[0001] This invention relates to fabric softening products for applications to laundry during
washing and/or, rinsing cycles, to apply to the fibers of the fabrics of such laundry
fabric softening amounts of fabric softening compounds of such products. More particularly,
it relates to such products that include as fabric softening components higher fatty
acid esters of pentaerythritol, of pentaerythritol oligomers, or of ethoxylated derivatives
of such pentaerythritol or oligomer esters, and any mixtures thereof, all of which
may be designated PEC (for pentaerythritol compound), together with a clay of the
montmorillonite type, very preferably bentonite, and which do not necessarily contain
quaternary ammonium salts.
[0002] Fabric softening compositions and articles have long been employed to make washed
laundry items softer to the touch and more comfortable to the wearer. Such compositions
include solutions, emulsions and particulate and powder products. The fabric softeners
of choice for most commercial products have usually been quaternary ammonium salts,
such as dimethyl ditallowyl ammonium chloride, and emulsions of such softener have
been added to the rinse water in the washing machine to soften laundry. Alternatively,
such emulsions or powder products including such fabric softener can be added to the
wash water, with a detergent composition, or the detergent composition can include
a fabric softening components, making it a so-called "softergent".
[0003] Although various fabric softening (and antistatic) compositions, including softergents,
have been marketed over the years, with varying degrees of commercial success, and
although different fabric softening compounds have been included in them, the most
successful of such compounds have been quaternary ammonium salts. Such compounds are
often of the formula

wherein R, R', R" and R"' are all alkyl groups, with at least one of such alkyls
being a higher alkyl (of 8 to 22 or 24 or of 12 to 18 carbon atoms) and with the others
being lower alkyl(s) of 1 or 2 carbon atoms, and with X
- being a salt-forming anion. Preferably, such quaternary ammonium salt is a di-lower
alkyl, di-higher alkyl ammonium halide but mono-lower alkyl tri-higher alkyl ammonium
halides have also found use in some instances.
[0004] While such quaternary ammonium salts have been effective fabric softeners in the
described applications they are characterised by disadvantageous properties too, which
have led to attempts to find replacements for them. For example, being cationic, they
tend to react with anionic materials, such as anionic synthetic organic detergents
and builders for synthetic detergents, sometimes to the detriment of their intended
fabric softening function. They can deposit on laundry in such manner as to appear
as greasy spots, which are highly objectionable. Finally, and perhaps most important,
they are not as readily biodegradable as is desirable and they have been found to
be toxic to aquatic organisms, which could lead to harmful effects on aquatic life
in lakes, rivers and other waters into which waste waters carrying such compounds
could eventually be emptied.
[0005] EP-A-494769 is citable under EPC Article 54(3). It discloses a dispersion in water
of 20 parts clay (gel forming sodium bentonite), 2 parts tripentaerythritol tetralaurate,
2 parts optional emulsifier and 76 parts water.
[0006] In efforts to find a replacement for quaternary ammonium salts as fabric softeners,
neoalkanamides, glyceryl esters, glycol esters, silicones, cationic-anionic complexes,
bentonite and various lubricants have been suggested for use alone or in conjunction
with reduced amounts of the quaternary ammonium salts but frequently the softening
effects thereof were insufficient or the replacement softeners possessed other characteristics
which made them even less desirable than the quaternary ammonium salts. Now, however,
applicants have discovered that the PECs described herein, including the oligomers
and lower alkoxylated derivatives, when employed in conjunction with a montmorillonite
clay, such as a swellable bentonite, can satisfactorily soften laundry essentially
to the same extent as the quaternary ammonium salts, and they don't exhibit the adverse
effects of the quaternary ammonium salts on aquatic organisms. This is an especially
important discovery at this time, when the seriousness of the problem is being recognised
and when several countries are passing laws and promulgating regulations prohibiting
the incorporation of quaternary ammonium compounds (hereafter "quats") in products
that can be discharged into sewage and drainage systems. The invented compositions
are surprisingly effective softergents, which clean as well as detergent compositions
based on the same detersive components, and they also act synergistically with respect
to fabric softening in non-detersive products such as wash cycle and rinse additives,
and dryer products, in all of which the combination of PEC and bentonite softens treated
laundry significantly better than would be expected from the additive effective of
such components. Moreover, whereas fabric softenings by each of the PEC and bentonite
asymptotically approach limits which are below the excellent softening that is desirable,
a composition containing PEC and bentonite softens significantly better and transcends
such limits.
[0007] In accordance with the present invention a particulate fabric softening detergent
composition for application to fibrous materials, so that a fabric softening component
thereof is deposited on the fibrous materials and softens them, comprises a PEC, which
is a fabric softening component which is a C
8-C
24 aliphatic acid ester of pentaerythritol, of an oligomer of pentaerythritol, of a
lower alkylene oxide derivative, containing 1 to 10 alkylene oxide moieties, of pentaerythritol
or of a lower alkylene oxide derivative, containing 1 to 10 alkylene oxide moieties,
of an oligomer of pentaerythritol, or a mixture thereof, a montmorillonite clay capable
of swelling in use, and a synthetic organic detergent of the anionic and/or nonionic
type(s) the composition containing 1 to 35% by weight of the detergent, 2 to 20% by
weight of the PEC and 10 to 30% by weight of the clay.
[0008] The particulate composition preferably contains 2 to 15% of PEC and 10 to 25% of
bentonite.
[0009] The synthetic organic detergent is preferably a mixture of anionic and nonionic detergents,
and the proportion thereof is in the range of 3 to 25%, the composition is built with
10 to 60% of builder, and the proportions of PEC and bentonite are in the ranges of
2 to 15% and 10 to 25%.
[0010] The anionic detergent may be a sulfated and/or sulfonated detergent, the nonionic
detergent may be a condensation product of a higher fatty alcohol and ethylene oxide,
the builder may be selected from the group consisting of water soluble alkali metal
polyphosphates, carbonates, silicates, borates, citrates, bicarbonates, gluconates,
nitrilotriacetates and ethylene diamine tetraacetates, water insoluble water softening
zeolites, and mixtures thereof, the PEC may be a higher aliphatic acid partial ester
of pentaerythritol or of an oligomer of pentaerythritol, and the bentonite may be
sodium and/or calcium bentonite.
[0011] A preferred particulate composition in accordance with the invention comprises 1
to 10% of sodium higher alkylbenzene sulfonate, 1 to 10% of nonionic detergent, which
is a condensation product of one mol of higher fatty alcohol and 5 to 10 mols of ethylene
oxide, 2 to 10% of sodium silicate, 15 to 35% of sodium tripolyphosphate, 2 to 10%
of sodium carbonate, 3 to 10% of higher aliphatic acid partial ester of pentaerythritol
and 12 to 20% of sodium and/or calcium bentonite.
