Note: Descriptions are shown in the official language in which they were submitted.
3~2~76~
NON-CAKING BLEACHING DETERGENT COMPOSITION CONTAJNING
A LOWER HYDRATE OF SODIUM PERBORATE
This invention relates to bleaching detergent
compositions. More particularly it relates to non-caking
detergent compositions which contain a lower hydrate of
sodium perborate as the bleaching agent.
Sodium perborate, in the form of its tetrahydrate,
is widely employed in the formulation of bleaching detergent
compositions, some of which also contain nonionic detergents
and builder. When such compositions are added to wash water -
at a higher temperature (near the boiling point), the per-
borate releases oxygen in an active form effecting
bleaching of items being laundered. For laundering opera-
tions conducted at lower temperatures, substantially below
the boiling point of water and sometimes near to room tempe-
rature, the composition may include an activator to facilitate
release o~ active oxygen from the perborate during the
washing operation.
Although perborate-containing detergent compositions
wherein the perborate is present in the form of its usual
hydrate, the tetrahydrate, may be sufficiently flowable when
.j ~.
7~0~311
poured from normal detergent composition containers and
packages, it has been found that when such compositions also
contain nonionic detergent and builder and are held in a
sealed container, which is moisture vapor-tight, at an
elevated temperature for an appreciable time, e.g., a month,
they cakebadly. Thus, detergent compositions containing
nonionic detergent, such as ethylene oxide condensation
products of lipophilic moieties, builder, such as sodium
tripolyphosphate, sodium silicate, sodium carbonate or a
cation-exchanging sodium aluminosilicate (zeolite), or
mlxtures thereof, and sodium perborate tetrahydrate cake
~ objectionably and even after breaking up of the caked com-
; position may still be tacky and flow poorly. Such objec-
tionable characteristics of these compositions are noted
when detergent compositions of the described type are packed
in dispensing bottles which are sealed on storage with a
screw cap or similar closure. In such containers, which
often have hollow handles communicating with the main body
of detergent composition therein, it is more difficult to
break up the caked material, so that it will pour, than it
would be if the material had been packed in the normal or
barrier-type paperboard cartons. The relatively narrow neck,
the substantial rigidity of the bottle, and the presence of
the hollow handle all contribute to the difficulty of
dispensing a caked detergent composition from such bottles,
.. . .
~7~09~ 62301-1307
and their usual transparency makes the consumer more aware
of the objectionable caking. Now, surprisingly, it has been
found that by replacement of the sodium perborate tetra-
hydrate in such detergent composition formulas with a sodium
perborate hydrate in which the degree of hydration is lower,
normally being no higher than that of the monohydrate,
caking may be diminished and even prevented entirely
when the extent of hydration of the sodium perborate
hydrate corresponds to 12 to 15~ of water in the hydrate.
In accordance with the present invention a non-
caking particulat~ bleaching detergent composition comprises
a detersive proportion of synthetic organic nonionic detergent,
a detergency building proportion of a builder for such deter
gent and a bleaching proportion of sodium perborate ~ydrate
of a degree of hydration corresponding to1 to 15% of water in
the hydrate. Such detergent compositions will often contain
from 5 to 28~ of synthetic nonionic detergent, such as
higher fatty alcohol polyethoxylate, lO to 89~ of inorganic
builder, such as sodium tripolyphosphate, sodium silicate,
sodium carbonate, cation-exchanging zeolite or mixtures
thereof, 5 to 50~ of sodium perborate hydrate of up to 15%
moisture content, and l to 15% of moisture (including mois-
ture from the sodium perborate hydrate and any other hydrat-
able salts present). Also within the invention is a detergent
- 4 -
~,,"
~2~6al9~L
composition like that descri,bed, in a sealed and resealable
capped and necked bottle, which composition remains non-
caking after storage for at least four weeks at a tempera-
ture of 43C., and is readily pourable from the bottle upon
opening thereof. Additionally within the invention is a
process which takes advantage of the fact that the sodium
perborate hydrate employed in accordance with this invention
can absorb significant quantities of nonionic detergent,
when that detergent is in liquid state. According to such
la process, at least some of the nonionic detergent is absorbed
in the sodium perborate hydrate during the manufacture of
the present bleaching detergent compositions. Therefore,
more nonionic detergent may be employed in the present
compositions without having a detrimental effect on flow-
ability of the product. Also, because the sodium perboratehydrate utilized in this invention is of greater bleaching
effect than the tetrahydrate, a lesser proportion may be
utilized, leaving room in the formula for other components.
Thus, larger proportions of adjuvants may be used to give the
composition special effects while obtaining its desired
detersive and bleaching properties. ,~
The invention will be readily understood from this
specification, taken in conjunction with the drawing in
which:
FIG. 1 is a vertical elevational view of a packaged
~'
~27~
bleaching detergent composition of this invention being
poured from its container after storage at elevated tempe-
rature;
FIG. 2 is a side elevational view of a "control"
S composition, like that of FIG. 1 except for the employment
of sodium perborate tetrahydrate as the bleaching component,
which cannot be poured from its bottle after being stored at
elevated temperature; and
FIG. 3 is a flow diagram of a process of the
present invention.
