Note: Descriptions are shown in the official language in which they were submitted.
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- D~ERGE~ PRODUC~S
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- _ C ~ D
~ his invention relates_to detergent products which
are suit~ble for fabric washing and-which contain
de-tergent compositions in particuIate form.
BAGKGROUND AR
Although the marke-ting of parti~ulate detergent
compositions packaged ln cartons is common practice, this
- imposes co~straints both on their formula-tion and methods
of production. ~or example the co~ositions must be ~ree
flowing and have an a-ttractive appearance to the consumer,
and the ingredients should not segregate during transport
and storage. The products must also be sa~e, both for
contact wi-th the skin and in the event of accidental
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inges-tion; in par-ticular, the compositions should not
contain too high a level of alkaline materials, although
~lkalinity is beneficial for detergent properties.
When using ~Jashing machines which have a rotating drum
in which -the fabrics are placed, there can also be
substan-tial losses of conventionally dosed detergent
powder by retention in the dispenser and by its accumulation
in the dead spaces beneath the drum,- such as the drain hose.
It has been proposed previously to market powdered
detergen-t compositions in packages~, each of which contain
suitable amounts of the detergent powders for individual
washes under standard washing conditio~s. In particular,
from ~ritish Patent Specification ~ 98 454 and United
~tates Patent ~pecification 3 198 740 the detergent powders
can be contained within bags of water-permeable or water-
soluble materials, such as soluble polyvinyl alcohol, but
such packages have not yet met with much commercial success~
- One of the reasons for this, in the case of water-soluble
bags, is the sensitivit~ tj mo^isture which leads to storage
difficulties. In the case of water-permeable materials,
one of the reasons is the difficuIty~of making the bags
sufficiently permeable to wa-ter in use so -that the contents
of the bags are rapidly dissolved out in-to the wash liquor,
and yet reducing dusting of the detergent powder out of the
bags during transport and ma~ual handling to an acceptable
level. Also, some detergent compositions, in particular
bleach-containing compositions, cause i~acceptable
degradation of the bag material~
Canadian Patent Specification ~o. 901 24ll discloses a
~0 bag for insecticide powders~ the bag being formed of a
water-soluble film reinforced wi-th a net of water-insoluble
thermoplastic material.
DI~C~OSUPE OF ~HE INVE~IO~
According to the invention there-is provided a detergent
~5 product comprising a particulate de~tergent composition
contained within a closed water-i~soluble~ w~ter-permeable
bag formed of sheet material, a layer of water-soluble or
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removable water-insoluble material protecting -the bag
material from the detergent composition. By using this
-form of construction for the bag, i-t is possible to protect
the 'bag ma*erial during storage and -to prevent undue dusting
of the composition'through the bags and yet the porosity of
the water-insoluble sheet material can be high enough to
quickly release all of -the contents of the bag as soon as
the water-soluble layer is dissolved or the water-insoluble
layer is removed in use. It is possible to use a relatively
open water-insoluble sheet material for the bag, as dusting
of the de-tergent composition through'the pores is reduced
or pre~rented by the water-soluble or removable water-
insoluble layer. Moreover, it is possible -to form the
bags of material which can be readily'heat-sealed, which
facilitates manufactureO
~EST M03E 0_ CA~RYING OUT THE I~VE~TI0~
~ he b~s are formed with a water-insoluble sheet
material which can be formed of paper or of woven, knitted
or non-woven fabric, provided that each of these should be
water-insoluble and water-permeable. If the bags are to
be used for detergent powder which co~tains a bleachlng
agent, for example sodium perborate or sodium percarbonate7
it is also desi'rable to form the bags of sheet material
made from oxidation-resistan-t fibres.
