Technical Field
[0001] This invention relates to compositions which provide static control benefits in fabric
laundering operations. More particularly, it relates to providing these benefits at
reduced antistatic agent levels while simultaneously cleansing fabrics by means of
conventional detergent compositions and detergency builders.
Background Art
[0002] Various quaternary ammonium compounds are known in the art to possess antistatic
properties. These quaternary ammonium compounds are also known to be generally incompatible
with anionic surfactants commonly employed in laundering compositions. The anionic
surfactants attack and inactivate the quaternary ammonium compounds in the wash-water
environment. Thus, larger amounts than desired of the fairly expensive quaternary
ammonium compounds must be added to detergent. compositions in order to avoid total
inactivation in wash solution. It therefore would be highly beneficial, from a performance
and economic standpoint, to be able to shield the quaternary ammonium compounds in
the wash water, without disturbing their effectiveness as static control agents in
the subsequent machine drying process.
[0003] Techniques known in the art for preserving the antistatic properties of the quaternary
ammonium compounds, such as the prilling of the quaternary ammonium compound with
organic dispersion inhibitors, as disclosed in U.S. Patent 3,936,537, Baskerville
et al, issued February 3, 1976, incorporated herein by reference, and the agglomeration
of that prill with certain water-soluble neutral or alkaline salts, using organic
agglomerating agents, as disclosed im U.S. Patent 4,141,841, McDanald, issued February
27, 1979, incorporated herein by reference, while delivering improved static control
and softening benefits over methods then known in the art, were only partially effective.
Some of the quaternary ammonium compound continued to be inactivated by the anionic
surfactants, and some of the prills continued to be broken up and dispersed in the
wash water, preventing the efficient deposition of antistatic materials of an effective
size range onto the fabrics to be treated. The above-described techniques still required
the addition of larger quantities of the quaternary ammonium compound than necessary
to achieve good static control in the absence of the detergent. Also the conventional
organic agglomerating agents, such as dextrin glue solutions, required in McDanald
to agglomerate the prills with the salts could cause poor caking characteristics and
flowability problems in the detergent product under certain conditions, making handling
and packaging difficult at times.
[0004] The present invention, by contrast, teaches the deliberate pre-wash-water complexing
of certain anionic components with the quaternary'ammonium compounds to deliver superior
static control at significantly reduced levels of antistatic material. The Baskerville
et al and McDanald references attempted to avoid the interaction of anionic components
with the quaternary ammonium compound upon which the present invention is based. Further,
it has been discovered that water can act as the agglomerating agent and/or the complexing
medium, while producing a product with at least equivalent caking characteristics,
and even superior caking qualities under certain conditions. Thus, the organic agglomerating
agents required in McDanald have been eliminated in the present.invention, reducing
material costs and eliminating extra processing and handling steps.
[0005] It is an object of the present invention to provide a particulate detergent additive
composition which delivers static control and fabric-softening benefits to laundered
fabrics while using a minimum amount of antistatic/softening agent. It is also an
object of the present invention to provide a detergent composition capable of concurrently
laundering, softening, and imparting static control benefits to fabrics washed therewith
and subsequently machine dried.
Summary of the Invention
[0006] The present invention encompasses a particulate detergent additive for preventing
static buildup on textiles and for softening fabrics when applied thereto from a laundry
solution, the additive comprising a quaternary ammonium compound of formula [R
1R
2R
3R
4N]+Y wherein at least one, but not more than two, of R
1, R
2, R3, and R
4 is an organic radical containing a group selected from a C
16-C
22 aliphatic radical, or an alkyl phenyl or alkyl benzyl radical having 10 to 16 carbon
atoms in the alkyl chain, the remaining group or groups being selected from C
1-C
4 alkyl,
C2-
C4 hydroxyalkyl, and cyclic structures in which the nitrogen atom forms part of the
ring, Y constituting an anionic radical selected from the group consisting of hydroxide,
halide, sulfate, methylsulfate, ethylsulfate and phosphate ions, and optionally an
organic dispersion inhibitor being a solid organic material having a solubility in
water of 50 ppm maximum at 25°C and a softening point in the range of 75°F to 250°F,
said material being selected from the group consisting of paraffinic waxes, cyclic
and acyclic mono-and polyhydric alcohols, substituted and unsubstituted aliphatic
carboxylic acids, esters of the foregoing -alcohols and acids, C
3-C
4 alkylene oxide condensates of any of the foregoing materials and mixtures thereof;
wherein substantially all of the particles have a size of about 10 microns to about
500 microns, a solubility in water of about 50 ppm maximum at 25°C, and a softening
point of from about 75°F to about 250°F wherein the particulate additive comprises
a complex comprising
(a) from 10-99% by weight of the additive of the quaternary ammonium compound; and
(b) from 1% to 90% by weight of an anionic complexing component selected from the
group consisting of. anionic synthetic surfactants, soaps, nonsurfactant electrolytes
selected from the group consisting of alkali metal phosphates, borates, carbonates,
silicates, sulfates, and citrates; and mixtures of any of the foregoing;
wherein said complex constitues at least 25% of the surfaces of said particulate additive.
[0007] Preferably the complex constitutes 50%-100% of the surface of the particulate additive
and most preferably the anionic complexing component complexes substantially all of
the quaternary ammonium compound. In a particularly preferred embodiment the quaternary
ammonium compound and optionally the dispersion inhibitor are in admixture with a
particulate anionic complexing component, which preferably is sodium tripolyphosphate.
The invention also embraces a detergent composition incorporating from 3% to 50% by
weight of the particulate detergent additive together with from 5% to 85% by weight
surfactant selected from the group consisting of anionic, nonionic, ampholytic, and
zwitterionic surfactants, and mixtures thereof, and from 5% to 85% by weight of detergency
builder material.
Disclosure of the Invention
[0008] This invention comprises the deliberate, pre-wash-water complexing of quaternary
ammonium compounds with certain anionic complexing components to deliver superior
static control at significantly reduced levels of antistatic material. The antistatic
particles of the present invention are formed by the at least partial complexing of
the cationic quaternary ammonium compound with the anionic complexing components.
