U.S. patent application number 10/214854 was filed with the patent office on 2003-03-27 for cleaning and rinsing of textile fabrics.
This patent application is currently assigned to Unilever Home & Personal Care USA, Division of Conopco, Inc.. Invention is credited to Dekker, Francis, Hoekstra, Arjen Jacco, Pacha, Fakhruddin Esmail, Wierenga, Antje Minke.
Application Number | 20030056301 10/214854 |
Document ID | / |
Family ID | 9920295 |
Filed Date | 2003-03-27 |
United States Patent
Application |
20030056301 |
Kind Code |
A1 |
Dekker, Francis ; et
al. |
March 27, 2003 |
Cleaning and rinsing of textile fabrics
Abstract
A method of washing and rinsing a textile fabric using wash and
rinse product comprises: (a) placing in a water permeable
receptacle, a wash composition and a rinse composition; (b)
contacting a washing step comprising contacting the receptacle and
the fabric into contact with a wash liquor; and (c) subsequent to
the washing step (b), a rinse step comprising contacting the
receptacle and the fabric with a rinse liquor. The rinse
composition is formulated such that release of at lest some of the
rinse composition is delayed until the rinse step. Unit dose
products for use in the method are also claimed.
Inventors: |
Dekker, Francis;
(Vlaardingen, NL) ; Hoekstra, Arjen Jacco;
(Vlaardingen, NL) ; Pacha, Fakhruddin Esmail;
(Mumbai, IN) ; Wierenga, Antje Minke;
(Vlaardingen, NL) |
Correspondence
Address: |
UNILEVER
PATENT DEPARTMENT
45 RIVER ROAD
EDGEWATER
NJ
07020
US
|
Assignee: |
Unilever Home & Personal Care
USA, Division of Conopco, Inc.
|
Family ID: |
9920295 |
Appl. No.: |
10/214854 |
Filed: |
August 8, 2002 |
Current U.S.
Class: |
8/158 ;
510/290 |
Current CPC
Class: |
C11D 1/83 20130101; C11D
17/0078 20130101; C11D 17/0039 20130101; C11D 3/3769 20130101; C11D
11/0017 20130101; C11D 1/02 20130101; C11D 1/66 20130101 |
Class at
Publication: |
8/158 ;
510/290 |
International
Class: |
D06B 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 13, 2001 |
GB |
0119710.2 |
Claims
1. A method of washing and rinsing a textile fabric, the method
comprising: (a) placing in a water permeable receptacle, a wash
composition and a rinse composition; (b) a washing step comprising
bringing the receptacle and the fabric into contact with a wash
liquor; and (c) subsequent to the washing step (b), a rinse step
comprising contacting the receptacle and the fabric with a rinse
liquor; wherein the rinse composition is formulated such that
release of at least some of the rinse composition is delayed until
the rinse step.
2. The method of claim 1, wherein at least the rinse composition is
provided in unit dose form.
3. The method of claim 1, wherein the water permeable receptacle
comprises a bag formed of a net material.
4. The method of claim 3, wherein the bag is provided means for
closure of the bag.
5. The method of claim 2, wherein the unit dose form of the rinse
composition comprises a component which substantially retains its
physical integrity until the rinse step and which is too large to
pass through the mesh of the net bag.
6. The method of claim 1, wherein the rinse composition comprises
one or more rinse agents selected from fabric softening agents,
antistatic agents, ease of ironing agents, anti-wrinkling/crease
protection agents, perfumes and optical brighteners.
7. The method of claim 6, wherein the rinse composition comprises a
fabric softening agent selected from cationic fabric softening
compounds, cellulases, clays and polysiloxanes and their
derivatives, and mixtures thereof.
8. The method of claim 1, wherein the rinse composition is
formulated with means for inhibiting a release of the rinse
composition during the washing step.
9. The method of claim 8, wherein the release inhibiting means
comprises a polymer, the solubility of reaching an aqueous
environment depends on the pH and/or ionic strength and/or
temperature of that environment.
10. The method of claim 9, wherein the polymer comprises monomer
units selected from one or more vinyl alcohol derivatives,
acrylates and alkylacrylates, the acrylates and/or alkylacrylates
optionally having basic functionality, said polymer optionally
being in admixture with an alkylcellulose and/or a cross-linking
agent.
11. The method of claim 9, wherein the polymer is an alkyl
substituted cellulose ether.
12. A method of rinsing a textile fabric, the method comprising;
(a) placing in a water permeable receptacle, at least one unit dose
unit comprising a rinse composition; and (b) effecting a rinse step
of contacting the water permeable receptacle and fabric with a
rinse liquor; wherein the rinse composition is formulated such that
release of substantial amount of the rinse composition cannot occur
during a prior wash step.
13. The method of claim 12, wherein a washing step is effected
prior to the rinse step, the washing step comprising contacting the
water permeable receptacle containing the unit dose unit comprising
the rinse composition with a wash liquor.
14. The method of claim 13, wherein the washing step also comprises
contacting the wash liquor with a wash composition.
15. The method of claim 14, wherein in step (a), the wash
composition is also placed in the water permeable receptacle.
16. The method of claim 14, the wash composition is provided in
unit dose form.
17. The method of claim 16, wherein the wash composition and the
rinse composition are provided in a single combined unit dose
form.
18. The method of claim 12, wherein the unit dose form(s) is or are
independently selected from tablets, water soluble sachets and
capsules.
19. The method of claim 13, wherein release of at least some of the
rinse composition is delayed until the rinse step.
20. The method of claim 12, wherein the water permeable receptacle
comprises a bag formed of a net material.
21. The method of claim 20, wherein the bag is provided means for
closure of the bag.
22. The method of claim 20, wherein the unit dose form of the rinse
composition comprises a component which substantially retains its
physical integrity until the rinse step and which is too large to
pass through the mesh of the net bag.
23. The method of claim 12, wherein the rinse composition comprises
one or more rinse agents selected from fabric softening agents,
antistatic agents, ease of ironing agents, anti-wrinkling/crease
protection agents, perfumes and optical brighteners.
24. The method of claim 23, wherein the rinse composition comprises
a fabric softening agent selected from cationic fabric softening
compounds, cellulases, clays and polysiloxanes and their
derivatives, and mixtures thereof.
25. The method of claim 12, wherein the rinse composition is
formulated with means for inhibiting a release of the rinse
composition during the washing step.
26. The method of claim 25, wherein the release inhibiting means
comprises a polymer, the solubility of reaching an aqueous
environment depends on the pH and/or ionic strength and/or
temperature of that environment.
27. The method of claim 26, wherein the polymer comprises monomer
units selected from one or more vinyl alcohol derivatives,
acrylates and alkylacrylates, the acrylates and/or alkylacrylates
optionally having basic functionality, said polymer optionally
being in admixture with an alkylcellulose and/or a cross-linking
agent.
28. The method of claim 27, wherein the polymer is an alkyl
substituted cellulose ether.
29. A unit dose product for washing and rinsing of a textile fabric
comprising a wash composition, a rinse composition and means for
inhibiting release of the rinse composition during washing, until
the rinse.
30. The unit dose product of claim 29, wherein the wash composition
and the rinse composition are located in respective separate zones
of the product.
31. The unit dose product of claim 30, wherein the zones comprise
separate zones of a tablet.
32. The unit dose product of claim 31, wherein at least the wash
composition and preferably also the rinse composition is in solid
form.
33. The unit dose product of claim 31, wherein the rinse
conditioner zone substantially retains its physical integrity until
the rinse step and has at least one dimension greater than the
average mesh size of a net or bag in which it is to be dosed.
34. The unit dose product of claim 31, wherein the rinse
composition is encapsulated in at least one polymer capsule, sachet
or gel matrix combined with the tablet.
35. The unit dose product of claim 30, wherein the zones comprise
separate zones of the water soluble sachet, preferably formed of
water soluble polymer.
36. The unit dose product of claim 35, wherein at least the wash
composition and preferably also the rinse composition is in the
form of a powder or tablet.
37. The unit dose product of claim 35, wherein the at least the
wash composition and preferably also the rinse composition is in
liquid form, especially in the form of a substantially non-aqueous
liquid.
38. The unit dose product of claim 35, wherein the separate sachet
zones comprise one sachet located inside another, the inner sachet
containing the rinse composition and the wash composition being
located between the inner and outer sachets.
39. The unit dose product of claim 34, wherein the rinse
combination is incorporated in at least polymer capsule, sachet or
gel matrix having at least one dimension, preferably a diameter,
greater than the average mesh size of a net or bag in which it is
to be dosed.
40. The unit dose product of claim 29, wherein the release
inhibiting means is pH and/or ionic strength and/or temperature
dependent.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the cleaning and rinsing of
textile fabrics, wherein both wash and rinse compositions are
placed in a wash liquor with the fabric, and then a rinsing step is
carried out in a rinse liquor, whereby release of at least some of
the rinse composition is delayed until the rinse.
BACKGROUND OF THE INVENTION
[0002] U.S. Pat. No. 4,801,636 discloses a comminuted wash additive
in a water soluble polymeric film envelope or in microcapsules of
the water soluble polymer, or in a water-insoluble envelope sealed
with the water soluble polymer. The water soluble polymer typically
comprises polyvinyl alcohol and alkyl cellulose monomer units
together with a cross-linking agent. The polymer is insoluble at
higher pH but becomes increasingly soluble as the pH is
reduced.
[0003] It is also known from U.S. Pat. No. 4,108,600 to coat fabric
conditioner particles with a coating, the solubility of which is pH
dependent. The coating comprises a water soluble polymer,
preferably a polyvinyl alcohol or gelatin of defined molecular
weight and isoelectric point. These particles have a particle size
up to about 1,500 microns and are disposed in a porous receptacle
having porous openings which are smaller than the particle size
e.g., up to 120 microns. A pH control agent (insolubilising agent)
is kept separate from the coated fabric conditioner particles, e.g.
in a separate receptacle or separate compartment of the same
receptacle. Typical pH control agents are common organic or
inorganic acids, bases or buffering agents.
[0004] The delayed release of a fabric softening clay component
into the wash liquor, from a detergent tablet containing a washing
composition, is disclosed in WO-A-99/40171, although delay until
the rinse cycle is not envisaged.
[0005] It has now been found possible to utilise formulations
adapted for delayed release in the rinse, in such a way as to
improve delivery of the product into the process. This has been
achieved by formulating a delayed release rinse composition in unit
dose form and to be dosed in a receptacle such as a net bag and/or
by also dosing the main wash composition in that receptacle, into
the washing machine or other wash environment.
[0006] EP-A-343 069 discloses dosing of a detergent powder in a net
bag in top-loading washing machines to prevent premature
flushing-away of the product.
[0007] The dosing of laundry detergent tablets into a washing
machine by means of a net bag is known from GB-A-2 345 920 and
EP-A-0 964 951. The drawings in the first of these appear to depict
a two-layer tablet.
[0008] Definition of the Invention
[0009] Thus, in a first aspect, the present invention provides a
method of washing and rinsing a textile fabric, the method
comprising:
[0010] (a) placing in a water permeable receptacle, a wash
composition and a rinse composition;
[0011] (b) a washing step comprising bringing the receptacle and
the fabric into contact with a wash liquor; and
[0012] (c) subsequent to the washing step (b), a rinse step
comprising contacting the receptacle and the fabric with a rinse
liquor;
[0013] wherein the rinse composition is formulated such that
release of at least some of the rinse composition is delayed until
the rinse step.
[0014] A second aspect of the present invention provides a method
of rinsing a textile fabric, the method comprising;
[0015] (a) placing in a water permeable receptacle, at least one
unit dose unit comprising a rinse composition; and
[0016] (b) effecting a rinse step of contacting the water permeable
receptacle and the fabric with a rinse liquor;
[0017] wherein the rinse composition is formulated such that
release of a substantial amount of rinse composition cannot occur
during a prior wash step.
[0018] A third aspect of the present invention provides a unit dose
product for washing and rinsing of a textile fabric comprising a
wash composition, a rinse composition and means for inhibiting
release of the rinse composition during washing, until the
rinse.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Unit Dose Forms
[0020] Suitable unit dose forms include tablets, water soluble
sachets and water soluble capsules. Each can be made by a specific
technology. Tablets are suitable for solid compositions whereas,
sachets and capsules are suitable for solid or liquid compositions,
although in the later case, some care has to be taken to ensure
long term stability of the composition with the material used to
form the tablet, sachet or capsule.
[0021] As mentioned above, dosing of delayed release coated
particles up to 1,500 microns in a water permeable receptacle is
known from U.S. Pat. No. 4,108,600. A unit dose certainly has at
least one dimension (e.g. diameter, length, width or height),
greater than 1,500 microns but preferably at least 0.5 cm, more
preferably at least 1 cm, for example no more than 5 cm, preferably
no more than 2.5 cm.
[0022] However, it is preferred that the delayed release rinse
composition is formulated as a component such as a tablet layer,
capsule(s) (whether such capsule is free or incorporated in a
tablet layer), a sachet or gel matrix which substantially sustains
its physical integrity until the rinse step and has a size large
enough not to pass through mesh of a net or bag which constitutes
the water permeable receptacle. In the case of a whole tablet layer
or non-spherical capsule, preferably it has at least one dimension
greater than the mesh size. In the case of a capsule which is
substantially spherical, preferably its diameter is greater than
the mesh size.
