Note: Descriptions are shown in the official language in which they were submitted.
1 LAUNDRY AID
BACKGROUND OF THE INVENTION
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The present invention deals broadly with the problems
of using various laundry additives, such as fabric softeners,
detergents, presoaks, bleaches and the like, in the washer
and/or dryer phases of the laundering process. Introducing
such additives at the right time in a neat, clean and -~
convenient manner is often a problem. Giving such additives
an acceptable merchandising appearance is another. In addition
to arriving at a multifaceted solution to some of these
~roblems, we have additionally solved another wash day
problem in a totally unexpected way.
Adding fabric softener at just the right time during
the washer/dryer operation is the additive timing problem most
often encountered. Because fabric softeners are cationic
and many detergents are anionic, the two tend to work against
one another when the fabric sof~ener is introduced into the
washing cycle. Also, many soils are anionic and tend to be
precipitated back onto the clothing by the cationic fabric
~0 softeners present in the wash cycle. Consequently, softeners
have traditionally been added during the washer rinse cycle
rather than the wash cycle. Some washing machines have been
mallufactured with special dispensers so that the sotener
could be placed in the dispenser at the beginning of the
wash cycle, but would not be introduced into the washer tub
until the rinse cycle.
In United States Patent 3,267,701 to Mandarino, it
is suggested that the softener be added to the clothing in
the clothes dryer, rather than in the washing machine.
Others had previously suggested adding other types of laundry
additives to clothing during~the drying operation, as for
r ~
~; ~' ~ . i i`,
1 example United States Patent 2,941,309 to Cobb. Cobb suggests
introducing moisture in the dryer by tumbling the clothes
with a ball having small openings and containing water.
This enhances the fabric by making it easier to iron. United
States Pa~ent 3,442,692 to Gaiser illustrates a method for
adding a fabric softener to ~he clothing during the dryer
phase by coating a fabric substrate with the cationic fabric
softener and tumbling it directly with the clothes in the
dryer.
United States Patents 3,947,971 to Bauer, 4,004,685
to Mizuno et al., and 4j098,937 to Mizuno et al., all disclose
placing either a solid or semisolid bar of fabric softening
material within a porous envelope, and then intIoducing that
porous envelope into a clothes dryer with clothes being
dried. In United States Patent 3,870,145 to Mizuno, a sponge
impregnated with fabric softener is enclosed within a
porous envelope which is placed in a clothes dryer with
articles of clothing to be dried. All of the Mizuno patents
are designed to be adhered to the dryer vane and to be
2~ reused with successive loads of clothes. A]l of the Mizuno
patents suggest varying the melting temperature of the
fabric softening bar by combining the "additives," the
specific examples being combination of two fabric conditioners
of differing melting points, i.e., stearyl dimethylbenzyl
ammonium chloride and dimethyl dihydrogenated tallow ammonium
chloride.
One problem with many of the approaches calling for
adding the fabric softener to the clothing during the dryer
phase is that the user has to be concerned about an extra
step or operation at the time the clothes are introduced into
the dryer. A special problem with a coated substrate is that
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1 ~he coated substrate has a waxy ~eeling which may be regarded
as a less than desirable merchandising factor.
Some have attempted to solve these problems by devising
ways of introducing fabric softener into the washing machine
at the time of initiation of the wash cycle for timed release
later on in the rinse cycle and/or in the dryer. In United
States Patent 4,082,678 to Pracht et al., it is suggested
that fabric softener be packaged in a sealed pouch whose
solubility is pH sensitive. This sealed pouch is then
packaged along with a pH control agent in a second or outer
porous pouch. When this is introduced into the washer at
the beginning of the wash cycle, the pH control agent dissolves
and prevents the inner pouch, which contains the fabric
softener, from dissolving. When the pH altered water is
pumped out of the washer after the wash cycle, and when
clear rinse water is then introduced into the washer, the
inner pOUC}l dissolves and the fabric softener is released.
Thus the fabric softener performs its primary softening
during the rinse cycle of the washing operation. It is
indicated in this patent that any fabric softener which does
remain in the pouch during the rinse cycle would subsequently
be released in the dryer when the pouch and the clothing are
placed in the dryer.