A suitable sheet material for forming -the bag~ is
water-permeable paper or non-woven~'fabric of high we-t
strength, weighing about 5 to 100, preferably 10 to 60 g/m2
- especially about 15 to 40 g/m2, such as is commonly used
for packaging beverage powders and other foodstuffs~ and
sui-table sheet materials of this -ty~e are commerciall~
available for example from J R Crol~pton ~ros Ijtd of Bury~
~ngland ~he fibres preferably usèd for -the sheet
materials may be of na-tural or sy~thetic origin and may be
used alone or in admixture, for example polyamide, poly-
ester, polyacrylic, cellulose acetate, polyethylene, poly-
propylene, PVC, PVdC (polyvin~lidene chloride) or cellulcsic
fibres~ If some cellulose pulp is used, it may be
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desirable to include a proportion of long fibres such as
Manila hemp, in order to improve the s-trength oi the sheet
~material, and pliability, and reducing stiffness, -thereby
giving the ma-terial a fabric-like appearance, and a binder
may be necessary for increasing we-t streng-th. I~ is
preferred to include at least a proportion of thermoplastic~
fibres, for example polypropylene fibres for increasing
resis-tance to chemical attack by any.of the ingredients
of the detergent compositions~
~he lay~r of water-soluble or water-insoluble material
may be either a continuous layer or sheet of such matérial
or a discontinuous layer. Tn the;former case the
continuous layer can be attached, i;e. laminated to the
water-insoluble sheet material, insidë the sheet material
of the bags, or it may be separate ~.rom the sheet material,
so formi ng one bag inside the other. Particularly in the
laminated form.of construction of the.bags using a continuous
layer or sheet of a water-soluble material, i-t is preferred
to use a syn-thetic water-soluble p~lymer (homopolymer or
copolymer) such as soluble polyvi~yl alcohol or ~oly-
ethylene glycol.
Par-ticularly if a water-solubl.e material is applied as
a discontinuous coating on the water-insoluble sheet
material, a wider variety of wa-ter-soluble ma-terials can be
used to give a protective effect7 for example polysaccharides
such as starch or dextrin, alkali metal silicate, soap,
gelatine, salts and esters of alginic acid, salts and
esters of me-thyl cellulose, carbox~methyl cellulose and
water-soluble cationic fabric softeners or water-soluble
synthetic polymers such as wa-ter-soluble polyvinyl alcohol,
polyethylerie glycol or nonionic dc~er~ent compounds.
The water-insoluble sheet material may alternatively
be treated with a removable water-in$oluble protecting
agent. ~his can either be a non-volatile liquid or solid
material,.of organic or inorganic nature, provided that it
is substan-tially inert to the deter~ent system and can be
applied to -the sheet material, be.~ore or af-ter forming the
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bags, to give a protective effect~ The removable water-insoluble
protecting agent should be water dispersible so that, in use, it
is quickiy removed from the bag material, thereby opening up the
pores in the bag material enabling fast dissolution and disper-
sion of the detergent composition in the wash li~uor. In thisspecification the term "removable water-insoluble protecting
agent" is to be construed accordingly. Specific protecting
agents which may be mentioned are waxes which are solid or highly
viscous liquids at room temperature, and which can be applied to
the sheet material to form a protective coating over the fibrous
surface. Such materials are dispersible in detergent wash
liquor, especially at elevated temperatures where they may then
also exert a beneficial lather controlling effect. The waxes
are well known commercially available substances. The waxes can
be of natural or synthetic origin and optionally halogenated to
improve their chemical stability.
Alternative protecting agents are silicones,~fatty acids,
water-insoluble cationic fabric softeners, polymeric materials
such as polyvinylacetate, insoluble polyvinyl alcohol and insol-
uble finely divided inorganic material, such as natural clays orsynthetic colloidal filler substances such as zeolite, calcite,
silica or titania, which can be applied to the sheet material so
as to coat the fibres and to some extent temporarily close the
pores of the sheet material until its addition to water. Pre-
ferably, clays are used for this purpose, for example kaolin,attapulgite, Fuller's Earth, bentonite, montmorillonite and
smectite clays. Some of the clays, especially the smectite
clays, can have a fabric softening action in the wash after
their removal from the bags in use.
Mixtures of protecting agents may be used, especially mix-
tures of the liquid or waxy solids with the finely-divided inor-
ganic materials. The former can thereby assist the adhesion of
the latter to the sheet material to enhance the protective
effect.
