Technical field
The present invention relates to stable aqueous compositions comprising
peroxy carboxylic acids (i.e., peracids). These aqueous compositions
according to the present invention are particularly suitable to be used in
various applications such as in laundry applications, or as hard-surface
cleaners or as carpet cleaners, or as denture cleaners or as disinfecting
compositions in general.
Background
A great variety of cleaning compositions have been described in the art.
Indeed, compositions comprising hydrogen peroxide, and/or water soluble
sources thereof including peracids are known. In order to provide such
compositions comprising peracids, it is common practice to use peracid
precursors as a source of said peracids. Peracids are not commonly
commercially available, and if available they may not be used satisfactorily,
because they are not stable and tend to decompose dramatically during
storage in aqueous compositions.
It is therefore an object of the present invention to provide stable aqueous
compositions comprising peracids.
We have now found that this object can be efficiently met by incorporating in
an aqueous composition a dual function peracid. By "dual function peracid" it
is meant herein a peracid which has both a percarboxylic group and a charged
head or a head of higher polarity than the percarboxylic group. Accordingly, it
has now been found that improved stability is obtained by incorporating in an
aqueous composition a dual function peracid having the general formula of
H000C-Ra-Y wherein Ra is a linear or branched alkyl or aryl group of 1 to 30
carbon atoms and Y is SO3 -, N(Rb)3 + or HO (CH2CH2O)n, wherein Rb is a
linear or branched alkyl or aryl group of from 1 to 8 carbon atoms, and n is 1
to 40.
An advantage of the aqueous compositions herein is that they do not
necessarily require the presence of surfactants to perform good cleaning
performance. Thus, the present invention encompasses one embodiment
wherein the aqueous compositions herein are free of surfactants. Indeed, the
dual function peracids according to the present invention not only deliver
excellent bleaching performance but also good cleaning performance. In other
words, these dual function peracids allow to achieve concomitantly stain
removal through solubilization/emulsification of various stains like greasy
stains such as make-up, vegetal oil, spaghetti, and bleaching of bleachable
stains like coffee, tea and the like.
Different types of peracids or precursors thereof have been described in the
art. EP-A-170 386 discloses a bleaching composition which provides in an
aqueous solution an amide substituted peroxyacid of the formula R1-CO-N-R2R5-COOOH
or R1-N-R5-CO-R2-COOOH, wherein R1 is an aryl or alkaryl
group with from 1 to 14 carbon atoms, R2 is an alkylene, arylene or alkarylene
group containing from 1 to 14 carbon atoms, and R5 is H or an alkyl, aryl, or
alkaryl group containing 1 to 10 carbon atoms.
EP-A-267 047 and EP-A-373 743 disclose a peracid precursor having the
formula R-CO-O-C-R'R''-CO-L, wherein R may represent C1-C20 linear or
branched alkyl, alkylethoxylated, cycloalkyl, aryl, substituted aryl, R' and R''
may independently represent H, C1-20 alkylaryl, substituted aryl and NR3+,
wherein R may represent C1-C30 alkyl and L may represent essentially any
useful leaving group which may be displaced in a peroxygen bleaching solution
by perhydroxide anion.
EP-A-390 393 discloses polyglycolate peracid precursors of the formula R-CO-(O-C-R'R''-CO)n-L,
wherein n is an integer from 2 to 10, R is C1-20 linear or
branched alkyl, alkoxylated alkyl, cycloalkyl, aryl alkyaryl, substituted aryl, R'
and R'' are independently H, C1-20 alkyl, C1-20 aryl, C1-20 alkylaryl,
substituted aryl and NR3+ wherein R may represent C1-C30 alkyl and L may
represent essentially any useful leaving group which may be displaced in a
peroxygen bleaching solution by perhydroxide anion.
EP-A-267 046 discloses bleaching compositions comprising a source of
hydrogen peroxide and as a bleach activator of the general formula (i) R-X-(CH2)n-CO-O-N-R1
wherein R represents C1-20 alkyl, alkoxyl, or cycloalkyl,
R1 represents a group which contains at least one carbon atom which is singly
bonded directly to N; n represents an integer of from 1 to 6 and X represents
methylene or a heteroatom, or (ii) R-X-(CH2)n-COO-N=R2, wherein n is as
defined above, R2 represents a group which contains a carbon atom doubly
bonded directly to N, and either X represents a heteroatom, R represents C4-C17
alkyl or both.
EP-A-331 229 discloses quaternary ammonium peHOarboxylic acid precursors
of formula R1R2R3N+-R4-CO-L, corresponding peracids and compositions
comprising them. The bleaching compositions disclosed are powders or non-aqueous
liquid compositions.
GB 1147 871 discloses peracid precursors of the formula SO3M-substituted
benzene ring-OCOR, wherein R is hydrogen or an alkyl radical having 1-7
carbon atoms and M is an alkali metal, ammonium or substituted ammonium
radical, and the corresponding peracid (HOOOCOR). The precursor is said to
possess detergent and emulsifying properties comparable to alkylbenzene
sulphonate on top of its peracid precursor activity. The corresponding peracids
do not have this dual function.
US-4 259 201 discloses granular bleaching compositions with peroxyacid
compounds of the formula HO-O-CO-R-Y wherein R is an alkyl or alkylene
group containing from 1 to 20 carbon atoms and Y may be SO3M, M being
either hydrogen or a cation which preferably provides a wash-water-soluble
and/or water dispersible wash-compound.
Summary of the invention
The present invention encompasses an aqueous composition comprising from
0.1% to 40% by weight of the total composition of a peracid of the formula
H000C-Ra-Y wherein Ra is a linear or branched alkyl or aryl group of 1 to 30
carbon atoms, and Y is SO3 -, N(Rb)3 + or HO(CH2CH2O)n, wherein Rb is a
linear or branched alkyl or aryl group of from 1 to 8 carbon atoms, and n is an
integer of 1 to 40, or mixtures thereof.
In another embodiment the present invention encompasses a peracid, suitable
for use in an aqueous composition according to the present invention, said
peracid having the formula H000C-Ra-Y wherein Ra is a linear or branched
alkyl or aryl group of 1 to 30 carbon atoms and Y is HO(CH2CH2O)n, wherein
n is an integer of 1 to 40.