In FIG. 1 transparent plastic bottle 11, made
of polymethylmethacrylate, polyvinyl chloride, polyethylene
or of polypropylene is illustrated containing non-ca~ing,
non-tacky, free-flowing bleaching particulate detergent
composition 13 of this invention, seen flowing from threaded
neck 15 of the container to form a stream 17 of detergent
composition particles. It is noted that the detergent
composition particles flow freely through neck 15 despite
the fact that the bottle is being tilted at only a relative-
ly small angle, about 20. Also, it is noted that flow ofthe detergent composition proceeds readily through the
relatively restricted hollow handle portion 19 of the bottle.
Furthermore, it is seen that the composition leaves end wall
21 and bottom 23 free of particles when the detergent com-
position is being dispensed, evidencing the non-tacky nature
~:7~91
of the product. The pouring of the detergent composition
illustrated takes place after cooling of the contents of the
bottle to room temperature, subsequent to storage of the
sealed bottle (sealed air-tight and moisture vapor-tight
with a plastic screw cap, not shown) at a temperature of
43C. for a period of four weeks. After a portion of the
contents was employed forlaundering purposes the bottle was
resealed and subsequently was reopened for further use.
The contents were still non-caking and freely flowing.
In FIG. 2 the bottle 11', identical with that of
FIG. 1, contains a "control" detPrgent composition 25,
exactly like the composition of FIG. 1 except for the inclu-
sion of sodium perborate tetrahydrate in the composition
instead of the sodium perborate hydrate utilized in the
present invention. Such bottle, with the contents thereof
sealed inside, had been subjected to the elevated temper-
ature treatment mentioned for the product shown in FIG. 1,
and composition 25 in the bottle had caked. In some instances
liquefaction of the control composition has been noted. The
contents could not be readily discharged from bottle 11' after
cooling to room temperature, even when the bottle was held
with the discharge opening thereof at the bottom, as illus-
trated. When the bottle was vigorously shaken some material
could be dispensed but the bulk of it remained caked, poorly
flowing and tacky. Note that the particles of the composition
have formed ~ solid mass, the bottom of which is at surface 26,
and that volume 28, below such surface is empty.
~276~9~L
In FIG. 3 base detergent beads, comprising builder,
adjuvants and a relatively small percentage of moisture, are
produced by crutching an aqueous crutcher mix of such
components in crutcher 33 and feeding the crutcher mix to
spray dryer 35, from which the desired base beads are obtained
and fed to blender 37, wherein they are mixed with particles
of sodium perborate hydrate of this invention which have
nonionic detergent absorbed in them. Such perborate -
: nonionic detergent particles are made by feeding nonionic
: 10 detergent, in liquid state, from a nonionic detergent supplytank 27 to spraying and mixing apparatus 29, wherein the
nonlonic detergent is sprayed onto moving surfaces of the
sodium perborate hydrate, which was fed to such apparatus
from bin 31. Various other detergent composition components
lS may also be incorporated in the composition in the spraying
and mixing apparatus 29, the crutcher 33 or the blender 37,
such as perfumes,enzymes, soil release promoting agents,
stabilizers, activators, colorants, fabric softening agents
and flow promoting ingredients. The desired product is
removed from the blender, preferably continuously, through
an outlet represented by line 39, and proceeds to packing,
warehousing and shipping.
The nonionic detergent component of the invented
compositions may be any suitable nonionic detergent of
'~;
~7E;O9~
satisfactory cleaning properties and physical characteristics,
including condensation products of ethylene oxide and propylene
oxide with each other and with hydroxyl-containing bases,
such as alkylphenols, Oxo-type alcohols and higher fatty
alcohols, such as the higher linear alcohols. It is preferred
that the nonionic detergents be such as to be normally solid
at room temperature but to melt at temperatures near to room
temperature, e.g., 45 to 50C., so that they may be in
liquid state when applied to base beads or the sodium
perborate hydrate utilized in conjunction with the present
invention, but may solidify promptly thereafter, although
nonionics which are already liquid at room temperature can
be absorbed as well. Among useful nonionic detergents are the
polyethoxylated alkyl phenols wherein the alkyl is a linear or
near linear alkyl of 7 to 12 carbon atoms, preferably 8 or 9,
and which contain from 3 to 30 moles of ethylene oxide, preferably
3 to 15, e.g., 9 moles thereof per mole of the phenol. The much
preferred nonionic detergents are the condensation products of
from 3 to 20 moles of ethylene oxide with a mole of higher fatty
alcohol, preferably linear alkanol, of lO to 18 or 20 carbon
atoms. Preferably from 6 to 15 moles of ethylene oxide are
present per mole of higher alcohol and more preferably the range
is 6 to 9 or 11. The alcohol will have an average of from 12 to
15 carbon atoms per mole. More preferably, 6, 6.5, 7 or ll moles
of ethylene oxide will be present per mole of higher alcohol of
12 to 15 carbon atoms per mole. Among the useful
~276~9~ 62301-1307
nonionic detergents are those sold under the trademarks
Alfonic~1214-60C by Conoco Division of E.I. Dupont de
Nemours, Inc., and Neodols~ 23-6.5 and 27-7, available from
Shell Chemical Company, or equivalent types.