[0012] The higher aliphatic acid partial ester of pentaerythritol is preferably pentaerythritol
distearate and the bentonite is preferably calcium bentonite.
[0013] In another form of the invention the composition is provided in liquid or gel form
which comprises 3 to 20% of the synthetic organic detergent, 2 to 20% of the PEC and
10 to 30% of the bentonite, in an aqueous medium.
[0014] The compositions in accordance with the present invention are preferably essentially
free of quaternary ammonium compound fabric softener.
[0015] Of the PECs those which are preferred are the pentaerythritol distearates and dipentaerythritol
dilaurates, and of the montmorillonites, sodium and calcium bentonite are preferred.
The invention also includes processes for softening laundry with the invented products.
[0016] A search of prior art relevant to the invention has resulted in the finding of the
following:
U.S. Patents 3,928,212; 4,126,562; 4,142,978; 4,162,984; and 4,214,038;
European Patent Application 276999-A;
German Patent Application 3612479-A; and
Japanese Patent 90 47,370.
[0017] U.S. patent 3,928,212 describes various softening agents which are polyhydric alcohol
esters but none of them is a pentaerythritol ester or an ester of an oligomer or ethoxylated
derivative of pentaerythritol or of an oligomer thereof. U.S. 4,126,562 mentions erythritol
and pentaerythritol in a list of alcohols which may be reacted with higher fatty acids
to produce fabric conditioning agents but no such compound is actually described and
none is shown in a fabric softening composition or article. Also U.S. patent 4,126,562
is for a combination of a quaternary ammonium salt fabric softener and a nonionic
ester of an alcohol with a higher fatty acid, and there is no teaching that the ester
would be useful alone as a fabric softener. U.S. patent 4,142,978 describes sorbitan
esters with phase modifying components, such as alkyl sulfates, on a dryer sheet for
softening laundry while it is being tumble dried in an automatic laundry dryer. The
patent does not mention any pentaerythritol esters. U.S. patent 4,162,984 relates
to a textile treatment emulsion of a water insoluble cationic fabric softener, which
is preferably a quaternary ammonium salt or an alkylimidazolinium salt, with a water
insoluble nonionic fabric softener, which is preferably a fatty acid ester of a mono-
or polyhydric alcohol or an anhydride thereof, and an aromatic mono-or dicarboxylic
acid. Among the polyhydric alcohols that may be esterified, according to the patent,
is pentaerythritol, but no pentaerythritol ester is described specifically nor is
any oligomer of pentaerythritol suggested, and none is shown to be a useful fabric
softening agent in the absence of quaternary ammonium salt and aromatic carboxylic
acid. It is clear that the patentees did not know of the present invention because
they were aware of the disadvantages of the quaternary ammonium salt component (reaction
with anionic detergent from the wash cycle) and found that its content could be reduced
if the pentaerythritol ester and aromatic carboxylic acid were present, but they never
recognised and apparently never made a fabric softening composition which did not
contain quaternary ammonium halide or equivalent fabric softener. U.S. patent 4,214,038
relates to polyglycerol esters as softening agents suitable for deposition on drying
laundry from paper substrates charged to the laundry dryer with the laundry being
dried. Although polyglycerol is a polyhydric alcohol, as is pentaerythritol, it is
not the same as pentaerythritol and the patent does not suggest the use of applicants'
pentaerythritol esters as fabric softeners. European patent specification 276999-A
mentions fabric conditioning compositions that contain a non-cationic fabric softener
and a nonionic cellulose ether. Although ester of polyhydric alcohols are mentioned
as suitable conditioning agents, pentaerythritol esters are not disclosed. German
patent specification 3612479-A describes textile softening compositions that contain
quaternary ammonium compounds with carboxylic acid esters, and among the esters are
those of various alcohols and polyols, including pentaerythritol. However, no such
specific ester is described or even named, and no softening composition which does
not contain quaternary ammonium compound as the fabric softener is disclosed. Japanese
patent 90 47,370 discloses fabric softening compositions that are based on quaternary
ammonium salts but may contain a higher fatty acid ester of pentaerythritol. No specific
such ester is described in the abstract.
[0018] In none of the disclosures mentioned above is it taught that any pentaerythritol
ester could be employed with a montmorillonite clay, such as bentonite, as a fabric
softening combination, in place of a quaternary ammonium compound or quat softener
and would have essentially as good or better a softening action, and none of the disclosures
mentions any specific pentaerythritol ester nor does any mention an ester of an oligomer
of pentaerythritol, of lower alkoxylated pentaerythritol or of an oligomer thereof
as a fabric softening agent in a fabric softening composition. Thus, none of the references,
either alone or in combination with any of the others, anticipates the present invention
or makes it obvious.
[0019] A main component of the invented compositions of the present invention, which is
usually the main fabric softening compound in such products, other than the fabric
softening clay, such as bentonite, which will also be present in them, is a higher
fatty acid ester of a pentaerythritol compound, which term is used in this specification
to described higher fatty acid esters of pentaerythritol, higher fatty acid esters
of pentaerythritol oligomers, higher fatty acid esters of lower alkylene oxide derivatives
of pentaerythritol and higher fatty acid esters of lower alkylene oxide derivatives
of pentaerythritol oligomers. Pentaerythritol compound may be abbreviated as PEC herein,
which description and abbreviation may apply to any or all of pentaerythritol, oligomers,
thereof and alkoxylated derivatives thereof, as such, or more preferably and more
usually, as the esters, as may be indicated by the context.
[0020] The oligomers of pentaerythritol are preferably those of two to five pentaerythritol
moieties, more preferably 2 or 3, with such moieties being joined together through
etheric bonds. The lower alkylene oxide derivatives thereof are preferably of ethylene
oxide or propylene oxide monomers, dimers or polymers, which terminate in hydroxyls
and are joined to the pentaerythritol or oligomer of pentaerythritol through etheric
linkages. Preferably there will be one to ten alkylene oxide moieties in each such
alkylene oxide chain, more preferably 2 to 6, and there will be one to ten such groups
on a PEC, depending on the oligomer. At least one of the PEC OH groups and preferably
at least two, e.g., 1 or 2 to 4, are esterified by a higher fatty acid or other higher
aliphatic acid, which can be of an odd number of carbon atoms.
[0021] The higher fatty acid esters of the pentaerythritol compounds are preferably partial
esters and more preferably there will be at least two free hydroxyls thereon after
esterification (on the pentaerythritol, oligomer or alkoxyalkane groups). Frequently
the number of such free hydroxyls is two or about two but sometimes it may be one,
as in pentaerythritol tristearate, or as many as eight, as in pentapentaerythritol
tetrapalmitate.