[0023] (a) Tablets
[0024] Tableting Entails Compaction of a Particulate
Composition.
[0025] A variety of tableting machinery is known, and can be used.
Generally it will function by stamping a quantity of the
particulate composition which is confined in a die.
[0026] Tableting machinery able to carry out such operations is
known. For example, suitable tablet presses are available from
Fette and from Korsch.
[0027] Tableting may be carried out at ambient temperature or at a
temperature above ambient which may allow adequate strength to be
achieved with less applied pressure during compaction. In order to
carry out the tableting at a temperature which is above ambient,
the particulate composition is preferably supplied to the tableting
machinery at an elevated temperature. This will of course supply
heat to the tableting machinery, but the machinery may be heated in
some other way also.
[0028] It is known to make tablets using microwave radiation. WO
96/06156 mentions that hydrated materials are useful in this
special circumstance to cause sintering.
[0029] For the present invention, if any heat is supplied, it is
envisaged that this will be supplied conventionally, such as by
passing the particulate composition through an oven, rather than by
any application of microwave energy.
[0030] The size of a tablet will suitably range from 10 to 160
grams (gm), preferably from 15 to 60 gm, depending on the
conditions of intended use, and whether the tablet represents a
dose for an average load in a fabric washing or a fractional part
of such a dose. The tablets may be of any shape. However, for ease
of packaging they are preferably blocks of substantially uniform
cross-section, such as cylinders or cuboids.
[0031] The overall density of a tablet is preferably 1040 or 1050
gm/liter, better 1100 gm/liter, up to 1300 or 1350 gm/liter or even
more. The tablet density may well lie in a range up to no more than
1250 or even 1200 gm/liter.
[0032] Thus the starting particulate composition may suitably have
a bulk density of at least 400 g/liter, preferably at least 500
g/liter, and advantageously at least 700 g/liter. Granular
detergent compositions of high bulk density prepared by granulation
and densification in a high-speed mixer/granulator, as described
and claimed in EP 340013A (Unilever), EP 352135A (Unilever), and EP
425277A (Unilever), or by the continuous granulation/densification
processes described and claimed in EP 367339A (Unilever) and EP
390251A (Unilever), are inherently suitable for use in the present
invention.
[0033] Tablets in which the rinse composition is held in a central
cavity (the body of the tablet) containing a wash composition may
be formed using an appropriately shaped die.
[0034] (b) Sachets
[0035] Sachets may be water permeable envelopes made of woven or
non woven fabric. Preferably, however, they are formed of water
soluble polymer.
[0036] The envelope forming the sachet is most preferably formed by
horizontal or vertical form-film-seal of a water soluble polymer
film. The film preferably incorporates a stabilizer.
[0037] As will be elucidated in more detail hereinbelow, the water
soluble film may be formed from a variety of different materials.
The plasticiser will depend on the nature of the film in question.
Therefore, preferred plasticisers will be recited in more detail in
the section of this description dealing with these film materials.
However, the preferred amount of plasticiser is from 0.2% to 40%,
preferably from 10% to 20% by weight of the substantially
non-aqueous liquid composition. One or more plasticisers may
independently be incorporated in the film and in the liquid
composition.
[0038] However, it is preferred for the identity of the
plasticiser(s) in the film and in the liquid composition to be
substantially the same.
[0039] The plasticiser system influences the way the polymer chains
react to external factors such as compression and extensional
forces, temperature and mechanical shock by controlling the way
that the chains distort/realign as a consequences of these
intrusions and their propensity to revert or recover to their
former state. The key feature of plasticisers is that they are
highly compatible with the film, and are normally hydrophilic in
nature.
[0040] As used herein, the term "water soluble polymer" refers to a
polymer which dissolves and dispenses completely in water within 5
minutes with agitation, e.g. by means of hand, stick or other
stirrer or under the action of a mechanical washing machine and at
a relevant temperature. A "relevant temperature" is one at which
the consumer will need to dissolve or disperse the polymer
component at the beginning of, or during a cleaning process. A
polymer is to be regarded as dissolving or dispersing at a
"relevant temperature" if it does so under the aforementioned
conditions at a temperature anywhere in the range of from
20.degree. C. to 60.degree. C.
[0041] Preferred water soluble polymers are those capable of being
cast into a film or solid mass and may for example as described in
Davidson and Sittig, Water-Soluble Resins, Van Nostrand Reinhold
Company, New York (1968). The water-soluble polymer should have
proper characteristics, such as strength and pliability, to permit
machine handling. Preferred water-soluble resins include polyvinyl
alcohol, cellulose ethers, polyethylene oxide, starch,
polyvinylpyrrolidone, polyacrylamide, polyvinyl methyl ether-maleic
anhydride, polymaleic anhydride, styrene maleic anhydride,
hydroxyethylcellulose, methylcellulose, polyethylene glycols,
carboxymethylcellulose, polyacrylic acid salts, alginates,
acrylamide copolymers, guar gum, casein, ethylene-maleic anhydride
resin series, polyethyleneimine, ethyl hydroxyethylcellulose, ethyl
methylcellulose, hydroxyethyl methylcellulose or blends of polymers
mentioned above. Lower molecular weight water-soluble, polyvinyl
alcohol film-forming resins are preferred.
[0042] Generally, preferred water-soluble, polyvinyl alcohol
film-forming polymers should have relatively low average molecular
weight and low levels of hydrolysis in water. Polyvinyl alcohols
preferred for use therein have a weight average molecular weight
between 1,000 and 300,000, preferably between 2,000 and 200,000,
most preferably between 30,000 and 150,000. Hydrolysis, or
alcoholysis, is defined as the percent completion of the reaction
where acetate groups on the resin are substituted with hydroxyl,
--OH, groups, A hydrolysis range of from 60-99% of polyvinyl
alcohol film-forming resin is preferred, while a more preferred
range of hydrolysis is from about 70-95% for water-soluble,
polyvinyl alcohol film-forming resins. The most preferred range of
hydrolysis is 80-92%. As used in this application, the term
"polyvinyl alcohol" includes polyvinyl acetate compounds with
levels of hydroloysis disclosed herein. The water-soluble resin
film should be formulated so as to substantially completely
dissolve in 130.degree. F. water with agitation within about five
minutes, preferably within about 3 minutes in 100.degree. F. water
with agitation, and most preferably within about 1 minute in
100.degree. F. water with agitation.
[0043] All of the above polymers include the aforementioned polymer
classes whether as single polymers or as copolymers formed of
monomer units or as copolymers formed of monomer units derived from
the specified class or as copolymers wherein those monomer units
are copolymerised with one or more comonomer units.
[0044] A preferred plastics film is a polyvinyl alcohol film,
especially one made of a polyvinyl alcohol copolymer having a
comonomer having a carboxylate function.
[0045] PVA can be made by the polymerisation of vinyl acetate,
followed by hydrolysis, conveniently by reaction with sodium
hydroxide. However, the resulting film has a highly symmetrical,
hydrogen-bonded structure and depends on the particular PVA
composition, is not necessarily readily soluble in cold water. PVA
films which are suitable for the formation of water soluble
packages are typically polymers produced from copolymerisation of
vinyl acetate and another comonomer which contains a carboxylic
function. Examples of such comonomers include monocarboxylates,
such as acrylic acid, and dicarboxylates, such as itaconic acid,
which may be present during polymerisation as esters.
Alternatively, the anhydride of maleic acid may be used as the
copolymer. The inclusion of the comonomer reduces the symmetry of
and degree of hydrogen bonding in the final film and renders the
film soluble even in cold water. Partially hydrolysed PVA can also
be used to deliberately adapt the film to be cold water
soluble.
[0046] Suitable PVA films for use in a package according to the
invention are commercially available and described, for example, in
EP-B-0 291 198. PVA films for use in a package according to the
invention can be made by the copolymerisation of vinyl acetate and
a carboxylate-containing monomer (for example acrylic, maleic or
itaconic acid or acid ester), followed by either partial (for
example up to about 90%) or complete hydrolysis with sodium
hydroxide.
[0047] In order to make the water solubility of PVA ionic strength
and/or pH dependent, so it is soluble in the rinse liquor but not
in the wash liquor, it may be blended with one or more other
substances, e.g. with an alkyl cellulose and a metallic
cross-linker such as a boron compound, as described in U.S. Pat.
No. 4,801,636.
[0048] Plasticizers can be included in the polymer to improve the
physical stability of the film. The preferred amount of plasticiser
is from 0.2% to 20%, preferably from 5% to 10% by weight of the
substantially non-aqueous liquid composition.
[0049] Generally speaking, plasticisers suitable for use with
PVA-based films have --OH groups in common with the
.about.CH2--CH(OH)--CH2--CH(OH)- -polymer chain of the film
polymer.
[0050] Their mode of functionality is to introduce short chain
hydrogen bonding with the chain hydroxyl groups and thus weaken
adjacent chain interactions which inhibits swelling of the
aggregate polymer mass--the first stage of film dissolution.
[0051] Water itself is a suitable plasticiser for PVOH films but
other common plasticisers include:
[0052] Polyhydroxy compounds, e.g. glycerol, trimethylolpropane,
diethylene glycol, triethylene glycol, dipropylene glycol,
sorbitol
[0053] Starches e.g. starch ether, esterificated starch, oxidized
starch and starches from potato, tapioca and wheat
[0054] Cellulosics/carbohydrates, e.g. amylopectin, dextrin
carboxymethylcelluose and pectin.
[0055] Polyvinylpyrrolidone (PVP), another preferred polymer for
use in the articles of the present invention, may be cast from a
variety of solvents to produce films which are clear, glossy, and
reasonably hard at low humidities. These polyvinylpyrrolidone films
exhibit excellent adhesion to a wide variety of surfaces, including
glass, metals, and plastics. Unmodified films of
polyvinylpyrrolidone are hygroscopic in character. Dry
polyvinylpyrrolidone film has a density of 1.25 and a refractive
index of 1.53. Tackiness at higher humidities may be minimized by
incorporating compatible, water-insensitive modifiers into the
polyvinylpyrrolidone film, such as 10% of an
aryl-sulfonamide-formaldehyd- e resin.
[0056] Suitable plasticisers for PVP-based films may be chosen from
one or more of those specified above for PVA.
[0057] Preferred water-soluble films may also be prepared from
polyethylene oxide (PEO) resins by standard calendering, molding,
casting, extrusion, and other conventional techniques. The
polyethylene oxide films may be clear or opaque, and are inherently
flexible, tough, and resistant to most oils and greases. These
polyethylene oxide resin films provide better solubility than other
water-soluble plastics without sacrificing strength or toughness.
The excellent ability to lay flat, stiffness, and sealability of
water-soluble polyethylene oxide films make for good machine
handling characteristics.
[0058] Suitable plasticisers for PEO-based films may be selected
from one or more of those specified for PVA and PVP.
[0059] Sachet Forming Methods
[0060] Horizontal Form-Fill-Seal
[0061] Water soluble based on PVA can be made according to any of
the methods horizontal form-fill-seal described in any of
WO-A-00/55044, WO-A-00/55045, WO-A-00/55046, WO-A-00/55068,
WO-A-00/55069 and WO-A-00/55415.
[0062] By way of example, a thermoforming process is now described
where a number of packages according to the invention are produced
from two sheets of water soluble material. In this regard recesses
are formed in the film sheet using a forming die having a plurality
of cavities with dimensions corresponding generally to the
dimensions of the packages to be produced. Further, a single
heating plate is used for thermoforming the film for all the
cavities, and in the same way a single sealing plate is
described.
[0063] A first sheet of polyvinyl alcohol film is drawn over a
forming die so that the film is placed over the plurality of
forming cavities in the die. In this example each cavity is
generally dome shape having a round edge, the edges of the cavities
further being radiussed to remove any sharp edges which might
damage the film during the forming or sealing steps of the process.
Each cavity further includes a raised surrounding flange. In order
to maximise package strength; the film is delivered to the forming
die in a crease free form and with minimum tension. In the forming
step, the film is heated to 100 to 120.degree. C., preferably
approximately 110.degree. C., for up to 5 seconds, preferably
approximately 700 micro seconds. A heating plate is used to heat
the film, which plate is positioned to superpose the forming die.
During this preheating step, a vacuum of 0.5 bar is pulled through
the pre-heating plate to ensure intimate contact between the film
and the pre-heating plate, this intimate contact ensuring that the
film is heated evenly and uniformly (the extent of the vacuum is
dependant of the thermoforming conditions and the type of film
used, however in the present context a vacuum of less than 0.6 bar
was found to be suitable). Non-uniform heating results in a formed
package having weak spots. In addition to the vacuum, it is
possible to blow air against the film to force it into intimate
contact with the preheating plate.
[0064] The thermoformed film is moulded into the cavities blowing
the film off the heating plate and/or by sucking the film into the
cavities thus forming a plurality of recesses in the film which,
once formed, are retained in their thermoformed orientation by the
application of a vacuum through the walls of the cavities. This
vacuum is maintained at least until the packages are sealed. Once
the recesses are formed and held in position by the vacuum, a
liquid composition according to the invention is added to each of
the recesses. A second sheet of polyvinyl alcohol film is then
superposed on the first sheet across the filled recesses and
heat-sealed thereto using a sealing plate. In this case the heat
sealing plate, which is generally flat, operates at a temperature
of about 140 to 160.degree. C., and contacts the films for 1 to 2
seconds and with a force of 8 to 30 kg/cm.sup.2, preferably 10 to
20 kg/cm.sup.2. The raised flanges surrounding each cavity ensure
that the films are sealed together along the flange to form a
continuous seal. The radiussed edge of each cavity is at least
partly formed by a resiliently deformable material, such as for
example silicone rubber. This results in reduced force being
applied at the inner edge of the sealing flange to avoid
heat/pressure damage to the film.