Mixtures of various nonionic detergents may be
utilized or a single such product may be employed. Also, while
it is preferred that only nonionic detergsnt be employed it is
within the scope of the invention to employ anionic detergent
(s) in conjunction with the nonionic detergent (s), providing
that it does not adversely affect the properties of the com-
position. Among the anionic detergen-ts which may be utilized
are the water soluble higher linear alkyl benzene sulfonates,
e.g., sodium linear dodecylbenzene sulfonate, olefin sul-
fonates, paraffin sulfonates, monoglyceride sulfates higher
fatty alcohol sulfates, e.g., sodium lauryl sulfate, and
highter fatty alcohol polyethoxylate sulfates. In such com-
pounds the high fatty groups will normally be of 8 to 20 carbon
atoms, preferably 10 to 18 and more preferably 12 to 16. The
number of moles of ethylene oxide per mole of detergent will
usually be in the range of 1 to 20, preferably 3 to 10, if
present. Usual]y the proportion of anionic detergent, if pre-
sent, will be less than that of nonionic detergent, sometimes
being from 10 to 50 ~ thereof. While amphoteric and cationic
detergents and surface active agents may also be present, any
contents thereof will normally
-- 10 --
GC)9~1
,
be small. It may sometimes be desirable to utilize yuater~
nary ammonium fabric softening agents, such as the di-lowex
alkyl di-higher alkyl quaternary ammonium halides, e.g.,
dimethyldistearyl ammonium chloride or diethyldipalmityl
ammonium bromide, but such are considered to be adjuvants
rather than detergents.
Various builders and combinations thereof which
are effective to increase the detergency of the nonionic
detergent and the detergent composition and to improve
general washing properties of such composition include both
water soluble and water insoluble builders. Among the water
soluble builders the inorganic salts are preferred but
various organic builders may also sometimes be used, such
as sodium citrate, trisodlum nitrilotriacetate, organic
lS phosphates, gluconates and polyelectrolytes. Among the
water insoluble builders those which are preferred are the
naturally occurring zeolites and zeolite-like materials and
other ion-exchanging insoluble compounds that act as deter-
gent builders. Of the various zeolites, A, X and Y are
preferred with Zeolite 4A being most preferred. Generally,
such zeolite will be of the formula
2)x (A12O3)y~(SiO2)z-W H2O
wherein x is 1, y is from 0.8 to 1.2, z is from 1O5 to 3.5
~;~7~:)9~
and w is from 0 to 9, preferably being 2.5 to 6. Such
zeolites are characterized by having a hiyh ion exchange
capacity for calcium ion, which is normally for about 200 to
4C0 or more milligram equivalents of calcium carbonate
hardness per gram of the aluminosilicate, on an anhydrous
zeolite basis. The zeolite will normally be of a moisture
content in the range of 5 to 30%, preferably 15 to 25~,
e.g., about 20~.
The preferred water soluble inorganic builder
salts employed in accordance with this invention include
polyphosphates, carbonates and silicates, usually as the
alkali metal salts and preferably as the sodium salts.
While pyrophosphates may be present the preferred poly-
phosphate is sodium tripolyphosphate, and normally a hydrated
or water treated form thereof will be utilized. Instead of
sodiwn carbonate, sodium sesquicarbonate can be present
instead or a mixture of sodium carbonate and sodium bicarbonate
may be employed, depending on the product characteristics
desired. The sodium silicate will usually be charged to the
crutcher mix in liquid form but in this specification the
pxoportion thereof given is on an anhydrous basis, which is
also true with respect to the other components (except for
the perborate and any hydrated polyphosphate). The sodium
silicate will usually be of Na2O:SiO2 ratio in the range of
1:1.6 to 3.0, preferably 1:1.6 to 2.4, e.g., 1:2.0, 1:2.4.
~;~76~
Various other suitable builder salts may be employed and
various mixtures thereof may be utilized. However, it is
most preferable that the primary builder salt be sodium
tripolyphosphate and that there also will be present with it
sodium silicate and/or zeolite. In those instances wherein
phosphate is to be avoided because of eutrophication problems,
zeolite(s), mixtures of carbonate and zeolite, carbonate and
bicarbonate, and carbonate, bicarbonate and zeolite, (in such
compositions silicate may also be present~ or other non-
phosphate builder combination may be utilized.
The sodium perborate hydrate employed in accordance
j~ with this invention, is one, the hydration of which corresponds
to considerably less moisture than thàt of the perborate
tetrahydrate. Thus, where sodium perborate tetrahydrate
15 includes about 47% of moisture and about 10.4% of active
oxygen, the monohydrate contains about 18% of moisture and
about 16% of active oxygen. The active oxygen content is
about the same ovex a range of moistures from about 12 to
18% but the lower portions of this range, 12 to 15% or 12 to
14%, e.g., 13%, are found more useful because it is suchthat the non-caking characteristic of the detergent composi-
tion is best maintained and unduly rapid release of oxygen
from the composition in the wash water does not occur, which
has been noted when the perborate of such compositions
included less than 12% of water of hydration. The useful
l3
9~L
perborate hydrates may be made by heating sodium perborate
tetrahydrate to drive off the desired proportion of moisture.
While it is possible to mix perborate hydrates of different
moisture contents to obtain the desired average moisture
such procedure is considered to be inferior to controllably
dehydrating the perborate tetrahydrate to the desired moisture
content, so that the perborate particles are very similar in
moisture contents.