The complex formed should constitute at least 25% of the surfaces of the antistatic
particles. More preferably, the complex constitutes at least 50% of the surfaces,
and most preferably the complex constitutes substantially all the surfaces of the
antistatic particles. The reaction can also result in the complexation of.substantially
all of the quaternary ammonium compound, although it is preferred that the complexing
be limited to the surfaces of the antistatic particles. While not intending to be
limited by theory, it is believed that the present antistatic particles deliver static
control advantages because they are less susceptible to wash-water penetration and
breakup than the uncomplexed quaternary ammonium particles, thereby allowing for a
more efficient deposition of antistatic material-of an effective size range and composition
onto the laundered fabrics. The complexed material, which is relatively water-impermeable
and water-insoluble, separates unreacted quaternary ammonium antistatic material from
the wash-water environment and thus hinders the inactivation of this antistatic material
by anionic surfactants. Further, the complex itself may provide some additional static
control of its own to the system. Thus, the anionic complexing component should be
chosen, in view of the particular cationic antistatic agent used, to achieve such
a water-impenetrable and insoluble complex. The complexing components should also
be chosen to maximize the antistatic properties of the complex itself.
[0009] In a particularly preferred embodiment of -the present invention, the antistatic
particles additionally contain an organic dispersion inhibitor which is intimately
mixed with the quaternary ammonium compound and formed into a prill prior to the complexing
reaction. The dispersion inhibitor adds to the water-impenetrability and insolubility
of the complex formed and thus enhances the antistatic benefits realized from the
present invention.
[0010] As another preferred embodiment, a mixture of anionic complexing components is used.
Especially preferred are mixtures of sodium tripolyphosphate (STP) with the other
complexing components described herein. Such a mixture, with several possible participating
complexing components, can assist in the formation of the desired complex. Further,
anionic complexing components which are water-soluble neutral or alkaline salts, especially
STP, can absorb excess moisture making the particulate detergent additive stronger
and more free-flowing.
[0011] The additive products of the present invention can be admixed or agglomerated with
smectite clays to enhance fabric softening, and the detergent composition of this
invention can additionally contain water-soluble detergency compounds and detergency
builder salts. The quaternary ammonium compound provides antistatic benefits on the
fabrics and also adds an increment of softening benefit to the fabrics, while the
detergent surfactant and builder components provide known cleansing and building benefits.
[0012] The individual particle size of the particulate detergent additive lies in the range
from about 10 microns to 500 microns, preferably from about 25 microns to about 250
microns, and most preferably from about 50 microns to about 100 microns. Further,
the particulate additive should not have a solubility in water at 25°C of greater
than 50 ppm (parts per million), preferably less than 10 ppm. The softening or melting
point of the particulate additive should lie in the range from about 100
0F to about 250°F, preferably from about 100°F to about 200°F, more preferably from
about 150°F to about 175°F. The above specified ranges need not apply to complexed
quaternary ammonium compound particles free of the organic dipsersion inhibitor material,
although the ranges preferably also apply in this situation. Individual particles
of the particulate detergent additive can become agglomerated during processing steps.
These agglomerates have a size of from about 10 microns to about 2500 microns. The
agglomerates break-up in the wash water, but the individual particles remain relatively
water-impenetrable and insoluble.
Anionic Complexing Component
[0013] The anionic complexing component required to form the complex is selected from the
group consisting of anionic synthetic surfactants; soaps; nonsurfactant electrolytes
selected from the group consisting of alkali metal orthophosphates, polyphosphates,
borates, tetraborates, silicates, sulfates, and citrates; and mixtures thereof. The
anionic component represents from about 1% to about 90% by weight, more preferably
from about'5% to about 60% by weight, of the particulate detergent additive. The anionic
component is preferably reacted with the quaternary ammonium antistatic agent, or
antistatic agent/dispersion inhibitor mixture, as a solution (preferably a water solution)
which comprises from about 1% to about 80% by weight, preferably from about 5% to
about 50% by weight of the anionic component. Preferably, the anionic complexing component
is present in such a solution at a concentration close to its saturation point. The
anionic complexing solution is preferably sprayed onto the quaternary ammonium compound
itself, or onto prills, agglomerates or admixes containing it. A fluidized bed reactor
can also be used to contact the anionic solution with the quaternary compound particles
or prills. The anionic complexing component can optionally be admixed as a solid with
the quaternary ammonium compound before being complexed, preferably by being sprayed
with a complexing medium, such as water or an aqueous complexing solution.
[0014] Nonsurfactant electrolytes suitable as the anionic complexing component include alkali
metal phosphates, borates', carbonates, silicates, sulfates, citrates, and mixtures
thereof. Preferred are sodium tetraborate, potassium tetraborate, sodium tripolyphopshate,
potassium tripolyphosphate, sodium pyrophosphate, potassium pyrophosphate, sodium
hexametaphosphate, potassium hexametaphosphate, sodium sulfate, potassium sulfate,
sodium citrate, potassium citrate, and mixtures thereof. Especially preferred are
sodium tripolyphosphate, sodium sulfate, and mixtures thereof.
[0015] Water-soluble salts of the higher fatty acids, i.e. "soaps', are useful as the anionic
complexing component herein. Suitable are ordinary alkali metal soaps such as the
sodium, potassium, ammonium, and alkanolammonium salts of higher fatty acids containing
from about 8 to about 24 carbon atoms and preferably from about 10 to about 20 carbon
atoms. Soaps can be made by direct saponification of fats and oils or by the neutralization
of free fatty acids. Particularly useful are the sodium and potassium salts of the
mixtures of fatty acids derived from coconut oil and tallow, i.e., sodium or potassium
tallow and coconut soaps.
[0016] Anionic synthetic surfactants useful as a complexing component herein include water-soluble
salts, particularly the alkali metal, ammonium and alkanolammonium salts, of organic
sulfuric reaction products having in their molecular structure an alkyl group containing
from about 8 to about 22 carbon atoms and a sulfonic acid or sulfuric acid ester-group.