[0065] Once sealed, the packages formed are separated from the web
of sheet film using cutting means. At this stage it is possible to
release the vacuum on the die, and eject the formed packages from
the forming die. In this way the packages are formed, filled and
sealed while nesting in the forming die. In addition they may be
cut while in the forming die as well.
[0066] During the forming, filling and sealing steps of the
process, the relative humidity of the atmosphere is controlled to
ca. 50% humidity. This is done to maintain the heat sealing
characteristics of the film. When handling thinner films, it may be
necessary to reduce the relative humidity to ensure that the films
have a relatively low degree of plasticisation and are therefore
stiffer and easier to handle.
Vertical Form-Fill-Seal
[0067] In the vertical form-fill-seal (VFFS) technique, a
continuous tube of flexible plastics film is extruded. It is
sealed, preferably by heat or ultrasonic sealing, at the bottom,
filled with the liquid composition, sealed again above the liquid
film and then removed from the continuous tube, e.g. by
cutting.
[0068] Encapsulation methods for other water soluble films such as
based on PVP or PEO will be known to those skilled in the art.
[0069] The way that the chains distort/realign as a consequences of
these intrusions and their propensity to revert or recover to their
former state. The key feature of plasticisers is that they are
highly compatible with the film, and are normally hydrophilic in
nature.
[0070] (c) Capsules
[0071] Capsules may be made of, for example, gelatin or starch but
are preferably based on water soluble polymers used to encapsulate
the material in question
[0072] The material may typically be formed as a granule or bolus
and coated by a process is fluidised-bed coating or agglomeration.
Other useful options are pan coating, dip coating or rotating disk
coating. In these cases the core material may be a capsule, a
tablet, or any other form of the material to be encapsulated
material may also be encapsulated via film coating.
[0073] Delayed Release
[0074] In the first embodiment of the present invention, the rinse
composition must be provided in a form such that release of at
least some of the rinse composition is delayed until the rinse
step. This is also the case in preferred embodiments of the second
invention. It generally entails controlled/triggered release,
depending on some parameter which changes between the wash and
rinse.
[0075] Release inhibition for the rinse composition can be
controlled by various physical chemical triggers like temperature,
pH, ionic strength, Ca.sup.2+-level, osmotic pressure or changes in
the concentration of soluble components of wash compositions, e.g.
Na.sup.+ level, due to dissolution in the rinse. Alternatively,
release inhibition could be controlled by enzyme release in the
rinse phase, the spinning motion or time. Combinations of triggers
mentioned above can be used.
[0076] Release inhibiting means for preventing release of the rinse
composition is preferably pH and/or ionic strength and/or
temperature dependent. The pH in the wash liquor is usually high,
i.e. at least 9.5, especially at least 10. However, in the rinse
liquor, the pH is usually much lower, i.e. no more than 9,
typically no more than 8.5. The ionic strength of the wash liquor
is usually at least 4 mS/cm, especially at least 4.5 mS/cm. In the
rinse liquor, the ionic strength is lower, at the most 2.5 mS/cm,
especially lower than 1.5 mS/cm.
[0077] Typical pH and/or ionic strength dependent release
inhibiting means may form all or part of any material used to
encapsulate the rinse composition or form a sachet containing the
rinse composition, or be mixed in a matrix with the rinse
conditioner in powder or granular form.
[0078] One preferred form of water soluble polymer, the solubility
of which is ionic strength and pH dependent, is a polymer made from
vinyl alcohol monomer units, optionally also with one or more other
comomoner units such as alkyl cellulose or carboxyl functional
monomers such as acrylic, maleic or itaconic acids or the
equivalent acid esters thereof. As already described, these kinds
of polymers are suitable for making sachets from films of those
polymers.
[0079] In one preferred class of embodiments, the polymer comprises
monomers units selected from one or more vinyl alcohol derivatives,
acrylates and alkylacrylates, the acrylates and/or alkylacrylates
optionally having basic functionality, said polymer optionally
being in admixture with an alkylcellulose and/or a cross-linking
agent. Another preferred class is when the polymer is an alkyl
substituted cellulose ether. However, other preferred forms of
polymer for the delayed release function will now be given.
[0080] The pH dependence of the solubility of such a polymer may be
brought about by incorporation therein of a cross-linking agent of
the kind described in U.S. Pat. No. 4,801,636. These are so-called
"metallic" cross-linking agents.
[0081] A preferred "metallic" cross-linking agent comprising boric
acid and its salt. Other potential cross-linkers are for example
tellluric and arsenic acid precursors and salts thereof.
Derivitised metalloid oxides may also be possible. Even more
cross-linkers are given in the book: "Polyvinylalcohol--Properties
and applications, Chapter 9 by C. A. Finch (John Wiley & Sons,
New York, 1973"). The cross-linking agent can be present in the
polymer itself and/or as or part of another component in the same
or another composition used at the same time.
[0082] The polymeric material and cross-linking may be in contact
with a cationic species having a hydrophobic group. The cationic
species may be present in the aqueous wash liquid or can be added
to the film or additive materials. Such cationic species may
comprise organonitrogen salts, organophosphorous salts, cationic
organic sulphonium salts, cationic organic tin compounds,
amphoteric surfactants and the like. The organic groups or such
salts may be alkyl, aryl, alkenyl or combinations thereof.
Quaternary ammonium compounds are the preferred cationic species.
For example in the presence of cetyl pyridinium chloride (at a
concentration of 0.1% wt %), the dissolution rates of the PVA/alkyl
cellulose decrease by a factor of 32 at high borate
concentration/high pH, while only by a factor of 3 at low borate
ion concentration/low pH.
[0083] A surfactant may be added to the polymer as anti-foam and as
a wetting agent. Virtually any surfactant known in the art is
suitable for this purpose. Non-limiting examples include
ethoxylated aliphatic alcohols, ethoxylated alkylphenols, polyols
and C.sub.6-10 aliphatic alcohols. Other examples are polyethylene
glycol ether and octyl alcohol.
[0084] Other materials, including polymers, the solubility or
dispersability of which in an aqueous medium is pH dependent, may
be chosen from the following:
[0085] (i) JP-A-60 141 705 discloses a copolymer characterised in
that a basis monomer (A) represented by the formula:
CH.sub.2.dbd.C(R)COOCH.sub.2CH.sub.2N(R.sup.1)R.sup.2
[0086] (in which R is a hydrogen or a methyl group, and R.sup.1 and
R.sup.2 each is an alkyl group having 1-3 carbons), a monomer (B)
which is insoluble or hardly soluble in water and a monomer (C)
which is soluble in water are copolymerised in such a manner that
the amount of (A) is 10-65% by weight, the amount of (B) is 8-45%
by weight and the ratio by weight of (B)/(C) is from 2/1 to
1/7.
[0087] This polymer is substantially insoluble in alkaline water of
pH of about 9.5 or higher while it is soluble in water of pH of
about 8.5 or lower. The ratio between the dissolving time above a
pH of 9.5 and that below a pH of 8.5 is large.
[0088] The insoluble monomer (A) is a main monomer component for
preparing such pH sensitive copolymers and may for example be
selected from from N--N-dimethylamino ethyl acrylate,
N,N-dimethylamino ethyl acrylate, N,N-dimethylamino ethyl
methacrylate, N,N-dimethylamino ethyl acrylate, N--N-diethylamino
ethyl methacrylate and mixtures thereof.
[0089] Examples for the insoluble monomer (B) are acrylic acid
ester, methacrylic acid ester, crotonic acid ester, itaconic acid
ester, vinylacetate and styrene. It is preferred that the carbon
number of the alkyl group which is ester bonded is from 1 to 8.
Methyl acrylate, ethyl acrylate, butyl acrylate, methyl
methacrylate and ethyl methacrylate and the particularly preferred
examples.
[0090] Water soluble monomer (C) can be selected from
N,N-dimethylaminopropylacrylic acid (or methacrylic acid) amide,
N,N-d-dimethylacrylic acid (or methacrylic acid) amide,
2-hydroxyethyl acrylate (or methacrylate), 2-hydroxypropyl acrylate
(or methacrylate) and an ester of acrylic acid or methacrylic acid
with polyethylene glycol or methoxypolyethylene glycol
(p=2.about.30).
[0091] (ii) WO-A-00/17311 discloses a material which has a melting
point no less than 30.degree. C. and a pKa of no more than 12 and
no less than 7.0, preferably between 11.5 and 8.0, most preferably
between 10.5 and 9.0. The preferred material is selected so that
during the early part of the wash where the was solution pH is
controlled by the detergent around 10, the coating material is
substantially neutral without charge and remains relatively water
insoluble. During the rinse the material will be protonated to
become positively charged and more water soluble.
[0092] Preferred coating materials are, amines, waxes, Schiff base
compounds and mixtures thereof. Preferred amines include other than
primary fatty amines. Such amines include polymeric aminofunctional
homopolymers and/or copolymers and/or ter-polymers. The preferred
amines typically do not have exclusively primary amino
functionality, rather they typically contain secondary and/or
tertiary amino groups, optionally with primary amino moieties also
included.
[0093] Waxes can be used as a co-melted blend to improve the
filming property. The preferred ratio of wax to amines is no more
than 50% wax.
[0094] An alternate class of such materials are Schiff bases, i.e.
adduct of amines with aldehydes. Only selected types break down at
the pH of the current invention. One example is formed between
p-amino benzoate with an alkyl aldehyde. A preferred example is the
Schiff base made by fusing p-amino benzote with a n-dodecyl
aldehyde.
[0095] (iii) WO00/06683 discloses a material which includes at
least one compound which is not or only slightly soluble at the end
of the main wash cycle of the washing machine (at pH above 10). In
the rinsing processes (pH less than 9), however it is dissolved or
detached from the nucleus (from the nuclei) to such an extent that
at least a partial discharge of the nucleus material takes place.
This compound preferably includes a polymer, especially a
pH-sensitive polymer, which includes at least one repeating unit,
which has at least one basic function, which does not form part of
the backbone chain of the polymer. In a preferred implementation
the polymer includes at least one repeating unit, which is based on
a compound, which has been selected from the group which consists
of vinylalcoholderivatives, acrylates or alkylacrylates which
include said basic function. In a special implementation of the
invention the polymer is carbohydrate which has been functionalised
with said basic function.
[0096] In an alternative implementation the repeating unit is based
on a compound with the following formula: 1
[0097] where G is a connecting group which has been selected from
--COO--, OCO--, CONH--, --NHCO--, NHCONH--, --NHCOO--, --OCONH-- or
--OCOO--, R.sup.1 independently of each other is hydrogen or an
alkyl group with 1-3 carbon atoms, R.sup.2 independent of each
other is hydrogen or an alkyl group with 1-5 carbon atoms and x is
an integer between 1 and 6.
[0098] Preferably, the repeating unit is based on a compound with
the following formula IV: 2
[0099] where R.sub.1 independent of each other is hydrogen or an
alkyl group with 1-3 carbon atoms, R.sub.2 independent of each
other is hydrogen or an alkyl group with 1-5 carbon atoms and x is
an integer between 1 and 6.
[0100] Alternatively, a pH sensitive polymer sold as AEA.TM. ex
Sankyo, and having the following formula, may be used: 3
[0101] In other variants, the basic function is an imine or a basic
aromatic N-containing group, preferably a pyridine group or an
imidazole group or the pH-sensitive component is a polymer
obtainable from Chitosan, or the material may contain
K-Carrageenan.
[0102] (iv) An example of a material that can inhibit dissolution
of the rinse material during the main wash, is polyvinyl
caprolactam or hydroxybutylmethylcellulose. Those materials are
insoluble at temperatures above 35.degree. C., but become soluble
in the rinse phase, when water of ambient temperature is introduced
in the washing machine.
[0103] (v) Additional mechanisms of release inhibition in the wash
solution, followed by triggered release in the rinse, are described
in WO-A-014421, WO-A-014433, WO-A-014434, WO-A-014435, or DE-A-10
00 34 29.
[0104] The Water Permeable Receptacle
[0105] The water permeable receptacle is intended to retain the
contents thereof during the wash and rinse steps whilst allowing
the contents to be wetted by the wash or rinse water or liquor,
such that at the relevant time, they may be released by dispersion
and/or dissolution.
[0106] Although such a receptacle may be formed of a non-woven
fabric, preferably it is formed from a woven material, for example
a coarse-woven cloth or net. Such a material should have a mesh
size which is significantly smaller than the intended contents. As
mentioned above, preferably the mesh size should be larger than at
least one dimension of any component such as a tablet layer,
capsule (whether free or incorporated in a tablet layer), sachet or
gel matrix which constitutes a unitary delayed release rinse
conditioner component which substantially retains its physical
integrity until the rinse step. Substantially spherical such
capsules, whether separate or incorporated in a tablet layer,
preferably have a diameter larger than the mesh size. Mesh sizes of
at least 3 mm, preferably around 5 mm, e.g. up to 7.5 mm are
typical.
[0107] The Rinse Composition
[0108] Use of a rinse composition is essential to the first aspect
of the present invention and preferably for the second aspect of
the invention.
[0109] The rinse composition contains at least one agent which
exerts a beneficial action upon a textile in the rinse. Suitable
examples of such agents include fabric softening agents, especially
cationic softening compounds, antistatic agents, ease of ironing
agents, anti-wrinkling/crease protection agents, perfume and
optical brighteners. Alternatively, delayed release by means of the
invention is also beneficial for e.g. oxygen bleach, bleach
activators, soil release agent, enzymes, suds supressors,
disinfectants, anti-redeposition aids, dye transfer inhibitors.
[0110] A discussion of materials which are known as fabric
softening agents and which may be used in the tablets of the
present invention is found in published International Patent
Application WO-A-94/24999.
[0111] Some suitable softeners are cationic softening components,
optionally used together with other materials such as oily sugar
derivatives, formulation and dispersion aids,
anti-oxidation/reduction stabilisers and co-active softening
surfactants; cellulases; clays; and polysiloxanes and their
derivatives. Mixtures of any of the foregoing can also be used.
[0112] (a) Cationic Fabric Softening Compounds
[0113] Suitable cationic fabric softening compounds may be selected
from those typically included in rinse-added fabric softening
compositions.
[0114] It is especially preferred if the cationic softening agent
is a water insoluble quaternary ammonium material which comprises a
compound having two C.sub.12-18 alkyl or alkenyl groups connected
to the nitrogen head group via at least one ester link. It is more
preferred if the quaternary ammonium material has two ester
links.
[0115] A first preferred type of ester-linked quaternary ammonium
material is represented by formula (I): 4
[0116] each R.sup.1 group is independently selected from C.sub.1-4,
alkyl or hydroxyalkyl or C.sub.2-4 alkenyl groups; and wherein each
R.sup.2 group is independently selected from C.sub.8-28 alkyl or
alkenyl groups; X.sup.-- is any suitable anion including a halide,
acetate or lower alkosulphate ion, such as chloride or
methosulphate, n is 0 or an integer from 1 to 5, and m is an
integer from 1 to 5.
[0117] Preferred materials of this class such as 1,2 bis[hardened
tallowoyloxy]-3-trimethylammonium propane chloride and their method
of preparation are, for example, described in U.S. Pat. No.
4,137,180 (Lever Brothers). Preferably these materials comprise
small amounts of the corresponding monoester as described in U.S.
Pat. No. 4,137,180for example 1-hardened tallowoyloxy -2-hydroxy
3-trimethylammonium propane chloride.
[0118] A second type of ester-linked quaternary ammonium material
is represented by the formula (II): 5
[0119] wherein T, R.sup.1, R.sup.2, n, and X.sup.-- are as defined
above.
[0120] Especially preferred materials within this formula are
di-alkenyl esters of triethanol ammonium methyl sulphate and
N--N-di(tallowoyloxy ethyl) N,N-dimethyl ammonium chloride.
Commercial examples of compounds within this formula are
Tetranyl.RTM. AOT-1 (di-oleic ester of triethanol ammonium methyl
sulphate 80% active), AO-1(di-oleic ester of triethanol ammonium
methyl sulphate 90% active), AHT-1 (di-hardened oleic ester of
triethanol ammonium methyl sulphate 90% active), L1/90 (partially
hardened tallow ester of triethanol ammonium methyl sulphate 90%
active), L5/90 (palm ester of triethanol ammonium methyl sulphate
90% active (supplied by Kao corporation) and Rewoquat WE15
(C.sub.10-C.sub.20 and C.sub.16-C.sub.18 unsaturated fatty acid
reaction products with triethanolamine dimethyl sulphate
quaternised 90% active), ex Witco Corporation.
[0121] A third preferred type of quaternary ammonium material is
represented by formula (III) 6
[0122] where R.sub.1 and R.sub.2 are C.sub.8-28 alkyl or alkenyl
groups; R.sub.3 and R.sub.4 are C.sub.1-4 alkyl or C.sub.2-4
alkenyl groups and X.sup.-- is as defined above.
[0123] Examples of compounds within this formula include di(tallow
alkyl)dimethyl ammonium chloride, di(tallow alkyl) dimethyl
ammonium methyl sulphate, dihexadecyl dimethyl ammonium chloride,
di(hardened tallow alkyl) dimethyl ammonium chloride, dioctadecyl
dimethyl ammonium chloride and di(coconut alkyl) dimethyl ammonium
chloride.
[0124] It is advantageous for environmental reasons if the
quaternary ammonium material is biologically degradable.
[0125] Preferably, the compositions are provided as
superconcentrates comprising from 25-97% by weight of cationic
surfactant (active ingredient) based on the total weight of the
composition, more preferably 35-95% by weight, most preferably
45-90% by weight, e.g. 55-85% by weight.
[0126] If the quaternary ammonium softening agent comprises
hydrocarbyl chains formed from fatty acids or fatty acyl compounds
which are unsaturated or at least partially unsaturated (e.g.
having an iodine value of from 5 to 140, preferably 5 to 100, more
preferably 5 to 60, most preferably 5 to 40, e.g. 5 to 25), then
the cis:trans isomer weight ratio in the fatty acid/fatty acyl
compound is greater than 20:80, preferably greater than 30:70, more
preferably greater than 40:60, most preferably greater than 50:50,
e.g. 70:30 or greater. It is believed that higher cis:trans isomer
weight ratios afford the compositions comprising the compound
better low temperature stability and minimal odour formation.
Suitable fatty acids include Radiacid 406, ex Fina. Saturated and
unsaturated fatty acids/acyl compounds may be mixed together in
varying amounts to provide a compound having the desired iodine
value.
[0127] Fatty acids/acyl compounds may also be, at least partially
hydrogenated to achieve lower iodine values.
[0128] Of course, the cis:trans isomer weight ratios can be
controlled during hydrogenation by methods known in the art such as
by optimal mixing, using specific catalysts and providing high
H.sub.2 availability.
[0129] For improved rapid dispersion and/or dissolution of the
composition after its release from the water soluble package, it is
preferred that the fatty acyl compounds or fatty acids from which
the softening compound is formed have an iodine value of from 5 to
140, more preferably 10 to 100, most preferably 15 to 80, e.g. 25
to 60.
[0130] Iodine Value of the Parent Fatty Acid
[0131] In the context of the present invention, iodine value of the
parent fatty acid of the cationic surfactant is defined as the
number of grams of iodine which react with 100 grams of
compound.
[0132] To calculate the iodine value of a parent fatty acid of a
cationic surfactant, a prescribed amount (from 0.1-3 g) of the
fatty acid was dissolved into about 15 ml chloroform. The dissolved
parent fatty acid was then reacted with 25 ml of iodine
monochloride in acetic acid solution (0.1M). To this, 20 ml of 10%
potassium iodide solution and about 150 ml deionised water was
added. After addition of the halogen to the parent fatty acid had
taken place, the excess of iodine monochloride was determined by
titration with sodium thiosulphate solution (0.1M) in the presence
of a blue starch indicator powder. At the same time a blank was
determined with the same quantity of reagents and under the same
conditions. The difference between the volume of sodium
thiosulphate used in the blank and that used in the reaction with
the parent fatty acid enabled the iodine value to be
calculated.
[0133] Oily Sugar Derivatives
[0134] The rinse conditioner may comprise an oily sugar
derivative.
[0135] The oily sugar derivative is a liquid or soft solid
derivative of a cyclic polyol or of a reduced saccharide, said
derivative resulting from 35 to 100% of the hydroxyl groups in said
polyol or in said saccharide being esterified or etherified. The
derivative has two or more ester or ether groups independently
attached to a C.sub.8-C.sub.22 alkyl or alkenyl chain.
[0136] The oily sugar derivatives of the invention is also referred
to herein as "derivative-CP" and "derivative-RS" dependant upon
whether the derivative is the product derived from a cyclic polyol
or from a reduced saccharide starting material respectively.
[0137] Preferably the derivative-CP and derivative-RS contain 35%
by weight tri or higher esters, eg at least 40%.
[0138] Preferably 35 to 85% most preferably 40 to 80%, even more
preferably 45 to 75%, such as 45 to 70% of the hydroxyl groups in
said cyclic polyol or in said reduced saccharide are esterified or
etherified to produce the derivative-CPE and derivative-RSE
respectively.
[0139] For the derivative-CP and derivative-RS, the tetra, penta
etc prefixes only indicate the average degrees of esterification or
etherification. The compounds exist as a mixture of materials
ranging from the monoester to the fully esterified ester. It is the
average degree of esterification as determined by weight that is
referred to herein.
[0140] The derivative-CP and derivative-RS used do not have any
substantial crystalline character at 20.degree. C. Instead they are
preferably in a liquid or soft solid state, as hereinbelow defined,
at 20.degree. C.
[0141] The starting cyclic polyol or reduced saccharide material is
esterified or etherified with C.sub.8-C.sub.22 alkyl or alkenyl
chains to the appropriate extent of esterication or etherification
so that the derivatives are in the requisite liquid or soft solid
state. These chains may contain unsaturation, branching or mixed
chain lengths.
[0142] Typically the derivative-CP and derivative-RS has 3 or more,
preferably 4 or more, for example 3 to 8, eg 3 to 5, ester or ether
groups or mixtures thereof. It is preferred if two or more of the
ester or ether groups of the derivative-CP and derivative-RS are
independently of one another attached to a C.sub.8 to C.sub.22
alkyl or alkenyl chain. The alkyl or alkenyl groups may be branched
or linear carbon chains.
[0143] The derivative-CPs are preferred for use as the oily sugar
derivative. Inositol is a preferred cyclic polyol, and Inositol
derivatives are especially preferred.
[0144] In the context of the present invention the terms
derivative-CP and derivative-RS encompass all ether or ester
derivatives of all forms of saccharides which fall into the above
definition, which are especially preferred for use. Examples of
preferred saccharides for the derivative-CP and derivative-RS to be
derived from are monosaccharides and disaccharides.
[0145] Examples of monosaccharides include xylose, arabinose,
galactose, fructose, sorbose and glucose. Glucose is especially
preferred. An example of a reduced saccharide is sorbitan. Examples
of disaccharides include maltose, lactose, cellobiose and sucrose.
Sucrose is especially preferred.
[0146] If the derivative-CP is based on a disaccharide it is
preferred if the disaccharide has 3 or more ester or ether groups
attached to it. Examples include sucrose tri, tetra and penta
esters.
[0147] Where the cyclic polyol is a reducing sugar it is
advantageous if each ring of the derivative-CP has one ether group,
preferably at the C.sub.1 position. Suitable examples of such
compounds include methyl glucose derivatives.
[0148] Examples of suitable derivative-CPs include esters of
alkyl(poly)glucosides, in particular alkyl glucoside esters having
a degree of polymerisation from 1 to 2.
[0149] The HLB of the derivative-CP and derivative-RS is typically
between 1 and 3.
[0150] The derivative-CP and derivative-RS may have branched or
linear alkyl or alkenyl chains (of varying degrees of branching),
mixed chain lengths and/or unsaturation. Those having unsaturated
and/or mixed alkyl chain lengths are preferred.
[0151] One or more of the alkyl or alkenyl chains (independently
attached to the ester or ether groups) may contain at least one
unsaturated bond.
[0152] For example, predominantly unsaturated fatty chains may be
attached to the ester/ether groups, e.g. those attached may be
derived from natural oils such as rapeseed oil, cotton seed oil and
soybean oil; or natural fatty acids such as , oleic acid, tallow
fatty acid, palmitoleic acid, linoleic acid, erucic acid or other
sources of unsaturated vegetable fatty acids.
[0153] The alkyl or alkenyl chains of the derivative-CP and
derivative-RS are preferably predominantly unsaturated, for example
sucrose tetratallowate, sucrose tetrarapeate, sucrose tetraoleate,
sucrose tetraesters of soybean oil or cotton seed oil, cellobiose
tetraoleate, sucrose trioleate, sucrose triapeate, sucrose
pentaoleate, sucrose pentarapeate, sucrose hexaoleate, sucrose
hexarapeate, sucrose triesters, pentaesters and hexaesters of
soybean oil or cotton seed oil, glucose trioleate, glucose
tetraoleate, xylose trioleate, or sucrose tetra-,tri-, penta- or
hexa-esters with any mixture of predominantly unsaturated fatty
acid chains.
[0154] However some derivative-CPs and derivative-RSs can be based
on polyunsaturated fatty acid derived alkyl or alkenyl chains, e.g.
sucrose tetralinoleate. However, it is preferred that most, if not
all of the polyunsaturation has been removed by partial
hydrogenation if such polyunsaturated fatty acids are used.
[0155] The most highly preferred liquid derivative-CP and
derivative-RS are any of those mentioned in the above three
paragraphs but where the polyunsaturation has been removed through
partial hydrogenation.
[0156] Preferably 40% or more of the chains contain an unsaturated
bond, more preferably 50% or more, most preferably 60% or more e.g.
65% 95% by number of the chains are unsaturated.
[0157] Oily sugar derivatives particularly suitable for use in the
compositions include sucrose pentalaurate, sucrose tetraoleate,
sucrose pentaerucate, sucrose tetraerucate, and sucrose
pentaoleate. Suitable materials include some of the Ryoto series
available from Mitsubishi Kagaku Foods Corporation.
[0158] The liquid or soft solid derivative-CP and derivative-RS are
characterised as materials having a solid:liquid ratio of between
50:50 and 0:100 at 20.degree. C. as determined by T.sub.2
relaxation time NMR, preferably between 43:57 and 0:100, most
preferably between 40:60 and 0:100, such as, 20:80 and 0:100. The
T.sub.2 NMR relaxation time is commonly used for characterising
solid:liquid ratios in soft solid products such as fats and
margarines. For the purpose of the present invention, any component
of the NMR signal with a T.sub.2 of less than 100 microsecond is
considered to be a solid component and any component with T.sub.2
greater than 100 microseconds is considered to be a liquid
component.
[0159] The liquid or soft solid derivative-CPE and derivative-RSE
can be prepared by a variety of methods well known to those skilled
in the art. These methods include acylation of the cyclic polyol or
of a reduced saccharide with an acid chloride; trans-esterification
of the cyclic polyol or of a reduced saccharide material with short
chain fatty acid esters in the presence of a basic catalyst (e.g.
KOH); acylation of the cyclic polyol or of a reduced saccharide
with an acid anhydride, and, acylation of the cyclic polyol or of a
reduced saccharide with a fatty acid. Typical preparations of these
materials are disclosed in U.S. Pat. No. 4,386,213 and AU 14416/88
(Procter and Gamble).
[0160] The rinse compositions may comprise from 0.5%-90 wt % of the
oily sugar derivatives, more preferably 5-80 wt %, most preferably
10-60 wt %, based on the total weight of the composition.
[0161] Formulation and Dispersion Aids
[0162] Rinse compositions may contain one or more formulation aids
and/or dispersing aids.
[0163] A typical formulation aid is substantially non-aqueous and
comprises one or more of the following components:
[0164] (a) nonionic stabilising agents;
[0165] (b) polymeric compounds having;
[0166] (c) single long hydrocarbyl chain cationic surfactants;
[0167] (d) long chain fatty alcohols or acids;
[0168] (e) short chain alcohols or oils; or
[0169] (f) inorganic and/or organic electrolytes
[0170] Nonionic Stabilising Agents
[0171] The nonionic stabilising agents suitable for use in the
rinse conditioner compositions include any of the alkoxylated
materials of the particular type described hereinafter can be used
as the nonionic surfactant.
[0172] Substantially water soluble surfactants of the general
formula:
R--Y--(C.sub.2H.sub.4O).sub.2 C.sub.2H.sub.4OH
[0173] where R is selected from the group consisting of primary,
secondary and branched chain alkyl and/or acyl hydrocarbyl groups;
primary, secondary and branched chain alkenyl hydrocarbyl groups;
and primary, secondary and branched chain alkenyl-substituted
phenolic hydrocarbyl groups; the hydrocarbyl groups having a chain
length of from 8 to about 25, preferably 10 to 20, e.g. 14 to 18
carbon atoms.
[0174] In the general formula for the ethoxylated nonionic
surfactant, Y is typically:
[0175] --O--, --C(O)O--, --C(O)N(R)-- or --C(O)N(R)R--
[0176] in which R has the meaning given above or can be hydrogen;
and Z is at least about 8, preferably at least about 10 or 11.
[0177] Preferably the nonionic surfactant has an HLB of from about
7 to about 20, more preferably from 10 to 18, e.g. 12 to 16.
[0178] Examples of nonionic surfactants follow. In the examples,
the integer defines the number of ethoxy (EO) groups in the
molecule.
[0179] A. Straight-Chain, Primary Alcohol Alkoxylates
[0180] The deca-, undeca-, dodeca-, tetradeca-, and
pentadecaethoxylates of n-hexadecanol, and n-octadecanol having an
HLB within the range recited herein are useful
viscosity/dispersibility modifiers in the context of this
invention. Exemplary ethoxylated primary alcohols useful herein as
the viscosity/dispersibility modifiers of the compositions are
C.sub.18 EO(10); and C.sub.8 EO(11). The ethoxylates of mixed
natural or synthetic alcohols in the "tallow" chain length range
are also useful herein. Specific examples of such materials include
tallow alcohol-EO(11), tallow alcohol-EO(18), and tallow alcohol-EO
(25).
[0181] B. Straight-Chain, Secondary Alcohol Alkoxylates
[0182] The deca-, undeca-, dodeca-, tetradeca-, pentadeca-,
octadeca-, and nonadeca-ethoxylates of 3-hexadecanol,
2-octadecanol, 4-eicosanol, and 5-eicosanol having an HLB within
the range recited herein are useful viscosity and/or
-dispersibility modifiers in the context of this invention.
Exemplary ethoxylated secondary alcohols useful herein as the
viscosity and/or dispersibility modifiers of the compositions are:
C.sub.16 EO(11); C.sub.20 EO(11); and C.sub.16 EO(14)
[0183] C. Alkyl Phenol Alkoxylates
[0184] As in the case of the alcohol alkoxylates, the hexa- to
octadeca-ethoxylates of alkylated phenols, particularly monohydric
alkylphenols, having an HLB within the range recited herein are
useful as the viscosity and/or dispersibility modifiers of the
instant compositions. The hexa- to octadeca-ethoxylates of
p-tri-decylphenol, m-pentadecylphenol, and the like, are useful
herein. Exemplary ethoxylated alkylphenols useful as the viscosity
and/or dispersibility modifiers of the mixtures herein are:
p-tridecylphenol EO(11) and p-pentadecylphenol EO(18).
[0185] As used herein and as generally recognized in the art, a
phenylene group in the nonionic formula is the equivalent of an
alkylene group containing from 2 to 4 carbon atoms. For present
purposes, nonionics containing a phenylene group are considered to
contain an equivalent number of carbon atoms calculated as the sum
of the carbon atoms in the alkyl group plus about 3.3 carbon atoms
for each phenylene group.
[0186] D. Olefinic Alkoxylates
[0187] The alkenyl alcohols, both primary and secondary, and
alkenyl phenols corresponding to those disclosed immediately
hereinabove can be ethoxylated to an HLB within the range recited
herein and used as the viscosity and/or dispersibility modifiers of
the instant compositions.
[0188] E. Branched Chain Alkoxylates
[0189] Branched chain primary and secondary alcohols which are
available from the well-known "OXO" process can be ethoxylated and
employed as the viscosity and/or dispersibility modifiers of
compositions herein.
[0190] The above ethoxylated nonionic surfactants are useful in the
present compositions alone or in combination, and the term
"nonionic surfactant" encompasses mixed nonionic surface active
agents.
[0191] The nonionic surfactant is present in an amount from 0.01 to
10%, more preferably 0.5 to 5%, most preferably 0.75 to 3.5%, e.g.
1 to 2% by weight, based on the total weight of the
composition.
[0192] Single long hydrocarbyl chain cationic surfactants
[0193] The compositions of the invention optionally contain a
single long hydrocarbyl chain cationic surfactant.
[0194] The single long hydrocarbyl chain cationic surfactant are
particularly suitable for use in emulsions since they can be
employed in the formulation to aid the dispersion characteristics
of the emulsion and/or to emulsify the composition, in order to
form a macroemulsion having oil droplets which are smaller than
those in macroemulsion compositions comprising the cationic fabric
softening agent alone.
[0195] The single long chain cationic surfactant is preferably a
quaternary ammonium compound comprising a hydrocarbyl chain having
8 to 40 carbon atom, more preferably 8 to 30, most preferably 12 to
25 carbon atoms (e.g. quaternary ammonium compounds comprising a
C10-18 hydrocarbyl chain are especially preferred).
[0196] Examples of commercially available single long hydrocarbyl
chain cationic surfactants which may be used in the compositions of
the invention include;
[0197] ETHOQUAD (RTM) 0/12 (oleylbis(2-hydroxyethyl)methylammonium
chloride);
[0198] ETHOQUAD (RTM) C12 (cocobis(2-hydroxyethyl)methyl ammonium
chloride) and
[0199] ETHOQUAD (RTM) C25 (polyoxyethylene(15)cocomethylammonium
chloride), all ex
[0200] Akzo Nobel; SERVAMINE KAC (RTM), (cocotrimethylammonium
methosulphate),
[0201] ex Condea; REWOQUAT (RTM) CPEM,
(coconutalkylpentaethoxymethylammon- ium methosulphate), ex Witco;
cetyltrimethylammonium chloride (25% solution supplied by Aldrich);
RADIAQUAT (RTM) 6460, (coconut oil trimethylammonium chloride), ex
Fina Chemicals; NORAMIUM (RTM) MC50, (oleyltrimethylammonium
chloride), ex Elf Atochem.
[0202] The single long hydrocarbyl chain cationic surfactant is
preferably present in an amount from 0 to 5% by weight, more
preferably 0.01 to 3% by weight, most preferably 0.5 to 2.5% by
weight, based on the total weight of the composition.
[0203] Long Chain Fatty Alcohols, Acids or Oils:
[0204] The formulation aid may further be selected from fatty
alcohols, acids or oils, for example C8 to C24 alkyl or alkenyl
monocarboxylic acids, alcohols or polymers thereof and C.sub.8 to
C.sub.35 oils. Preferably saturated fatty acids or alcohols are
used, in particular, hardened tallow C.sub.16 to C.sub.18 fatty
acids.
[0205] Preferably the fatty acid is non-saponified, more preferably
the fatty acid is free, for example oleic acid, lauric acid or
tallow fatty acid. The level of fatty acid material is preferably
more than 0.1% by weight, more preferably more than 0.2% by weight.
Concentrated and superconcentrated compositions may comprise from
0.5 to 20% by weight of fatty acid, more preferably 1% to 10% by
weight.
[0206] Suitable fatty acids include stearic acid (PRIFAC 2980),
myristic acid (PRIFAC 2940), lauric acid (PRIFAC 2920), palmitic
acid (PRIFAC 2960), erucic acid (PRIFAC 2990), sunflower fatty acid
(PRIFAC 7960), tallow acid (PRIFAC 7920), soybean fatty acid
(PRIFAC 7951) all ex Unichema; azelaic acid (EMEROX 1110) ex
Henkel.
[0207] The fatty acid may also act as a co-softener in the rinse
conditioner composition.
[0208] The formulation aid may comprise a long chain oil. The oil
may be a mineral oil, an ester oil, a silicone oil and/or natural
oils such as vegetable or essential oils. However, ester oils or
mineral oils are preferred.
[0209] The ester oils are preferably hydrophobic in nature. They
include fatty esters of mono or polyhydric alcohols having from 1
to 24 carbon atoms in the hydrocarbon chain, and mono or
polycarboxylic acids having from 1 to 24 carbon atoms in the
hydrocarbon chain, provided that the total number of carbon atoms
in the ester oil is equal to or greater than 8., and that at least
one of the hydrocarbon chains has 12 or more carbon atoms.
[0210] Suitable ester oils include saturated ester oils, such as
the PRIOLUBES (ex. Unichema). 2-ethyl hexyl stearate (PRIOLUBE
1545), neopentyl glycol monomerate (PRIOLUBE 2045) and methyl
laurate (PRIOLUBE 1415) are particularly preferred although oleic
monoglyceride (PRIOLUBE 1407) and neopentyl glycol dioleate
(PRIOLUBE 1446) are also suitable.
[0211] It is preferred that the viscosity of the ester oil is from
0.002 to 0.4 Pa.S (2 to 400 cps) at a temperature of 25.degree. C.
at 106s.sup.-1, measured using a Haake rotoviscometer NV1, and that
the density of the mineral oil is from 0.8 to 0.9 g.cm.sup.-3 at
25.degree. C.
[0212] Suitable mineral oils include branched or straight chain
hydrocarbons (e.g. paraffins) having 8 to 35, more preferably 9 to
20 carbon atoms in the hydrocarbon chain.
[0213] Preferred mineral oils include the Marcol technical range of
oils (ex Esso) although particularly preferred is the Sirius range
(ex Silkolene) or Semtol (ex. Witco Corp.). The molecular weight of
the mineral oil is typically within the range 100 to 400.
[0214] One or more oils of any of the above mentioned types may be
used.
[0215] It is believed that the oil provides excellent perfume
delivery to the cloth and also increases perfume longevity upon
storage of the composition.
[0216] The oil may be present in an amount from 0.1 to 40% by
weight, more preferably 0.2-20%, by weight, most preferably 0.5-15%
by weight based on the total weight of the composition.
[0217] Short Chain Alcohols
[0218] The formulation aid may comprise a short chain alcohol.
Preferred are low molecular weight alcohols having a molecular
weight of preferably 180 or less. The alcohol may be mono or
polyhydric.
[0219] The presence of the lower molecular weight alcohol helps
improve physical stability upon storage by lowering the viscosity
to a more desired level and also assists the formation of the
micro-emulsion. Examples of suitable alcohols include ethanol,
isopropanol, n-propanol, dipropylene glycol, t-butyl alcohol,
hexylene glycol, and glycerol.
[0220] The alcohol is preferably present in an amount from 0.1% to
40% by weight, more preferably from 0.2% to 35%, most preferably
0.5 to 20% by weight based on the total weight of the
composition.
[0221] Inorganic and/or organic electrolytes
[0222] The fabric softening composition optionally comprises an
electrolyte.
[0223] The electrolyte may be an inorganic or organic
electrolyte.
[0224] Preferably the electrolyte is present in an amount from
0.001 to 1.5%, more preferably 0.01 to 1%, most preferably 0.02 to
0.7% by weight based on the total weight of the composition.
[0225] Suitable inorganic electrolytes include sodium sulphate,
sodium chloride, calcium(II) chloride, magnesium(II) chloride,
potassium sulphate and potassium chloride.
[0226] The electrolyte improves viscosity control (especially
viscosity reduction) of the compositions and assists dispersion of
the composition.
[0227] Anti-Oxidation/Reduction Stabilisers
[0228] Rinse compositions of the invention may, optionally, also
comprise one or more additional stabilisers which stabilise against
oxidation and/or reduction.
[0229] If the stabilisers are present as anti-oxidants, they may be
added at a level of from 0.005 to 2% by weight based on the total
weight of the composition, more preferably from 0.01 to 0.2% by
weight, most preferably from 0.035% to 0.1% by weight.
[0230] If present as an anti-reduction agent, then the stabiliser
is preferably used in an amount from 0.001% to 0.2% by weight based
on the total weight of the composition.
[0231] The stabilisers assist by assuring good odour stability upon
storage particularly when the composition is prepared using a
surfactant having substantial unsaturated character (i.e. type (a)
surfactants as herein defined).
[0232] Typically, such additional stabilisers include mixtures of
ascorbic acid, ascorbic palmitate and propyl gallate (under the
tradenames Tenox.RTM. PG and Tenox.RTM. S-1); mixtures of butylated
hydroxytoluene, butylated hydroxyanisole, propyl gallate and citric
acid (under the tradename Tenox.RTM. 6); tertiary butylhydroquinone
(under the tradename Tenox.RTM. TBHQ); natural tocopherols (under
the tradenames Tenox.RTM. GT-1 and GT-2); long chain esters of
gallic acid (under the tradenames Irganox.RTM. 1010, Irganox.RTM.
1035, Irganox.RTM. B 117 and Irganox.RTM. 1425) and mixtures
thereof. Tenox products are supplied by Eastman Chemical Products
Inc. Irganox products are supplied by Eastman Chemical Products
Inc. The above stabilisers can also be mixed with chelating agents
such as citric acid; 1-hydroxyethylidene-1,1-diphosphonic acid
(Dequest.RTM. 2010, ex Monsanto); 4,5-dihydroxy-m-benzene-sulphonic
acid/sodium salt (under the tradename Tiron.RTM., ex Kodak) and
diethylenetriaminepentaacetic acid (under the tradename DTPA.RTM.,
ex Aldrich).
[0233] Co-Active Softening Surfactants
[0234] Co-active softening surfactants for cationic surfactants may
also be incorporated in an amount from 0.01 to 20% by weight, more
preferably 0.05 to 10%, based on the total weight of the
composition. Preferred co-active softening surfactants are fatty
amines and fatty N-oxides.
[0235] b) Cellulases
[0236] Cellulase British Patent Specification GB 1 368 599
(Unilever) discloses the use of cellulolytic enzymes, i.e.
cellulases, as harshness reducing agents. It is thought that
cellulase achieves its anti-harshening effect on, e.g. cotton, by
cleaving the cellulosic fibrils which form on the cotton fibres
during the normal washing process.
[0237] This cleavage prevents the fibrils from bonding together and
thereby introducing a degree of rigidity into the fabric.
[0238] It is preferred to use cellulases which have an optimum
activity at alkaline pH values, such as those described in British
Patent Specifications GB 2 075 028 A (Novo Industries A/S), GB 2
095 275 A (Kao Soap Cc Ltd) and 2 094 826 A (Kao Soap Co ltd).
[0239] Examples of such alkaline cellulases are cellulases produced
by a strain of Humicola insolens (Humicola grisea var. the-rmoidea)
particularly the Humicola strain DSM 1800, cellulases produced by a
fungus of Bacillus N or a cellulase 212-producing fungus belonging
to the genus Aeromonas, and cellulase extracted from the
hepatopancreas of a marine mollusc (Dolabella Auricula
Solander).
[0240] The amount of cellulase in a tablet of the invention will,
in general, be from 0.1 to 10% by weight. In terms of cellulase
activity the use of cellulase in an amount corresponding to from
0.25 to 150 or higher regular CX units/gram of the detergent
composition.
[0241] c) Clays
[0242] Certain clays with ion exchange properties are effective as
fabric softeners. It is believed that clay materials achieve their
softening benefit, on e.g. cotton, by coating the cotton fibrils
with a layer of lubricating material. This coating lowers the
friction between the fibrils and reduced their tendency to bond
together.
[0243] Suitable clay materials are phyllosilicate clays with a 2:1
layer structure, which definition includes smectite clays such a
pyrophyllite, montmorillonite, hectorite, saponite and vermiculite,
and includes micas. Particularly suitable clay materials are the
smectite clays described in United States patent specification U.S.
Pat. No. 4,062,647 (Storm et al assigned to the Procter &
Gamble Company). Other disclosures of suitable clay materials for
fabric softening purposes include European patent specification EP
26528-a (Procter & Gamble Limited). United States Patent
Specification U.S. Pat. No. 3,959,155 (Montgomery et al assigned to
The Procter & Gamble Company) and United States Patent
Specification U.S. Pat. No. 3,936,537).
[0244] EP 177 165 discloses that clays can be used in combination
with cellulase. Also suitable for use in the tablets of the present
invention are the combinations of clays and tertiary amines which
are disclosed in EP 011340 (The Procter & Gamble Company).
[0245] Particularly preferred clays have an ion exchange capacity
of at least 50 meq/100 g of clay. The ion exchange capacity relates
to the expandable properties of the clay and to the charge of the
clay, and is conventionally measured by electrodialysis or by
exchange with ammonium ion followed by titration.
[0246] d) Polysiloxanes and Their Derivatives
[0247] Silicone oils (polysiloxanes) have been proposed as fabric
conditioning agents, and more specifically polysiloxanes with amino
alkyl side chains have been proposed. Discussions of these
materials can be found in GB-A-1549180 where they are included in
fabric softener formulations to assist ironing of the fabric and to
inhibit wrinkling.
[0248] EP-A-150867 discloses the incorporation of amino alkyl
polysiloxanes into particulate detergent compositions to enhance
the softeners and handling of washed fabrics. Their use in
particulate compositions is also disclosed in FR-A-2713237 which
utilises them as fabric softeners.
[0249] These materials may be mixed into nonionic detergent before
that is incorporated into a particulate composition, as taught by
EP-A-150867, or absorbed directly into a particulate carrier, as
taught by FR-A-271237, and mixed with the remainder of a
particulate composition. The particulate composition can thereafter
be compacted to form a zone of a tablet in accordance with the
present invention. The amino alkyl polysiloxanes function as fibre
lubricants. They are desirably incorporated into the more rapidly
disintegrating first zone)s) of a tablet of this invention, so as
to deposit on fabric at an early stage of the washing cycle.
[0250] Another fabric conditioning agent which may be utilised is a
curable amine functional silicone (amino alkyl polysiloxane)
disclosed in U.S. Pat. No. 4,911,852 (Procter Gamble) as an
anti-wrinkle agent.
[0251] Wash Compositions
[0252] Wash compositions contain one or more components useful for
the washing of textile fabrics, for example, surfactants,
detergency builders, bleaches, enzymes and other minor
ingredients.
[0253] a) Surfactants
[0254] Compositions according to the invention comprises one or
more surfactants at least one of which is a branched anionic
surfactant suitable for use in laundry wash products.
[0255] Suitable amendments may be chosen from one or more of
anionic, cationic, nonionic amphoteric and zwitterionic
surface-active compounds and mixtures thereof. Many suitable
surface-active compounds are available and are fully described in
the literature, for example, in "Surface-Active Agents and
Detergents", Volumes I and II, by Schwartz, Perry and Berch.
[0256] The total level of all surfactant(s) in the composition as a
whole may for example be from 0.1% to 70% by weight the total
composition but is preferably from 5% to 40%.
[0257] Anionic Surfactants
[0258] Preferably least one of the surfactants in any wash
composition is anionic surfactant.
[0259] As all or part (e.g at least 50%, 60%, 70%, 80%, 90% or 95%
by weight) of the total anionic surfactant component, most
preferred are the linear alkylbenzene sulphonate anionic
surfactants having an average alkyl component of
C.sub.8-C.sub.15.
[0260] Yet other suitable branched anionic surfactants include
secondary alkylsulphonates, secondary alcohol sulphates and
secondary alkyl carboxylates.
[0261] Suitable laundry wash compositions may additionally or
alternatively contain one or more other anionic surfactants in
total amounts corresponding to percentages quoted above for
branched anionic surfactants, provided that at least some branched
anionic surfactant is present. Suitable anionic surfactants are
well-known to those skilled in the art. These include primary alkyl
sulphates, particularly C.sub.8-C.sub.15 primary alkyl sulphates;
alkyl ether sulphates; olefin sulphonates; alkyl xylene
sulphonates; dialkyl sulphosuccinates; and fatty acid ester
sulphonates. Sodium salts are generally preferred. Such other
anionic surfactants typically are used at from 5% to 70% by weight
of the total anionic surfactant, preferably from 10% to 30%.
Moreover, they typically represent from 1% to 15% by weight of the
total composition.
[0262] Nonionic Surfactants
[0263] Wash compositions preferably also contain nonionic
surfactant. Nonionic surfactants that may be used include fatty
acid methyl ester ethoxylates (FAMEE's), e.g. as supplied by Lion
Corp., Henkel KGA, Condea or Clairant, the primary and secondary
alcohol ethoxylates, especially the C.sub.8-C.sub.20 aliphatic
alcohols ethoxylated with an average of from 1 to 20 moles of
ethylene oxide per mole of alcohol, and more especially the
C.sub.10-C.sub.15 primary and secondary aliphatic alcohols
ethoxylated with an average of from 1 to 10 moles of ethylene oxide
per mole of alcohol. Non-ethoxylated nonionic surfactants include
alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides
(glucamide).
[0264] It is preferred if the level of total non-ionic surfactant
is from 0 wt % to 30 wt %, preferably from 1 wt % to 25 wt %, most
preferably from 2 wt % to 15 wt % by weight of the total wash
composition.
[0265] Other Surfactants
[0266] Another class of suitable surfactants comprises certain
mono-long chain-alkyl cationic surfactants for use in main-wash
laundry compositions according to the invention. Cationic
surfactants of this type include quaternary ammonium salts of the
general formula R.sub.1R.sub.2R.sub.3R.sub.4N' X.sup.-- wherein the
R groups are long or short hydrocarbon chains, typically alkyl,
hydroxyalkyl or ethoxylated alkyl groups, and X is a counter-ion
(for example, compounds in which R.sub.1 is a C.sub.8-C.sub.22
alkyl group, preferably a C.sub.8-C.sub.10 or C.sub.12-C.sub.14
alkyl group, R.sub.2 is a methyl group, and R.sub.3 and R.sub.4,
which may be the same or different, are methyl or hydroxyethyl
groups); and cationic esters (for example, choline esters).
[0267] The choice of surface-active compound (surfactant), and the
amount present in the laundry wash compositions according to the
invention, will depend on the intended use of the detergent
composition. In fabric washing compositions, different surfactant
systems may be chosen, as is well known to the skilled formulator,
for handwashing products and for products intended for use in
different types of washing machine. The total amount of surfactant
present will also depend on the intended end use and may be as high
as 60 wt %, for example, in a composition for washing fabrics by
hand. In compositions for machine washing of fabrics, an amount of
from 5 to 40 wt % is generally appropriate. Typically the
compositions will comprise at least 2 wt % surfactant e.g. 2-60%,
preferably 15-40% most preferably 25-35%.
[0268] Surfactant Blends
[0269] Preferred blends comprise the anionic surfactant(s) and one
or more nononic surfactants. Compositions suitable for use in most
automatic fabric washing machines will generally contain anionic
non-soap surfactant, or non-ionic surfactant, or combinations of
the two in any suitable ratio, optionally together with soap.
Typical blends contain total anionic to total nonionic surfactant
in a weight ratio of from 5:1 to 1:1, preferably from 4:1 to
2:1.
[0270] It is also generally preferred that the weight ratio of
total anionic surfactant to total builder is from 1:5 to 10:1, more
preferably from 2:1 to 10:1, especially from 3:1 to 7:1.
[0271] b) Detergency Builders
[0272] Laundry wash compositions, will generally also contain one
or more detergency builders. The total amount of detergency builder
in the compositions will typically range from 5 to 80 wt %,
preferably from 10 to 60 wt % by weight of the total
composition.
[0273] Inorganic builders that may be present include sodium
carbonate, if desired in combination with a crystallisation seed
for calcium carbonate, as disclosed in GB-A-1 437 950; crystalline
and amorphous aluminosilicates, for example, zeolites as disclosed
in GB-A-1 473 201, amorphous aluminosilicates as disclosed in
GB-A-1 473 202 and mixed crystalline/amorphous aluminosilicates as
disclosed in GB-A-1 470 250; and layered silicates as disclosed in
EP-A-164 514. Inorganic phosphate builders, for example, sodium
orthophosphate, pyrophosphate and tripolyphosphate are also
suitable for use with this invention.