A similar rather complex system is disclosed in United
States Patent 4,10S,600 to ~ong. The primary difference is that
each fabric softening particle is coated with a material whose
solubility in water is pH sensitive, rather than all of the fabric
softening particles collectively being packaged in a first pouch
whose solubllity is pH sensitive. These individually coated
particles are placed in a poro~s ~eceptacle along with a
pH control agent. The pH control agent dissolves in the wash
--3-
1 cycle and prevents dissolution and dispersion of the coated
fabric softener particles. After the wash water is pumped out
and when the rinse water is introduced, the coating on the
fabric softener particles dissolves and the fabric softener
particles are then dispersed out of the porous container.
These are of course rather complex, single purpose
systems. Another system which attempts to achieve the same
result in a different way is disclosed in United States
Patent 4,113,630 to Hagner et al. In Hagner, a substrate is
coated with a fabric softener which is compounded with a
dispersion inhibitor, consisting for example of paraffinic
waxes~ tallow alcohol, polyhydric alcohols and the like,
which tends to prevent the fabric softener from being dispersed
during the wash cycle. This tends to prevent the fabric
softener from being dispersed in either the wash or rinse
cycles, but allows the fabric softener to operate effectively
during the dryer phase. The substrate is introduced at the
beginning of the wash cycle and is simply carried over to
the dryer phase a~ong with all of the clothing after the
washing machine has completed its function.
It is additionally suggested in this patent -that
a deter~ent coating can be loaded onto one of and between two
layers. The fabric softener coating is spaced on the surface
of the substrate so that water can pass through the substrate
layers and dissolve the detergent.
One problem with this approach is that a rather
large substrate is needed to both spread the fahric softening
compound and the detergen-t out and still leave the substrate
permeable so that water can access the detergent inside the
substrate. Also there may be some tendency for the fabric
softener coating to disintegrate or dissolve during the
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5~2~
1 wash and rinse cycles because of the rather large surface
area exposed to attack by the agitator, hot water, detergents
and clothing in the washing machine.
United States Patent 4,203,851 to Ramachandran is
an example of an attempt to incorporate a fabric softener
directly into a detergent composition. A detergent builder
is prepared in bead form and the detergent builder beads are
then impregnated with a fabric softening agent. It is
suggested that the beads may be a mixture of zeolite, sodium
bicarbonate and sodium silicate. It is stated that because
the fabric softener is absorbed into the builder beads, it
tends to disperse more slowly, thereby causing a greater
quantity of the fabric softener to be dispersed during the
later stages of the wash cycle, after the detersive agents
have had a greater opportunity to combine with and remove
dirt from the clothing. One problem with this approach is
that the cationic material would tend to increase redeposition
of dirt on the fabrics.
A review of the above prior art illustrates the
difficulty of introducing laundry additives, especially fabric
softener, into the washer/dryer operation at the proper time
and in an economically effective and aesthetically pleasing
way.
SU~ARY OF THE INV~NTION
_
In the present invention, the timing problem for
adding laundry additives is solved with respect to multiple
additives by placing at least two different additives in a
porous container, one or more belng a washer phase effective
agent which will dispense from the container as water flows
around and through the container during the wash cycle, and
the other being a typically dryer phase effective agent in a
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~z~
1 form which will not pass through the pores of the porous
container, and being selected -from the group consisting of
either (1) agents which will resist any subs~antial dispens-
ing and/or activation in water at temperatures normal for
wash water in washers but which will be activated and/or
dispensed at temperatures at which dryers normally operate
so as to pass through the pores of the porous container, and
(2) agents compounded with other components, which as compounded,
will similarly resist any substantial dispensing or activation
in hot water but will be dispensed and/or activated in the
dryer. This invention facilitates automatically timing the
addition of different additives at different points during
the washer/dryer operation, yet allows all of the additives
to be added at the beginning of the wash cycle approximately
simultaneously with the introduction of articles of clothing
into the washer. Yet ~his is achieved in a very straightforward
and economical manner by simply placing the two agents in a
common porolls container9 without the need for utilizing any
coating techniques, special p~ control agents or the like.
Because substrate coating is avoided, the pouch can be
relatively small, and additives can be designed for dispersion
during the dryer phase to have less exposed surface area
and hence be less subject to attack during the wash cycle.
The term "laundry additivel~ is intended to broadly
include any material which helps make the clothing cleaner,
softer and otherwise more desirable. Thus the term is used
herein to describe such diverse compounds as water softeners,
fabric softeners, anti-static agents, presoaks, bleaches,
waterproofing agents, germicides, sizing agents, soil release
agents, detergents, brighteners, blueing agents, soaps,
fabric fresheners (fragrances), deodorants, anti-wrinkling
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1 additives and the like.
While the multiple additive embodiment of the
invention is most preferred, it is also unique and
advantageous to dispense in pouch form fabric softening
agent alone by adding the pouch at the beginning of the
wash cycle.
Another aspect of this invention ma~ involve placing
a water softening agent in the pouch, either alone or with
other laundry additives as described above, and placing the
pouch in the washing machine at the beginning of the wash
cycle. Thus, excess water softener need not be formulated
into a laundry detergent composition per se in order to
utilize the laundry detergent in harder water. Rather, it
is made available in a convenient, ready to use pouch contain-
ing a premeasured amount of wateT softener.
These and other aspects, advantages and features
of the present invention will be more fully understood and
appreciated by reference to the appended drawings and the
description of the preferred embodiment.
2~ BRIEF DESCRIPTION OF lHE DRAI~ING
Fig. 1 shows an article made in accordance with
the most preferred embodiment of the invention.
DESCRIPTION OF T~IE PREFERRED EMBODIMENT
In the preferred embodiment, a porous container or
pouch 10 contains water softener particles 20 as the washer
phase effective fabric enhanc~ng agent and a fabric softening
wafer 50 as the dryer phase effective fabric enhancing agent
~Fig. 1). Each of the water softener particles 20 is
larger than the pores of pouch 10 when dry. If a water in-
soluble water softener is used, particles 20 divide into a
plurality of fine, insoluble water softening particles when
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~-.
1 placed in wash water, which are smaller than the pores in
pouch 10. I-f a water soluble softener is used particles 20
of course dissolve. Pouch 10 is placed in the washing
machine at about the same time detergent is added. The
water softening particles 20 disperse through the pores of
porous container 10 by one of the aforesaid mechanisms.
Fabric softening wafer 50 is compounded to resist deteriora-
tion in water temperatures typical for washing machines in
hot water (as for example as high as 55C) and hence remains
integral or substantially so, within pouch 10 during the
wash and rinse cycles in the washing machine. Pouch 10 is
then carried along with any articles of clothing into the
dryer. Under the heat of the dryer ~usually 60C. or more),
the fabric softening wafer 50 melts and the fabric softening
material passes through the porous container 10 and is
intermingled with articles of clothing.
Porous container 10 is pre~erably made o~ a flexible
fabric material so that it has less tendency to abrade any
articles of clothing with which it is mingled. The material
2n should be strong and tear resistant. The porous material of
which pouch 10 is made must exhibit sufficient wet strength
to maintain structural integrity in the washer and dryer.
It should not melt or ignite in a hot dryer.
Most preferably, porous container 10 is made of a
material which is flexible, porous and can be heat sealed.
One example is a nonwoven spun bonded polyester manufactured
by the Dupont Company under the trademark "REEMAY." The
most preferred material is a nonwoven cotton polyester
material with a porous polyethylene coating on one side to
facilitate heat sealing. Such material is manufactured ~y
the Stearns and Foster company under the trademark "IRONTITE."
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1 Pouch 10 is formed preferably by folding and heat
sealing the edges of a sheet of this porous material, at 11
in ~ig. 1. Ultrasonic sealing is a viable alternative.
Alternative materials exhibiting similar properties
would of course be acceptable. Cellulose, coated with a
thermal plastic material to render it heat sealable, is an
example of a material which might be acceptable. Spun
bonded or nonwoven polypropylene, cloth and other fiber
woven materials, certain papers, porous polymer sheets, thin
porous foam sheets, porous foil, sponge, are examples of
other pouch materials which might be used. Alternative edge
sealing means can be usedt as for example, sewing or glueing.