In addition to the three major components (and
water) of the present compositions various adjuvants may
also be present. Among such are soil release promotion
compounds, fabric softeners, enzymes, stabili~ers, activators
for the perborate, anti-gelling and anti-setting agents,
anti-oxidants, colorants, perfumes, fluorescent brighteners,
dispersing agents, sequestrants, flow promoting agents,
fillers, bead strength improvers, anti-foams, bactericides,
fungicides and bead density modifiers.
Preferred soil release promoting compounds are the
copolymers of polyethylene terephthalate and polyoxyethylene
terephthalate of molecular weights in the range of about
15,000 to 50,000, preferably 19,000 to 43,000, more prefer-
ably 19,000 to 25,000, e.g., about 22,000. In such polymers
the polyoxyethylene will be of a molecular weight in the
range of 1,000 to 10,000, preferably 3,000 to 4,000, e.g.,
about 3,400 and the molar ratio of polyethylene terephthalate
/4
6~)9~
to polyoxyethylene terephthalate units will be within the
range of 2:1 to 6:1, preferably 3:1 to 4:1, e.g., about 3:1.
In such copolymers the proportion of ethylene oxide to
phthalic moiety in the polymer will be at least 10:1 and
often will be 20;1 or more, preferably being wlthin the
range of 20:1 to 30:1, e.g., about 22:1. Such materials are
obtainable from Alkaril Chemicals, Inc., under the trademarks
Alkaril QCJ and Alkaril QCF. Other copolymers of this type
but of different molecular weights and proportions of
components may also be used but are not considered to be as
effective. Among the useful fabric softeners, in addition
to the quaternary ammonium halides, previously mentioned,
are soaium bentonites, such as Wyoming or western bentonites,
which often have good gelling and cation exchange capacities
(over 50 milliequivalents of calcium ion per hundred grams).
Enzymes that are useful include proteolytic and amylolytic
enzymes, e.g., Maxatase and Esperase 4T. Such enzymes, as
referred to herein, are commercial preparations which include
a carrier with the active ingredient (weights given herein
are with respect to the preparations, as supplied). Enzyme
stabilizers, including sodium formate and formaldehyde, may
be present, as may be stabilizers for other components of
the composition. Activators for the perborate include N-
acetyl caprolactam and acetamides, and those known as TAED,
TAGU and PAG, as well as other chemicals containing active
i 5
~1~76~9~1
acetyl groups that can produce peracetic acid._ ~mong the
anti-gelling and anti-setting agents may be mentioned citric
acid, sodium citrate and magnesium sulfate, the citric
materials normally being employed in small adjuvant quanti-
ties rather than in larger builder proportions. Antioxidants,colorants, perfumes, bactericides and fungicides are well
known in the art and are minor components of the invented
products,so they will not be discussed further. Fluorescent
brighteners are usually of the stilbene type, such as Tinopal
CBS-X and Tinopal 5BM. Among useful dispersing agents are
the polyacrylates, which also contribute to bead strength
and allow control of bead density. Sequestrants, such as
NTA, EDTA and citric materials (in small proportions) may be
present. Among the flow promoting agents magnesium silicates
are preferred. There is normally little room in the present
formula for fillers but a useful filler, which is also a crutcher
mix improving agent, is sodium sulfate and sometimes it
is possible to include this in the formula because of the
"hole" left by replacement of a larger proportion of sodium
perborate tetrahydrate with a smaller proportion of the lower
hydrate. Among useful anti-foams are the well known dimethyl
silicones and soaps, such as sodium tallow soaps, sodium
hydrogenated tallow soaps and sodium stearate. In larger
proportions such soaps may be employed for their detergent
contribution too, in substitution for anionic detergent,
when such was present in these compositions.
~r~ 1 b
~7~)9~
While in the broadest sense of the pr~sent invention
proportions are not critical, there are certain proportions
which are highly desirable for best functioning of the
invention. Thus, the content of synthetic nonionic organic
S detergent will usually be within the range of 5 to 28% of
the composltion. Below 5% insufficient detersive activity
is noted and it appears that about 28~ is the upper limit of
nonionic detergent content in the present product without
resulting in tackiness and a susceptibillty to caking
of the product. Preferably, especially when the synthetic
nonionic detergent is an ethylene oxide condensation product
of a higher fatty alcohol or an alkyl phenol, and no other
detergent is present, the proportion thereof will be from
10 to 25%, more preferably 14 to 22% and most preferably
about 18 to 20%. The proportion of inorganic builder is
normally in the range of 10 to 89~, preferably being 30 to
55% and most preferably being from 35 to 50%, e.g., 39%
and 45%. For those compositions containing sodium tripoly-
phosphate as the principal builder the proportion thereof
will usually be from 30 to 55%, preferably 35 to 50%, e.g.,
37% and 43~ Normally sodium silicate is present with the
polyphosphate and the proportion thereof will be from 1 to
10%, preferably 1 to 8% and more preferably 2 to 4%, e.g.,
about 2 or 3~. However, in some instances larger proportions
of silicate may be employed, usually when instead of~
~2~6~ 62301-1307
polyphosphate being present, in non-phosphate formulas,
zeolite, carbonate and/or bicarbonate are present instead. In
such instances the silicate content may be from 2 to 10%, pre-
ferably 3 to 5%. The contents of carbonate, bicarbonate and
zeolite vary according to the formulas. When zeolite is
utilized with tripolyphosphate it will normally be present in a
proportion about 1/5 to 1/2 that of the tripolyphosphate but up
to an equal proportion of zeolite may sometimes be used. In
non-phosphate compositions the percentages of zeolite will
normally be from 5 to 25%, preferably 10 to 20%. Proportions
of carbonate in non-phosphate compositions may be from 5 to
30%, preferably 10 to 25%, as may be the proportions of
bicarbonate.
