Molecular sieve abstract
The patent specification discloses a method of softening fabrics
by agitating them in an aqueous medium containing (a) a heavy duty
spray dried built synthetic detergent composition consisting of
10% sodium linear tridecyl benzene sulfonate, 2% of a nonionic detergent
which consists of a C.sub.14 -C.sub.15 fatty alcohol condensed with
an average of 11 ethylene oxide groups per molecule, 1% of a mixed
sodium coconut/tallow (20:80) fatty acid soap, 33% of pentasodium
tripolyphosphate, 7% of sodium silicate wherein the ratio of Na.sub.2
O to SiO.sub.2 is 1:2.35 0.5% sodium carboxymethyl cellulose, with
the balance of the detergent composition being optical brighteners,
about 38% sodium sulfate, and about 7% moisture; (b) a softening
composition consisting of about 20% of distearyl dimethyl ammonium
chloride, about 40% of Type A synthetic sodium molecular sieve zeolite
having a mean particle diameter of 5.9 to 6.4 microns and containing
about 21% water, and about 40% sodium perborate; wherein about 0.1%
to about 0.3% by weight of the aqueous medium consists of (a) and
(b), and the ratio of (a) to (b) is 2:1.
Molecular sieve claims
What is claimed is:
1. A method of softening fabrics which comprises agitating said
fabrics in an aqueous medium containing
(a) a heavy duty spray dried built synthetic detergent composition
consisting of 10% sodium linear tridecyl benzene sulfonate, 2% of
a nonionic detergent which consists of a C.sub.14 -C.sub.15 fatty
alcohol condensed with an average of 11 ethylene oxide groups per
molecule, 1% of a mixed sodium coconut/tallow (20:80) fatty acid
soap, 33% of pentasodium tripolyphosphate, 7% of sodium silicate
wherein the ratio of Na.sub.2 O to SiO.sub.2 is 1:2.35 0.5% sodium
carboxymethyl cellulose, with the balance of the detergent composition
being optical brighteners, about 38% sodium sulfate, and about 7%
moisture;
(b) a softening composition consisting of about 20% of distearyl
dimethyl ammonium chloride, about 40% of Type A synthetic sodium
molecular sieve zeolite having a mean particle diameter of 5.9 to
6.4 microns and containing about 21% water, and about 40% sodium
perborate;
wherein about 0.1% to about 0.3% by weight of the aqueous medium
consists of (a) and (b), and the ratio of (a) to (b) is 2:1.
Molecular sieve description
This invention relates to fabric softening compositions. More particularly,
it relates to such compositions which are compatible with synthetic
organic detergents, include a carrier material having detergent
building activity and which are useful as wash cycle fabric softeners.
The use of various chemical materials, especially water soluble
cationic compounds, as softeners for fabrics is well known. It is
also known to employ such materials for their softening effect during
laundering and particularly in the rinse cycle of the laundering
operation. Use of such a softener in the rinse cycle was formerly
required because the softeners heretofore employed, being mostly
cationic in nature, were not thought to be compatible with the principal
anionic types of detergents used in washing compositions. By far
the predominating type of detergent used in home and commercial
laundering has been that which contained organic anions, which products
are referred to as anionic detergents. Even traces of such anionic
materials often precipitate cationic softeners, thereby reducing
the effectiveness of the softeners. This manifestation of incompatibility
long prevented use of cationic softeners in the washing stage or
cycle of the laundering operation. In other words, it necessitated
use of the softener in the rinse cycle after rinses of the laundry
had removed anionic detergent.
To overcome the aforementioned disadvantage and to obtain a softening
agent useful in the wash cycle of the laundering process it has
been proposed in U.S. Pat. No. 4203852 to admix the softener with
a bleach and a water soluble carrier in granular or bead form. The
shaped carrier is a mixture of water soluble detergency builders,
such as sodium silicate and sodium carbonate, and usually also contains
organic detergent, e.g., a nonionic detergent. The preparation of
such carriers normally entails admixture of the foregoing ingredients
in an aqueous medium, followed by a dry operation, typically spray
drying. Such drying operation may involve volatilization of various
organic ingredients of the carriers, such as the nonionic detergent
and hence the manufacture of such prior art wash cycle softeners
could entail economic losses and atmospheric pollution if anti-pollution
devices for the spray dryer were not functioning adequately. Such
disadvantages are overcome and a detergent-compatible fabric softening
composition is provided by the present invention. The invention
is directed to a fabric softening composition, preferably suitable
for wash cycle use, comprising a water soluble organic (usually
cationic) fabric softening agent and, usually also acting as a carrier,
a particulate molecular sieve zeolite, preferably in substantially
gas-free univalent cation exchanging form, usually in a weight ratio
of about 1:1 to about 1:20 e.g., 1:2 to 1:6.
Preferably the ratio of cationic softener to molecular sieve zeolite
is about 1:1.5 to about 1:10. Typically the percentage of the softener
is 3 to 30% and that of the molecular sieve zeolite is 5 or 10 to
60%.
The fabric softening composition can be prepared by dry mixing
of the solid softener in particulate form with the molecular sieve
zeolite, thereby avoiding a dry operation which could produce atmospheric
pollution and loss of product. Other dry components of the product
may also be admixed and aqueous solutions or melts of some constituents
may be sprayed onto moving surfaces of other powdered components.
Spray drying or prilling operations may be used, if desired.
The present composition is compatible with anionic and nonionic
detergents and with mixtures thereof and hence can be applied to
fabrics using the wash cycle of conventional automatic laundering
processes, without objectionable loss of softening effectiveness.
If desired, a supplementary builder or filler and/or an organic
detergent, and/or a bleach can be incorporated in the present softening
composition to obtain a multifunctional product, effective not only
as a fabric softener but also as a detergent and stain remover.
In general the percentage of the organic detergent in the product
will be from 0 to 30%, and preferably will be about 5 to 25%. The
bleach content may usually be from 0 to 60% and is preferably about
10 to 60%. The supplementary builder content may be from 0 to 70%,
preferably 10 to 50%.
The molecular sieve zeolite component of the present composition
provides an excellent detergency building effect, being especially
effective against calcium hardness. However, if desired the softening
composition may contain additional builders such as water soluble
silicates or carbonates (or even phosphates), present at about a
5 or 10 to 70%, preferably 10 to 50% and most preferably 10 to 30%
level.
The present softening composition may also optionally include other
conventional additives, such as inert water soluble inorganic filler
salts and minor adjuvants having aesthetic or functional effects,
e.g., colorants, bactericides, organic anti-redeposition agents.
The filler may be 0 to 70%, preferably 30 to 70% and most preferably
30 to 55% of the product and the total of minor adjuvants usually
will not exceed 25%, with the proportion of each individual adjuvant
not exceeding about 10%, being typically in the range of about 0.01
to 5%.
The cationic fabric softening compounds useful in the composition
of the present invention are commercially known and comprise cationic
nitrogen-containing compounds, such as quaternary ammonium compounds
and amine salts containing one or two straight chain organic radicals
of at least 8 carbon atoms and preferably containing at least one
straight chain organic radical containing from 12 to 22 carbon atoms.
The preferred softening agents are quaternary ammonium softening
agents of the following formula: ##STR1## wherein R.sup.1 is a long
chain aliphatic radical having from 8 to 22 carbon atoms, R.sup.2
is a long chain aliphatic radical having from 8 to 22 carbon atoms
or a lower alkyl radical having from 1 to 6 carbon atoms or an aryl,
aryloxy, alkoxy or aralkyl radical of 6 to 28 carbon atoms, R.sup.3
and R.sup.4 are lower alkyl or hydroxyalkyl radicals having from
1 to 6 carbon atoms or hydroxypolyalkoxy alkyl radicals having from
4 to 20 carbon atoms, and X is a water soluble salt-forming anion,
such as a halide (chloride, bromide, iodide), sulfate, acetate,
hydroxide, or similar inorganic solubilizing monobasic or dibasic
radical. Additionally, the nitrogen may be a ring nitrogen, with
R.sup.2 and R.sup.3 being replaced by 4 to 5 carbon atoms in a ring.
Compounds of the formula wherein R.sup.1 R.sup.2 R.sup.3 and R.sup.4
each represent a straight chain aliphatic radical, such as alkyl,
yield especially good results. Examples of quaternary ammonium softening
agents within the formula which are suitable for use in the composition
of the present invention include the following: hydrogenated di-tallow
dimethyl ammonium chloride; ethoxylated distearyl dimethyl ammonium
chloride; dimethyl distearyl ammonium chloride; trimethyl stearyl
ammonium bromide; cetyl trimethyl ammonium chloride, di-coco dimethyl
ammonium chloride; cetyl pyridinium chloride; higher alkyl dimethyl
benzyl ammonium chloride; diisobutyl phenoxy ethoxy ethyl dimethyl
benzyl ammonium chloride; lauryl isoquinolinium bromide; distearyl
dimethyl ammonium bromidep; distearyl dimethyl ammonium methosulfate;
di-coco dimethyl ammonium chloride; dimethyl-diarachidyl behenyl
ammonium chloride; di(soya)dimethyl ammonium chloride; and stearyl
dimethyl benzyl ammonium chloride.