Some latitude in porosity of the fabric material
of which porous container 10 is made is possible. If the
water softening agent is water soluble, the porosity of the
fabric can be quite low9 though not so low as to render
the fabric waterproof. If an insoluble water softening agent
is used, as would be the case with zeolite, the porosity should
be as large as possible to allow rapid dispersion of the
zeolite by the wash solution, and yet retain the zeolite in
porous container 10 when it is dry.
Since for laundry grade zeolite the majority of
its individual particles are from about 2 to 10 microns in
size, with the remainder varying up to about lO0 microns,
the porosity of porous container 10 must be suf~iciently
great to dispense particles of up to about 100 microns. It
is preferable that these fine particles be agglomerated into
larger particles, either inherently during processing as
occurs with zeolite, or through intentional processing using
any of a number of known agglomerating agents~ so that the
porosity of porous container 10 can be somewhat greater than
g
1 if the particles were not agglomerated. This malces it
possible for the particles of up to 100 microns to dispense
more rapidly, yet still retains the agglomerated particles
within porous container 10 when they are dry.
One way to measure the porosity of fabric is
through Frazer air permeability. For dispensing zeolite
water softening particles, we have found that the fabric of
which container 10 is made should have a Frazer air perme-
ability of from about 200 cu.ft./min/sq.ft. to about 600.
When the fabric has an air permeability of less than about
200, it does not dispense zeolite particles satisfactorily.
When it is greater than about 600, the zeolite tends to
dust out of container 10 too readily.
As will be apparent to those skilled in the art,
lS the relative porosity of container 10 will thus to a great
extent be a function of the particular water softener used.
However, the principles discussed above will enable the
skilled artisan to select a particular porosity which will
be appropriate for the particular water softening agent
selec.ted.
A sufficient quantity of active water softening
ingredients should be placed in container 10 to meaningfully
soften a typlcal washer load of hard water. ~'or example,
most washers hold from 35 to 95 liters of water. Hardness
e~countered typically ranges up to about ~OOppm. It
is preferable to reduce this hardness to about 50ppm. The
quantity of actlve water softening ingredients will thus
vary depending on the relative effectiveness of the water
softener per unit of weight. '[he preferred~water softener
in the present invention is zeolite. ln the case of zeollte,
we have found it desirable to employ from about 2Q to about
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1 100 grams and most preferably 3~ to 70 grams of finely
divided zeolite particles in porous container lU.
~e have found, however, that while intentional
agglomeration using any of various known agglomerating agents
may help minimize "dusting" during handling the package, the
preferred particle 20 comprising relative fine zeolite particles
simply agglomerated to or.e ano~her inherently during manu-
facturing appears to be sa~isfactory for purposes of the
present invention. Such agglomerated partlcles substantially
fall within the range of from about 500 to about iO00 microns
when dry, yet divide into much finer particles, substantially
of from about 2 to about lU microns with some being as
large as about 100 microns~ when exposed to wash water. ln
terms of all practical considerations, such inherently
agglomerated zeolite is regarded as the best mode for practicing
this invention.
The particular zeolite selected mus~ be a laundry
effective zeolite. Zeolite A lS widely recognized as the
most effective water softening zeolite for laundry use.
Zeolite A is generally understood to encompass`a water
insoluble aluminosilicate of the general formula:
MrlO:A1203:XSiO2:y~2o
where X has a value o~ from .8 to ~, more typically 1.0 to
2.0 and most typically 1.85 ~ .5. Y is a number of from
about 2.5 to about 6. M is an alkali metal capable of
exchange with calcium and n is its valence.
In a grain diameter of from about .1 to about 100
microns, this material has a calcium ion exchange power of
at least 50mg calcium ion and most preferably 200mg calcium
ion equivalent/gm and a calcium ion exchange speed of at
least about 9ppm calcium ion/l/mirl/g. As a percent by weight,
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1 the water comprises lO to 2~%.
In order to be most effective, the zeolite particles
must be very finely divided when dispersed ln water, thereby
creating a large active surface area. The vast majority of
the particles in our preferred composition are from 2 to 5
microns. Most are under 10 microns, though some particles
may be as large as 100 microns without adversely affecting
the effectiveness of the zeolite.
The preferred dryer phase effective agent in
accordance with the present invention is a fabric softener/
antistat. The fabric softener/antistat must resist any
- substantial dispensing and/or activation in hot water at
temperatures normally introduced into washing machines, but
must dispense and/or activate at temperatures at which
dryers normally operate so that it will pass through the
pores of porous container 10. Alternatively~ a fabric
softening/antistat composition must be compounded with other
components so that the material as compounded will resist
any substantial dispensing and/or activation in hot water,
~ut will dispense and/or activate and pass through the pores
oE porous container 10 in the hot dryer. The typical wash
water temperature in most homes is from 20C. to 55C. The
typical dryer temperature is around 60C., though some
laundromat dryers will generate temperatures of up to 90C.
We have found it most preferable to mix the fabric
softener/antistat with zeolite, most preferably zeolite A.
Zeolite inhibits dispersion of the fabric softener/antistat
in the washing machine, and controls release in the dryer
so that dispersion is more uniform. Zeolite also makes a
wafer form of the softener/antistat, which is preferred,
more fracture resistant and thus helps it hold up better in
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~2~S~
1 the washing machine. The quantity of zeolite employed must
be within a range which will achieve the following objectives
1. yield good endurance in the
washing machine so as to maximize
S the quantity of fabric softener/
antistat which is still available
for activation in the dryer;
2. optimize melting in the dryer,
which too much zeolite inhibits;
and
3. provide controlled release of the
fabric softener/antistat during
the dryer phase to thereby contTol
and minimize spotting on the clothes.
In order to maximize these goals the quantity of zeolite
used is to some extent a function of the particular softener/
antistat selected. We have found however, that one would
typically employ from about 5 ~o about 60~ by weight zeolite.
This composite resists disintegration in 55C., wash water,
but dispenses readily in a 60C.g dryer. In the most preferred
embodiment~ the fabric softener/antistat is present in
porous container 10 in wafer form 50, rather than as granules
or a powder. II1 wafer formr the fabric softener/antistat
more readily resists disintegration in -the hot, wash water
as there is far less surface area exposed to attack by the
agitated, hot water.
While it is most preferable to compound zeolite A
into the fabric softener wafer 50, other insoluble inorganic
materials are operable. Other materials which might be
operable, though not as effective as zeolite A for this
purpose include other zeolites, fumed silica, bentonite,
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1 kaolin clay, calcium phosphate, diatomaceous earth, organic
clays, and other porous insoluble agents.
We ha~e addi~ionally found it desira~le to incorporate
an activation inhibitor into the fabric softener wafer. The
preferred inhibitor is stearyl alcohol, which decreases the
solubility of the stearyl alcohol and fabric softener mixture,
thereby further helping to minimize activation and dispensing
of the fabric softener in the washing machine. Other
activation inhibitors include tallow alcohol, other fatty
alcohols in the C14 to C26 range, such as myristyl alcohol,
cetyl alcohol, stearyl alcohol, arachidyl alcohol, behenyl
alcohol, and mixtures thereof. To make such a wafer, the
fabric softener/antistat and the stearyl alcohol are melted
and the zeolite powder is mixed in and dispersed. The
lS resulting melt mixture is poured or formed and allowed to
cool. The use of both stearyl alcohol and zeolite as a
dispersion inhibiting mixture has been found particularly
ef-fective in that one can use somewhat less zeolite than
would be required if no stearyl alcohol ~ere used. This is
desirable in that if one has too much zeolite in wafer 50,
it may overly inhibit melting of the fabric softenerJantistat
within the dryer.
While the relative quantities of zeolite and
stearyl alcohol will vary somewhat depending on the particular
fabric softener/antistat used, we have found the following
ranges satisfactory:
softener/antistat 40 to 90% by weight;
zeolite 5 to 60% by weight;
stearyl alcohol 5 to 55% by weight.
As discussed more fully below, we prefer to employ
a mixture of dimethyldihydrogenated tallow ammonium methyl
-14-
~ 2~
1 sulfate fabric softener with a nonionic antistatic agent. In
the case of this particular mixture, we have found that the
most preferred wafer composition is as follo~s:
soft~ner/antistat mix 35 to 50~ by ~eight;
zeolite 35 to 50% hy weight;
stearyl alcohol 10 to 30% by weight.