(Included in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this
group of synthetic surfactants which can be used in the present invention are the
sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher
alcohols (C
8-C
18 carbon atoms) produced by reducing the glycerides of tallow or coconut oil; sodium
or potassium C
8-C
20 paraffin sulfonates; and sodium and potassium alkyl benzene sulfonates, in which
the alkyl group contains from about 9 to about 15 carbon atoms in straight chain or
branched chain configuration, e.g., those of the type described in U.S. Patents 2,220,099
and 2,477,383, incorporated herein by reference.
[0017] Other anionic surfactant compounds useful herein include the sodium alkyl glyceryl
ether sulfonates, especially those ethers of higher alcohols derived from tallow and
coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates;
and sodium or potassium salts of alkyl phenol ethylene oxide ether sulfate containing
about 1 to about 10 units of ethylene oxide per molecule and wherein the alkyl groups
contain from about 8 to about 13 carbon atoms.
[0018] Other useful anionic surfactants herein include the water-soluble salts of esters
of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the
ester group; water-soluble salts of 2-acyloxy-alkane-l-sulfonic acids containing from
about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms
in the alkane moiety; alkene sulfonates containing from about 10 to 20 carbon atoms
in the alkane group; and beta-alkyloxy alkane sulfonates containing from about 1 to
3 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane
moiety.
[0019] Other useful anionic surfactants utilizable herein are olefin sulfonates having about
12 to about 24 carbon atoms. The term "olefin sulfonates" is used herein to mean compounds
which can be produced by the sulfonation of alpha-olefins by means of uncomplexed
sulfur trioxide, followed by neutralization of the acid reaction mixture in conditions
such that any sulfones which have been formed in the reaction are hydrolyzed to give
the corresponding hydroxyalkane sulfonates. The sulfur trioxide can be liquid or gaseous,
and is usually, but not necessarily, diluted by inert diluents for example by liquid
SO
2' chlorinated hydrocarbons, etc., when used in the liquid form, or by air, nitrogen,
gaseous S0
2, etc., when used in the gaseous form.
[0020] The alpha-olefins from which the olefin sulfonates are derived are mono-olefins having
12 to 24 carbon atoms preferably 14 to 16 carbon atoms. Preferably they are straight
chain olefins.. Examples of suitable 1-olefins include 1-dodecene, 1-tetradecene,
1-hexadecene, 1-octadecene, 1-eicosene, and 1-tetracosene.
[0021] In addition to the true alkene sulfonates and a portion of hydroxyalkane sulfonates,
the olefin sulfonates can contain minor amount of other materials, such as alkene
disulfonates depending upon the reaction conditions, proportions ofreactants, the
nature of the starting olefins and impurities in the olefin stock and side reactions
during the sulfonation process.
[0022] Preferred anionic synthetic surfactants are alkali and alkaline earth metal, ammonium
and alkanol ammonium salts of linear and branched C
10-C
14 alkyl benzene sulfonates, C
10-C
20 alpha-sulfo carboxylic acid salts and esters in which the alkyl group has 1-8 carbon
atoms, C
10-C
20 alkane sulfonates, C
14-C
18 olefin sulfonates,
C10-
C18 alkyl sulfates and mixtures thereof.
[0023] The preferred group of anionic complexing components for use herein includes sodium
tetraborate, potassium tetraborate, sodium tripolyphosphate, potassium tripolyphosphate,
sodium pyrophosphate, potassium pyrophosphate, sodium hexametaphosphate, potassium
hexametaphosphate, sodium sulfate, potassium sulfate, sodium citrate, potassium citrate,
C
10-C
14 linear and branched alkyl benzene sulfonates, C
10-C
18 alkyl sulfates, and mixtures thereof. Especially preferred anionic complexing components
are sodium tripolyphosphate, sodium sulfate, C
10-C
14 linear and branched alkylbenzene sulfonates, and mixtures thereof.
Quaternary Anunonium Antistatic Agent
[0024] The cationic component of the present invention is a quaternary ammonium antistatic
agent, which will be employed in the particulate detergent additive in an amount from
about 10% to about 99% by weight, preferably from about 20% to about 75% by weight,
more preferably from about 30% to about 60% by weight. Suitable quaternary ammonium
antistatic agents are included in U.S. Patent 3,936,537, Baskerville et al, which
has been incorporated hereinabove by reference. In the preferred embodiment of the
present invention where the quaternary ammonium compound is intimately mixed with
an organic dispersion inhibitor and formed into a prill prior to the complexing reaction,
the quaternary ammonium antistatic agent will normally be employed at a level of from
about 90% to about 20% by weight, and more preferably from about 80% to about 50%
by weight, of the intimate mixture.
[0025] The antistatic agents useful herein are quaternary ammonium salts of the formula
[R
1R
2R
3R
4N]+Y wherein R
1 and preferably R
2 represent an organic radical or an alkyl phenyl or alkyl benzyl radical having 10-16
atoms in the alkyl chain, R
3 and R
4 represent hydrocarbyl groups containing from 1 to about 4 carbon atoms, or C
2-C
4 hydroxy alkyl groups and cyclic structures in which the nitrogen atom forms part of
the ring, and Y is an anion such as halide, methylsulfate, or ethysulfate.
[0026] In the context of the above definition, the hydrophobic moiety (i.e., the C
16-C
22 aliphatic, C
10-C
16 alkyl phenyl or alkyl benzyl radical) in the organic radical Rl may be directly attached
to the quaternary nitrogen atom or may be indirectly attached thereto through an amide,
esters, alkoxy, ether, or like grouping.
[0027] The quaternary ammonium antistatic agents used in this invention can be prepared
in various ways well known in the art. Many such materials are commercially available.
