Note: Descriptions are shown in the official language in which they were submitted.
C 7197 OR)
GRANULATED BLEACH ACTIVATOR PARTICLES
Technical field
This invention relates to bleach activator granules,
method of making such granules and use thereof in
bleaching and/or detergent compositions. More
particularly it relates to improved bleach activator
particles prepared by spray-drying for use in or with a
detergent and/or bleach composition.
Backqround and prior art
It is well known that peroxide compounds, such as
perborates, percarbonates, perphosphates and
persilicates, are highly useful for chemical bleaching
of stains found on both coloured and white fabrics, and
are thus also useful as bleaching agents for
incorporation in laundry detergent compositions. Said
peroxide compounds are most effective at high wash
temperatures, i.e. at or near the boil wash temperature,
.
but are substantially ineffective at lower temperatures
of e.g. below 60~C. Many substances are known in the art
which are referred to as bleach activators rendering
peroxide compound bleaches effective at bleach solution
temperatures of below 60C, by forming an organic
peroxyacid in situ. A bleach activator can thus
generally be described as an organic peroxyacid bleach
precursor which in the bleaching solution reacts with
the inorganic or organic peroxide compound, thereby
releasing the corresponding peroxyacid.
Many such bleach activators are known in the art, most
ox which contain perhydrolysable N-acyl or O-acyl
; residues. Examples of these include both the water-
insoluble compounds such as succinic, benzoic and
phthalic anhydrides, N,N,N',N'-tetraacetyl-ethylene
C 7197 (R)
diamine (TAED) and tetraacetyl-glycoluril (TAGU), as
well as the water-soluble compounds such as acetyl
salicylic acid, glucose penta-acetate (GPA), and the
various esters of phenols and substituted phenols, e.g.
sodium acetoxy benzene sulphonate (SABS), sodium
benzoyloxy benzene sulphonate (SBOBS) and sodium
nonanoyloxy benzene sulphonate (SNOBS).
Hydrolytic instability requires that these bleach
activators be protected from the surrounding media, e.g.
when incorporated in detergent compositions,
particularly from moisture and alkaline ingredients. On
the other hand, any proper method ox protecting the
bleach activator from chemical attack must still allow a
relatively quick release or dissolution of the activator
in the wash liquor so as to enable the beneficial
reaction with the peroxide compound to occur without
undue delay The most common way of protecting bleach
activators is by methods wherein the powdered bleach
activator material is presented in the form of
agglomerated, granulated and/or coated particles Spray-
drying is another route which has been proposed to
convert bleach activators into a useful particulate
product form.
It is known to prepare granules of water-insoluble
bleach activators, e.g. TAED, TAGU, by spray-drying an
aqueous slurry comprising said water-insoluble bleach
activator (see US Patent 4,4S7,858). It is also known to
incorporate water-insoluble bleach activators in a
detergent slurry for spray-drying (see GB-A-l 540 832),
whereby the resulting granular detergent composition
comprises the bleach activator homogeneously distributed
therein.
It is further known in the art to prepare granules
comprising water-soluble bleach activators by spray-
C 7197 (R)
drying. GB-A-963 135 and US Patent 4,681,695 describe
granules of water-soluble bleach activators prepared by
spray-drying an aqueous slurry comprising said water-
soluble bleach activator and an inorganic (hydratable)
salt, e.g. disodium dihydrogen pyrophosphate. Contrary
to the granules prepared from water-insoluble bleach
activators, the spray-dried granules of water-soluble
bleach activators as disclosed in the process of the
art contain relatively high proportions of diluent
and/or stabilising salts and a relatively low level of
the reactive peroxyacid bleach precursor material. This
level is normally up to about 50% by weight and, for
stability reasons, preferably lower. Nevertheless, the
chemical and physical stabilities of such granules of
the art are in many cases still far from ideal.
Normally, these spray-dried granules suffer from poor
attrition resistance, resulting in breakdown to fines
upon handling, whereby chemical stability is affected.
DescriPtion of the invention
It has now been found that water-soluble bleach
activators can be successfully formed into spray-dried
granules with high bleach activator contents of
satisfactory stability if the water-soluble bleach
activator is spray-dried from a crutcher slurry mix
comprising said bleach activator and a film-forming
polymeric material. Preferably an acidic film-forming
polymeric material is used.
; 30
The present invention therefore provides a stable bleach
activator composition in the form of spray-dried
granules of a water-soluble bleach activator, comprising
in homogeneous distribution:
(it from 50% to about 98% by weight of a water-soluble
` peroxyacid bleach precursor material;
(ii) from 2% to about 50% by weight of a film-forming
C 7197 (R)
polymeric material; and
(iii) from 0% to about 48% by weight of an inert organic
or inorganic salt.
Preferred spray-dried granule compositions will
comprise:
(i) from 60% to about 90% by weight of said water-
soluble peroxyacid bleach precursor;
(ii) from 5% to about 30% by weight of said film-
forming polymeric material; and
(iii) from 5% to about 35% by weight of said inert
organic or inorganic salt.
In another aspect the invention provides a process for
preparing bleach activator granules by spray-drying an
aqueous slurry comprising a water-soluble bleach
activator, wherein said aqueous slurry comprises from
about 30-50% by weight of water, from about 25-69% by
weight of a water-soluble peroxyacid bleach precursor,
from about 1-10.5% by weight of a film-forming polymeric
material, and from 0 to about 44% by weight of an inert
organic or inorganic salt.
:,
The water-soluble bleach activators used in the present
invention are those materials which are soluble in water
to an extent of at least 1% by weight, preferably at
least about 5% by weight, at a temperature of 25C and
pH 7.
Preferred water-soluble bleach activators are peroxyacid
bleach precursors having the general formula I:
: : O
R - C - L (I)
wherein R is an optionally substituted alkyl group
~33~
C 7197 (R)
containing 1-12 carbon atoms or an optionally
substituted phenyl group containing 6-10 carbon atoms,
and L is a leaving group containing an anionic moiety,
the conjugate acid of the leaving group having a PKa in
the range of from 6 to 13.
The alkyl group R can be either linear or branched and,
in preferred embodiments, it is unsubstituted and
contains either 1 or 7-9 carbon atoms. In another group
of suitable bleach activators, the alkyl group R is
substituted and has the general formula II:
R1 - C (II)
R2
wherein R1 is a straight or branched chain alkyl
containing from 4 to 10, preferably 6 to 10, more
preferably 6 to 8 carbon atoms, R2 is H, CH3, C2H5 or
C3H7 and X is halogen (Cl or Br), -OCH3 or OC2H5.
Particularly preferred bleach activators are those in
: which R has the general formula III:
(III)
wherein X is H, a halogen (Cl, Br or F) or a straight or
branched chain alkyl group containing from 1-4 carbon
atoms, expecialiy wherein X is H.
I`
: L can be essentially any suitable leaving group
containing a moiety which is anionic at pH 7. A leaving
group is any group that is displaced from the bleach
activator as a consequence of the nucleophilic attack on
the bleach activator by the perhydroxide anion.
Generally, for a group to be a suitable leaving group it
C 7197 (R)
must exert an electron-attracting effect. Leaving groups
that exhibit such behaviour are those in which their
conjugate acid has a PKa in the range of from 6 to 13,
preferably from 7 to 11 and most preferably from 8 to
11. Also, in order for the activator to have the desired
level of solubility in wash water it is essential that
the leaving group contain an anionic moiety. Non-
limiting examples of suitable anionic moieties are
-S03M, -COOM and -OS03M wherein M is a proton or a
compatible cation.
Preferred bleach activators are those of the general
formula I wherein L is selected from
15 (a) (C~2)XY
Z and
(b) O
- N - C - R3
CH2
wherein Z is H, R3 or halogen, R3 is an alkyl group
having from 1 to 4 carbon atoms, x is O or an integer of
from 1 to 4 and Y is selected from S03M, OS03M and C02M
and wherein M is H, alkali metal, alkalina earth metal,
ammonium or substituted ammonium.
The preferred leaving group L has the formula (a) in
which Z is I, x is O and Y is sulphonate or carboxylate.
A highly preferred bleach activator is sodium p-
35 benzoyloxy benzene sulphonate (SBOBS).
C 7197 (R)
The film-forming polymeric material should preferably be
non-oxidiæable. Such suitable film-forming materials
are, for example, the non-oxidizable polymers, which can
be in the acid form or in the form of their alkali metal
salts. Acidic polymers are preferred.
Acidic polymers usable in this invention can be any non-
cellulosic homo- or copolymeric mono- and polycarboxylic
acids having an average molecular weight of from 500 to
about 1,000,000, preferably from 2,000 to 250,000, more
preferably from 10,000 to 50,000.
Suitable polymers include those derived from acrylic
acid, methacrylic acid, maleic acid, citraconic acid,
aconitic acid, fumaric acid, mesaconic acid, phenyl
maleic acid, benzyl maleic acid, itaconic acid,
methylene malonic acid, alpha-Cl-C4 alkyl acrylic acid,
alpha-hydroxy acrylic acid and acetalcarboxylic acid
monomers, or from the anhydrides of the above monomers
where these exist. The polymers can be homopolymers of
the above mono- or polycarboxylic monomers; or
copolymers af two or more of the above mono- or
polycarboxyl monomers; or copolymers of one or more of
; the above carboxyl monomers with an unsaturated
polymerizable monomer other than the specified mono- and
polycarboxyl monomers; or modified homo- or copolymers
of the above classes having, for example, a non-
oxidizable phosphinic acid or sulphinic acid group.
Preferred acidic, polymeric materials are the
polyacrylic acids, phosphinate-modified polyacrylic
acids, such as described in GB patents 1,~85,235 and
l,595,688 and EP-A-0182411; copolymers of maleic acid
(anhydride) and acrylic or ]methacrylic acid; and acidic
copolymers containing hydrophobic groups, such as
copolymers based on polymethacrylic acid and polyacrylic
acid esters in which the ratio of free carboxyl groups
~3~
C 7197 (R)
to ester groups is at least 1:1. Commercially available
polyacrylic acid polymers are, for example, the products
sold under the trade name "Versicol", supplied by Allied
Colloids, e.g~ Versicol E7 and Versicol E9.
As explained hereinbefore, the aqueous slurry prior to
spray drying to form the bleach activator granules may
or may not contain an inert inorganic or organic salt. A
preferred inert salt is an inert inorganic salt.
Suitable inorganic salts include disodium dihydrogen
pyrophosphate, sodium dihydrogen orthophosphate, sodium
sulphate, sodium bisulphate, magnesium sulphate and
mixtures thereof. A particularly preferred inert salt
usable in this invention is sodium sulphate.
There are no particular requirements for the spray-
drying process other than conventional. The slurry is
normally heated to a temperature of from about 60C to
about 90C, preferably from about 80C to 90C, and
spray-dried in a counter current of air having an inlet
temperature of from about 250c to about 350C,
; preferably from about 275C to about 325C, and an
outlet temperature of from about 90C to 125~C,
preferably from 95C to about 110C.
The pH of the slurry is not critical, which means that
the aqueous slurry composition as defined comprising the
preferably acidic film-forming polymeric material can be
spray-dried at its natural phi
The high active content spray-dried bleach activator
granules of the invention show the combined
characteristics of excellent stability when stored in a
detergent or bleach composition, improved mechanical
strength and attrition resistance upon handling, as well
; as good dispersibility and dissolution rate on addition
to the wash and/or bleach solution.
33~
C 7197 (R)
In addition, they generally have a bulk density which
can be varied within the range of 300 to about 850
grams/litre, and a weight average particle size of from
about 150 em to 2000 em, preferably from about 500 em to
1500 em, thereby matching the values of particulate
detergent or cleaning compositions so as to be usable
for direct incorporation therein without undue
segregation. The adjustments of these values are not
part of the invention, but are measures within the
routine skill of the artisan.
The present invention also encompasses bleaching
compositions, laundry detergent and laundry additive
compositions comprising the bleach activator granules
detailed herein. Bleaching compositions according to the
invention suitably contain from 5% to 99 5%, preferably
from 20% to 90% by weight of peroxide compound bleaching
agent and from 0.5% to 95%, preferably from 10% to 80%
by weight of bleach activator composition. Laundry
compositions according to the invention generally
contain from 2% to 40%, preferably from 5% to 25% by
weight of detersive surfactant selected from anionic,
nonionic, cationic, ampholytic and zwitterionic
surfactants and mixtures thereof and from 0.1% to 20%,
preferably from 0.5% to 10% by weight of the water-
soluble organic peroxyacid bleach precursor. In such
laundry compositions the bleach activator granules
generally comprise from 0.5% to 40%, preferably from 1
to 10% by weight of the laundry composition, and the
base composition comprises from 25~ to 99.5%, preferably
from 35% to 75% by weight of the laundry composition. In
addition, the laundry compositions generally comprise
one or more inorganic or organic detergency builders in
a total level of from 15~ to 90%, preferably from 20% to
60% by weight of the laundry composition, and peroxide
compound bleaching agent at a level of from 5% to 35%,
; preferably from 8~ to 20% by weight ox the laundry
::
C 7197 (R)
composition.
A wide range of surfactants can be used in the laundry
compositions of the invention. US-A-4,111,855 and US-A-
3,995,669 contain detailed listing of typical detersivesurfactants.
Suitable synthetic anionic surfactants are water-soluble
salts of C8-C22 alkyl benzene sulphonates, C8-C22 alkyl
sulphates, C10-Cl8 alkyl polyethoxy ether sulphates, C8-
C24 paraffin sulphanates, alpha-C12-C24 olefin
sulphonates, alpha-sulphonated C6-C20 fatty acids and
their esters, C10-Cl8 alkyl glyceryl ether sulphonates,
fatty acid monoglyceride sulphates and sulphonates,
especially those prepared prom coconut oil, C8-C12 alkyl
phenol polyethoxy ether sulphates, 2-acyloxy Cg-C23
alkane-1-sulphonates, and beta-alkyloxy C8-C20 alkane
sulphonates.
A particularly suitable class of anionic surfactants
includes water-soluble salts, particularly the alkali
metal, ammonium and alkanolammonium salts or organic
sulphuric reaction products having in their molecular
structure an alkyl or alkaryl group containing from 8 to
22, especially from 10 $o 20 carbon atoms and a
sulphonic acid or sulphuric acid ester group. (Included
in the term "alkyl" is the alkyl portion of acyl
groups.)
Examples of this group of synthetic detergents are the
sodium and potassium alkyl sulphates, especially those
: obtained by sulphating the higher alcohols (C8_18)
carbon atoms produced by reducing the glycerides of
: tallow or coconut oil and sodium and potassium alkyl
benzene sulphonates, in which the alkyl group contains
prom 9 to 15, especially 11 to 13, carbon atoms, in
straight chain or branched chain configuration, e.g.
3 3
C 7197 (R)
11
those of the type described in US-A-2,220,099 and US-A-
2,477,383 and those prepared from alkylbenzenes obtained
by alkylation with straight chain chloroparaffins (using
aluminium trichloride catalysis) or straight chain
olefins (using hydrogen fluoride catalysis Especially
valuable are linear straight chain alkyl benzene
sulphonates in which the average of the alkyl group is
about 11.8 carbon atoms, abbreviated as cl1 8 L~S, and
C12-C15 methyl branched alkyl sulphates.
The alkane chains of the foregoing non-soap anionic
surfactants can be derived from natural sources such as
coconut oil or tallow, or can be made synthetically as
for example using the Ziegler or Oxo processes. Water
solubility can be achieved by using alkali metal,
ammonium or alkanolammonium cations; sodium is
preferred.
Suitable fatty acid soaps herein can be selected from
the ordinary alkali metal (sodium, potassium), ammonium,
and alkylolammonium salts of higher fatty acids
containing from 8 to 24, preferably from 10 to 22 and
especially from 16 to 22 carbon atoms in the alkyl
chain. Particularly useful are the sodium and potassium
salts of the mixtures of fatty acids derived from tallow
and hydrogenated fish oil.
Mixtures ox anionic surfactants are particularly
suitable herein, especially mixtures of sulphonate and
sulphate surfactants in a weight ratio of from 5:1 to
1:5, preferably from 5:1 to 1:1, more preferably from
5:1 to 1.5:1. Especially preferred is a mixture of an
alkyl benzene sulphonate having from 9 to 15, especially
11 to 13 carbon atoms in the alkyl radical, the cation
3~ being an alkali metal, preferably sodium; and either an
alkyl sulphate having from 10 to 20, preferably 12 to 18
carbon atoms in the alkyl radical or an ethoxy sulphate
~23~
C 7197 (R)
12
having from 10 to 20~ preferably 10 to 16 carbon atoms
in the alkyl radical and an average degree of
ethoxylation of 1 to 6, having an alkali metal cation,
preferably sodium.
The nonionic surfactants useful in the present invention
are condensates of ethylene oxide with a hydrophobic
moiety to provide a surfactant having an average
hydrophilic-lipophilic balance (HLB) in the range from 8
to 17, preferably from 9.5 to 13.5, more preferably from
10 to 12.5.
Examples of suitable nonionic surfactants include the
condensation products sf primary or secondary aliphatic
alcohols having from 8 to 24 carbon atoms, in either
straight chain or branched chain configuration, with
from 2 to 40 moles, preferably 2 to moles of ethylene
oxide per mole of alcohol. Preferably, the aliphatic
alcohol comprises between 9 and 18 carbon atoms and is
~0 ethoxylated with between 2 and 9, desirably between 3
and 8 moles of ethylene oxide per mole of aliphatic
alcohol. The preferred surfactants are prepared from
primary alcohols which are either linear (such as those
derived from natural fats or prepared by the Ziegler
process from ethylene, e.g. myristyl, cetyl, stearyl
alcohols), or partly branched such as the Lutensols
(RTM), Dobanols (RTM) and Neodols (RTM) which have about
25% 2-methyl branching ( Lutensol (RTM) being a Trade
Name of BASF, Dobanol (RTM~ and Neodol (RTM) being Trade
Names of Shell), or Synperonics (RTM), which are
understood to have about 50% 2-methyl branching
(Synperonic (RTM) is a Trade Name of I.C.I.) or thy
primary alcohols having more than 50% branched chain
structure sold under the Trade Name Lial by
Liquichimica. Specific examples of nonionic surfactants
falling within the scope of the invention include
Dobanol (RTM) 45-4, Dobanol (RTM) 45-7, Dobanol (RTM)
i3 ;~ ~3~ J
C 7197 (R)
13
45-9, Dobanol (RTM) 91-2.5, Dobanol (RTM) 91-3, Dobanol
(RTM) 91-4, Dobanol (RTM) 91-6, Dobanol (RTM) 91-8,
Dobanol (RTM) 23-6.5, Synperonic (RTM) 6, Synperonic
(RTM) 14, the condensation products of coconut alcohol
alcohol with an average of between 5 and 12 moles of
ethylene oxide per mole ox alcohol, the coconut alkyl
portion having from 10 to 14 carbon atoms, and the
condensation products of tallow alcohol with an average
of between 7 and 12 moles of ethylene oxide per mole of
alcohol, the tallow portion comprising essentially
between 16 and 22 carbon atoms. Secondary linear alkyl
ethoxylates are also suitable in the present
compositions, especially those ethoxylates of the
Tergitol series having from 9 to 15 carbon atoms in the
alkyl group and up to 11, especially from 3 to 9, ethoxy
residues per molecule.
Other suitable nonionic surfactants include the
condensation products of C6-C12 alXyl phenols with from
3 to 30, preferably 5 to 14 moles ox ethylene oxide, an
the compounds formed by condensing ethylene oxide with a
hydrophobic base formed by the condensation of propylene
oxide with propylene glycol, such synthetic nonionic
detergents being available on the market under the Trade
Name of "Pluronic (RTM)" supplied by Wyandotte Chemicals
Corporation.
Especially preferred nonionic surfactants for use herein
are the Cg-C15 primary alcohol ethoxylates containing 3-
8 moles of ethylene oxide per mole of alcohol,particularly the C12-C15 primary alcohols containing 6-8
moles of ethylene oxide per mole of alcohol.
Cationic surfactants suitable for use herein include
quaternary ammonium ~urfactants and surfactants of a
semi-polar nature, for example amine oxides. Suitable
quaternary ammonium surfactants are selected from mono
~5~3
C 7197 (R)
14
Cg-C16, preferably C10-C14 N-alkyl or alkenyl ammonium
surfactants wherein remaining N positions are
substituted by methyl, hydroxyethyl or hydroxypropyl and
the corresponding di-C6-C1o N-alkyl or alkenyl ammonium
surfactants. Suitable amine oxides are selected from
mono C8-C20, preferably C10-C14 N-alkyl or alkenyl amine
oxides and propylene-1,3-diamine dioxides wherein the
remaining N positions are again substituted by methyl,
hydroxyethyl or hydroxypropyl.
Suitable detergent builder salts useful herein can be of
the polyvalent inorganic and polyvalent organic types,
or mixtures thereof. Non-limiting examples of suitable
water-soluble, inorganic alkaline detergent builder
salts include the alkali metal carbonates, borates,
phosphates, pyrophosphates, tripolyphosphates and
bicarbonates.
Organic builder/chelating agents that can be
incorporated include citric acid, nitrilotriacetic and
ethylenediamine tetraacetic acids and their salts,
organic phosphonates derivatives such as those disclosed
in US-A-3,213,030, US-A-3,433,021, US-A-3,29~,121 and
US-A-2,599,807, and carboxylic acid builder salts such
as those disclosed in US-A-3,308,067. Preferred
chelating agents include nitrilotriacetic acid (TNA),
nitrilo(trimethylene phosphonic acid) (NTMP),
ethylenediamine tetra~methylene phosphonic acid) (EDTMP)
and diethylenetriamine penta(methylene phosphonic acid)
(DETPMP). Nixtures of organic and/or inorganic builders
can be used herein. One such mixture of builders is
disclosed in CA-A-755,038, e.g. a ternary mixture of
sodium tripolyphosphate, trisodium nitrilotriacetate,
and trisodi~m ethane-l-hydroxy-1,1-diphosphonate.
A further class of builder salts is the insoluble
aluminosilicate type which functions by cation exchange
~3~
C 7197 (R)
to remove polyvalent mineral hardness and heavy metal
ions from solution. A preferred builder of this type has
the formulation Naz(A102)z(SiO2)yOxH20 wherein z and y
are inteyers of at least 6, the molar ratio of z to y is
in the range from 1.0 to 0.5 and x is an integer from 15
to 264. Compositions incorporating builder salts of this
type form the subject of GB-A-1,429,143, DE-A-2,433,485
and DE-A-2,525,778.
An alkali metal, or alkaline earth metal, silicate can
also be present in granular compositions of the
invention. The alkali metal silicate is preferably from
3% to 15%7 Suitable silicate solids have a molar ratio
of SiO2/alkali metal2O in the range from 1.0 to 3.3,
more preferably from 1.5 to 2Ø
The compositions herein will normally contain peroxide
compounds as bleaching components. In general, the
bleach is selected from inorganic peroxy salts, hydrogen
peroxide, hydrogen peroxide adducts, and organic
peroxyacids and salts thereof. Suitable inorganic
peroxygen bleaches include sodium perborate mono- and
tetrahydrate, sodium percarbonate, sodium persilicate,
urea-hydrogen peroxide addition products and the
clathrate 4Na2S04:2H202:1NaCl. Suitable organic bleaches
include peroxylauric acid, peroxyoctanoic acid,
peroxynonanoic acid, peroxydecanoic acid,
diperoxydodecanedioic acid, diperoxyazelaic acid, mono-
and diperoxyphthalic acid and mono- and
dipèroxyisophthalic acid.
The compositions of the invention can be supplemented by
; all manner of detergent and laundering components,
inclusive of suds suppressors, enzymes, fluorescers,
soil-suspending agents, anti-caking agents, pigments,
perfumes, fabric-conditioning agents etc.
'J~j ~J
C 7197 (R)
16
Suds suppressors are represented by materials of the
silicone, wax, vegetable and hydrocarbon oil and
phosphate ester varieties. Suitable silicone suds-
controlling agents include polydimethylsiloxanes having
a molecular weight in the range from 200 to 200,000 and
a kinematic viscosity in the range from 20 to 2,000,000
mm2/s, preferably from 3000 to 30,000 mm2/s, and
mixtures of siloxanes and hydrophobic silanated
(preferably trimethylsilanated) silica having a particle
size in the range from about 10 nm to 20 nm and a
specific surface area above 50 m2/g. Suitable waxes
include microcrystalline waxes having a melting point in
the range from 65C to lOO~C, a molecular weight in the
range from 4000-1000, and a penetration value of at
least 6, measured at 77C by ASTM-D1321, and also
paraffin waxes, synthetic waxes and natural waxes.
Suitable phosphate esters include mono- and/or di-C16-
C22 alkyl or alkenyl phosphate esters, and the
corresponding mono- and/or di-alkyl or alkenyl ether
phosphates containing up to 6 ethoxy groups per
molecule.