The present invention further encompasses a process for forming a peracid
having the formula H000C-Ra-Y wherein Ra is a linear or branched alkyl or aryl
group of 1 to 30 carbon atoms and Y is HO(CH2CH2O)n, wherein n is an
integer of 1 to 40, said process comprising the step of reacting in an aqueous
medium the corresponding peracid precursor with hydrogen peroxide or a
water-soluble source thereof.
In yet another embodiment the present invention further encompasses a
peracid precursor of the formula HO-(CH2-CH2O)n-Ra-CO-O-CO-Ra-(OCH2-CH2)n-OH
or HO-(CH2-CH2O)n-Ra-CO-OH, wherein Ra is a linear or
branched alkyl or aryl group of 1 to 30 carbon atoms, wherein n is an integer of
1 to 40.
Finally, the present invention also encompasses a bleaching composition
comprising a peracid precursor as defined above and hydrogen peroxide or a
water-soluble source thereof.
Detailed description of the invention
Aqueous compositions comprising the peracids
In one embodiment the present invention is an aqueous composition
comprising a dual function peracid.
Thus, the aqueous compositions of the present invention comprise as an
essential ingredient a peracid according to the formula
H000C-Ra-Y
wherein Ra is a linear or branched alkyl or aryl group of 1 to 30 carbon atoms,
preferably 1 to 20, more preferably 2 to 18 and most preferably 4 to 16, Y is
SO3 -, N(Rb)3 + or HO(CH2CH2O)n, wherein Rb is a linear or branched alkyl or
aryl group of from 1 to 8 carbon atoms, preferably 1 to 6 and more preferably
from 2 to 4, and n is an integer of 1 to 40, preferably from 2 to 20 and more
preferably 2 to 12.
Particularly suitable peracids to be used herein include
HOOOC-(CH2)5-SO3-, HOOOC-(CH2)7N(CH3)3 +, HOOOC-(CH2)3-(OCH2CH2)3-OH, HOOOC-(CH2)9-(OCH2CH2)10OH, HOOOC-(CH2)15-(OCH2CH2)3-OH or mixtures thereof.
The aqueous compositions of the present invention comprise from 0.1% to 40%
by weight of the total composition of said dual function peracid or mixtures
thereof, preferably from 1 % to 20%, more preferably from 1.5% to 18% and
most preferably from 2% to 15%.
It has now been found that the aqueous compositions of the present invention
comprising such a dual function peracid exhibit improved chemical stability
upon storage.
Indeed, the aqueous compositions according to the present invention
comprising a peracid as described hereinabove generally do not undergo more
than 30% available oxygen loss, in one month at 20 °C, more preferably not
more than 50% available oxygen loss. Peracid concentration can be measured
by analysing the peracid available oxygen (often abbreviated to Avox). Test
method to evaluate peracid Avox is done via chromatography (see F. Di Furia
et. alt., Gas-liquid chromatography method for determination of peracids,
Analyst, vol. 109, August 1984, p. 985-987; or ibidem vol. 113, May 1988, p.
793-795).
It is believed that in aqueous medium the dual function peracids form micelles.
In these micelles, the charged head or the head of higher polarity (e.g.
ethoxylated groups) than the percarboxylic group of the dual function peroxide
is oriented towards the water phase while the percarboxylic group is oriented
towards the inner part of the micelles. This results in percarboxylic groups that
are protected, i.e., they are less subject to hydrolysis.
Another advantage of the aqueous compositions of the present invention is that
they exhibit at the same time excellent bleaching performance as well as
excellent cleaning performance on different types of stains including greasy
stains due to the presence of one single ingredient, the dual function peracid.
However, in applications where it is intended to clean heavily soiled surfaces,
the aqueous compositions according to the present invention may further
comprise optional ingredients including surfactants, as well as other optional
ingredients selected from the group consisting of hydrogen peroxide or a water-soluble
source thereof, soil suspending agents, builders, chelants, bleach
activators, radical scavengers, pigments, enzymes, dye transfer inhibitors,
solvents, buffering agents, suds suppressing agents, photobleaching agents,
dyes, perfumes and mixtures thereof.
The aqueous compositions according to the present invention may be used as
laundry detergent, as laundry pretreaters, i.e., compositions which are
dispensed and left to act onto fabrics before they are washed, or as laundry
additives to be used together with detergents to boost their performance.
These compositions may also be particularly suitable as dishwashing
compositions to be used either in the dishwashing machines or by hand, or as
carpet cleaners to be used either by direct application onto the carpets or in
carpet cleaning machines, or as toilet bowl cleaners or as hard surface
cleaners or as denture cleaners.
Particular peracids
In another embodiment the present invention is a particular dual function
peracid, suitable for use in the aqueous compositions herein. Said dual
function peracid according to the present invention has the general formula
H000C-Ra-Y wherein Ra is a linear or branched alkyl or aryl group of 1 to 30
carbon atoms, preferably from 1 to 20, more preferably from 2 to 18 and most
preferably from 4 to 16, and Y is HO (CH2CH2O)n, wherein n is an integer of 1
to 40, preferably is 2 to 20 and more preferably 2 to 12.
Preferred peracids herein are:
HOOOC-(CH2)3-(OCH2CH2)3-OH; HOOOC-(CH2)9-(OCH2CH2)3OH; HOOOC-(CH2)15-(OCH2CH2)3-OH; HOOOC-(CH2)11-(OCH2CH2)3-OH; HOOOC-(CH2)3-(OCH2CH2)10OH; HOOOC-(CH2)9-(OCH2CH2)10OH; HOOOC-(CH2)15-(OCH2CH2)10-OH; HOOOC-(CH2)11-(OCH2CH2)10-OH; HOOOC-(CH2)15-(OCH2-CH2)7-OH; HOOOC-(CH2)9-(OCH2-CH2)14-OH, HO-(CH2-CH2O)14-(CH2)9-COOOH or mixtures thereof.
