Note: Descriptions are shown in the official language in which they were submitted.
1~4~388
This invention relates to supression of the caking
tendencies of linear alkyl aryl sulfonate detergents. More
specifically this invention relates to non-caking linear alkyl
aryl sulfonate detergent compositions in the form of dried
particulates.
The prior art was directed to the use of biodegradable de-
tergent compositions of the linear alkyl benzene sulfonate type.
Dried formulations containing substantial proportions of linear
alkyl benzene sulfonates however presented caking problems which
were not satisfactorily eliminated with presently knownanticaking
additives such as low molecular weight sodium sulfonates and
sodium silico-aluminate. Commercial spray dried products con-
taining substantial amounts of linear alkyl benzene sulfonates
were found to be particularly susceptible to caking.
It has now been found that by the addition of magnesium sul-
fate to linear alkyl aryl sulfonates, the resultant dried par-
ticulate products exhibit improved anti-caking characteristics.
It is therefore an object of this invention to provide a
.;.
linear alkyl aryl sulfonate detergent composition which provides
a non-caking product.
It is a further object of this invention to provide a par-
ticulate product of the aforesaid detergent composition which is
~ non-caking.
:
It is a further object of this invention to provide a spray
dried hollow spherical beaded product of the aforesaid detergent
composition which is non-caking.
The aforesaid as well as other objects and advantages will
be made apparent from a reading of the following detailed des-
cription.
~6~4~888
In accordance with the present invention the detergent com-
position may typicalIy have from about ~0 to 5~/0 by weight of
linear alkyl aryl sulfonates,for most commercial formulations,
and preferrably about 4~/0 by weight although more or less linear
alkyl aryl sulfonate may be used as required.
In order to produce a linear alkyl benzene sulfonate ~S),it
is one generally derived from the sulfonation and neutralization
of detergent alkylate in which the hydrocarbyl or alkyl radical
is derived from straight-chain or normal hydrocarbons instead of
polypropylene. To make the biodegradable detergent, conventional
reactions involve catalytic alkylation of benzene or some other
aryl compounds, such as toluene or xylene, with either an n-
alkene or an n-alkyl halide alkylating agent of the desired
'
molecular weight range, i.e., corresponding to a carbon content
of 8 to 18 carbon atoms. The alkylating agent can be derived
from petroleum distillate cracking or petroleum wax cracking,
catalytic dehydrogenation of n-paraffins, chlorination-dehydro-
chlorination of n-paraffins, ethylene polymerization, and chlori-
. nation of n-paraffins. In addition, the raw materials from which
the straight-chain stock is to be derived may be and often is,
subjected to is~normal separation processes, such as those in-
volving molecular sieves and urea clathration to produce a more
linear product than could otherwise be obtained.
The linear alkyl aryl sulfonates useful in this invention
are preferably linear alkyl benzene sulfonates wherein the alkyl
chain preferably has 8 to 18 carbon atoms and most preferably 10 -
to 15 carbon atoms. An alkyl chain which is a straight chain
containing 12 carbon atoms is generally very suitable.
The other essential ingredient in the composition of this
invention is magnesium sulfate. The magnesium sulfate as an
1~:)4~8~8
anticaking agent for linear alkyl aryl sulfonate detergents may
be present in amounts of from about 1 to 5.~/O by weight, and pre-
ferably in an amount of about 2.~ to 3.2% by weight; the weights
being on an anhydrous basis. The magnesium sulfates useful in
the compositions of this invention may be any one the commercial
grades of magnesium sulfate, such as by way of example, epsom
salts or magnesium sulfate heptahydrate. It is of course under-
stood that where the detergent product contains large percentages
of linear alkyl aryl sulfonates, higher percentages of magnesium
sulfate may be employed.
The products formed from the composition of the present in-
vention may be produced by known commercial methods such as spray
drying or drum drying. It is within the contemplation of this
invention that any form of particulate product formed from the
composition of this invention have good anti-caking character-
istics.
In a typical spray drying method, the composition of this
invention may be formed into a slurry, and the slurry then forced
through spray nozzles into towers wherein the small liquid part-
iculates are modified, solidified and dried as they contact a
stream or vortex of heated air. The composition is produced
thereby in the form of hollow, thin-walled spheres or beads ge-
nerally having low apparent bulk densities and characterized by
good solubility, good foaming properties, uniformity of particles
and which are essentially non-caking.
The composition may contain any of the other ingredients
usual in detergent compositions such as alkaline builder salts,
bleaches, optical brighteners, sequestering agents, soil suspend-
ing agents, colors, perfumes, bacteriocides and the like. Other
1~348888
organic detergents may be present in minor proportions provided
that they do not impair the performance of the composition of
the invention. In particular, ~ather stabilizers may be added;
examples are, fatty acyl ethanolamides, such as lauric mono-
ethanolamide.
The invention is further illustrated by the following exam-
ple which is not to be considered as limiting the scope of the
invention~ All percentages reported in the example are by weight
or unless otherwise indicated.
EXAMPLE
Five samples were prepared, slurried and spray dried by
conventional methods to produce hollow spherical beaded products
having the composition analyses as reported in Table 1 and the
physical analyses as reported in Table 2.
, . .
TABLE 1
Composition (%)
Component 1 2 3 4 5
LAS 43.243.0 36.3 41.740.3
NaCl 6.8 5.5 9.7 13.612.6
water 2.0 2.0 1.0 1.00.9
Anticake2 1.8 1.8 0.0 0.00.0
Anticake 0.8 1.3 0.0 0.00.0
Anticake -- -- -- -- 0.8
MgSO45~ 0.2 0.2 0.2 3.20.5
Filler7 R8. R8~ R8~ R8~ R8
notes:
1. sodium alkyl benzene sulfonate, molecular weight 339,
average alkyl is Cll 5
~4~8~3
2. 75% sodium xylene sulfonate, 250/o sodium toluene sulfon~e
3. hydrated sodium silico-aluminate
4. trisodium sulfosuccinate
5. anhydrous weight basis
6. estimated
7. sodium sulfate
8. remainder~
The spray dried hollow beaded products o~ samples 1-5 were
prepared from formulations containing 40 percent by weight of the
linear alkyl aryl sulfonates, and sample No. 4 contained 5 percent
by weight anhydrous of MgS04 as the heptahydrate. Samples 1 and 2
were produced in a spray dry tower wherein the tower air inlet
temperature was 815F. and the air outlet temperature was 210
to 225F. with a slurry pressure of 650 to 700 psig. For the
formulation of sample 3, the corresponding air inlet temperature
was 8250F., and the air outlet temperature was 225 to 2350F.
with a slurry pressure of 450 to 750 psig. For the formulation
of sample 4, the corresponding air inlet temperature was 825 F.,
and the air outlet temperature was 225F., with a slurry pressure
of 450 to 550 psig. For the formulation of sample 5, the air
inlet temperature was 820F, and the air outlet temperature was
225F, with the slurry pressure of 450 to 500 psig.
TABLE 2
Physical Properties
1 3 4 5
pH 7.27.3 5.5 7.7 7.7
Density2 0.210.20 0.26 0.23 0.24
Clarity3 hazy hazy clear clear clear
38
Particulate Size Distribution, % on U.S. Std. Sieve
~o. 20 0.6 2.0 0.0 0.2 0.0
~lo. 4016.833.4 8.9 38.4 24.8
No. 6037.533.8 51.7 ~6.1 52.2
~o. 8018.713.3 25.5 9.9 15.4
. 1008.5 5.4 6.6 ~ 3,7
No. 1206.4 3.9 3.7 1.5 2.0
pan 11.5 8.2 3.6 1.5 1.9
100.0100.01.00.0100.0100.0
notes:
1. 1% solution
2. g/cc.
3. 1% solution
The spray dried beaded product of each of the five samples
was evaluated to determine caking tendency as a function of water
content according to the method reported by Monick (i.e. J. A .
Monick, "Measuring Tackiness of Detergent Powders", Soap & Chem.,
Spec. 42 (6), pp. 49-53, 107, June 1966) . This procedure involves
applying pressure to a cylinder of powder contained in a mold to
form a cake, removing the mold, and determining the force required
to break the cake, A low breaking force is reported to correlate
with a low tendency toward caking. Previous studies have shown
that caking in detergent products increases with increasing
moisture content in the product. To obtain a caking profile, the
breaking force for each product is determined by varying water
contents. The water contents, determined as volatiles at 150C,
were adjusted by drying the products at 100C or by maintainingtbQ,
products in a humid environment and then allowing the products to
equilibrate in a closed jar overnight.
1~4~88
The results of the Monick tests are reported in Table 3.
' ,:
`, TABLE 3
Breaking force
Sample No. Water (%)(lb.)
.
1. 0.7 1.0
2.0 5~5
2.7 9.2
2. 0.7 0.0
2.0 3~0
2.4 8,52
3. 1.0 0.0
2.0 2'2
3.3 9'2
3~5 11.0
4. 1.0 0.0
1.9 0.0
2.7 0.0
3.8 1.5
4.6 4.0
5. 0.9 0.0
1.5 1.0
2.2 2.5
4.2 12.52
notes:
1. forming force, 141b. for two minutes at 80 F. (26.7 C)
2. partial breakup of cake observed
.
As indicated in Table 3, the caking tendencies of samples
1, 2, 3 and 5 containing known anticaking agents are generally
about the same with each of said samples requiring relatively
high breaking forces, indicating substantial caking for water
contents of about 3 percent. Sample ~o. 4, however, containing
no heretofore known anticaking agent, but containing 3.2 percent
magnesium sulfate, showed zero breaking force at 2.7 percent
water. A zero breaking force indicates that the product is non-
caking.
Although the invention has been described with reference to
certain preferred embodiments, it is not the intention of the
applicants to be limited thereby and certain obvious modifications
are intended to be included within the broad scope of the in-
vention as embodied in the following claims.
.