[0022] The higher aliphatic or fatty acids that are employed as esterifying acids are those
of carbon atom contents in the range of 8 to 24, preferably 12 to 22 and more preferably
12 to 18, e.g., lauric, myristic, palmitate, oleic, stearic and behenic acids. Such
may be mixtures of such fatty acids, obtained from natural sources, such as tallow
or coconut oil, or from such natural materials that have been hydrogenated. Synthetic
acids of odd or even numbers of carbon atoms may also be employed. Of the fatty acids
lauric and stearic acids are often preferred, and such preference may depend on the
pentaerythritol compound being esterified.
[0024] The PECs utilised in this invention can have fabric softening effects but such activities
are remarkably increased when a montmorillonite clay (bentonite) is also present.
In the absence of such bentonite the PEC may be substantially undispersed in wash
and rinse waters, and may be less evenly and less strongly applied to laundry from
softening articles. It has been found that better dispersed PEC has greater softening
activity. When undispersed the PEC could be in solid agglomerate form when cold or
in molten form when hot, in neither of which states does it act as effectively to
soften fabrics (and in both of which cases it can deposit objectionably on treated
materials to produce somewhat greasy spotting thereof). The bentonite acts to disperse
the PEC to make it more effective as a softener, and at the same time such "dispersing
agent" also acts as a softener, which avoids the undersirable dilution of softening
action by an ordinary dispersing agent, and it synergistically improves fabric softening.
[0025] The clays that are useful components of the invented products are those which cooperate
synergistically with the PECs to soften laundry better than would be expected from
such a combination. Such clays are the montmorillonite-containing clays which have
swelling properties (in water) and which are of smectite structure, so that they deposit
on fibrous materials, especially cotton and cotton/synthetic blends, such as cotton/polyester,
to give such fibers and fabrics made from them a surface lubricity or softness. The
best of these clays for use in the present invention is bentonite and the best of
the bentonites are those which have a substantial swelling capability in water, such
as the sodium and potassium bentonites. Such swelling bentonites are also known as
western or Wyoming bentonites, which are essentially sodium bentonite. Other bentonites,
such as calcium bentonite, are normally non-swelling and usually are, in themselves,
unacceptable as fabric softening agents. However, the present inventors have found
that such non-swelling bentonites exhibit even better fabric softening in combination
with PECs than do the swelling bentonites, provided that there is present in the composition
being tested for softness, a source of alkali metal or other solubilising ion, such
as sodium (which may come from sodium hydroxide, added to the composition, or from
sodium salts, such as builders and fillers, which may be functional components of
the compositions). This utility of the normally non-swelling bentonite is surprising
and the superiority of such in the invented compositions (when a source of sodium
is present) over normally swelling bentonite, such as sodium bentonite, is very surprising.
Among the preferred bentonites are those of sodium and potassium, which are normally
swelling, and calcium and magnesium, which are normally non-swelling. Of these it
is preferred to utilise calcium (with a source of sodium being present) and sodium
bentonites. The bentonites employed are not limited to those produced in the United
States of America, such as Wyoming bentonite, but also may be obtained from Europe,
including Italy and Spain, as calcium bentonite, which may be converted to sodium
bentonite by treatment with sodium carbonate, or may be employed as calcium bentonite.
Also, other montmorillonite-containing smectite clays of properties like those of
the bentonites described may be substituted in whole or in part for the bentonites
described herein and similar fabric softening results will be obtained.
[0026] The swellable bentonite and similarly operative clays are of ultimate particle sizes
in the micron range, e.g. 0.01 to 20 microns and of actual particle sizes in the range
of Nos. 100 to 400 sieves (which have openings 0.149 to 0.037 mm across), preferably
140 to 325 sieves (which have openings 0.105 to 0.044 mm across), U.S. Sieve Series.
Such size ranges also apply to the zeolite builders, which will be described later
herein. The bentonite and other such suitable swellable clays may be agglomerated
to large particle sizes too, such as 60 to 120 sieves (which have openings 0.25 to
0.125 mm across), but such agglomerates are not preferred unless they include the
PEC(s) too (in any particulate products).
[0027] Liquid state preparations of this invention may be emulsions (which term herein is
also intended to refer to dispersions and suspensions in liquid media, as well as
to emulsions), and any such "emulsions" will normally be aqueous emulsions in which
the aqueous phase is the continuous phase. However, solvents and cosolvents, such
as ethanol, isopropanol, propylene glycol and various mono- and di-lower alkyl esters
of diethylene glycol (Carbitols ®) may also be present in such emulsions and microemulsions
to promote formations of more stable products, and may also be in the continuous media.
Suitable dispersing agents, such as emulsifiers, can be employed with the mentioned
clay to further help it to disperse the PEC in aqueous media. Such as useful in liquid
and solid (including particulate) products.
[0028] Various emulsifiers can be employed , and many such are described in the various
Detergents and Emulsifiers publications of John W. McCutcheon, issued annually, particularly those for 1969,
1973, 1980 and 1981. Preferred such emulsifiers are those which are alkyl ethers or
amines which contain one or more hydroalkyl substituents too. Of these the more preferred
are the alkyl dialkanolamines or alkyl trialkanolpropylenediamines wherein the alkanol
moieties are of 2 to 4 carbon atoms, preferably being 2 to 4 carbon atoms, preferably
2 or 3 and more preferably being 2, and the alkyl poly(ethylene oxide) ethers are
of 2 to 24 ethylene oxide units, preferably of 8 to 12 ethylene oxide units, in which
emulsifiers the alkyl is of 8 to 24, preferably 12 to 18 carbon atoms. More preferred
such emulsifiers are: stearyl diethanolamine, available from Hoechst A.G. as Genamin®
S-020; tallow triethanol propylenediamine, available from CECA, S.A. as Dinoramox®
S3; and R-O-(CH
2CH
2O)
10H, wherein R is a mixture of C
12-15alkyls, available from Hoechst A.G. as Genapol® OH-100.
[0029] When instead of emulsion form for the invented compositions it is desired that they
be in particulate, powder, solid or gel form less water or moisture or even none is
present but the bentonite will still usually be of small (micron range) ultimate size.
Instead of or in addition to the bentonite there may be present other swellable montmorillonite
clays and there may also be present with the bentonite other non-functional substantially
water insoluble carriers or dispersing agents, such as calcium carbonate and silica.
Even water soluble carriers, such as sodium sulfate and other "filler salts" may be
used, at least in part, and such can sometimes act as dispersing agents, too. The
bentonite employed should desirably be of a type which is gel forming in water and
capable of softening fibrous materials, and should be of micron range ultimate particle
size, although it may be agglomerated to larger sizes, usually in the range of 8 to
140 sieves, U.S. Sieve Series (which have openings 2.38 to 0.105 mm across).
