Note: Descriptions are shown in the official language in which they were submitted.
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LIO~ID FABRIC CONDITIONER AND DRYER SHEET
FABRIC CONDITIONER CONTAINING FABRIC SO~l~.~K,
AMINOSILICONE AND BRONSTED ACID COMPATIBILISER
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The instant invention relates in a first aspect to
conditioning of fabrics in an aqueous wash bath, to liquid
compositions containing fabric conditioning ingredients
and to processes for making the compositions. In a second
aspect the invention relates to fabrics in tumble-dryer
automatic dryers. More particularly, it relates to an
article in the form of a flexible substrate carrying a
fabric conditioning composition.
RELATED ART
Silicones have been applied to fabrics during manufacture
of fabrics or during the make up of articles of clothing.
With respect to application of silicones to fabrics during
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a laundry process, Great Britain Patent Application
1,549,480; Burmeister et al., U.S. Patent 4,818,242;
Konig et al., U.S. Patent 4,724,089; Konig et al., U.S.
Patent 4,806,255; Dekker et al., U.S. Patent 4,661,267
and Trinh et al., U.S. Patent 4,661,269 describe aqueous
dispersions or emsulsion of certain silicones of limited
viscosity incorporated in liquid rinse-cycle fabric
softening compositions. A fabric softening composition
containing emulsified silicone is taught by Barrat et al
in U.S. Patent 4,446,033. The rinse compositions taught
by the '089, '255, '267 and '269 patents contain cyclic
amine fabric softening agents and employ water-soluble
Bronsted acids to control the pH of the aqueous
compositions for proper dispersion of the amine.
The compositions disclosed in the art contain individual
particles of a silicone and individual particles of a
fabric softening agent.
Wells, U.S. Patent 4,308,024 discloses non-silicone
fabric softening compositions consisting essentially of a
water-insoluble cationic detergent surfactant and a
C8-C24 alkyl- or alkenyl monocarboxylic acid.
The application of fabric softeners to fabrics in the
tumble dryer by use of a flexible substrate carrying the
fabric softeners is known in the art. The advantages of
dryer added fabric conditioning include a more convenient
time of addition in the laundry process and avoidance of
undesirable interaction of softening agents with
detergents.
Rudy et al., U.S. Patent 3,972,131 discloses dryer sheets
including a silicone oil as an ironing aid. Kasprzak et
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al., U.S. Patent 4,767,548 discloses the use of certain
silicones in dryer sheet formulations.
Coffindaffer et al, U.S. Patent 4,800,026 discloses
curable amine functional silicones in fabric care
compositions.
Japanese Patent Application 62/78,277 discloses _
chemically combined condensation products of amino
modified silicone oils as softeners.
In the manufacture of the dryer added fabric conditioning
sheets described in some of the references mentioned
above, when silicones are mixed with fabric softeners,
the resulting mixtures are non-homogeneous and phase
separation occurs readily. The homogeneity of such
mixtures is ensured only by continuous vigorous
agitation. An additional problem associated with the use
of a nonhomogeneous mixture is the separation of actives
at the point of application of the active mixture on the
substrate resulting in unevenly impregnated sheets.
Bronsted acids described herein compatibilise
aminosilicones with fabric softening agents. In the
present invention the dispersed particle is a composite
particle containing a mutually soluble mixture of an
aminosilicone, a fabric softening component and a
Bronsted acid.
Critically, the aminosilicones in the composite particles
of the present invention do not separate from the fabric
softening agent during processing, on standing, during
coating or solidifying on the dryer sheets. An
additional advantage afforded by the present invention is
a simplified manufacture of fabric conditioning liquids
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since silicone no longer has to be dispersed separately
and can be introduced into the composition simultaneously
with a fabric softener.
Accordingly, it is a first object of the present
invention to provide a liquid fabric conditioning
composition which contains composite particles of a
compatible mixture of a fabric softening component, an
aminosilicone and a Bronsted acid.
It is a further object of the invention to provide
processes by which the aforementioned composition can be
manufactured.
Accordingly, it is a further object of the present
invention to provide an article which provides for
release of a fabric conditioning composition within an
automatic laundry dryer, the composition containing a
compatible mixture of a fabric softening component, an
aminosilicone and a Bronsted acid.
These and other objects and advantages will appear as the
description proceeds.
SUMMARY OF THE INVENTION
The present invention is based, in part, on the discovery
that specific Bronsted acids are capable of
compatibilising aminosilicones with certain conventional
fabric softening agents. As a result of the use of
Bronsted acids as described herein mutually compatible
mixtures containing an aminosilicone and a fabric
softening component can be formed.
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Mutual compatibility as taught herein is critical and is
ascertained by the appearance of the mixture containing
an aminosilicone, a fabric softener and a Bronsted acid.
When an aminosilicone, a fabric softener and a Bronsted
acid are heated and mixed together, the resulting liquid
mixtures are either transparent or opaque. In the
transparent mixtures, Bronsted acid compatibilises
aminosilicone with fabric softener and a mutuall~ soluble
mixture containing an aminosilicone, a fabric softener
and a Bronsted acid is formed. Accordingly, transparent
mixtures are suitable for use in the present invention.
In the opaque mixtures an aminosilicone, a fabric
softener and a Bronsted acid are not mutually soluble.
These opaque mixtures are sometimes sufficiently stable
for use as a coating for dryer sheet application.
Thus, the class of compatible mixtures as defined herein
includes mutually soluble mixtures of an aminosilicone, a
fabric softener and a Bronsted acid as well as mixtures
wherein an aminosilicone, a fabric softener and a
Bronsted acid form mutually stable dispersions.
Compatibility of the mixture is critical and is
determined by the Compatibility Test described below.