The sodium perborate hydrate component oE this in-
vention will generally be within the range of 5 to 50% of the
composition, preferably 10 to 30~ and more preferably from 15
to 25% thereof. When nonionic detergent is absorbed by the
perborate hydrate photomicrographs show that that it fills in
roughnesses on the surfaces of the perborate particles, result-
ing in a substantially smooth surfaced bead which flo~s betterthan do roughened particles of the same composition. While
below 12~ moisture content the hydrate may too readily release
oxygen in -the wash water, in some instances such quick release
may be desirable and therefore the moisture content may be as
low as 1~ and the range of
18 -
... .
7~
such contents may be from 1 to 15% or 1 to 1~%. The lower
moisture content hydrates within such range may be more
absorptive of nonionic detergent than those of higher moisture.
The proportion of moisture in the present compositions
will normally be in the range of 1 to 15%, although it is
contemplated that in the presence of certain fomponents,
such as zeolite and/or bentonite, a higherRmoisture content
limit may apply, e.g., 18%. Such moisture includes moisture
in the sodium perborate hydrate and includes other readily
removable moisture from other hydrates which may also be
present. A preferred moisture range is 5 to 15% and more
preferred is 10 to 13 or 14%. Adjuvants that are present
are desirably limited to from 1 to 15%, with individual
adjuvants normally being present in a proportion not greater
than 10%, e.g., 0.1 to 8%. Of course, the proportions of
ad~uvants depend on their nature and function so ranges for
only a few components will be given here. Normally, the
proportion of soil release promotion compound will be from 1
to 10~, preferably 3 to 8~, which range is also suitable for
a fabric softening agent, such as bentonite. Quaternary
a~monium halide fabric softeners may be present in a propor-
tion from 0.5 to ~% and enzymes normally constitute from 0.2
to 2~. Activators for the perborate may be from 0.1 to 4%
and anti-gelling and anti-setting agents may be from 0.2 to
3%. Perfumes and colorants will normally constitute from
~ 19 --
~L276()9~L
0.1 to 1% and flow promoting agents may be from 0.5 to 5%.
Anti-redeposition agents, such as CMC, may be from 0.5 to
3%, and polyacrylates may be ~rom 0.05 to 1~. Fillers, such
as sodium sulfate, which also serves to improve particle
properties and flow while desirably affecting mix of the
crutcher slurry when it contains sodium tripolyphosphate,
may be from 0.5 to 8 or 10%.
In an important embodiment of this invention the
described compositions are packed in hermetically sealed
bottles, which resemble blow-molded bottles that are conven-
tionally used to hold liquid detergents. However, the
present bottles are very preferably clear, so that the
attractive particles of the product may be seen by the user.
Often the detergent composition particles are colored,
sometimes multicolored, and it is desirable to be able to
see them. One may also note how theproduct flows and one can
see that it does not adhere to container walls. Materials
for the container have previously been described and the
present discussion will be limited to disclosures of some of
the salient features of the bottles and their dimensions.
The bottles can fairly be characterizea as narrow necked,
relatively speaking, with the neck generally being round and
of an open cross-sectional area in the range of 2 to 40 sq.
cm. ~he hollow handle has a cross-sectional area for the
opening therein in the range of 1 to 10 sq. cm.
- 20 -
~27~ 9'1
The compositions of this invention are free-flowing, often
flowing through a suitable restricted orifice at a rate about
70~ or more that of dry sand. At the least the flow rate
is comparable to those of other free-flowingdetergent powders.
Thus, the bottles are readily filled by automatic filling
equipment and the particles of detergent composition easily
fill the hollow handle portion. Of course, bottles without
such handles, and containing the invented compositions, are
also within the product aspect of this invention. After the
heat storage test previously described, and after cooling,
the invented compositions readily flow through the handle
and out the bottle when such is tilted only slightly, and
flow at a rate approximating the initia~ flow rate. Similarly,
the pr~duct flows readily, does not cake and is not tacky after
the bottle is recapped, is stored again at elevated temperature,
is opened and is placed in pouring position, as illustrated
in FIG. 1 of the drawing.
The manufacture of the invented compositions is
essentially straightforward and does not require the use of
equipment not normally employed in the detergent industry.
O~ course, there are different ways that the perborate
hydrate may be combined with the constituents of the bleach-
ing detergent composition. It may be blended with the other
individual components, with the dry powders being mixed and with
the liquid components being sprayed or dripped onto the
- 21 -
~27~09~
surfaces of the moving powders. This is not preferable
because it is desirable to have the composition in non-
dusting form, such as in beads of the type obtained from
spray drying operations. Because sodium perborate decomposes
at elevated temperatures, such as those that obtain in a
spray drying tower (200 to 500C.~ the perborate will not be
included in the crutcher mix and will be post-added to any
materials that are spray dried. However, the perborate
hydrate of this invention may be mixed with spray dried base
beads containing all or almost all of the other components
of the detergent composition and then have nonionic deter-
gent applied to the mixture in a tumbling drum, fluidized
bed, coating pan, V-blender, zig-zag blender or similar
e~uipment.