Enzymes suitable for use herein include those discussed
in US-A-3,519,570 and US-A-3,533,139. Suitable
fluorescers include Blankophor (RTM) MBBH (Bayer A&) and
Tinopal (RTM) CBS and EMS (Ciba-Geigy). Suitable fabric-
conditioning agents include smectite-type clays as
disclosed in GB-A-1,400,898 and di-C12-C24 alkyl or
alkenyl amines and ammonium salts.
Antiredeposition and soil suspension agents suitable
herein include cellulose derivatives such as
methylcellulose, carboxymethylcellulose and
hydroxyethylcellulose, and homo- or co-polymeric
polycarboxylic acids or their salts in which the
polycarboxylic acid comprises at least two carboxyl
radicals separated prom each other by not more than two
Jo
C 7197 (R)
17
carbon atoms. Polymers of this type are disclose in GB-
A~1,596,765. Preferred polymers include copolymers or
salts thereof of maleic anhydride with ethylene,
methylvinyl ether, acrylic acid or methacrylic acid, the
maleic anhydride constituting at least 20 mole percent
of the copolymer. These polymers are valuable for
improving whiteness maintenance, fabric ash deposition,
and cleaning performance on clay, proteinaceous and
- oxidizable soils in the presence of transition metal
impurities.
Laundry additive products comprising bleaching or
laundry detergent compositions in water-releasable
combination with a non-particulate carrier as described
in EP-A-96566 and EP-A-99197, are also suitable herein.
Laundry products comprising a laundry detergent
composition and a bleaching composition comprising the
bleach activator granules and peroxide bleach in
separate packs or in two-compartment sachets are also
suitable herein.
; Example I
A spray-dried granular bleach activator of the following
composition:
% bv weiaht
Sodium-p-benzoyloxybenzene sulphonate (SBOBS) 65
Polyacrylic acid (Versicol E9) * 5
30 Sodium sulphate 30
Trace water up to 100%
* M.W. 75,000
was prepared in the following manner:
.:
100 Kg of an aqueous slurry composition was prepared
consisting of about 40% by weight of water, 39% by
weight of SBOBS, 3% by weight of polyacrylic acid and
. .
C 7197 (R)
18
18% sodium sulphate. This slurry was heated to a
temperature of about 85OC and pumped to a 1.8 m diameter
spray-drying tower through a nozzle of siæe 2 mm at a
pressure of about 35 bar. Counter-current air of about
275-300C was let in at a velocity of 0.4 meter/sec,
which left the tower at a temperature of about 100C.
The spray-dried bleach activator particles collected at
the bottom of the spray-drying tower were non-dusty
granules of regular, somewhat rounded shape of a size
varying from about 300 to 1000 em, which upon cooling
and storage showed no substantial sign of attrition and
degradation, i.e. the product had good particle
strength.
Upon addition to a wash solution with some stirring, a
rapid dissolution rate was observed.
Example II
The following granular laundry detergent compositions
were prepared by a combined spray-drying and dry-mixing
process.
25 Composition (% by weiqht) A B C
: Spray-dried base Powder
Sodium alkylbenzene sulphonate 6.0 6.5 9.0
Fatty alcohol-7 ethoxylate 3.0 3.0 1.5
Sodium soap 5.0 5.0
30 Sodium triphosphate 33.0 - -
Sodium aluminosilicate (Zeolite A) - 40.0 24.0
Sodium carbonate - - 2.0
Maleic ac~d/acrylic acid copolymer
(Sokalan CP5 ex BASF) - - 4.0
35 Alkaline silicate 6.0 8.0
Sodium sulphate 21.0 16.0 30.0
Sodium carboxymethyl rellulose O.5 0.5 0.5
C 7197 (R)
19
EDTA 0.2 0.2 0.2
Fluorescer 0.3 0.3 0.2
Water and minor ingredients ' 6.0 9.5 8.6
Dry-mixinq inqredients
Anti-foaming agent - - 2.5
Sodium perborate monohydrate 15.08.0 13.0
Spray-dried bleach activator
granules of Example I (65% active)4.0 3.0 4.0
10 Proteolyt enzyme
(Savinase~Jex Novo) - - O.5
The above products show excellent bleach activator
stability upon storage and handling.