The quaternaries are often made from alkyl halide mixtures corresponding to the mixed
alkyl chain lengths in fatty acids. For example, the "ditallow" quaternaries are made
from alkyl halides having mixed C
14-C
18 chain lengths. Such mixed di-long chain quaternaries are useful herein and are preferred
from a cost standpoint. As used herein "ditallow" is intended to refer to the above-described
ditallowalkyl quaternaries.
[0028] The quaternary ammonium antistatic compounds useful herein include both water-soluble
and substantially water-insoluble materials. Imidazolinium compounds enumerated in
the Baskerville patent, possess appreciable water solubility and can be utilized in
the present invention by mixing with the appropriate type and level of organic dispersion
inhibitor and complexing component to give ultimate particle solubility in water of
less than 50 ppm (parts per million) at 25°C. Relatively water-soluble quaternary
ammonium antistatic agents may also be of the non-ring variety, such as diisostearyl
dimethyl ammonium chlorides disclosed in U.S. Patent 3,395,100 to Fisher et al, incorporated
herein by reference. Exemplary quaternary ammonium imidazolinium compounds are specifically
methyl-l-alkylamidoethyl-2-alkyl imidazolinium methyl sulfates, specifically 1-methyl-1-[(tallowamido)ethyl]-2-
tallowimidazolinium methyl sulfate. However, the most useful quaternary ammonium antistatic
agents are characterized by relatively limited solubility in water.
[0029] The following are representative examples of substantially water-insoluble quaternary
ammonium antistatic agents suitable for use in the compositions of the instant invention.
All of the quaternary ammonium compounds listed can be formulated with the detergent
compositions herein, but the compilation of suitable quaternary compounds hereinafter
is only by way of example and is not intended to be limiting of such compounds. Dioctadecyl-
dimethyl ammonium chloride is an especially preferred quaternary antistatic agent
for use herein by virtue of its high antistatic activity; ditallow dimethyl ammonium
chloride is equally preferred because of its ready availability and its good antistatic
activity; other useful di-long chain quaternary compounds are dicetyl dimethyl ammonium
chloride; bis-docosyl dimethyl ammonium chloride; didodecyl dimethyl ammonium chloride;
ditallow dimethyl ammonium bromide; dioleoyl dimethyl ammonium hydroxide; ditallow
dimethyl ammonium chloride; ditallow dipropyl- ammonium bromide; ditallow dibutyl
ammonium fluoride; cetyldecylmethylethyl ammonium chloride; bis-[ditallow dimethyl
ammonium] sulfate; tris-[ditallow dimethyl ammonium] phosphate; and the like.
[0030] The preceding description of quaternary ammonium antistatic compounds is an abbreviated
discussion. Description in further detail is contained in the Baskerville et al patent.
Organic Dispersion Inhibitor
[0031] As a preferred embodiment of the present invention, the particulate detergent additive
contains an organic dispersion inhibitor which is intimately mixed with the quaternary
ammonium compound in the form of a prill prior to the complexing reaction. The organic
dispersion inhibitor adds to the water-impenetrability and insolubility of the complex
formed and thus enhances the anti- static benefits realized from the present invention.
The organic dispersion inhibitor represents from about 10% to about 80% by weight,
more preferably from about 20% to about 50% by weight, of the intimate mixture. The
intimate mixture represents from about 10% to about 99%, -preferably from about 20%
to about 90%, most preferably from about 30% to about 70% by weight of the particulate
detergent additive. The dispersion inhibitor should have a solubility in water of
50 ppm maximum at 25
0C and a softening point in the range of 100 -200°F, preferably 125°-200°F, and is
preferably selected from the group consisting of paraffinic waxes, cyclic and acyclic
mono-and polyhydric alcohols, substituted and unsubstituted aliphatic carboxylic acids,
esters of the foregoing alcohols and acids, C.
3-C
4 alkylene oxide condensates of any of the foregoing materials and mixtures thereof.
[0032] Tallow alcohol is preferred because of ready availability, but useful dispersion
inhibitors include other fatty alcohols in the C
14-C
26 range, such as myristyl alcohol, cetyl alcohol, stearyl alcohol, arachidyl alcohol,
behenyl alcohol, and mixtures thereof. Saturated fatty acids having 12 to 24 carbon
atoms in the alkyl chain can be used, such as: lauric acid, myristic acid, palmitic
acid, stearic acid, arachidic acid, and behenic acid, as well as mixtures of these,
particularly those derived from naturally occurring sources such as tallow, coconut,
and marine oils. Esters of the aliphatic alcohols and fatty acids are useful dispersion
inhibitors, provided they have a total of more than 22 carbon atoms in the acid and
alkyl radicals. Long chain C
22-C
30 paraffinic hydrocarbon materials such as the saturated hydrocarbon octacosane having
28 carbon atoms can also be used. When fatty acids are used as dispersion inhibitors
as hereinabove described, the anionic complexing component may not include soaps,
which are more fully described above.
[0033] Another preferred class of materials useful in the present invention are the water-insoluble
sorbitan esters which comprise the reaction product of C
12-C
26 fatty acyl halides or fatty acids and the complex mixtures of cyclic anhydrides of
sorbitol collectively known as "sorbitan". The reaction sequence necessary to produce
such sorbitan esters from sorbitol is set out in the Baskerville patent incorporated
by reference. The sorbitan esters are, in turn, complex mixtures of mono, di-, tri-,
and tetra-ester forms, of which the tri- and tetra- are the least water-soluble and
hence the most preferred for the purposes of the present invention. Typical fatty
acids that are suitable for the alkyl portion of the ester are palmitic, stearic,
docosanoic, and behenic acids and mixtures of any of these. These sorbitan esters,
particularly the tri- and tetra-esters, provide a degree of fabric softening in addition
to their function as dispersion inhibitors.
[0034] The previous discussion of organic dispersion inhibitors is an abbreviated one.'
Further discussion in detail is set out in the Baskerville et al patent.
Water-Soluble, Neutral or Alkaline Salt
[0035] As another preferred embodiment of the present invention, mixtures of anionic complexing
components are used in forming the particulate detergent additives.