Also useful are softening agents of the formula: ##STR2## wherein
R.sup.5 is a long chain aliphatic radical having from 8 to 22 carbon
atoms, R.sup.6 is a lower alkyl radical having from 1 to 6 carbon
atoms, R.sup.7 is a higher alkyl amidoalkyl radical having from
8 to 22 carbon atoms or a hydroxyalkyl radical having from 2 to
6 carbon atoms. Examples thereof include 2-heptadecyl-1-methyl-1[(2-stearylamido)ethyl]imidazolinium
methyl sulfate and 2-heptadecyl-1 methyl-1-hydroxyethyl imidazolinium
chloride.
Examples of amines which may be utilized in the forms of their
water soluble salts in the composition of the present invention
include primary tallow amine, primary coco amine, primary hydrogenated
tallow amine, tallow 13-propylene diamine, oleyl 13-propylene
diamine, and coco 13-propylene diamine. The most useful water soluble
salts of the aforementioned amines are exemplified by the sulfate,
hydrogen sulfate and chloride. The term "coco", when utilized,
refers to fatty acid groups present in coconut oil fatty acids.
Such acids contain from about 8 to 18 carbon atoms per molecule,
with the C.sub.12-14 acids predominant.
The molecular sieves utilized in the invented compositions are
water insoluble crystalline aluminosilicate zeolites of natural
and synthetic origin which are characterized by having a network
of similarly or substantially uniformly sized pores in the range
of about 3 to 10 Angstroms, which size is uniquely determined by
the unit structure of the zeolite crystal. Of course, zeolite molecular
sieves containing two or more such networks of different size pores
may also be employed and noncrystalline zeolites have found use
too, at least as a part of the total zeolite molecular sieve content.
The molecular sieve zeolite should also be a univalent cation exchanging
zeolite. That is, it should be an aluminosilicate having in its
structure a univalent cation such as sodium, potassium, lithium
(in suitable cases) or other alkali metal, or ammonium. Preferably,
such univalent cation is an alkali metal cation and sodium and potassium
are most preferred.
Among the useful zeolites are those of the following crystal structure
types: A, X, Y, L, mordenite, chabazite and erionite. Mixtures of
these and equivalent molecular sieve zeolites can also be used.
These preferred crystalline structure types of molecular sieve
zeolites are well known in the art and are more particularly described
in the text Zeolite Molecular Sieves by Donald W. Breck, published
by John Wiley & Sons in 1974. Readily available commercial forms
of the preferred molecular sieve zeolites are described in Table
9.6 of the Breck text at pages 747-749 which table is hereby incorporated
by reference. Preferably the molecular sieve zeolite used in the
invention is a synthetic molecular sieve zeolite. Preferably also
the zeolite is one having a type A crystal structure, more particularly
described on page 133 of the aforementioned Breck reference, and
the pore size (nominal) thereof is about 4 Angstroms. The especially
preferred zeolite molecular sieves are described in U.S. Pat. No.
2882243 which refers to them as Zeolite A. However Types X and
Y are also very useful.
Molecular sieve zeolites can be prepared in either a dehydrated
or calcined form, which contains no more than about 0 to 3% of moisture,
usually 1 to 3%, or in a hydrated or water loaded form, which contains
additional adsorbed water in an amount up to about 36% of the zeolite,
depending on the type of zeolite used, e.g., 4 to 30%. Preferably
the water-containing hydrated form of the molecular sieve is employed
in this invention. If the anhydrous form is used it soon picks up
water and becomes hydrated. The manufacture of such zeolite molecular
sieve crystals is well known in the art. For example, in the preparation
of zeolite A, referred to above, the hydrated zeolite crystals that
are formed in the crystallization medium (such as a hydrous amorphous
sodium aluminosilicate gel) are used without the high temperature
dehydration (calcining to about 1 to 3% water content) that is normally
practiced in preparing such crystals for use as catalysts, e.g,
cracking catalysts. The preferred form of zeolite is either completely
hydrated or partially hydrated form can be recovered by filtering
off the crystals from the crystallization medium and drying them
in air at ambient temperature so that their water content is in
the range of about 20-28.5%, preferably about 20 to 22%.
The crystalline zeolites used in the invented compositions may
be substantially free of adsorbed gases, such as carbon dioxide,
which may produce foaming on contact with water. Of course, when
foaming is desired such gas-containing sieves are not usually objectionable
and may be preferred. Preferably the molecular sieve should be in
finely divided condition, such as crystals having mean particle
diameters in the range of about 0.5 to about 12 to 13 microns, preferably
5 to 9 microns.
