Technical Field
[0001] The present invention relates to means of treating fibers and fabrics, wherein a
sub-stoichiometric complex of amines and phosphate esters is used to provide softness
and anti-static benefits. Detergent compositions containing said amine-phosphate ester
softeners are disclosed. The compositions herein can be used to soften fabrics.
Background
[0002] The use of softeners to treat fabrics after a washing operation is a well-known laundering
practice. Fabric softeners are, in the main, water-insoluble cationic materials that
are incompatible with anionic detersive surfactants used in most fabric washing compositions.
For that reason, the softening operation is generally carried out in the laundry rinse
bath after the surfactant has been removed from the washing machine. This entails
additional work for the user.
[0003] Formulators of fabric laundering compositions have long sought means whereby fabric
washing and softening could be done concurrently. Laundering methods employing clay
softeners, mixtures of clays and various amine materials and the like, are described
in the following patents: German 29/64114.3. 28/57163.3. 24/39541.3, 23/34899.4 and
EPO 80200570.2, 80200877.1 and 80201015.7. The use of mixtures of amines and soaps
(salt of fatty acids) as through-the-wash softeners is disclosed in U.K. Patent 1.514.276.
[0004] The prior art also discribes the use of various cationic materials in sheet form.
See U.S. Patent 4.220.562.
[0005] The prior art also teaches the softener use of alkyl phosphonate and quaternary ammonium
compounds. EPO Application 0 006 268, filed June 11, 1979.
[0006] The prior art also teaches various mixtures of phosphate esters in detergents with
fabric softening action - BE 802,679.
[0007] The present invention employs amine-phosphate ester softeners in laundry compositions
to provide cleaning and softening concurrently. The softeners herein provide softening
and anti-static benefits, especially when used with clay softeners. Importantly, the
use of phosphate esters in sub-stoichiometric quantities with the amines in the manner
disclosed herein advantageously enhances deposition of the amines on fabrics by as
much as 1.5- or 2-fold, as compared with prior art amine fabric softening compositions.
Summary of the Invention
[0008] The present invention encompasses a method for softening fabrics by contacting same
with sub-stoichiometric, water-insoluble, water-dispersible complexes of amine and
phosphate ester (as described more fully, hereinafter) in the presence of water. The
method can be carried out, for example, by tumbling damp fabrics with said complexes
in a hot air clothes dryer. In another mode, said complexes can be used in an aqueous
rinse bath, for example in a laundry rinse. In still another mode, the method can
be carried-out concurrently with a fabric cleansing treatment, for example in a detergent-containing
laundry liquor, to soften fabrics.
[0009] The invention also encompasses detergent compositions (preferably granular) which
may be described succinctly as containing conventional detergent ingredients such
as detersive surfactants (including anionics), detergency builders, optical brighteners,
detersive enzymes, fabric bleaches, and the like, all at rather conventional levels,
as well as clay fabric softeners (preferably, smectite clays), said compositions being
characterized in that they contain at least 0.1% (preferably 1.0% to 15%) of the aforesaid
sub-stoichiometric, water-insoluble, water-dispersible amine-phosphate ester softeners.
The most preferred compositions with clay are formulated to contain not more than
5% (preferably not more than 1%-2%) of a nonionic detersive surfactant.
[0010] The invention also encompasses an article for use in a laundry bath or rinse bath,
or in a laundry dryer, comprising the aforesaid sub-stoichiometric amine-phosphate
ester softeners releasably affixed to a water-insoluble carrier, for example, a sheet
of paper or fabric. Such compositions are optionally formulated to contain a bleach
activator and such activator-containing compositions are especially useful in laundry
baths.
[0011] The ingredients and means for preparing the compositions are disclosed more fully
hereinafter. All weights and proportions are by weight, unless otherwise specified.
Detailed Description of the Invention
[0012] As noted hereinafter, the compositions of this invention comprise, in major part,
conventional ingredients that are quite familiar to formulators of laundry compositions.
One of the major advantages of the amine-phosphate softeners used herein is that they
are entirely compatible with such conventional laundry ingredients, used at conventional
concentrations.
[0013] Amines - The amines employed herein are of the formula R
1R
2R
3N where
R1 is
C6 to C
20,
R2 is C
1 to C
20 or hydrogen, and R
3 is C
1 to C
10 or hydrogen. Preferably, the amines have both R
1 and R
2 as
C6-
C20 alkyl, with C
16-C
18 being most preferred, and with R
3 as C
1-C
3 alkyl. Mixed amines, such as dicoconutalkyl- and ditallowalkyl-methyl amines can
be used. Such materials are commercially available under Trade Marks such as "Armeen".
