U.S. patent application number 10/477538 was filed with the patent office on 2004-07-08 for injection moulded containers.
Invention is credited to Fregonese, Daniele, Guzmann, Marcus, Wiedemann, Ralf.
Application Number | 20040129597 10/477538 |
Document ID | / |
Family ID | 9914804 |
Filed Date | 2004-07-08 |
United States Patent
Application |
20040129597 |
Kind Code |
A1 |
Fregonese, Daniele ; et
al. |
July 8, 2004 |
Injection moulded containers
Abstract
The present invention provides a rigid, water-soluble container
made of an injection moulded poly(vinyl alcohol) and/or a cellulose
ether, which container encases a fabric care, surface care or
dishwashing composition.
Inventors: |
Fregonese, Daniele; (Venice,
IT) ; Guzmann, Marcus; (Leimen, DE) ;
Wiedemann, Ralf; (Griesheim, DE) |
Correspondence
Address: |
Norris McLaughlin & Marcus
30th Floor
220 East 42nd Street
New York
NY
10017
US
|
Family ID: |
9914804 |
Appl. No.: |
10/477538 |
Filed: |
November 12, 2003 |
PCT Filed: |
May 16, 2002 |
PCT NO: |
PCT/GB02/02230 |
Current U.S.
Class: |
206/524.7 |
Current CPC
Class: |
B29L 2031/712 20130101;
B65D 81/3876 20130101; C11D 17/042 20130101; B29K 2995/0059
20130101; B29C 45/16 20130101; B29C 45/0001 20130101 |
Class at
Publication: |
206/524.7 |
International
Class: |
B65D 085/84 |
Foreign Application Data
Date |
Code |
Application Number |
May 17, 2001 |
GB |
0112048.4 |
Claims
1. A rigid, water-soluble container made entirely or in part of an
injection moulded water-soluble polymer, which polymer when
dissolved in water is active in detergency, in which container is
present a fabric care, surface care or dishwashing composition,
provided that the polymer is not poly (vinyl alcohol).
2. A rigid, water-soluble container as claimed in claim 1 made
entirely or in part of an injection moulded water-soluble polymer
which polymer when dissolved in water is active as a water softener
or as a dye transfer inhibitor.
3. A rigid, water-soluble container, as claimed in claim 2, made
entirely or in part of an injection moulded water-soluble polymer
which polymer is poly(vinylpyrrolidone), poly(acrylic acid) or an
ester thereof or poly(maleic acid) or an ester thereof, or a
copolymer of any thereof.
4. A rigid, water-soluble container made of at least two
water-soluble injection moulded polymers, a first polymer selected
from poly(vinyl alcohol), a cellulose derivative, and
poly(glycolide), poly(glycolic acid), poly(lactide), poly(lactic
acid) or a copolymer of any thereof; and a second water-soluble
polymer which polymer when dissolved in water is active in
detergency.
5. A rigid, water-soluble container according to claim 4 wherein
the first and additional polymer(s) are simultaneously or
sequentially injection moulded.
6. A rigid, water-soluble container according to any one of the
preceding claims which has two or more compartments.
7. A rigid, water-soluble container according to any one of the
preceding claims which comprises a polymer selected from at least
one of the following; poly(vinylpyrrolidone), poly(acrylic acid) or
an ester thereof or poly(maleic acid) or an ester thereof,or a
copolymer of any thereof.
8. A rigid, water-soluble container according to any one of the
preceding claims wherein the container is made from a water-soluble
receptacle part and is sealed by a water-soluble closure part,
preferably in the form of a film or injection-moulded, rigid
closure.
9. A rigid, water-soluble container according to claim 8 wherein
the closure part comprises a poly(vinyl alcohol) film or
closure.
10. A rigid, water-soluble container according to claim 8 or claim
9, wherein the receptacle part has side walls which terminate at
their upper end in an outward flange, to which the closure part is
sealingly secured.
11. A rigid, water-soluble container according to claim 8 wherein
the closure part is a plastics film.
12. A rigid, water-soluble container according to any one of the
preceding claims wherein the composition comprises a powder, gel,
paste or low water liquid formulation.
13. A rigid, water-soluble container according to any one of claims
10 to 12 wherein the container comprises a tablet formulated for
delayed and/or sustained release of a material.
14. A rigid, water-soluble container according to claim 8 wherein
the receptacle part defines two or more compartments and at least
one compartment is made entirely or in part of a water-soluble
polymer which when dissolved in water is active in detergency.
15. A rigid, water-soluble container according to claim 14 wherein
the receptacle part comprises an upstanding wall which separates
compartments thereof.
16. A rigid, water-soluble container according to claim 14 wherein
the polymer active in detergency is selected from selected from at
least one of the following; poly(vinylpyrrolidone), poly(acrylic
acid) or an ester thereof or poly(maleic acid) or an ester
thereof,or a copolymer of any thereof.
17. A rigid, water-soluble container according to claim 6 wherein a
first compartment is made entirely or in part of a polymer which
when dissolved in water is active in detergency.
18. A rigid, water-soluble container according to claim 14 wherein
at least one compartment is made at least partly of a second
polymer which is poly(vinyl alcohol), a cellulose derivative,
preferably an ether or hydroxypropyl methyl cellulose,
poly(glycolide), poly(glycolic acid), poly(lactide), poly(lactic
acid) or a copolymer of any thereof.
19. A rigid, water-soluble container according to claim 18 wherein
the second polymer is poly(vinyl alcohol).
20. A rigid, water-soluble container according to claim 18 or.19
wherein a first compartment dissolves in water at a different rate
than a second compartment.
21. A rigid, water-soluble container according to any one of claims
8 to 11 wherein the receptacle part comprises an outwardly facing
opening into which a tablet is press-fitted.
22. A rigid, water-soluble container according to any one of claims
8 to 30 wherein the closure part is a transparent or translucent
material.
23. A rigid, water-soluble container according to any one of claims
1 to 22 made entirely or in part of polyvinylpyrolidine.
24. An array of rigid, water-soluble washing containers as defined
in any one of claims 1 to 23 which are joined together but are
readily separable from each other for use.
25. An array according to claim 24 wherein the array has a line of
symmetry extending between capsules, and the two halves of the
array are folded together about the line of symmetry, with the
closure parts in face-to-face contact.