The water soluble organic detergent which may be incorporated in
the present composition is advantageously an anionic or nonionic
detergent, with anionic detergents sometimes being preferred because
of their normally stronger detersive effects. However, the nonionics
are usually more compatible with the softening agents. The aforementioned
categories of organic detergents are described and exemplified in
McCutcheon's Detergents and Emulsifiers 1969 Annual (wherein such
compounds are listed by chemical formulae and trade names) and in
Surface Active Agents and Detergents, Vol. II, by Schwartz, Perry
and Berch (Interscience Publishers, 1958).
Suitable anionic detergents include higher (10 to 20 carbon atom)
alkyl benzene sulfonate salts wherein the alkyl group preferably
contains 10 to 16 carbon atoms. The alkyl group especially preferred
is a linear alkyl radical of about 11 to 13 or 11 to 14 carbon atoms.
Desirably, the alkyl benzene sulfonate has a higher content of 3-(or
higher)phenyl isomers and a corresponding low content (well below
50%) of 2-(or lower)phenyl isomers; in other terminology the benzene
ring is preferably attached in large part at the 3 or higher (e.g.,
4 5 6 or 7) position of the alkyl group and the content of isomers
in which the benzene ring is attached at the 2 or 1 position is
correspondingly low. One suitable type of such detergent is described
in U.S. Pat. No. 3320174.
Also useful anionic detergents are olefin sulfonate salts. Generally
they contain long chain alkenyl sulfonates or long chain hydroxyalkane
sulfonates (with the OH being on a carbon atom which is not directly
attached to the carbon atom bearing the --SO.sub.3 group). More
usually, the olefin sulfonate detergent comprises a mixture of these
two types of compounds in varying amounts, often together with long
chain disulfonates or sulfate-sulfonates. Such olefin sulfonates
are described in many patents, such as U.S. Pat. Nos. 2061618;
3409637; 3332880; 3420875; 3428654; 3506580; and British
Pat. No. 1139158 and in the article by Baumann et al. in Fette-Seifen-Anstrichmittel
72 No. 4 pp. 247-253 (1970). All the above-mentioned disclosures
are incorporated herein by reference. The olefin sulfonates are
usually of 12 to 18 carbon atoms per molecule.
Another useful class of water soluble organic anionic detergents
is that of the higher (10 to 20 carbon atoms), paraffin sulfonates.
These may be the primary paraffin sulfonates, made by reacting long
chain alpha olefins and bisulfites, e.g., sodium bisulfite, or paraffin
sulfonates having the sulfonate groups distributed along the paraffin
chain, such as the products made by reacting a long chain paraffin
with sulfur dioxide and oxygen under ultraviolet light followed
by neutralization with NaOH or other suitable base, as in U.S. Pat.
Nos. 2503280; 2507088; 3260741; and 3372188 and German Pat.
No. 735096. The hydrocarbon substituent of the paraffin sulfonate
preferably contains 13 to 20 carbon atoms. The paraffin sulfonate
will normally be a monosulfonate but, if desired, may be a di-,
tri- or higher sulfonate. Typically, a paraffin disulfonate is used
in admixture with the corresponding monosulfonate, for example as
a mixture of mono- and di-sulfonates containing up to about 30%
of the disulfonate.
The hydrocarbon substituent of the paraffin sulfonate will usually
be linear but branched chain paraffin sulfonates can be employed.
The paraffin sulfonate used may be terminally sulfonated or the
sulfonate substituent may be joined to the 2-carbon or other carbon
atom of the paraffin chain. Similarly, any di- or higher sulfonate
employed may have the sulfonate groups distributed over different
carbons of the hydrocarbon chain.
Other anionic detergents are water soluble salts of, for instance,
such high fatty carboxylic acids as lauric, myristic, stearic, oleic,
isostearic, palmitic, undecylenic, tridecylenic, pentadecylenic,
2-lower alkyl higher alkanoic (such as 2-methyl tridecanoic, 2-methyl
pentadecanoic or 2-methyl heptadecanoic) or other saturated or unsaturated
fatty acids of 10 to 20 carbon atoms or mixtures thereof. Soaps
of dicarboxylic acids may also be used, such as the soaps of dimerized
linoleic acid, and the soaps of the other higher molecular weight
acids such as resin or tall oil acids, e.g., abietic acid. A specific
suitable soap is the sodium soap of a mixture of tallow fatty acids
and coconut oil fatty acids, preferably in 85:15 ratio.