[0036] These mixtures can be formed into a solution and sprayed onto the quaternary ammonium
compound forming the desired complex, or, one of the complexing components, preferably
a water-soluble neutral or alkaline salt, is added to the system as a solid prior
to complexing with a solution of the remaining complexing component. The salt can
assist in the formation of the complex, thus enhancing.the benefits realized from
its formation, and it can itself complex with the quaternary ammonium compound. Further,
the salt can absorb excess moisture, making the particulate detergent additive stronger
and more free-flowing. A neutral or alkaline salt has a pH in solution of seven or
greater. This salt can be either organic or inorganic. The water-soluble, neutral
or alkaline salt will be employed in the particulate detergent additive in an amount
from about 5% to about 75% by weight, preferably from about 5% to about 40% by weight,
and more preferably from about 10% to about 30% by weight of the particulate detergent
additive.
[0037] In another embodiment, the dispersion inhibitor/ static control agent intimate mixture
is admixed with the water-soluble neutral or alkaline salts described. herein and
this mixture is sprayed with water. The resulting product, which is free of conventional
agglomerating agents (such as dextrin glues), is a very effective static control product,
providing performance, cost and physical property benefits over similar agglomerates
which utilize conventional agglomerating agents. This embodiment is described in detail
in concurrently filed U.S. Patent Application Serial No. 961,447, Draper, incorporated-
herein by reference.
[0038] Examples of such water-soluble neutral or alkaline salts include alkali metal chlorides
such as sodium chloride and potassium chloride, alkali metal fluorides such as sodium
fluoride and potassium fluoride, alkali metal carbonates such as sodium carbonates,
alkali metal silicates, and mixtures thereof. Any conventional water-soluble, neutral
or alkaline inorganic salts such as the alkali metal sulfates, notably sodium sulfate,
can be employed in the present invention.
[0039] Water-soluble, neutral or alkaline salts also include the variety commonly known
as detergency builder salts, especially alkaline, polyvalent anionic builder salts.
Suitable detergency builder salts include polyvalent inorganic or organic salts or
mixtures thereof. Suitable water-soluble, preferred inorganic alkaline detergency
builder salts include alkali metal carbonates, borates, phosphates, polyphosphates,
bicarbonates, silicates, and sulfates. Specific examples of such salts include the
sodium and potassium tetraborates, perborates, bicarbonates, carbonates, tripolyphosphates,
pyrophosphates, orthophosphates and hexametaphosphates.
[0040] Examples of suitable organic alkaline detergency builder salts are: water-soluble
aminopolyacetates, e.g., sodium and potassium ethylenediaminetetraacetates, nitrilotriacetates
and N-(2-hydroxyethyl)nitrilodiacetates; water-soluble salts of phytic acid, e.g.,
sodium and potassium phytates; water-soluble polyphosphonates, including sodium, potassium
and lithium salts of ethane-l-hydroxy-l
rl-diphosphonic acid; sodium, potassium and lithium salts of methylene diphosphonic
acid and comparable examples.
[0041] Additional organic builder salts are disclosed in U.S. Patent 4,083,813, Wise, et
al, issued April 11, 1978, U.S. Patent 3,308,067, Diehl, issued March 7, 1967, and
U.S. Patent 2,264,103, Tucker, issued November 25, 1941. The disclosures of the above
patents are incorporated herein by reference. The Tucker patent particularly discloses
polycarboxylate and citrate salts, notably sodium citrate which may be used in the
present invention as a water-soluble, alkaline salt. Further detergency builder salts
are disclosed in the Baskerville et al patent.
Optional Clay Ingredient
[0042] The particulate detergent additive may optionally contain smectite clay as an ingredient.
These smectite clays may be admixed with the particulate detergent additive of this
invention at levels from about 5% to about 70% by weight, preferably from about 20%
to about 60% by weight,.and most preferably from about 25% to about 50% by weight
of the resulting admixture, to form compositions which provide laundered fabrics with
outstanding fabric softening and static control benefits. The clays used herein are
"impalpable", i.e., have a particle size which cannot be perceived tactilely. Impalpable
clays have particle sizes below about 50 microns; the clays used herein have a particle
size.range of from 5 microns to about 50 microns.
[0043] The clay minerals can be described as expandable, three-layer clays, i.e., aluminosilicates
and magnesium silicates, having an ion exchange capacity of at least 50 meq/100 g.
of clay and preferably at least 60 meq/100 g. of clay. The term "expandable" as used
to described clays relates to the ability of the layered clay structure to be swollen,
or expanded, on contact with water. The three-layer expandable clays used herein are
those materials classified geologically as smectites.
[0044] There are two distinct classes of smectite clays that can be broadly differentiated
on the basis of the number of octahedral metal-oxygen`arrangements in the central
layer for a given number of silicon-oxygen atoms in the outer layers.
[0045] The clays employed in the compositions of the instant invention contain cationic
counterions such as protons, sodium ions, potassium ions, calcium ions, and lithium
ions. It is customary to distinguish between clays on the basis of one cation predominantly
or exclusively absorbed. For example, a sodium clay is one in which the absorbed cation
is predominantly sodium. Such absorbed cations can become involved in exchange reactions
with cations present in aqueous solutions. A typical exchange reaction involving a
smectite-type clay is expressed by the following equation: smectite clay (Na) + NH
4OH smectite clay (NH
4)
+ + NaOH. Since, in the foregoing equilibrium reaction, one equivalent weight of ammonium
ion replaces an equivalent weight of sodium, it is customary to measure cation exchange
capacity (sometimes termed "base exchange capacity") in terms of milliequi- valpnts
per 100 g. of clay (meq/100 g.). The cation exchange capacity of clays can be measured
in several ways, including by electrodialysis, by exchange with ammonium ion followed
by titration or by a methylene blue procedure, all as fully set forth in Grimshaw,
"The Chemistry and Physics of Clays", pp. 264-265, Interscience (1971), incorporated
herein by reference.