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In the case of the coating ma-terial bein~ a ~:rax,it is
preferably applied to the sheet material before lt is formed
into the bags by passing the sheet ma.terial -through a bath
of wax or by spr~aying on -the wax, ei-ther as a hot melt or
preferably in solution or as an agueous emulsion. ~he
gravure printing process used for waxing paper, such as
operated by George Makin ~imited, ManGhes-ter, ~ngland, is
suitable Por such process. ~he wa-ter or organic solvent
used to apply the wax in -this way is later removed, for
example by hea-ting, and this facilitates the more uniform
application of the wax to the shee-t: material at acceptable
levels. ~he particulate inorganiG'protecting agents such
as clays should be applied by coating, impregnating, padding
or spraying on an aqueous organic.solvent suspension, or
preferably in admixture with the liquid or waxy solid
materials. In the case of a removable ~ater-insoluble
protect;;~e agent , the amount thereof`used is advantageously
.. about 0.~% to about 50%~ preferably~about 1 - 20% by weight
based on the sheet materia.l. ~ hese trea-tments also minimise
dusting, and protect the bag materiai.from attack by -the .
detergent compositionsD If the layer of water-soluble or
removable water-insoluble material is discon-tinuous it is -
preferably attached for support to the water-soluble sheet
material and may be applied there~o'by impregna-tion,
25 - saturation or coating. '.
When a sheet material is used'coated with a dis-
continuous water-soluble or remov~bIe water-insoluble
layer, the pore size of the coated.sheet material should
be such that there is no excessive:dusting of the deterO~ent
~0 composition through the material of the bags in the dry
state~ but preferably no-t so small that wa-ter c~nnot pass
readil-g through the material forming the bags to disperse
and dissolve the con-tents when the product is used~ ~he
preferred level of coating is thus a function of the pore
~5 size distribution of -the uncoated pag'material, :the
particle size distribution of the de-tergent comp~sition
and -the acceptable degree of dusting. ~or optim~m
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properties the degree of dusting is such that no more than about
5%, by weight, preferably no more than about 1%, of the deter-
gent composition particles can pass through the coated sheet
material. With very fine powders, for example made by dry mix-
ing, the maximum pore size of the treated sheet material must be
very small, preferably so as to retain only detergent particles
greater than about 20 microns. With coarser grained detergent
compositions the maximum pore size of the treated sheet material
may be larger so as to retain detergent particles greater than
about 100 microns, e.g. about 500 up to about 1000 microns, as
appropriate. It may be noted that larger pore sizes are generally
better for dissolving powder quickly, but this puts more con-
straints on the powder processing techniques which can be used
in order to avoid e~cessive dusting.
Where the bag material is water-permeable paper or non- -
woven fabric of high wet strength weighing about 10 to about
60 g/m , or other material having a similar pore s`ize distribu-
tion, a coating thicknesc of from about 15 m/g2 to about 45 g/m2,
advantageously about 30 g/m2, is preferred.
The bags can be formed from a single folded sheet formed
into a tubular section, or from two sheets of the material
bonded together at the edges. For example, the bags can be
sachets formed from single folded sheets and sealed on three
sides or from two sheets sealed on four sides for the preferred
rectangular shape. Alternatively, the sheets can be folded like
envelopes with overlapping flaps to be sealed. Other bag shapes
or constructions, for example circular cushion shaped sachets or
of tetrahedron form, may be used if desired. The bags may also
be reinforced, if desired, to decrease the risk of leakage during
handling, for example by adding an extra thickness of the sheet
material where the bags are expected to be held or passing com-
pletely round the bags to help support the weight of detergent
powder.
The bags may be sealed by heat-sealing, cold pressure
sealing or with an adhesive. In the case of heat-sealing
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the bag material should contain at leas-t a minor proportior~
of a thermoplastic ma-terial, such as polypropylene.
~lternatively, the bag material may be coa-ted with a layer
of heat-sealable ~r pressure sealable material such as a
vinyl acetate/vinyl chloride copolymer~
~ o increase the ra-te of dispersion and dissolu-tion of
the detergent composi-tion in the wash liquor, the bag may
be adap-ted -to open in the wash, for example by bursting
at a weak seal or along a perforation line, by the dis-
integration o -the bag material itself'or by at least one
of the seal~ being formed with a water-soluble adhesive that
will dissolve in the wash liquor. ~he"invention is also
applicable to bags that do not open in -the wash.
