Note: Descriptions are shown in the official language in which they were submitted.
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PARTICULATE WATER' DISPERSIBLE FREE FLOWING FABRIC SOFTENER
COMPOSITION AND PROCESS FOR MAKING SAME
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to water dispersible, free
flowing solid softening compositions for textiles and
textile fibers, and a process for their manufacture.
2. Description of the Related Art
The tendency for laundered textile fibers to acquire
rigidity and static charges is most pronounced when
the laundry product is a synthetic detergent.
Stiffness of the fibers and static charges combine to
impart a palpable harshness to the textile. Articles
of clothing, bed linens and the like, possessing such
harshness, are irritating to the skin and
uncomfortable to wear. In addition, they tend to
retain wrinkles and attract dirt and dust. These
undesirable consequences of laundering have been
overcome by the use of quaternary ammonium compounds,
among others. Quaternary ammonium compounds are
currently widely used to impart softness and
pliability to the textile and to diminish static
charges. Quaternary compound softeners may be a
component of the laundry detergent, may be added
separately to the wash water at some point in the
laundry cycle, or dispensed in the dryer.
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T,he utility of quaternary salts of bis-
(alkylamidoalkyl)ami.i~es especially those derived from
fatty acids, as softeners for textile fibers in
laundry applications, and a method for their
preparation, are set forth in U.S. Patent number
3,492,324. This patent teaches that the Quaternary
compounds are obtained as semi-solids or solids,
which are admixed with appropriate quantities of
water to form pastes. These pastes, which are
"pourable", may then further be admixed with water to
form dispersions suitable for incorporation onto
textiles or textile fibers for the purpose of
softening them.
Aqueous pastes are by their nature incapable of being
incorporated into powdered laundry products, without
deleteriously affecting the free flowing
characteristics of such products. Further, aqueous
pastes or dispersions suffer from handling, storing,
packaging, and shipping disadvantages.
Problems inherent in the use of such aqueous systems
include: storage instability due to changes in
temperature., which result in the separation of the
quaternary compound from the water; loss of
water due to evaporation, which alters the
concentration of softener in the mixture and results
in non-uniform application of the softener. In order
for formulators to use the paste itself, it must be
removed fronn the container and dispersed with
sufficient water to obtain a softening dispersion.
Bulk dispen:>ing of a paste under these cirmcumstances
is physically difficult, and results in losses of
paste itself" and inaccurate dispensing of softening
material.
A' .
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An alternative to the paste form of ~i~(alkylamidoalkyl)amine
quaternary fabric softening compounds is as an
aqueous dispersion. Such aqueous dispersions suffer
from the inherent problems of aqueous pastes, and in
addition, require the use of bulkier rigid metal or
plastic shipping containers, which increases the cost
of storage and transportation._
It is also known in the art that the dispersibility
in water of such quaternary fabric softening
compounds, and the stability of aqueous dispersions
thereof, may be enhanced by the addition of fatty
alcohols, e.g. U.S. Patent number 4,102,795.
The literature does not reveal the use of bis-Ealkylamido-
alkyl)a~nizie- quaternary fabric softeners in
particulate or powder form. The physical properties
of dialkyldiamido quaternary compounds e.g.; high
viscosity in the molten state; melting range, on the
order of 100~C; and a decomposition temperature of
about 120~C; are not conducive to preparation of
particulates or powders. We have, however,
discovered a convenient method for the preparation of
dialkyldiamido quaternary fabric softening compounds
in the form of particulates or powders.
~~,i.Y
.....<.~'~
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:iUMMARY OF THE INVENTION
The present invention is directed to a particulate,
water dispersible, free flowing fabric softener
composition. Such a composition may be obtained by
admixing an effective Quantity of a processing aid, such
as a polyoxyalkylene derivative, with a bis(alkylamidoalkyl)amine
quaternary compound, melting them, and atomizing the
molten mixture in conventional equipment appropriate for
obtaining particulate material from a molten mixture.
The particulate product obtained permits the use of bis(alkyl-
amidoalkyl)amine quaternary fabric softening compound in
solid laundry products without altering their free
flowing characteristics. Being a solid, the particulate
product does not suffer from the physical handling
drawbacks associated with pastes of bis(alkylamidoalkyl)amine
quaternary compounds, while at the same time, being
easily dispersed in water.
DETAILED DESCRIPTION OF THE INVENTION
T h i s i n v a n t i o 1 ~ r a 1 a t a s t o bis ( alkylamidoalkyl ) amine
quaternary
fabric softening compositions in the form of free
flowing, water dispensable particulates or powders. The
art in the field of dialkyldiamido quatenary compounds
which function well as fabric softeners is directed to
non-powders, i.e., aqueous pastes or dispersions. The
physical properties of dialkyldiamido quaternary
compounds are conducive to their preparation as aqueous
pastes or dispersions and they are marketed and shipped
to formulators :in these forms.
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_ 1341110
The process for the manufacture of the bis(alkylamidoalkyl)amine
quaternary fabric softening compounds of this invention
is taught e.g., by U.S. Patent number 3,492,324. Thus,
fatty acids are reacted with diethylenetriamine in a
m o 1 a r a t i o o f 2 : 1 . T h a r a s a 1 t i n g bis ( alkylamidoethyl )
amine is
methylated by reaction with formic acid and/or
forraldehyde, and the resulting bis(alkylamidoethyl)amine
is quaternized with conventional reagents,
e.g., dimethyl sulfate.
It is also well i;nown in the art relating to the
quaternization of amines that benzyl chloride, methyl
chloride and dimethylsulfate are suitable quaternizing
agents for tertiary amines, such as the
bis(alkylamidoethyl.)amine described above. Further, it
is also well known in the ==.rt that methyl chloride may
be reacted with secondary amines such as the bis-
(alkylamidoethyl)ami.ne described above, in a mole ratio of
2:1 respectively, to produce a quaternary compound
useful for fabric softening.
In order for dialkyldiamido quaternary compounds to be
more widely usei.'ul as fabric softeners, especially in
free flowing laundry detergent compositions, end to
overcome the problems inherent in shipment, storage and
use as aqueous pastes and dispersions, a particulate
form of the dial.kyldiamido quaternary compound is
desirable. Conventional atomizing equipment to produce
such particulate~s includes spray drying, spray
congealing, and prilling devices among others. Spray
drying and spray congealing, for example, necessitate
pumping liquifie~d quaternary compounds through narrow
orifices under sufficient pressure to produce fine
droplets; these processes have proven to be relatively
expensive and operationally difficult.
.li
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The viscosity of the molten dialkyldiamido quaternary
compound is such that it is incapable of being pumped
neat at the maximum allowable temperature, i.e:, the
temperature of incipient decomposition. That is, at the
maximum permissible temperature, the viscosity of the bisfalkyl-
amidoalkyl)amine quaternary compound itself exceeds the
physical limitations of conventional pumps, within the
limits of economic practicality. Thus the pump
cavitates or otherwise fails to transfer the molten
material from the input reservoir to the output. This
condition is e:Kacerbated when the output is a narrow
constriction o:r orifice, as is the case in conventional
atomization equipment.
Conventic:~al atomization equipment includes devices such
as spray nozzles, rotating disks, or shot towers. Some
of these device's function by forcing a liquid through
narrow orifices to produce fine droplets. The droplets
solidify to form the particulate. Cooling, e.g., by
means of refriF;erated air or other gasses, may be
provided to aid solidifcation of said droplets. The
range of particles in the particulate thus produced is
nominally from 10 to 900 microns in diameter, with the
preferred range~ for the use of this invention averaging
from 100 to 30C1 microns in diameter. The orifice sizes
necessary to produce this range of particulate will vary
with tha viscosity of tha moltan bis(alkylamidoalkyl)amine
quaternary compound, the type of atomization, and the
characteristics. of the ancillary equipment used to force
the liquified S~uaternary compound through those
orifices.
:a
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The orifice sizes may range from about 0.1 to b
millimeters in diameter.
The force necessary to atomize a liquid, by whatever
means, may be supplied by mechanical pumps or by
b centripetal force, as is the case of spinning disks.
Thus, fatty acid derived dialkyldiamido quaternary
compounds, which are ordinarily solids at room
temperature, must be liquified to utilize atomization
equipment and thus form a particulate.
IO Liquification of fatty acid derived bis(alkylamidoalkyl)amine
quaternary compounds may be accomplished by heating to
100 to 120°C. Higher temperatures usually result in
degradation of the product as evidenced by discoloration
or browning.
16 At approximately 120°C, the viscosity, i.e., the
a b i 1 i t y t o p a s s t h r o a g h a n o r i f i c a , o f bis
(alkylamidoethyl ) amine
is extremely high, and has
been measured at over 160,000 centipoises. This
viscosity is such as to incapacitate conventional
20 mechanical pumps, within the limits of economic
practicality, necessary to the atomization process, as
has been described in the foregoing. Attempts to reduce
viscosity by me>ans of increasing the temperature results
in decomposition of the quaternary compound itself. Of
25 course, water could be added to dilute the molten mass,
and thus reduce the viscosity. However, additional
water sufficier,,t to facilitate pumping results in
products with unacceptably high water content. Such
high water content causes the powder particles to
30 agglomerate resulting in solids which are no longer free
flowing, and which on standing tend to form solid
masses.
-8- 1341110
This tendency of a powder to form solid masses is
characterized as "tack". Tack may be evaluated by
determining the force, in pounds, necessary to break a
formed cake of the respective material. The cake is
b formed by comF~acting 450m1 of product in a circular
mold, 8.57cm in diamter and 12.7cm high, with a 9.98kg
piston, at room temperature for 2 minutes.
Solvents other than water, for example isopropyl
alcohol, may be added to reduce the viscosity of the
molten quaternary compound. Sufficient quantities of
isopropyl alcohol to facilitate pumping also result in
unacceptably high levels of "tack". Further, isopropyl
alcohol, being: flammable, presents additional problems
in commercial scale equipment. There is an inherent
explosion hazard, and the vaporized isopropyl alcohol
must be recovered from the vapor state in an
environmentally acceptable manner. The equipment
required to accomplish this recovery, i.e., by
condensation, is both costly and cumbersome.
It has been discovered that by incorporating an
effective amount, preferably 10% by weight of a
polyoxyalkylene derivative processing aid, into molten
dialkyldiamido~ quaternary compounds, a particulate, free
flowing water dispersible fabric softener composition
may be obtained by conventional atomization techniques.
The addition o~f polyoxylalkylene derivatives
significantly reduces the viscosity of the molten
quaternary compound, facilitating atomization with
conventional equipment, while not decreasing the free
flowing characteristics or the dispersibility of the
resultant particulate.
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This is evidenced by little significant change in either "tack"
or dispersibility, when the polyoxyalkylene processing aid is
incorporated into the bis(alkylamidoalkyl)amine quaternary
compound.
The particulate, water dispersible, free flowing fabric
softener composition of the present invention comprises a
bis(alkylamidoalltyl)amine-derived quaternary compound having
the structural formula:
R
i~
0
II N ~ X O (I)
R~ -- C -NH - ( CHZ ) n 2
R
where:
R1 is a Ct~-C22 alkyl group
R2 is a C:L-C3 alkyl group
R3 is a C1-C3 alkyl group, a phenyl group or a benzyl
group
n is 1-6
X is a monovalent anionic residue of an alkylating
agent.
In a preferred embodiment the quaternary compound is
characterized b:y R1 being C13-C21 alkyl and X being a
methosulfate or chloride radical. More preferably, the
quaternary compound is defined by R1 being C15-C1~ and X being
a methosulfate or_ chloride radical.
_ g _
;:, ? ?;s
w::
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The free flowing fabric softener composition
additionally includes a polyoxyalkylene derivative useful as a
processing aid in the preferred concentration ranges recited
above. The polyoxyalkylene derivative processing aid is a
compound having the structural formula:
0
R-C-Y- ( CHz CH-0-) n Z ( I I )
R' W
a compound having repeating structural formula
R"-(OCH, CH-)n OR"' (III)
R'
or mixtures the~__~eof wherein:
n is an integer of 0 to 30;
R is a C6 to C22 alkyl group;
R' is hydrogen or a C1-C3 alkyl group;
R " is hydrogen, C5-C22 alkyl or isostearyl;
R " ' is hydrogen, C5-C22 alkyl or isostearyl;
Y is oxygen or 0-CH2-CHCH20-
W=1 cr 2 ;
0-
Z is hydrogen or a substituent of the formula:
HO- ( CHz CHz 0 ) x ( 0-CHz CHz ) y-OH
H
0 ~ C ( OCH CH ) -OH
z z z
CH
1 z
- 9a -
1341 ~~~
where x, y and z are independently integers of 2 to 10. A
preferred class of polyoxyalkylene compounds are those
characterized by mixture of compounds having the structural
formula II where R' is hydrogen and methyl groups.
In a preferred embodiment the polyoxyalkylene derivative
is the reaction product of up to 30 moles of ethylene oxide
with the monog:Lyceryl ester of coconut fatty acid. More
preferably, the reaction product of approximately 30 moles of
ethylene oxide and 1 mole of the monoglyceryl ester of a
coconut fatty acid is employed as the processing aid.
Other preferred embodiments of the polyalkylene
derivative processing aid, within the broad classes mentioned
above, that can be used include ethoxylated sorbitan oleate
derivatives and ethoxylated fatty alcohols.
Thus, =Ln another preferred embodiment, the
polyoxyalkylene derivative processing aid is the adduct of 20
moles of ethylene oxide and sorbitan monooleate. In another
embodiment, the processing aid is the adduct of 20 moles of
ethylene oxide and isostearyl alcohol.
The amount of polyoxyalkylene derivative utilized is
that amount effective as a processing aid. That amount is
usually up to about 15% by weight of the
bis(alkylamidoalkyl)amine-derived quaternary compound.
Preferably, about 2% to about 15% by weight of the polyalkylene
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s,
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derivative, based on the weight of the quaternary compound, is
utilized. Less than 2% by weight tends to be ineffective in
reducing viscosity. More than 15% by weight of the
polyalkylene derivative, based on the weight of the
bis(alkylamidoalkyl)amine-derived quaternary compound, tends to
increase the "tack" of the particulate. More preferably, about
2% to about 12% by weight of the polyalkylene derivative, based
on the weight of the quaternary compound, is employed. More
preferably, 10% by weight of the polyalkylene derivative is
used.
The preferred fatty acid derived bis(alkyl-
amidoalkyl)amine-derived quaternary compound is that derived
from hardened tallow fatty acids as in Example 1 below.
Another aspect of the present invention involves a
process for making a bis(alkylamidoalkyl)amine-derived
quaternary compound fabric softener in particulate form.
In thi:~ process a liquefied blend of the
bis(alkylamidoal:kyl)amine-derived quaternary compound having
the structural formula I where the radicals have the meanings
given for the formula and a polyoxyalkylene derivative
processing aid selected from the group consisting of compounds
have the structural formula II, compounds having the structural
formula III and :mixtures thereof are formed. In the forming of
this blend enough polyoxyalkylene derivative is included to
insure pumpability of the quaternary compound.
The process includes the further step of atomizing the
liquefied blend to form particulates.
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1341110
To illustrate the efficacy of this invention, the
following non-limiting examples are set forth.
EXAMPLE 1
Bis(hard tallowamidoethyl)dimethyl ammonium methosulfate
prepared from hardened tallow fatty acids, following the
teachings of U.S. Patent Number 3,492,324, was melted at 100°C
and atomized through a nozzle having an orifice 1.2 mm in
diameter at a preasure of 2000 psi. Only a small quantity of
particulate was obtained before pumps and lines became plugged,
rendering the equipment inoperable. Residual isopropanol from
preparation of the quaternary compound was removed by vacuum
drying at 40°C.
EXAMPLE 2
To 90 parts of the quaternary compound of Example 1 were
added 10 parts of the adduct of 30 moles of ethylene oxide and
glycerol mono cocoate, (Varonic LI-63, Sherex Chemical Company,
Dublin, OH). The mixture was melted at 100°C and atomized
through the ids~ntical equipment and under the identical
conditions of Example 1. The atomized droplets were congealed,
in air, at a temperature of 15 to 21°C and a relative humidity
of 50~. The congealed particulate having a particle size range
averaging from 100 to 300 microns in diameter was subsequently
vacuum dried as in Example 1.
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si
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EXAMPLE 1
Dialkyldiamidoethyl methyl ammonium methosulfate
compound prepared from hardened tallow fatty acids ,
following the teachings of U.S. Patent number 3,492,324,
was melted at 110°C and atomized through a nozzle
having an oriicice 1.2 microns in diameter at a pressure
of 2000 psi. The atomized droplets were congealed, in
air, at a temperature of 15 to 21°C and a relative
humidity of 50%. The congealed particulate having a
particle size range averaging from 100 to 300 microns in
diameter was ~.ubsequently vacuum dried at 40°C to
remove residual isopropanol, from the preparation of the
quaternary compound.
EXAMPLE 2
To 90 parts of the quaternary compound of Example 1 were
added 10 part~o of the adduct of 30 moles of ethylene
oxide and glycerol mono cocoate, (Varoni ~ LI-63, Sherex
Chemical Company, Dublin, OH). The mixture was melted
at 110°C and atomized through the identical equipment
of Example 1. Only a small quantity of particulate was
obtained before pumps and lines became plugged,
rendering the equipment inoperable. Residual
isopropanol from preparation of the quaternary compound
was removed a.. in Example 1.
- 11 - 1341 110
EXAMPLE 3
To 90 parts of the quaternary compound of the Example 1
were added 10 parts of isopropyl alcohol and 10 parts of
ethoxylated sorbitan mono oleate, (Tween~80, ICI
Americas, Wilu~ington, DL; 20 moles of ethylene oxide per
mole of sorbitan mono oleate). The mixture was melted
at 110~C, and atomized, congealed and vacuum dried as
~in Example 1.
EXAMPLE 4
90 parts of the quaternary compound of Example I were
admixed with 10 parts of ethoxylated isostearyl alcohols
(Arosurf~AA 66E-20, Sherex Chemical Company, Dublin, OH
moles of ethylene oxide per mole of isostearyl
alcohol), and 10 parts of isopropyl alcohol. The
15 mixture was melted at 110~C, atomized, congealed and
dried as in Example 1.
VISCOSITY:
The viscosities of t:he particulates obtained by
atomization of Examples 1 to Example 7 were determined
20 on a Brookfield Viscometer (Thermosel) using a #34
spindle (Brookfield Engineering Laboratories, Inc.
Staughton, MA). These data are presented in Table 1:
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Table 1
Product of Example Temperature~Cl Viscosity (CPS)
1 120 160,000
2 120 735
3 120 260
4 120 170
lTemperature of melted of quaternary compound (and
processing aid).
It can be observed from these data that a reduction of
viscosity of at least 200 fold is obtained by the use of
processing .aids. Example 1, without processing aid,
overwhelmed the physical capability of the spray
congealing equipment (See Example 1).
Dispersibilit~:
The dispersibility in water of the particulates of
Example 1 t~o 4 were determined by visual inspection of a
mixture of ~D.3 grams of product in 100 grams of water,
after agitation at 32~C for 10 minutes. The results
are presented in Table 2:
-ls- 134111fl
TABLE 2
Product of Example Dispersibilitv
1 lunacceptable (not dis-
persed)
2 2acceptable (dispersed)
3 acceptable (dispersed)
4 acceptable (dispersed)
lUnacceptable dispersions contain solid clumps and
clear areas
2Acceptable dispersions are uniformly cloudy
throughout
The dispers:ibility of the particulate obtained by the
use of a processing aid is significantly better than
when no processing aid is present as in Example 1.
Tack:
The "tack" of the particulate of Example 1 to 4 was
evaluated by determining the force in kilograms
necessary to break a formed cake of the resepective
material. '.Phe cake is formed by compacting 450 ml of
product in a circular mold 8.57cm in diameter and 12.?cm
high, with <i 9.98kg piston, at room temperature for 2
minutes. The results are presented in Table 3.
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Table 3
Product of Example Force in kg. necessary to Break Cake
1 1.86
1.40
3 1.86
4 3.67
1* 3.44
2* >9.0
*Samples of product not vacuum dried at 40°C, i.e.,
containing c:a. b% by weight of isopropanol.
The presence of isopropanol significantly increases the
"tack" i.e., reduces the ability of the particulate to
flow freely while the preferred processing aids do not.