Preferably, the perborate hydrate will be "loaded"
with nonionic detergent in li~uid state at elevated tempera-
ture, usually in the range of 50 to 65C., e.g., 55C.,
60C., with the load being to the extent of 20 to 30%
nonionic, and this product, at room temperature, will be
mixed with room temperature base beads to which the desired
additional proportion of nonionic detergent, if any, has
previously been added~ It has been found that as much as
30~ of nonionic detergent may satisfactorily be absorbed
into the perborate hydrate particle and, as previously
discussed, the solidified detergent covers pits on the
surfaces of the particles, making it more readily free
- 22 -
~L27~9~
flowing . Better absorption is obtainable when the moisture
content of the perboxate hydrate is less than the theoretical
amount of about 18%, with the range of 12 to 15% being
preferred, especially 12 to 14%, and with 13% being most
preferred. In another embodiment of the invention the
perborate hydrate may have nonionic detergent absorbed into
it and separately spray dried particles of sodium tripoly-
phosphate, either hydrated or anhydrous, may similarly have
nonionic detergent absorbed by them, although the limit of
absorption is about 20~ for the tripolyphosphate, and a
reasonable range of nonionic detergent contents ofsuch
product is about 5 to 20%. Then, these two components may
be mixed with the various other components of the composi-
tion, which may be in agglomerated form so as to improve the
particle sizes thereof, with all or substantially all the
particles desirably being in the range of 8 to 140 mesh
(over 90% and preferably over 95% by weight of the particles
being in such range). If more than the allowable limit of
particles is outside such range, screening is employed to
re~ove them. For purchased materials specifications will be
set SQ that the particles will be in the desired siæe range.
The mesh sizes given above correspond to U.S. Sieve Series
screen numbers.
The advantages of the invention have already been
referred to. Primarily, a caking problem which could
y - 23 -
Z:7 EiO9~
seriously interfere with marketing of bleaching nonionic
detergent compositions in sealed bottles has been overcome.
By replacement of sodium perborate tetrahydrate with the
lower hydrates, in accordance with this invention, stability
of the product against such caking and prevention of the
development of poor flow properties and tackiness are
achieved. In addition, because the perborate lower hydrate
absorbs more nonionic detergent, larger quantities of such
detergent may be included in the composition without causing
caking, poor flow and tackiness. Because ~he lower perborate
hydrate includes about 50% more active oxygen than the
perborate tetrahydrate less can be used and other components
can be incorporated in the product to further improve its
characteristics. Thus, the final result is an improved and
1~ stable product which has the desired bleaching properties of
the corresponding compositions based on sodium perborate
tetrahydrate and is of excellent detergency, equal to that
of the perborate tetrahydrate compositions, while being non-
caking, free-flowing, non-tacky, more absorptive of nonionic
detergent and better able to provide flexibility o formula-
tion, due to the "hole" left in the formula by elimination
of the water of hydration of the tetrahydrate.
The following examples illustrate but do not limit
the invention. Unless otherwise indicated all parts are by
weight and all temperatures are in C.
- 2~ -
~2~609~
EXAMPLE 1
-
Component Parts
Waterl 54-3
Sodium silicate (Na2O:SiO2 = 1:2.0) 6.8
5 Sodium tripolyphosphate (hexahydrate)3 42.7
Sodium carboxymethyl cellulose (detergent grade) 1.5
Magnesium silicate (flow improver) 0.5
Fluorescent brighteners4 0-3
Colorant ~blue dye and pigment) 0-04
106.14
1. City water of less than 150 p.p.m. hardness as (CaCO3)
or deionized water
2. 44.1% aqueous solution
3. Other hydrated STPP may be substituted
4. Mixtures of 0.24 part of stilbene brightener No. 4
(Colgate-Palmolive Co. designation) and 0.06 part
Tinopal CBS-X
A crutcher mix of the above formula is made by
adding the vaxious components to the water thereof, which is
charged to a standard detergent crutcher, and the mix is
heated to a temperature of about 50C. It is then spray
dried in a conventional countercurrent spray tower with the
tower temperature being about 350C. During drying enough
water is removed from the product so that its final moisture
content is about 16~. The spray dried beads obtained are
free-flowing particles substantially all of which are within
the range of 8 to 140 mesh, with over 75~ of the particles
~L27~;~9~L
being within the range of 20 to 80 mesh.
To 56.9 parts of the spray dried beads there are
added 17 parts of sodium perborate hydrate which has a
moisture content of about 13~, 1 part of a phosphoric acid
ester of a mixture of approximately equal parts of cetyl and
stearyl alcohols, and 0.8 part of enzyme ~Esperase 4.0 T).
To this mixture there are added 16 parts of a condensation
product of ethylene oxide and higher fatty alcohol (7 moles
of ethylene oxide per mole of higher linear fatty alcohol of
12 to 15 carbon atoms) which is at a temperature of about
60C., and the addition is by spraying or dripping the
nonionic onto the tumbling particles of the other components.
The composition is mixed until the fatty alcohol is satisfac-
torily distributed over the various particles and is absorbed
lS by them. During mixing 0.4 part of perfume is added. When
mixing is complete, which takes about ten minutes, the
product is removed from the mixer (screened, in some instances)
and is filled into clear polyacrylate bottles having hollow
handles and relatively narrow necks, which bottles are then
sealed, cartoned, warehoused and shipped.