26. A process for the manufacture of an array as defined in claim
24 or 25, which method comprises: forming an array of receptacle
parts, each receptacle part being connected to adjacent receptacle
parts, but being separable from them by a snap or tear action;
charging the receptacle parts with washing composition; and
sealingly securing a sheet of a water-soluble polymer over the top
of the array, to form the closure parts for all the receptacle
parts of the array.
27. A process for the manufacture of a container as claimed in any
claim from 1 to 23, which comprises melting the polymer(s),
injecting the molten polymer(s) into a mould, removing the rigid
water soluble container from the mould and adding the fabric care,
surface care, or dishwashing composition into the container.
28. A process according to claim 27 wherein a first polymer and an
additional polymer(s) are simultaneously or sequentially injected
into the mould.
29. A process according to claim 28 wherein the first polymer and
the additional polymer(s) are sequentially injected into the mould,
in any order, by one of the following techniques, multi-component
injection moulding or sandwich injection moulding.
30. A process according to claim 29 wherein the first polymer and
the additional polymer(s) are sequentially injected into the mould,
in any order, injection moulding a polymer or molten polymer mix
into a mould, removing the solid polymer and inserting into a
second mould and injection moulding a second polymer or polymer mix
into the second mould.
31. A process according to claim 29 wherein the first polymer and
the additional polymer(s) are sequentially injected into the mould,
in any order, injection moulding a polymer or molten polymer mix
into a part of a mould, injection moulding a second polymer or
molten polymer mix into a further part of the mould.
32. A process according to claim 29 wherein the first polymer and
the additional polymer(s) are simultaneously injection moulded into
the mould as a molten mix.
33. A process according to any one of claims 27 to 32 comprising
the additional step of sealing the container.
34. A rigid, water-soluble container made entirely or in part of an
injection moulded water-soluble polymer, in which container is
present a fabric care, surface care or dishwashing composition and
has bound to the inside or outside of the container or encased
within the container a second water-soluble polymer which polymer
when dissolved in water is active in detergency.
35. A rigid, water-soluble container as claimed in claim 34 wherein
the second polymer is polyvinylpyrolidine, polyacrylic acid or an
ester thereof, polymaleic acid or an ester thereof, or a copolymer
of any thereof.
36. A rigid, water-soluble container as claimed in claim 34 or 35
wherein the second polymer is in the form of a shaped article.
37. A rigid, water-soluble container as claimed in any claim from
34 to 36 wherein the container is made entirely or in part of poly
(vinyl alcohol).
Description
[0001] The present invention relates to rigid, water-soluble
containers, in particular to such containers that may be utilised
for the delivery into an aqueous environment of a fabric care,
surface care or dishwashing composition.
[0002] Clothes washing compositions may be delivered to a clothes
washing machine by a delivery tray from which the composition is
fed into the washing drum, or they may be placed directly into the
washing drum. The washing compositions may be in powder, liquid or
block form. Liquid compositions have the disadvantage that they may
be spilt. The same applies to powder compositions. Powder
compositions have the additional disadvantage that they may produce
dust which can be inhaled. These problems are overcome or lessened
when blocks of washing composition are used. These are normally
individually wrapped. On unwrapping a block, for use, it is still
possible that some dust may be produced. Additionally it is an
inconvenience for the consumer to have to unwrap the block.
Furthermore it is almost impossible for the user to avoid some
contact between the block and his or her skin, so leading to a
requirement for the user to wash their hands after starting the
washing machine. In fact, all of the methods described involve a
risk of contact between the composition and the skin, and it is
desirable in all cases for the user to wash their hands after
starting the washing machine. In this context it should be borne in
mind that many compositions contain enzymes to assist the cleaning
action. Even though the user may tolerate enzyme residues which may
be left in clothes after washing, they may still not tolerate
contact between the concentrated washing composition containing the
enzymes, and the skin.
[0003] Similar considerations apply in relation to other areas
including fabric care, surface care and dishwashing. Thus, in
relation in particular to dishwashing compositions, there are also
problems of spillage, dust generation, skin contact and
inconvenience.
[0004] It is known to package chemical compositions which may be of
a hazardous or irritant nature in water-soluble or
water-dispersible materials such as films. The package can simply
be added to water in order to dissolve or disperse the contents of
the package into the water.
[0005] For example, WO 89/12587 discloses a package which comprises
an envelope of a water-soluble or water-dispersible material which
comprises a flexible wall and a water-soluble or water-dispersible
heat seal. The package may contain an organic liquid comprising,
for example, a pesticide, fungicide, insecticide or herbicide.
[0006] CA-A-1,112,534 discloses a packet made of a water-soluble
material in film form enclosing within it a paste-form, automatic
dishwasher-compatible detergent composition. The water-soluble
material may be, for example, poly(vinyl alcohol), polyethylene
oxide or methyl cellulose.
[0007] It is also known to form water-soluble containers by
thermoforming a water-soluble material. For example, WO 92/17382
discloses a package containing an agrochemical such as a pesticide
comprising a first sheet of non-planar water-soluble or
water-dispersible material and a second sheet of water-soluble or
water-dispersible material superposed on the first sheet and sealed
to it by a continuous closed water-soluble or water-dispersible
seal along a continuous region of the superposed sheets.
[0008] The above methods of packaging have, however, a number of
disadvantages.
[0009] The first disadvantage is that they do not have a
particularly attractive appearance. In fields such as containers
used in the domestic environment, an attractive appearance for an
article is extremely desirable. Liquids contained in envelopes of
water-soluble film can have a limp, unattractive appearance.
[0010] The second disadvantage is that it is difficult to form two
or more separate compartments in the packaging so that two
incompatible components are both enclosed but separated from each
other. Although an arrangement has been described to separate
incompatible materials in flexible pouches in WO 93/08095, the
method proposed is complex and is not currently achievable in
large-scale manufacturing. It cannot, therefore, be used for
producing large numbers of containers.
[0011] The third disadvantage is that there is only limited control
of the release profile of the compositions held in the containers.
For example, when a composition is held between two planar
water-soluble films or in a thermoformed package, the composition
is simply released at the time when the films dissolve or disperse
in water. While it may be possible to control to a certain extent
the timing of the start of release of the contents, there can be no
control over the rate of release of the contents since the entire
film dissolves or disperses at about the same time. Furthermore it
can be difficult to provide an extended time before the contents of
the package are released. An additional problem also arises with
thermoformed packages. If the thermoforming is not carefully
controlled there may be inadvertent thinning of the film material
at the points where the material is drawn down into the mould when
it is thermoformed. This could release the contents of the package
early. Additionally, in all of the above packages, it is not
possible to release different compositions at different times or at
different rates since, as discussed above, it is not possible to
incorporate more than one composition in each water-soluble
container.