[0030] Normally, in the various applications mentioned, the PEC will be employed without
the presence of any other fabric softening material (except the clay, such as bentonite,
montmorillonite or other operative smectite) but it is possible to utilise such other
materials with it if in the proportions and quantities employed they are not ecologically
unacceptable and if they do not interfere with the fiber softening action of the PEC.
In fact, sometimes, when antistatic action is desirable in the product, such additions
may be important because although PECs have some antistatic properties sometimes those
are insufficient for the intended purposes. Thus, it is possible to formulate fabric
softening compositions and articles with the PEC supplemented by other antistatic
agents and also by fabric softeners. The foremost of such antistatic materials are
the quaternary ammonium salts but when they are present there can be ecological problems,
due to their toxicities to aquatic organisms. For example, in standard toxicity tests
against daphnia the concentration for 50% effect is less than 1 mg/l for quaternary
ammonium compounds or quats, such as ditallowalkyl dimethyl ammonium chloride, and
that it is often unacceptable, environmentally, so in such circumstances quats are
not employed. Other antistats and fabric softeners include higher alkyl neoalkanamides,
e.g., N-stearyl neodecanamide; isostearamides; amines, such as N,N-ditallowalkyl N-methyl
amine; esterified quaternary salts or esterquats; amidoamines; amidoquats; imidazolines;
imidazolinium salts; di-higher fatty acid esters of di-lower alkanolamines, such as
dicoco acid ester of diethanolamine; silicones; and alkoxylated silicones; and representative
examples of some of such classes of such compounds are given below (those which may
cause significant ecological harm will desirably be avoided).

CLAY
[0031] = Bentonite
It should be kept in mind when employing supplementary antistats and fabric softeners
that they shouldn't make the compositions in which they are incorporated of greater
ecotoxicity than is allowable by law and by regulatory authorities in the area of
intended use. Thus, quaternary ammonium compounds will usually be avoided, as will
be compounds that have similar adverse effects on aquatic organisms, or the amounts
thereof present will be limited so as to avoid such undesirable effects.
[0032] Other materials that may be incorporated in the invented compositions include the
usual adjuvants that normally are present in other fabric softening compositions (including
softergents), such as perfumes, fixatives, solvents, cosolvents, hydrotropes, antioxidants,
stabilisers, pH adjusters, buffers, biodegradable antimicrobials, builders, fillers,
enzymes, thickeners and fluorescent brighteners, all of which are known classes of
materials in the fabric softening compositions field, with examples of several of
these being in the art mentioned in this specification.
[0033] The last component of the present compositions, which is present in those which are
aqueous emulsions (or dispersions), is water. Normally any clean water can be employed,
such as any of a hardness in the range of 0 to 500 p.p.m., as CaCO
3, bit it will be preferred to use water of a hardness of no more than 150 p.p.m.,
more preferably less than 50 p.p.m., and most preferably the water will be deionized
water that has been irradiated.
[0034] The invention is directed to detergent compositions (softergents) that contain the
described PEC and bentonite (or other suitable montmorillonite clay). Such detergent
compositions will contain at least one synthetic organic detergent of the anionic
or nonionic type (or a mixture thereof), which may also function as a dispersing agent
for the PEC.
[0035] The anionic detergents are normally of the water soluble sulfate and/or sulfonated
lipophile type, which may be designated "sulf(on)ated", and which include lipophile
and sulf(on)ate moieties, but analogous phosph(on)ates may also be utilised. Of the
synthetic anionic organic sulf(on)ated detergents those preferred are higher alkyl
(preferably linear alkyl) benzene sulfonates, higher fatty alcohol sulfates. Higher
fatty alcohol ethoxylate sulfates, olefin sulfonates and paraffin sulfonates. Usually
such compounds are water soluble alkali metal salts, such as sodium salts, and include
higher fatty alkyl or other aliphatic moieties, which serve as lipophilic moieties,
and which increase detergency, especially against greasy soils. Such higher alkyl
or higher aliphatic moieties will normally be of 8 to 22 carbon atoms, preferably
10 or 12 or 18 carbon atoms and more preferably, especially for the alkyl sulfates
and alkylbenzene sulfonates, the alkyl moieties will be of 12 to 14 carbon atoms.
The higher fatty alcohol ethoxylate sulfates that are useful will normally be of 1
to 20 ethoxy groups per mol, preferably 3 to 10 or 15, e.g. 3 to 7. As representatives
of anionic detergents there may be mentioned sodium linear dodecylbenzene sulfonate,
sodium linear tridecylbenzene sulfonate, sodium lauryl alcohol sulfate, sodium coco
alcohol triethoxylate sulfate, sodium C
16 paraffin sulfonate and sodium olefin sulfonate derived from C
14olefin.
[0036] Among the nonionic detergents those which are most preferred are ethylene oxide condensates
with higher fatty alcohols or with alkyl phenols, such as condensation products of
3 to 20, 5 to 15, 6 to 12 or 7 to 11 mols of ethylene oxide with higher fatty alcohols
of 10 or 12 to 18 or 13 to 17 carbon atoms or with alkyl phenols of 7 to 10 carbon
atoms in the alkyl groups, e.g., Dobanol® 25-7, Synperonic® A7, Neodol® 25-3, Neodol
25-7, Neodol 45-11, and C
13-17 alcohols condensed with 7 or 11 mols of ethylene oxide per mol. Although the improved
softening obtained when bentonite is employed with a PEC is noticeable in anionic,
nonionic and anionic/nonionic detergent compositions, such increase in softening action
is even more surprising in the case of nonionic detergent compositions because PEC
alone (without bentonite) has no fabric softening action at all in nonionic detergent
compositions (but does have some such action in anionic detergents).
[0037] In addition to the above examples of suitable anionic and nonionic detergents, extensive
listings of such detergents that are useful may be found in standard textbooks relating
to synthetic organic detergents, such as the McCutcheon texts, previously cited.
