Note: Descriptions are shown in the official language in which they were submitted.
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STABI.E EMULSIONS COMPRISING
A HYDROPHOBIC LIQUID lI\iGREDlENT
0 Technical field
The present invention relates to aqueous emulsions comprising a
hydrophobic liquid ingredient.
Backqround
20 Cleaning compositions comprising hydrophobic ingredients such as
bleaching compositions comprising bleach activators have been extensively
described in the art.
More particularly, it is known to formulate bleaching compositions, if they
25 comprise a hydrophobic ingredient like a bleach activator, as an emulsion of
nonionic su.racL;s,lts, see for instance EP-A- ~9~3 170. In said compositions
the bleach activator reacts with hydrogen peroxide to yield a peracid which
is the bleaching species.
30 However a drawback associated with liquid compositions comprising
hydrophobic ingredients, e.g. bleachinç~ compositions co,.".rising bleach
activators, is that they may decompose, i.e., undergo a phase separation
upon long storage period. Indeed, hydrophobic liquid ingredients like bleach
activators or aqueous insolublc or sparingly soluble organic peroxy acids are
35 problematic to use in an aqueous composition as said composition tends to
separate into two dirre~t "L layer phases which can be visualised by the
consumer.
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It is thus an object o~ the present invention to provide a composition
comprising a hydrophobic liquid ingredient, especially a bleaching
composition comprising a hydrophobic liquid ingredient, with improved
physical stability.
The present invention meets the above object in proposing an aqueous
emulsion having a pH of not more than 7, comprising a hydrophobic liquid
ingredient emulsified in said emulsion by a mixture of a hydrophilic amine
oxide surfactant and a hydrophobic surfactant. Indeed, it has now been
10 found that the presence of said hydrophilic amine oxide surfactant gives to
an emuision comprising a hydrophobic liquid ingredient such as a bleach
activator and/or a hydrophobic source of active oxygen, and a hydrophobic
surfactant an increased physical stability, compared to the same emulsion
without said hydrophilic amine oxide surfactant or to the same emulsion but
15 with another hydrophilic surfactant like a hydrophilic nonionic surfactant
instead of said hydrophilic amine oxide surfactant.
An advantage of the present invention is that it allows for great flexibility informulating. Indeed, the ,~,resent invention allows to incorporate any kind of
20 hydrophobic liquid ingredient such as a hydrophobic source of active oxygen
(e.g., diperdodecanoic acid) and/or a bleach activator, in an aqueous
cornposition through emulsification. Although the present invention finds a
preferred application in formulating bleaching compositions comprising
bleach activators and/or hydrophobic sources of active oxygen, th~ present
26 invention is also applicable to the formulation of aqueous cornpositions
which comprise any hydrophobic liquid ingredient like perfumes.
Another advantage of the present invention is that, due to the presence of
hydrophilic amine oxide surfactants and hydrophobic surfactants like
30 nonionic surfactants, particularly good performance in removing ~lirr~rent
types of soils including bleachable stains, greasy stains, enzymatic stains in
laundry application as well as bacterial soils in household cleaning
application is provided.
35 A further advantage of the present invention is that the bleaching emulsions
herein are also chemically stable.
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EP-A-598 170 discloses aqueous cleaning and bleaching compositions (pH
0.5-6) comprising hydrogen peroxide and a hydrophobic liquid ingredient,
said hydrophobic liquid ingredient being emulsified by a mixture of two
nonionic surfactants having different HLB. EP-A-598 170 further mentions
5 that said compositions are preferably free of other surfactant types. No
amine oxide surfactants are disclosed.
Co-pending European patent application n~ 94870184.2 discloses a
thickened acidic composition comprising a source of active oxygen, a
10 quaternary ammonium and a C6-C10 amine oxide. This patent application
mentions that other surractants of all types may be added. However, no
emulsions are disclosed.
WO ~15/20028 discloses grease emulsifying dishwashing compositions
15 comprising a C10-C22 amine oxide Surractarlt and a detergent surfactant
selected from the group of anionic, nonionic, amphoteric and zwitterionic
surfactants. Chlorine and oxygen bleaches are mentioned as optional
ingredients without further specifying them. No emulsion is expressly
disclosed.