The bleaching detergent composition made is of
particles within the size range previously given for the
spray dried components (the perborate starting material was
also of such a size). It is of a density of 0.7 g./cc., and
is free flowing. The product contains about 17% of the
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~2~6~9~
nonionic detergent, 46~ of sodium tripolyphosphate, 17% of
the sodium perborate hydrate, 3~ of sodium silicate, 1~ of
phosphoric ester, 1% of sodium carboxymethyl cellulose, 0.9%
of enzyme, 0.5% of flow promoter, 0.4% of perfume, correspond-
ing minor percentages of the other adjuvants and about 13of moisture ~including that in any hydrates from which it
is removable at 105C.).
When the hermetically sealed container of the
bleaching detergent composition of this invention is subjected
to a stability test, by being kept at a temperature of 43C.
for a period of four weeks, the product passes the test. In
such test the bottle and contents are allowed to cool down
to room temperature before the bottle is opened and then the
contents are poured out of the bottle. It is noted that
they pour relatively easily, do not cake and do not adhere
to the walls of the bottle. By a standard test employed to
measure flow rate they flow through a restricted orifice at
a rate about 70% of that of dry sand. Even when the heated
materials are poured from the open bottle while still warm,
they flow well. Chemical analyses show that the active
oxygen content of the perborate has not diminished during
storage and also the P2O5 content of the polyphosphate has
not been decreased. The product is an attractive free-
flowing detergent composition which can satisfactorily
withstand elevated temperatures likely to be encountered
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~Z~76~9~
durin~ normal warehousing, shipping and storage before use.
When tested in laboratory, commercial and home washing
machines wherein washing is conducted at elevated tempera-
ture, e.g., 75-90C., the composition is found to have
excellent washing and bleaching properties against normal
laundry soils and against various stains. Such properties
are retained during the normal use of the product, which
involves repeated openings and closings of the polyacrylate
bottle, and the product remains non-caking, non-tacky and
readily flowable during such repeated uses.
When 13% moisture sodium perborate hydrate is
replaced by other such hydrates, such as those of moisture
contents of 12, 14 and 15~, essentially the same results
obtain and the product is non-caking on elevated temperature
storage in sealed containers. Similar results are obtain-
able when instead of the sodium tripolyphosphate a mixture
of approximately equal parts of sodium carbonate and sodium
bicarbonate is substituted or when half of the tripoly-
phosphate is substituted by hydrated Zeolite 4A (20% water
of hydration). However, the flowability of the non-phosphate
product is not as good as that of the primary product of
this example.
Results like those of the primary example herein
are also obtainable when no flow improver is employed,
but flow rates will be somewhat diminished. Similarly,`when
- 28 -
~2'7~911
the only components are the perborate hydrate, tripolyphosphate,
nonionic detergent and sodium silicate, in the proportions
shown in this example, an excellent detergent is obtained
but the various desirable properties of the adjuvants are
wanting.
~ hen the 17 parts of the perborate hydrate of this
example are replaced by sufficient sodium perborate tetra-
hydrate to have the same active oxygen content and the
product resulting is heat tested by the method pxeviously
described herein such product is found to cake badly and in
some instances liquid may be observed among the particles of
this "control" composition. Thus, it is consldered that the
control composition is unacceptable for commercial use in
sealed containers, like the bottles that have been mentioned.
It is also considered that the control is unacceptable for
use in barrier cartons which are moisture-tight.
EXAMPLE 2
Sodium perborate tetrahydrate particles of sizes
in the 8 to 1~0 mesh range are partially dehydrated, to
moisture contents in the range of 12 to 15~ by controlled
heating, as by fluidized bed heating or by passing them
through a heated pipe at a controlled flow rate. During
such heating operations the particles swell slightly but at
the conclusion of it they are within the desired size range
~ - 29 -
jO9~
(8 to 140 mesh) and of desirable density (about ~.~ or
0.6 g./cc.) so that the final product may have a ~ensity of
about 0.7 g./cc. Particles so made are employed as sorbents
for nonionic detergent t as described herein.
A nonionic detergent like that descri~e~ in Example
1 is heated to 60C. and is coated onto and absG~ed in the
perborate hydrate particles by being sprayed on~ such
?articles while they are kept in motion in a pan granulator
or coater. Instead of the described equipment *here may be
employed various other types of mixers, including inclined
drums, Day mixers and V- and zig-zag blenders. Mixing
may be continuous or batch. The type of blender or mixer
employed is one which will not tend to cause disintegration
or agglomeration of the particles. It is found that the
nonionic detergent - perborate hydrate particles obtained
are free flowing, of the desired particle size (8 to 140
mesh) and smoother in appearance than the perborate particles
were initially. When the moisture content of the perborate
is less than 12% and such experiment is repeated good
nonionic absorption is also obtainable but when the moisture
content is higher than about 18% sorption is much diminished.
For example, sodium perborate tetrahydrate is not a good
absorber for nonionic detergent.