[0012] The fourth disadvantage is that the containers cannot be
produced at a particularly fast rate. When the containers are
produced by heat-sealing planar films or by thermoforming, the
containers have to be immediately filled and sealed. All of these
procedures have to be carried out in succession. This means that it
is not possible to obtain a quick throughput for mass-market goods
such as household products. For example, standard thermoforming
machines can only produce around 400 to 800 containers per
minute.
[0013] The present invention seeks to provide water-soluble
containers which overcome some or all of the above
disadvantages.
[0014] The present invention has a number of different aspects and
embodiments as follows:
[0015] A rigid, water-soluble container made entirely or in part of
an injection moulded water-soluble polymer, which polymer when
dissolved in water is active in detergency, in which container is
present a fabric care, surface care or dishwashing composition,
provided that the polymer is not poly (vinyl alcohol).
[0016] By the use of the term "active in detergency" we mean that
the polymer can aid the efficiency of the fabric care, surface care
or dishwashing composition. Preferably it is excluded from the
scope of polymers which are active in detergency poly(vinyl
alcohol). Preferably a polymer which is active in detergency is a
water softening polymer or a dye transfer inhibitor polymer.
Specific polymers which are preferred are polyvinylpyrrolidine,
polyacrylic acid or an ester thereof, polymaleic acid or an ester
thereof, or a copolymer of any thereof. Also included are
interpolymers which comprise a blend of any of the above or in
addition any other polymer that is also water-soluble. To be active
in detergency the polymer must be present in the wash in sufficient
quantities to produce the required effect. For example, in an
injection moulded container containing a fabric cleaning
composition should contain at least 0.2 grams of PVP, ideally at
least 0.4 grams. The use of poly(acrylic acid) or poly(maleic acid)
or an ester of either thereof of a copolymer of any thereof in an
injection moulded container containing a fabric cleaning
composition should contain at least 2 grams of the polymer to
provide adequate water softening. It will be appreciated that not
all of the amount of the polymer need be present in the container,
a percentage of the polymer may be present inside the container,
preferably less than 70% wt, ideally less than 50% wt. For other
polymers which are active in detergency it is a simple process to
determine the amount of polymer needed.
[0017] It will be appreciated that the container may be made in
part by any other water-soluble polymer. Therefore, a further
feature of the invention is a rigid, water-soluble container made
of at least two injection moulded polymers, a "first" water-soluble
polymer, preferably selected from poly(vinyl alcohol); a cellulose
derivative (such as an ether or hydroxypropyl methyl cellulose);
and poly(glycolide), poly(glycolic acid), poly(lactides), poly
(lactic acid) or a copolymer thereof; and a "second" water-soluble
polymer which polymer when dissolved in water is active in
detergency.
[0018] The present invention further provides a method of ware
washing, comprising use of a container, as defined above, the
method comprising introducing the container into a ware washing
machine prior to commencement of the washing process, the container
being entirely consumed during the washing process. The ware
washing machine may, for example, be a dishwashing or laundry
washing machine.
[0019] The containers of the present invention overcome some or all
of the above disadvantages.
[0020] Firstly, because the containers are rigid and
self-supporting, they have an attractive, uniform appearance which
does not vary between different containers. In addition, a wide
variety of different shapes and designs are available. Furthermore,
the rigid containers can easily have various elements incorporated
which are considered to be pleasing to the eye but which are
impossible to incorporate in the flexible containers discussed
above.
[0021] Secondly, because the containers are rigid, it is easily
possible to introduce two or more compartments, or have larger
compartments separated by walls, to separate mutually incompatible
ingredients. The containers can also hold part of the composition
on an external surface, for example in an indentation. Furthermore,
the container can be moulded is almost any shape that might be
useful. In particular it can be given raised or lowered areas.
[0022] Thirdly, it is possible to control the release profile of
the contents of the container. Since the container is rigid, it is
possible to adapt the width of all of the walls of the container to
control both the start of release of the composition as well as the
rate of release. For example, one or more walls may be made thin in
order to have an early release of the composition. Alternatively
all the walls may be thick in order to ensure that there is a
delayed release of the composition. The rate of release of the
composition may also be controlled by ensuring that only part of
the container has thin walls which are dissolved or dispersed
before the remainder of the container. Different walls or parts of
walls of the container may be prepared from different water-soluble
polymers which have different dissolution characteristics. For
example, a first compartment may be fully enclosed by a polymer
which dissolves at a higher or lower temperature than the polymer
enclosing a second compartment. Thus different components can be
released at different times. If the container holds a solid or
gelled composition, it is not even necessary for the container to
fully enclose the composition. A part may be left exposed, so that
it immediately begins to dissolve when added to water.
[0023] Fourthly, since the containers are rigid and
self-supporting, they can easily be filled on a production line
using normal filling equipment. Such filling equipment is quite
capable of filling at least 1500 containers per minute.
[0024] Fifthly the containers as described provide added efficiency
to the compositions contained therein by themselves being active in
detergency.
[0025] Desirably the container, apart from its contents, consists
essentially of the injection-moulded polymer or polymers.
[0026] It is possible for suitable additives such as plasticizers
and lubricants to be included. Plasticizers are generally used in
an amount of up to 20 wt %, for example from 15 to 20 wt %,
lubricants are generally used in an amount of 0.5 to 5% wt % and
the polymer is generally therefore used in an amount of 75 to 84.5
wt %, based on the total amount of the moulding composition.
[0027] The container is generally cold water (20.degree. C.)
soluble, but may be insoluble in cold water at 20.degree. C. and
only become soluble in warm water or hot water having a temperature
of, for example, 30.degree. C., 40.degree. C., 50.degree. C. or
even 60.degree. C.
[0028] For certain applications or uses, containers soluble in
aqueous environments at temperatures as low as 5.degree. C. are
also desirable.
[0029] In order to ensure that the polymer is capable of being
injection moulded, it is usual to incorporate components such as
plasticizers and mould release agents in an amount of up to, for
example, 15 wt % of the composition. Suitable plasticizers are, for
example, pentaerthyritol such as depentaerythritol, sorbitol,
mannitol, glycerine and glycols such as glycerol, ethylene glycol
and polyethylene glycol. Solids such as talc, stearic acid,
magnesium stearate, silicon dioxide, zinc stearate, and colloidal
silica may also be used.