EP-A- 92 932 discloses a composition suitable for use in bleaching or
disinfection containing hydrogen peroxide and a specific bleach activator,
said composition being in the form of an emulsion. The emulsifier may be
fatty acid esters or fatty ethers or amines of a polyhydroxy substituted
25 compound or a polyethoxylate. No amine oxide su, ractanLs are disclosed.
US-4 541 944 discloses emulsions comprising hydrogen peroxide, a specific
bleach activator and an emulsifier, said emulsifier having an HLB being
suLsLa.~Liall~y the same as that of the activator. Such emulsifiers include
30 ethoxylated nonionic SUI r~Cta~ IL~. Other surfactants include nonionic,
cationic, anionic and amphotheric surfactants. No amine oxide surfactants
are disclosed.
EP-A-610 010 ~Jiscloses an aqueous bleaching composition comprising a
35 water insoluble peroxy acid ~e.g. an imido peroxycarboxylic acid~, a water
imr. ~iscible solvent, said solvent comprising the dispersed phase of a
solvent/water emulsion. Said compositions may further comprise
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surfactants like anionic surfactants and/or ethoxylated nonionic surfactants.
No amine oxide surfactants are disclosed.
GB 1 092 149 discloses alkaline stable oil-in-water ernulsions (ptl 11.7 to
13) of nonionic su, racLants (e.g. ethoxylated nonionic surfactant) and a
5 detergent surfactant being selected from the group of sultaine detergent,
phosphine oxide detergent and amine oxide detergent. Said compositions
may comprise other ingredients like a germicide.
Summarv of the invention
The present invention is an aqueous emulsion having a pH of no more than
7, comprising a hydrophobic liquid ingredient and an emulsifying systern
15 comprising a hydrophilic amine oxide surfactant and a hydrophobic
surfactant.
The ~,resent invention also enco~.-,uasses a process for the manufacture of
said emulsion.
{)etailed desc-i~,lion of the invention
25 The emulsions according to the present invention are aqueous.
Accordingly, the emulsions accordi--g to the present invention comprise
from 10% to 9~% by weight of the total emulsion of water, prefer~,bly from
30% to 90%, most preferc,l,ly from 50% to 70%. Deionized water is
preferal~ly used.
The emulsions of the present invention are formulated at a pH of no more
than 7. Formulating the emulsions according to the present invention in this
acidic pH range contributes to the stability of the emulsion. In a preferred
embodiment, the emulsions are formulated at a pH below 7, pleferably of
35 frorn 0 to !~, and more preferably of from 0 to 4. The pH of the emulsion
can be trimmed by all means available to the man skilled in the art.
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The emulsions according to the present invention comprise, as an essential
element, a hydrophobic liquid ingredient, or mixtures thereof. As used
herein, the term "hydrophobic liquid ingredient" refers both to iiquid
ingredients, and solid materials which are dissolved in a hydrophobic liquid
5 phase prior to incorporation into the emulsions of the invention. By
hydrophobic, it is meant herein any material which is not substantially and
stably miscible in water. Hydrophobic ingredients herein typically have an
I ILB below 11, preferably below 10.
10 Suitable hydrophobic liquid ingredients to be used herein include bleach
activators, hydrophobic sources of active oxygen, perfumes, hydrophobic
solvents, enzymes, hydrophobic radical scavengers, hydrophobic chelating
agents, hydrophobic brighteners, polymers and mixtures thereof. As used
herein, the term hydrophobic liquid ingredient refers to single ingredients or
15 mixtures thereof.
Preferred hydrophobic liquid ingredients to be used in the emulsions
according to the present invention include a hydrophobic source of active
oxygen, or mixtures thereof.
20 The source of active oxygen according to the present invention acts as an
oxidising agent, it increases the ability of the emulsions to remove colored
stains and organic stains in general, to destroy malodorous molecules and to
kill germs.