Other anionic detergents useful in the practice of this invention
are sulfates of higher alcohols, such as sodium lauryl sulfate,
sodium tallow alcohol sulfate and other sulfated oils or sulfates
of mono- or diglycerides of higher fatty acids, e.g., stearic monoglyceride
monosulfate; higher alkyl poly-(lower alkenoxy)ether sulfates, [the
sulfates of the condensation products of a lower (2 to 4 carbon
atoms) alkylene oxide, e.g., ethylene oxide, and a higher aliphatic
alcohol, e.g., lauryl alcohol], wherein the molar proportion of
alkylene oxide to alcohol is from about 1:1 to 5:1; lauryl or other
higher alkyl glyceryl ether sulfonates; and aromatic poly-(lower
alkenoxy)ether sulfates, such as the sulfates of the condensation
products of ethylene oxide and nonyl phenol (usually having 1 to
20 oxyethylene groups per molecule, preferably 2-12). The ether
sulfate may also be one having a lower alkoxy (of 1 to 4 carbon
atoms, e.g., methoxy) substituent on a carbon close to that carrying
the sulfate group, such as a monomethyl ether monosulfate of a long
chain vicinal glycol, e.g., a mixture of vicinal alkanediols of
16 or 17 to 18 or 20 carbon atoms in a straight chain.
Additional useful water soluble anionic detergents include the
higher acyl sarcosinates, e.g., sodium lauroyl sarcosinate; the
acyl esters, e.g., oleic ester, of isethionates; and acyl N-methyl
taurides, e.g., potassium N-methyl lauroyl- or oleyl tauride. Another
type of anionic detergent is a higher alkyl phenol sulfonate, for
example, a higher alkyl phenol disulfonate, such as one having an
alkyl group having some 12 to 25 carbon atoms, preferably a linear
alkyl of about 16 to 22 carbon atoms, which may be made by sulfonating
the corresponding alkyl phenol to produce a product containing in
excess of 1.6 preferably above 1.8 e.g., 1.8 to 1.9 or 1.95 SO.sub.3
H groups per alkyl phenol molecule. The disulfonate may be one whose
phenolic hydroxyl group is blocked, as by etherification or esterification;
thus the H of the phenolic OH may be replaced by an alkyl, e.g.,
ethyl, or hydroxyalkoxyalkyl, e.g., --(CH.sub.2 CH.sub.2 O).sub.x
H group, in which x is one or more, such as 3 6 or 10; and the
resulting alcoholic OH may be esterified to form a sulfate, e.g.,
--SO.sub.3 Na.
While the aforementioned structural types of organic carboxylates,
sulfates, and sulfonates are generally preferred types of anionic
detergents, the corresponding organic phosphates and phosphonates
are also useful as anionic surfactants. The sulfates and sulfonates
are preferred.
Generally, the water soluble anionic organic detergents are alkali
metal salts, such as potassium, lithium, and especially sodium salts,
although ammonium salts and substituted ammonium salts derived from
lower (2 to 4 carbon atoms) alkanolamines, e.g., methylamine, ethylamine,
sec-butyl amine, dimethylamine, tripropylamine and triisopropylamine,
are also useful.
The nonionic surfactants having the most desirable properties for
use in the softener compositions are usually inherently unctuous
pasty or tacky solids at room temperature, such as those having
melting points below about 40.degree. C. and having significant
volatility under commercial spray drying conditions. They may be
liquids which can be "solidified" into flowable particles
by spraying onto particulate solids, such as the zeolites Typical
nonionic detergents are poly(lower alkenoxy) derivatives that are
usually prepared by the condensation of a lower (2 to 4 carbon atom)
alkylene oxide, e.g., ethylene oxide, propylene oxide, with compounds
having a hydrophobic hydrocarbon chain and containing one or more
active hydrogen atoms, such as higher alkyl phenols, higher fatty
alcohols, higher fatty acids, higher fatty mercaptans, higher fatty
amides and polyols, e.g., fatty alcohols having a 8 to 20 typically
10 to 18 carbon atom alkyl chain and alkoxylated with an average
of about 3 to 20 typically 5 to 15 alkylene oxide units. Commercially
available nonionic surfactants falling into this category are Neodol
45-11 which is an ethoxylation product (having an average of about
11 ethylene oxide units per molecule) of a 14 to 15 carbon chain
fatty alcohol (Shell Chemical Company); Neodol 25-7 a 12 to 15
carbon chain fatty alcohol ethoxylated with an average of about
7 ethylene oxide units; Alfonic 1618-65 which is a 16 to 18 carbon
atom alkanol ethoxylated with an average of 10 to 11 ethylene oxide
units (Continental Oil Company); and Pluronic B-26 a 12 to 13 carbon
atom alcohol etherified with ethylene oxide and propylene oxide
(BASF Chemical Company).
Preferably, the detergent incorporated in the present softening
composition is an anionic detergent, especially an organic sulfonate
salt detergent, for best detergency. An especially good result is
generally obtained using as the detergent an alkali metal salt of
a linear higher alkyl benzene sulfonate having 10 to 16 carbon atoms
in the alkyl groups. However, the polyethoxylated higher fatty alcohols
are also excellent and may be used in place of or together with
the described anionic compounds.
Another important optional ingredient of the instant softening
composition is a bleach. The bleach may be an organic bleaching
agent such as N-bromo- and N-chloro-compounds, for example di- and
tri-chloro-(or bromo)cyanuric acids and water soluble salts thereof.
Preferably however, the bleach is inorganic and is most preferably
an inorganic peroxygen compound, such as a perborate, percarbonate,
perphosphate, persilicate, persulfate, hydrogen peroxide, alkali
metal peroxide or similar compound. Desirably those of the foregoing
bleaching agents which are salts are charged in the form of a water
soluble salt, preferably an alkali metal salt and especially a sodium
salt. Good results are obtained using sodium perborate or sodium
percarbonate as the bleach.
The present fabric softening composition may also contain an inert
water soluble inorganic salt as a filler. Typical examples of such
filler salts include alkali metal halides, such as sodium chloride
or alkali metal sulfates, such as sodium sulfate. Sodium sulfate,
particularly anhydrous sodium sulfate, is preferred. The softening
composition may also contain a small amount of moisture in addition
to that which may be adsorbed within the zeolite molecular sieve.
Generally, such moisture does not exceed 10% of the composition
and typically is only about 0.1 to 4 or 5%.
The water insoluble molecular sieve zeolite of the present fabric
softening compositions has an excellent building effect on organic
detergents (such as sodium linear higher alkyl benzene sulfonates)
which are charged to the washing machine for use in the wash cycle
and also builds such detergents which may be incorporated in the
softening compositions. However, if desired, water soluble builders
may be added to the softening composition to supplement the building
action of the molecular sieve zeolite. The supplementing builder
salts may be either organic or inorganic salts. Representative organic
builder salts include the water soluble salts of nitrilotriacetic
acid, citric acid, 2-hydroxyethylene, iminodicarboxylic acid, boroglucoheptanoic
acid, and polycarboxylic acids, e.g., polymaleates of low molecular
weight (generally below 1000 e.g., 400 600 or 800). Representative
inorganic builder salts include borax, alkali metal silicates, e.g.,
sodium silicates, having an Na.sub.2 O:SiO.sub.2 ratio in the range
of 1:1.5 to 1:3.2 and preferably 1:2 to 1:2.5 alkali metal polyphosphates,
such as pentasodium tripolyphosphate and tetrasodium pyrophosphate
(although these are often omitted for ecological reasons) and alkali
metal carbonates, such as sodium carbonate.
The supplementary builder is preferably an inorganic salt. An especially
desirable water soluble inorganic builder salt is sodium silicate,
which is particularly effective in sequestering magnesium cation
and thus is useful in overcoming water hardness not counteracted
by the molecular sieve, which is most effective against calcium.
Sodium silicate of an Na.sub.2 O:SiO.sub.2 molar ratio of about
1:2.35 yields excellent building results in the present softener
compositions.
The minor adjuvants which are optionally incorporated into the
present softening compositions to provide particular aesthetic and
functional effects include colorants, such as water insoluble inorganic
pigments, e.g., Ultramarine Blue, water insoluble organic pigments,
e.g., Indanthrene Blue R. S. and water soluble organic dyes, e.g.,
Color Index Direct Blue 1. The adjuvant colorant may also be one
of the fluorescent dyes known in the art as optical brighteners.
Such brighteners may be coumarins, triazolyl stilbenes, stilbene
cyanurics, acylamino stilbenes or miscellaneous types such as shown
in U.S. Pat. Nos. 2911514 and 3031460. The proportion of brightener
is usually quite small, e.g., in the range of about 1/20% to 1%,
preferably 1/10% to 1/2%. One suitable combination of brighteners
includes a naphthotriazole stilbene sulfonate brightener, sodium
2-sulfo-4-(2-naphtho-12-triazolyl)stilbene, another stilbene brightener,
bis(anilino diethanolamino triazinyl)stilbene disulfonic acid, another
stilbene brightener, sodium bis(anilino morpholino triazinyl)stilbene
disulfonate, and an oxazole brightener, having a 1-phenyl 2-benzoxazole
ethylene structure, 2-styryl naphtha[12d]oxazole, in relative proportions
of about 1:1:3:1.2.
Among the minor adjuvants may also be an organic anti-redeposition
agent, such as the alkali metal salts of carboxymethyl cellulose,
e.g., sodium carboxymethyl cellulose, polyvinyl alcohol, hydoxymethyl
ethyl cellulose, polyvinyl pyrrolidone, polyacrylamide, hydroxypropyl
ethyl cellulose or mixtures thereof. Preferably the anti-redeposition
agent added is sodium carboxymethyl cellulose.
Other important minor adjuvants which may be incorporated in the
softening compositions and softening-detergent compositions of the
invention include perfumes; fungicides or preservatives such as
polyhalosalicylanilides, e.g., tetrachlorosalicylanilide; sanitizers,
e.g., trichlorocarbanilide; foam destroyers, such as silicones;
enzymes, e.g., the subtilisin protease sold as Alcalase; and flow
improving agents such as the clay product commercially sold to the
detergent industry under the trade name of Satintone.
The softening composition of the invention will generally be made
and used as a powder. However, if desired, the particulate composition
of the invention can be compressed in a conventional manner to obtain
a tablet. Alternatively, the present invention can be converted
to a fluid paste by addition of up to about an equal weight of water
and subsequent thorough agitation of the resultant mixture. Addition
of more water converts it to a liquid but the insoluble molecular
sieve may settle out, requiring shaking before use.
The invented softening composition not only softens fabrics but
also reduces or eliminates static cling of the fabrics. The molecular
sieve zeolite acts as a carrier for the softening composition and
is a highly effective detergency builder; in other words it boosts
the cleaning effect of detergent compositions in which it is incorporated
or with which it is used. The molecular sieve zeolite carrier is
highly efficient in sequestering calcium ion when the present composition
is used in wash water of high calcium hardness. Accordingly at a
conventional 0.01 to 0.1% concentration of softener composition
(on a softening agent+molecular sieve basis) or a 0.1 to 0.3% concentration
of the softener-detergent, the invented compositions significantly
promote detersive action, even at calcium ion concentrations of
50 to 200 p.p.m. as CaCO.sub.3 or higher. Thus, additions of the
molecular sieve and softener to wash cycles in which separate detergent
composition is present results in noticeable increases in detergency
and building action.
The fabric softener-molecular sieve zeolite compositions may also
include a bleach and/or an organic detergent, and thereby become
highly effective multi-functional laundry treatment products capable
not only of imparting softening and anti-cling characteristics to
laundry but also of cleaning and bleaching out stains and spots.
The present softening compositions, optionally containing detergent
and/or bleach have found their greatest utility in the multi-functional
treatment of cotton fabrics, fabrics made of other cellulosic fabrics,
e.g., rayon, or other textile fibers, e.g., nylon, silk, wool, polyethylene
terephthalate, cellulose acetate, acrylonitrile polymers or copolymers
or blends of any two or more of these fibers, e.g., cotton-polyester
blends. The present detergent-containing compositions are especially
effective in removing clay and carbon soils, skin soil, natural
and artificial sebum soils, particulate soils, etc.
The softening compositions of the invention may be applied to laundry
in an aqueous bath either during the wash cycle of laundering or
as a separate and distinct softening treatment. Since the present
fabric softener compositions are compatible with anionic and nonionic
detergents they are preferably added to the washing cycle in the
laundering process. Normally about 25 to 100 g. preferably about
60 g. of the softening composition, corresponding to about 1 to
40 g. of softening agent, preferably 3 to 30 g., e.g., 10 g., are
added to an automatic washing machine or similar washing apparatus
containing 17 gallons (35 liters) of water and an average load of
laundry (about 5 to 10 pounds) for washing at a temperature of 20.degree.
to 70.degree. C., e.g., about 50.degree. C., over 5 minutes to 45
minutes. However, lesser or greater amounts may be utilized to obtain
the desired degree of softness, whiteness, and anti-static properties
depending on the water temperature, the water hardness, (hardnesses
of 20 to 200 p.p.m. CaCO.sub.3 are common), the amounts of water
and laundry, etc.
It was surprising to discover that in use of the present softening
composition containing a water insoluble carrier and builder, and
nolecular sieve zeolite, only a slight, almost imperceptible amount
of the molecular sieve zeolite remained as residue on the treated,
rinsed laundry and even this usually disappears in normal machine
tumble drying. The molecular sieve zeolite acts as a carrier, flow
improving agent, builder, disperser, extender and possibly, stabilizer
for the softening composition components and is compatible with
them. Additionally, it is non-eutrophic, non-polluting, biologically
safe and effective. Furthermore it can hold water and hardness ions
and thus prevent undesirable tackiness in the product and inactivation
of the detergent. Finally, it lends itself to easy and non-polluting
manufacturing techniques which require little capital investment
and little energy consumption.
The following examples illustrate the invention but do not limit
it. Unless otherwise noted all parts, percentages and proportions
are by weight and all temperatures are in .degree.C.
EXAMPLE 1
The above ingredients are mixed together in the dry state. Fifty
grams of the resulting particulate fabric softening composition
are added during the wash cycle of an automatic washing machine
wherein two white terrycloth towels are being laundered at 50.degree.
C. in 35 liters of water of 100 p.p.m. calcium hardness, as CaCO.sub.3
with 100 g. of a conventional heavy duty spray dried built synthetic
detergent composition containing 10% sodium linear tridecyl benzene
sulfonate, 2% of nonionic detergent (a C.sub.14 -C.sub.15 fatty
alcohol condensed with an average of 11 ethylene oxide groups per
molecule), 1% of mixed sodium coconut/tallow (20:80) fatty acid
soap, 33% of pentasodium tripolyphosphate, 7% of sodium silicate
(Na.sub.2 O:SiO.sub.2 =1:2.35), 0.5% sodium carboxymethyl cellulose,
with the balance of the detergent composition being optical brighteners,
sodium sulfate (about 38%) and moisture (about 7%). After thorough
air drying of the washed and rinsed towels, they are rated for softness
on a numerical scale of 1 to 10 wherein 1 represents no softness
and 10 represents excellent softness. Both towels are rated 10
indicative of the exceptional softness imparted by the softening
composition and of the compatibility of the present softening composition
with the anionic and nonionic detergents used in the laundering
process. The towels are not only clean but also are desirably white
in appearance. Careful inspection of the towels reveals only a slight,
almost unnoticeable deposit of the particulate molecular sieve zeolite
and this is lost when they are machine dried.
The foregoing laundering process is repeated, using the same conditions
and concentrations except that the above softening composition is
applied to the towels after the wash cycle, following complete removal
by rinsing of the detergent. The rinsed and dried towels have substantially
the same excellent degree of softness, whiteness and little or no
residue. In the above described softening bleach composition similar
results are obtained when the perborate bleach is replaced by sodium
percarbonate. Also, replacement of the molecular sieve with a type
X, Y or L sieve or with mixtures of these or mixtures with a type
A sieve gives the same type of results, as does replacement of the
anionic detergent with an olefin sulfonate or a paraffin sulfonate.
EXAMPLE 2
The above ingredients are mixed together in the dry state to obtain
a free flowing detergent-softener powder. Fifty and one hundred
grams of the resultant powder are used in separate experiments to
wash two terrycloth towels in an automatic washing machine at 50.degree.
C., employing 35 liters of tap water (of about 100 p.p.m. CaCO.sub.3
hardness). After rinsing and air drying the towels are rated for
softness, as in Example 1 and are both rated 10.sup.+, as being
of exceptional softness. The towels are not only exceptionally clean
but also contain only a slight deposit of molecular sieve zeolite
particles, which is removable by tumble drying.
In a control experiment two terrycloth towels are washed according
to the foregoing procedure using a softener-detergent composition
which is identical to that described above except that the molecular
sieve zeolite builder-carrier component is replaced by sodium tripolyphosphate.
The softness ratings of both rinsed and dried towels in the control
experiment are only 8 indicative of the superiority of the fabric
softening compositions containing molecular sieve zeolites.
In the above described fabric softening-detergent composition substantially
similar results are obtained if part of the anionic detergent, e.g.,
2%, based on the weight of the entire composition, is replaced by
a nonionic detergent, for example, a linear C.sub.14 -C.sub.15 fatty
alcohol condensed with an average of 11 ethylene oxide groups per
molecule. Also if desired, a portion, e.g., 15%, of the filler may
be replaced by a supplementary builder such as sodium silicate of
Na.sub.2 O:SiO.sub.2 ratio of 1:2.35. If desired, the composition
may also contain small proportions, e.g., 0.5% each, of such conventional
adjuvants as sodium carboxymethyl cellulose (an anti-redeposition
agent) and perfume. Such products have the same good performance
characteristics as were reported on the experimental softener composition.
EXAMPLE 3
In the foregoing two examples substantially similar excellent results
are obtained when the molecular sieve zeolite carrier is replaced
by a type A sodium molecular sieve zeolite having a mean particle
diameter of 8.3 microns (Linde Type 4A molecular sieve, Union Carbide
Corp.). Also, where components are changed in kind or proportion,
as described in the foregoing specification, excellent softening
and detergency-softening results and laundry washed is soft and
static-free. Bleaching effects of the per-compounds are improved
by the presence of an activator to promote decomposition of the
per-compound in the wash water or by raising the washing temperature
to in excess of 70.degree. C.
The invention has been described with respect to working examples
and illustrations thereof but is not to be limited to these because
it is evident that one of skill in the art with access to the present
specification will be able to employ substitutes and equivalents
without departing from the spirit or scope of the invention. |