ice crystals will sublimate a gas form,
resulting in
cells in the particle. The total drying degree can be controlled with the
level of vacuum,
and contact temperature of the chamber walls and trays.
After the particles have been dried to the desired moisture content, they will
be free
flowing. Then preferably, the particles can be classified via a variety of
screens and or
process equipment.
The optional step above, of introducing gas (bubbles) into the polymeric
solution mixture
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WO 01/25322 PCT/LTS00/27332
has been found to give a much better impact resistance to the particle,
reflected by its
electric modules. The introduction of gas bubbles can be accomplished in a
variety of
ways.
In the atomisation step, the atomizing nozzle should preferably be located in
a spray
column with sufficient height to accomplish droplet freezing while gravity
falling. The
nozzle type can be of various designs - single fluid pressure nozzle, spinning
insert, sonic,
or multi-fluid nozzle. The important aspect is to disrupt the liquid stream to
form
discrete liquid droplets. As these droplets fall with gravity, they need to be
cooled to
freezing. The freezing media is preferably non-aqueous gas or liquid which can
provide
rapid freezing of the liquid droplets. The actual temperatures for cooling
these droplets
to form particles, is preferably below 0°C and preferably below -
20°C.
It may also be preferred that the above process is modified as follows:
a gas, preferably COZ gas, is introduced in the mixture and the mixture is
introduced in a
spray drying tower, as above, thereby forming spray-dried foamed particles,
which can be
classified if necessary. Preferably the inlet temperature in the tower is
about 130°C and
the outlet temperature about 75°C and the spray rate is l2.Sg/min. For
example a Niro
Mobil Minor with two fluid nozzles can be used hereby. The resulting particle
may be
already of the required form, or may be submitted to further freeze drying
under vacuum.
Another preferred process is as follows:
The required amount of a solution of the polymer material is obtained (or
alternatively, a
powdered polymer can be used provided a liquid is added) and for example
introduced in
a mix tank. Then the required amount of plasticiser is added, and optionally
other
additional ingredients, such as fillers, densification agents etc. This is
agitated to become
a homogeneous mixture. Preferably, a gas such as air can be introduced into
the solution,
by any of the methods above, preferably physically, by high sheer mixing.
Also, particles comprising the active ingredient, such as an enzyme, and the
dissolution
aid, and optionally other ingredients, such as fillers or carriers are
prepared, for example
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WO 01/25322 PCT/US00/27332
by fluid bed coating, by charging first 'cores' (typically when the actives
care enzymes,
these core particles are sugar or starch particles), to a fluid bed and
spraying the active
material or a solution of the active material onto these cores and then drying
any solvent
such as water from the active solution off with warm fluidizing air.
Then, the polymeric mixture above is introduced onto these active/cores , for
example via
a positive displacement pump leading to an atomizing nozzle inside the fluid
bed as
described above. More than one nozzle can be used and it may be preferred that
different
ingredients are added to the core via different nozzles.
The fluidizing air needs is preferably below 0°C, preferably around -
20°C. Then, the
fluidizing air freezes the polymeric mixture/solution onto the outside of the
active-core.
This is a critical parameter to control and typically the air temperature must
be below 0°C
in order to quickly freeze the polymeric mixture/solution onto the core
particles.
Then preferably, the frozen particles thus obtained are transferred to a
vacuum chamber,
as above, and also classification may take place.
This technology results in particle of the invention comprising a matrix
around the active
ingredient.
The optional step above, of introducing gas (bubbles) into the polymeric
solution mixture
has been found to give a much better impact resistance to the particle,
reflected by its
Young's Modulus.
Another preferred process is as follows:
The required amount of a solution of the polymer material (or solid polymer
and a
suitable amount of liquid) is obtained, and for example introduced in a mix
tank. Then
the required amount of (a solution of) the active material, for example an
enzyme
solution, and a dissolution aid (a solution of) is added (into the mix tank)
and the required
amount of plasticiser is added, and optionally other additional ingredients,
such as fillers,
densification agents. This is agitated to become a homogeneous mixture.
Preferably, a gas
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WO 01/25322 PCT/US00/27332
such as air can be introduced into the solution, by any of the methods above,
preferably
physically, by high sheer mixing.
Then, the polymeric solution is pumped from the mix tank into an extruder or
into a
cavity with a die plate at the end. Before entering the extruder or cavity,
gas can be
injected into the mixture and for example be dispersed via a mechanical shear
mixer or a
static mixer.
As the extrudate exits the die plate, the change in pressure creates a slight
puffing or
swelling in the extrudate. The extrudate is then cut to the correct length
with either a die
face cutter or with some other device (e.g. heated wire, rotating plug cutter,
etc.). The
extrudates can optionally go through additional rounding steps to become more
spherical.
Process equipment that can accomplish this function include (rotating pans,
agglomeration pans, marumerizers, tumbling drums, mixing drums, etc.).
For example, a paste is prepared by mixing 75g PVOH, 15g Citric acid, 2g PEO
and
22.5g glycerol in a Braun mixer, high sheer, namely set at full speed for
40seconds: then
80g H20 and 80g enzyme was added and mixed at high sheer, namely set at full
speed
until a smooth foam had formed, approximately within 2mins. The foam was
extruded
from a l Oml syringe onto a plastic sheet. This was left for 24 hours to dry.
Once dry the
foam strips were cut into approximately 1 - 2mm sections to form particles of
the formula
(dry) 63.2 polyvinyl alcohol, 19% glycerol, 12.7% citric acid, 1.6% PEO, 4%
water,
3.2% enzyme.
The resulting particles had an elastic modulus of 0.00016GN.rri 2.
The resulting particles give 0% dusting when tested in a stressed Heubach
test, which
indicated a very good impact robustness. (The stressed Heubach test is
performed as
known in the art, using equipment as supplied by Heubach Engineering GMbH,
Germany, with the stressed modification of the rotation speed of the impeller
being 75 ~
1 rpm and the balls being of Tungsten carbide and 82 grams each.).
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Preferred moulding-/ pastillisation process:
A highly preferred process involves shaping particles of mixtures as described
above by
use of a mould: whereby mixtures as described herein are introduced in a mould
and
subsequently dried (freeze dried). Also preferred is such a process which uses
pastille
making equipment, whereby mixtures as described above, preferably comprising
also
introduced gas, are forced through a rotating perforated drum onto a moving
conveyor
belt, shaping into pastilles (droplets or particles). When dry or hardened,
the thus formed
particles or beads are removed from the conveyor belt by a scraper.
Preferably, the first step is to make a mixture of polymeric material and
plasticiser, a
liquid component, and optionally the active ingredient and dissolution aid.
Preferably, gas
is introduced into this mixture as described herein. This must preferably be
free from
large undissolved particles which may block up the perforations in the drum.
The mixture
is preferably in the temperature range 0-50°C. The mixture is pumped
into a manifold
that enters the rotating perforated drum and is parallel to the longitudinal
axis of the
drum. The mixture is pumped into the inner of the drum and, as the drum
rotates, is
brought into contact with an internal scraper bladed lying in contact and
along the length
of the inner surface of the perforated drum, parallel to the feed manifold.
The distance of the outside surface of the perforated drum is within the
height of the
desired particle height (which is less than the diameter of the perforations)
but not
touching a moving conveyor belt or a rotating smooth surfaced drum at the
point where
the internal scraper is in contact with the inner surface of the perforated
drum, the
tangential speed of the perforated drum matched by the speed of the conveyor
belt or the
tangential speed of the smooth surfaced drum. As the mixture is forced through
the
perforations, which are typically in the size range 300 - 2000pm (but may be
smaller or
larger), it is deposited onto the surface below. The rotation of the
perforated drum shears
the feed material away from the material on the smooth surface thus leaving a
droplet, or
pastille, which will form the required particle. These pastilles can be set by
either chilling
or by evaporation of some or all of the solvent fluid. If chilling is required
the
temperature of the conveyor belt or smooth surfaced drum may be in the range
ambient to
-20°C. If evaporation of a solvent is required, then this can be
achieved by heat
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conduction from the conveyor belt which may be in the range ambient to
70°C, by drying
air (which may be heated up to 200°C to reduce drying time) passing
over the surface of
the pastilles, or both.
Then, they resulting particles are removed from the drum or conveyor belt by a
scraper.
This removal process may be improved by the use of a suitable lubricant
(release agent)
on the drum, such as silicone oil. This lubricant or release agent may show an
added
benefit to the particle by reducing adhesive properties between the polymeric
mixture and
the belt/drum and thus increasing the pastille height, if this is a desirable
feature.
Examples
Example 1
A process of preparing a foam component in accord with the present invention
4700g of a 33%w/w solution of polyvinyl alcohol (weight average M.W being from
30,000 to 70,000) is mixed with 3360g enzyme solution (5% by weight active
enzyme
and 85% by weight water), 159.3g of glycerol and 155g of cyclohexane
dimethanol in a
high shear mixer until a smooth foam is formed. This mixture is transferred
into a feed
tank, and using a gear pump, it is pumped into micropastillisation equipment,
for example
as supplied by Sandvik Process Systems, Totowa New York, using a perforated
drum
with perforations of lmm diameter, spaced 2.Smm apart. The apparatus deposits
pastilles
onto a smooth surfaced drum coated with a film of silicone oil and heated to
~30°C.
When one quarter of the drum is covered by pastilles, the drum is stopped from
rotating.
The pastilles are dried using a hot air heater until the surfaces of the
pastilles are dry to
the touch. The resulting particles are then scraped off and collected.
Example 2
A process of making foamed components of the invention in the form of tablets
beads or
particles
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Apparatus: Microbalance, graduated 100m1 flask, Kenwood "Chef ' food processor
with
provided whisk and mixing bowl, glass or plastic moulds, spatula.
Chemicals: Poly (vinyl alcohol) (Aldrich chemicals, molecular weight Mw= 30-
70k),
Glycerol (99 %, Aldrich chemicals), Citric Acid (Aldrich, Citric Acid, USP
Anhydrous),
distilled water, dry ice (or solid phase COZ), thermally insulated box.
Procedure
1. Weigh 50 ~0.2 grams of PVA, 30 ~0.2 grams of glycerol, 50 ~0.2 grams of
cyclohexane dimethanol.
2. Mix the PVA, glycerol and Citric acid using the mixer set a low speed (mark
2; low
sheer).
3. Add 50 ~ lml of water gradually to the dry mix maintaining the mechanical
mix for 2
minutes. A smooth gel should be obtained.
4. Increase the mix speed high sheer to the maximum setting (mark 8). Add 10-
20 ml of
water until a PVA foam is forming. Maintain high shear mixing for 3 minutes.
5. The active ingredients, for example from 2-10 gram of enzyme, are
progressively
added to the foam under a maintained mechanical mixing so that a uniform
active
foam is obtained.
6. Stop mixing. Spread the PVA foam in moulds avoiding any collapsing of the
structure.
7. Place the filled moulds in a thermally insulated box 1/3 filled with dry
ice. Leave to
freeze for 5 hours.
8. Quickly place frozen samples in a vacuum freeze-dryer (Edward XX) for 24
hours.
9. Remove dried sample from moulds.
Any active ingredient can be added in step 5, at any level, normally up to
about 50 grams,
for example fabric softeners, bleaching species, nonionic surfactants.
Any dissolution aid can be added in step 5, at any level, normally up to about
50 grams,
for example cyclohexane dimethanol, or sodium toluene sulfonate.
Example 3
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A process of making foam components of the invention, in the form of tablets,
beads or
particles
Apparatus: as described in the above example
Chemicals: Poly (vinyl alcohol) (Aldrich chemicals, molecular weight Mw= 30-
70k),
Glycerol (99 %, Aldrich chemicals), Sodium carbonate (Aldrich, Anhydrous),
Dodecyl
Sulphate surfactant (Aldrich), distilled water, Petri dish (diameter 90 mm),
Oven (set at
45 °C ~2°C)
Process:
1. Weigh 50 ~0.2 grams of PVA, 30 ~0.2 grams of glycerol, 20 ~0.2 grams of
cyclohexane dimethanol, 20 ~0.2 grams of sodium carbonate, and 2 ~0.2 grams of
dodecyl sulphate.
2. Mix the PVA, glycerol, citric acid and dodecyl sulphate using the mixer set
a low
speed (mark 2).
3. Add 50 ~ lml of water gradually to the dry mix maintaining the mechanical
mix for 2
minutes. A smooth gel should be obtained.
4. Add the active ingredient, for example 5 gram enzyme, and sodium carbonate
and mix
vigorously for 30 second until a fully expanded foam is obtained
5. Spread the foam in petri dish in a uniform 1 cm thick layer
6. Place petri dish in 40 °C oven for 24 hours.
7. Remove the dried foam film from mould.
Any active ingredient can be added in step 4, at any level, normally up to
about 50 grams,
for example fabric softeners, bleaching species, nonionic surfactants.
Any dissolution aid can be added in step 1 at any level, normally up to about
50 grams,
for example SDS, STS, SXS, SCS, CHDM.
This was repeated by using SSwt% polycarboxylic acid polymer, 20wt% anhydrous
sodium carbonate and 25wt% enzyme, softening clay etc.; and repeated by using
45wt%
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polycarboxylic acid polymer, l5wt% polyethylene glycol, 20wt% anhydrous sodium
carbonate and 20wt% enzyme, softening clay etc.