[0038] Of the water soluble builders for the anionic and nonionic detergents it is preferred
to employ water soluble salts, such as sodium or potassium salts, more preferably
sodium salts, and of these the carbonates, silicates, borates, bicarbonates and phosphates,
especially the polyphosphates, are preferred, such as sodium carbonate, sodium bicarbonate,
sodium silicate of Na
2O:SiO
2 ratio in the range of 1:1.6 to 1:3, preferably 1:2 to 1:3, e.g., about 1:3, 1:2.35
or 1:2.4, sodium tripolyphosphate and tetrasodium pyrophosphate, but sodium sesquicarbonate
and sodium sesquisilicate may also be used, as may be the corresponding potassium
and other soluble salts, when suitable. Of the water insoluble builders, which builders
also have water softening properties, the most preferred are the zeolites, especially
the hydrated zeolites. Such zeolites include crystalline, amorphous and mixed crystalline
and amorphous zeolites of both synthetic and natural origins, which are of satisfactorily
quick and sufficiently effective activities in counteracting calcium hardness ions
in wash waters. Preferably, the zeolites employed are characterised as having high
exchange capacities for calcium ions, which exchange capacity is normally from about
200 to 400 milligram equivalents of calcium carbonate per gram of the zeolite. Although
other ion exchanging zeolites may also be utilised, often the zeolite will be of the
formula
(Na
2O)
x . (Al
2O
3)
y . (SiO
2)
z . w H
2O ,
wherein x is 1, y is from 0.8 to 1.2, z is from 1.3 to 3.5 and w is from 0 to 9, and
preferably is 2.5 to 6. Of the crystalline zeolites that are useful those preferred
include Zeolites A, X and Y, with A being more preferable, and the most preferred
of these is Zeolite 4A. These zeolites are preferably in finely divided state when
added to the crutcher with the synthetic detergent prior to drying, and are of ultimate
particle diameters and actual sizes like those previously described for the bentonites.
Other builders that may be utilised include organic compounds, which are often sequestrants
for hardness ions. Such compounds include organic acids, especially hydroxy and amino
polycarboxylic acids, such as citric and gluconic acids and ethylene diamine tetraacetic
acid (EDTA) and nitrilotriacetic acid (NTA), all usually as their water soluble salts,
e.g., sodium salts. Additional useful builders are the organo-phosphorus chelating
agents, such as the Dequests®, e.g., Dequest 2046, which are manufactured by Monsanto
Co.
[0039] The proportions of components of the invented compositions and articles will be those
which result in stable and effective products for fabric softening applications. For
the PECs the concentrations in such liquid and gel softergent compositions will be
in the range of 2 to 20%, more preferably 2 to 15% and most preferably 3 to 10%, e.g.,
about 5 to 6%.
[0040] The particulate softergents will comprise 2 to 20% of PEC, preferably 2 to 15% and
more preferably 3 to 10%, e.g., 6%.
[0041] The bentonite or suitable clay content of the liquid or gel state softergents will
be in the operative range of 10 to 30% and preferably 15 to 20%, e.g., 16% or 18%.
For the particulate softergents such ranges are 10 to 30%, 10 to 25 %, 12 to 20% and
15 to 20%, respectively.
[0042] In the liquid or gel state and particulate softergents the operative percentage of
synthetic organic detergent is, respectively, 3 to 20% and 1 or 2 to 35 %, preferably
3 to 25 %, more preferably 3 to 20% and most preferably 5 to 15%. Preferably, the
synthetic organic detergent will be a mixture of anionic and nonionic detergents,
with the percentages thereof being in the ranges of 1 to 10% of each, preferably 1
to 5% of each and more preferably 1 to 3% of anionic detergent and 3 to 5% of nonionic
detergent, e.g., about 2% and about 4%, respectively. In the particulate or solid
built softergents the percentages of builder(s) will normally be in the range of 5
to 80%, preferably being in the range of 10 to 60%, more preferably 20 to 50% and
most preferably 30 to 40%, with the percentages of sodium tripolyphosphate, sodium
carbonate and sodium silicate, when such three builders are present, often being in
the ranges of 10 to 50%, 2 to 20% and 2 to 15%, respectively, preferably 15 to 35%,
2 to 10% and 2 to 10%, and most preferably 20 to 30%, 3 to 8% and 2 to 6%, e.g., about
23%, 6% and 4%, respectively. In liquid softergents such ranges of contents for synthetic
detergents and for builders will often be multiplied by a factor that is proportional
to the solids content of the liquid composition divided by the limiting solids contents
of the range for the particulate or solid product.
[0043] For invented compositions that contain emulsifier(s) the content(s) of such emulsifier(s)
will normally be in the range of 0.2 to 10%, preferably 0.4 or 0.5 to 5% and more
preferably 0.7 or 1 to 3%, e.g., about 1.25 or 2%. When the emulsifier contains both
an alkyl alkanolamine and an alkyl poly(ethylene oxide) ether, as may be preferred,
the proportion of the alkanolamine will usually desirably be equal to or greater than
that of the alkyl poly(ethylene oxide) ether alkanol, preferably being of 2 to 5 times
as much, e.g., about 4 times as much. Thus, such percentages can be of 0.2 to 5% of
the alkanolamine and 0.05 to 5% of the ether alkanol, preferably 0.3 to 3% and 0.1
to 2% and more preferably 0.5 to 2% and 0.2 to 1%.
[0044] Usually the total adjuvants content will be no more than 25%, preferably will be
no more than 15% and in many instances will be held to a limit of 5%. None of the
adjuvants, in the amounts employed, will be such as to cause unacceptable levels of
toxicity which could adversely affect aquatic organisms, including fish, that inhabit
lakes and streams into which there are fed washing machine effluents that included
the present compositions. Thus, the invented compositions may be considered to consist
essentially of the named components, or softergent form, with only environmentally
acceptable proportions of adjuvants being allowed to be present therein. As was previously
mentioned, the present compositions are preferably essentially free of quaternary
ammonium compounds. Most preferably 0% of such are present but when the resulting
compositions and articles are not ecotoxic increasing limits of 0.1%, 0.3% and 0.5%
may be imposed, which are more preferred, preferred and acceptable limits respectively,
under such circumstances, and are within the broader invention. Although the described
emulsifiers are more often employed in aqueous compositions, they may also be present
in solid or particulate products and the proportions thereof in such products will
be proportionally the same as for the liquids, on a solids basis.
[0045] A suitable adjuvant for the described products is an acidifying agent, such as hydrochloric
or other suitable acid, which is useful to adjust the pH of the emulsion or other
aqueous composition to within the range of 2.5 to 5.5, preferably 2.5 to 4, e.g.,
3.5. To do that the percentage of HCl (concentrated basis) or equivalent other acidifying
agent present will usually be in the range of 0.01 to 0.4%, preferably 0.05 to 0.2%.
A sodium-containing compound may be present to provide sodium ions (alternatively,
potassium compounds can be present) to convert alkaline earth or magnesium bentonite
to swelling alkali metal bentonite, in which case the proportion employed will usually
be at least stoichiometric, and may be up to 20% in excess of stoichiometric. Sodium
hydroxide may be a suitable source of sodium ions, especially for the softergent compositions
which are desirably alkaline.
[0046] To manufacture the invented solid, particulate and gel compositions is comparatively
simple, involving little more than mixings of components, (with gelling, and agglomeration
steps sometimes) but to produce applicants' dispersions a particular process is followed
(and that is the process of the working examples). In such cases it is preferable
that the PEC be melted before addition to the aqueous medium and the temperature to
which the PEC is raised will desirably be within 10 °C of the melting point thereof.