[0014] Phosphate Ester - The phosphate esters which are critical to the practice of this
invention are commercially available materials of the general formulae:

wherein R and R' are C
1-C
20 alkyl or (preferably) ethoxylated alkyl groups of the general formulae: alkyl-(OCH2CH2)Y,
wherein the alkyl substituent is
Cl-
C20' preferably C
8-C
16 and Y is an integer of 1 to 15, preferably 2-10, most preferably 2-5. Such compounds
are prepared by known methods from phosphorus pentoxide, phosphoric acid or phosphorus
oxy halide and alcohols or ethoxylated alcohols.
[0015] It will be appreciated that the formulae depicted represent mono- and di-esters,
and commercial phosphate esters will generally comprise mixtures of the mono- and
di-esters, together with some proportion of tri-ester. Typical commercial esters are
available under the Trade Marks "Phospholan" PDB3 (Diamond Shamrock) and "Servoxyl"
VPAZ (Servo).
[0016] Amine-Phosphate Ester Softeners - The prior art describes various phosphate ester-amine
compounds - see U.S. Patent 3.364.192 - some of which have been disclosed for use
as fiber-finishing agents - see U.S. Patents 3.434.874; 3.428.481; and 3.560.382.
However, the prior art compositions generally involve 1:1 (mole basis) compounds or
complexes, i.e., compounds or complexes from stoichiometric mixtures. Surprisingly,
such stoichiometric complexes are of no use in the present invention, apparently because
they form unstable dispersions prone to aggregation. In contrast, the sub-stoichiometric
mixtures herein are extremely well dispersed in water, but are not water-soluble.
[0017] While not intending to be limited by theory, it is instructive to consider the physico-chemical
behaviour of the amine-phosphate ester softeners herein, inasmuch as this can be of
assistance to the formulator.
[0018] It will be appreciated that the amines used herein and in art-disclosed compositions
exist in aqueous solutions as fairly coarse particles, or oily globules, having a
spectrum of sizes. It appears that attachment of such particles to fabrics to provide
the desired softening action can be considerably enhanced by reduction of their average
size: coarser material being rinsed away by mechanical action. On the other hand,
complete solubilization or micellization is to be avoided since this also leads to
inadequate attachment of the amine to fabrics.
[0019] In addition to size of the dispersed amine particles, their phase structure is of
importance since this will influence their effective spreading after attachment to
fiber or fabric surfaces. Phase structure influences also the stability of amine dispersions.
[0020] Consideration of these factors apparently explains why, on one hand, amines untreated
with phosphate ester and on the other hand, stoichiometric amine-ester complexes are
of very low effectiveness relative to the sub-stoichiometric mixtures of amine-phosphate
ester now disclosed.
[0021] It has now been discovered that sub-stoichiometric mixtures of amine-phosphate ester
exist as aqueous dispersions whose particles readily deposit on, spread on, and soften,
fibers and fabrics.
[0022] By "sub-stoichiometric" herein is meant that there is an excess of amine relative
to phosphate ester. In general, there are at least about two parts amine (on a weight
basis) per one part (weight) of phosphate ester, but this will, of course, vary with
the molecular weights of the amine and ester, respectively. The objective is to have
a readily-dispersible (in water) mixture, but not one that is water-soluble.
[0023] Useful amine-phosphate esters can easily be observed by a simple test. The amines
herein, suspended in water, form a generally greasy-appearing, non-homogeneous mixture.
By contrast, the sub-stoichiometric amine-phosphate ester mixtures used in this invention
form stable "milky" suspensions in water. Laboratory estimates of the particle sizes
of these suspensions indicate that 60% to 80% of the particles fall within the size
range of .1 to 8 micrometers; 20% to 40% within the range 8 to 20 micrometers; and
essentially all the particles are below 40 micrometers in diameter.
[0024] For the preferred sub-stoichiometric amine-phosphate ester softeners herein, the
weight ratio of amine:phosphate ester is above 5:1, generally 7:1 to 15:1, most preferably
10:1. Again, such softeners are selected to be water-dispersible, not water-soluble.
[0025] In general terms, the amine-phosphate ester softeners are prepared separately from
the balance of the compositions, and are preferably then added to the other, conventional
ingredients to provide the final formulations. This can most conveniently be done
by preparing a melt of the phosphate ester and the amine and maintaining the melt
stage for a few minutes. The melt can then be layered onto a sheet substrate to prepare,
for example, a dryer-added fabric softener. To prepare a detergent, the melt can be
solidified and comminuted to the desired particles size (e.g., in an extruder), and
dry-mixed with a granular detergent composition. The melt may also be sprayed onto
detergent granules. The melt may also be dispersed into a stirred, aqueous crutcher
mix comprising the balance of the detersive ingredients, and spray-dried in standard
fashion. This crutcher-addition is less preferred, as it leads to some decomposition
of the complex. Simply adding the amine and phospate ester, individually, to a detergent
crutcher mix does not secure the intended benefits of this invention.
[0026] An especially preferred softener herein is prepared by melting together ten parts
by weight of di-
C12-
C14 alkyl monomethyl amine and one part by weight of a mono - [C
12-C
14 (EO)
1-5] ester of phosphoric acid, sold under the Trade Mark "Servoxyl VPAZ".
[0027] The amine-phosphate ester softeners will generally be used at levels of at least
0.1%, preferably 1% to 15%, in detergent compositions; at levels of at least 1%, preferably
1% to 25% in rinse-added fabric softeners; and at levels of 2% to 60% in dryer- and
wash machine- added sheets (where the balance of the composition mainly comprises
the weight of the sheet substrate).
[0028] Softener Clay - The above-disclosed amine-phosphate ester softeners are preferably
used in granular detergent compsitions, where they are most preferably used in combination
with a detergent-compatible clay fabric softener. Such clay softeners are well-known
in the detergency patent literature and are in broad commercial use, both in Europe
and in the United States. Included among such clay softeners are various heat-treated
kaolins and various multi-layer smectites. Preferred clay softeners are smectite softener
clays that are described in German patent document 23 34 899 and in U.K. Patent 1.400.898
which can be referred to for details. Softener clays are used in the preferred compositions
at levels of at least 1%, generally 1-20%, preferably 2-7%.
[0029] Detersive Surfactants - The detergent compositions of this invention will contain
organic surface-active agents ("surfactants") to provide the usual cleaning benefits
associated with the use of such materials.
[0030] Detersive surfactant useful herein include well-known synthetic anionic, amphoteric
and zwitterionic surfactants. Typical of these are the alkyl benzene sulfonates, alkyl-
and alkylether sulfates, paraffin sulfonates, olefin sulfonates, amine oxides, ol
-sulfonates of fatty acids and of fatty acid esters, and the like, which are well-known
from the detergency art. In general, such detersive surfactants contain an alkyl group
in the C
9-C
18 range; the anionic detersive surfactants can be used in the form of their sodium,
potassium or triethanolammonium salts. U.S. Patent 4.111.855 contains detailed listings
of such typical detersive surfactants. CI1-C16 alkyl benzene sulfonates, C
12-C
18 paraffin-sulfonates and alkyl sulfates are especially preferred in the compositions
of the present type.
[0031] Also useful herein as the surfactant are the water-soluble soaps, e.g. the common
sodium and potassium coconut or tallow soaps well-known in the art.
[0032] It is to be understood that the use of typical alkoxylated nonionic surfactants (e.
g. the C
9-
C18 alkyl) alcohols and alkyl phenols with 5 to 20 ethoxyl groups) are preferably limited
in the practice of this invention to levels of not more than about 5%, preferably
not more than 2%, most preferably 0-1%, of the compositions when clay is present as
a co-softener, since alkoxylates can interfere with the softening properties of clay.
In clay-free compositions, the alkoxylated nonionics can be used at any desired level.
[0033] The surfactant component can comprise as little as 1% of the laundry detergent compositions
herein, but generally the compositions will contain 5% to 40%, preferably 6% to 30%,
of surfactant. Mixtures of the anionics, such as the alkyl benzene sulfonates. alkyl
sulfates and paraffin sulfonates are preferred for through-the-wash cleansing of a
broad spectrum of soils and stains from fabric.
[0034] Detersive Adiuncts - The compositions herein can contain other ingredients which
aid in their cleaning performance. For example, it is highly preferred that through-the-wash
detergent compositions contain a detergent builder and/or metal ion sequestrant. Compounds
classifiable and well-known in the art as detergent builders include the nitrilotriacetates,
polycarboxylates, citrates, water-soluble phosphates such as tri-polyphosphate and
sodium ortho- and pyro-phosphates, silicates, and mixtures thereof. Metal ion sequestrants
include all of the above, plus materials like ethylene diaminetetraacetate, the amino-polyphosphonates
and phosphates (DEQUEST) and a wide variety of other poly-functional organic acids
and salts too numerous to mention in detail here. See U.S. Patent 3.579.454 for typical
examples of the use of such materials in various cleaning compositions. In general,
the builder/sequestrant will comprise 0.5% to 45% of the composition. The 1-10 micrometer
size zeolite (e.g. zeolite A) builders disclosed in German Patent 24 22 655 are especially
preferred for use in low-phosphate compositions which contain the softeners described
herein.
[0035] The laundry compositions herein also preferably contain enzymes to enhance their
through-the-wash cleaning performance on a variety of soils and stains. Amylase and
protease enzymes suitable for use in detergents are well-known in the art and in commercially
available liquid and granular detergents. Commercial detersive enzymes (preferably
a mixture of amylase and protease) are typically used at levels of 0.001% to 2%, and
higher, in the present compositions.
[0036] Moreover, the compositions herein can contain, in addition to ingredients already
mentioned, various other optional ingredients typically used in commercial products
to provide aesthetic or additional product performance benefits. Typical ingredients
include pH regulants, perfumes, dyes, bleaches, optical brighteners, soil suspending
agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides,
preservatives, suds control agents, bleach activators and the like.
[0037] The compositions can further contain a peroxygen bleach activator, particularly tetraacetyl
ethylenediamine (TAED), typically from 0.1% to 5%, preferably from 0.5% to 2.5%. Other
highly desirable detergent ingredients for use in the detergent compositions of the
present invention are quaternary ammonium compounds of the form R
4R
3R
6R
7N
+X
-, wherein R
4 is alkyl having from 10 to 20, preferably from 12-18 carbon atoms, and R
5,R
6 and R
7 are each C
1 to C
4 alkyl preferably methyl: X is an anion, e.g. chloride. Examples of such quaternary
ammonium compounds include monotallowalkyl trimethyl ammonium chloride and mono(cocoalkyl)
trimethyl ammonium methosulfate. The quaternary ammonium compounds can be used at
levels from 0.5% to 5%, preferably from 1% to 3%. Detergent compositions containing
both TAED and the mono(long chain alkyl) tri(short chain alkyl) ammonium compound
are highly preferred.
[0038] In a through-the-wash laundry mode, the compositions are typically used at a concentration
of at least 500 ppm, preferably 0.10% to 2.5%, in an aqueous laundry bath at pH 7-11
to launder fabrics. The laundering can be carried out over the range from 5°C to the
boil, with excellent results.
[0039] In an alternate mode, the amine-phosphate ester softeners herein may be releasably
adsorbed or releasably coated onto a non-particulate substrate such as a non-woven
or paper sheet or flexible sponge mat, or the like. Such sheet-form objects may be
added to the laundry or rinse bath, or to the laundry dryer, where the softener is
released to provide fabric softening. In an alternate, and highly preferred, mode
the amine-phosphate ester softener is used in sheet form in combination with a bleach
activator (such as tetraacetyl ethylene diamine or a straight- or branched-chain C
6-C
10 oxybenzene sulfonate) as a combined perborate-activator and softener in a laundry
liquor. See, for example U.S. Patent 4.220.562.
[0040] Such sheet-form products will generally employ 1-20 grams of the amine-phosphate
ester softener and 1-20 grams of the bleach activator.
[0041] In still another mode, the amine-phosphate ester can be formulated as a liquid fabric
softener and used in a post-laundry rinse bath. Such liquid softeners can comprise,
for example, a simple dispersion of the amine-phosphate ester softener in water or
water-alcohol.
[0042] It is to be understood that the compositions and processes of this invention are
carried out in a manner that will, typically, deposit at least a few milligrams (generally,
at least 1-1000 mg) of the sub-stoichiometric amine-phosphate ester softener per square
meter on the fabric being treated, as will be seen in the following examples.
INDUSTRIAL APPLICATION
[0043] The following examples are typical of the preferred compositions of this invention,
but are not intended to limit the scope of the invention.
EXAMPLE I
[0044] A mix of ditallow methyl amine (total 3.8% of complete formulation after spray-drying)
and
monococonutalkyl(ethoxy)1-5 phosphoric acid ester (0.38% of complete formulation)
are admixed, melted in a jacketed bath, and maintained as a melt for about ten minutes.
Stirring assures homogeneity.