In its broadest aspect, some objects of the invention are
accomplished by a liquid fabric conditioning composition
which includes about 1% to about 60% of composite
particles containing a mutually compatible mixture of a
fabric softening component, an aminosilicone and a
Bronsted acid. Of course, these particles can also be
added to a liquid containing other fabric treating
ingredients including, for example, softeners. Other
objects of the invention are accomplished by an article
comprising a flexible substrate carrying an effective
amount of a fabric conditioning composition affixed
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thereto in a manner which provides for release of the
conditioning composition within an automatic tumble dryer
at dryer operating temperatures.
The fabric softening component employed herein may be any
commonly used fabric softening agent complying with the
above conditions provided that for liquid compositions it
must include at least a portion of cationic quaternary
ammonium salts used singly or, optionally, in admixture
with other softening agents such as nonionic softeners
selected from the group of tertiary amines having at
least one C8_30 alkyl chain, esters of polyhydric
alcohols, fatty alcohols, ethoxylated fatty alcohols,
alkylphenols, ethoxylated alkylphenols, ethoxylated fatty
amines, ethoxylated monoglycerides, ethoxylated
diglycerides, mineral oils, polyols, carboxylic acids
having at least 8 carbon atoms, and mixtures thereof.
The fabric conditioning compositions of the present
invention include an organosilicone having an amine
functionality, i.e. an aminosilicone.
The compositions also contain Bronsted acids which
compatibilise an aminosilicone with a fabric softening
component. Bronsted acids employed in the present
invention have at least 6 carbon atoms.
A certain amount of Bronsted acid is necessary to
compatibilise an aminosilicone with a fabric softener.
The weight ratio of the Bronsted acid to the combined
weight of the aminosilicone and the fabric softening
component is at least such that a mutually compatible
and, preferably, tranpsarent mixture of a fabric
softening component, an aminosilicone and a Bronsted acid
is formed, as determined by the Compatibility Test.
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Each component of the present compositions: the fabric
softening component, the aminosilicone and the Bronsted
acid may provide fabric conditioning benefits including
softness, fluffiness, static control, and other benefits
when fabrics are comingled with compositions of the
invention in an aqueous bath or in a tumble dryer.
Liquid conditioning compositions of the present invention
include a liquid carrier and may be formulated as diluted
or concentrated products.
DETAILED DESCRIPTION OF THE INVENTION
The liquid fabric conditioning composition of the present
invention includes a cationic quaternary ammonium salt.
The counterion is methylsulfate or any halide.
Examples of cationic quaternary ammonium salts include,
but are not limited to:
1. Acyclic quaternary ammonium salts having at least
two C8 to C30, preferably C12 to C22 alkyl chains, such
as: ditallowdimethyl ammonium chloride, di(hydrogenated
tallow)dimethyl ammonium chloride, distearyldimethyl
ammonium chloride, dicocodimethyl ammonium chloride and
the like;
2. Cyclic quaternary ammonium salts of the
imidazolinium type such as di(hydrogenated
tallow)dimethyl imidazolinium methyl sulfate,
l-ethylene-bis(2-tallow-1-methyl) imidazolinium methyl
sulfate and the like;
3. Diamido quaternary ammonium salts such as:
methyl-bis(hydrogenated tallow amidoethyl)-2-hydroxyethyl
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ammonium methyl sulfate, methyl
bis(tallowamidoethyl)-2-hydroxypropyl ammonium methyl
sulfate and the like;
4. Biodegradable quaternary ammonium salts such as
N,N-di(tallowoyl-oxy-ethyl)-N,N,-dimethyl ammonium
chloride, and N,N-di(tallowoyl-oxy-propyl)-N,N-dimethyl
ammonium chloride and the like. When fabric con~itioning
compositions employ biodegradable quaternary ammonium
salts, the pH of the composition is preferably adjusted
to between about 2 and about 5. Biodegradable quaternary
ammonium salts are described, for example, in U.S.
Patents 4,137,180, 4,767,547 and 4,789,491~
5. Mixtures of water-insoluble cationic fabric softener
and a polyalkoxylated ammonium salt as described in U.S.
Patent 4,422,949. Such mixtures may be particularly
suitable for incorporation in a concentrated form of the
liquid compositions herein.
The fabric softening component may include other fabric
softeners in addition to the cationic quaternary ammonium
salts. Additional fabric softeners suitable for use
herein can be selected from the following classes of
compounds:
i. Tertiary fatty amines having at least one and
preferably two C8 to C30, preferably C12 to C22 alkyl
chains. Examples include hardened tallow amine and
cyclic amines such as l-(hydrogenated
tallow)amidoethyll-2-(hydrogenated tallow) imidazoline.
Cyclic amines which may be employed for the compositions
CA 02043470 1997-11-13
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herein are described in U.S. Patent 4,806,255,
ii. Carboxylic acids having 8 to 30 carbon atoms and one
carboxylic group per molecule. The alkyl portion has 8
to 30, preferably 12 to 22 carbon atoms. The alkyl
portion may be linear or branched, saturated or
unsaturated, with linear saturated alkyl preferr~d.
Stearic and myristic acids are preferred carboxylic acids
for use in the composition herein. Examples of these
carboxylic acids are commercial grades of stearic acid
and the like which may contain small amounts of other
acids.
iii. Esters of polyhydric alcohols such as sorbitan
esters or glycerol stearate. Sorbitan esters are the
condensation products of sorbitol or iso-sorbitol with
fatty acids such as stearic acid. Preferred sorbitan
esters are monoalkyl. A common example of sorbitan ester
is ~SPAN 60(ICI)) which is a mixture of sorbitan and
isosorbide stearates.
iv. Fatty alcohols, ethoxylated fatty alcohols,
alkylphenols, ethoxylated alkylphenols, ethoxylated fatty
amines, ethoxylated monoglycerides and ethoxylated
diglycerides.
v. Mineral oils, and polyols such as polyethylene
glycol.
vi. Condensation products of higher fatty acids with
polyamines, selected from the group consisting of
hydroxyalkyl alkylene diamines and dialkylene triamines
and mixtures thereof, as described in U.S. Patent
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CA 02043470 1997-11-13
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4,661,269.