Said peracids have the advantage to act both as a surfactant, i.e., that they
possess detergent and emulsifying properties comparable to ethoxylated
nonionic surfactants and as peracids.
The process for forming the particular peracids
The dual function peracids hereinbefore may be formed by a process
comprising the step of reacting in an aqueous medium the corresponding
peracid precursor with hydrogen peroxide or a water-soluble source thereof.
Thus, the present invention also encompasses a process for forming such a
peracid.
As a first essential element, the process of the present invention requires the
use of the corresponding peracid precursor or mixtures thereof. By "the
corresponding peracid precursor" it is meant herein a compound that allows to
obtain the desired peracid by reaction in an aqueous medium with hydrogen
peroxide or a source thereof. Peroxidation is the reaction which occurs when
the peracid precursor is combined in an aqueous reaction medium, preferably
an acidic aqueous medium, with hydrogen peroxide or a source thereof.
Accordingly, the present invention also encompasses the peracid precursors of
the formula
HO-(CH2-CH2O)n-Ra-CO-O-CO-Ra-(OCH2-CH2)n-OH,
or HO-(CH2-CH2O)n-Ra-CO-OH,
wherein Ra a linear or branched alkyl or aryl group of from 1 to 30 carbon
atoms, preferably from 1 to 20, more preferably from 2 to 18, and n is an
integer of 1 to 40 and preferably from 2 to 20.
In the present invention the peracid precursor reacts with hydrogen peroxide or
a source thereof to provide the corresponding peracid. Particularly suitable
peracid precursors to be used herein are:
HO-(CH2-CH2O)10-(CH2)9-CO-O-CO-(CH2)9-(OCH2-CH2)10-OH, HO-(CH2-CH2O)3-(CH2)11-CO-O-CO-(CH2)11-(OCH2-CH2)3-OH, HO-(CH2-CH2O)7-(CH2)15-CO-O-CO-(CH2)15-(OCH2-CH2)7-OH, HO-(CH2-CH2O)14-(CH2)9-CO-O-CO-(CH2)9-(OCH2-CH2)14-OH, HO-(CH2-CH2O)7-(CH2)15-COOH, HO-(CH2-CH2O)10-(CH2)11-COOH, HO-(CH2-CH2O)14-(CH2)9-COOH, or mixtures thereof.
Particularly preferred herein are HO-(CH2-CH2O)10-(CH2)9-CO-O-CO-(CH2)9-(OCH2-CH2)10-OH,
and HO-(CH2-CH2O)3-(CH2)15-COOH.
As a second essential element, the process of the present invention requires
the use of hydrogen peroxide or a water-soluble source thereof or mixtures
thereof.
As used herein a hydrogen peroxide source refers to any compound which
produces hydrogen peroxide when said compound is in contact with water.
Suitable water-soluble sources of hydrogen peroxide for use herein include
percarbonates, and perborates. Hydrogen peroxide is most preferred to be
used herein.
By "aqueous medium" it is meant herein that the reaction is conducted in
presence of water. The amount of water used depends on the end product
desired and is at the discretion of the process operator. It is often convenient
to use the required amount of water either directly when contacting the
precursor and hydrogen peroxide or a source thereof or in a subsequent step
so as to provide an aqueous composition that has a peracid concentration of
from 0.1% to 40% by weight of the total composition as defined hereinbefore.
Typically, the process according to the present invention requires at least 1.1
moles of hydrogen peroxide or a water-soluble source thereof per molar
equivalent of the precursor, preferably at least 1.5 and more preferably at least
2.
Accordingly, in the preferred embodiment where a solution of hydrogen
peroxide or a water-soluble source thereof is used in the process of the present
invention said solution comprises from 15% to 90% by weight of hydrogen
peroxide or a water-soluble source thereof or mixtures thereof, more preferably
from 20% to 80% and most preferably from 25% to 70%.
Typically, in the process according to the present invention the peracid
precursor is reacted with hydrogen peroxide or a water-soluble source thereof
in presence of an aqueous solution of a strong acid or mixtures thereof. By
"strong acid" it is meant herein an acid having its first pka below 3, preferably
below 2 and more preferably below 1. Said aqueous solution of strong acids
may serve as the reaction aqueous medium and as a catalyst. Said strong
acids include mineral acids and/or organic sulphonic acid. Preferred strong
acids to be used herein are sulphuric acid, phosphonic acid and/or methane
sulphonic acid.
In the process according to the present invention said aqueous solution of a
strong acid or mixtures thereof, comprises from 90% to 98% by weight of said
strong acid, more preferably from 95% to 98% and most preferably from 97% to
98%. Accordingly, the present process is typically conducted in the acidic
range at a pH below 7, preferably up to 5, more preferably up to 2, most
preferably below 0.5.
By using such aqueous solution of a strong acid it is possible to enable the
reaction to occur at a convenient rate without the use of elevated reaction
temperature. The temperature at which the present process is conducted also
depends on the concentration of the solution of hydrogen peroxide or a source
thereof used. For example, if a very concentrated solution of hydrogen
peroxide is used (e.g., 70%), the reaction is preferably conducted around 20°C.
If a less concentrated solution of hydrogen peroxide is used (e.g., 36%), the
reaction is preferably conducted at room temperature, e.g., 25°C or higher. For
convenience, coupled with safety considerations, the reaction temperature is
maintained in many embodiments in the range that is from 0°C to 40°C.
The process of the present invention allows to form not only peracid-containing
aqueous compositions being raw material aqueous compositions but also, fully
formulated aqueous detergent compositions, i.e., compositions incorporating
further ingredients commonly used in the detergent field.
Accordingly, the process of forming said peracid may further comprise a step
where at least one ingredient, other than water, hydrogen peroxide or a water-soluble
source thereof and peracid precursor is provided.
The additional ingredient provided is preferably selected from the group
consisting of surfactants, soil suspending agent, builders, chelants, bleach
activators, radical scavengers, pigments, enzymes, dye transfer inhibitors,
solvents, buffering agents, suds suppressing agents, photobleaching agents,
dyes, perfumes and the like, and mixtures thereof. Depending on the intended
end use of the aqueous compositions according to the process of the present
invention, different combinations of these optional ingredients may be provided
in the process herein.