Suitable hydrophobic sources of active oxygen to be used herein include
25 hydrophobic dialkylperoxides, hydrophobic diacylperoxide, hydrophobic
prefGr...ed percarboxylic acids, as well as hydrophobic organic and inorganic
peroxides. Suitable hydrophobic organic peroxides include hydrophobic
diacyl and dialkyl peroxides such as dibenzoyl peroxide, dilauroyl peroxide,
dicumyl peroxide, and all peroxides with a number of carbon above 7, or
30 mixtures thereof. Suitable hydrophobic preformed peroxyacids for use in
the emulsions according to the pres~, ~ L invention include
diperoxydodecandioic acid (DPDA), magnesium perphthalic acid, perlauric
acid, diperoxy~el~ic acid and all peracids with a number of carbon above 7,
or mixtures Ll .ereof .
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Other preferred hydrophobic liquid ingredients to be used in the emulsions
according to the present invention are bleach activators. By bleach
activator, it is meant herein any compound which reacts with hydrogen
peroxide to form a peracid. In the case of bleach activators, such
5 hydrophobic bleach activators typically belong to the class of esters,
amides, imides, or anhydrides. Examples of suitable compounds of this
type are disclosed in British Patent GB 1 586 769 and GB 2 143 231 and a
method for their formation into a prilled form is described in European
Published Patent Application EP-A-62 523. Suitable examples of such
0 compounds to be used herein are tetracetyl ethylene diamine (TAED),
sodium 3,5,E; trimethyl hexanoyloxybenzene sulphonate, diperoxy
dodecanoic acid as described for instance in US 4 818 425 and nonylamide
of peroxyadipic acid as described for instance in US 4 259 201 and n-
nonanoyloxybenzenesulphonate (NOBS). Also suitable are N-acyl
15 caprolactam selected from the group consisting of substituted or
unsubstituted benzoyl caprolactam, octanoyl caprolactam, nonanoyl
caprolactam, hexanoyl caprolactam, decanoyl caprolactam, undecenoyl
caprolactam, formyl caprolactam, acetyl caprolactam, propanoyl
caprolactam, butanoyl caprolactam pentanoyl caprolactam or mixtures
20 thereof. A particular family of bleach activators of interest was disclosed in
EP 624 154, and particularly preferred in that family is acetyl triethyl citrate(ATC). Acetyl triethyl citrate has the advantages that it is environmentally
friendly as it eventually degrades into citric acid and alcohol. Furthermore,
acetyl triethyl citrate has a good hydrolytical stability in the product upon
25 storage and it is an efficient bleach activator. Finally, it provides good
building capacity to the con position. As used herein and unless otherwise
specified, the term bJeach activator includes mixtures of bleach activators.
The emuisions according to the present invention comprise from 0.1% to
40% by weight of the totai emulsion of said liquid hydrophobic ingredient,
30 or rnixtures thereof, preferably from 0. 1% to 20%, and more prefel &LIy
from 0.1% to ~5%.
In the emulsions according to the present invention, said hydrophobic liquid
ingredient is emulsified ll ~erei, . by means of an emulsifying system
35 comprising a hydrophilic amine oxide surfactant and a hydrophobic
su.ract~llt. In tha ~rese,-t invention said two dirrere~.L su.fs~;ldnls, i.e., the
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hydrophilic amine oxide surfactant and the hydrophobic surfactant, have
different H~B values (hydrophilic lipophilic balance), and the difference in
value of the HLBs of said two surfactants is preferably at least 1, more
preferably at least 3.
Thus, the emulsions according to the present invention comprise, as an
essential element, a hydrophobic surfactant, or mixtures thereof. By
"hydrophobic surfactant" it is meant herein a surfactant having an HLB
below 1 1, preferably below 10, more preferably below 9. Particularly
10 preferred to be used herein are hydrophobic nonionic surfactants. Indeed,
the hydrophobic nonionic surfactants to be used herein have excellent
grease cutting properties, i.e. they have a solvent effect which contributes
to hydrophobic soils removal.
15 Accordingly, the emulsions according to the present invention comprise
from 0. 1% to 30% by weight of the total emulsion of said hydrophobic
surfactant or mixtures thereof, preferably from 1% to 15% and more
preferably from 1 % to 1 0% .
