[0001] This invention relates to fabric softening compositions for application to laundry
during washing to apply to the fibers of the fabrics of such laundry fabric softening
amounts of fabric softening components of the compositions. More particularly, it
relates to such products that include as fabric softening components higher fatty
acid esters of pentaerythritol, of pentaerythritol oligomers, or of alkoxylated derivatives
thereof, all of which may be designated PEC (for pentaerythritol compound), together
with a dispersing agent for such PEC, such as a clay or an emulsifier and which do
not essentially 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, and such articles
include paper strips and sponges that have been impregnated with fabric softener.
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 effectively
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".
Articles that contain a fabric softening component, such as a quaternary ammonium
salt, may be added to the automatic laundry dryer wherein, during tumbling of the
laundry in a heated environment, the fabric softener is applied to the laundry by
repeated contact, and softens it.
[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 components
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 and with the others being lower alkyl(s) of 1 or 2 carbon atoms,
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 lead to attempts to find replacements for them. For example, being cationic,
they tend to react with anionic materials, such as anionic synthetic organic detergent
and builders for synthetic detergents, sometimes to the detriment of their intended
fabric softening function. Moreover, 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 be emptied.
[0005] EP-A-494769 is only 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. This liquid may be
mixed with liquid detergent composition for use in the washing step.
[0006] In US-A-4128484 discloses a rinse-added softening composition comprising a fatty
acid partial ester of a polyhydric alcohol as softener and a cationic surfactant.
[0007] JP-A-2047362 discloses and teaches three component compositions containing
(A) a quaternary ammonium salt containing defined C10-24 carbon atom groups;
(B) a fatty acid compound containing C8-24 carbon atoms; and
(C) a pentaerythritol ester of a fatty acid of 10-24 carbon atoms in which the ratio
of B/A is in the range 0.0001:1 to 0.4:1, the ratio of C/A is in the range 0.01:1
to 0.5:1 and the total of A+B+C is in the range 3-25% by weight.
[0008] EP-A-243735 discloses compositions containing 1 to 15% of quaternary ammonium compound
with specific constituent group and 0.5 to 5% of a carboxylic acid ester, the ratio
of the quat to the ester being 10:1 to 1:1. The examples of this document use glycerin
monostearate as the ester.
[0009] In efforts to find replacements 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, 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 may be discharged into sewage and drainage systems.
[0010] In accordance with the present invention a fabric softening built 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 dispersing agent for the
PEC, a synthetic organic detergent, and a detergent builder which composition is essentially
free of quaternary ammonium compound fabric softener, or other quaternary ammonium
compounds, the dispersing agent being an emulsifier or a fabric softening clay, the
composition containing 3 to 35% by weight detergent, 5 to 80% by weight builder, 0.5
to 25% by weight adjuvants, 1 to 25% by weight of PEC and 0.2 to 90% by weight of
dispersant.
[0011] Of the PECs those which are preferred are the pentaerythritol distearates and dipentaerythritol
dilaurates, and of the dispersing agents those preferred are ethoxylated amines or
alkanolamines which are positively charged at acidic pHs, such as 2.5-4, or montmorillonites,
such as sodium, calcium and potassium bentonites. The invention also includes processes
for softening laundry with the invented compositions.
[0012] The composition may also comprise an anionic or nonionic synthetic organic detergent
or a mixture thereof.
[0013] The invention in the form of an aqueous liquid composition preferably contains 3-15%
of detergent, 5-25% of builder, 0.5 to 15% of adjuvant(s), 3 to 15% of PEC and 3 to
30% of emulsifier.
[0014] The invention in the form of a particulate composition preferably contains 3 to 35%
of detergent, 10 to 80% of builder, 0.5 to 25% of adjuvant(s), 2 to 15% of PEC and
5 to 30% of fabric softening clay.
[0015] Preferably the dispersant is a fabric softening clay and no quaternary ammonium compound
is present.