Any detergen-t composition in particulate form can be
packaged to advantage in the produc-t of the invention. As
an alter~at_vc to a fully formulated detergent composition
(that is a co~position containing at least a surfactant and
a builder? tne bags may contain any one or more of the
- following fabric treatment mate`rials: bleaches such as
sodium perborate; bleach precursors such'as tetraacetylethylene
diamine (~AE~); fabric softeners such as'quaternary ammonium
compounds, starch, perfumes, anti-bacterial agents; stain
removing agents and the like. I-t can be of particular
advantage to add fabric -treatment materials to the wash in a
bag while dosing a fully formulated detergent ~omposition in
a conventional manner, where the incorporation of the fabric
treatment material in the fully formulated detergent
composition may o-therwise be difficult. ~QiS iS of
particular importance in the cas~ of' perfu1lles., bleaches,
bleach precursors and cationic fabric softening agents.
~ he fully formulated compos'itions w~Lch can be packaged
-to advanta~e in the produc-ts of the invention are amply
described in`the literature, for example in "~urface ~ctive
Agents and Detergents", Volumes I and II',~by ~chwartz,
~5 Perry and Berch.
However, the products of -the inven-tion are advantageous-
ly used for detergents powders containing insolub1e
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_ 9 _ C.104~/3
ingredients. Specific examples of such ingredients
include finely divided calcium carbonate, the use of whicrL
-is described in UK patent No. 1 437 950, and sodium
aluminosilica-te ion-exchange materials as.described in UK
patent specifications Nos. 1 429 143, 1 473 201 and
1 473 202.
It is also advantageous to us.e t~e pro~ucts of this
invention with de-tergent composi-tions containing bleach
sys-tems, particularly containing ~AED and sodium perborate.
In addition, the de-tergent products of the invention
. are particularly suited for detergent compositions of
.relatively high bulk densi-ty, i.e. over about 0.5 g/cc,
preferably about 0.6 to 0.8 g/cc, up to a maximum of about
1 g/cc, above which there tends to be. a reduction in the
rate of water solubili.ty or dispersibili-ty. ~he use of
high bu~r de~sity compositions makes it possible to
decrease the size of the detergent~bags whils-t still
containing enough particulate detergent composition to be
fully effective during use. This also enables -the use of
simple processing techniques for the production of the
- detergent compositions themselves, e~g. granulation or dr~
mixing instead of traditional spray drying techniques.
If desired, the sheet material used to form the bag
- can be marked or tagged so that it can be easily recognised
amongs-t the washed fabrics, for example the material may be
printed with a simulated fabric patterns such as check or
gingham~ It can then either be disGarded, or; if desired,
it may be constructed of a suitable.material to proyide it
with a secondar-~ use, for exampl0:as:`a cleaning cloth.
If desired7 the bags can be formed with more than one
separate compar-tment:-Gontai.~i.ng differen-t detergent
I ingrad-e~ts or the bags ma~ be formed in a conjoined manner,
for exa~ple in.a s-trip:to facilita-te dosing of different
numbers of the bags as appropriate for the wash conditions~
~he use of multi-compartment bags t`acilitates the use of
detergent ingredients which would otherwise in-teract with
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other ingredients in detergent compositions, whilst avoiding
encapsulation or other treatment to prevent contact between
such ingreaients in a single composition.
For example one compartment may contain a fully formulated
detergent free of bleach while a second compartment may contain
the bleach. A third compartment may contain a fabric softener.
The invention is illustrated by reference to the follow- -
ing Examples in which parts and percentages are by weight
except where otherwise indicated.
EXAMPLES 1 to 3
Bags for detergent compositions were constructed with a
laminated construction~having a water-soluble polyvinyl alco-
hol sheet (HI-SELON C ~ ) of thickness 0.0015 inch inside water- -
insoluble sheet materials as follows: -
EXAMPLE 1 - Manila hemp with viscose wet strength agent
21 g/m2)
EXAMPLE 2 - Manila hemp fibres treated with Kymene/poly-
meric wet strength agent and with a 20:80 vinyl acetaie/vinyl --
chloride copolymer as heat sealing agent. Weight 27 g/m2.