Preferred fabric softeners for use herein are acyclic
quaternary ammonium salts, di(hydrogenated)tallowdimethyl
ammonium chloride being most preferred for fabric
conditioning compositions of this invention.
When the fabric softening composition is used to coat a
substrate to form an article according to the present
invention the composition includes fabric softeners which
can be used singly or in admixture with each other. The
fabric softeners are selected from the ammonium salts as
mentioned in (1) to (5) above and other softeners as
mentioned in (i) to (vi) above.
About 1% to about 40% of the fabric softening component
is used in the compositions of the invention. There must
be included at least a sufficient amount of quaternary
ammonium salt to achieve anti-static effect, for example
about 1% to about 3% in the dilute product and about 2%
to about 5% in the concentrated product. On the other
hand, the entire fabric softening component may be a
quaternary ammonium salt. The dulited version of the
product contains about 1% to about 12%, preferably about
3% to about 10% and most preferably about 4% to about 7%
of the fabric softening component. The concentrated
version of the product contains about 13% to about 40%,
preferably about 13% to 30% and most preferably about 13%
to about 20% of the fabric softening component.
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Aminosilicone
The second essential ingredient of the fabric softening
composition employed in the present invention is an
aminosilicone. Any organosilicone having an amine
functionality is suitable for use herein. Aminosilicones
employed in the present compositions may be linear,
branched or partially crosslinked, preferably linear.
Particularly suitable aminosilicones are represented by
Formula A:
IC 3 IC 3 IC 3 ICH3
CH3-SiO-(SiO)X-(SiO)y~Si~CH3 FORMULA A
CH3 CH3 (CIH2)a CH3
N-R
( ICH2)b
N-R
wherein x and y are numbers of at least 1; a and b are
numbers from 1 to 10, preferably from 1 to 5; and R is
hydrogen or a hydrocarbon radical, preferably hydrogen.
Preferably, x is a number from 50 to 1000 and the ratio
of y/(x+y) ranges from 1% to 10~. Typically,
aminosilicones having higher amine content exhibit
greater compatibility in the mixtures containing an
aminosilicone, a Bronsted acid and a fabric softener.
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The following list is illustrative of the aminosilicones
employed in this invention:
Name Amine NeutralViscosity
Milliequivalent(cst)
gram of silicone
~Magnasoft Fluid1 0.5 250
~Magnasoft Ultra1 0.5 950
*SSF2 0.5 130
~CSF2 0.5 1300
*Silicone SL 1.26 350
~F-6413 0.07 6000
~F-7513 0.14 500
~F-7843 0.45 50
~F-8083 1.6 20
1Aminosilicone from Union Carbide Corp.
2Aminosilicone from Dow Corning Corp.
3Aminosilicone from Wacker Silicones.
In Silicone SL x=190, y=10, R=hydrogen, a=3 and b=2.
Siliocone SL is most preferred under current empirical
conditions.
Of course, other aminosilicones may be employed.
The aminosilicones included in the compositions herein
may be linear, branched, or partially crosslinked,
preferably linear, and may range from fluid, liquid to
viscous liquid, gum and solid.
The amount of an aminosilicone employed herein typically
is about 0.1% to about 20% of the finished composition,
and is preferably at least about 0.5% to about 2% to
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achieve fabric conditioning benefit at an optimum cost,
but could be higher in concentrated liquids. When the
compositions is used to make articles according to the
invention the amount of the amine functional
organosilicone is about 3% to about 20~ by weight of the
composition.
Bronsted Acid
Bronsted acids suitable for use in the present invention
contain an alkyl group having at least 6 carbon atoms,
preferably 12 to 24 carbon atoms and most preferably 16
to 20 carbon atoms. The alkyl group may be selected from
the group of linear or branched alkyl, linear or branched
alkenyl, linear or branched alkylaryl or alkenylaryl,
linear or branched ethoxylated alcohols, or other alkyl
groups. The acid groups combined with the above alkyl
groups to give suitable Bronsted acids for the present
invention include carboxylic,sulfuric, sulfonic,
phosphonic, phosphinic, phosphoric and
di-alkyl-sulfosuccinic. Bronsted acids employed in the
present invention have 1 to 3 acid groups, and preferably
have 1 acid group. If the Bronsted acid contains 2 or 3
acid groups per molecule, it is preferred that the acid
groups are located structurally close to each other, such
as geminally in the case of di-acids or on adjacent
carbons. Bronsted acids employed in the present
invention may also be substituted with
electron-withdrawing groups such as, for example, a
hydroxy group. Examples of Bronsted acids suitable for
the present invention include but are not limited to:
i. C17H35COOH or other fatty acids;
ii. C11H23-C6H4-SO3H or other alkylaryl sulfonic acids;
2 ~ 1 3 ~ : O
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iii. C14H29-O-(C2H~O)n-R -COOH (wherein n is a number
from 1 to 25 and R is an alkyl group having 1 to 3
carbon atoms);
OH
iv. (R )2-"=~ (wherein R is an alkyl, alkenyl,
alkylaryl, alkenylaryl or other alkyl group) or other
phosphonic acids;
v. CH3-(CH2)m-PO3H2 (wherein m is a number of at least
1) and CH3-(CH2)-O-PO3H2;
vi. R -CH-CH2-COOH (wherein R is an alkyl, alkenyl,
¦ alkylaryl, or other alkyl groups).