[0030] Poly(vinylpyrollidone) may be moulded at temperatures of
from 120-180.degree. C., depending upon the formulation selected
and the melt flow index required.
[0031] Poly(acrylic acid) may be moulded at temperatures of from
180-220.degree. C., for example, depending upon the formulation
selected and the melt flow index required.
[0032] Poly(maleic acid) may be moulded at temperatures of, from
180-220.degree. C. for example, depending upon the formulation
selected and the melt flow index required.
[0033] The PVOH, when used as a second polymer in the container,
may be moulded at temperatures of, for example, from
180-220.degree. C., depending upon the formulation selected and the
melt flow index required. A preferred PVOH which is already in a
form suitable for injection moulding is sold in the form of
granules under the name CP1210T05 by Soltec Development SA of
Paris, France. The PVOH preferably used to form the container of
the present invention may be partially or fully alcoholised or
hydrolysed. For example it may be from 40-100%, preferably 70-92%,
more preferably about 88%, alcoholised or hydrolysed
polyvinylacetate.
[0034] Preferably the container is a container enclosing a washing
composition.
[0035] All of the polymer compositions may also include other
components such as colouring agents and components which modify
their properties.
[0036] Injection moulding techniques are well known to the skilled
person and are well described in the literature (see, for example a
good summary is provided in "The Wiley Encyclopedia of Packaging
Technology" Wiley Interscience 1986). Special techniques, described
below, are preferred features of the invention for producing
containers having more than one type of polymer.
[0037] Simultaneous Injection Moulding
[0038] 1) two or more polymers are molten mixed and injected into a
mould;
[0039] 2) two or more polymers are injected into a mould through
more than one gate, each gate allowing simultaneous injection of a
single polymer or molten mix into the mould;
[0040] 3) simultaneously injection moulding two or more
compartments and then joining the compartments together.
[0041] Sequential Injection Moulding
[0042] 1) multi-component injection moulding;
[0043] 2) sandwich injection moulding;
[0044] 3) sequentially injection moulding two or more;
[0045] 4) compartments and then joining the compartments
together.
[0046] Multi-component injection moulding covers two distinct
processes
[0047] A) injection moulding a polymer or molten polymer mix into a
mould, removing the solid polymer and inserting it into a second
mould and injection moulding a second polymer or polymer mix into
the second mould;
[0048] B) injection moulding a polymer or molten polymer mix into a
part of a mould, injection moulding a second polymer or molten
polymer mix into a further part of the mould.
[0049] Steps A) and B) may be repeated more than once and may be
combined. It will be appreciated by the skilled person that the
first injection moulded polymer must survive the pressure and
temperature conditions of the second, or subsequent, injection
moulding.
[0050] For step B) the first polymer or molten mix may be prevented
from entering parts of the mould by any physical means, such as,
gates, gravity, positive or negative pressure.
[0051] Sandwich injection moulding (or sometimes called skin-core
injection moulding) comprises injection moulding a polymer or
molten polymer mix into a mould until it is partially filled and
then injecting a second polymer or molten polymer mix into the same
mould through the same gate to form the core. An additional step of
sealing the core may be performed.
[0052] It will be appreciated that any combination of simultaneous
and sequential injection moulding may be used.
[0053] A further technique that can be used is to coat part or the
entire container, the container being moulded from any
water-soluble polymer, with a polymer which is active in
detergency, provided that the polymer is not poly (vinyl alcohol).
Coating may be achieved by dipping the container into a solution of
polymer or in molten polymer or by spray coating of a solution of
polymer or molten polymer. It will be appreciated that polymers
that are active in detergency but which cannot be injection moulded
can be used, preferably, PVNO.
[0054] In all aspects and embodiments of the present invention, the
container generally comprises a water-soluble receptacle part which
holds the composition and a water-soluble closure part, which may
simply close the receptacle part or may itself have at least some
receptacle function. The receptacle part preferably has side walls
which terminate at their upper end in an outward flange in which
the closure part is sealingly secured, especially if the closure
part is in the form of a film. Ideally the closure part is joined
to the receptacle part directly by means of a hinge part,
preferably the receptacle, closure and hinge part are caste in a
single mould. The securement may be by means of an adhesive but is
preferably achieved by means of a seal, between the flange and the
closure part. Preferably the receptacle part is connected to the
closure part via a hinge part thus forming a single article which
is easily sealed. Heat sealing may be used or other methods such as
infra-red, radio frequency, ultrasonic, laser, solvent, vibration
or spin welding. An adhesive such as an aqueous solution of PVOH or
a cellulose ether may also be used. The seal is desirably also
water-soluble.
[0055] The closure part may itself be injection moulded or blow
moulded. Preferably, however, it is a plastics film secured over
the receptacle part. The film may, for example, comprise PVOH or a
cellulose ether such as HPMC or another water-soluble polymer.
[0056] The receptacle part may define two or more compartments and
at least one compartment is made entirely or in part of a
water-soluble polymer which when dissolved in water is active in
detergency.
[0057] The container walls have thicknesses such that the
containers are rigid. For example, the outside walls and any inside
walls which have been injection moulded independently have a
thickness of greater than 100 .mu.m, for example greater than 150
.mu.m or greater than 200 .mu.m, 300 .mu.m, or 500 .mu.m, 750 .mu.m
or 1 mm. Preferably, the closure part is of a thinner material than
the receptacle part. If different compartments having different
dissolution times are required, different wall thicknesses can be
used. A thickness difference of from 100 .mu.m to 500 .mu.m,
preferably from 250 .mu.m to 350 m, would give a suitable
difference in release times.
[0058] Preferably, the closure part dissolves in water (at least to
the extent of allowing the washing composition in the receptacle
part to be dissolved by the water; and preferably completely) at
40.degree. C. in less than 5 minutes, preferably in less than 2
minutes.
[0059] The receptacle part and the closure part could be of the
same thickness or different thicknesses. The closure part may, for
example, be of higher solubility than the receptacle part, in order
to dissolve more quickly.
[0060] In an alternative feature of the invention we describe a
rigid, water-soluble container made entirely or in part of an
injection moulded water-soluble polymer, in which container is
present a fabric care, surface care or dishwashing composition and
has bound to the inside or outside of the container or encased
within the container a second polymer which polymer when dissolved
in water is active in detergency.
[0061] Preferably, the second polymer is polyvinylpyrrolidine,
polyacrylic and or an ester thereof, polymaleic acid or an ester
thereof, or a copolymer of any thereof.