[0016] A search of prior art relevant to the invention 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. patent 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 esters 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 esters, and among the carboxylic acid
esters are mentioned esters 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 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 suitable dispersing agent as a fabric softener in place
of a quaternary ammonium compound or quat softener and would have essentially as good
a softening action, and none of the disclosures mentions any specific pentaerythritol
ester as a fabric softening agent nor does any mention any 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] The main component of the invented compositions of the present invention, which is
usually the only fabric softening compound in such products, other than a fabric softening
clay, such as bentonite, which may also be present in them, is C
l2-C
22 (hereafter 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 ester of pentaerythritol oligomers, higher fatty acid ester 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 as the esters, as will 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
single 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. 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 thereof will be 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). Usually
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 12 to 22 and preferably 12 to 18, e.g., lauric,
myristic, palmitic, oleic, stearic and behenic acids. Such may be mixtures of such
fatty acids, obtained from natural sources, such as coco fatty acid, commercial stearic
acid, tallow acid or hydrogenated tallow acid. Intermediate 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, somethimes depending on the pentaerythritol moiety
esterified.
[0024] The PECs utilised in this invention have some fabric softening effects but such activities
are remarkably increased when a suitable dispersing agent for the PEC is present with
it. In the absence of such an agent the PEC may be substantially insoluble and undispersed
in wash water or in rinse water, in which, if dispersed, it could be conveniently
applied to laundry to be softened. 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).
[0025] Suitable dispersing agents include emulsifiers, usually employed to "solubilise"
or disperse the PEC in aqueous liquid compositions that are intended to be employed
as rinse cycle softeners (although they may also be added to the wash water), and
solids of small (often micron size) ultimate particle sizes, such as clays, which
may be present in particulate and other products, and in liquid products, too.
[0026] The emulsions (which term herein is also intended to refer to dispersions and suspensions
in liquid media, as well as to microemulsions [and sometimes solutions may be present,
too, in which solvents are the "dispersing agents"]) of this invention will normally
be aqueous emulsions in which the aqueous phase is the continuous phase, with the
pentaerythritol compound being in the dispersed 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 stable products, and may also be in the continuous
media or solutions.
[0027] 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 hydroxyalkyl 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 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.
[0028] When instead of emulsion form for the invented compositions it is desired that they
be in particulate or powder form the dispersing agent for the active pentaerythritol
compound softening agent may be any suitable such particulate or powder material that
is compatible with the mentioned softening agent, and can contribute some fabric softening
action to the composition. Such a material is bentonite but other fabric softening
clays and clay-like materials may be substituted for it, at least in part. Also, other
non-functional substantially water insoluble dispersing agents may be utilised and
such, like calcium carbonate and silica, may be carriers for the PEC, and even water
soluble carriers, such as sodium sulfate and other "filler salts" may be used, at
least in part with the dispersing agent, and sometimes can act as dispersing agents,
too. The bentonite employed should preferably 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).
If desired, an emulsifier may be utilised in the particulate or solid compositions,
and bentonite, or other dispersing clays may be present in the emulsions or dispersions,
or other swelling clays may be used.
Normally, in the various applications mentioned, the PEC will be employed without
the presence of any other fabric softening material (except clay, such as bentonite,
montmorillonite or other 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 so 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 as long as the composition is essentially free
of quats. 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 is often unacceptable,
environmentally. Such antistats and fabric softeners include: higher alkyl neoalkanamides,
e.g. N-stearyl neodecanamide; isostearamides; amines, such as N,N-ditallowalkyl N-methyl
amine; amidoamines; imidazolines; di-higher fatty acid esters of di-lower alkanolamines,
such as dicoco acid ester of diethanolamine; silicones; alkoxylated silicones; and
clays, e.g., bentonites and other montmorillonites; and representative examples of
some of such classes of such compounds are given below.

CLAY
[0029] = 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 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 and so that the compositions
are essentially free of quats.
[0030] 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 given in the art mentioned in this specification.
[0031] The last component of the present compositions, which is required in the aqueous
emulsions, 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, but 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.
[0032] The invention is directed to detergent compositions (softergents) that contain the
described PEC and suitable dispersing agent. Such detergent compositions will contain
at least one synthetic organic detergent, preferably of the anionic or nonionic type
(or a mixture thereof), which may act as a dispersing agent for the PEC.
[0033] The anionic detergents are normally of the water soluble sulfated and/or sulfonated
lipophile type, which may be designated "sulphonated", and which include lipophilic
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 to 16 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 such 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
14 olefin.