EXAMPLE 3 - Highly porous polypropylene spun-bonded non-
woven fabric. Weight 10 g/m . ~:-
All three types of bags were made by folding t~e super- -
imposed water-soluble and water-insoluble sheet materials -
(former inside) ~nd then heat-sealing along the two opposing
edges. 84 g of a detergent composition of high bulk density
(0.68 g/cc) prepared by a granulation process as described
in Belgian patent No. 867 038 to the formulation below was
then added to the bags which were heat sealed along the ~pen
edges to form sachets (4 1/2" x 4 1/2"). ---
3~
Ingredient
Nonionic detergent surfactant 14.0
Sodium carbonate 34.0
Calcium carbonate (80 m2/g) 18.0 --
Sodium perborate 25.0
Sodium carboxymethylcellulose 3.3
Fluorescent agent, perfume 1.0
Water 4.7 --
The bags were found to exhibit improved storage properties
under high relative humidities and to give good detergent prop-
erties in use. The bags of Example 1 and 2 opened within 2
minutes in the wash, the first by dissolving the polyvinyl alco-
hol sheet which also formed the seal, and in Example 2 by burst- -
ing the bags along a seam. `The bags of Example 3 did not open --
in the wash but liberated their contents through the highly por-
ous polypropylene sheet material after dissolution of the poly-
vinyl alcohol sheet, under the vigorous agitation in the washing
machines. --~
EXAMæLE 4
Sheets of Manila hemp with viscose wet strength agent
(21 g/m2) were treated with an even coating of a water-insoluble
polyvinyl acetate homopolymer obtained from National Adhesives
and Resins Limited, Slough, ~ngland. The coating material, in
the form of an aqueous dispersion, was spread evenly on one side
of each sheet using a c~lindrical metal rod. The treated sheets
were dried in air. On examination it appeared that the coating
had penetrated the paper. Bags were prepared from these treated
sheets by heat sealing, the bags containing 80 g of a carbonate/
calcite powder as used in Examples 1 to 3. The bags were 4 1/2" --
x 4 1/2". None of the bags gave unacceptable dusting during
handling. These bags were examined to determine whether tne pow-
der was released into the drum of a front loading automatic wash-
ing machine after agitation for 2 minutes. It was found that
bags having a coating of 19 or 22 g/m2 were open and empty after
2 minutes.
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XAMPIE 5~
Bags were prepared as in Example 4 above, but
-containing 60 g of a carbona-te/calci-te powder containing
percarbona-te. `~he bags were s-tored'.at.20C/90% P~
-together wi-th con-trol bags made of untrea-ted Manila hemp
with viscose we-t s-trength agent, provided with a coa-ting
of polyvinyl acetate on the edges only9,for heat sealing
purposes. ~he bags were examined at'weekly intervals
to de-termine whether -the coatings had'conferred resistance
to degradation on the bag material. ;~he results were
as follows: ,
Wei ~ ~ime taken to de~rade
0 (Control) 1 week
19 3 weeks
15 22 ' 2 weeks
37 ' ~ weeks
'"4'weeks
~ hese results show that wi-th this particular coating
material a coating weight of not less'than about 19 g/m2
gives improved stability against degradation.
~ xample 5 was repea-ted with ~arious ~bag'materia'ls and
coating materials. Bag material degradat-ion was assessed from
the bréaking strengths of 1 cm wide strips cut from the bags
after storage. The results were:
~ .ag ... ;.Coati~g ' Goating. .S-torage ~reaking
'material material ~ h-t time ~ stren ~h
.Sau~.age Clay* 0 g/m 11 days 1041 g
(19 g7m ) 31 g/~2 , ,9 g
. ~7 g/m - 'l630 g
Sausage Silicone 0 g/m2 21 days NI~
^asin7 ~ 4 g/m2 ~59 g
~ea bag , 0 g/m2 37 g
~aper 2 5 g/m2 f 251 g
~5 * 'IDinkie-A" -- Regis-tered ~rade Mark.