A rather wide variety of conventionally known fabric
softening materials might be compounded with zeolite and
possibly stearyl alcohol in this manner to yield a wafer 50
which will resist disintegration in hot wash water at
temperatures as high as 55C.g yet which will readily disperse
and/or activate in hot dryer temperatures of in excess of
60C~ We prefer to employ a mixture o-f dimethyl dihydrogenated
tallow ammonium methyl sulfate fabric softener with a nonionic
antistatic agent. We prefer the sulfate ~ùaternarium ammonium
compounds. However, other quaternary ammonium compounds, many
of which are well-known in the art as fabric softeners, can
be used. These include dicetyldimethylammonium chloride,
bis-docosyldimethylammonium chloride, diclodecyl-dimethylammonium
chloridel ditallowalkyldimethylammonium bromide, dioleoyl-
dimethylammonium hydroxide, ditallowalkyldiethylammonium
chloride, ditallowalkyldipropylammonium bromide, ditallowalk-
yldibutylammonium fluoride, cetyldecylmethylethylammonium
chloride, tris-[ditallowalkyldimethylammonium] phosphate,
and the like.
Nonionic antistatic agents are well-known to those
skilled in the art. ~e prefer an ethoxylated stearic acid.
Howe~er, other nonionic antistatic agents could ~e used.
These include other ethoxylated fatty acids, fatty alcohols,
fatty acids, fatty glycerides, polyethylene glycols, amine
oxides. diamine compounds, alkyl amines, and the like. In
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S~
terms of ~he parameters of the present inven~ion, it is of
primary importance to select a sof~ener compoun~ which is
either relatively water insoluble in and of itself or is
relatively insoluble when combined with activa~ion inhibitors
such as stearyl alcohol and zeolite discussed above. This
solubility limitation is very important in that wafer 50
must not dissolve or disperse during the wash or rinse
cycles of the washing machine phase of the laundry operation.
Many cationic compounds are also known to be
effective antistatic agents. These include, quaternary
ammonium salts, quaternary imidazolinium salts, alkyl
pryidinium salts, alkyl morpholinium salts, and quaternary
derivatives of amino esters and am;no aci~s~ cationic
functional silicones, and the like. As with the fabric
so~teners, such antistatic agents must be selected so as to
be relatively water insoluble, either per se or when compounded
with the activation inhibitors discussed above.
Sufficient fabric softener/antistat should be
incorporated into wafer 50 to soften a typical load of
laundry. Thus wafer 50 should preferably contain from about
.2 to about 10 grams by weight of active fabric softening/
antistat ingredientg most preferably 1 to 2.5 grams. The
zeolite A compounded into wafer 50 to assist in resisting
disintegration, and reducing fabric softener spotting, would
not be an active fabric softening or static con~rolling
ingredient. The total weight of wafer 50, including both
active and inactive ingredients is from about Q.5 to about
20 grams, most preferably 3 to 5 grams.
The fabric enhancing agents described above in
connection with the most preferred embodiment of this invention
comprise a water softening agent and a fabric softening/antistatic
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~s~
1 agent, respectively. Obviously, other fabric enhancing
agents could be incorporated into porous container 10 in
accordance with the broader aspects of the presen~ invention.
Examples of washer e-ffective fabric enhancing agents which
could be employed include presoaks, chlorine bleaches,
detergents, oxygen bleaches, alkalinity boosters, water
softeners, soaps 9 optical brighteners, fabric softeners,
germicides, waterproofing agents, sizing agents, soil release
agents, fabric fresheners (fragrances~, deodorants, anti-
wrinkle additives and the like. Examples of other dryer
effec~ive fabric enhancing agents which could be incorporated
into the present invention include optical brighteners,
waterproofing agents, hydrophilic fabric finishes, germicides,
sizing agents, soil release agents, fabric fresheners
(fragrances), deodorants, anti-wrinkle additives and the
like. Thus it is understood that the above is merely a
preferred embo~iment of the invention and that various
changes and alterations can be made without departing from
the spirit and broader aspects thereof, as set forth in the
appended claims which are to be interpreted in accordance
with the principles of patent law, including the doctrine of
equivalents.