[0034] 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 a dispersing agent, such as bentonite, is employed with a
PEC is noticeable in anionic detergent compositions, such softening action is increased
even more when the detergent composition contains a nonionic detergent with the anionic
detergent or in replacement of it because the nonionic detergent/PEC is inactive.
[0035] 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.
[0036] Of the water soluble builders for such 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, more preferably
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 1:2, 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 . wH
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 in the micron range, e.g. 0.01 to 20 microns, and actual particle
sizes in the range of Nos. 100 to 400 sieves, preferably 140 to 325 sieves, US Sieve
Series (which have openings 0.149 to 0.037 mm across and 0.105 to 0.044 mm across
respectively). 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 acids, such as citric and gluconic acids usually as their water
soluble sodium salts, and ethylene diamine tetraacetic acid (EDTA) and nitrilotriacetic
acid (NTA), also usually as their water soluble salts, e.g., sodium salts. Although
sodium salts are preferred other acceptable water soluble salts of the organic builder
acids may also be utilised. Additional useful builders are the organo-phosphorus chelating
agents, such as the Dequests®, e.g., Dequest 2046, which are manufactured by Monsanto
Co.
The present softergents normally comprise 3 to 35% detergent, 10 to 80% builder, and
0.5 to 25% adjuvants for the particulate or solid softergents, preferably 3 to 25%,
10 to 60% and 2 to 15%, respectively, and 3 to 20%, 5 to 35% and 0.5 to 20%, respectively,
for the liquid softergents (with the balance being water or most water), preferably
3 to 15%, 5 to 25% and 0.5 to 15%, respectively. The percentages of PEC and dispersant
are in the ranges of 1 to 25% and 0.2 to 90%, preferably being 2 to 15% and 5 to 30%
for the solids and 3 to 15% and 3 to 30% for the liquids, respectively.
[0037] The proportions of components of the invented compositions will be those which result
in stable and effective products for fabric softening applications. For the PECs the
concentration in such compositions will normally be in the range of 1 to 25%, preferably
1 to 10%, more preferably 2 to 8% and most preferably 3 to 7%, e.g. about 5 % .
[0038] For the emulsions the content(s) of 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 is made from an alkyl alkanolamine and an alkyl
poly(ethylene oxide) ether, the proportion of the alkanolamine will desirably be equal
to or greater than that of the alkyl poly(ethylene oxide) ether, 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 amine compound and 0 to 5% of the ether compound, preferably 0.3
to 3% and 0.1 to 2% and more preferably 0.5 to 2% and 0.2 to 1%. For example, as in
the composition of the working example, the percentages of such emulsifiers may be
1% of the amine compound and 0.25% of the ether compound. The aqueous medium or water
contents of such compositions may be the balances thereof. It is to be understood
that the presences of any adjuvants or supplemental components of the emulsions will
be compensated for by corresponding decreases in the water contents of the compositions.
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 rinses that included the present compositions.
Thus, the invented compositions may be considered to consist essentially of the named
components, in the additive or softergent form, with only environmentally acceptable
proportions of adjuvants being allowed to be present therein. As was previously mentioned,
the present compositions are essentially free of quaternary ammonium compounds.
[0039] One suitable adjuvant is an acidifying agent, such as hydrochloric acid, which is
useful to adjust pH of the emulsion or other aqueous composition to 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%.
[0040] When particular or powder compositions are made the percentages of PECs may be in
the same ranges as given in the preceding paragraph or at least within the wider of
such ranges but the powder carrier/dispersing agent may be the balance of the composition.
If desired, emulsifier(s) may also be present in such compositions, preferably in
about the proportions previously given for the emulsions, and of course, suitable
adjuvants may be present, too.
[0041] To manufacture the invented compositions is comparatively simple but to produce applicants'
desired stable emulsions (and microemulsions) a particular process is desirably followed.
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 amine, when a mixed amine-monoether or -ethoxylated
alcohol emulsifier is employed, and melted together with it, but alternatively the
two meltable materials, PEC and amine, 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 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 (the monoether or ethoxylated alcohol emulsifier, in many cases) 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.
[0042] To manufacture the particulate or powdered product it is only required for the PEC
to be mixed with the dispersing material. 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 other disperser/carrier,
and will thereby be distributed throughout it evenly. Sometimes the mixer employed
will include size reduction means to make sure that the PEC is in small enough particles
so as to promote even depositions on the laundry being treated. The bentonite or other
disperser 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.
[0043] The softergents may be made in usual manners, with the PEC and disperser being post-added
or being added at a suitable stage of the manufacturing process, taking into account
that they will not be subjected to destabilising or destructive temperatures.
[0044] 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.
[0045] 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 temperatures are in °C.
EXAMPLE 1 (not within the scope of the invention)
[0046]
| |
Component |
Percent (by weight) |
| |
Pentaerythritol distearate |
5.00 |
| (1) |
Genamin® S-020 |
1.00 |
| (2) |
Genapol® OX-100 |
0.25 |
| |
Hydrochloric acid (concentrated) |
0.087 |
| |
Water, deionized |
93.663 |
| |
|

|
| (1) N-stearyl diethanolamine (which can be replaced by N-tallow triethanol propylenediamine) |
| (2) Alkyl poly(ethylene oxide) ether ethanol wherein the alkyl is a mixture of C12-15 alkyl chains, and which contains about 10 EO groups. |
[0047] A stable emulsion is made of the above formula by heating together the pentaerythritol
distearate and the Genamin S-020 to 60 °C and then admixing such melted mixture with
the 60 °C acidified water, after which the Genapol OX-100, also at 60 °C, is admixed
with the water emulsion of pentaerythritol distearate and Genamin S-020. The resulting
stable acidic emulsion, which is at a pH of about 3.5, is a good fabric softening
composition, better in fabric softening action than a 5% aqueous emulsion or suspension
of distearyl dimethyl ammonium chloride (DSDMAC), when tested against such quat, using
hardened cotton terrycloth as the test fabric to be softened. DSDMAC has long been
considered to be one of the most effective fabric softeners known in the art.
[0048] In the described tests the terrycloth employed is hardened by six treatments with
an aqueous hardening composition that includes sodium silicate, sodium sulfate and
sodium tripolyphosphate.
When comparing two fabric softening compositions for softening action nine tests are
run on each of such compositions, using 40 cm x 40 cm hardened terrycloth swatches
and washing each of them and rinsing them in rinse waters containing either of the
fabric softening compositions. Evaluations of softening actions (or softnesses of
the treated swatches) are made after 1, 5 and 10 washing/rinsing cycles, by six judges
in blind comparison tests. The washings effected are normal washing machine washings
and the rinsings are in rinse waters containing 110 ml of softening composition per
25 litres of water (0.44%, by weight), which are employed to treat 3 kg of fabric
or laundry, containing the test swatches. In some instances a mini-test may be carried
out, using specially designed reduced scale washing and rinsing apparatuses, and it
has been found that such test results are consistent with those from the full size
tests. After rinsing, the swatches are air dried in a temperature- and humidity-controlled
room, while being maintained horizontal to prevent loss of the fabric softener from
the fabric due to dripping. After drying the swatches are ready for softness evaluation
by the jury.
[0049] The judges rate the swatches for softness by comparing them to a standard, which
in the present case is a swatch that was treated with a softening composition that
contained the same amount of DSDMAC as the amount of pentaerythritol distearate in
the test composition. The judge's ratings are evaluated, using statistical techniques,
and final results show whether the softening compositions are equal in softening actions
or whether one or the other is significantly better. By the described testing the
experimental composition of this example is rated as better in fabric softening effect
than a control composition that contained the quat (DSDMAC), whether one, five or
ten cycles of washings and rinsings are used.
[0050] In similar separate testings, employing pentaerythritol dilaurate and pentaerythritol
dibehenate, it was found that although such compositions were useful fabric softeners,
they were not as effective as pentaerythritol distearate. Also, pentaerythritol monostearate
and pentaerythritol tristearate compositions, while possessing useful fabric softening
properties, were not as effective in that respect as the pentaerythritol distearate.
In the above experiments instead of pure pentaerythritol distearate the pentaerythritol
ester may be the di-tallowate or di-hydrogenated tallowate, in which the esterifying
acid is tallow acid(s) or hydrogenated tallow acid(s), and the results obtained will
be similar. Also, when other dispersing agents, such as those described earlier in
this specification, are employed with any of the mentioned PECs, effective softening
is also obtained.
EXAMPLE 2 (not within the scope of the invention)
[0051] The procedure of Example 1 is followed, with the exception that in the formula thereof
the pentaerythritol distearate is replaced by tripentaerythritol tetralaurate, and
it is found that the softening action of such acidic compositions, which are at pHs
in the range of 2.5 to 5.5, is comparable to that of the pentaerythritol distearate
composition of Example 1. The tetralaurate is superior in softening action to analogues
thereof wherein the ester is the tetrastearate and/or tetrapalmitate and/or tetraoleate,
and it appears that such differences are related to the maintenance of a more desirable
hydrophilic/lipophilic balance (HLB), inasmuch as the tripentaerythritol tetraester
has fewer free hydroxyls per carbon atom than the pentaerythritol diester.
[0052] Instead of the tripentaerythritol tetralaurate there may be substituted tripentaerythritol
tetramyristate, tripentaerythritol tristearate, tripentaerythritol tritallowate, tripentaerythritol
trihydrogenated tritallowate, dipentaerythritol tetrastearate, dipentaerythritol trilaurate,
tetrapentaerythritol tetralaurate, pentapentaerythritol tetrastearate and pentapentaerythritol
tetratallowate and various others of the pentaerythritol esters are described herein,
and fabric softening similar to that of the tripentaerythritol tetralaurate will be
obtainable, without the need for the presence of quat fabric softener. In addition,
the described emulsions are stable, the fabric softening component is satisfactorily
rewettable and may aid perfume to adhere to the treated fabric, and the presence of
the dispersed PEC in a softergent and in wash water prevents excessive foaming.
EXAMPLE 3 (not within the scope of the invention)
[0053]
| |
Component |
Percent (by weight) |
| (3) |
Bentonite |
95.0 |
| |
Tripentaerythritol tetralaurate |
5.0 |
| |
|

|
| (3) Gel-forming and swelling sodium bentonite. |
[0054] A powdered product is made by blending together the indicated pentaerythritol oligomer
ester and the bentonite, and such may be agglomerated to particle size in the 10 to
100 sieve range, U.S. Sieve Series (which has openings 2.00 to 0.149 mm across) or
the powder may be used as is or suspended in water, with or without the presence of
emulsifying agent(s). The product is employed in the rinse water, with the concentration
of the PEC being the same as in Examples 1 and 2, and it is found that the composition
described has fabric softening properties like those of DSDMAC compositions containing
the same amount of quat as the ester content of such composition. Similar results
are obtainable when the other named satisfactory esters are substituted for the tripentaerythritol
tetralaurate. In all such cases the ester improves the fabric softening action of
the bentonite significantly. Additionally, when, in this example and in Examples 1
and 2, a silicone fabric softener, such as a dimethyl polysilicone or an aminosilicone,
is also present, its softening action is improved by the presence of the pentaerythritol
ester and dispersing agent.
[0055] In a variation of the formula of this example a dispersion of the tripentaerythritol
tetralaurate in water may be made by mixing together 20 parts of clay, 2 parts of
the pentaerythritol ester and 76 parts of water, with 2% of mixed emulsifier (the
mixture of Example 1) being optional (preferred).
[0056] The powder, agglomerate or emulsions of this example may be incorporated into any
suitable particulate detergent composition to make a softergent for use in the wash
water, or the liquid may be mixed with liquid detergent composition to make a liquid
softergent for use in washing. One may also employ the preparations in both the rinsing
and washing operations, which is often highly desirable.
[0057] When other monomeric pentaerythritol esters of the types described in this specification
are employed in the described compositions they usefully soften fabrics too, but it
is considered that the pentaerythritol distearate and pentaerythritol dipalmitate
are PECs that best represent the most effective, most readily available and most practicable
(from a commercial viewpoint) of these fabrics softeners in the described compositions.
[0058] The fabric softening effects described can also be obtained when the emulsifiers
employed are changed and when the proportions of fabric softening compound(s) and
emulsifier(s) are changed, within the ranges mentioned in this specification. Thus,
various other emulsifiers mentioned herein and in the McCutcheon publications, referred
to previously, may be substituted for those of the present examples and the favourable
results reported will be obtained. Similarly, aesthetic and functional adjuvants may
be present, such as perfumes, brighteners and others of the various adjuvants that
were mentioned previously, and the desired softening results are still obtainable.
[0059] What is surprising about these results is that the present compositions, which are
devoid of quaternary ammonium compound fabric softener, the acknowledged most effective
fabric softener presently known and in use, are fabric softening compositions of essentially
equal softening effectiveness (or nearly equal effectiveness in some cases) and do
not possess the undesirable properties of the quats (especially persistent toxicity
vs. aquatic organisms and an objectionable reactivity with anionic compounds), so
they can be used when and where quats are unacceptable. This is considered to be a
significant discovery and represents a substantial advance in the art.
EXAMPLE 4
[0060]
| Component |
% (by weight) |
| Sodium Linear dodecylbenzene sulfonate |
2.00 |
| Nonionic detergent (condensation product of one mol of C13-17 |
3.90 |
| mixed fatty type alcohols and 7 mols of EtO) |
|
| Stearyl hydroxyethyl imidazoline |
1.00 |
| Sodium silicate (Na2O:SiO2 = 1:2) |
4.00 |
| Sodium tripolyphosphate |
23.00 |
| Sodium carbonate (anhydrous) |
5.00 |
| Ethylenediamine tetra(methylene phosphonic acid), sodium salt |
0.38 |
| Stilbene type optical brightener |
0.21 |
| Methyl silicone (Dow-Corning X2-3302) |
0.18 |
| Sodium hydroxide |
1.00 |
| Sodium perborate tetrahydrate |
12.00 |
| Proteolytic enzyme (Alcalase® 2T) |
0.30 |
| Calcium montmorillonite (swellable in presence of sodium) |
16.00 |
| Potassium methyl siliconate |
0.50 |
| Hydroxylamine sulfate |
0.30 |
| Tetraacetyl ethylenediamine |
0.89 |
| Sodium aluminosilicate |
0.25 |
| Pentaerythritol distearate |
6.00 |
| Sodium sulfate, anhydrous |
13.59 |
| Perfume |
0.50 |
| Water |
9.00 |
| |

|
[0061] The particulate detergent composition described is made by roll drying (although
spray drying can also be used) a crutcher mix of various heat stable components, followed
by mixing the particulate product resulting with other powdered or particulate materials,
which can be those that are less heat resistant, and then perfuming the product. To
make the crutcher mix the components will usually be admixed with the water and any
sodium hydroxide that might be present, after which the other components will be admixed
in known manner so as to obtain the best mixing, following known mixing procedures.
After the crutcher mix is dried the base beads made by the drying process are then
blended with other components, such as perborate, clay (montmorillonite), preferably
bentonite, which may be in the calcium, sodium or other swellable form, enzyme(s),
hydroxylamine sulfate, sodium aluminosilicate and tetraacetyl ethylenediamine, and
then the mix may be perfumed.
[0062] The finished particulate softergent may then be packaged and marketed. When tested,
it shows a surprising improvement over softergents that are based on either clay fabric
softener alone or on PEC alone as the fabric softening component thereof and in comparative
softening tests the invented composition scores higher than the best commercial softergent
on the market. Similar desirable improvements in fabric softening detergent composition
is based on carbonate/zeolite built nonionic detergent formulations and when liquid
built detergents are those tested.
EXAMPLE 5
[0063] 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 4, 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.
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.
[0064] Nevertheless, the invented softergents soften the cotton (and other fabrics) about
as well as the quat rinse cycle softening compositions, which is an exceptional result.
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).
[0065] When the PEC is employed in fabric softening compositions and applications it has
been found that the presence with it of the suitable dispersing agent for it is of
great importance and greatly improves the fabric softening action of the PEC. In some
cases, such as with the zeolite/carbonate built nonionic synthetic organic detergent
compositions, the fabric softening can be increased from essentially nothing to excellent
when such a dispersing agent is present with the PEC. In other cases, such as with
the phosphate-built anionic detergent compositions the softening action may be increased
from fair to excellent, due to the presence of the dispersant. Such increase is significantly
more than any expected increase due to any fabric softening properties the dispersant
might possess. Thus, although PEC may be of fabric softening activity without the
presence of the dispersing agent, such action is significantly and unexpectedly increased
by the presence of such dispersant, which thereby increases the importance of the
invention.
The invention has been described with respect to various working examples and embodiments
but it is not to be considered to be limited to those because 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 of the invention as defined by the
appended claims.