20 Suitable hydrophobic nonionic surfactants for use herein include alkoxylated
fatty alcohols preferably, fatty alcohol ethoxylates and/or propoxylates.
Indeed, a great variety of such alkoxylated fatty alcohols are commercially
available which have very dirrerellt HLB values (hydrophilic lipophilic
balance). The HLB values of such alkoxylated nonionic surfactants depend
25 essentially on the chain length of the fatty alcohol, the nature of the
alkoxylation and the degree of alkoxylation. Hydrophobic nonionic
su. racla..ls suitable to be used herein tend to have a low degree of
alkoxylation and a long chain fatty alcohol. Surfactants catalogs are
available which list a number of su.raclants including nonionics, together
30 with their respective HLB values.
Suitable chemical processes for preparing the nonionic su,racta"ts for use
herein include condensation of corresponding alcohols with alkylene oxide,
in the desired proportions. Such processes are well known to the man
35 skilled in the art and have been extensively described in the art. As an
alternative, a great variety of alkoxylated alcohols suitable for use herein is
commercially available from various suppliers.
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Preferred hydrophobic nonionic surfactants to be used in the emulsions
according to the present invention are surfactants having an HLB below 11
and being according to the formula RO-(C2H40)n(C3tl60)mH, wherein R is
a C6 to C22 alkyl chain or a C6 to C2g alkyl benzene chain, and wherein
n+m is from 0.5 to 6 and n is from O to 6 and m is from O to 6 and
preferably n+m is from 0.5 to 5 and, n and m are from O to 5. The
preferred R chains for use herein are the C8 to C22 alkyl chains.
Accordingly, suitable hydrophobic nonionic surfactants for use herein are
0 Dobanol R 91-2.5 (HLB= 8.1; R is a mixture of Cg and C1 1 alkyl chains, n
is 2.5 and m is 0~, or Lutensol R T03 (HLB=8; R is a mixture of C13 and
C1 5 alkyl chains, n is 3 and m is 0), or Tergitol R 25L3 ~HLB= 7.7; R is in
the range of C12 to C1s alkyl chain length, n is 3 and m is 0~, or Dobanol
R 23-3 (HLB--8.1; R is a mixture Of C12 and C13 alkyl chains, n is 3 and
ts m is 0), or Dobanol R 23-2 (HLB= 6.2; R is a mixture of C12 and C13
alkyi chains, n is 2 and m is 0), or mixtures thereof. Preferred herein are
Dobanol R 23-3, or Dobanol R 23-2, Lutensol R T03, or mixtures thereof.
These Dobanol R surfactants are commercially available from SHELL. These
Lutensol R surfactants are commercially available from BASF and these
20 Tergitol R surfactants are cor,.r,~ercially avsilable from UNION CAR~IDE.
Other suitable hydrophobic nonionic sulrd~;~dllls to be used herein are non
alkoxylated su.ra-,-La.)Ls. An example is Dobanol R 23 (HLB<3 ).
25 The emulsions accGr.J;"g to the present invention comprise, as a further
essential ele,-,e"t, a hydrophilic amine oxide su, ra~;tarit, or mixtures thereof.
Suitable hydrophiiic amine oxide surfactants to be used according to the
presenl invention are amine oxide su.rac~anls having the following formula
R1R2R3NO wherein R1 is a C6 to C24 alkyl group"~referaL,ly a C6 to C18
30 alkyl group and more ~referaLly a C6 to C12, and wherein R2 and R3 are
independently substituted or unsubstituted, linear or branched alkyl groups
of from 1 to 4 carbon atoms, preferably of from 1 to 3 carbon atoms and
more preferably are rnethyl groups. R1 may be a linear or branched alkyl
group, being saturated or unsaturated. Suitable amine oxide su- racLd~ . for
35 use herein are ,ureferably compatible with any source of active oxygen.
rl efe~ amine oxide su- racld- ~ts for use herein are for instance natural
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blend C8/C10 amine oxide available from Hoechst or C12 amine oxide
available from Hoechst.