The sodium perborate hydrate, containing about 30%
of nonionic detergent ~total basis), is mixed with spray
- 30 -
~76~
dried detergent base beads liXe those of Example 1 a~ter
such base beads have been mixed with the balance of the
formula, except perfume, with allowance being made in the
formula for the nonionic detergent previously mixed with the
perborate. Subsequently perfume is mixed in and after five
or more minutes mixing at room temperature the product is
ready for packaging, which is effected in the manner described
in Example 1~
The product made is of the same composition as
lQ that of Example 1 but because of preliminary absorption of
nonionic detergent by the perborate hydrate particles the
absorption of the balance of the nonionic detergent during
manufacture proceeds more readily. The product of this
example is resistant to decomposition and deterioration at
elevated temperatures by the test method previously described.
It is non-caking and free flowing after such test and is an
excellent bleaching detergent.
In variations of this example the percentage of
perborate hydrate is increased to 25% in the final product,
with the other components being correspondingly decreased.
A product of greater bleaching effectiveness is obtained
than when 25~ of sodium perborate monohydrate is employed in
the same type of formula. Also, the active oxygen and P2O5
contents of the product are substantially retained, whereas
those of the "control", containing perborate tetrahydrate,
~27~9~
are decreased after storage at elevated temperature.
In another variation of this example the perborate
of this inventionS containing nonionic detergent, may be
mixed with the spray dried base beads, followed by mixing
S with other components, including the balance of nonionic
detergent. The resulting product is a satisfactory bleaching
detergent and withstands the elevated temperature test well. In
a further variation the nonionic detergent is absorbed
separately by the base beads and perborate hydrate parts of
the composition and then such are mixed together. The
proportions of nonionic employed in each absorption step
will be the maximum absorbable proportion for absorption by
the perborate hydrate, with the balance of nonionic being
absorbed by the base beads (principally by the sodium tripoly-
phosphate). The product will resist elevated temperaturestorage in sealed bottles without caking. A further modifi-
cation of the descrihed techniques is to dry mix the various
components of the composition,after having first absorbed
nonionic detergent onto the perborate hydrate particles and
the sodium tripol~phosphate particles. However, dry mixes
are not generally preferred and if they are made,certain
liquids, such as perfumes and sodium silicate solution,
will still have to be mixed in and satisfactorily distributed
throughout the composition.
- 32 -
~27~9~ 62301-1307
EXAMPLE 3
A composition comprising 18% of nonionic detergent
(about equal parts of ethoxylated fatty alcohols of 16 to 18
carbon atoms and 3 and 12 moles of ethylene oxide per mole of
fatty alcohol),35~ of sodium tripolyphosphate, 11~ of hydrated
Zeolite 4A (20~ water content), 8~ of sodium silicate of
Na2O:SiO2 ratio of about 1:2, 6% o sodium perborate hydrate
(14% moisture), 3~ of tetraacetylethylenediamine (TAED perbo-
rate activator), 1% of sodium carboxymethyl cellulose, 0.2~ of
stilbene fluorescent brightener, 2% of sodium formate, 1~ of
proteolytic enzyme, 14% of moisture and the balance of minor
adjuvants, is made by -the principal method of Example 2 and
satisfactorily passes the heat storage test previously des-
cribed. When instead of the lower hydrate of the perborate,
the tetrahydrate is employed the product cakes badly This
example illustrates that instead of employing larger propor-
tions of perborate, smaller proportions may be utilized,
together with a perborate activator, such as TAED. The
products made according to this example, when tested at lower
washing temperatures, such as 40 to 50C., are good detergents
and effectively bleach stains because of the release by the
perborate of active oxygen in the presence of the activator.
Similar results are obtainable when the compositions
of this example are made by the other techniques
. - 33
-: ~Z7~iO~
described in the previous example and elsewhere in the
specification.
EXAMPLE ~
The principal formula of Example 1 is modified by
adding to it any of the following components: 5% of the soil
release promoting copolymer of polyethylene terephthalate
and polyoxyethylene terephthalate; 8% of fabric softening
bentonite; 1~ of dimethyldistearyl ammonium chloride; 1% of
polyvinyl pyrrolidone; and/or 0.1% of dimethyl silicone.
Such components may be added to the crutcher mix or are post-
added after production of the base bead, as befits their
stabilities. The proportions of the other components may be
decreased accordinglyO One or more of the five additional
components mentioned may be utilized in the basic formula
and the basic formula may be varied too. For example,
instead of the condensation product of ethylene oxide with
higher fatty alcohol the nonionic detergent may be a conden-
sation product of ethylene oxide with isooctyl phenol or
nonyl phenol, of the type previously described, or may be
a different fatty alcohol ethoxylate or mixture thereof with-
in the specification description. The enzymes employed may
be either amylolytic or proteolytic or a mixture of both.
The polyvinyl pyrrolidone may be used with the CMC or partial-
ly in replacement thereof. While the soil release promoting
copolymer described in the specification is preferably
- 34 -
7~ [)9~
employed, other such materials may also be used.
The products of this example will be good bleaching
detergents under the appropriate conditions of use and will
be non-caking on storage at elevated temperature in hermetical-
ly sealed containers~
In addition to the modifications mentioned above,
the various proportions of components of the principal
formulas of the examples may be varied so that they are +10
and +25~, providing that they are still within the scope of
the invention, as described, and the products made will be
good bleaching detergents of good elevated temperature
storage characteristics.
This invention has been described with respect to
~arious examples and illustrations thereof but is not to be
limited to these because equivalents and substitutes may be
employed without departing from the invention.
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.