[0274] The compositions of the invention preferably contain an
alkali metal, preferably sodium, aluminosilicate builder. Sodium
aluminosilicates may generally be incorporated in amounts of from
10 to 70% by weight (anhydrous basis), preferably from 25 to 50 wt
%.
[0275] When the aluminosilicate is zeolite, the maximum amount is
19% by weight.
[0276] The alkali metal aluminosilicate may be either crystalline
or amorphous or mixtures thereof, having the general formula:
0.8-1.5 Na.sub.2O. Al.sub.2O.sub.3. 0.8-6 SiO.sub.2.
[0277] These materials contain some bound water and are required to
have a calcium ion exchange capacity of at least 50 mg CaO/g. The
preferred sodium aluminosilicates contain 1.5-3.5 SiO.sub.2 units
(in the formula above). Both the amorphous and the crystalline
materials can be prepared readily by reaction between sodium
silicate and sodium aluminate, as amply described in the
literature. Suitable crystalline sodium aluminosilicate
ion-exchange detergency builders are described, for example, in GB
1 429 143 (Procter & Gamble). The preferred sodium
aluminosilicates of this type are the well-known commercially
available zeolites A and X, and mixtures thereof.
[0278] The zeolite may be the commercially available zeolite 4A now
widely used in laundry detergent powders. However, according to a
preferred embodiment of the invention, the zeolite builder
incorporated in the compositions of the invention is maximum
aluminium zeolite P (zeolite MAP) as described and claimed in
EP-A-384 070. Zeolite MAP is defined as an alkali metal
aluminosilicate of the zeolite P type having a silicon to aluminium
ratio not exceeding 1.33, preferably within the range of from 0.90
to 1.33, and more preferably within the range of from 0.90 to
1.20.
[0279] Especially preferred is zeolite MAP having a silicon to
aluminium ratio not exceeding 1.07, more preferably about 1.00. The
calcium binding capacity of zeolite MAP is generally at least 150
mg CaO per g of anhydrous material.
[0280] Organic builders that may be present include polycarboxylate
polymers such as polyacrylates, acrylic/maleic copolymers, and
acrylic phosphinates; monomeric polycarboxylates such as citrates,
gluconates, oxydisuccinates, glycerol mono-, di- and trisuccinates,
carboxymethyloxy succinates, carboxymethyloxymalonates,
dipicolinates, hydroxyethyliminodiacetates, alkyl- and
alkenylmalonates and succinates; and sulphonated fatty acid salts.
This list is not intended to be exhaustive.
[0281] Especially preferred organic builders are citrates, suitably
used in amounts of from 5 to 30 wt %, preferably from 10 to 25 wt
%; and acrylic polymers, more especially acrylic/maleic copolymers,
suitably used in amounts of from 0.5 to 15 wt %, preferably from 1
to 10 wt %.
[0282] Builders, both inorganic and organic, are preferably present
in alkali metal salt, especially sodium salt, form.
[0283] c) Bleaches
[0284] Laundry wash compositions may also suitably contain a bleach
system. Fabric washing compositions may desirably contain peroxy
bleach compounds, for example, inorganic persalts or organic
peroxyacids, capable of yielding hydrogen peroxide in aqueous
solution.
[0285] Suitable peroxy bleach compounds include organic peroxides
such as urea peroxide, and inorganic persalts such as the alkali
metal perborates, percarbonates, perphosphates, persilicates and
persulphates. Preferred inorganic persalts are sodium perborate
monohydrate and tetrahydrate, and sodium percarbonate.
[0286] Especially preferred is sodium percarbonate having a
protective coating against destabilisation by moisture. Sodium
percarbonate having a protective coating comprising sodium
metaborate and sodium silicate is disclosed in GB-A-2 123 044.
[0287] The peroxy bleach compound is suitably present in an amount
of from 0.1 to 35 wt %, preferably from 0.5 to 25 wt %. The peroxy
bleach compound may be used in conjunction with a bleach activator
(bleach precursor) to improve bleaching action at low wash
temperatures. The bleach precursor is suitably present in an amount
of from 0.1 to 8 wt %, preferably from 0.5 to 5 wt %.
[0288] Preferred bleach precursors are peroxycarboxylic acid
precursors, more especially peracetic acid precursors and
pernoanoic acid precursors. Especially preferred bleach precursors
suitable for use in the present invention are N,N,N',N',-tetracetyl
ethylenediamine (TAED) and sodium noanoyloxybenzene sulphonate
(SNOBS). The novel quaternary ammonium and phosphonium bleach
precursors disclosed in U.S. Pat. No. 4,751,015 and U.S. Pat. No.
4,818,426 and EP-A-402 971, and the cationic bleach precursors
disclosed in EP-A-284 292 and EP-A-303 520 are also of
interest.
[0289] The bleach system can be either supplemented with or
replaced by a peroxyacid. examples of such peracids can be found in
U.S. Pat. No. 4,686,063 and U.S. Pat. No. 5,397,501. A preferred
example is the imido peroxycarboxylic class of peracids described
in EP-A-325 288, EP-A-349 940, DE-A-382 3172 and EP-A-325 289. A
particularly preferred example is phtalimido peroxy caproic acid
(PAP). Such peracids are suitably present at 0.1-12%, preferably
0.5-10%.
[0290] A bleach stabiliser (transition metal sequestrant) may also
be present. Suitable bleach stabilisers include ethylenediamine
tetra-acetate (EDTA), the polyphosphonates such as Dequest (Trade
Mark) and non-phosphate stabilisers such as EDDS (ethylene diamine
di-succinic acid). These bleach stabilisers are also useful for
stain removal especially in products containing low levels of
bleaching species or no bleaching species.
[0291] An especially preferred bleach system comprises a peroxy
bleach compound (preferably sodium percarbonate optionally together
with a bleach activator), and a transition metal bleach catalyst as
described and claimed in EP-A-458 397, EP-A-458 398 and EP-A-509
787.
[0292] d) Enzymes
[0293] Laundry wash compositions according to the invention may
also contain one or more enzyme(s). Suitable enzymes include the
proteases, amylases, cellulases, oxidases, peroxidases and lipases
usable for incorporation in detergent compositions. Preferred
proteolytic enzymes (proteases) are, catalytically active protein
materials which degrade or alter protein types of stains when
present as in fabric stains in a hydrolysis reaction. They may be
of any suitable origin, such as vegetable, animal, bacterial or
yeast origin.
[0294] Proteolytic enzymes or proteases of various qualities and
origins and having activity in various pH ranges of from 4-12 are
available and can be used in the instant invention. Examples of
suitable proteolytic enzymes are the subtilisins which are obtained
from particular strains of B. Subtilis B. licheniformis, such as
the commercially available subtilisins Maxatase (Trade Mark), as
supplied by Gist Brocades N. V., Delft, Holland, and Alcalase
(Trade Mark), as supplied by Novo Industri A/S, Copenhagen,
Denmark.
[0295] Particularly suitable is a protease obtained from a strain
of Bacillus having maximum activity throughout the pH range of
8-12, being commercially available, e.g. from Novo Industri A/S
under the registered trade-names Esperase (Trade Mark) and Savinase
(Trade-Mark). The preparation of these and analogous enzymes is
described in GB 1 243 785. Other commercial proteases are Kazusase
(Trade Mark obtainable from Showa-Denko of Japan), Optimase (Trade
Mark from Miles Kali-Chemie, Hannover, West Germany), and Superase
(Trade Mark obtainable from Pfizer of U.S.A.).
[0296] Detergency enzymes are commonly employed in granular form in
amounts of from about 0.1 to about 3.0 wt %. However, any suitable
physical form of enzyme may be used.
[0297] e) Other Optional Minor Ingredients
[0298] Laundry wash compositions may contain alkali metal,
preferably sodium carbonate, in order to increase detergency and
ease processing. Sodium carbonate may suitably be present in
amounts ranging from 1 to 60 wt %, preferably from 2 to 40 wt %.
However, compositions containing little or no sodium carbonate are
also within the scope of the invention.
[0299] Yet other materials that may be present in detergent
compositions of the invention include sodium silicate;
antiredeposition agents such as cellulosic polymers; inorganic
salts such as sodium sulphate; lather control agents or lather
boosters as appropriate; dyes; coloured speckles; perfumes; foam
controllers; fluorescers and decoupling polymers. This list is not
intended to be exhaustive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0300] FIG. 1 shows a tablet for use in a first embodiment of the
present invention;
[0301] FIG. 2 shows a water soluble sachet for use in a second
embodiment of the present invention;
[0302] FIG. 3 shows a bag net receptacle for use in the first and
second embodiments of the present invention;
[0303] FIG. 4 shows another tablet for use in a third embodiment of
the present invention, in conjunction with the bag net receptacle
of FIG. 3;
[0304] FIG. 5 shows a capsule for use in the fourth embodiment of
the present invention;
[0305] FIGS. 6A-6C show layered tablet embodiments;
[0306] FIG. 7 shows a sachet in tablet embodiment; and
[0307] FIGS. 8A-8C show embodiments wherein the delayed release
rinse composition is embedded in the tablet.
EXAMPLES AND DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0308] In the following examples, various embodiments of unit dose
compositions are disclosed which in use, are dosed in the net
described hereinbelow with respect to FIG. 3.
EXAMPLE 1
Polymer Matrix in Tablet
[0309] FIG. 1 shows a unit dose unit 1 for use according to the
present invention. It comprises a tablet 3 of a granular detergent
wash composition 5, having a composition in the range of
formulation A. In all formulations herein, percentages are by
weight unless specified to the contrary.
1 Formulation A NaLAS 8.0-11.0% Nonionic 7EO 4.0-5.0% Soap 0.5-1.0%
Zeolite A24 (anhydrous) 20-25.0% Sodium acetate 20-25% Soda ash
3.0-4.0% SCMC 0.3-0.4% Minors etc. 4.00% Antifoam 1.5-2.5%
Fluorescer (10% ac.) 1.0-2.0% Soil release polymer 0.3-0.5%
Na-di-silicate (granular) 2.0-3.0% TAED 4.0-5.0% Percarbonate
(coated) 10.0-15.0% Sequestrant 1-15% Proteolytic and Lypolytic
enzymes .sup. <1% Perfume 0.5%
[0310] Na LAS--Sodium Docecyl Benzene Sulphonate
[0311] Nonionic 7EO --C.sub.9-C.sub.11 alkohol ethoxylated with an
average of seven ethylene oxide units
[0312] SCMC--Sodium carboxy methyl cellulose
[0313] The tablet is formed by compression of the granular
ingredient 5 but in a die such as to be formed with a central
cavity 7.
[0314] The central cavity 7 is formed with a polymer 9 having the
following composition:
Polymer (1)
[0315] Polymer (1) is a pH-sensitive polyacrylate-terpolymer,
synthesized from a blend of the following weight composition 23%
MMA (methylmethylacrylate), 45% DMAEMA (N,N-dimethylamino ethyl
methacrylate) and 32% DMAPMA (dimethylaminopropylmethacrylic acid
amine)
[0316] A granular fabric softening composition 11 (Formation B) is,
together with a dissolution aid like Na-acetate or Na-citrate,
dispersed in the polymer composition 9. The fabric softener is
mixed with the polymer and poured into the cavity 7, whereupon it
sets to form a solid matrix of the composition 11 and solidified
polymer 9.
Polymer (2)
[0317] Polymer (2) is an hydroxybutylmethyl cellulose (hydroxybutyl
content of 3.5 mole %) having a number average molecular weight of
ca. 115,000 g/mole.
[0318] The granular fabric softening composition 11 has the
following formulation B:
2 Formulation B HEQ 34.5% Urea 41.48% Dobanol 91/6 6.14% Water
5.77% Perfume 2.88% PEG 1.95 Dye 0.28 Microsil GP 7.00%
[0319] HEQ is a hardened tallowyl fatty acid quaternary fabric
softener, ex Clairant
[0320] Dobanol 91/6 is a C.sub.9-11 average 6EO nonionic surfactant
ex Shell
[0321] PEG 1500 is polyethylene glycol MW=1500.
[0322] Microsil GP is a commercially available silica based flow
aid.
[0323] Polymer (1) is such that it is substantially insoluble at
the pH and ionic strength of the wash liquor (the granular wash
composition 5 dissolves quite rapidly, at least sufficiently to
achieve these conditions). However, the Polymer 1 is readily
soluble at the pH and ionic strength of the rinse liquor).
[0324] A variant of this example, wherein the polymer is in the
form of a melt, is described hereinbelow in Example 3.
EXAMPLE 2
Dual Sachet
[0325] FIG. 2 shows a water soluble sachet embodiment 21. This
comprises an outer sachet 23, formed from a polyvinyl alcohol film
by the VFSS technique. The film is Monosol. T, ex Chris-Craft
Industrial Products Inc., with polyhydroxy plasticisers. Located
inside outer sachet 23 is an inner sachet 25, of smaller dimensions
than the outer sachet 23, formed also by the VFSS technique made
from Polymer (1). This means that it will not dissolve at the wash
liquor pH but only at the rinse liquor pH, unlike the polymer of
the outer sachet.
[0326] The top edge 31 and bottom edge 33 of the inner sachet 25
are sealed by conventional heat or ultrasonic sealing common in
VFSS polymer sachet manufacture. Prior to final sealing, the inner
sachet 25 is filled with the granular fabric softener composition
of Formulation B recited above.