It is preferred that the PEC be mixed with any meltable emulsifier especially one
of lipophilic character (or more lipophilic character than another emulsifier present),
such as the alkanolamine, when a mixed alkanolamine/ether alcohol (or alkanolamine/ethoxylated
alcohol) emulsifier is employed, and melted together with it, but alternatively the
two meltable materials, PEC and alkanolamine, may be separately melted and added together
or simultaneously to the aqueous medium (usually water), which should also be at about
the same elevated temperature, about 60 °C., for example. The smectite clay may be
added before, with or after the emulsifier/PEC mixture. The water employed is often
desirably acidified, as by addition to it of HCl or other suitable acid, to generate
a final pH in the range of 2.5 to 5.5, preferably 2.5 to 4.0, e.g., about 3.5. After
emulsification the emulsion produced may be cooled to room temperature, with the balance
of emulsifier being added before or after such cooling, preferably before. The result
is a stable emulsion which resists separation under normal elevated temperature conditions
for periods of six months or more.
[0047] To manufacture the particulate or powdered product it is only required for the PEC
to be mixed with the smectite clay and any other components of the formulation. Preferably,
the melted PEC, at elevated temperature, will be sprayed onto a tumbling mass of the
particulate agglomerated smectite or montmorillonite powder (such as bentonite) or
agglomerate thereof with any other particulate materials of the product, and will
thereby be distributed throughout it evenly. Sometimes the mixer employed will include
size reduction means to make sure the PEC is in small enough particles so as to be
depositable evenly on the laundry being treated. The bentonite or other smectite clay
particles may be at room temperature when the PEC is being applied to them and the
PEC will be solidified on contact with the particulate mass, usually with little agglomeration
taking place, but by controlling the PEC application, the temperature and mixer speed,
some agglomeration may be obtainable, when desired.
[0048] The softergents may be made in usual manners, with the PEC and bentonite being post-added
or being added at a suitable stage of the manufacturing process, including crutching
and spray drying, taking into account that they will not be subjected to destabilising
or destructive temperatures.
[0049] In use the various invented compositions are employed in the same manners as are
other softergents that apply fabric softener to laundry. Softergents may be charged
to the washing machine as if they were detergents, with the desired concentrations
being in the range of 0.1 to 1%, preferably 0.1 to 0.5% e.g., about 0.15% in the U.S.A.
and about 0.5% in Europe, to compensate for different washing conditions employed.
[0050] The following examples illustrate but do not limit the invention. Unless otherwise
indicated all parts and percentages in this specification and the appended claims
are by weight, and all temperature in °C.
EXAMPLE 1
[0051]
Component |
% By Weight |
|
Sodium linear dodecylbenzene sulfonate |
2.00 |
|
Stearyl hydroxyethyl imidazoline |
1.00 |
* |
Nonionic detergent |
3.90 |
** |
Sodium silicate |
4.00 |
|
Sodium tripolyphosphate |
23.00 |
|
Sodium carbonate, anhydrous |
6.00 |
|
Ethylenediamine tetra(methylene phosphonic acid) sodium salt |
0.38 |
*** |
Optical brightener |
0.21 |
**** |
Methyl silicone |
0.18 |
|
Sodium hydroxide |
1.00 |
|
Sodium perborate tetrahydrate |
12.00 |
° |
Proteolytic enzyme |
0.30 |
°° |
Calcium montmorillonite swellable clay |
16.00 |
|
Potassium methyl siliconate |
0.50 |
|
Hydroxylamine sulfate |
0.30 |
|
Perfume |
0.50 |
|
Tetraacetylethylenediamine |
0.89 |
|
Sodium aluminosilicate |
0.25 |
°°° |
Pentaerythritol distearate |
6.00 |
|
Sodium sulfate, anhydrous |
10.59 |
|
Water |
11.00 |
|
|

|
* Condensation product of one mol of mixed C13-17 alcohols and seven mols of ethylene oxide |
** Na2O:SiO2 ratio of 1:2 |
*** Diaminostilbene disulfonic acid salt type |
**** Dow-Corning X2-3302 |
° Alcalase 2T |
°° Calcium bentonite |
°°° Commercial, 14% monostearate, 45% distearate and 40% tristearate |
[0052] A particulate built fabric softening detergent composition (a softergent) of the
above formula is made by spray drying a portion of the formula to produce base beads,
and then admixing such beads with a mixture of the remaining components, except for
the perfume, which is sprayed onto the mixture of the beads and other materials. The
spray dried beads are made by spray drying a crutcher mix of various heat stable components
of the product, including sodium sulfate, sodium linear dodecylbenzene sulfonate,
stearyl hydroxyethyl imidazoline, nonionic detergent, sodium silicate, sodium tripolyphosphate,
sodium carbonate, ethylenediamine tetra(methylene phosphonic acid) sodium salt, optical
brightener, silicone, sodium hydroxide, PEC and water, with the solids content of
the crutcher mix being about 55%, to base beads of particle sizes in the range of
10 to 100, U.S. Sieve Series which has openings 2.00 to 0.149 mm across. The bentonite
is agglomerated to the same particle size range and the agglomerated bentonite and
the other components (usually those which are heat sensitive), including the sodium
perborate tetrahydrate, the enzyme, the hydroxylamine sulfate and the sodium aluminosilicate,
are admixed with the base beads, after which the siliconate and perfume are sprayed
onto the mixture resulting, to make the final softergent. In a variation of the manufacturing
procedure the PEC may be post-added to the composition in powdered form or as a co-agglomerate
with bentonite.
[0053] The softergent produced and variations of the formula, in which percentages of the
bentonite and PEC are varied while all the other percentages of components remain
the same, except for the sodium sulfate, which is changed to compensate for increases
or decreases in the total of bentonite and PEC, are made and are tested for detergency
and fabric softening effectivenesses. In tests against various oily and clayey soils
the softergent is found to be an effective and commercially acceptable detergent,
using visual observations of the cleaning of soiled laundry and test swatches as well
as reflectometer reading comparisons with controls. When tested against the best commercial
softergent known to the present inventors, which composition includes clay, tertiary
amines, polysiloxanes and soap or quaternary ammonium compound, the invented composition
of the formula given above is as good as such "ultimate" composition or better in
fabric softening effect, using 60 °C washing machine laundering of ordinary wash loads
of dirty laundry or test swatches, whether the washing machines and procedures are
of the American or European type, and whether the materials of the items washed are
natural, such as cotton, synthetic, such as polyester, or blends thereof. In such
tests a panel of experienced evaluators, usually at least four, compares washed swatched
(or identical items), one of which was washed by a control detergent composition and
the other of which was washed using a softergent that is being evaluated. The difference
in softness is judged and a number is assigned to indicate such difference with 1
being for a slight difference, 2 being for a moderate difference and 3 being for a
great difference. In all cases, of course, the swatches washed with the softergent
will be softer than the control, which was washed in wash water that contained a detergent
composition from which the softening bentonite-PEC combination has been omitted.