[0045] A standard aqueous crutcher mix comprising the following ingredients is prepared
(percentages listed relate to percent ingredients in the complete formulation after
spray-drying).

[0046] The crutcher mix is handled in entirely standard fashion, and spray-dried to form
a granular composition.
[0047] The amine-phosphate ester softener is added to the spray-dried granules as particles
or "prills".
[0048] The composition of Example I is free-flowing and provides excellent cleaning and
through-the-wash fabric softening when used at laundry concentration of 0.1% and above.
[0049] In an alternate mode, the amine-phosphate ester softener can be sprayed onto the
spray-dried granules.
[0050] The composition of Example I may be modified by adding 1.0% tetraacetyl ethylenediamine
(TAED) as a perborate bleach activator. It is preferred that materials such as bleach
activators and enzymes be dry-mixed with the balance of the composition, after spray-drying.
[0051] The composition may be modified further by adding, in addition to TAED, 2.4% monotallowalkyl
trimethyl ammonium chloride.
EXAMPLE II
[0052] A low-P spray-dried detergent formulation is as follows :

[0053] The composition of Example II is prepared by spray-drying an aqueous crutcher mix,
in the manner described for Example I. In use, the composition gives excellent cleaning
and through-the-wash fabric softening performance.
EXAMPLE III
[0054] A clay-free composition is prepared by removing the clay from Example I and substituting
therefor an additional softener comprising monotallowalkyl trimethyl ammonium chloride
as 2.4% of the total composition.
EXAMPLE IV
[0055] A laundry additive product is prepared by warming 6.5g of bis(tetradecyl)methyl amine
and 0.8g of tetradecylphosphate to form a melt, and spreading the melt onto an ordinary
disposable paper hand-towel (20x20 cm). 4 grams of TAED powder (1-10 microns) are
sprinkled onto, and pressed into, the melt before it has the chance to solidify.
[0056] The article of Example IV is added to a laundry liquor containing a commercial perborate/clay
detergent composition (DASH-3; Trade Mark) to enhance through-the-wash softening and
bleaching performance.
EXAMPLE V
[0057] The article of Example IV is modified by deleting the TAED and replacing the Example
IV softener with 3.5g. of the amine-phosphate ester softener of Examples I and II.
The resulting article is tumbled with damp fabrics in a standard hot air clothes dryer,
whereby the softener is transferred to the fabrics to impart softness.
EXAMPLE VI
[0058] A fine-fabric laundering composition with fabric softening properties is as follows
:

[0059] The composition of Example VI is in the form of a "milky" liquid.
1. A method of softening fabrics which comprises contacting said fibres or fabrics
with a sub-stroichiometric, water-dispersible amine-phosphate ester softener in the
presence of water.
2. A method according to Claim 1 which is carried-out in an aqueous laundry liquor.
3. A method according to Claim 1 which is carried-out by tumbling damp fabrics with
said amine-phosphate ester softener in a hot air clothes dryer.
4. A laundry detergent composition comprising conventional detersive ingredients,
characterized in that it contains at least 0.1% of a sub-stroichiometric, water-dispersible
amine-phosphate ester softener.
5. A composition according to claim 4 which contains from 1% to 15% of said amine-phosphate
ester softener.
6. A composition according to Claim 5 which also contains at least 1% of a clay fabric
softener.
7. A composition according to Claim 6 which contains not more than 5% of an alkoxylated
nonionic detersive surfactant.
8. A composition according to any of Claims 4 through 7 which contains a detergency
builder selected from phosphate, nitrilotriacetate, polycarboxylate, citrate and zeolite
builders, or mixtures thereof.
9. A composition according to any of the Claims 4 through 8 which contains from 0.1%
to 5% TAED and from 0.5% to 5% of a quaternary ammonium compound of the formula R4R5R6R7N+X- , wherein R4 is alkyl having from 10 to 20 carbon atoms, R5,R6 and R7 are each alkyl having from 1 to 4 carbon atoms, and X- is an anion.
10. An article for use in a laundry or rinse bath, or in a laundry dryer, comprising
a non-particulate substrate, preferably a flexible sheet, having releasably affixed
thereto a fabric softener which comprises a sub-stoichiometric, water-dispersible
amine-phosphate ester fabric softener.
11. An article according to Claim 10 which additionally has affixed thereto a bleach
activator.
12. A composition of matter comprising a water-insoluble, water-dispersible mixture
or melt of a phospate ester and an alkyl amine, at a weight ratio of amine:phosphate
ester of at least 2:1.