Aqueous compositions comprising the precursor for the particular peracid
The present invention also encompasses aqueous compositions comprising a
peracid precursor as defined hereinbefore, hydrogen peroxide or a water-soluble
source thereof and optionally an additional ingredient as defined herein
above.
Typically, said aqueous compositions comprise from 0.1 % to 40% by weight of
the total composition of said peracid precursor, or mixtures thereof, preferably
from 0.5% to 30%, and more preferably from 1% to 20% and from 0.1% to 40%
by weight of the total composition of hydrogen peroxide or a water-soluble
source thereof, preferably from 0.5% to 30% and more preferably from 1% to
20%.
These aqueous compositions according to the present invention may be used
as laundry detergent, as laundry pretreaters, i.e. compositions which are
dispensed and left to act onto fabrics before they are washed, or as laundry
additives to be used together with detergents to boost their performance.
These compositions may also be particularly suitable as dishwashing
compositions to be used either in the dishwashing machines or by hand, or as
carpet cleaners to be used either by direct application onto the carpets or in
carpet cleaning machines, or as toilet bowl cleaners or as hard surface
cleaners or as denture cleaners.
Optionals
The following optional ingredients may be added in the compositions according
to the present invention. Accordingly, the compositions according to the present
invention may comprise up to 50% by weight of the total composition of a
surfactant or mixtures thereof, preferably from 0.01% to 30% and more
preferably from 0.1% to 25%. Surfactants for use herein are well known in the art
and include anionic, nonionic, amphoteric, zwitterionic and cationic surfactants
and mixtures thereof. The surfactants suitable for use herein are compatible with
hydrogen peroxide and sources thereof and peracids herein. They also
contribute to the cleaning performance of a composition herein.
Particularly suitable anionic surfactants to be used herein include water soluble
salts or acids of the formula ROSO3M wherein R is preferably a C6-C24
hydrocarbyl, preferably an alkyl or hydroxyalkyl having a C10-C20 alkyl
component, more preferably a C12-C18 alkyl or hydroxyalkyl, and M is H or a
cation, e.g., an alkali metal cation (e.g., sodium, potassium, lithium), or
ammonium or substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl
ammonium cations and quaternary ammonium cations, such as tetramethyl-ammonium
and dimethyl piperdinium cations and quaternary ammonium cations
derived from alkylamines such as ethylamine, diethylamine, triethylamine, and
mixtures thereof, and the like).
Other suitable anionic surfactants to be used herein include alkyl-diphenylether-sulphonates
and alkyl-carboxylates. Other anionic surfactants can
include salts (including, for example, sodium, potassium, ammonium, and
substituted ammonium salts such as mono-, di- and triethanolamine salts) of
soap, C9-C20 linear alkylbenzenesulfonates, C8-C22 primary or secondary
alkanesulfonates, C8-C24 olefinsulfonates, sulfonated polycarboxylic acids
prepared by sulfonation of the pyrolyzed product of alkaline earth metal
citrates, e.g., as described in British patent specification No. 1,082,179, C8-C24
alkylpolyglycolethersulfates (containing up to 10 moles of ethylene oxide); alkyl
ester sulfonates such as C14-16 methyl ester sulfonates; acyl glycerol
sulfonates, fatty oleyl glycerol sulfates, alkyl phenol ethylene oxide ether
sulfates, paraffin sulfonates, alkyl phosphates, isethionates such as the acyl
isethionates, N-acyl taurates, alkyl succinamates and sulfosuccinates,
monoesters of sulfosuccinate (especially saturated and unsaturated C12-C18
monoesters) diesters of sulfosuccinate (especially saturated and unsaturated
C6-C14 diesters), acyl sarcosinates, sulfates of alkylpolysaccharides such as
the sulfates of alkylpolyglucoside (the nonionic nonsulfated compounds being
described below), branched primary alkyl sulfates, alkyl polyethoxy
carboxylates such as those of the formula RO(CH2CH2O)kCH2COO-M+
wherein R is a C8-C22 alkyl, k is an integer from 0 to 10, and M is a soluble
salt-forming cation. Resin acids and hydrogenated resin acids are also
suitable, such as rosin, hydrogenated rosin, and resin acids and hydrogenated
resin acids present in or derived from tall oil. Further examples are given in
"Surface Active Agents and Detergents" (Vol. I and II by Schwartz, Perry and
berch). A variety of such surfactants are also generally disclosed in U.S.
Patent 3,929,678, issued December 30, 1975 to Laughlin, et al. at Column 23,
line 58 through Column 29, line 23 (herein incorporated by reference).
Preferred anionic surfactants for use in the compositions herein are the alkyl
benzene sulfonates, alkyl sulfates, alkyl alkoxylated sulfates, and mixtures
thereof.
Suitable nonionic surfactants to be used herein are fatty alcohol ethoxylates
and/or propoxylates which are commercially available with a variety of fatty
alcohol chain lengths and a variety of ethoxylation degrees. Indeed, the HLB
values of such alkoxylated nonionic surfactants depend essentially on the
chain length of the fatty alcohol, the nature of the alkoxylation and the degree
of alkoxylation. Surfactant catalogues are available which list a number of
surfactants, including nonionics, together with their respective HLB values.
Suitable chemical processes for preparing the nonionic surfactants for use
herein include condensation of corresponding alcohols with alkylene oxide, in
the desired proportions. Such processes are well known to the man 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.
Accordingly, suitable nonionic surfactants for use herein are Dobanol R 91-2.5
(HLB=8.1; R is a mixture of C9 and C11 alkyl chains, n is 2.5 and m is 0), or
Lutensol R TO3 (HLB=8; R is a C13 alkyl chains, n is 3 and m is 0), or
Lutensol R AO3 (HLB=8; R is a mixture of C13 and C15 alkyl chains, n is 3
and m is 0), or Tergitol R 25L3 (HLB= 7.7; R is in the range of C12 to C15
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 m is 0), or Dobanol R 23-2
(HLB=6.2; R is a mixture of C12 and C13 alkyl chains, n is 2 and m is 0), or
Dobanol R 45-7 (HLB=11.6; R is a mixture of C14 and C15 alkyl chains, n is 7
and m is 0) Dobanol R 23-6.5 (HLB=11.9; R is a mixture of C12 and C13 alkyl
chains, n is 6.5 and m is 0), or Dobanol R 25-7 (HLB=12; R is a mixture of C12
and C15 alkyl chains, n is 7 and m is 0), or Dobanol R 91-5 (HLB=11.6; R is a
mixture of C9 and C11 alkyl chains, n is 5 and m is 0), or Dobanol R 91-6
(HLB=12.5 ; R is a mixture of C9 and C11 alkyl chains, n is 6 and m is 0), or
Dobanol R 91-8 (HLB=13.7 ; R is a mixture of C9 and C11 alkyl chains, n is 8
and m is 0), Dobanol R 91-10 (HLB=14.2 ; R is a mixture of C9 to C11 alkyl
chains, n is 10 and m is 0), or mixtures thereof. Preferred herein are
Dobanol R 91-2.5 , or Lutensol R TO3, or Lutensol R AO3, or Tergitol R 25L3,
or Dobanol R 23-3, or Dobanol R 23-2, or mixtures thereof. These
DobanolR surfactants are commercially available from SHELL. These
LutensolR surfactants are commercially available from BASF and these
Tergitol R surfactants are commercially available from UNION CARBIDE.
Other nonionic surfactants include fatty acid C6-C24 alkanolamides, C6-C20
polyethylglycol ethers, polyethylene glycol with molecular weight 1000 to 80000
and glucose amides and alkyl pyrrolidones.
Suitable amphoteric surfactants to be used herein include betaine and
sulphobetaine surfactants, derivatives thereof or mixtures thereof. Suitable
betaine and sulphobetaine surfactants to be used herein are the
betaine/sulphobetaine and betaine-like detergents wherein the molecule
contains both basic and acidic groups which form an inner salt giving the
molecule both cationic and anionic hydrophilic groups over a broad range of pH
values. Some common examples of these detergents are described in U.S.
Pat. Nos. 2,082,275, 2,702,279 and 2,255,082, incorporated herein by
reference. Preferred betaine and sulphobetaine surfactants herein are
according to the formula
wherein R1 is an alkyl radical containing from about 1 to about 24 carbon
atoms, preferably from 8 to 18, and more preferably from 12 to 14, wherein R2
and R3 contain from 1 to 3 carbon atoms, and preferably 1 carbon atom,
wherein n is an integer from 1 to 10, preferably from 1 to 6 and more preferably
is 1, Y is selected from the group consisting of carboxyl and sulfonyl radicals
and wherein the sum of R1, R2 and R3 radicals is from 14 to 24 carbon atoms,
or mixtures thereof.
Examples of particularly suitable betaine surfactants include C12-C18 alkyl
dimethyl betaine such as coconutbetaine and C10-C16 alkyl dimethyl betaine
such as laurylbetaine. Coconutbetaine is commercially available from Seppic
under the trade name of Amonyl 265®. Laurylbetaine is commercially available
from Albright & Wilson under the trade name Empigen BB/L®.
Other suitable amphoteric surfactants to be used herein include amine oxides
having the following formula R1R2R3NO wherein each of R1, R2 and R3 is
independently a saturated substituted or unsubstituted, linear or branched alkyl
groups of from 1 to 30 carbon atoms, preferably of from 6 to 30 carbon atoms,
more preferably of from 10 to 20 carbon atoms, and most preferably of from 8
to 18 carbon atoms. Preferred amine oxides for use herein are for instance
natural blend C8-C10 amine oxides as well as C12-C16 amine oxides
commercially available from Hoechst. Suitable short chain amine oxides to be
used according to the present invention are amine oxides having the following
formula R1R2R3NO wherein R1 is a C6 to C10 alkyl group, preferably a C8 to
C10 alkyl group 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 methyl groups.
R1 may be a saturated linear or branched alkyl group. Preferred short chain
amine oxides for use herein are for instance natural blend C8-C10 amine
oxides available from Hoechst.
Suitable cationic surfactants to be used herein include derivatives of
quaternary ammonium, phosphonium, imidazolium and sulfonium compounds.
Preferred cationic surfactants for use herein are quaternary ammonium
compounds wherein one or two of the hydrocarbon groups linked to nitrogen
are a saturated, linear or branched alkyl group of 6 to 30 carbon atoms,
preferably of 10 to 25 carbon atoms, and more preferably of 12 to 20 carbon
atoms, and wherein the other hydrocarbon groups (i.e. three when one
hydrocarbon group is a long chain hydrocarbon group as mentioned
hereinbefore or two when two hydrocarbon groups are long chain hydrocarbon
groups as mentioned hereinbefore) linked to the nitrogen are independently
substituted or unsubstituted, linear or branched, alkyl chain of from 1 to 4
carbon atoms, preferably of from 1 to 3 carbon atoms, and more preferably are
methyl groups. The counterion used in said quaternary ammonium compounds
are selected from the group of methyl sulfate, or methylsulfonate, and the like.
Particularly preferred cationic surfactants to be used herein are trimethyl
quaternary ammonium compounds like myristyl trimethylsulfate, cetyl
trimethylsulfate and/or tallow trimethylsulfate. Such trimethyl quaternary
ammonium compounds are commercially available from Hoechst, or from
Albright & Wilson under the trade name EMPIGEN CM®.
Suitable zwitterionic surfactants contain both cationic and anionic hydrophilic
groups on the same molecule at a relatively wide range of pH's. The typical
cationic group is a quaternary ammonium group, although other positively
charged groups like phosphonium, imidazolium and sulfonium groups can be
used. The typical anionic hydrophilic groups are carboxylates and sulfonates,
although other groups like sulfates, phosphonates, and the like can be used. A
generic formula for some preferred zwitterionic surfactants is
R1-N+(R2)(R3)R4X-
wherein R1 is a hydrophobic group; R2 and R3 are each C1-C4 alkyl, hydroxy
alkyl or other substituted alkyl group which can also be joined to form ring
structures with the N; R4 is a moiety joining the cationic nitrogen atom to the
hydrophilic group and is typically an alkylene, hydroxy alkylene, or polyalkoxy
group containing from 1 to 4 carbon atoms; and X is the hydrophilic group
which is preferably a carboxylate or sulfonate group. Preferred hydrophobic
groups R1 are alkyl groups containing from 8 to 22, preferably less than 18,
more preferably less than 16 carbon atoms. The hydrophobic group can
contain unsaturation and/or substituents and/or linking groups such as aryl
groups, amido groups, ester groups and the like. In general, the simple alkyl
groups are preferred for cost and stability reasons.
Other specific zwitterionic surfactants have the generic formulas:
R1-C(O)-N(R2)-(C(R3)2)n-N(R2)2 (+)-(C(R3)2)n-SO3 (-)
or
R1-C(O)-N(R2)-(C(R3)2)n-N(R2)2 (+)-(C(R3)2)n-COO(-)
wherein each R1 is a hydrocarbon, e.g. an alkyl group containing from 8 up to
20, preferably up to 18, more preferably up to 16 carbon atoms, each R2 is
either a hydrogen (when attached to the amido nitrogen), short chain alkyl or
substituted alkyl containing from one to 4 carbon atoms, preferably groups
selected from the group consisting of methyl, ethyl, propyl, hydroxy substituted
ethyl or propyl and mixtures thereof, preferably methyl, each R3 is selected
from the group consisting of hydrogen and hydroxy groups and each n is a
number from 1 to 4, preferably from 2 to 3, more preferably 3, with no more
than one hydroxy group in any (C(R3)2) moiety. The R1 groups can be
branched and/or unsaturated. The R2 groups can also be connected to form
ring structures. A surfactant of this type is a C10-C14 fatty
acylamidopropylene(hydroxypropylene)sulfobetaine that is available from the
Sherex Company under the trade name "Varion CAS sulfobetaine"®.
Any soil suspending polycarboxylate polymer known to those skilled in the art
can be used in the compositions according to the present invention such as
homo- or co-polymeric polycarboxylic acids or their salts including
polyacrylates and copolymers of maleic anhydride or/and acrylic acid and the
like. Indeed, such soil suspending polycarboxylate polymers can be prepared
by polymerizing or copolymerizing suitable unsaturated monomers, preferably
in their acid form. Unsaturated monomeric acids that can be polymerized to
form suitable polymeric polycarboxylates include acrylic acid, maleic acid (or
maleic anhydride), fumaric acid, itaconic acid, aconitic acid, mesaconic acid,
citraconic acid and methylenemalonic acid. The presence in the polymeric
polycarboxylates herein of monomeric segments, containing no carboxylate
radicals such as vinylmethyl ether, styrene, ethylene, etc. is suitable provided
that such segments do not constitute more than about 40% by weight.
Particularly suitable polymeric polycarboxylates to be used herein can be
derived from acrylic acid. Such acrylic acid-based polymers which are useful
herein are the water-soluble salts of polymerized acrylic acid. The average
molecular weight of such polymers in the acid form preferably ranges from
about 2,000 to 10,000, more preferably from about 4,000 to 7,000 and most
preferably from about 4,000 to 5,000. Water-soluble salts of such acrylic acid
polymers can include, for example, the alkali metal, ammonium and substituted
ammonium salts. Soluble polymers of this type are known materials. Use of
polyacrylates of this type in detergent compositions has been disclosed, for
example, in Diehl, U.S. Patent 3,308,067, issued march 7, 1967.
Acrylic/maleic-based copolymers may also be used as a preferred soil
suspending polycarboxylic polymer. Such materials include the water-soluble
salts of copolymers of acrylic acid and maleic acid. The average molecular
weight of such copolymers in the acid form preferably ranges from about 2,000
to 100,000, more preferably from about 5,000 to 75,000, most preferably from
about 7,000 to 65,000. The ratio of acrylate to maleate segments in such
copolymers will generally range from about 30:1 to about 1:1, more preferably
from about 10:1 to 2:1. Water-soluble salts of such acrylic acid/maleic acid
copolymers can include, for example, the alkali metal, ammonium and
substituted ammonium salts. Soluble acrylate/maleate copolymers of this type
are known materials which are described in European Patent Application No.
66915, published December 15, 1982. Particularly preferred is a copolymer of
maleic / acrylic acid with an average molecular weight of about 70,000. Such
copolymers are commercially available from BASF under the trade name
SOKALAN CP5.
Any soil suspending polyamine polymer known to those skilled in the art may
also be used herein. Particularly suitable polyamine polymers for use herein
are polymers having polyalkoxymoiety are alkoxylated polyamines. Such
materials can conveniently be represented as molecules of the empirical
structures with repeating units:
wherein R is a hydrocarbyl group, usually of 2-6 carbon atoms; R
1 may be a
C
1-C
20 hydrocarbon; the alkoxy groups are ethoxy, propoxy, and the like, and
y is 2-30, most preferably from 10-20; n is an integer of at least 2, preferably
from 2-20, most preferably 3-5; and X
- is an anion such as halide or
methylsulfate, resulting from the quaternization reaction.
The most highly preferred polyamines for use herein are the so-called
ethoxylated polyethylene amines, i.e., the polymerized reaction product of
ethylene oxide with ethyleneimine, having the general formula:
when y = 2-30. Particularly preferred for use herein is an ethoxylated
polyethylene amine, in particular ethoxylated tetraethylenepentamine, and
quaternized ethoxylated hexamethylene diamine.
The compositions according to the present invention may comprise up to 10%
by weight of the total composition of a soil suspending polycarboxylate polymer
and/or polyamine polymer, preferably from 0.01% to 5% and more preferably
from 0.1% to 1%.
Suitable chelating agents to be used in the compositions according to the
present invention include any chelating agent known to those skilled in the art.
Suitable chelating agents include for example phosphonate chelating agents,
polyfunctionally-substituted aromatic chelating agents, amino carboxylate
chelating agents, other chelating agents like ethylene diamine N,N'- disuccinic
acid and mixtures thereof.
Suitable phosphonate cheating agents to be used herein may include
ethydronic acid, alkali metal ethane 1-hydroxy diphosphonates 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 phosphonates. The phosphonate
compounds 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 penta methylene
phosphonates (DETPMP). Such phosphonate cheating agents are
commercially available from Monsanto under the trade name DEQUEST®.
Polyfunctionally-substituted aromatic chelating agents may also be useful in the
compositions herein. See U.S. patent 3,812,044, issued May 21, 1974, to
Connor et al. Preferred compounds of this type in acid form are
dihydroxydisulfobenzenes such as 1,2-dihydroxy -3,5-disulfobenzene.
A preferred biodegradable chelating agent for use herein is ethylene diamine
N,N'- disuccinic acid, or alkali metal, or alkaline earth, ammonium or 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.
Suitable amino carboxylate chelants to be used herein include ethylene
diamine tetra acetates, diethylene triamine pentaacetates, diethylene triamine
pentaacetate (DTPA), N-hydroxyethylethylenediamine triacetates, nitrilotriacetates,
ethylenediamine tetrapropionates, triethylenetetraaminehexaacetates,
ethanoldiglycines, propylene diamine tetracetic 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
amino carboxylate to be used herein is diethylene triamine penta acetic acid
(DTPA).
The compositions according to the present invention may comprise up to 5% by
weight of the total composition of a chelating agent or mixtures thereof,
preferably from 0.01% to 3% and more preferably from 0.05% to 1.5%.
The compositions according to the present invention may further comprise a
radical scavenger, or mixtures thereof, as an optional ingredient. Suitable
radical scavengers for use herein include the well-known substituted mono and
di hydroxy benzenes and their analogs, alkyl and aryl carboxylates and mixtures
thereof. Preferred such radical scavengers for use herein include di-tert-butyl
hydroxy toluene (BHT), hydroquinone, di-tert-butyl hydroquinone, mono-tert-butyl
hydroquinone, tert-butyl-hydroxy anysole, benzoic acid, toluic acid,
catechol, t-butyl catechol, benzylamine, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)
butane, n-propyl-gallate or mixtures thereof and highly preferred is
di-tert-butyl hydroxy toluene. Radical scavengers when used, are typically
present herein in amounts ranging from 0.001% to 2% by weight of the total
composition and preferably from 0.001% to 0.5% by weight.
The compositions according to the present invention may further comprise a
builder system. Any conventional builder system is suitable for use herein.
Suitable builders for use herein include citric acid, preferably in the form of a
water-soluble salt, derivatives of succinic acid of the formula
R_CH(COOH)CH2(COOH) wherein R is C10-20 alkyl or alkenyl, preferably
C12-16, or wherein R can be substituted with hydroxyl, sulpho sulphoxyl or
sulphone substituents. Specific examples include lauryl succinate, myristyl
succinate, palmityl succinate, 2-dodecenylsuccinate, 2-tetradecenyl succinate.
Succinate builders are preferably used in the form of their water-soluble salts,
including sodium, potassium, ammonium and alkanolammonium salts.
Other suitable builders are oxodisuccinates and mixtures of tartrate
monosuccinic and tartrate disuccinic acid such as described in US 4,663,071.
Further suitable builders for use herein are fatty acid builders including
saturated or unsaturated C10-18 fatty acids, as well as the corresponding
soaps. Preferred saturated species have from 12 to 16 carbon atoms in the
alkyl chain. The preferred unsaturated fatty acid is oleic acid.
The compositions according to the present invention may comprise up to 20%
by weight of the total composition of a builder or mixtures thereof, preferably
from 5% to 10% and more preferably from 0.01% to 5%.
In one embodiment, the aqueous compositions of the present invention
comprising a peracid of the formula H000C-Ra-Y wherein Ra is a linear or
branched alkyl or aryl group of 1 to 30 carbon atoms, and Y is SO3 -, N(Rb)3 +
or HO(CH2CH2O)n, wherein Rb is a linear or branched alkyl or aryl group of
from 1 to 8 carbon atoms, and n is an integer of 1 to 40, or mixtures thereof
may further comprise as an optional ingredient, hydrogen peroxide or a water-soluble
source thereof or mixtures thereof, up to a level of 40%, preferably from
0.1% to 10%.
Suitable sources of hydrogen peroxide to be used herein are any source of
hydrogen peroxide known to those skilled in the art including percarbonates,
perborates, peroxides/hydroperoxides, persilicates, persulphates and mixtures
thereof.
Suitable organic and inorganic peroxides/hydroperoxides for use herein include
diacyl and dialkyl peroxides/hydroperoxides such as dibenzoyl peroxide, t-butyl
hydroperoxide, dilauroyl peroxide, dicumyl peroxide and mixtures thereof.
Suitable preformed peroxyacids for use herein include diperoxydodecandioic
acid DPDA, magnesium perphthalatic acid, perlauric acid, perbenzoic acid,
diperoxyazelaic acid and mixtures thereof.
The compositions according to the present invention may be aqueous
compositions formulated in the form of an emulsion. In this embodiment said
peracid and/or precursor thereof is emulsified by means of a surfactant system
of at least two different surfactants, i.e., at least a hydrophobic surfactant
having an HLB below 11 and at least one hydrophilic surfactant having an HLB
above 11. Indeed, said two different surfactants in order to form emulsions
which are stable must have different HLB values (hydrophilic lipophilic
balance), and preferably the difference in value of the HLBs of said two
surfactants is at least 1, preferably at least 3.
An advantage associated with such aqueous emulsions is that their stability is
further improved as compared to aqueous compositions not formulated in the
form of an emulsion, i.e., the decomposition rate of said peracid is further
reduced during storage.
The compositions according to the present invention in the form of an emulsion
comprise from 1% to 50% by weight of the total composition of said hydrophilic
and hydrophobic surfactants, preferably from 2% to 40% and more preferably
from 3% to 30%. Said compositions according to the present invention in the
form of an emulsion comprise at least from 0.1 % by weight of the total
composition of said hydrophobic surfactant, preferably at least 1% and more
preferably at least 2% and at least from 0.1 % by weight of the total
composition of said hydrophilic surfactant, preferably at least 1% and more
preferably at least 2%.
Preferred to be used in the emulsions of the present invention are the
hydrophobic nonionic surfactants and hydrophilic nonionic surfactants. Said
hydrophobic nonionic surfactants to be used herein have an HLB below 11,
preferably below 10, more preferably below 8 and said hydrophilic surfactants
have an HLB above 11, preferably above 12, more preferably above 13.
Suitable 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 different HLB values (hydrophilic lipophilic balance). The HLB
values of such alkoxylated nonionic surfactants depend essentially on the
chain length of the fatty alcohol, the nature of the alkoxylation and the degree
of alkoxylation. Hydrophilic nonionic surfactants tend to have a high degree of
alkoxylation and a short chain fatty alcohol, while hydrophobic surfactants tend
to have a low degree of alkoxylation and a long chain fatty alcohol. Surfactants
catalogs are available which list a number of surfactants including nonionics,
together with their respective HLB values.
Suitable chemical processes for preparing the nonionic surfactants for use
herein include condensation of corresponding alcohols with alkylene oxide, in
the desired proportions. Such processes are well known to the man 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. Examples of adequate nonionic surfactant
systems would comprise a hydrophobic nonionic surfactant with for instance an
HLB of 6, such as a Dobanol R 23-2 and a hydrophilic nonionic surfactant with
for instance an HLB of 15, such as a Dobanol R 91-10. Another suitable
nonionic surfactant system comprises a Dobanol R 23-6.5 (HLB about 12) and
a Dobanol R 23 (HLB below 6).
Apart from hydrophobic and hydrophilic surfactants being nonionic surfactants
any other types of surfactants known in the art and able to form emulsions
may be used according to the present invention.
Other suitable hydrophilic surfactants to be used in the present invention may
be anionic surfactants in particular sulfonate and sulfate surfactants. The like
anionic surfactants are well-known in the art and have found wide application in
commercial detergents. These anionic surfactants include the C8-C22 alkyl
benzene sulfonates (LAS), the C8-C22 alkyl sulfates (AS), unsaturated sulfates
such as oleyl sulfate, the C10-C18 alkyl alkoxy sulfates (AES) and the C10-C18
alkyl alkoxy carboxylates. The neutralizing cation for the anionic synthetic
sulfonates and/or sulfates is represented by conventional cations which are
widely used in detergent technology such as sodium, potassium or
alkanolammonium.
The emulsions herein may further comprise other surfactants which should
however not significantly alter the weighted average HLB value of the overall
composition.
The present invention will be further illustrated by the following examples.
Examples
The compositions hereinafter are according to the present invention and
contain the following ingredients in the following proportions (% by weight):
Compositions % weight | I | II | III | IV | V |
HOOOC-(CH2)5-SO3- | 4 | -- | -- | -- | 1 |
HOOOC-(CH2)7N(CH3)3 + | -- | 2 | -- | -- | -- |
HOOOC-(CH2)3-(OCH2CH2)3-OH | -- | -- | 1 | -- | -- |
HOOOC-(CH2)9-(OCH2CH2)10OH | -- | -- | 1 | 2.5 | 1 |
HOOOC-(CH2)15-(OCH2CH2)3-OH | -- | -- | -- | 0.5 | 1 |
H2O2 | 4 | -- | 4 | -- | 4 |
DTPA | 0.1 | -- | 0.1 | -- | 0.1 |
BHT | 0.05 | 0.05 | 0.05 | 0.05 | 0.05 |
Water and minors | --------------------up to 100%--------------- |
DTPA is diethylene triamine pentaacetate.
BHT is di-tert-butyl hydroxy toluene |
All these compositions are chemically stable upon prolonged storage periods,
e.g., after one month of storage at ambient temperature (about 20°C) no more
than 30% of available oxygen loss occurs.
Also, these compositions provide excellent cleaning performance even without
the presence of a surfactant, as well as excellent bleaching performance on
different types of stains.
Process for forming a peracid according to the present invention:
A peracid having the formula HOOOC-(CH2)9-(CH2CH2O)3-OH was obtained
by carrying out the following method.
Preparation of the precursor of said peracid:
10-hydroxydecanoic acid commercially available from Aldrich was reacted with
methyl alcohol used in excess, before undergoing an ethoxylation at a
temperature of 120°C to 140°c in presence of ethylen oxide. Then the resulting
compound was submitted to an ester hydrolysis reaction in alkaline water
media to obtain the peracid precursor of the formula HO-(CH2CH2O)3-(CH2)9-COOOH.
Preparation of the peracid perse:
0.02 moles of the precursor of the formula HO-(CH2CH2O)3-(CH2)9-COOOH
was solubilized in 18 grs of a concentrated aqueous solution of sulfuric acid
(95% by weight). Then said solution was contacted under stirring with a
concentrated solution of hydrogen peroxide (70% by weight) that was added
drop by drop up to 100% excess with respect to the precursor of the formula
HO-(CH2CH2O)3-(CH2)9-COOOH. After the addition of said concentrated
solution of hydrogen peroxide, the reaction mixture was stirred at room
temperature (about 20-25°C) for 50 minutes. Thereafter the resulting
composition was diluted with water to get the desired concentration of peracid
in the end product. In this dilution stage other optional ingredients may be
added as chelants, surfactants, radical scavengers and the like.
According to the present invention the following reactions occur to prepare a
peracid having the formula HOOOC-(CH2)9-(CH2CH2O)3-OH:
1. Protection of the carboxylic group
HO-(CH2)9-COOH + MeOH → HO-(CH2)9-COOMe 2. Ethoxylation at 120°C-140°C
3. Ester hydrolysis
HO-(CH2CH2O)3-(CH2)9-COOMe OH- / HO-(CH2CH2O)3-(CH2)9-COOH 4. Peracid formation
HO-(CH2CH2O)3-(CH2)9-COOH + H2O2 → HO-(CH2CH2O)3-(CH2)9-COOOH