[0054] When the invented softergent of the formula of this example is tested against a control
detergent, from which the bentonite and PEC were omitted and replaced by sodium sulfate,
an inert filler, the difference in softening effect is rated at 2.3. When the 6% of
PEC is in the formula but the bentonite is omitted and is replaced by sodium sulfate
the rating is 0.7 and when the PEC is replaced by sodium sulfate and the bentonite
(16%) is present, the rating is 0.8. Thus, the additive effect of the PEC only and
bentonite only formulas would be 1.5 whereas actually it is found to be 2.3, which
represents a very significant improvement (synergism). Even greater fabric softening
action is obtainable, as will be evident by reference to the appended drawing, which
also shows that merely increasing the proportion of either bentonite or PEC does not
yield the same improvement; in fact, increasing the proportions of bentonite to 30%
and PEC to 20% (separately) results in decreasings of the softening actions.
[0055] The synergistic result with respect to fabric softening actions of the invented softergents
will readily be apparent from the appended drawings, in which:
FIG. 1 is a plot of fabric softening effect of a composition of the basic formula
of Example 1 of this specification, with the bentonite content being varied, compared
to such softening effect of similar compositions in which the bentonite content is
varied and the PEC content is 0%; and
FIG. 2 is a plot of fabric softening effect of a composition of the basic formula
of Example 1, with the PEC content being varied, compared to such effect in similar
compositions in which the PEC content is varied and the bentonite content is 0%.
[0056] In FIG. 1 curve 11 shows the increase in fabric softening action on the washed laundry
as the bentonite content is increased from 0 to 25%, with the dots on the curve representing
specific bentonite contents. The best softening obtained is rated at about 2.7, which
is about the best ever obtained with a softergent. Curve 13 illustrates fabric softening
action as the bentonite content is increased, with the PEC being omitted from the
formula. It is notable that the curve heads downwardly, indicating less softening,
when the bentonite content is over 25%. Phantom curve 15 shows the expected additive
effect on fabric softening action of the 6% of PEC plus the indicated percentages
of bentonite. Because curve 15 is substantially lower than curve 11 for most of its
length it proves that a synergistic fabric softening effect attends the presence of
both bentonite and PEC in the described softergents composition.
[0057] FIG. 2 is similar to FIG. 1 except that in the FIG. 2 experiments it is the clay
(bentonite) content that is being held constant while that of the PEC is being varied,
from 0 to 20%. Curve 17 shows the increase in fabric softening action of softergents
of the invention which contain 16% of clay and from 1 to 10% of PEC, while curve 19
shows that when the clay content is 0% the increase in softening action as the PEC
content is increased is at a lower rate, and softening actually decreases at higher
PEC contents. Curve 21 plots the expected (additive) effect of 16% of clay plus the
indicated percentages of PEC. Because such curve is substantially lower than the actual
curve 17 it is established that the combination of bentonite and PEC synergistically
improves fabric softening of laundry washed with such softergents.
[0058] The described effect, synergistic improvement of fabric softening action, is also
obtained with various other combinations of PECs described herein and montmorillonite
clays of the types mentioned but the best results are obtained when the PECs are partial
esters of pentaerythritol and pentaerythritol oligomers which include at least one,
and preferably two hydroxyls, and when the clay is a calcium bentonite or a sodium
or potassium bentonite that is capable of swelling in the wash water. In the experiments
described above and plotted in the graphs of the figures the bentonite employed is
calcium bentonite and there is enough sodium ion in the wash water (from the builder
salts and the sodium hydroxide) to convert it to swelling sodium bentonite. Surprisingly
enough, the calcium bentonite, when employed under such conditions, is even better
in fabric softening power than the sodium and potassium bentonites.
[0059] Another significant advantage of the invented softergents of this invention is in
the breaking through of a perceived "softening barrier" by the invention. From FIGs.
1 and 2 it is evident that increasing the contents of either bentonite or PEC alone
will not result in a superior softergent because the softening effect asymptotically
approach limits less than or about 1 and even the additive effects which could be
predicted are less than 2, and in all cases the fabric softenings are diminished as
greater proportions of the mentioned softening agents are employed. Yet, with the
invented compositions this apparent limit on softening power is transcended and less
total quantities of the combination of PEC and bentonite yield superior results, with
the fabric softening effects approaching those for rinse cycle additive compositions,
which had previously been considered to be "an impossible dream". Such effects are
obtainable with other types of softergents, including those based on nonionic detergents
only, anionic detergents only, water insoluble binders, such as zeolites, non-phosphate
formulas, in which the builder composition can be a combination of zeolite, carbonate
and silicate, and softergents built with organic builders, such as polyacetal carboxylates,
NTA, EDTA, citric acid and gluconic acid.
EXAMPLE 2
[0060]
Component |
% By Weight |
|
Sodium linear dodecylbenzene sulfonate |
3.00 |
|
Stearyl hydroxyethyl imidazoline |
1.50 |
* |
Nonionic detergent |
3.50 |
|
Sodium silicate (Na2O:SiO2 = 1:2) |
5.50 |
|
Zeolite 4A |
19.00 |
|
Sodium maleate methacrylate copolymer |
1.10 |
|
Sodium carboxymethyl cellulose |
0.50 |
|
Sodium carbonate, anhydrous |
4.00 |
|
Ethylenediamine tetra(methylene phosphonic acid) sodium salt |
0.44 |
|
Stilbene optical brightener |
0.25 |
|
Sodium hydroxide |
0.10 |
|
Proteolytic enzyme (Alcalase® 2T) |
0.36 |
|
Sodium perborate tetrahydrate |
10.60 |
|
Calcium montmorillonite clay (calcium bentonite) |
18.00 |
|
Hydroxylamine sulfate |
0.50 |
|
Tetraacetylethylenediamine |
1.00 |
|
Sodium aluminosilicate |
0.40 |
|
Sodium ethylenediamine tetraacetate |
0.13 |
°°° |
Pentaerythritol distearate |
3.00 |
|
Sodium sulfate, anhydrous |
19.07 |
|
Water |
7.50 |
|
Perfume |
0.55 |
|
|

|
* Condensation product of one mol of mixed C13-17 alcohols and seven mols of ethylene oxide |
°°° Mixture of 14% of the monostearate, 45% of the distearate and 40% of the tristearate |
[0061] The particulate product of this example is made by a procedure described in Example
1, and, when tested for detergency and fabric softening properties according to the
procedures set forth in that example, exhibits good detergency and synergistic fabric
softening, due to its contents of PEC and bentonite. The synergistic improvement in
fabric softening, compared to the expectable effects of the individual PEC and bentonite
in such composition, is not as striking as in Example 1 (wherein 6% of PEC and 16%
of bentonite were present) but is significant. In variations of this non-phosphate
formula the PEC content is increased to 6% and the sodium sulphate content is decreased
to 1.5%, with a corresponding increase in sodium sulfate content to 20.57%, and synergistic
fabric softening is still noted, but to a lesser extent. When the PEC content is decreased
to 16.07% to compensate, the synergistic fabric softening effect is even more pronounced.
EXAMPLE 3
[0062]
Component |
% By Weight |
* |
Nonionic detergent |
12.00 |
|
Sodium silicate (Na2O:SiO2 = 1:2) |
5.50 |
|
Zeolite 4A |
23.00 |
|
Sodium maleate methacrylate copolymer |
1.50 |
|
Sodium carboxymethyl cellulose |
0.55 |
|
Sodium carbonate, anhydrous |
13.00 |
|
Ethylenediamine tetra(methylene phosphonic acid) sodium salt |
0.65 |
|
Stilbene optical brightener |
0.30 |
|
Sodium hydroxide |
0.15 |
|
Sodium perborate tetrahydrate |
9.00 |
|
Proteolytic enzyme (Alcalase 2T) |
0.70 |
|
Calcium bentonite |
18.00 |
|
Hydroxylamine sulfate |
0.50 |
|
Tetraacetylethylenediamine |
3.86 |
|
Sodium aluminosilicate |
0.50 |
°°° |
Pentaerythritol distearate |
3.50 |
|
Water |
6.54 |
|
Perfume |
0.75 |
|
|

|
* Condensation product of one mol of mixed C13-17 alcohols and seven mols of ethylene oxide |
°°° Mixture of 14% of the monostearate, 45% of the distearate and 40% of the tristearate |
[0063] The zeolite-built, non-phosphate, nonionic particulate detergent composition of this
example is made by the process or processes of Examples 1 and 2 and is tested for
detergency and fabric softening properties in the same manner. It is a good nonionic
detergent and does not have the ecologically disadvantageous properties of phosphates
or non-biodegradable anionic detergents. Also, due to its content of calcium bentonite
and PEC it is of excellent fabric softening properties, synergistically better than
would have been expected from the additive effects of the fabric softening agents
present in the formula (and PEC is biodegradable).
[0064] To improve detergency of the composition even more one may incorporate in it an anionic
detergent of the biodegradable type, such as 5% of sodium lauryl sulfate or 10% of
sodium C
14-15 paraffin sulfonate, and in some instances such anionic detergents may replace the
nonionic detergent, with the total detergent content being about the same as in the
formula of this example. Such products also exhibit the excellent fabric softening
properties of the formula of this example and such fabric softening is synergistically
improved over the additive effects of the fabric softening components of the product.
EXAMPLE 4
[0065]
Component |
% By Weight |
|
Sodium linear tridecylbenzene sulfonate |
6.00 |
+ |
Neodol® 25-7 |
4.00 |
|
Pentaerythritol distearate |
7.00 |
|
Swellable calcium bentonite |
18.00 |
|
Sodium carbonate |
8.00 |
|
Sodium silicate (Na2):SiO2 = 1:2.4) |
4.00 |
++ |
Emulsifier |
2.00 |
|
Water |
51.00 |
|
|

|
+ Nonionic detergent which is a condensation product of a fatty alcohol of 12-15 carbon
atoms, with 7 mols of ethylene oxide. |
++ Mixture of 4 parts of N-stearyl diethanolamine and 1 part of C12-15alkyl decaethoxy ethanol. |
[0066] This basic liquid softergent formula yields an excellent cleaner and fabric softener,
which exhibits the synergism of the fabric softening components, previously described
in Examples 1-3.
EXAMPLE 5
[0067] In this example cotton terrycloth swatches are washed in an automatic washing machine
in a 60 °C wash water containing 0.5% of a softergent composition of the formula of
Example 1, rinsed and dried. Other such swatches are washed in conventional detergent
compositions, which may be of the same formula except for the omission of the bentonite
and PEC, which are replaced by inert filler (sodium sulfate), and are then rinsed
(in the last rinse), with rinse water to which any quaternary ammonium or amine salt
rinse cycle fabric softening composition has been added, such as dimethyl distearyl
ammonium chloride, so that the rinse water contains about 0.05% (or more) of the fabric
softening quat or amine, and such swatches are dried.
[0068] Strips are cut of swatches subjected to these different treatments and are tested
for water absorption, by dipping lower ends of such vertical strips into an aqueous
solution of water soluble dye (red Iragon) and measuring the heights to which the
water rises, after 30 seconds, 1 minute, 3 minutes and 5 minutes. The strips washed
with the invented softergent absorb water to heights that are about twice those for
the strips from the swatches that are washed, as described, and then treated with
the rinse cycle softener.
[0069] The invented softergents soften the cotton (and other fabrics) about as well as the
best of comparable softening compositions, which is an exceptional result.
[0070] The results of these tests and similar absorption tests on towelling and clothing
are important because they show that fabrics treated with the invented compositions,
instead of commercial quat-based products, are more capable than such products of
absorbing water (which is important for towels) and body sweat (which is important
for clothing items, such as underwear, T-shirts and sport apparel).
[0071] In the illustrative examples of the invention given above various changes may be
made within the invention and the described synergistic results will still be obtained.
For example, various other swellable bentonites and montmorillonites may be substituted
for the calcium and sodium bentonites and other PECs may be employed, including dipentaerythritol
tetralaurate, monopentaerythritol 10 ethylene oxide distearate and pentapentaerythritol
tetrapalmitate.
[0072] Different detergents, PECs and clays like those mentioned may be employed and various
adjuvants and active components may be included in the compositions and articles of
the invention, and so long as the combination of the acceptable clay and PEC is present
the synergistic fabric softening action is obtainable. Such is also the case when
proportions are varied within the ranges mentioned and when different concentrations
of the products are employed, within the ranges given.
[0073] In all variations, when the bentonite and the PEC of the present invention are present
improved softening results, possibly due to the mutual promotion of adherence to the
laundry fibers of each of the required softeners, and sometimes to the desirable dispersing
effect of the bentonite on the PEC. However, it seems that the synergism obtained
is due to more than the mentioned adherence promoting and dispersing effects, and
applicants are not bound by any theories mentioned herein.
[0074] The invention has been described with respect to illustrations and examples thereof
but is not to be considered as being limited to those because it is evident that one
of skill in the art, with the present specification before him or her will be able
to utilise substitutes and equivalents without departing from the scope invention
as defined in the appended claims.