The emulsions according to the present invention comprise from 0.1% to
5 40% by weight of the total emulsion of a hydrophilic amine oxide
surfactant, or mixtures thereof, preferably of from 0.5% to 30% and more
preferably of from 1% to 10%.
The emulsions according to the present invention may further comprise
0 other SUrraCtalltS like anionic surfactants, other nonionic surfactants,
zwitterionic su- r~cLa.lLs and/or amphotheric surfactants. Said additional
surracLanLs should however not significantly alter the weighted average HLB
value of the overall emulsion. Also the level of the dirre~ent surfactants
present may be chosen so as to formulate emulsions with different
15 viscosities. Thus by appropriately choosing the level of the dirrerent
surfactants, the viscosity of the emulsion may be increased and thus may
be particularly suitable to be used on inclined surfaces such as bath tubs,
sinks or toilet bowls.
20 In a preferred embodiment of the emulsions of the present invention, the
emulsifying system meets the equation:
weight%A weight%B
HLB(X) = x HLB(A) ~ x HLB(B) and weight %A+ weight%B =
2~ 1 00%;
100 1 00
where HLB (X) refers to the HLB of the hydrophobic ingredient to emulsify,
if several hydrophobic ingredients are present X refers to the all of them
30 ~weiyl,led average based on % of each ingredient in the formula), HLB (A)
refers to the HLB of said hydrophilic amine oxide surfactant, or mixtures
thereof, and HLB (B) refers to the HLB of said hydrophobic surfactant, or
mixtures thereof.
35 The emulsions of the present invention are physically stable. By "physically
stable" it is meant herein that said emulsions do not undergo a phase
separation after storage at 50~C for a period of two weeks. Physical
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stability may also be measured by spectrophotometry. In this test method
emulsions are suL~ Led to a temperature gradient. Starting from room
temperature the emulsions temperature is increased by 0.1 ~C per minute
up to when a phase separation occurs. The temperature of the phase
separation is called Cloud Point Temperature CPT. This temperature can be
detected spectrometrically due to a transmittance jump that occurs
concomitantly to the emulsion phase separation.
The emulsions of the present invention comprise as an optional but highiy
preferred ingredient a hydrophilic source of active oxygen, or mixtures
10 thereof. The presence of said hydrophilic source of active oxygen, in
particular hydrogen peroxide, is highly desired when said hydrophobic liquid
ingredient is a bleach activator. Suitable hydrophilic source of active oxygen
include hydrogen peroxide or a water soluble source thereof. As used herein
a hydrogen peroxide source refers to any compound which produces
15 hydrogen peroxide when said compound is in contact with water. Suitable
water-soluble inorganic sources of hydrogen peroxide for use herein include
persulfate, persulfuric acid, percarbonates, metal hydrophilic peroxides,
perborates and persilicate salts.
Suitable persulfate salts or mixtures thereof to be used herein according to
20 the present invention, as a sourca of active oxygen includes monopersulfate
triple salt. One example of monopersulfate salt commercially available is
potassium monopersulfate co-,-,nerci~lise~l by Peroxide Chemie GM~H under
the trade name Curox(g). Other persulfate salts such as dipersulfate salts
commercially available from Peroxide Chemie GMBH can be used in the
25 emulsions according to the present invention.
In addition, other cla-sses of hydrophilic peroxides can be used as an
alternative to hydrogen peroxide and sources thereof or in combination with
hydrogen peroxide and sources thereof.
Examples of hydrophilic peroxides include hydrophilic dialkylperoxides,
30 hydrophilic diacylperoxide, hyJro~l)il;c preformed percarboxylic acids and
hydrophilic organic and inorganic peroxides. Suitable hydrophilic organic
peroxides include all peroxides with a number of carbon atoms below or
equal to 7, or mixtures thereof. Suitable hydrophilic preformed peroxyacids
for use in the emulsions according to the ~rese, ~t invention include
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1 1
diperpimelic acid, perbenzoic acid and all peracids with a number of
carbons below 7, or mixtures thereof.