[0062] The second polymer may be in the form of a shaped article,
such as a ball, rod, or as a sheet. When attached to the outside or
inside of the container the second polymer can be added to the
mould prior to injection moulding.
[0063] Preferably, the container is made entirely or in part of
poly (vinyl alcohol) in the above preferred feature
[0064] Preferably, the washing container is generally cuboid in its
external shape, with the top wall being formed by the closure part,
and with the side walls and base wall being formed by the
receptacle part.
[0065] Preferably, a washing container of the invention is
manufactured by forming an array of receptacle parts, each
receptacle part being joined to adjacent receptacle parts, and
being separable from them by a snap or tear action. The array is
preferably one which has columns and rows of the receptacle parts.
The receptacle parts may be separated by frangible webs of the
water-soluble polymer such as PVOH or a cellulose ether.
[0066] Alternatively, the receptacle parts may be manufactured with
the aforementioned flanges, such that they are separated from each
other by a line of weakness. For example the material may be
thinner, and so able to be broken or torn readily. The thinness may
be a result of the moulding process or, preferably, of a later
scoring step.
[0067] In the manufacturing method, the array, formed by injection
moulding, is fed to a filling zone, and all the receptacle parts
are charged with the washing composition. A sheet of a
water-soluble polymer such as PVOH or a cellulose ether may then be
secured over the top of the array, to form the closure parts for
all the receptacle parts of the array. The array may then be split
up into the individual washing capsules, prior to packaging, or it
may be left as an array, for packaging, to be split by the user.
Preferably, it is left as an array, for the user to break or tear
off the individual washing capsules. Preferably, the array has a
line of symmetry extending between capsules, and the two halves of
the array are folded together, about that line of symmetry, so that
closure parts are in face-to-face contact. This helps to protect
the closure parts from any damage, between factory and user. It
will be appreciated that the closure parts are more prone to damage
than the receptacle parts. Alternatively two identical arrays of
washing capsules may be placed together with their closure parts in
face-to-face contact, for packaging.
[0068] In some embodiments of the invention the container, capsule
or receptacle part may define a single compartment. In other
embodiments of the invention the container, capsule or receptacle
part may define two or more compartments, which contain different
products useful in a washing process. In such a situation a
dividing wall or walls of the compartments preferably terminate at
the top of the container, i.e. in the same plane as the top edges
of the side walls, so that when the receptacle part is closed by
the closure part the contents of the compartments cannot mix. The
container may be provided with an upstand, preferably spaced from
the side walls thereof, and preferably of generally cylindrical
shape. If wished, the remaining volume of the container can be
divided into two or more parts by means of walls extending between
the upstand and the side walls.
[0069] The container may be formed with an opening, for example a
depression, formed in the side wall or the base wall, and
preferably being open in the outward direction. That is to say, it
preferably does not form part of the main volume defined by the
container. Preferably the opening is adapted to receive, in a
press-fit manner, a solid block (for example a tablet) of a
composition, for example a material useful in a washing
process.
[0070] Preferably, the closure part is of a transparent or
translucent material, so that the contents of the washing capsule
can be seen.
[0071] Preferably, the container is of a transparent or translucent
material, so that the contents of the washing capsule can be
seen.
[0072] The washing composition within the container, or within a
compartment thereof, need not be uniform. For example during
manufacture it could be fed first with a settable agent, for
example a gel, useful in a washing process, and then with a
different material. The first material could dissolve slowly in the
washing process so as to deliver its charge over a long period
within the washing process. This might be useful, for example, to
provide immediate, delayed or sustained delivery of a softening
agent in a clothes washing container.
[0073] The container may, for example, be in at least two parts (a
body part and a cap part) which fit tightly, and preferably
sealingly and inseparably, together to form a compartment in which
is stored the ingredient to be achieved. In one example, the
container or capsule may have three parts--a body such as a
receptacle, a first cap, and then a second cap to fit over the
closed end of either the body or the first cap, so as to result in
a capsule with two separate compartments. Where there are three
such parts (or more; four parts--a body and three caps--make three
compartments, and so on), then naturally the ingredients in each
compartment may be the same or they may be different.
[0074] In all embodiments of the present invention one compartment
may contain, for example, a liquid or solid component (such as a
powder, granules or a compressed or gelled tablet) and another may
contain a different liquid or solid component (such as a powder,
granules or a compressed or gelled tablet). Alternatively, more
than one component may be present in one or more compartments. For
example a compartment may contain a solid component, for example in
the form of a ball or pill (such as a powder, granules or a
compressed or gelled tablet), and a liquid component.
[0075] Desirably the composition has a mass of at least 10 g or 15
g, for example, from 10 g or 15 g to 100 g, especially from 10 g to
15 g to 40 g. For example, a dishwashing composition may weigh from
10 g or 15 g to 20 g, a water-softening composition may weigh from
25 g to 35 g, and a laundry composition may weigh from 10 g to 40
g, 20 g to 40 g or 30 g to 40 g.
[0076] In general the maximum dimension of the container is 5 cm.
For example, a cuboid container may have a length of 1 to 5 cm,
especially 3.5 to 4.5 cm, a width of 1.5 to 3.5 cm, especially 2 to
3 cm, and a height of 1 to 2 cm, especially 1.25 to 1.75 cm.
[0077] The composition may comprise a powder, gel, paste or low
water liquid foundation.
[0078] The composition contained by the container may be, for
example, any which is suitable for the designated application, for
example a clothes washing or dishwashing application. It may be a
powder or a liquid but if a liquid, may be a low water formulation,
preferably having a maximum water content of 5 wt %, in order to
maintain the integrity of the walls of the capsule or a higher
water formulation containing, for example, at least 8 wt % water.
It will be appreciated that higher water contents may be present
where the water is chemically or physically bound. The composition
may be formulated having regard to the fact that the user will not
come into contact with the composition, whether by inhalation or by
skin contact. For example, the composition may include an enzyme,
without concern about physical contact between the composition
containing the enzyme, and the user.
[0079] If the container contains an aqueous liquid having a
relatively high free water content, it may be necessary to take
steps to ensure the liquid does not attack the water-soluble
polymer if it is soluble in cold water (20.degree. C.), or water at
a temperature of up to, say, 35.degree. C. Steps may be taken to
treat the inside surfaces of the container, for example by coating
it with agents such as PVdC (poly(vinylidene chloride))or PTFE
(polytetrafluoroethylene), or to adapt the composition to ensure
that it does not dissolve the polymer. For example, it has been
found that ensuring the composition has a high ionic strength or
contains an agent which minimises water loss through the walls of
the container will prevent the composition from dissolving the
polymer from the inside. This is described in more detail in
EP-A-518,689 and WO 97/27743.