[0327] The space between the inner sachet 25 and the film of the
outer sachet 23 is filled with the granular detergent wash
composition of Formulation A defined in Example 1.
[0328] The top edge 35 and the bottom edge 37 of the outer sachet
23 are also seated by heat or ultrasonic method.
[0329] In a variant of the embodiment of FIG. 2, instead of a
granular detergent wash composition 30 in the outer sachet, there
is located a substantially non-aqueous liquid laundry cleaning
composition having the following composition:
3 Formulation C Nonionic (Neodol C11. 26% 5EO) LAS acid 20%
Priolene 6907 fatty acid 13% Glycerol 20% Perfume 1% Enzymes +
polymer 2% Monopropylene glycol 7% Monoethanolamine 9% Water
balance
[0330] In the inner sachet 25, is located a substantially
non-aqueous liquid fabric softening composition having the
following formulation D:
4 Formulation D AOT-1 19.6% Nonionic 5EO 35.6% Estol 1545 38.4%
Dipropylene Glycol 4.9% Perfume 1.5%
[0331] AOT-1 is a commercially available unsaturated triester amine
quaternary ammonium fabric softener.
[0332] Nonionic SEO is a C.sub.9-C.sub.11 alcohol ethoxylated with
an average of 5 ethylene oxide units.
[0333] Estol 1545 is a commercially available ester mineral
oil.
[0334] The inner sachet is formed of polymer (2). In this case, the
inner sachet will not dissolve at a wash liquor temperature of
40.degree. C. or higher but only at a rinse liquor temperature
below 40.degree. C.
[0335] FIG. 3 shows a net bag 41 for use with either the tablet 1
of FIG. 1 or the sachet 21 of FIG. 2, as well as other examples and
embodiments described hereinbelow. It has an average mesh size of 5
mm. It comprises a substantially elongate bag member 43 of nylon
mesh, open at a mouth 45. The mouth 45 can be closed at constricted
neck region 51 by means of a drawstring 47. A plastics constriction
member 49 can be slid along the drawstring 47 to keep the
restricted neck region 51 closed.
[0336] In use, either the tablet 1 or sachet 21, is placed in the
bag 41 and the bag is closed by use of the constriction member 49
with the drawstring 47 as indicated above.
[0337] The net with sachet or tablet inside, is then placed in an
automatic washing machine, directly into the drum. The fabrics to
be cleaned are also loaded into the drum.
[0338] In the case of the tablet of FIG. 1, in the wash cycle, the
detergent wash composition 5 is released into the wash liquor to
clean the fabric. However, the pH of the wash liquor is around 10.5
and the conductivity is 4.5 mS/cm which is too alkaline and too
high an ionic strength for the polymer matrix 9 to substantially
dissolve. However, after the rinse cycle, the pH of the rinse
liquor is only about 8.5 and the conductivity is 1.1 mS/cm.
[0339] As a result, at this lower pH, the polymer matrix 9
dissolves so as to release the granular rinse condition of
composition 11 into the rinse liquor.
[0340] In the case of the sachet of FIG. 2, the composition of the
film of the outer sachet 23 is such that it dissolves in the wash
liquor, i.e. at the wash liquor pH. However, the composition of the
polymer film of the inner sachet 25 is insoluble at the wash liquor
pH. In a variant, the outer sachet 23 may be formed of a polymer
which dissolves at the wash liquor temperature.
[0341] After the wash cycle, at the lower rinse cycle pH, (or lower
rinse cycle temperature, in the case of the variant). The polymer
of the inner sachet 25 is soluble and so the granular rinse
composition can be released.
EXAMPLE 3
Gel in Tablet
[0342] FIG. 4 shows another tablet emobodiment 61. The tablet
comprises a granular wash composition 63 identical to the
composition of detergent wash composition 5 in FIG. 1 (i.e. having
Formulation A). As with the embodiment of FIG. 1, the tablet also
includes a central cavity 65.
[0343] A granular fabric softening composition 67, identical to
that having Formulation B recited above, is located in the cavity
67, dispersed in a water-soluble polyethylene glycol (PEG). The
composition is mixed with the polymer melt before pouring into the
cavity 67, by making use of the shear thinning behaviour of the gel
of by using a cooling tunnel.
[0344] The upper surface 71 of the set gel matrix 69, including the
softening composition 67, is covered with a polymer film 73 which
extends in contiguous fashion to line the inside of the cavity 65
in the form of a lining 75. The polymer used in to form the lining
75 and film 73 is identical to that of Polymer (1) recited
above.
[0345] In use, the tablet of FIG. 4 dissolves in the wash liquor
but the pH of the wash liquor is such that the "capsule" formed by
the polymer film 73 and lining 75 does not dissolve. It survives
until the rinse cycle, when the lower pH allows it to dissolve and
the contents released. At that point, the gel 69 dissolves or
disperses, releasing the rinse composition 67 into the rinse
liquor.
[0346] It will be appreciated that the "capsule" of polymer is
fragile. Therefore, it is especially advantageous in this
embodiment for the tablet as a whole to be dosed by means of the
net of FIG. 3.
EXAMPLE 4
Rinse Conditioner Capsule
[0347] FIG. 5 shows a capsule 81 according to a fourth embodiment
of the present invention, when used in the net shown in FIG. 3.
[0348] A granule of 1.5 cm diameter is formed by granulating the
composition of Formula B (fabric softening composition) with a
dissolution aid such as sodium citrate or sodium acetate in a fluid
bed granulator, operated such that large agglomerates can form.
This produces a nearly-spherical granule 83. This granule is then
dipped-coated in a melt of Polymer 1 as recited above. In this way,
the granule 83 is coated with a polymer film 85. When dosed in the
bag of FIG. 3 into the wash liquor, it remains intact until the
rinse cycle, whereupon, the lower pH allows the polymer to dissolve
and the granular rinse conditioner to be dispersed into the rinse
liquor. Preferably, a conventional main wash detergent tablet is
also dosed in the same bag at the start of the wash process.
[0349] The filling of the core 83 of capsule 85 in FIG. 5 may also
be a non-aqueous liquid rinse composition.
[0350] The composition can be used in combination with liquid
detergents, powder detergent, conventional main wash tablets, main
wash sachets and the like. Alternatively, it may be glued on top of
the tablet with a cavity such as shown in FIG. 1 or 4, or can be
used as an insert in a larger capsule containing a main wash
composition.
[0351] The embodiments of FIGS. 6-8 (Examples 5-7) are also dosed
in the net of FIG. 3.
EXAMPLES 5A -5D
Multi-Layer Tablets
[0352] Turning now to FIG. 6A, there is shown a tablet form 91
according to the present invention. It comprises a (larger) lower
portion 93 comprising a tableted wash composition corresponding to
composition 5 in the embodiment of FIG. 1. The upper layer 95
comprises the same rinse composition 11 of the embodiment of FIG.
1, in a delayed release matrix as before. The manufacture of
bi-layer tablets is well known in the art.
[0353] In FIG. 6B, a bi-layer tablet 97 has a lower layer 99
corresponding to the lower layer 93 of the embodiment of FIG. 6A.
However, the upper layer 101 comprises a rinse composition 103
corresponding to composition 67 in the embodiment of FIG. 4,
encapsulated in a delayed release polymer shell 105 corresponding
to shell 75 in the embodiment of FIG. 4.
[0354] FIG. 6C shows a variant of the embodiment of FIG. 6A but as
a tri-layer tablet. This designated 107. The upper 109 and lower
111 layers correspond to the tableted wash composition 93 in the
embodiment of FIG. 6A. The middle layer 113 has the same rinse
composition embedded in a delayed release matrix as the layer 95 in
the embodiment of FIG. 6A.
[0355] In the embodiment of FIG. 6D, the trilayer tablet is
analogous to the embodiment of FIG. 6B and is denoted by numeral
115. A central layer 117 has the same rinse composition as
composition 103 in the embodiment of FIG. 6B and is denoted by
numeral 119. It is surrounded by a delayed release polymer shell
121 of the same composition as that of shell 105 in FIG. 6B.
[0356] Thus in general, the softener composition may be
co-granulated in a delayed release polymer melt as referred to in
hereinbefore or coated with a polymer in a bi or tri layer tablet
form.
[0357] In a variant of the embodiment of FIG. 6A, the upper layer
consists of a matrix of capsules, like those of the embodiment of
FIG. 5 (Example 4) except that they are formed with a diameter of
7.5 mm. They are embedded in a soft solid matrix comprising a
surfactant mixture. In a further variation, a dissolution aid is
admixed with this surfactant mixture. In still a further variation,
the capsules are dispersed in polyethylene glycol (MW ca. 4,000).
The latter is water soluble.
EXAMPLE 6
Sachet in Tablet
[0358] Turning now to FIG. 7, there is shown a tablet embodiment
125 containing a tablet form 127 of a wash composition
corresponding to the composition of tablet form 63 in the
embodiment of FIG. 4. It contains a cavity 129 extending into the
centre from the outside thereof, in which is contained a
water-soluble delayed release sachet 131. This is formed of Polymer
(1). It is filled with a liquid or granular rinse composition
133.
EXAMPLES 7A-7C
Tablets with Embedded Rinse Compositions
[0359] Turning now to FIGS. 8A-8C, there are shown various embodied
tablet forms, which may be made by methods known to those skilled
in the art. In all cases, there is a cylindrical tablet 135 of wash
composition in the middle of which is a cavity 137 which does not
connect with the exterior surface of the tablet.
[0360] In the embodiment of FIG. 8A, a central rinse composition is
co-granulated with a delayed release polymer matrix 139 of the same
composition as the layer 95 in the embodiment of FIG. 6A.
[0361] In the embodiment of FIG. 8B, the rinse composition 141 is
coated with delayed release polymer 145 and so the central insert
has the same composition as the upper layer 101 in the embodiment
of FIG. 6B.
[0362] In FIG. 8C, the central cavity contains a delayed release
water-soluble sachet 147 filled with a granular or liquid rinse
composition 149.
EXAMPLE 8
Unit Dose Rinse Conditioner
[0363] Composition and Method of Manufacture:
[0364] A tablet composition was prepared from the following
ingredients
5 Formulation E Bentonite clay 80% Sodium acetate 18% Perfume 2%
Dye 0.03%
[0365] The method of manufacture consisted of mixing all
ingredients in a Fukae high-shear mixer to form a powder. The
powder was then compacted using a Korsch rotative tablet press with
concave shaped upper and lower punch. The weight of the convex
shaped unit dose was 10 grams having a diameter of 25 mm. The unit
dose dispersed in water of 20.degree. C. within 5 minutes. The
tablet was coated with polymer (2) by means of a Glatt GC300 drum
coater. The polymer was applied from an aqueous solution using
glycerol as a plasticizer.
[0366] Method of Dosing the Unit Dose Rinse Additive
[0367] The dispersion of the unit dose rinse additive was evaluated
in a Zanussi FGS 1276 washing machine. Different methods of dosing
the unit dose rinse additive to the washing machine were evaluated:
(a) dosing via the drawer together with two laundry wash tablets of
formulation A above; (b) dosing directly in the drum together with
the two laundry wash tablets; and (c) dosing directly in the drum
using the net of FIG. 3, together with the two laundry wash
tablets.
[0368] By dosing via the drawer the rinse additive tablet could not
be dispensed to the drum as a result of its dimension. Due to
partial dissolution of the tablet coating a lump of residue was
formed, which remained in the drawer for the remainder of the wash
cycle.
[0369] By dosing the rinse additive tablet directly in the drum, it
was observed that, out of ten wash cycles, the tablet became
entrapped in the rubber gasket of the machine three times. This
resulted in significant residue at the end of the wash cycle, which
is not acceptable for the consumer.
[0370] By dosing the rinse additive tablet using the net,
entrapment of the tablet in the rubber gasket was prevented, and
the tablet dispersed properly during the rinse portion of the wash
cycle due to the triggered dissolution of the coating. Only by use
of the net the unit dose rinse additive could be properly delivered
in the rinse liquor.
[0371] Lubrication Benefit
[0372] In a Zanussi FGS 1276 washing machine, 1 kg load comprising
3:3:2:3 flat cotton, knitted cotton, P/C polyester (including 10
poplin monitors (40.times.40 cm)) was washed at 40.degree. C.,
27.degree. F.H, using a normal wash cycle (with a spin speed of
1200 rpm). Two tablets of a composition corresponding to
Formulation A were dosed together with the rinse conditioner tablet
described above. The effect of the dosing method on the lubrication
of poplin swatches after one wash is summarised below. Lubrication
was measured by means of the Kawabata shear methodology.
6 Kawabata shear Method of dosing rinse Triggered release (the
lower the Standard additive coating better) deviation Drawer Yes
8.06 0.14 Drum, No 7.59 0.34 In Net Drum, Outside Net Yes 8.15 0.25
Drum, Yes 7.22 0.15 In Net
[0373] The data show that the highest lubrication benefit is
obtained by dosing the unit dose rinse additive with the polymer
(2) coating in the net.
[0374] In the light of the described embodiments and examples,
variations of those embodiments and examples, as well as other
embodiments and examples, all within the spirit and scope of the
present invention, for example as defined by the appended claims,
will now become apparent to persons skilled in this art.
* * * * *