[0046] The cation exchange capacity of a clay mineral relates to such factors as the expandable
properties of the clay, the charge of the clay, which, in turn, is determined at least
in part by the lattice structure, and the like. The ion exchange capacity of clays
varies widely in the range from about 3 meq/100 g. of kaolinites to about 150 meq/100
g., and greater, for certain smectite clays. Illite clays, although having a three
layer structure, are of a nonexpanding lattice type and nave an ion exchange capacity
somewhere in the lower portion of the range, i.e, around 26 meq/100 g. for an average
illite clay. Attapulgites, another class of clay minerals, have a spicular (i.e. needle-like)
crystalline form with a low cation exchange capacity (25-30 meq/100g). Their structure
is composed of chains of silica tetrahedrons linked together by octahedral groups
of oxygens and hydroxyl containing Al and Mg atoms.
[0047] It has been determined that illite, attapulgite, and kaolinite clays, with their
relatively low ion exchange capacities, are not useful in the instant compositions.
Indeed, illite and kaolinite clays constitute a major component of clay soils which
are removed from fabric surfaces by means of the instant compositions. However, the
alkali metal montmorillonites, saponites, and hectorites, and certain alkaline earth
metal varieties of these minerals such as calcium montmorillonites have been found
to show useful fabric-softening benefits when incorporated in compositions in accordance
with the present invention. Specific examples of such fabric-softening smectite clay
minerals are: sodium montmorillonite-, sodium hectorite, sodium saponite, calcium
montmorillonite, and lithium hectorite. Accordingly, smectite clays useful herein
can be characterized as montmorillonite, hectorite, and saponite clay minerals having
an ion exchange capacity of at least about 50 meq/100 g., and preferably at least
60 meq/lOOg.
[0048] The above discussion of optional clay additives is intended to only be a brief cursory
review of the subject matter contained in the Baskerville et al patent and in
U.S. Patent 4,062,647, issued to Storm et al on December 13, 1977, incorporated herein
by reference.
[0049] The smectite clays are preferably admixed with the particulate detergent additive
after the additive has been aged for a time sufficient for the complexing reaction
to have been substantially completed.
Surfactant
[0050] The particulate detergent additive of the present invention can be further incorporated
in a detergent composition, by, for example, dry mix addition, with a surfactant selected
from the group consisting of anionic, nonionic, zwitterionic and ampholytic surfactants,
and mixtures thereof. From about 5% to about 85% by weight, preferably from about
5% to about 50% by weight, and most preferably from about 10% to about 25% by weight
of the final detergent composition can comprise the organic surfactant component.
Examples of organic surfactants useful herein have been described above as possible
anionic complexing components, and are further described in U.S.-Patent 3,579,454,
issued to E.J. Collier on May 18, 1971, incorporated herein by reference, from column
11, line 45 through column 13, line 64. As extensive discussion of surfactants is
contained in the Baskerville et al patent, from column 11, line 39 through column
13, line 52, already incorporated hereinabove by reference.
Other Optional Ingredients
[0051] Other ingredients which are conventionally used in detergent compositions can be
included in the detergent compositions of the present invention. These components
include detergency builders, such as those enumerated in the Baskerville patent from
column 13, line 54 through column 16, line 17, as well as color speckles, bleaching
agents and bleach activators, suds boosters or suds suppressors, anti-tarnish and
anti-corrosion agents, soil suspending agents, soil release agents, dyes, fillers,
optical brighteners, germicides, pH adjusting agents, alkalinity sources, hydrotropes,
enzymes, enzyme- stabilizing agents, perfumes, alkyl polyethoxylate nonionic surfactants,
and other optional detergent compounds.
[0052] The detergent compositions of the instant invention can contain a detergency builder
in an amount from about 5% to about 85% by weight, preferably from about 15% to about
60% by weight of the entire detergent composition.
Method of Preparation
[0053] Initially, a solution containing from about 1% to about 80% by weight, preferably
from about 5% to about 50% by weight of an anionic complexing component is prepared.
Preferably, the anionic complexing component is present in solution at a concentration
close to its saturation point. Overall, the anionic complexing component represents
from about 1% to about 90% by weight, preferably from about 10% to about 60% by weight,
of the particulate detergent additive. The anionic complexing component is selected
from the group consisting of anionic synthetic surfactants; soaps, non-surfactant
electrolytes selected from the group consisting of alkali metal phosphates, borates,
carbonates, silicates, sulfates, and citrates; and mixtures thereof. In a preferred
embodiment, water alone is the solvent of the complexing solution. The solution is
sprayed onto the quaternary ammonium compound, resulting in the at least partial complexing
of the quaternary ammonium compound with the anionic complexing component. The complex
formed should constitute at least 25% of the surfaces of the anti-static particles.
More preferably, the complex constitutes at least 50% of the surfaces, and most preferably
the complex constitutes substantially all the surfaces of the antistatic particles.
[0054] The reaction can also result in the complexation of substantially all of the quaternary
ammonium compound, although it is preferred that the complexing be limited to the
surfaces of the antistatic particles. The anionic complexing component can optionally
be admixed as a solid with the quaternary ammonium compound prior to being complexed,
preferably by being sprayed with a complexing medium. This complexing medium is preferably
water or, with further improvement, a solution of anionic complexing component in
water.
[0055] In a preferred embodiment of the present invention, the quaternary ammonium antistatic
compound is intimately mixed with an organic dispersion.inhibitor and formed into
particulates, or prills, according to methods more fully described in the Baskerville
et al patent. As another preferred embodiment, a water-soluble neutral or alkaline
salt, preferably-sodium tripolyphosphate, is admixed with the prills prior to the
spray-on of either water alone or an anionic complexing solution. Water-soluble neutral
or alkaline salts agglomerated with these prills are described in U.S. Patent 4,141,841,
McDanald, issued February 27, 1979, incorporated herein by reference. This procedure
can also result in the formation of stable agglomerates consisting of the anionic
complexing component and the prilled particles. The agglomerates are substantially
free of organic agglomerating agents, and preferably, water alone acts as the agglomerating
agent. These agglomerates are fully described in concurrently filed U.S. Patent Application
Serial No. 861,447, Draper, incorporated herein by reference.