COOH
vii. R -O-CO-CH-SO3H
R -O-CO-CH2
(wherein R4 and R5 can be the same or different and can
be alkyl, alkenyl, or alkylaryl and m~y be linear or
branched). Preferably both R4 and R5 are the same linear
alkyl having 6 to 22, most preferably 8 to 18 carbon
atoms.
The weight ratio of the Bronsted acid to the combined
weight of the fabric softening component and the
aminosilicone is from about 1:100 to about 100:1 but must
be at least such that the compatibility among the fabric
softening component, the aminosilicone and the Bronsted
acid is ensured.
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As described above, mixtures defined as compatible herein
include mutually soluble as well as mutually stable
dispersible mixtures. The Compatibility Test is employed
to determine whether the particular amount of Bronsted
acid compatibilises an aminosilicone with a fabric
softening component.
The Compatibility Test is conducted as follows: a 10 gram
sample containing a fabric softening component and an
aminosilicone is placed into a clear glass flask equipped
with a stirring mechanism, such as a magnetic stirrer. A
Bronsted acid in the amount of interest is slowly
introduced with, conveninently, a Pasteur pipet into the
flask, with stirring. If a fabric softening component or
an aminosilicone or a Bronsted acid is a solid at room
temperature, it is melted before the test is begun with
the test taking place above the melting point of the
fabric softener or the aminosilicone or the Bronsted
acid. Thus, compatibility is defined herein with respect
to liquid or liquefied mixtures containing the
aminosilicone, the fabric softening component and the
Bronsted acid.
If the resulting mixture containing the fabric softening
component, the aminosilicone and the Bronsted acid is
clear, this indicates that the components of the mixture
are mutually soluble and, accordingly, are compatible.
Clear mixtures are defined herein as mixtures having
about 90~ transmittance when measured with visible light
probe (one centimeter pathlength) against distilled water
background using Brinkman PC800 colorimeter.
The mixture may also become cloudy, indicating that the
fabric softening component, the aminosilicone and the
2 ~ 5 3 L ~ ~3
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Bronsted acid are not mutually soluble at that weight %
of the Bronsted acid.
Cloudy samples are placed in an oven at 100~C for at
least two hours, then cooled to room temperature and
inspected.
Samples which have completely separated into distinct
layers are compatible and are not useful for the
invention. Samples which maintain a stable, dispersed or
soluble character are compatible and, hance, useful in
the invention. If compatible mixtures solidify on
cooling, they may become cloudy, but they remain
homogeneous.
Preferably, the components of the mixture containing the
fabric softener, the aminosilicone and the Bronsted acid
are compatible at a silicone concentration of at least
about 2%.
Mutually soluble and clear mixtures of the silicone, the
fabric softening component and the Bronsted acid indicate
the highest degree of compatibility and are preferred.
Mutual solubility of the fabric softening component and
the aminosilicone is achieved by addition of Bronsted
acid.
The amount of the Bronsted acid necessary to
compatibilise the aminosilicone with the fabric softening
component depends on the particular fabric softening
component, the aminosilicone and the amounts of the
fabric softening component and the aminosilicone used.
The appropriate amount of the Bronsted acid is
ascertained by the Compatibility Test.
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The amount of Bronsted acid needed to compatibilise an
aminosilicone with a fabric softening component may be
approximated using a calculation based on amine neutral
equivalent of the aminosilicone. Amine neutral
equivalent (also known as base equivalent) of the
aminosilicone is usually indicated on Material Safety
Data Sheets obtained from the supplier. Using, for
example, "DC X2-8122 (an aminisilicone having 1.2~ X 10 3
equivalents per gram) and stearic acid (having 3. 51 X
10 3 equivalents per gram) the ratio of the aminosilicone
to stearic acid is as follows:
3. 51 X lO 3 eq stearic acid/gram stearic acid
_____________________________________________
1.25 X lO 3 eq aminosilicone/gram aminosilicone
and is equal to 2.79 grams aminosilicone per gram stearic
acid. Preferably, a small excess of the Bronsted acid is
used.
However, it should be understood that the above
calculation based on amine neutral equivalent of the
aminosilicone may be used only as a guideline and the
mutual compatibility among an aminosilicone, a fabric
softener and a Bronsted acid should be ascertained by
checking transparency of the mixture containing these
components. For example, mutual solubility among the
aminosilicone, the fabric softening component and the
Bronsted acid also depends on the particular fabric
softening component. Where the fabric softening
component contains a carboxylic acid the amount of the
Bronsted acid necessary to form the mutually soluble
mixture may be less than the amount obtained from the
above calculation.
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The fabric conditioning compositions of the invention
include a liquid carrier, which is water and which may
additionally contain organic solvents such as lower
alcohols selected from, for example, methyl alcohol,
ethyl alcohol and isopropanol. Both the diluted and the
concentrated versions of the product are preferably
dispersions of the active ingredients in the water
solvent matrix.
The aminosilicone, the fabric softening component and the
Bronsted acid which have been ascertained to form a
mutually soluble mixture are melted usually at
temperatures of less than 100~C for processing
convenience and mixed in any order of addition and the
resulting mutually soluble mixture is dispersed to form
composite particles of the fabric softening component,
the aminosilicone and the Bronsted acid in a liquid
carrier. Of course, the materials can be spray dried to
form discrete softener particles which may also be
dispersed in liquid or other forms of product.
The composite particles typically form about 1% to about
60% of the fabric conditioning composition of the
invention, preferably about 1% to about 30%, and most
preferably about 1% to about 20%. Remaining fabric
softening component, aminosilicone and the Bronsted acid
may be dispersed separately without forming a mutually
soluble mixture.
Various additives may be used in combination with the
composite particles. These include small amounts of
incompatible silicones, such as predominantely linear
polydialkylsiloxanes, e.g. polydimethylsiloxanes; alkyl
quaternary ammonium salts having one C8 30 alkyl chain;
soil release polymers such as block copolymers of
polyethylene oxide and terephthalate; fatty amines
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selected from the group consisting of primary fatty
amines, secondary fatty amines, tertiary fatty amines and
mixtures thereof; amphoteric surfactants; smectite type
inorganic clays; anionic soaps; zwitterionic quaternary
ammonium compounds and nonionic surfactants.
Other optional ingredients include emulsifiers,
electrolytes, optical brightners or fluorescent agents,
buffers, perfumes, colourants, germicides and
bactericides.
An article is disclosed for conditioning fabrics in a
tumble dryer. The articles of the invention comprises a
flexible substrate which carries a fabric conditioning
amount of a conditioning composition and is capable of
releasing the conditioning composition at dryer operating
temperatures. The conditioning composition in turn has a
preferred melting (or softening) point of about 25~C to
about 150~C.
The fabric conditioning composition employed in the
invention is coated onto a dispensing means which
effectively releases the fabric conditioning composition
in a tumble dryer. Such dispensing means can be designed
for single usage or for multiple uses. One such article
comprises a sponge material releasably enclosing enough
of the conditioning composition to effectively impart
fabric softness during several drying cycles. This
multi-use article can be made by filling a porous sponge
with the composition. In use, the composition melts and
leaches out through the pores of the sponge to soften and
condition fabrics. Such a filled sponge can be used to
treat several loads of fabrics in conventional dryers,
and has the advantage that it can remain in the dryer
after use and is not likely to be misplaced or lost.
2 ~
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Another article comprises a cloth or paper bag releasably
enclosing the composition and sealed with a hardened plug
of the mixture. The action and heat of the dryer opens
the bag and releases the composition to perform its
softening.
A highly preferred article comprises the compositions
containing the softener and the compatible silic~ne
releasably affixed to a flexible substrate such as a
sheet of paper or woven or nonwoven cloth substrate.
When such an article is placed in an automatic laundry
dryer, the heat, moisture, distribution forces and
tumbling action of the dryer removes the composition from
the substrate and deposits it on the fabrics.
The sheet conformation has several advantages. For
example, effective amounts of the compositions for use in
conventional dryers can be easily absorbed onto and into
the sheet substrate by a simple dipping or padding
process. Thus, the end user need not measure the amount
of the composition necessary to obtain fabric softness
and other benefits. Additionally, the flat configuration
of the sheet provides a large surface area which results
in efficient release and distribution of the materials
onto fabrics by the tumbling action of the dryer.
The substrates used in the articles can have a dense, or
more preferably, open or porous structure. Examples of
suitable materials which can be used as substrates herein
include paper, woven cloth, and non-woven cloth. The
term 'cloth' herein means a woven or non-woven substrate
for the articles of manufacture, as distinguished from
the term 'fabric' which encompasses the clothing fabrics
being dried in an automatic dryer.
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It is known that most substances are able to absorb a
liquid substance to some degree; however, the term
'absorbent', as used herein, is intended to mean a
substrate with an absorbent capacity (i.e., a parameter
representing a substrate's ability to take up and retain
a liquid) from 4 to 12, preferably 5 to 7 times its
weight of water.
If the substrate is a foamed plastics material, the
absorbent capacity is preferably in the range of 15 to
22, but some special foams can have an absorbent capacity
in the range from 4 to 12.
Determination of absorbent capacity values is made by
using the capacity testing procedures described in U.S.
Federal Specifications (UU-T-595b), modified as follows:
1. tap water is used instead of distilled water;
2. the specimen is immersed for 30 seconds instead of 3
minutes;
3. draining time is 15 seconds instead of 1 minutes;
and
4. the specimen is immediately weighed on a torsion
balance having a pan with turned-up edges.
Absorbent capacity values are then calculated in
accordance with the formula given in said Specification.
Based on this test, one-ply, dense bleached paper (e.g.,
Kraft or bond having a basis weight of about 32 pounds
per 3,000 square feet) has an absorbent capacity of 3.5
to 4; commercially available household one-ply towelling
paper has a value of 5 to 6; and commercially available
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two-ply household towelling paper has a value of 7 to
about 9.5.
Suitable materials which can be used as a substrate in
the invention herein include, among others, sponges,
paper and woven and non-woven cloth, all having the
necessary absorbency requirements defined above.
The preferred non-woven cloth substrates can generally be
defined as adhesively bonded fibrous or filamentous
products having a web or carded fibre structure (where
the fibre strength is suitable to allow carding), or
comprising fibrous mats in which the fibres or filaments
are distributed haphazardly or in random array (i.e. an
array of fibres in a carded web wherein partial
orientation of the fibres is frequently present, as well
as a completely haphazard distributional orientation), or
substantially aligned. The fibres or filaments can be
natural (e.g. wool, silk, jute, hemp, cotton, linen,
sisal or ramie) or synthetic (e.g. rayon, cellulose
ester, polyvinyl derivatives, polyolefins, polyamides or
polyesters).
The preferred absorbent properties are particularly easy
to obtain with non-woven cloths and are provided merely
by building up the thickness of the cloth, i.e., by
superimposing a plurality of carded webs or mats to a
thickness adequate to obtain the necessary absorbent
properties, or by allowing a sufficient thickness of the
fibres to deposit on the screen. Any diameter or denier
of the fibre (generally up to about 10 denier) can be
used, inasmuch as it is the free space between each fibre
that makes the thickness of the cloth directly related to
the absorbent capacity of the cloth, and which, further,
makes the non-woven cloth especially suitable for
- 23 - C6121
impregnation with a composition by means of
intersectional or capillary action. Thus, any thickness
necessary to obtain the required absorbent capacity can
be used.
When the substrate for the composition is a non-woven
cloth made from fibres deposited haphazardly or in random
array on the screen, the articles exhibit excell~nt
strength in all directions and are not prone to tear or
separate when used in the automatic clothes dryer.
Preferably, the non-woven cloth is water-laid or air-laid
and is made from cellulosic fibres, particularly from
regenerated cellulose or rayon. Such non-woven cloth can
be lubricated with any standard textile lubricant.
Preferably, the fibres are from 5mm to 50mm in length and
are from 1.5 to 5 denier. Preferably, the fibres are at
least partially oriented haphazardly, and are adhesively
bonded together with a hydrophobic or substantially
hydrophobic binder-resin. Preferably, the cloth
comprises about 70% fibre and 30% binder resin polymer by
weight and has a basis weight of from about 18 to 45g per
square meter.
In applying the fabric conditioning composition the the
absorbent substrate, the amount impregnated into and/or
coated onto the absorbent substrate is conveniently in
the weight ratio range of from about 10:1 to 0.5:1 based
on the ratio of total conditioning composition to dry,
untreated substrate (fibre plus binder). Preferably, the
amount of the conditioning composition ranges from about
5:1 to about 1:1, most preferably from about 3:1 to 1:1,
by weight of the dry, untreated substrate.
2~.3~ 7~
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According to one preferred embodiment of the invention,
the dryer sheet substrate is coated by being passed over
a rotogravure applicator roll. In its passage over this
roll, the sheet is coated with a thin, uniform layer of
molten fabric softening compositon contained in a
rectangular pan at a level of about 15g/square yard.
Passage of the substrate over a cooling roll then
solidifies the molten softening composition to a solid.
This type of application is used to obtain a uniform
homogeneous coating across the sheet.
Following application of the liquefied composition, the
articles are held at room temperature until the
composition substantially solidifies. The resulting dry
articles, prepared at the composition substrate ratios
set forth above, remain flexible; the sheet articles are
suitable for packaging in rolls. The sheet articles can
optionally be slitted or punched to provide a
non-blocking aspect at any convenient time if desired
during the manufacturing process.
The amount of the fabric softening composition on the
sheet is subject to normal coating parameters such as,
for example, viscosity and melting point of the fabric
softening component and is typically about 0.5 grams to
about 5 grams, preferably about 1 gram to about 3.5
grams. The fabric softening composition employed in the
present invention contains about 0.1% to about 95% of the
fabric softening component. Preferably from about 10% to
about 80% and most preferably from about 30% to about 70%
of the fabric softening component is employed herein to
obtain optimum softening at minimum cost. When the
fabric softening component includes a quaternary ammonium
salt, the salt is used in the amount of about 10% to
about 80%, preferably about 30% to about 70%.
2~ 3 '~
- 25 - C6121
The fabric conditioning compositions of the invention can
be used in the rinse cycle of a conventional home laundry
operation. Generally, rinse water has a temperature of
from about 5~C to about 70~C. The concentration of the
total active ingredients is generally from about 2 ppm to
about 1000 ppm, preferably from about 10 ppm to about 500
ppm, by weight of the aqueous rinsing bath. When
multiple rinses are used, the fabric conditionin~
compositions are preferably added to the final rinse.
The following Examples will more fully illustrate the
embodiments of this invention. All parts, percentages
and proportions referred to herein and in the appended
claims are by weight of the composition unless otherwise
indicated.
CA 02043470 1997-11-13
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Example I
Compatibilising effect of stearic acid in fabric
softening mixtures containing an aminosilicone and fabric
softeners was investigated.
Compatibilised aminosilicone was prepared by blending 3.7
grams of the aminosilicone (Silicone SL) with 1.3_grams
of molten stearic acid (*Hydrofol Acid 1895). Various
fabric softener actives as indicated in Table I were then
added to the resulting compatibilised silicone with
stirring and sufficient heat to melt all the components.
Results that were generated are summarised in Table I.
TableI
Fabric Softener Mutual Solubility of Fabric
Softener With
Silicone SL Compatibilised
Silicone SL
Mineral Oil (Fisher) no yes
~Adogen 442 no yes
Adogen 343 no yes
lAdogen 442 = dihydrogenated tallow dimethylammonium
chloride from Sherex Corp.
2Adogen 343 = dihydrogenated tallow methyl amine from
Sherex Corp. Adogen 442 was mutually soluble with
compatibilised Silicone SL (Silicone SL mixed with
stearic acid) up to about 30~ of Adogen 442.
Adogen 343 was mutually soluble with the compatibilised
silicone up to about 25~ of Adogen 343.
~denotes trade mark
- 27 - C6121
Changing the order of addition did not influence the
compatibilising effect of stearic acid.
This example demonstrates that addition of stearic acid,
which is a Bronsted acid within the scope of the
invention compatibilises aminosilicones with various
fabric softeners.
CA 02043470 l997-ll-l3
- 28 - C6121
Example II
Compatibilising effect of Bronsted acids in fabric
softening mixtures containing an aminosilicone and
mineral oil was studied. Results that were generated are
summarised in Table I.
Table I .
Weight (grams)
Components Sample IA IB IC ID
Mineral oil1 10 5.0 50 50
Aminosilicone2 0.2 4.40100 100
Hexanoic Acid - 0. 61 - -
Hydrochloric Acid - - 4.6
Acetic Acid - - - 7.58
Fisher Light Mineral Oil
Silicone SL
"3Aldrich Gold Label
Sample IA was observed to be opaque at the aminosilicone
concentration of 2% by weight of the mixture, while
Sample IB remained transparent at the aminosilicone
concentration of 44~. Samples IC and ID were opaque and
phase separation was observed indicating that the
mixtures of these samples were incompatible.
This example demonstrates that hexanoic acid, which is a
Bronsted acid within the scope of the invention,
compatibilises the aminosilicone with mineral oil in the
fabric softening mixtures. The compatibilising effect
was not observed inthe absence of hexanoic acid.
~denotes trade mark
- 29 - C6121
Hydrochloric acid and acetic acid, which are not Bronsted
acids within the scopeof the present invention, did not
have a compatibilising effect in mixtures of mineral oil
with aminosilicone.
CA 02043470 l997-ll-l3
- 30 - C6121
Example III
Compatibilising effect of stearic acid in fabric
softening mixtures containing an aminosilicone and
quaternary ammonium salts was studied. The amount of
stearic acid necessary to compatibilise an aminosilicone
with a fabric softening agents approximated using an
amine neutral equivalent. _
The results that were obtained are summarised in Table I.
Table I
Components Weight (grams)
Sample 1 2 3 4
Aminosilicone0.22.5 0.1 2.5
Adogen 3431 lO lO
*Varisoft 1372 _ lo lo
Stearic acid - 0.89 - 0.89
lAdogen 343 = dihydrogenated tallow methyl amine from
Sherex Corp.
2Varisoft 137 = dihydrogenated tallow dimethyl ammonium
methylsulfate from Sherex Corp.
Observations:
Samples 1 and 3 were incompatible as determined by the
Compatibility Test at aminosilicone concentration of 2%
and 1% respectively. Samples 2 and 4 were compatible as
determined by the Compatibility Test at 25% silicone
concentration.
*denotes trade mark
2~ 3iJ~ ~ ~
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- 31 - C6121
This example demonstrates that stearic acid, a Bronsted
acid within the scope of the invention, compatibilises
aminosilicones with fabric softening agents as determined
by the Compatibility Test.
- 32 - ~C612
Example IV
Example IVA:
3 g of dihydrogenated tallow dimethylammonium chloride
(Adogen 442) was added to 5 g mineral oil, 3.7 g Silicone
SL, and 1.3 g Hydrofol Acid 1895 (stearic acid) with
stirring and heating. The resulting mixture was..a clear,
homogeneous, one-phase system.
Example IV:
A 5% aqueous dispersion of composition particles
containing the mutually soluble mixture of Example IVA
was then prepared by adding the mutually soluble mixture
to water, with heating to liquify the solids, and
stirring with an overhead stirrer. Stirring was
maintained while the dispersion was cooled to room
temperature. Additional particle size reduction was
achieved by passing it through a Gaulin homogeniser at
6000 PSI.
Example IVC:
A series of fabric conditioning formulations was prepared
by blending the dispersion prepared in Example IVB with
10% emulsion of polydimethylsiloxane containing 5% Adogen
442 based on silicone weight. The samples in this series
contained 5%, 10%, 20%, 30%, 40%, and 50% of the
dispersion of Example IIB.
Example IVD:
A series of fabric conditioning formulations was prepared
by blending the dispersion prepared in Example IVB with
2 ~ O
_ 33 _ C6121
35% emulsion of Silicone SL containing 2% Adogen 442
based on silicone weight. The samples in this series
contained 5%, 10%, 20%, 30%, 40% and 50% of the
dispersion of Example IVB.
This example demonstrates that addition of stearic acid,
which is a Bronsted acid within the scope of the
invention, compatibilises an aminosilicone with a
cationic fabric softener.
The example further illustrates that a liquid fabric
softening composition containing composite particles of
the mutually soluble mixture of the aminosilicone, the
fabric softener and the Bronsted acid within the scope of
the invention can be prepared and can be incorporated
with other fabric treating ingredients.
Example V
Fabric softening formulations incorporating composite
particles of the invention were prepared as summarised in
Table II. Samples A, B, C and D contain composite
particles of aminosilicone (Silicone SL), stearic acid,
mineral oil and Adogen 442. Sample A was prepared in
Example IIB.
Sample B is a dispersion prepared in the same manner as
sample A, but contains 10.0 g of mineral oil instead of
5g of mineral oil in sample A.
Sample C is a 1:1 blend of sample A with S% dispersion of
Adogen 442, also containing 15 ppm NaCl.
Sample D is a 1:1 blend of sample A with 5% dispersion of
Varisoft 445 (methyl-1-hydrogenated tallow
CA 02043470 1997-11-13
- 34 - C6121
amidoethyl-2-hydrogenated tallow imidazolinium methyl
sulfate from Sherex Corp.). also containing 15 ppm CaCl2.
Table II
Liquid Fabric Conditioninq Rinse Compositions
Ingredients Sample A B C D
Adogen 442 1.15 0.83 2.92 0.42
Varisoft 445 - - - 2.50
Mineral Oil 1.92 2.78 1.39 1.39
Silicone SL 1.41 1.02 0.50 0.50
Stearic Acid 0.52 0.37 0.19 0.19
NaCl - - tr.
CaC12 - - - tr.
Perfume - - tr. tr.
Colourant - - tr. tr.
Preservative - - tr. tr.
Water ---------to 100%----------
Samples A, B, C and D from Table II were evaluated for
their softening properties. Terry cloths were prewashed
with a solution of ~Neodol 25-9 (ethoxylated alcohol from
Shell Corp.) and Na2CO3 to remove textile finishes on the
surface, rinsed with the samples in a Tergometer and then
line dried. The cloth load was 35 g per litre of water.
The concentration of composite particles was 0.1 g per
litre of water. The concentration of composite particles
was 0.1 g per litre of water. The control samples were
rinsed in water only. For both the experimental and
control samples, water hardness of 120 ppm was used.
Using paired comparisons, a panel of 20 judges assessed
the softness of the treated cloths vs. controls. All
~denotes trade mark
2~ a
- 35 - C6121
panelists preferred the treated cloths over the controls
in all evaluations.
Example VI
The ability of Bronsted acids to compatibilise
amine-functional silicones with mineral oil was
investigated.
Example VIA:
lOg of mineral oil (Fischer Heavy Mineral Oil) was placed
in a vial. 3g of an aminosilicone (Silicone SL) was
added with stirring. The resulting mixture was an opaque
emulsion which completely separated on standing in an
oven at 80~C for 1 hour.
Example VIB
A series of vials were prepared all containing 10g
mineral oil + 3g Silicone SL and increasing amounts of
stearic acid (Sherex Hydrofol Acid 1985). When the
amount of acid was 1.5g or higher and the temperature was
above the melting point of the acid, a clear, stable
solution formed, which did not separate into different
phases on standing at elevated temperatures. Upon
cooling to room temperature, the compatibilised mixtures
remained single phase. Varying the order of addition of
the components did not change the outcome of the
experiments.
Based on an amine neutral equivalent calculation, the
amount of stearic acid necessary to compatibilise 3g of
DC X2-8122 is l.lg.
3 ~
- 36 - C6121
Example VIC:
lOg of a fabric softener which is a mixture of
dihydrogenated tallow-di-methyl ammonium methylsulfate
(70%) and C14-C18 fatty acids (30% was place in a small
vial and melted with stirring. Silicone SL (an
aminosilicone) was added to produce a mixture which is
25% silicone by weight (3.33 g of silicone). The_
resulting mixture was opaque but stable as determined by
the Compatibility Test.
Based on amine neutral equivalent calculation, the amount
of stearic acid necessary to compatibilise 3.3g of DC
X2-8122 is 1.2g. However, the fabric softener already
contained 3g of fatty acids. Thus, it was not necessary
to admix additional Bronsted acid to attain the
compatible mixture of Example VIC.
This example demonstrates that stearic acid, a Bronsted
acid within the scope of the invention, compatibilised an
aminosilicone with a fabric softener (Example VIB).
Aminosilicone was not compatible with a fabric softener
in the absence of a Bronsted acid (Example VIA).
The example further demonstrates that the amount of
Bronsted acid necessary to compatibilise an aminosilicone
with a fabric softening component must be ascertained
using the Compatibility Test and the amount based on
amine neutral equivalent calculation can be used only as
a guideline.
2 ~
_ 37 _ C6121
Example VII
The ability of Bronsted acids to compatibilise
aminosilicones with nonionic fabric softeners was
investigated.
8g of Span 60 (a mixture of sorbitan monostearate and
isosorbide esters with about 3% fatty acid) was placed in
each of several vials. To the vials was added 3g of
Silicone SL and increasing amounts of stearic acid
(Sherex Hydrofol Acid 1895). When the amount of acid
exceeded 0.5g, the mixture formed a clear, stable
solution.
Based on amine neutral equivalent calculation, the amount
of stearic acid necessary to compatibilise 3g of DC
X2-8122 is l.lg.
This example demonstrates that an aminosilicone is
compatibilised with a nonioinc fabric softener by
addition of stearic acid.
The example further demonstrates that the amount of
Bronsted acid necessary to compatibilise an aminosilicone
with a fabric softening component must be ascertained
using the compatibility test and the amount based on
amine neutral equivalent calculation can be used only as
a guideline. Thus, when a fabric softening component
contains fatty acid, the amount of Bronsted acid
necessary to compatibilise silicone is typically less
than the amount based on amine neutral equivalent
calculation.
~Q~3~7~ Q
-
- 38 - C6121
Example VIII
Compatibilising effect of alkylbenzene sulfonic acid in
fabric softening mixtures containing an aminosilicone and
nonionic fabric softener was studied.
lOg mineral oil was combined with 3g Silicone SL and 2g
of a linear alkylbenzene sulfonic acid having ll.carbon
alkyl chain. The mixture was stirred at room temperature
and formed a clear, stable mixture which did not separate
on standing.
This example demonstrates that an aminosilicone is
compatibilised with a nonionic fabric softener by
addition of alkylbenzene sulfonic acid.
Example IX
Compatible fabric conditioning mixture were prepared.
Di(hydrogenated tallow)-di-methyl ammonium methyl sulfate
(Varisoft 137 from Sherex Corp.) was combined with
commercially available aminosilicones and other softeners
in various proportions as indicated in Table II.
The mixtures were all found to be homogeneous and stable
at processing and use temperatures.
2~3'~7~
- 39 - C6121
Table II
Weight percent of formulation
Code Varisoft 137 Stearic Acid Silicone Magnasoft Span
SL Ultra60
A 70 10 - 20
B 70 10 2 - -
C 23 7 20 - 50
D 70 20 - 10
E 70 20 10
Formulation E from Table II above was fabricated into an
article for use in the tumble dryer by coating the molten
composition onto sheets of spun bonded polyester using a
two roll coating machine.
The article with the solidified softening composition was
placed in a tumble dryer with freshly laundered clothing
and the dryer was operated in the normal fashion for one
hour. Upon removal, the clothing was judged to have
excellent antistatic properties. The weight loss of the
softening article was assessed and it was judged that the
softening composition transferred to the clothing in the
environment of the dryer. A 20 member employee panel
then judged the clothing to have superior softness when
compared to control samples without softner in a pair
comparison test.
This invention has been described with respect to certain
preferred embodiments and various modifications thereof
will occur to persons skilled in the art in the light of
the instant specification and are to be included within
2 ~ .f~ O
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- 40 - C6121
the spirit and purview of this application and the scope
of the appended claims.
