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BACKGROUND OF THE INVENTION
(1) Field of Invention
This invention relates to non-aqueous liquid fabric treating composition
products. More particularly, this invention relates to unitary dispenser
packages for low- or no-phosphate, hydroxy polycarboxylic acid salt built
non-aqueous liquid laundry detergent compositions which are stable against
phase separation and gelation and are easily pourable and to the use of
these packaged compositions for cleaning soiled fabrics.
(2) Discussion of Prior Art
Liquid non-aqueous heavy duty laundry detergent compositions are well known
in the art. For instance, compositions of that type may comprise a liquid
nonionic surfactant in which are dispersed particles of a builder as
shown, for instance, in U.S. Pat. Nos. 4,316,812; 3,630,929; 4,254,466;
4,615,820; and 4,661,280.
Liquid detergents are often considered to be more convenient to employ than
dry powdered or particulate products and, therefore, have found
substantial favor with consumers. They may have one or more of the
following advantages: readily measurable; speedily dissolved in the wash
water; easily applied in concentrated solutions or dispersions to soiled
areas on garments to be laundered; non-dusting; occupy less storage space.
Additionally, the liquid detergents may have incorporated in their
formulations materials which could not withstand drying operations without
deterioration, which materials are often desirably employed in the
manufacture of particulate detergent products. Although they are possessed
of many advantages over unitary or particulate solid products, liquid
detergents often have certain inherent disadvantages, too, which have to
be overcome to produce acceptable commercial detergent products. Thus,
some such products separate out on storage and others separate out on
cooling and are not readily redispersed. In some cases the product
viscosity changes and it becomes either too thick to pour or so thin as to
appear watery. Some clear products become cloudy and others gel on
standing.
To some extent these problems, particularly as they may be perceived by the
consumer, may be partially or completely solved, by incorporating the
detergent composition in a unitary package. By "unitary package" is meant
a single use disposable package having therein an amount of fabric
treating composition appropriate for a single full or partial (e.g. 1/4 or
1/2) load of laundry. For instance, for a unitary package separation of
phases may not be so significant since the entire package and content is
added to the washing machine.
There have been many proposals in the patent literature for unitary
packages for fabric treating compositions, usually for powdery or
particulate products, but also for aqueous and non-aqueous liquid
formulations. Prepackaged detergent compositions provide several
advantages, such as eliminating the need to measure and dispense measured
quantities of bulk detergent from a large container, less dusting, less
handling of potentially irritating ingredients, such as high alkalinity,
bleach components, and so on.
Representative of the art relating to unitary packages for dispersing
powdery, liquid or paste fabric treating or other types of compositions in
aqueous media mention may be made of U.S. Pat. Nos. 3,186,869; 3,277,009;
3,322,674; 3,528,925; 3,892,905; 4,115,292; 4,348,293; 4,356,099;
4,416,791; 4,608,187; 4,610,799; 4,626,372 and Canadian Patent 1,112,534.
Clarke, et al., in U.S. Pat. No. 4,348,293, mentioned above, describe a
package for powdery detergent comprising an outer water-insoluble,
water-permeable bag and a water-soluble or dispersible protective inner
layer. The package may be in the form of a laminate or as separate sheets,
properly folded to encase the powdery detergent. The protective inner
layer being essentially non-porous, avoids dusting of the powder
composition during the bag filling operation and during use of the
package.
For liquid detergent formulations, e.g. suspensions of detergent builder
particles in liquid nonionic surfactant, although dusting may not be a
problem, nevertheless the liquid phase of the composition, especially for
liquid formulations of relatively low viscosity, e.g. below about 10,000
centipoise, may leak through the protective inner layer or through any
imperfectly formed seams or seals. The same is true, although to a lesser
extent, for more viscous liquids, pastes, gels and creams.
It has now been found that the double wall bag construction disclosed by
Clarke, et al. may be adapted to any of these pourable low viscosity, high
viscosity, paste, gel or cream non-aqueous liquid detergent compositions
by proper selection of the material of the water-soluble or dispersible
protective inner layer which will avoid leakage of the non-aqueous liquid
phase but which will still dissolve or disperse in cold, warm or hot wash
water within a reasonably short period of time to release their content
into the wash water.
Another potential problem of the Clarke, et al. bag construction is that
when the outer water-insoluble, water-permeable bag is sufficiently porous
to allow rapid penetration of the wash bath water into the interior of the
package to dissolve the inner water-soluble bag and release the detergent
composition, if the bag is stored under high humidity conditions, or
accidentally comes into contact with water, the inner water-soluble bag
may be prematurely dissolved or weakened to allow leakage of the liquid
contents. Therefore, in a preferred embodiment of this invention, there is
provided a third outermost removable layer of water-insoluble
water-impermeable material to protect the package from exposure to or
contact with moisture, including atmospheric moisture.
As stated above, by providing the liquid detergent compositions in unitary
packages, problem of phase separation, gelling and so on may not be
perceived by the consumer and, therefore, may not appear to require
special stabilizing systems or other precautions during manufacture.
Nevertheless, product stability is an important consideration for the
manufacturer since in many cases there may be substantial delays in time
between the bulk formulation of the product and the packaging thereof into
the unitary doses. Also, the bulk formulations may be made at one location
and packaged at a second remote location. In either case, it is important
to maintain the product as homogeneous as possible from the time the
composition is first formulated until it is filled into the individual
packages. It is also important that the physical characteristics of the
detergent compositions, such as viscosity, gel formation, agglomeration of
suspended solid particles, are not substantially changed or caused to
occur over time, such as during storage, shipping or in the course of the
filling operation. Any such changes in physical characteristics could
seriously adversely impact on the filling operation and filling apparatus
and could lead to over or underfilling of the packages, clogging of the
filling nozzles or similar problems.
Therefore, in accordance with a preferred embodiment of the invention the
non-aqueous heavy duty built laundry detergent composition is formulated
with appropriate rheology modifiers, including one or more of viscosity
modifiers, antigelling agents and physical stabilizers, in addition to the
essential liquid detergent component and suspended solid particles
comprising detergent builder salt, particularly hydroxy polycarboxylic
acid salt, and other optional functional or aesthetic laundry detergent
additives.
The washing power of synthetic nonionic surfactant detergents in laundry
detergent compositions can be increased by the addition of builders.
Sodium tripolyphosphate is one of the preferred builders. However, the use
of polyphosphate builders in detergents does involve several disadvantages
such as, for example, the tendency of the polyphosphates to hydrolyse into
pyro- and orthophosphates which represent less valuable builders.
In addition, the polyphosphate content of laundry detergents has been
blamed for the undesirably high phosphate content of surface water. An
increased phosphate content in surface water has been found to contribute
towards greater algae growth with the result that the biological
equilibrium of the water can be adversely altered.
Recently enacted government legislation has been directed to reducing the
amount of polyphosphates present in laundry detergents and in some
jurisdictions in which polyphosphates have been a problem to require that
the laundry detergents not contain any polyphosphate builders.
Therefore, still further improvements are desired in the stability and
performance of built non-aqueous liquid fabric treating compositions and
the means for dispensing same in a manner most convenient for consumers.
OBJECTS AND SUMMARY OF INVENTION
Accordingly, it is an object of the invention to provide unitary packages
for built non-aqueous liquid fabric treating compositions which are
suspensions of insoluble fabric treating particles in a non-aqueous liquid
and which are storage stable and dispersible in cold, warm or hot water.
Another object of this invention is to provide unitary packages of no- or
low-polyphosphate highly built heavy duty non-aqueous liquid nonionic
surfactant laundry detergent compositions which resist settling of the
suspended solid particles or separation of the liquid phase.
It is also an object of this invention to provide unitary packages with
non-aqueous liquid detergent compositions which are freely flowing and
easily pourable, even at temperatures of 5.degree. C or lower, and which
are readily filled into a double wall sachet package having a
water-insoluble, water permeable outer layer and a water-soluble or
dispersible liquid impermeable protective inner layer.
Still another object of this invention is to provide a disposable single
use double wall sachet package for a non-aqueous liquid laundry detergent
composition which package is inexpensive in construction and which
includes a waterproof outermost layer to protect the package from
premature exposure to moisture or dirt.
These and other objects of this invention which will become more apparent
from the following detailed description and preferred embodiments are
provided by a detergent product which comprises a double wall sachet
including a water-soluble liquid impermeable inner layer surrounding a
non-aqueous liquid detergent composition and a water-insoluble,
water-permeable bag surrounding the inner layer, the liquid detergent
composition comprising a no- or low-phosphorus non-aqueous liquid laundry
detergent composition which includes a non-aqueous liquid composed of
nonionic liquid surfactant, fabric treating solid particles suspended in
the non-aqueous liquid, and an amount effective to reduce the product's
viscosity and lower its gelling temperature of an alkylene glycol
monoalkyl ether solvent, wherein at least 50% by weight of the fabric
treating solid particles are comprised of a salt of hydroxy polycarboxylic
acid as detergent builder.
Accordingly, in one aspect the present invention provides a detergent
product comprising a liquid heavy duty laundry composition composed of
hydroxy polycarboxylic acid detergent builder salt in a liquid nonionic
surfactant and an alkylene glycol alkyl ether solvent in an amount to make
the suspension pourable even at temperatures as low as 5.degree. C or
below, the liquid composition being packaged in a sachet comprising a
closed water-insoluble, water-permeable outer bag and an inner layer of a
water-soluble liquid impermeable material separating the liquid
composition from the outer bag.
According to another aspect, the invention provides a single use disposable
package for dispensing a non-aqueous built liquid laundry detergent
composition wherein the package comprises a multicomponent sachet
including an outer bag fabricated from water-insoluble, water-permeable
non-woven fabric, an inner bag fabricated from a film of water-soluble or
dispersible, liquid impermeable material which is heat-sealable at least
along the outer edges, and surrounding the outer bag, a removable envelope
of water-insoluble water-impermeable material to protect the water-soluble
inner bag from exposure to or contact with moisture and dirt prior to
adding the sachet, to an aqueous wash bath.
DETAILED DESCRIPTION OF INVENTION AND PREFERRED EMBODIMENTS
In accordance with the invention, a non-aqueous liquid laundry detergent,
preferably one that is readily pourable, is pre-packaged in premeasured
dosage forms for single use in discardable packets or sachets.
A multicomponent disposable sachet dispenser is used of the type generally
disclosed in U.S. Pat. No. 4,348,293 to Clarke, et al. the disclosure of
which as it relates to the bag construction, materials and fabrication, is
incorporated herein by reference thereto. Accordingly, only the preferred
embodiments and unique features of the multicomponent sachets to be used
in this invention need be described. The sachet dispenser includes an
outer pouch or bag of a water-permeable or porous water-insoluble film or
fabric and an inner pouch or bag of a water-soluble or dispersible, liquid
impermeable film. The inner bag is filled with the appropriate unit dosage
of the non-aqueous liquid detergent composition and is then sealed. The
outer bag is sealed around the inner bag which may be free floating
therein, i.e. not attached to the walls of the outer bag, or it may be
sealed to one or more edges or walls thereof by any suitable means, such
as adhesives, heat sealing, staples, sewing, etc. In use in the aqueous
wash bath the water from the bath permeates or flows through the outer bag
and contacts the inner bag which then dissolves upon exposure to the water
and exposes the detergent composition to the wash water inside the pouch
and allows the fabric treating detergent, detergent builder, and so on, to
permeate out of the outer bag to the aqueous wash bath. In this way, the
invention composition can be gradually introduced into the wash bath
during the wash cycle, preferably over the course of one or more minutes,
for example, within 1 to 5 minutes, such as about 2 to 3 minutes. Although
the non-water-soluble outer bag can be fabricated from a perforated
water-insoluble material, e.g. resin impregnated paper, wax paper,
viscose, polyolefin film, polyester film, etc. it is preferred to form the
outer bag from non-woven fabric using fibers of natural or synthetic
origins or mixtures thereof. Nonwoven polyester fabrics of density ranging
from about 10 to 40 grams per square meter, preferably 15 to 30 grams per
square meter, especially 18 to 24 grams per square meter have proven
effective in practice.
Another preferred material for the outer bag is highly porous spun-bonded
non-woven polypropylene. The fabric density may be the same as described
for the non-woven polyester fabrics.
Other suitable fiber materials include, for example, polyamides,
polyacrylics, polyolefins, such as polyethylene, polypropylene,
ethylene-propylene copolymers, etc., polyvinyl chloride, polyvinylidene
chlorine, rayon, cellulose and the like.
It has been found convenient for most product formulations to use from
about 50 to 150 grams of the detergent composition, preferably 60 to 120
grams, such as 70, 80, 90, 100 or 110 grams, per wash, this amount
conveniently fitting in a single sachet dispenser, measuring, for example,
from about 3 to 4 or more inches per side, such as 3.5 in. or 3.75 in. or
4 in. per side.
Polyvinyl alcohol having a degree of hydrolysis of at least 60%, preferably
80 to 100%, such as 85 to 98%, e.g. 88% is preferably used as the
water-soluble film or sheet for forming the water-soluble liquid
impermeable inner bag of the sachet. Other water-soluble films or sheets
can also be used. For example, mention may be made of polyethylene oxide,
methyl cellulose, gelatine, polysaccharides, polyacrylic acid and the
like.
In order to make the water-soluble film material impervious to the
non-aqueous liquid phase it is important that it be non-porous and such
non-porous films are readily commercially available. Furthermore, the film
material should have suitable thickness. Generally, depending on the
nature of the water-soluble film material thicknesses of at least about 4
mil (.0.004 inch), preferably at least 10 mil will be selected. On the
other hand the film should not be so thick as to require excessively long
periods for dissolution after placement in the wash bath. Therefore,
thickness up to about 100 mil, preferably up to about 50 mil will be
selected.
Another important factor for selection of suitable water-soluble
film-forming material to obtain the required impermeability to the
non-aqueous liquid phase while still having acceptable dissolution
properties is the molecular weight of the film. For instance, in the case
of polyvinyl alcohol films a molecular weight of about 40,000 provides
fast dissolution rates, even in cold water, but could be partially
permeable to the non-aqueous liquid phase. Polyvinyl alcohol films with
molecular weight of about 80,000 are non-permeable to the non-aqueous
liquid phase but require longer periods to dissolve in cold water, but
rapidly dissolve in warm water (about 30.degree. C or higher). Therefore,
for liquid detergent compositions to be acceptable for us with cold wash
water, polyvinyl alcohol films with molecular weights of from about 45,000
to about 75,000 are preferred although lower or higher molecular weights
may be acceptable. For use under warm water conditions higher molecular
weights, e.g. from about 60,00 to 100,000 offer acceptable dissolution
rates and good liquid impermeability.
Appropriate molecular weight ranges can be easily determined for other
water-soluble film forming materials and for any particular non-aqueous
liquid detergent composition by routine experimentation.
As an alternative to the use of water soluble films for the inner
protective bag layer it is possible to use perforated films of
water-insoluble materials with the perforations filled or "blocked" with a
water-soluble substance, such as any of the water-soluble substances
mentioned above. The holes, or perforations, can cover, for example, from
about 20 to 80% of the total area of one or both major sides of the inner
bag and may conveniently range from about 1/8 square inch to about 1/2
square inch in area. The perforations can be in any desired geometrical
configuration and array, e.g. circular perforations in a square pattern,
star-shaped perforations in a circular pattern, etc.
The use of a double wall sachet wherein the outer wall is formed of a
sealed water-insoluble water-permeable material has several advantages.
The water-insoluble outer bag can protect the water-soluble inner bag from
exposure to moisture, e.g. humidity, during storage, but being
water-permeable will allow exposure of the water-soluble film and liquid
detergent product to the aqueous wash bath so that the detergent and
fabric treating ingredients can be dispersed to the fabrics during the
wash cycle. Furthermore, because the outer bag of the sachet is and
remains sealed during the washing, rinsing, and spin-dry operations of the
washing machine, any residue of the water-soluble inner bag will be
substantially retained within the sachet rather than being deposited on
the fabric being laundered. For instance, portions of the partially
hydrolyzed polyvinyl acetate may be water-insoluble and form clumps upon
dissolution of the water-soluble portions. These clumps will be
substantially retained within the water-insoluble outer bag. Also, it may
in some case be advantageous to render the inner bag partially
water-insoluble, for example, by a wax coating, to enhance storage
stability. This wax coating will also be retained within the permeable but
insoluble outer bag of the sachet.
However, it has been found that, in practice, effective and convenient
means for protecting the water-soluble inner bag and its liquid content
from premature exposure to moisture, whether water vapor in humid
environments, or accidental contact with water during storage, shipment or
during use and handling by the consumer, is simply to provide a removable
protective water-insoluble water-impermeable wrapper as the outermost
layer of the sachet.
Any water-insoluble water-impermeable (e.g. non-porous) film forming
material can be used for this purpose. For example, mention may be made of
polyolefin films, polyester films, polyvinyl chloride films,
polyvinylidene chloride and other polymer materials, water resistant
papers, wax papers, metal foil, e.g. aluminum foil, and the like. In this
context, the water-insoluble water-impermeable protective outermost
wrapper is to be distinguished from the "removable water-insoluble
protecting agent" as used in the aforementioned U.S. Pat. No. 4,348,293
which is applied as a coating to the water-insoluble water-permeable film
and which depends on being dispersed in the wash bath for removal.
Thus, the outermost wrapper may be formed in any convenient structure which
permits its easy removal by the consumer. For example, baggie-type (e.g.
PVDC) pouches may be used with the open end temporarily closed by a tie
string, or by a lock fit, or peelable adhesion. Alternatively, the heat
sealable plastic materials may be heat sealed along all open edges (e.g.
all four edges when two separate film sheets are used or along three edges
when a single film sheet is folded on itself) and provided with a
frangible score line, or notched at one edge o allow easy tearing.
Biaxially oriented polypropylene film is easily tearable and is highly
waterproof. When metal foil is used as the outermost protective wrapper it
too may be temporarily sealed by any convenient means, such as by
adhesive, or the metal foil may be simply securely folded upon itself
according to well known means.
By virtue of the outermost protective waterproof wrapper the detergent
product may be stored under high humidity conditions or may be otherwise
exposed to water without causing premature dissolution of the inner
water-soluble bag or leaking of the liquid detergent composition.
In addition to its protective function against exposure to moisture, the
outermost protective wrapper also protects the water-permeable outer bag
from contact with ambient dirt and dust which might adversely effect the
permeability of the product. Furthermore, especially for the non-woven
fabric types of outer bag material, dirt or dust particles may become
entrapped in the fibrous material and render the article unacceptable to
the end user.
While the outermost protective wrapper has been described as a separate,
independent cover, it is also possible to laminate the outermost wrapper
to the water-insoluble water-permeable outer bag using a peelable adhesive
or by heat sealing along one or more edges.
In any case, it is a simple task for the consumer to remove the outermost
protective wrapper before the detergent product is placed in the laundry
machine.
As described in Clarke, et al. U.S. Pat. No. 4,348,293 it is also possible
to provide suitable markings, e.g. printed advertisements, designs,
instructions for use, etc., on either or both of the outermost waterproof
protective wrapper or the outer water-permeable bag.
It is also within the scope of the invention to provide a coating on the
fibers of the outer water-insoluble, water-permeable non-woven fabric bag
of a fabric softening composition, such as a cationic quaternary ammonium
salt, perhaps with a water-insoluble wax, such that the softening agent
will not be activated (released) until the sachet is transferred, together
with the wash textile fabrics, to a clothes drier. Such "through the wash"
fabric softening materials are, per se, known in the art.
Similarly, the non-woven fabric may be impregnated with perfume or
fragrance to be transferred to the washed articles.
Also, the detergent products, in any of the foregoing embodiments, may be
formed in a conjoined manner, for example, in a strip, with severable
joints, to facilitate dosing of different numbers of bags as appropriate
for different washing conditions and laundry loads.
The liquid detergent composition of the detergent product will now be
described.
The liquid phase of the non-aqueous liquid detergent composition of this
invention is comprised of liquid nonionic synthetic organic detergent and
alkylene glycol monoalkyl ether, as a viscosity control and antigelling
agent. A portion of the liquid phase may be composed, however, of other
organic solvents which may enter the composition as solvent vehicles or as
carriers for one or more of the solid particulate ingredients, such as in
enzyme slurries, perfumes, and the like.
The nonionic synthetic organic detergents employed in the practice of the
invention may be any of a wide variety of such compounds, which are well
known and, for example, are described at length in the text Surface Active
Agents, Vol. II, by Schwartz, Perry and Berch, published in 1958 by
Interscience Publishers, and in McCutchen's Detergents and Emulsifiers,
1969 Annual, the relevant disclosures of which are hereby incorporated by
reference. Usually, the nonionic detergents are polylower alkoxylated
lipophiles wherein the desired hydrophile-lipophile balance is obtained
from addition of a hydrophilic polylower alkoxy group to a lipophilic
moiety. A preferred class of the nonionic detergent employed is the
polylower alkoxylated higher alkanol wherein the alkanol is of 10 to 22
carbon atoms and wherein the number of mols of lower alkylene oxide (of 2
or 3 carbon atoms) is from 3 to 20. Of such materials it is preferred to
employ those wherein the higher alkanol is a higher fatty alcohol of 10 to
11 or 12 to 15 carbon atoms and which contain from 5 to 18, preferably 6
to 14 lower alkoxy groups per mol. The lower alkoxy is often just ethoxy
but in some instances it may be preferably mixed with propoxy. Exemplary
of such ethoxylated alcohols are those wherein the alkanol is of 12 to 15
carbon atoms and which contain about 7 ethylene oxide groups per mol,
e.g., Neodol 25-7 and Neodol 23-6.5, which products are made by Shell
Chemical Company, Inc. The former is a condensation product of a mixture
of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about
7 mols of ethylene oxide, and the latter is a corresponding mixture
wherein the carbon atom content of the higher fatty alcohol is 12 to 13
and the number of ethylene oxide groups present averages about 6.5. The
higher alcohols are primary alkanols. Other examples of such detergents
include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linear
secondary alcohol ethoxylates made by Union Carbide Corp. The former is
mixed ethoxylation product of 11 to 15 carbon atoms linear secondary
alkanol with seven mols of ethylene oxide and the latter is a similar
product but with nine mols of ethylene oxide being reacted.
Also useful in the present compositions as a component of the nonionic
detergent are higher molecular weight nonionics, such as Neodol 45-11,
which are similar ethylene oxide condensation products of higher fatty
alcohols with the higher fatty alcohol being of 14 to 15 carbon atoms and
the number of ethylene oxide groups per mol being about 11. Such products
are also made by Shell Chemical Company.
Another group of liquid nonionics, also available from Shell Chemical
Company, Inc. under the Dobanol trademark include, for example, Dobanol
91-5, an ethoxylated C.sub.9 -C.sub.11 fatty alcohol with an average of 5
moles ethylene oxide; and Dobanol 25-7 an ethoxylated C.sub.12 -C.sub.15
fatty alcohol with an average of 7 moles ethylene oxide; etc.
Other highly useful nonionics are represented by the commercially
well-known class of nonionics which are the reaction product of a higher
linear alcohol and a mixture of ethylene and propylene oxides, containing
a mixed chain of ethylene oxide and propylene oxide, terminated by a
hydroxyl group. Examples include the nonionics sold under the Plurafac
trademark of BASF, such as a C.sub.13 -C.sub.15 fatty alcohol condensed
with 7 moles propylene oxide and 4 moles ethylene oxide, a C.sub.13
-C.sub.15 fatty alcohol condensed with 5 moles propylene oxide and 10
moles ethylene oxide, a C.sub.13 -C.sub.15 fatty alcohol condensed with 6
moles ethylene oxide and 3 moles propylene oxide, etc.
Generally, the mixed ethylene oxide-propylene oxide fatty alcohol
condensation products represented by the general formula
RO(C.sub.3 H.sub.6 O).sub.p (C.sub.2 H.sub.4 O).sub.q H,
wherein R is a straight or branched, primary or secondary aliphatic
hydrocarbon, preferably alkyl or alkenyl, especially preferably alkyl, of
from 6 to 20, preferably 10 to 18, especially preferably 12 to 18 carbon
atoms, p is a number of from 2 to 8, preferably 3 to 6, and q is a number
of from 2 to 12, preferably 4 to 10, can be advantageously used where low
foaming characteristics are desired. In addition, these surfactants have
the advantage of low gelling temperatures. Mixtures of two or more of the
mixed ethylene oxide-propylene oxide fatty alcohol condensation product
can be used as can mixtures of the mixed ethylene oxide-propylene oxide
condensation products with any of the above alkoxylated nonionics, or
mixtures of the ethoxylated nonionics can also be used.
In the preferred polylower alkoxylated higher alkanols, to obtain the best
balance of hydrophilic and lipophilic moieties the number of lower
alkoxies will usually be from 40% to 100% of the number of carbon atoms in
the higher alcohol, such as 40 to 60% thereof and the nonionic detergent
will often contain at least 50% of such preferred polylower alkoxy higher
alkanol.
Higher molecular weight alkanols and various other normally solid nonionic
detergents and surface active agents may be contributory to gelation of
the liquid detergent and consequently, will preferably be omitted or
limited in quantity in the present compositions, although minor
proportions thereof may be employed for their cleaning properties, etc.
With respect to both preferred and less preferred nonionic detergents the
alkyl groups present therein are generally linear although branching may
be tolerated, such as at a carbon next to or two carbons removed from the
terminal carbon of the straight chain and away from the alkoxy chain, if
such branched alkyl is not more than three carbons in length. Normally,
the proportion of carbon atoms in such a branched configuration will be
minor rarely exceeding 20% of the total carbon atom content of the alkyl.
Similarly, although linear alkyls which are terminally joined to the
alkylene oxide chains are highly preferred and are considered to result in
the best combination of detergency, biodegradability and non-gelling
characteristics, medial or secondary joinder to the alkylene oxide in the
chain may occur. It is usually in only a minor proportion of such alkyls,
generally less than 20% but, as is the case of the mentioned Terigtols,
may be greater.
When greater proportions of non-terminally alkoxylated alkanols, propylene
oxide-containing polylower alkoxylated alkanols and less
hydrophile-lipophile balanced nonionic detergent than mentioned above are
employed and when other nonionic detergents are used instead of the
preferred nonionics recited herein, the product resulting may not have as
good detergency, stability, viscosity and non-gelling properties as the
preferred compositions but use of viscosity and gel controlling compounds
can also improve the properties of the detergents based on such nonionics.
In some cases, as when a higher molecular weight polylower alkoxylated
higher alkanol is employed, often for its detergency, the proportion
thereof will be regulated or limited in accordance with the results of
routine experiments, to obtain the desired dete | | |