[0080] The composition held within the container depends, of
course, on the intended use of the composition. It may, for
example, contain surface active agents such as an anionic,
non-ionic, cationic, amphoteric or zwitterionic surface active
agent or mixture thereof.
[0081] Examples of anionic surfactants are straight-chained or
branched alkyl sulfates and alkyl polyalkoxylated sulfates, also
known as alkyl ether sulfates. Such surfactants may be produced by
the sulfation of higher C.sub.8-C.sub.20 fatty alcohols.
[0082] Examples of primary alkyl sulfate surfactants are those of
formula:
ROSO.sub.3.sup.-M.sup.+
[0083] wherein R is a linear C.sub.8-C.sub.20 hydrocarbyl group and
M is a water-solubilising cation. Preferably R is C.sub.10-C.sub.16
alkyl, for example C.sub.12-C.sub.14, and M is alkali metal such as
lithium, sodium or potassium.
[0084] Examples of secondary alkyl sulfate surfactants are those
which have the sulfate moiety on a "backbone" of the molecule, for
example those of formula:
CH.sub.3(CH.sub.2).sub.n(CHOSO.sub.3.sup.-M.sup.+)(CH.sub.2).sub.mCH.sub.3
[0085] wherein m and n are independently 2 or more, the sum of m+n
typically being 6 to 20, for example 9 to 15, and M is a
water-solubilising cation such as lithium, sodium or potassium.
[0086] Especially preferred secondary alkyl sulfates are the (2,3)
alkyl sulfate surfactants of formulae:
CH.sub.3(CH.sub.2).sub.x(CHOSO.sub.3.sup.-M.sup.+)CH.sub.3 and
CH.sub.3(CH.sub.2).sub.x(CHOSO.sub.3.sup.-M.sup.+)CH.sub.2CH.sub.3
[0087] for the 2-sulfate and 3-sulfate, respectively. In these
formulae x is at least 4, for example 6 to 20, preferably 10 to 16.
M is cation, such as an alkali metal, for example lithium, sodium
or potassium.
[0088] Examples of alkoxylated alkyl sulfates are ethoxylated alkyl
sulfates of the formula:
RO(C.sub.2H.sub.4O).sub.nSO.sub.3.sup.-M.sup.+
[0089] wherein R is a C.sub.8-C.sub.20 alkyl group, preferably
C.sub.10-C.sub.18 such as a C.sub.12-C.sub.16, n is at least 1, for
example from 1 to 20, preferably 1 to 15, especially 1 to 6, and M
is a salt-forming cation such as lithium, sodium, potassium,
ammonium, alkylammonium or alkanolammonium. These compounds can
provide especially desirable fabric cleaning performance benefits
when used in combination with alkyl sulfates.
[0090] The alkyl sulfates and alkyl ether sulfates will generally
be used in the form of mixtures comprising varying alkyl chain
lengths and, if present, varying degrees of alkoxylation.
[0091] Other anionic surfactants which may be employed are salts of
fatty acids, for example C.sub.8-C.sub.18 fatty acids, especially
the sodium or potassium salts, and alkyl, for example
C.sub.8-C.sub.18, benzene sulfonates.
[0092] Examples of nonionic surfactants are fatty acid alkoxylates,
such as fatty acid ethoxylates, especially those of formula:
R(C.sub.2H.sub.4O).sub.nOH
[0093] wherein R is a straight or branched C.sub.8-C.sub.16 alkyl
group, preferably a C.sub.9-C.sub.15, for example
C.sub.10-C.sub.14, alkyl group and n is at least 1, for example
from 1 to 16, preferably 2 to 12, more preferably 3 to 10.
[0094] The alkoxylated fatty alcohol nonionic surfactant will
frequently have a hydrophilic-lipophilic balance (HLB) which ranges
from 3 to 17, more preferably from 6 to 15, most preferably from 10
to 15.
[0095] Examples of fatty alcohol ethoxylates are those made from
alcohols of 12 to 15 carbon atoms and which contain about 7 moles
of ethylene oxide. Such materials are commercially marketed under
the trademarks Neodol 25-7 and Neodol 23-6.5 by Shell Chemical
Company. Other useful Neodols include Neodol 1-5, an ethoxylated
fatty alcohol averaging 11 carbon atoms in its alkyl chain with
about 5 moles of ethylene oxide; Neodol 23-9, an ethoxylated
primary C.sub.12-C.sub.13 alcohol having about 9 moles of ethylene
oxide; and Neodol 91-10, an ethoxylated C.sub.9-C.sub.11, primary
alcohol having about 10 moles of ethylene oxide.
[0096] Alcohol ethoxylates of this type have also been marketed by
Shell Chemical Company under the Dobanol trademark. Dobanol 91-5 is
an ethoxylated C.sub.9-C.sub.11, fatty alcohol with an average of 5
moles ethylene oxide and Dobanol 25-7 is an ethoxylated
C.sub.12-C.sub.15 fatty alcohol with an average of 7 moles of
ethylene oxide per mole of fatty alcohol.
[0097] Other examples of suitable ethoxylated alcohol nonionic
surfactants include Tergitol 15-S-7 and Tergitol 15-S-9, both of
which are linear secondary alcohol ethoxylates available from Union
Carbide Corporation. Tergitol 15-S-7 is a mixed ethoxylated product
of a C.sub.11-C.sub.15 linear secondary alkanol with 7 moles of
ethylene oxide and Tergitol 15-S-9 is the same but with 9 moles of
ethylene oxide.
[0098] Other suitable alcohol ethoxylated nonionic surfactants are
Neodol 45-11, which is a similar ethylene oxide condensation
products of a fatty alcohol having 14-15 carbon atoms and the
number of ethylene oxide groups per mole being about 11. Such
products are also available from Shell Chemical Company.
[0099] Further nonionic surfactants are, for example,
C.sub.10-C.sub.18 alkyl polyglycosides, such s C.sub.12-C.sub.16
alkyl polyglycosides, especially the polyglucosides. These are
especially useful when high foaming compositions are desired.
Further surfactants are polyhydroxy fatty acid amides, such as
C.sub.10-C.sub.18 N-(3-methoxypropyl) glycamides and ethylene
oxide-propylene oxide block polymers of the Pluronic type.