[0056] Smectite clay is optionally admixed or agglomerated into the additive product to
provide an additional fabric-softening benefit.
[0057] The complexing medium can be sprayed onto the quaternary ammonium antistatic compound
particles, prills, agglomerates, and other complexing components, in a mixer, such
as the Schugi mixer (Flexomix 160, 250, 335 or 400), the O'Brien mixer, the Littleford
mixer, the Patterson-Kelly mixer, ribbon mixers, a fluidized bed, and/or virtually
any of the conventionally-known pan agglomerators. The optional smectite clays can
be admixed with the additive product in a conventional pan agglomerator. The resulting
particulate detergent additive composition is aged for approximately one hour, optionally
mixed with silica if increased flowability is desired, and admixed with conventional
detergent granules.
[0058] As used herein, all percentages, parts and ratios given are "by weight", unless otherwise
specified.
[0059] The following nonlimiting examples illustrate the additives and compositions of the
present invention. As discussed hereinafter in the examples, the words "comparable
results" and substantially similar results" are intended to indicate that static control
benefits can also be obtained at reduced antistatic agent levels.
EXAMPLE I
[0060] A particulate detergent additive composition is prepared as follows
[0061]

[0062] The dimethyl di-hydrogenated tallow ammonium chloride (DTDMAC) and tallow alcohol
were melted together to form a clear solution at 250°F. This molten solution was atomized
at 1600 psi into a chamber with ambient temperature air passing through the chamber.
The atomized droplets froze into solid particles in the size range of about 20 microns
to about 150 microns. The softening point of the DTDMAC/tallow alcohol mixture was
about 165°F. The DTDM
AC/tallow alcohol mixture had a solubility of substantially less than 10 ppm in 25
0C water. The prills in all the subsequent examples have essentially the same characteristics.
[0063] Sodium tripolyphosphate (STP) and the DTDMAC/tallow alcohol prills, in a 7:4 ratio
of prill:STP were fed into a Schugi mixer (Flexomix 160) where they were thoroughly
admixed. The sodium tripolyphosphate was a dry, anhydrous, powder with at least 90%
passing through a 100-mesh Tyler sieve. The 7:4 ratio prill:STP mixture was sprayed
with an anionic complexing solution comprising 0.7 parts sodium citrate, per 1 part
water.
[0064] The reaction of the anionic complexing components (the sodium citrate and the STP)
with the DTDMAC in the prills resulted in the formation of a complex which con
- stituted substantially all of the surfaces of the prills. This product was the particulate
detergent additive of this Example.
[0065] The particulate detergent additive product was discharged from the Schugi Flexomix
160 mixer onto a plan agglomerator and there mixed with sodium montmorillonite clay
of good fabric softening performance and having an ion exchange capacity of about
63 meq/100 g. (available from Georgia Kaolin Co. USA under the trade name Brock),
which was also discharged onto the pan agglomerator. The resulting mix was aged for
approximately one hour, mixed with silica to increase flowability, and then admixed,
by dry mix addition, with a conventional detergent composition comprising surfactants,
builders and other optional detergent ingredients.
[0066] The particulate detergent additive product provided increased static control performance
and softening benefits relative to uncomplexed DTDMAC particles and to uncomplexed
DTDMAC/tallow alcohol prills, either alone, when merely admixed with anionic complexing
components or salts, or when agglomerated with anionic complexing components or salts,
using conventional organic agglomerating agents.
[0067] Comparable results are obtained when the insoluble complex constitutes at least 25%
of the surface of the DTDMAC particles or prills; and when the anionic complexing
component complexes substantially all of the DTDMAC in the particles or prills.
[0068] Comparable results are obtained when the anionic complexing components, or mixtures
thereof, are sprayed onto the DTDMAC particles or prills; when the complexing components
are contacted in a fludized bed reactor; and when the anionic complexing components,
or mixtures thereof, are admixed as solids with the DTDMAC particles or prills and
then sprayed with a complexing solution, which may comprise water and optionally other
anionic complexing components.
[0069] Substantially similar results are obtained when the sodium citrate and/or the STP
are replaced with other anionic complexing components, such as: sodium tetraborate,
potassium tetraborate, potassium tripolyphosphate, sodium pyrophosphate, potassium
pyrophosphate, sodium hexametaphosphate, potassium hexametaphosphate, sodium sulfate,
potassium sulfate, potassium citrate, anionic surfactants such as C
10-C
14 linear and branched alkylbenzene sulfonates and C
10-C
18 alkyl sulfates, and mixtures thereof.
[0070] Substantially similar results are obtained when sodium tripolyphosphate is replaced
with other water-soluble neutral or alkaline salts, such as: sodium tetraborate, potassium
tetraborate, potassium tripolyphosphate, sodium pyrophosphate, potassium pyrophosphate,
sodium hexametaphosphate, potassium hexametaphosphate, sodium sulfate, potassium sulfate,
sodium citrate, potassium citrate, and mixtures thereof.
[0071] Comparable results are obtained when the quaternary ammonium compound utilized is
ditallow dimethyl ammonium methylsulfate, ditallow dimethyl ammonium ethylsulfate,
1-methyl-1[(tallowamido)ethyl]-2-tallowimidazolinium methylsulfate, or mixtures thereof
in place of the ditallow dimethyl ammonium chloride on a part for part basis.
[0072] Substantially similar results are obtained when the organic dispersion inhibitor
is a mixture of C
10-C
22 alkyl sorbitan esters, the major component of which is one or more esters selected
from the group consisting of sorbitan trilaurate, sorbitan trimyristate, sorbitan
tripalmitate, sorbitan tristearate, sorbitan tetralaurate, sorbitan tetramyristate,
sorbitan tetrapalmitate, sorbitan tetrastearate, and mixtures thereof.
[0073] Comparable results are obtained when the organic dispersion inhibitor and/or the
water-soluble neutral or alkaline salt are deleted from the system.