The emulsions according to the present invention comprise up to 30% by
weight of the total emulsion of said hydrophilic source of active oxygen, or
mixtures thereof, preferably from 0.1% to 20%, and more preferably from
0.1% to 15%.
The bleaching emulsions according to the present invention are also
chemically stable. By "chemically stable" it is meant herein that an
0 emulsion comprising a source of active oxygen such as for instance a
persulfate salt, does not undergo more than 20 % persulfate loss, in one
month at 25~C. Persulfate concentration can be measured by titration
with potassium permanganate after reduction with a solution containing
ammonium ferrous sulphate. Said stability test method is well known in the
art and is reported, for example, on the technical information sheet of Curox
OE commercially available from Interox. Alternatively persulfate
collce~llrdLion can also be measured using a chromatography method
described in the lit~rature for peracids (F. Di Furia et al., Gas-liquid
Chromatography Method for Determination of Peracids, Analyst, Vol 113,
May 1988, p 793-795).
The emulsions according to the present invention may also comprise
optional ingredients including dyes, hydrophilic brighte, ~ers, builders,
pi91l ,e"ts, soil release agents, dye transfer inhibitors, solvents, buffering
25 agents and the like.
The emulsions acco. .li. ~9 to the present invention may further comprise a
chelating agent. Suitable chelating aye,.L~ may be any of those known to
those skilled in the art such as the ones selected from the group comprising
30 phosphonate chelating agents, amino carboxylate chelating agents or other
carboxylate chelating agents, or polyfunctionally-substituted aromatic
- chelating agents or mixtures thereof. These chelating agents further
contribute to the stability of the peroxygen bleach-containing emulsions
herein.
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12
Such phosphonate chelating agents may include etidronic acid ~1-
hydroxyethylidene-bisphosphonic acid or HEDP) as well as amino
phosphonate compounds, including amino alkylene poly (alkylene
phosphonate), alkali metal ethane 1-hydroxy diphosphonates, nitrilo
trimethylene phosphonates, ethylene diamine tetra methylene
phosphonates, and diethylene triamine penta methylene phosphona~es. The
phosphonate cornpounds may be present either in their acid form or as salts
of different cations on some or all of their acid functionalities. Preferred
phosphonate chelating agents to be used herein are diethylene triamine
0 penta methylene phosphonates. Such phosphonate chelants are
commercially available from Monsan~o under the trade name DEQUEST(~3)-
Polyfunctionally-substituted aromatic chelating agents may also be useful in
the compositions herein. See U.S. patent 3,812,044, issued May 21,
15 1974, to Connor et al. P~efer.ed compounds of this type in acid form are
dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,~;-disulfobenzene.
A preferred biodey-ddable chelating agent for use herein is ethylene diamine
N,N'- disuccinic acid, or alkali metal, or alkaline earth, amrnonium or
20 substitutes ammonium salts thereof or mixtures thereof. Ethylenediamine
N,N'- disuccinic acids, especially the (S,S) isomer have been extensively
described in US patent 4, 704, 233, November 3, 1987 to Hartman and
Perkins. Ethylenediamine N,N'- disuccinic acid is, for instance, commercially
available under the tradename ssEDDS(~' from Palmer Research Laboratories.
25 Suitable amino carboxyiate chelating agénts useful herein include ethylene
diamine tetra ace~al~s, diethylene triamine pentaacetates, diethylene
triamine pentoaceldLe (DTPA), N-hydroxyethylethylenediamine triacetates,
nitrilotri-aceldles, ethylenediamine tetraproprionates,
triethyleneteL. aaminehexa-act:LaLes, ethanoldiglycines, propylene di8ll ,in
30 teLracelic acid (PDTA) and methyl glycine di-acetic acid (MGDA), both in
their acid form, or in their alkali metal, ammonium, and substituted
ammonium salt forms. Particularly suitable to be used herein are diethylene
triamine penta acetic acid ~DTPA), propylene diamine tetracetic acid (PDTA)
which is, for instance, commercially available from BASF under the trade
35 narne Trilon FS(B) and methyl glycine di-acetic acid ~MGDA).
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13
Further carboxylate chelating agents to be used herein include malonic acid,
salicylic acid, glycine, aspartic acid, glutamic acid, or mixtures thereof.
Typically, the emulsions according to the present invention comprise up to
5 5% by weight of the total emulsion of a chelating agent, or mixtures thereof,
preferably from 0.01% to 1.5% by weight and more preferably from 0.01%
to 0.5%.
The emulsions according to the present invention may further comprise a
- 10 radical scavenger. Suitable radical scavengers for use herein include the well-
known substituted mono and di hydroxy benzenes and derivatives thereof,
alkyl- and aryl carboxylates and mixtures thereof. Preferred radical
scavengers for use herein include di-tert-butyl hydroxy toluene,
hydroquinone, di-tert-butyl hydroquinone, mono-tert-butyl hydroquinone, tert-
15 butyl-hydroxy anysole, benzoic acid, toluic acid, catechol, t-butyl catechol, 2-
methoxy-phenol, 2-ethoxy-phenol, 4-allyl-catechol, 2-methoxy-4-(2-
propenyl~phenol, benzylamine, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)
butane, as well as n-propyl-gallate. Highly preferred for use herein is di-tert-butyl hydroxy toluene, which is for example commercially available from
20 SHELL under the trade name IONOL CP~. These radical scavengers further
contribute to the stability of the peroxygen bleach-containing emulsions
herein.
25 Typically, the emulsions according to the present invention comprise up to
5% by weight of the total emulsion of a radical scavenger, or mixtures
thereof, preferably from 0.01% to 1.5% by weight and more preferably from
0.01% to 0.5%.
The present invention further encGI~passes a process for the manufacture
of the emulsions described herein. The process according to the present
invention comprises at least three steps:
J
In the first step, a hydrophobic mixture is prepared which comprises at least
said hydrophobic surfactant and said hydrophobic liquid ingredient.
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14
In the second step, a hydrophilic mixture is prepared which comprises at
least said water, and said hydrophilic amine oxide surfactant. Said
hydrophilic mixture preferably further comprises other hydrophilic
5 ingredients which are to be formulated in the emulsion such as hydrophilic
source of active oxygen, dyes, optical brighteners, builders, buffering
agents, and organic and/or inorganic acids to adJust the pH to the desired
value. In this second step the hydrophilic source of active oxygen, if
present, is preferably added last, after said buffering agent has been added.
Naturally, said first and said second steps can be performed in any order,
i.e. second step first is also suitable.
5 In the third step of the process according to the present invention, said
hydrophobic mixture and said hydrophilic mixture are mixed together.
The present invention is further illustrated by the following examples.
Examples
Emulsions are made which cornprise the listed ingredients in the listed
proportions (weight %).
ll lll IV V
Dobanol R 91-2.5 4.9 4.7 4.9 4-7 4-7
C12 amine oxide 2.1 2.3 2.1 2.3 ---
C8/C10 amine oxida --- --- --- --- 2.3
Acetyl triethyl citrate 3.5 --- --- --- -
Hydrogen peroxide 6.0 --- - --- ---
Citric acid 4.0 4.0 --- --- ---
Potassium monopersulfate --- --- 6 6 4
Sulfuric acid --- --- 6 6 ---
Methanesulfonic acid --- --- --- --- 5
Dibenzoyl peroxide --- 3 --- --- ---
Deionized water balance up to 100~
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Compositions I to V were obtained which were stable emulsions, both from
a chemical and a physical standpoint. Also, these emulsions deliver
5 excellent cleaning performance on hard-surfaces and in laundry application.
Compositions I to V are each made by preparing two mixtures. A
hydrophilic mixture is prepared which comprises the water, the amine oxide
surfactant, citric acid if present, methanesulfonic acid if present, and
10 sulfuric acid if present. Hydrogen peroxide, if present or monopersulfate, ifpresent is added in said hydrophilic mixture as last step. A hydrophobic
mixture is prepared which comprises Dobanol R 91-2.5 and acetyl triethyl
citrate, if present and dibenzoyl peroxide, if present.
15 Then said hydrophobic mixture is poured into said hydrophilic mixture, while
mixing .