[0100] Examples of cationic surfactants are those of the quaternary
ammonium type.
[0101] The total content of surfactants in the composition is
desirably 60 to 95 wt %, especially 75 to 90 wt %. Desirably an
anionic surfactant is present in an amount of 50 to 75 wt %, the
nonionic surfactant is present in an amount of 5 to 50 wt %, and/or
the cationic surfactant is present in an amount of from 0 to 20 wt
%. The amounts are based on the total solids content of the
composition, i.e. excluding any solvent which may be present.
[0102] The compositions, particularly when used as laundry washing
or dishwashing compositions, may also independently comprise
enzymes, such as protease, lipase, amylase, cellulase and
peroxidase enzymes. Such enzymes are commercially available and
sold, for example, under the registered trade marks Esperase,
Alcalase and Savinase by Nova Industries A/S and Maxatase by
International Biosynthetics, Inc. Desirably the enzymes are
independently present in the compositions in an amount of from 0.5
to 3 wt %, especially 1 to 2 wt %, when added as commercial
preparations they are not pure and this represents an equivalent
amount of 0.005 to 0.5 wt % of pure enzyme.
[0103] The compositions may, if desired, independently comprise a
thickening agent or gelling agent. Suitable thickeners are
polyacrylate polymers such as those sold under the trade mark
CARBOPOL, or the trade mark ACUSOL by Rohm and Haas Company. Other
suitable thickeners are xanthan gums. The thickener, if present, is
generally present in an amount of from 0.2 to 4 wt %, especially
0.5 to 2 wt %.
[0104] Compositions used in dishwashing independently usually
comprise a detergency builder. The builders counteract the effects
of calcium, or other ion, water hardness. Examples of such
materials are citrate, succinate, malonate, carboxymethyl
succinate, carboxylate, polycarboxylate and polyacetyl carboxylate
salts, for example with alkali metal or alkaline earth metal
cations, or the corresponding free acids. Specific examples are
sodium, potassium and lithium salts of oxydisuccinic acid, mellitic
acid, benzene polycarboxylic acids, C.sub.10-C.sub.22 fatty acids
and citric acid. Other examples are organic phosphonate type
sequestering agents such as those sold by Monsanto under the trade
mark Dequest and alkylhydroxy phosphonates. Citrate salts and
C.sub.12-C.sub.18 fatty acid soaps are preferred. Further builders
are; phosphates such as sodium, potassium or ammonium salts of
mono-, di- or tri-poly or oligo-phosphates; zeolites; silicates,
amorphous or structured, such as sodium, potassium or ammonium
salts.
[0105] Other suitable builders are polymers and copolymers known to
have builder properties. For example, such materials include
appropriate polyacrylic acid, polymaleic acid, and
polyacrylic/polymaleic and copolymers and their salts, such as
those sold by BASF under the trade mark Sokalan.
[0106] The builder is desirably present in an amount of up to 90 wt
%, preferably 15 to 90 wt %, more preferable 15 to 75 wt %,
relative to the total weight of the composition. Further details of
suitable components are given in, for example, EP-A-694,059,
EP-A-518,720 and WO 99/06522.
[0107] The compositions can also optionally comprise one or more
additional ingredients. These include conventional detergent
composition components such as further surfactants, bleaches,
bleach enhancing agents, builders, suds boosters or suds
suppressors, anti-tarnish and anti-corrosion agents, organic
solvents, co-solvents, phase stabilisers, emulsifying agents,
preservatives, soil suspending agents, soil release agents,
germicides, pH adjusting agents or buffers, non-builder alkalinity
sources, chelating agents, clays such as smectite clays, enzyme
stabilizers, anti-limescale agents, colourants, dyes, hydrotropes,
dye transfer inhibiting agents, brighteners, and perfumes. If used,
such optional ingredients will generally constitute no more than 10
wt %, for example from 1 to 6 wt %, the total weight of the
compositions.
[0108] Compositions which comprise an enzyme may optionally contain
materials which maintain the stability of the enzyme. Such enzyme
stabilizers include, for example, polyols such as propylene glycol,
boric acid and borax. Combinations of these enzyme stabilizers may
also be employed. If utilized, the enzyme stabilizers generally
constitute from 0.1 to 1 wt % of the compositions.
[0109] The compositions may optionally comprise materials which
serve as phase stabilizers and/or co-solvents. Examples are
C.sub.1-C.sub.3 alcohols such as methanol, ethanol and propanol.
C.sub.1-C.sub.3 alkanolamines such as mono-, di- and
triethanolamines can also be used, by themselves or in combination
with the alcohols. The phase stabilizers and/or co-solvents can,
for example, constitute 0 to 1 wt %, preferably 0.1 to 0.5 wt %, of
the composition.
[0110] The compositions may optionally comprise components which
adjust or maintain the pH of the compositions at optimum levels.
The pH may be from, for example, 1 to 13, such as 8 to 11 depending
on the nature of the composition. For example a dishwashing
composition desirably has a pH of 8 to 11, a laundry composition
desirable has a pH of 7 to 9, and a water-softening composition
desirably has a pH of 7 to 9. Examples of pH adjusting agents are
NaOH and citric acid.
[0111] The above examples may be used for dish or fabric washing.
In particular dish washing formulations are preferred which are
adapted to be used in automatic dish washing machines. Due to their
specific requirements specialised formulation is required and these
are illustrated below
[0112] Amounts of the ingredients can vary within wide ranges,
however preferred automatic dishwashirig detergent compositions
herein (which typically have a 1% aqueous solution pH of above 8,
more preferably from 9.5 to 12, most preferably from 9.5 to 10.5)
are those wherein there is present: from 5% to 90%, preferably from
5% to 75%, of builder; from 0.1% to 40%, preferably from 0.5% to
30%, of bleaching agent; from 0.1% to 15%, preferably from 0.2% to
10%, of the surfactant system; from 0.0001% to 1%, preferably from
0.001% to 0.05%, of a metal-containing bleach catalyst; and from
0.1% to 40%, preferably from 0.1% to 20% of a water-soluble
silicate. Such fully-formulated embodiments typically further
comprise from 0.1% to 15% of a polymeric dispersant, from 0.01% to
10% of a chelant, and from 0.00001% to 10% of a detersive enzyme,
though further additional or adjunct ingredients may be present.
Detergent compositions herein in granular form typically limit
water content, for example to less than 7% free water, for better
storage stability.
[0113] Non-ionic surfactants useful in ADW (Automatic Dish Washing)
compositions of the present invention desirably include
surfactant(s) at levels of from 2% to 60% of the composition. In
general, bleach-stable surfactants are preferred. Non-ionic
surfactants generally are well known, being described in more
detail in Kirk Othmer's Encyclopedia of Chemical Technology, 3rd
Ed., Vol. 22, pp. 360-379, "Surfactants and Detersive Systems",
incorporated by reference herein.
[0114] Preferably the ADW composition comprises at least one
non-ionic surfactant. One class of non-ionics are ethoxylated
non-ionic surfactants prepared by the reaction of a monohydroxy
alkanol or alkylphenol with 6 to 20 carbon atoms with preferably at
least 12 moles particularly preferred at least 16 moles, and still
more preferred at least 20 moles of ethylene oxide per mole of
alcohol or alkylphenol.
[0115] Particularly preferred non-ionic surfactants are the
non-ionic from a linear chain fatty alcohol with 16-20 carbon atoms
and at least 12 moles particularly preferred at least 16 and still
more preferred at least 20 moles of ethylene oxide per mole of
alcohol.
[0116] According to one preferred embodiment the non-ionic
surfactant additionally comprise propylene oxide units in the
molecule. Preferably this PO units constitute up to 25% by weight,
preferably up to 20% by weight and still more preferably up to 15%
by weight of the overall molecular weight of the non-ionic
surfactant. Particularly preferred surfactants are ethoxylated
mono-hydroxy alkanols or alkylphenols, which additionally comprises
polyoxyethylene-polyoxypropylene block copolymer units. The alcohol
or alkylphenol portion of such surfactants constitutes more than
30%, preferably more than 50%, more preferably more than 70% by
weight of the overall molecular weight of the non-ionic
surfactant.
[0117] Another class of non-ionic surfactants includes reverse
block copolymers of polyoxyethylene and polyoxypropylene and block
copolymers of polyoxyethylene and polyoxypropylene initiated with
trimethylolpropane.
[0118] Another preferred non-ionic surfactant can be described by
the formula:
R.sup.1O[CH.sub.2CH(CH.sub.3)O].sub.x[CH.sub.2CH.sub.2O].sub.y[CH.sub.2CH(-
OH)R.sup.2]
[0119] wherein R.sup.1 represents a linear or branched chain
aliphatic hydrocarbon group with 4-18 carbon atoms or mixtures
thereof, R.sup.2 represents a linear or branched chain aliphatic
hydrocarbon rest with 2-26 carbon atoms or mixtures thereof, x is a
value between 0.5 and 1.5 and y is a value of at least 15.
[0120] Another group of preferred nonionic surfactants are the
end-capped polyoxyalkylated non-ionics of formula:
R.sup.1O[CH.sub.2CH(R.sup.3)O].sub.x[CH.sub.2].sub.kCH(OH)[CH.sub.2].sub.j-
OR.sup.2
[0121] wherein R.sup.1 and R.sup.2 represent linear or branched
chain, saturated or unsaturated, aliphatic or aromatic hydrocarbon
groups with 1-30 carbon atoms, R.sup.3 represents a hydrogen atom
or a methyl, ethyl, n-propyl, iso-propyl, n-butyl, 2-butyl or
2-methyl-2-butyl group x is a value between 1 and 30 and, k and j
are values between 1 and 12, preferably between 1 and 5. When the
value of x is .gtoreq.2 each R.sup.3 in the formula above can be
different. R.sup.1 and R.sup.2 are preferably linear or branched
chain, saturated or unsaturated, aliphatic or aromatic hydrocarbon
groups with 6-22 carbon atoms, where group with 8 to 18 carbon
atoms are particularly preferred. For the group R.sup.3 H, methyl
or ethyl are particularly preferred. Particularly preferred values
for x are comprised between 1 and 20, preferably between 6 and
15.
[0122] As described above, in case x.gtoreq.2, each R.sup.3 in the
formula can be different. For instance, when x=3, the group R.sup.3
could be chosen to build ethylene oxide (R.sup.3.dbd.H) or
propylene oxide (R.sup.3=methyl) units which can be used in every
single order for instance (PO) (EO) (EO), (EO) (PO) (EO), (EO) (EO)
(PO), (EO) (EO) (EO), (PO) (EO) (PO), (PO) (PO) (EO) and (PO) (PO)
(PO). The value 3 for x is only an example and bigger values can be
chosen whereby a higher number of variations of (EO) or (PO) units
would arise.
[0123] Particularly preferred end-capped polyoxyalkylated alcohols
of the above formula are those where k=1 and j=1 originating
molecules of simplified formula:
R.sup.1O[CH.sub.2CH(R.sup.3)O].sub.xCH.sub.2CH(OH)CH.sub.2OR.sup.2
[0124] The use of mixtures of different non-ionic surfactants is
particularly preferred in ADW formulations for example mixtures of
alkoxylated alcohols and hydroxy group containing alkoxylated
alcohols.
[0125] The composition, such as a washing composition within the
container, capsule or receptacle part, or within a compartment
thereof if there is more than one compartment, need not be uniform.
For example during manufacture it could be fed first with a
settable agent, for example a gel, useful in a washing process, and
then with a different material. The first material could dissolve
slowly in the washing process so as to deliver its charge over a
long period within the washing process. This might be useful, for
example, to provide delayed or sustained delivery of a softening
agent in a clothes washing capsule.
[0126] The composition, such as a washing composition may,
especially for dishwashing or laundry, include a tablet. Preferably
a tablet contains a material useful in a washing process and is
formulated to provide slow release of that material during a
washing process and/or delayed release thereof. Delayed release may
be achieved by providing the tablet with a coating which is slow to
dissolve during the washing process. Alternatively the tablet may
provide a quick release of components required early in the wash,
for example water-softening components and/or enzymes. The tablet
may, for example, comprise a disrupting agent, such as one which
effervesces when in contact with water such as a combination of
citric acid and an alkali metal carbonate or bicarbonate.
[0127] A tablet may be provided in the main volume of the
receptacle part or may be provided in an outwardly facing opening
or depression, as previously described.
[0128] When a washing capsule of the invention has a tablet
retained in an outwardly facing opening or depression the tablet is
preferably one which will not transfer any washing composition to
the hands of a user. For example, it may be coated with a soluble
polymeric material. As mentioned above, this may also be desirable
for delayed release of its charge. If it is desired that the tablet
dissolves quickly it may, for example, comprise a disrupting agent
such as an effervescing agent.
* * * * *