[0074] Comparable results are obtained when the clay is deleted from the system, or when
other types of clay are substituted for sodium montmorillonite, such as sodium hectorite,
sodium saponite, calcium montmorillonite, lithium hectorite, ,and mixtures thereof.
[0075] The silica is an optional additive, and substantially similar results are achieved
without its inclusion.
[0076] Other types of mixers which are used in place of the Schugi Flexomix 160 are the
Schugi Flexomix 250, 335, and 400, the O'Brien mixer, the Littleford mixer, the Patterson-Kelly
mixer, ribbon mixers, and/or virtually any of the conventionally known pan agglomerators.
EXAMPLE II
EXAMPLE III
[0078] The particulate detergent additive of Example I is incorporated into a detergent
composition as follows:

[0079] The compositions of Examples II and III provide the static control advantages at
reduced antistatic agent levels, as described in Example I.
EXAMPLE IV
[0080] A particulate detergent additive composition was prepared as follows:
The 7:4 ratio prills:STP mixture of Example I was fed into a Schugi mixer and sprayed
with water. The water acted as an agglomerating agent and stable STP/prill agglomerates,
the particulate detergent additive of this Example, were formed. The agglomerates
were then discharged from the Schugi mixer onto a pan agglomerator and there admixed
with sodium montmorillonite clay. The resulting mix was aged for approximately one
hour, mixed with silica to increase flowability, and then admixed, by dry mix addition,
with a conventional detergent composition comprising surfactants, builders and other
optional ingredients.
[0081] The particulate detergent additive provided stable agglomerates and increased static
control performance and softening benefits-relative to STP/prill agglomerates formed
using conventional agglomerating agents, such as dextrin glues. Also, material costs
were reduced and extra processing and handling steps.were eliminated due to the elimination
of conventional agglomerating agents.
[0082] Substantially similar results are obtained when the STP/prill mixture is agglomerated
with solutions comprising water and being substantially free of organic agglomerating
agents.
[0083] Substantially similar results are obtained when sodium tripolyphosphate is replaced
with other water-soluble neutral or alkaline salts, such as: sodium tetraborate, potassium
tetraborate, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium
carbonate, potassium tripolyphosphate, sodium pyrophosphate, potassium pyrophosphate,
sodium hexametaphosphate, potassium hexametaphosphate, sodium sulfate, potassium sulfate,
sodium citrate, potassium citrate, and mixtures thereof.
[0084] Comparable results are obtained when the quaternary ammonium compound utilized is
ditallow dimethyl ammonium methylsulfate, ditallow dimethyl ammonium ethylsulfate,
1-methyl-l-[(tallowamido)ethyl]-2-tallowimidazolinium methyl-sulfate, or mixtures
thereof in place of the ditallow dimethyl ammonium chloride on a part for part basis.
[0085] Substantially similar results are obtained when the organic dispersion inhibitor
is a mixture of C
10-C
22 alkyl sorbitan esters, the major component of which is one or more esters selected
from the group consisting of sorbitan trilaurate, sorbitan trimyristate, sorbitan
tripalmitate, sorbitan tristearate, sorbitan tetralaurate, sorbitan tetramyristate,
sorbitan tetrapalmitate, sorbitan tetrastearate, and mixtures thereof.
[0086] Comparable results are obtained when the clay is deleted from the system, or when
other types of clay are substitute for sodium montmorillonite, such as sodium hectorite,
sodium saponite, calcium montmorillonite, lithium hectorite, and mixtures thereof.
[0087] The silica is an optional additive,'and substantially similar results are achieved
without its inclusion.
[0088] Other types of mixers which are used in place of the Schugi Flexomix 160 are the
Schugi Flexomix 250, 335, and 400, the O'Brien mixer, the Littleford mixer, the Patterson-Kelly
mixer, ribbon mixers, and/or virtually any of the conventionally known pan agglomerators.
EXAMPLE V
[0089] A particulate detergent additive composition was prepared as follows:
A 7:8 part ratio prills (DTDMAC/tallow alcohol) :STP mixture was agglomerated according
to the procedure of Example IV, and admixed with sodium montmorillonite clay.
[0090] The composition of the admix was as follows:

[0091] The above-described mix was admixed on a 31 part basis, by dry mix addition, with
the base detergent granule composition described in Example II. The detergent composition
demonstrated the benefits described in Example IV.
EXAMPLE VI
[0092] A 7:4 ratio prill:STP mixture was prepared according to the procedure of Example
I.. The mixture was sprayed with an anionic complexing solution in a Schugi mixer.
[0093] This procedure was repeated with other anionic complexing solutions being sprayed
onto other samples of 7:4 prill: STP mixtures. As a control composition, a 7:4 prill:STP
mixture was sprayed with a dextrin-water organic agglomerating agent solution. The
reaction of the anionic complexing components (the STP and the anionic component contained
in the solution) with the DTDMAC in the prills resulted in the formation of a relatively
insoluble complex which constituted at least 10% of the surfaces of the prills. Sodium
montmorillonite clay was admixed with the complexed prills and/or the complexed prill
agglomerates in a pan agglomerator. The resulting admix was incorporated into a conventional
detergent composition, by dry mix addition, with the base detergent granules of
Example II.
[0094] A series of fabrics were washed in these respective compositions, including the control
composition, at a wash water temperature of about 100
0F and at a water hardness of about 2 graints per gallon, and then dried under ordinary
machine drying conditions and at a dew point of about 40.5°F. These were full-scale
washer and dryer loads using conventional fabric bundles. The fabrics were then measured
for average volts per square yard using a Faraday cage apparatus and for number of
clings.
[0095] The results of these tests, under ordinary wash water and machine drying conditions,
demonstrated that the complexed prills and/or the complexed prill agglomerates formed
by spraying certain anionic complexing solutions onto the prill/STP mixture delivered
superior static control benefits to the fabrics at reduced antistatic.. agent levels
relative to the control composition formed by spraying a dextrin-in-water solution
onto the prill/ STP mixture.
[0097] The results were as follows:
