Note: Descriptions are shown in the official language in which they were submitted.
~2~
GRANULAP~ D~TERGENT S~OMPOSITIONS
HAVING IMPROVED SOLUBII.~ Y
Jeffrey E. Moore
Brett A. Evans
Richard Hansen
Technical Field
The present invention re~ates to granMlar detergent
compositions containing a specific mixture oP alkylben-
zene sulfonate surfactant, alkyl sulfate surfactant,
alkali metal silicate and water-soluble sulfate, The
compositions are prepared by drying, preferably by
spray-drying, an aqueous slurry comprising the above
components. While the composi ions preferably also
contain detergent builder materials, there should be
relatively little or no pyrophospha~e or anhydrous Form
I tripolyphosphate builder in that portion of the
composition prepared by drying th~ slurry comprising the
~ sulfonate and sulfate surfactants, silicate and sulfate.
; Mixtures of alkylbenzene sulfonate and alkyl sulfate
surfactants are desired for optimum detergency perform-
ance. However, such mixtures tend to gel on contact with
water. This can result in poor solubility of granules
; having high level~ of alkylbenzene sulfonate and alkyl
sulfate surfactants, particularly when such granules are
incorporated in dense detergent compositions.
It has now been found that very soluble granular
detergent compositio~s containing high levels of alkyl-
benzene sulfonate and alkyl sulfate surfactants can be
obtained by drying an aqueous slurry comprising the
surfactants, silicate in a weight ratio of surfactant to
silicate within the range of from about l.5:l to about
6:l, sulfate and relatively little or no pyrophosphate
or anhydrous Form I tripolyphosphate detergent builder
material. In preferred compositions, these soluble
detergent granules are admixed or agglomerated with
builders and other optional detergent ingredients.
Particularly preferred compositions are obtained by
admixing the soluble granules with builders, compacting
the admix at relatively low pressures (e.g., about 20 to
about 200 p5i), and optionally admixing additional
builders and other ingredients to provide finlshed
granular deter~ent compositions.
ackground Art
U.5. Patent 4,028,283, Murata et al~ issued June 7,
1977, discloses granular detergents containing surfac-
tants having a tendency to cake and an anticaking agent
formed by reacting polyethylene glycol with an acid
anhydride. The compositions can also contain 0-20% of
other surfactants such as alkylbenzene sulfonates.
Spray-dried detergents containing mixtures of alkyl-
benzene sulfonate and alkyl ethoxy sulfate surfactants,
silicate and builders are exemplified.
U.S. Patent 4,141,841, McDanald, issued February
27, 1979, discloses granular detergents containing
particulate antistatic/softening additives. In Example
8, the particles are mixed with spray-dried base granule
containing about 27~ of a mixtuxe of alkylbenzene sul-
fonate and alkyl ethoxy qulfate surfactants, 18% sili-
cate and about 22~ sodium tripolyphosphate.
Japanese OPI 106509, publ shed August 21, 1979~
discloses spray-dried granular detergents containing
15-40% surfactant, 5-20~ silicate and no more than 12%
phosphate. The compositions are said to have good
physical properties and to cause less deposition of
insolubles on clothes.
Japanese OPI 72998 and 72999, published April 25,
1985, disclose dense granular detergents formed by high
shear mixing of alkylbenz~ne sulfuric acid and alkyl
sulfuric acid with sodium carbonate and water to cause
neutralization, admixing other ingredients such as
builders, and then crushing and yranulating the mixture.
~2~
Summary_of the Invention
This invention relates to a granular detergent
composition prepared by:
(1) forming base granules comprising, by weight:
(a) from about 30~ to about 85% of a mixture
of a C11-C13 alkylbenzene sulfonate surfactant and a
C12-C16 alkyl sulfate surfactant in a wleiyht ratio of
sulfonate surfactant to sulfate surfactant of from about
4:1 to about 1:4;
(b) an alkali metal silicate having a molar
ratio of SiO2 to alkali metal oxide of from about 1.0 to
about 3.2
the weight ratio of ~a) to (b) being from about 1.5:1 to
about 6:1;
(c) from about 10~ to about 60% of a water-
soluble sulfate; and
(d) from 0% to about 20% of a pyrophosphate
or anhydrous Foxm I tripolyphosphate detergent builder
material, or mixtures thereof,
said ~ase granules prepared by drying an aqueous slurry
comprising the above components;
(2) admixing said base granules with from 0% to
about 300%, by weight of the base granules~ of a deter-
gent builder material:
(3~ compacting said admix at a pressure of from
about 20 to about 200 psi;
(4) granulating the rPsulting compacted admix; and
(5~ admixing an additional 0% to about 300~, by
weight of the base granules, of a detergent builder
material;
said composition having a bulk density of from about
0.55 to about 1.2 g/cc and an average particle size of
from about 20 to about 1500 microns.
~ ;27~19
-- 4 -- -
Detailed Description of the Invention
The granular detergent compositions of the present
invention contain from about 30% to a~out 85~,
preferably from about 35~ to about 60~, more preferably
from about 40~ to about 50%, by weight of a mixture of
Cll-C13 alkylbenzene sulfonate surfactant and ~12-C16
alkyl sulfate surfactant in a weight ratio of sulfonate
surfactant to sulfate surfactant of from about 4:1 to
about 1:4, pxeEerably fxom about 3:1 to about 1:3, more
preferahly from a~out 2:1 to about 1:2.
Sulfonate surfactants useful herein are the water-
soluble salts, particularly the alkali metal, ammonium
and alkanolammonium (e.g., monoe~hanolammonium or tri-
ethanolammonium) salts of alkylbenzene sulfonates in
which the alkyl group contains from about 11 to about 13
carbon atoms, in straight chain or branched chain con-
figuxation, e.g., those of the type described in U.S.
Patents 2,220,099 and 2,477,383. Preferred are linear
straight chain alkyl-benzene sulfonates in which the
average number of carbon atoms in the alkyl group is Erom
about 12 to about 13.
Useful alkyl sulfate surfactants are the water-
soluble salts, particularly the alkali metal, ammonium
and alkanolam~onium (e.g., monoethanolammonium or
triethanolammonium~ salts of C12-C16 linear or ~ranched
alkyl sulfates. Preferred are those containing a
C12-C15, especially C14-Cl5, linear ~l~yl group.
The compositions herein can a~so contain minor
amounts ~generally less than about 30~, but preferably
less than about 15~, by weight of the above sulfvnate and
sulfate surfactants3 of other detergent surfactants Xnown
in the art. These can include anionic, nonioni~,
cationic, ampholytic and zwitterionic surfactants, such
as those disclosed in U.S. Patent 3,919,678, Laughlin, et
al, issued December 30, 1975,
~%~
~ 5 --
The compositions ~f the present invention also
contain an alkali metal silicate having a molax ratio of
SiO2 to alkali metal oxide of from about 1.0 to about
3.2, preferably from about 1.6 to about 2.4~ Sodium
silicate, particularly having a molar ratio of from about
1.6 to about 2.2, is preferred.
The alkali metal silicates can be purchased in
either liquid or granular form. Silicate solutions or
slurries can conveniently be used to avoid haviny to
l dissolve the dried form in the aqueous slurry (e.q.,
crutcher mix) of the components herein.
In addition, the weight ratio of the alkylbenzene
sulfonate plus alkyl sulfate surfactants herein to the
alkali metal silicate should be from about 1.5:1 to
about 6:1, preferably from about 2:1 to about 4:1, more
preferably from about 2.5:1 to about 3.5:1.
The present compositions fur~her contain from about
10g to about 60~, preferably from about ~0~ to about
50%, by weight of a water~soluble ~preferably sodium)
sulfate. Sodium sulfate is usually formed during the
sulfationtsulfonation and neutrali~ation steps in the
production of the alkylbenzene sulfonate and alkyl
sulfate surfactants herein.
The compositions herein are prepared by drying an
aqueous slurry comprisi~g the components, The slurry
generally contains from about 25~ to about 70%, prefer-
ably from about 40~ to about 60%, water, whereas the
dried granules initially contain from about l~ to about
10%, preferably from abouk 1~ to about 3%, water~ Tlle
drying operation can be accomplished by any convanient
means, such as by using spray-drying towers, both
counter-current and co-current, fluid heds, flash drying
equipment, or industrial microwave or oven-drying equip~
ment. These are more fully described in U.S. Patent
4,019,998, Benson et al, issued April 26, 1977,
~7~
The granular detergents herein are very soluble in
the wash water even though they contain high levels of
alkylbenzene sulfonate and alkyl sulfate surfactants
Good solubility is obtained when the weight ratio of
total sulfonate plus sulfate surfactant to silicate is
within the about 1.5:1 to about 6:1 range specified
above. While not intending to be limited by theory, it
is believed that this relatively high level of silicate
provides structure and help~ to maintain integrity o~ the
lo high surfactant granules and that this min~mizes gelling
when the surfactants contact the wash water. However, if
the ~ilicate level becomes too high ~e.g., a ~urfactant
to silica~e ratio of l:l), overall solubility can suffer
due to the formation of silicate insolubles. On the
lS other hand, granules having a sur~actant to silicate
ratio of, for example, a: 1, have insufficient structure
and tend to be too mushy at these high surfactant
levels.
For good solubility, the amount of pyxophosp31ate or
anhydrous Form I tripolyphosphate deteryent builder
material in the portion of the granular detergent
obtained by drying an aqueous slurry of the essential
components herein should also be minimized. Thus the
compositions can contain from 0~ to about 2~, preferably
from 0~ to about 15~, more preferab7y from 0~ to about
10%, by weight of such detergent builder material, or
mixtures thereof. Most preferably, the compositions are
substantially free of such detergent builder (e.g., they
contain less than about 5~, preferably less than about
3%, by weight of builder~.
The compositions can contain up to about 60~,
preferably ~rom about 1% to about 45~, by weight of
other detergent builders, including those described in
U.S. Patent 3,925,262, Laughlin et al, is~ued December
9, 1975. Builders are generally selec~ed from the various
water-soluble alkali
~A
metal, ammonium or substituted ammonium phosphates,
polyphosphates, phosphonates, polyphosphonates, carbon
ates, borates, polyhydroxy sulfonates, polyacetates,
carboxylates, and polycarboxylates. Preferred are the
alkali matal, especially sodium, salts of the above.
Specific examplPs of inorganic phosphate b~ilders
are sodium and potassium tripolyphosphalte ~Form II or
hydrated Porm I), polymeric metaphoslphate having a
degree of polymerization o~ from about 6 to 2.1, and
orthophosphate. Examples of polyphosphonate builders
are the sodium and potassium salts of ethylene diphos-
phonic acid, the sodium and potassium salts of ethane .
1-hydroxy~ diphosphonic acid and the sodium and
potassium salts of ethane, 1,1,2-triphosphonic acid.
Other phosphorus builder compounds are disclosed in U.S.
Patents 3,159,581 3,213,030; 3,422,021; 3,422,137;
3,400,176; and 3,400,148~
Examples of nonphosphorus, inoxganic builders are
sodium and potassium carbonate, bicarbonate, ses~uicar-
bonate, and tetraborate decahydrate.
Water-soluble, nonphosphorus organic builders
useful hexein include the various alkali metal, ammonium
and substitu~ed ammonium polyacetates, carboxylates,
polycarboxylates and polyhydroxy sulfonates. Examples
of polyacetate and polycarboxylate builders are the
sodium, potassium, lithium, ammonium and substituted
ammonium salts of ethylene diamine tetraacetic acid,
nitrilotriacetic acid, oxydisuccinic acid, mellitic
acid, benæene polycarboxylic acids, and citric acid.
Polymeric polycarboxylate bui~dexs are also
described in U.S. Patent 3,30~,067, Diehl, issued March
7, 1967. Such materials include the water-soluble salts
of homo- and copolymers of aliphatic carboxylic acids such
as maleic
~7~
-- 8 --
acid, itaconic acid, mesaconic acid, fumaric acid,
aconitic acid, citraconic acid and methylenemalonic
acidO
Other useful builders herein are sodium and potas~
sium carboxymethyloxymalonate, carboxymethyloxysuc-
cinate, cis-cyclohexanehexacarboxylate, cis-cyclopen
tanetetracarboxylate, phloroglucinol trisulfonate, and
the copolymers of maleic anhydride with vinyl methyl
ether or ethylene. -..
Other suitable polycarboxylates are the polyacetal
carboxylates described in U.S. Patent 4,144,226, issued
March 13, 1979 to Crutchfield et al, and U.S. Patent
4,246,495, issued March 27, 1979 to Crutchfield et al,
These polyacetal carboxylates can be prepared by bringng
together under polymerization conditions an ester of
glyoxylic aci.d and a polymerization initiator. The
resulting polyacetal carboxylate ester is then attached to
chemically stable end groups to stabilize the polyacetal
carboxylate against rapid depolymerization in alkaline
solution and converted to the corresponding salt.
:
A preferred phosphate builder is Form II sodium
tripolyphosphate (STPj (pre~erably anhydrous). A
preferred builder for use in compositions that a.re
substantially free of phosphate builders is soditLm
citrate.
When admixed, the builders herein should have the
same particle size as the remainder of the composition,
as described hexeinafter.
~he above granular detergent compositions can be
used as is as finished detergent compositions or as
detergent additive compositionsO However, they are
preferably used as (and hereinafter referred to as~
detergent base granule~ which are then admixed or
agglomerated with builder material and with other
~v
optional ingredients to provide finished detergent
compositions exhibiting good solubility. Such finished
compositions can comprise by weight from about 5% to
about 50%, preferably from about 10% to about 40%, more
preferably from about 12% to about 25%, of the alkylben-
zene sulfonate and alkyl sulfate surfactants herein and
from about 5% to about 95%, preferably from about 10% to
about 85%~ more prefexably from about 15% to about 75%~
of detergent builder material, such as de~cribed above.
lG However, for best solubility, the amount of pyrophos-
phate and anhydrous Form I tripolyphosphate should be
minimized, i.e., the finished compositions preferably
contain from 0% to about 20%, preferably from 0% to
about 10%, of such material, or mixtures thereof.
The compositions can also contain minor amounts,
generally less than 30%, preferably less than 20%, by
weight of other ingredients usually included in deter-
gent compositions. These include auxiliary detergent
surfactants, color speckles, bleaching agent~ and
bleach activators, suds boosters or suds suppressors,
antitarnish and anticorrosion age~ts, soil suspending
agents, soil release agentst dyPs, fillers, optical
brighteners, germicides, pH adjusting agents, nonbuilder
alkalinity sources, enzymes, enzyme-stabilizing agents
and perfumes.
Agglomeration can be accompli~hed by agitating in
the presence of a sllitable binder (e.g., in a fluidized
bed, tumble mixer, or a rotating drum or pan) or by
mechanically mixing under pressure (e.g., extruding,
pressing, milling, compacting or pell~ti~ing). Final
sizing can then be achieved by grinding and screening.
In a preferred embodiment, the detergent base
granules are admixed with from 0~ to about 300%, pre-
ferably from abc~ut 25% to about 200~, more preferably
from about 50~ to about 150%, by weight of the base
granules, of a detergent builder material such as
~2~
-- 10 --
described above. The resulting admix is th~n preferably
compacted at a relatively low pressure of from about 20
to about 200, preferably from about 40 to about 150,
more preferably from about 50 to about 100, pounds per
square inch (psi~. The composition is then preferably
admixed with an additional 0% to about 300%, preferably
from about 25~ to abou 200%, more preferably from about
50~ to about 150~, by weight of the base granules, of a
detergent builder material. The above levels and types
of builder material and compaction pressure are prefer-
ably selected so that the final detergent composition
has a bulk density of from about 0.55 to about 1.2;
preferably from about 0.65 to about 1.1, more preferably
from about 0.7 to about 0.9 g/cc and an average particle
size of from about 20 to about 1500 microns, preferably
from about 50 to about 1200 microns, more preferably
from about 100 to about 800 microns.
The above compaction step is preferably accom-
plished by using equipment that applies a relatively
uniform compaction pressure, for example, by using
compaction rollers with smooth (i.e., noncorrugated3
surfaces. After compaction, the composition is prefer-
ably granulated and screened to provide an average
particle size similar to that desired for the final
composition.
The following nonlimiting examples illustrate the
detergent compositions of the present inven~ion~
All percentages, parts and rat~os are by weight
unless otherwise specified.
Example I
The following granular detergent composi~ion was
prepared.
Base Granules
Grams Final Composi-
Weight ~ tion ~er use
Sodium C13 linear alkyl-
benzene sulfonate 22.1 5.110
Sodium Clq 15 alkyl 5ulfate 22.1 5O110
Sodium silicate (1.6 ratio)13.7 3.172
Sodium sulfate 32.2 7.455
Polyethylene glycol
(m. w~. 8000) 1.5 0.340
Sodium polyacrylate
(m. wt. 4500) 2.0 0.453
C12-13 alcohol poly-
ethoxylate (6) 3.0 0.680
Sodium diethylenetriamine
pentaacetate 1.5 0.340
Moisture 2.0 0.462
23.12Z
Preblend
Base granules 23.122
15 Sodium tripolyphosphate hexahydrate
~powdered fo~m) 20.576
43.698
Admix
Preblend 43.698
20 Sodium tripolyphosphate hexahydrate
~granular) 19.429
Dye 0-003
Brightener 0.613
Suds suppressor prill comprising
dimethylsilicone, silica, sodium
tripolyphosphate and polyethylene
glycol ~MW = 8000) 1.703
Protease 2.044
Sodium carbonate 4.000
71.490
Spray-On
Admix 71.490
Mineral oil 0O710
72.200
- 12 -
The base granules were produced by spray-drying an
aqueous crutcher mix of the components on a ten foot
tower using a crutcher temperature of 200aF, a si2e 3-1/2
nozzle to make fine granules, and silicone deaeratants.
If the base granules contained more thall 2~ moisture, a
second drying stage on a continuou~ fluid bed was per-
formed to reduce moisture to 2~
The base granules were then admixed with powdered
STP hexahydrate to form the preblend. The preblend was
compacted at 50 psig roll pressure on a 4 in. by l0 in.
chilsonator, and screened to select a -14(1168 microns)/
+65(208 microns~ particle size cut ~Tyler mesh). Ovex-
sized particles were collected and granulated on a
Fitzmill using a 14 mesh screen and low rpm's. This was
screened to select a -20~833 microns)/~48(295 microns)
particle size cut. Both materials were dedusted by
blowing off fines in a fluid bed dryer using ambient
alr .
The admix was prepared at 400 pounds per batch in a
drum mixer. Carbonate, granular STP twith dye sprayed~
on~ brightener, enzymes, and suds supressor prills were
blended with the compacted mainstream product cut and
regranulated overs. The ratio of mainstream product cut
to overs was 7 to 1~ Mineral oil was sprayed on the
final admix in 30 to 40 pound batches at a 1~ level
using a Porberg Mixer.
The composition of Example 1 is preferably incor-
porated into a laminated laundry product form~d from ~wo
plies of water insoluble tissues, at least one of which
is water permeable, which are ~aminated together. At
least one of the plies has cup li~e depressions, sur-
rounded by rims and the other ply being attached to the
first ply at the rim to physically separate the cups.
In one embodiment the laminate is made with plies of the
~ 27~
- 13 -
tissue paper described by Trokhan in U.S. Patent
4,529,480, issued July 16, 7985. The tissue had good air
permeabilit~ as set Eorth in U.S. Patent 4,170,565,
Flesher et al, issued October 9, 1979. There are 12 cups,
having about 20 cc capacity each and at least 8 of the
cups are Eilled with about 9 gm (11 cc) of the detergent
composition and the other cups are filled with at least
one detergent adjuvant. Other materials which can be use~
to form suitable laminates and processes for forming
suitable laminates are disclosed in U.S. Patent No.
4,638,907, issued January 27, 1987.
When the composition of Exa~ple 1 is incorporated itl
said laminated laundry product, it exhibits superior
solubil1ty.
Example II
The ~ollowing granular detergent composition can be
prepared and used according to Example 1.
ase Granules
Grams Final Composi-
~ t~on per_use
Sodium C13 linear alkyL-
benzene sulfonate 15.?5 6.81
Sodium C14_15 alkyl sulate 15.75 6.81
Sodium silicate ~1.6 ratio) 7.88 3.41
Sodium sulfate 23.01 9.95
Polyethylene glycol
(m. wt. 8000) a . 7~ 0.34
Sodium polyacrylate
Im. wt. 45~0) 1.05 0.46
C12 13 alcohol poly-
ethoxylate ~6) 1.57 0.68
Sodium citrate 32.15 13.90
Unreacted 0.35 0.15
Moisture 1.7 - ?3
43.23
- 14 -
Preblend
Base granules 43.23
Sodium aluminosilicate
(hydrated Zeolite A, avg. dia 3 microns) lA.90
Sodium carbonate 3.00
61.13
Admix
Preblend 61.13
~rishtener 0.53
Suds suppressor prill comprising
dimethylsilicone, silica, sodium
tripolyphosphate and polyethylene
glycol IMW = 8000) 0.91
Protease . 1.00
63.57
WHAT IS CLAIMED IS:
