Technical Field
[0001] The present invention relates to the cleaning of fabrics in soaking conditions, i.e.,
in conditions where the fabrics are left to soak in a soaking liquor comprising water
and detergent ingredients, either as a first step before a typical washing operation,
or as a single step.
Background of the invention
[0002] Fabric soaking operations have been described in the art. In such soaking operations,
fabrics are left in contact with a soaking liquor for a prolonged period of time typically
ranging from more than 1 hour to overnight or even 24 hours. This laundering process
has the advantage that it maximises the contact time between the fabrics and the key
active ingredients of the soaking liquor. It also has the advantage that it reduces
or eliminates the need for a typical laundering operation involving the need for mechanical
agitation, or that it improves the efficiency of the subsequent typical laundering
operation.
[0003] Such soaking operations are typically desirable to remove tough outdoor dirt from
fabrics, such as particulate soil like mud, silt and/or clays. For example, clays
usually have a microcrystalline mineral structure (e.g., hydrous aluminium silicate
like illite, montmorillonite, kaolinite and the like) with the presence of an organic
fraction. The organic fraction can contain a variety of compounds (e.g., humic acid,
fulvic acid, plant/animal biomass and the like).
[0004] Clays can also contain several kinds of metals (e.g., magnesium, calcium, potassium,
iron and the like). However, such particulate soil is particularly difficult to remove
from fabrics. Indeed, it is believed that the very fine dirt grains like clays or
silt, typically below 0.002 mm in size, can insert among fabric fibers and steadily
stick to the surface of the fibers. This problem is particularly acute with socks
which are most exposed to silt and clay pick-up. Also, such soaking operations are
not fully satisfactory regarding the enzymatic stain removal performance. Enzymatic
stains are typically composed of carbohydrates and proteinaceus soil like blood. It
has now been observed that enzymatic stains may act as a glue for particulate soil
on fabrics, thus removing such enzymatic stains may facilitate the removal of particulate
soil from fabrics.
[0005] It is thus an object of the present invention to improve the removal of particulate
soils, particularly silt, mud and/or clay, as well as enzymatic stains, from fabrics
in a soaking operation.
[0006] It has been found that this object can be met by soaking fabrics in an aqueous soaking
liquor comprising an effective amount of a soaking detergent composition comprising
a dianionic cleaning agent and/or an alkoxylated dianionic cleaning agent, as defined
hereinafter. Indeed, it has been found that a dianionic cleaning agent and/or an alkoxylated
dianionic cleaning agent, in a soaking composition, delivers improved stain removal
performance on tough outdoor dirt like particulate soil and/or enzymatic stains under
soaking conditions (i.e., when left in contact for a prolonged period of time typically
more than 1 hour up to 24 hours), as compared to the stain removal performance delivered
with the same composition being free of a dianionic cleaning agent and/or an alkoxylated
dianionic cleaning agent. Thus, in its broadest aspect the present invention encompasses
a process of soaking fabrics, wherein said fabrics are immersed for more than one
hour in a soaking liquor comprising water and an effective amount of a composition
comprising a dianionic cleaning agent, as defined herein, and/or an alkoxylated dianionic
cleaning agent, as defined herein, then removed from said soaking liquor.
[0007] An advantage of the present invention is that the stain removal performance, when
soaking a fabric in presence of a soaking composition comprising an alkoxylated dianionic
cleaning agent and/or a dianionic cleaning agent, is improved even in the presence
of relatively high levels of hardness ions. Indeed, the presence of hardness ions
(calcium or magnesium ions), which occur naturally in the soaking liquor, in particular,
can reduce surfactant performance. Anionic surfactants are especially sensitive to
hardness ions, reducing surfactant performance, eventually precipitating the surfactant
from the soaking liquor as a calcium or magnesium salt. This phenomen occurs less
when using a dianionic cleaning agent and/or an alkoxylated dianionic cleaning agent.
Accordingly, the soaking detergent manufacturer may make use of builders which are
not the more performing at sequestering free hardness ions, and thus may use less
expensive builders in such a soaking composition.
[0008] Furthermore, it has been found in the preferred embodiment of the present invention
that the stain removal performance on particulate soil and/or enzymatic stains is
further improved by combining said dianionic cleaning agent and/or an alkoxylated
dianionic cleaning agent with a sorbitan ester, as defined hereinafter, in a soaking
detergent composition. Thus, the present invention encompasses a soaking detergent
composition comprising a sorbitan ester and, a dianionic cleaning agent and/or an
alkoxylated dianionic cleaning agent, as defined herein, as well as a process of soaking
fabrics in a soaking liquor formed with said soaking detergent composition.
[0009] An advantage of the present invention is that not only improved particulate soil
removal performance is delivered but also that the soil redeposition on fabrics in
prolonged soaking condition is prevented. Furthermore, the compositions of the present
invention comprising said dianionic cleaning agent and/or an alkoxylated dianionic
cleaning agent together with a sorbitan ester, provide effective stain removal performance
on other types of stains like greasy stains, e.g., bacon, grease, spaghetti sauce
and/or bleachable stains like tea and/or coffee.
Background art
[0010] US 3 755 201 discloses a laundry product with a blue dye stuff, surfactants, a compound
selected from the group of builders, fillers, solvents and adjuvants. These compositions
may be employed in pre-soaking laundry products. Polyoxyethylene sorbitan monostearate
is disclosed. No dianionic cleaning agents and/or alkoxylated dianionic cleaning agents
are disclosed.
[0011] US 3 762 859 discloses laundry detergent compositions comprising surfactants, and
particular dyestuff. Sorbitan esters like sorbitan monolaurate, sorbitan mono-oleate
and mannitan monopalmitate are disclosed. No dianionic cleaning agents and/or alkoxylated
dianionic cleaning agents are disclosed.
Summary of the invention
[0012] The present invention encompasses a soaking composition comprising:
- a sorbitan ester according to the formula C6H9O2 (C2H4O)x R1R2R3, wherein x is an integer of from 0 to 40, R1, R2 are independently OH or (Cn H n+1)COO, and R3 is (Cn H n+1)COO group, where n is an integer of from 11 to 17; and
- a dianionic cleaning agent comprising a structural skeleton of at least five carbon
atoms to which two anionic substituent groups spaced at least three atoms apart are
attached, wherein one anionic substituent group is a sulfate group and the other anionic
substituent is selected from sulfate and sulfonate, and/or
- an alkoxylated dianionic cleaning agent comprising a structural skeleton of at least
five carbon atoms to which two anionic substituent groups spaced at least three atoms
apart are attached, wherein one anionic substituent group is an alkoxy-linked sulfate
group and the other anionic substituent is selected from sulfate and sulfonate, optionally
alkoxy-linked.
[0013] The present invention further encompasses a process of soaking fabrics, wherein said
fabrics are immersed in a soaking liquor comprising water and an effective amount
of a composition as described hereinabove, for an effective
[0014] period of time, then removed from said soaking liquor. In its broadest aspect the
present invention encompasses a process of soaking fabrics, wherein said fabrics are
immersed for more than one hour in a soaking liquor comprising water and an effective
amount of a composition comprising a dianionic cleaning agent, as defined herein,
and/or an alkoxylated dianionic cleaning agent, as defined herein, then removed from
said soaking liquor.
Detailed Description of the invention
[0015] The present invention encompasses a composition and a process of soaking fabrics.
The composition, hereinafter referred to as the soaking composition is used in the
soaking process.
A - The composition:
[0016] The present invention encompasses a composition which comprises a sorbitan ester,
and a dianionic cleaning agent and/or an alkoxylated dianionic cleaning agent.
The sorbitan ester:
[0017] Accordingly, the first essential ingredient of the compositions of the present invention
is a sorbitan ester according to the formula C
6H
9O
2 (C
2H
4O)
x R
1R
2R
3, wherein x is an integer of from 0 to 40, R
1, R
2 are independently OH or (C
n H
n+1)COO, and R
3 is (C
n H
n+1)COO group, where n is an integer of from 11 to 17.
[0018] In the preferred compositions herein, x is 0 or 20, and the most preferred compositions
herein comprise polyethoxylated (20) sorbitan tristearate, i.e. C
6H
9O
2 (C
2H
4O)
20 (C
17 H
35COO)
3, or polyethoxylated (20) sorbitan monostearate, i.e. C
6H
9O
2 (C
2H
4O)
20(OH)
2(C
17 H
35COO), or sorbitan monostearate, i.e. C
6H
9O
2(OH)
2(C
17 H
35COO), or sorbitan monopalmitate, i.e. C
6H
9O
2(OH)
2(C
15 H
31COO), or mixtures thereof.
[0019] All these materials are commercially available under several trade names, such as
Glycosperse TS 20 from Lonza (polyethoxylated sorbitan tristearate), Glycosperse S
20 from Lonza (polyethoxylated sorbitan monostearate), Radiasurf 7145 from Fina (sorbitan
monostearate), Radiasurf 7135 from Fina (sorbitan monopalmitate), Armotan MP from
Akzo (sorbitan monopalmitate).
[0020] It has further been found that combining ethoxylated sorbitan esters with non-ethoxylated
sorbitan esters provides better performance than either kind alone.
[0021] In the soaking composition herein, there should be from 0.01% to 10% of the total
composition of said sorbitan ester or mixtures thereof, preferably from 0.01% to 5%,
most preferably from 0.5% to 5%.
[0022] The second essential ingredient of the compositions of the present invention is a
dianionic cleaning agent and/or an alkoxylated dianionic cleaning agent.
The dianionic cleaning agent
[0023] The dianionic cleaning agent comprises a structural skeleton of at least five carbon
atoms, to which two anionic substituent groups spaced at least three atoms apart are
attached. At least one of said anionic substituent groups is a sulfate group; the
other is a sulfate or sulfonate group, preferably a sulfate group. Said structural
skeleton can for example comprise any of the groups consisting of alkyl, substituted
alkyl, alkenyl, aryl, alkaryl, ether, ester, amine and amide groups.
[0024] The structural skeleton preferably comprises from 5 to 32, preferably 7 to 28, most
preferably 12 to 24 atoms. Preferably the structural skeleton comprises only carbon-containing
groups and more preferably comprises only hydrocarbyl groups. Most preferably the
structural skeleton comprises only straight or branched chain alkyl groups.
[0025] The structural skeleton is preferably branched. Preferably at least 10 % by weight
of the structural skeleton is branched and the branches are preferably from 1 to 5,
more preferably from 1 to 3, most preferably from 1 to 2 atoms in length (not including
the sulfate or sulfonate group attached to the branching).
[0026] Again, the anionic substituent groups present in the dianionic cleaning agents useful
herein are spaced at a distance of at least three atoms from each other. For example,
where one anionic substituent group is attached to a carbon (the first carbon), said
first carbon is attached to a second carbon, which is in turn, attached to a third
carbon and the third carbon is attached to the second anionic substituent group to
give a spacing of three carbon atoms.
[0027] In a preferred aspect of the present invention, at least one anionic substituent
group is substituted at a primary position on the structural skeleton. The anionic
substituent groups are preferably spaced 1-3, 1-4, 1-5, 1-6 or greater apart; a 1-4
substitution for disulfated compounds is most preferred, and 1-4 and 1-5 substitution
for sulfated/sulfonated compounds is most preferred. For full clarity, the term 1-n
substitution is to be interpreted such that 1 indicates an anionic substituent group
located at a given position on the structural skeleton and n indicates the number
of atoms spaced between the first and second anionic substituent groups.
[0028] A preferred dianionic cleaning agent has the formula

where R is an alkyl, substituted alkyl, alkenyl, aryl, alkaryl, ether, ester, amine
or amide group of chain length C
1 to C
28, preferably C
3 to C
24, most preferably C
8 to C
20, or hydrogen; A and B are independently selected from alkyl, substituted alkyl, and
alkenyl groups of chain length C
1 to C
28, preferably C
1 to C
5, most preferably C
1 or C
2, or a covalent bond, and A and B in total contain at least 2 atoms; A, B, and R in
total contain from 4 to 31 carbon atoms; X and Y are anionic groups selected from
the group consisting of sulfate and sulfonate, provided that at least one of X or
Y is a sulfate group; and M is a cationic moiety, preferably a substituted or unsubstituted
ammonium ion, or an alkali or alkaline earth metal ion.
[0029] The most preferred dianionic cleaning agent has the formula as above where R is an
alkyl group of chain length from C
10 to C
18, A and B are independently C
1 or C
2, both X and Y are sulfate groups, and M is a potassium, ammonium, or a sodium ion.
[0030] The dianionic cleaning agent is typically present at levels of incorporation of from
0.01% to 50%, preferably from 0.05% to 10%, more preferably from 0.1% to 5%, and most
preferably from 0.2% to 2% by weight of the soaking composition.
[0031] Preferred dianionic cleaning agents herein include:
(a) 1,3 disulfate compounds, preferably 1,3 C7-C23 (i.e., the total number of carbons
in the molecule) straight or branched chain alkyl or alkenyl disulfates, more preferably
having the formula:

wherein R is a straight or branched chain alkyl or alkenyl group of chain length
from C4 to C18;
(b) 1,4 disulfate compounds, preferably 1,4 C8-C22 straight or branched chain alkyl
or alkenyl disulfates, more preferably having the formula:

wherein R is a straight or branched chain alkyl or alkenyl group of chain length
from C4 to C18; preferred R are selected from octanyl, nonanyl, decyl, dodecyl, tetradecyl, hexadecyl,
octadecyl, and mixtures thereof; and
(c) 1,5 disulfate compounds, preferably 1,5 C9-C23 straight or branched chain alkyl
or alkenyl disulfates, more preferably having the formula:

wherein R is a straight or branched chain alkyl or alkenyl group of chain length
from C4 to C18.
[0032] As will be appreciated more fully from the following discussion of preferred synthesis
methods, the present invention compositions may also comprise some amount of sulfated
alcohols and/or sulfonated alcohols which may comprise (to differing degrees depending
on the reaction conditions used) a portion of the dianionic cleaning agent raw material
used to manufacture the present invention compositions. Such alcohols are typically
compatible with the present invention compositions and may be present as long as the
requisite amount of dianionic cleaning agent is present in the final composition.
Synthesis Methods:
[0033] Known syntheses of certain disulfated surfactants, in general, use an alkyl or alkenyl
succinic anhydride as the principal starting material. This is initially subjected
to a reduction step from which a diol is obtained. Subsequently the diol is subjected
to a sulfation step to give the disulfated product. As an example, US-A-3,634,269
describes 2-alkyl or alkenyl-1,4-butanediol disulfates prepared by the reduction of
alkenyl succinic anhydrides with lithium aluminium hydride to produce either alkenyl
or alkyl diols which are then sulfated. In addition, US-A-3,959,334 and US-A-4,000,081
describe 2-hydrocarbyl-1,4-butanediol disulfates also prepared using a method involving
the reduction of alkenyl succinic anhydrides with lithium aluminium hydride to produce
either alkenyl or alkyl diols which are then sulfated. See also US-A-3,832,408 and
US-A-3,860,625 which describe 2-alkyl or alkenyl-1,4-butanediol ethoxylate disulfates
prepared by the reduction of alkenyl succinic anhydrides with lithium aluminium hydride
to produce either alkenyl or alkyl diols which are then ethoxylated prior to sulfation.
[0034] These compounds may also be made by a method involving synthesis of the disulfated
cleaning agent from a substituted cyclic anhydride having one or more carbon chain
substituents having in total at least 5 carbon atoms comprising the following steps:
(i) reduction of said substituted cyclic anhydride to form a diol; and
(ii) sulfation of said diol to form a disulfate
wherein said reduction step comprises hydrogenation under pressure in the presence
of a transition metal-containing hydrogenation catalyst.
[0035] The cyclic anhydride starting material has a ring structure and comprises an acid
anhydride linkage. Cyclic anhydrides are generally formed by a ring forming condensation
reaction of a single organic compound having a first carboxylic acid (-COOH) functional
group and a second -COY functional group separated from the carboxylic acid functional
group by at least two carbon atoms, wherein Y is usually an -OH, or halogen functionality.
[0036] A specific example of an organic compound which may be condensed to form a cyclic
anhydride is maleic acid which on self-condensation provides maleic anhydride. Maleic
anhydride is readily available commercially. The ring structure of the cyclic anhydride
starting material contains from 4 to 7 carbon atoms, preferably from 4 to 6 carbon
atoms in the ring structure. Most preferably the cyclic anhydride starting material
is based on succinic anhydride which has a 5-membered ring structure containing 4
carbon atoms in the ring.
[0037] The cyclic anhydride starting material is substituted by one or more carbon containing
substituents, such that in total, these substituents contain at least 5 carbon atoms,
preferably from 5 to 25 carbon atoms, more preferably from 7 to 21 carbon atoms. Preferably,
all of the carbon chain substituent(s) comprise either alkyl or alkenyl chains, which
may be branched or unbranched. In one preferred aspect they are essentially unbranched.
In another preferred aspect the chains are primarily monobranched, that is more than
50% by weight of the chains are monobranched. In one preferred aspect the substituted
cyclic anhydride has a single carbon chain substituent. In another preferred aspect
the substituted cyclic anhydride has two carbon chain substituents each having different
points of attachment to the ring structure.
[0038] Substituted alkenylsuccinic and alkylsuccinic anhydrides are suitable starting materials
herein. Preferred anhydrides of this type have the following structures:

where R and R
2 are either H or an alkyl group. In one preferred aspect R
2 is H.
[0039] Linear alkenylsuccinic anhydrides may be obtained in high yield from the single stage
'ene reaction' of maleic anhydride with an alpha-olefin. Branched alkenylsuccinic
anhydrides may be obtained from the single stage 'ene reaction' of maleic anhydride
with an internal olefin, such as those obtainable from the familiar SHOP (tradename
of the Shell Corporation) olefin making process.
[0040] Alkylsuccinic anhydride starting materials can be made by reducing alkenylsuccinic
anhydrides. This reduction can be achieved under the conditions of the catalytic hydrogenation
reduction step as described herein.
[0041] The first step is the reduction of the substituted cyclic anhydride to form a diol.
The reduction step comprises hydrogenation under pressure in the presence of a transition
metal-containing hydrogenation catalyst.
[0042] It is an advantage of this method that under the conditions of the catalytic hydrogenation
reduction step any alkene linkages are also reduced to alkyl linkages. Thus, if an
alkenylsuccinic anhydride is used as the starting material it is reduced via a (single)
reduction step to the diol having alkyl chain substituents, as are desired. This contrasts
with the situation where LiAlH
4, which does not reduce alkene linkages, is used in the reduction step, wherein an
extra step involving the reduction of the alkenyl succinic anhydride to the alkyl
succinic anhydride (via e.g. Pd/hydrogen) must be employed to obtain the desired diol
product.
[0043] The hydrogenation catalyst acts functionally to enhance the efficiency of the reductive
hydrogenation process. For use on a commercial scale it is desirable that the catalyst
is easy to regenerate. Preferably, the catalyst contains a transition metal selected
from the group consisting of the group VIA (particularly Cr), VIIA (particularly Mn),
VIII (particularly Fe, Co, Ni, Ru, Rh, Pd, Pt) and IB (particularly Cu) elements.
Catalysts containing mixtures of any of these transition metals are envisaged as are
catalysts containing other metals including the alkali and alkaline earth metals.
Platinum, paladium, and copper-containing catalysts, particularly copper chromite
(which is commercially available and relatively easy to regenerate) are most preferred.
An alternate synthesis may also utilize supported Pd/Rh catalysts to selectively hydrogenate
maleic anhydride to either THF of butane diol, as described by S.B. Ziernecki, C&EN,
April 3, 1995, pp 20-23.
[0044] The hydrogenation catalyst may advantageously be supported on an inert support material.
The support material can generally comprise an oxide salt comprising a metal selected
from the group consisting of aluminium, silicon and any mixtures thereof. Supports
comprising aluminium oxide or silicon dioxide are especially preferred. Carbon and
clay materials are also suitable supports.
[0045] The reductive hydrogenation step is carried out under pressure, and generally at
elevated temperature. Usually a solvent is employed. This step can be carried out
by a batch, continuous or vapor-phase process. A continuous process is preferred.
The pressure is typically from 1 x 10
5 to 1 x 10
7 Pa, more preferably from 1 x 10
6 to 5 x 10
6 Pa. The temperature is generally from 150°C to 350°C, more preferably from 200°C
to 300°C. The time of reaction is generally from 30 minutes to 10 hours. Suitable
solvents include alcohols, particularly methanol, ethanol, propanol and butanol.
[0046] It is to appreciated that the exact process conditions used for any particular synthesis
will be varied to achieve optimum results in accord with the usual process optimization
steps which will be within the remit of the skilled person. In particular the process
conditions will be adjusted to minimise the occurrence of any competing side-reactions.
[0047] One possible problem derives from the incomplete reduction of the cyclic anhydride,
such that lactones are formed. These are however, convertible to diols by further
catalytic hydrogenation. It may be advantageous to carry out the hydrogenation in
two steps, preferably as part of a continuous step-wise process, such that a lactone
is formed in the first step followed by a second step in which the lactone is reduced
to the diol. Conditions which favour lactone formation are high temperature (∼300
°C) and low pressures (∼ 1 x 10
5 Pa). Any water formed during the hydrogenation will primarily be in the vapour phase,
so that the anhydride is unlikely to be converted into a carboxylic acid which can
inhibit the catalyst. The best conditions for diol formation from the lactone are
lower temperatures (∼220 °C) and high pressures (∼ 1 x 10
7 Pa), both of which conditions minimise the production of furan by-product.
[0048] Furans can be formed by a ring closure reaction of the diol product. The tendency
for such furans to form is greater at higher reaction temperatures and can be promoted
by the transition-metal containing catalysts employed in the reduction step. The formation
of furans may therefore be minimised by the use of lower reaction temperatures and
by designing the process such that once formed the diol is removed from the catalytic
environment. The latter objective is met by the use of a continuous process whereby
the reactants contact a high level of catalyst for a relatively short time and are
then removed from the catalytic environment. By optimization of the time of contact
with the catalyst the formation of the desired diol is maximised and that of the furan
by-product minimised.
[0049] The presence of acids promotes furan formation. In particular, carboxylic acids which
may be formed by certain ring-opening reactions of the cyclic anhydrides under the
conditions of the reduction step can promote furan formation. This problem can be
alleviated by first forming the lactone in a separate step as mentioned above or by
the use of an additional esterification step in which the cyclic anhydride is first
treated with an alcohol, particularly methanol, in the presence of an esterification
catalyst to form a diester. The diester is then converted to the diol via the reduction
step.
[0050] The sulfation step may be carried out using any of the sulfation steps known in the
art, including for example those described in US-A-3,634,269, US-A-3,959,334 and US-A-4,000,081.
In particular the sulfation may be carried out in two stages where the first stage
involves treatment of the diol with a sulfation agent, generally selected from the
group consisting of chlorosulfonic acid, sulfur trioxide, adducts of sulfur trioxide
with amines and any mixtures thereof. The second stage involves neutralization, which
is generally carried out using NaOH.
Synthesis Example I - C14 alkyl-1,4-disulfate
[0051] Decyl succinic anhydride as shown in the reaction scheme below (R = a heptyl group)
is employed as the starting material. This material is obtained by hydrogenation in
the presence of a Pd catalyst of the alkenyl succinic anhydride product obtained from
the 'ene' reaction of maleic (acid) anhydride with dec-1-ene.
[0052] The general reaction scheme for the reduction step is as outlined below:

[0053] It should be noted from the above that both furan and half ester by-products can
also be formed in the reaction. The reactor utilized is an electrically heated 500
ml (39 mm internal diameter x 432 mm internal length) Autoclave Engineers type 316
(tradename) stainless steel rocking autoclave fitted with an internal thermocouple
and valving for periodic sampling of reaction mixtures. The reactor is charged with
50 ml of alcohol solvent and 5 grams of copper chromite catalyst, as sold by Engelhardt
under the tradename CU-1885P, that had been washed several times with high purity
water, then several times with alcohol solvent. The reactor and contents are then
heated to 250°C at a hydrogen pressure of 2.4 x 10
6 Pa and held for 1 hour. The reactor is then cooled and charged (without exposing
the catalyst to air) with 20 grams of the cyclic anhydride starting material and an
additional 50 ml of alcohol solvent. The process is carried out under different conditions
of pressure and temperature, and with varying reaction times. Details of different
reaction conditions are summarised in the table below:
| Example No. |
Pressure (106Pa) |
Temp. (°C) |
Time |
Solvent |
| |
|
|
|
|
| 1 |
2.8 |
235 |
2.1 hr |
1-butanol |
| 2 |
2.1 |
210 |
48 hr |
1-butanol |
| 3 |
2.85 |
250 |
2.5 hr |
1-butanol |
| 4 |
2.1 |
250 |
15 hr |
methanol |
| 5 |
2.1 |
300 |
15 hr |
methanol |
| 6 |
2.1 |
200 |
15 hr |
1-octanol |
| 7 |
2.1 |
192 |
4.5 days |
isobutanol |
| 8 |
2.1 |
187 |
2.5 days |
ethylene glycol |
[0054] The sulfation step is carried out, in each case, on the 1,4-alkyl diol product obtained
from the reduction step. Chlorosulfonic acid is used which results in a high yield
(typically > 90%) of the required C
14 alkyl 1,4 disulfate end-product as shown below:

Synthesis Example II - C14 alkyl-1,4-disulfate
[0055] The alkenyl succinic anhydride product obtained from the 'ene' reaction of maleic
(acid) anhydride with dec-1-ene (i.e. R = a heptyl group) is used directly as the
cyclic anhydride starting material. The need for the additional 'pre-step' of reduction
of the alkenyl succinic anhydride to an alkyl succinic anhydride is thus avoided.
All other method steps are as in Synthesis Example I.
[0056] The reaction scheme for the reduction step is thus as shown below:

Synthesis Example III - Preparation of Alkyl 1,4-Sulfate/Sulfonates
[0057] 1,4-dialcohol starting materials are first prepared as described hereinbefore by
reduction of alkenyl succinic anhydrides. The desired compounds are then prepared
following the reaction sequence as follows (wherein R can be alkyl or alkenyl, C
8 to C
20):

[0058] This reaction scheme is described in part in greater detail in Berridge, et. al.,
(J. Org. Chem. 1990, 55, 1211). This paper illustrates Steps 1 and 2 for several 1,2-,
1,3-, and 1,4-dialcohols, and also illustrates the opening of cyclic sulfates with
phenoxide and fluoride anions. Thus, this reaction sequence is not limited to the
preparation of 1,4-sulfate/sulfonates, but may also be followed for the preparation
of 1,3-sulfate/sulfonates from the corresponding 1,3-dialcohols.
The alkoxylated dianionic cleaning agent
[0059] The alkoxylated dianionic cleaning agent to be used herein comprises a structural
skeleton of at least five carbon atoms, to which two anionic substituent groups spaced
at least three atoms apart are attached. At least one of said anionic substituent
groups is an alkoxy-linked sulfate group; the other is a sulfate or sulfonate group,
preferably a sulfate group linked by alkoxy moieties to the carbon structural skeleton.
Said structural skeleton can for example comprise any of the groups consisting of
alkyl, substituted alkyl, alkenyl, aryl, alkaryl, ether, ester, amine and amide groups.
Preferred alkoxy moieties are ethoxy, propoxy, and combinations thereof.
[0060] The structural skeleton preferably comprises from 5 to 32, preferably 7 to 28, most
preferably 12 to 24 atoms. Preferably the structural skeleton comprises only carbon-containing
groups and more preferably comprises only hydrocarbyl groups. Most preferably the
structural skeleton comprises only straight or branched chain alkyl groups.
[0061] The structural skeleton is preferably branched. Preferably at least 10 % by weight
of the structural skeleton is branched and the branches are preferably from 1 to 5,
more preferably from 1 to 3, most preferably from 1 to 2 atoms in length (not including
the sulfate or sulfonate group attached to the branching).
[0062] Again, the anionic substituent groups (which for purposes of counting positions along
the structural skeleton includes the alkoxy linking moieties) present in the alkoxylated
dianionic cleaning agents useful herein are spaced at a distance of at least three
atoms from each other. For example, where one anionic substituent group is attached
to a carbon (the first carbon), said first carbon is attached to a second carbon,
which is in turn, attached to a third carbon and the third carbon is attached to the
second anionic substituent group to give a spacing of three carbon atoms.
[0063] In a preferred aspect of the present invention, at least one alkoxy-linked anionic
substituent group is substituted at a primary position on the structural skeleton.
The anionic substituent groups are preferably spaced 1-3, 1-4, 1-5, 1-6 or greater
apart; a 1-4 substitution for disulfated compounds is most preferred. For full clarity,
the term 1-n substitution is to be interpreted such that 1 indicates an anionic substituent
group (including any alkoxy linking moieties) located at a given position on the structural
skeleton and n indicates the number of atoms spaced between the first and second anionic
substituent groups (including any alkoxy linking moieties).
[0064] A preferred alkoxylated dianionic cleaning agent has the formula

where R is an alkyl, substituted alkyl, alkenyl, aryl, alkaryl, ether, ester, amine
or amide group of chain length C
1 to C
28, preferably C
3 to C
24, most preferably C
8 to C
20, or hydrogen; A and B are independently selected from alkyl, substituted alkyl, and
alkenyl group of chain length C
1 to C
28, preferably C
1 to C
5, most preferably C
1 or C
2, or a covalent bond; EO/PO are alkoxy moieties selected from ethoxy, propoxy, and
mixed ethoxy/propoxy groups, wherein n and m are independently within the range of
from 0 to 10, with at least m or n being at least 1; A and B in total contain at least
2 atoms; A, B, and R in total contain from 4 to 31 carbon atoms; X and Y are anionic
groups selected from the group consisting of sulfate and sulfonate, provided that
at least one of X or Y is a sulfate group; and M is a cationic moiety, preferably
a substituted or unsubstituted ammonium ion, or an alkali or alkaline earth metal
ion.
[0065] The most preferred alkoxylated dianionic cleaning agent has the formula as above
where R is an alkyl group of chain length from C
10 to C
18, A and B are independently C
1 or C
2, n and m are both 1, both X and Y are sulfate groups, and M is a potassium, ammonium,
or a sodium ion.
[0066] The alkoxylated dianionic cleaning agent is typically present at levels of incorporation
of from 0.01% to 50%, preferably from 0.05% to 10%, more preferably from 0.1% to 5%,
and most preferably from 0.2% to 2% by weight of the soaking composition.
[0067] Preferred alkoxylated dianionic cleaning agents herein include ethoxylated and/or
propoxylated disulfate compounds, preferably C10-C24 straight or branched chain alkyl
or alkenyl ethoxylated and/or propoxylated disulfates, more preferably having the
formulae:

wherein R is a straight or branched chain alkyl or alkenyl group of chain length
from C6 to C
18; EO/PO are alkoxy moieties selected from ethoxy, propoxy, and mixed ethoxy/propoxy
groups; and n and m are independently within the range of from 0 to 10 (preferably
from 0 to 5), with at least m or n being 1.
[0068] As will be appreciated more fully from the following discussion of preferred synthesis
methods, the present invention compositions may also comprise some amount of sulfated
alcohols and/or sulfonated alcohols which may comprise (to differing degrees depending
on the reaction conditions used) a portion of the alkoxylated dianionic cleaning agent
raw material used to manufacture the present invention compositions. Such alcohols
are typically compatible with the present invention compositions and may be present
as long as the requisite amount of alkoxylated dianionic cleaning agent is present
in the final composition.
Synthesis Methods:
[0069] Known syntheses of certain disulfated surfactants, in general, use an alkyl or alkenyl
succinic anhydride as the principal starting material. This is initially subjected
to a reduction step from which a diol is obtained. Subsequently the diol is alkoxylated
and then subjected to a sulfation step to give the alkoxylated disulfated product.
As an example, US-A-3,832,408 and US-A-3,860,625 describe 2-alkyl or alkenyl-1,4-butanediol
ethoxylate disulfates prepared by the reduction of alkenyl succinic anhydrides with
lithium aluminum hydride to produce either alkenyl or alkyl diols which are then ethoxylated
prior to sulfation. See also US-A-3,634,269 describes 2-alkyl or alkenyl-1,4-butanediol
disulfates prepared by the reduction of alkenyl succinic anhydrides with lithium aluminum
hydride to produce either alkenyl or alkyl diols which are then sulfated. In addition,
US-A-3,959,334 and US-A-4,000,081 describe 2-hydrocarbyl-1,4-butanediol disulfates
also prepared using a method involving the reduction of alkenyl succinic anhydrides
with lithium aluminum hydride to produce either alkenyl or alkyl diols which are then
sulfated.
[0070] These compounds may also be made by a method involving synthesis of the disulfated
cleaning agent from a substituted cyclic anhydride having one or more carbon chain
substituents having in total at least 5 carbon atoms comprising the following steps:
(i) reduction of said substituted cyclic anhydride to form a diol;
(ii) alkoxylation of said diol to form an alkoxylated diol; and
(iii) sulfation of said alkoxylated diol to form a disulfate
wherein said reduction step comprises hydrogenation under pressure in the presence
of a transition metal-containing hydrogenation catalyst.
[0071] In this synthesis method of an alkoxylated dianionic cleaning agent herein the starting
material, i.e., said substituted cyclic anhydride, as well as the reduction of said
starting material to form a diol may be performed as for the synthesis method of a
dianionic cleaning agent described herein before.
[0072] Once obtained, the diol is then alkoxylated prior to the sulfation step, such that
alkoxylated disulfate cleaning agents are obtained as the final product. Suitable
methods for the alkoxylation of diols are described in US Patents 3,832,408 and 3,860,625
noted hereinbefore. The condensation products of the diols with from 1 to 25 moles,
preferably from 2 to 10 moles of alkylene oxide, particularly ethylene oxide and/or
propylene oxide, are preferred herein.
[0073] The sulfation step may be carried out using any of the sulfation steps known in the
art as already described hereinbefore in the synthesis method of the dianionic cleaning
agents herein.
Synthesis Example I - C14 alkyl-1,4-ethoxylate disulfate
[0074] Decyl succinic anhydride as shown in the reaction scheme below (R = a heptyl group)
is employed as the starting material. This material is obtained by hydrogenation in
the presence of a Pd catalyst of the alkenyl succinic anhydride product obtained from
the 'ene' reaction of maleic (acid) anhydride with dec-1-ene.
[0075] The general reaction scheme for the reduction step is as outlined below:

[0076] It should be noted from the above that both furan and half ester by-products can
also be formed in the reaction.
[0077] The reactor utilized is an electrically heated 500 ml (39 mm internal diameter x
432 mm internal length) Autoclave Engineers type 316 (tradename) stainless steel rocking
autoclave fitted with an internal thermocouple and valving for periodic sampling of
reaction mixtures. The reactor is charged with 50 ml of alcohol solvent and 5 grams
of copper chromite catalyst, as sold by Engelhardt under the tradename CU-1885P, that
had been washed several times with high purity water then several times with alcohol
solvent. The reactor and contents are then heated to 250°C at a hydrogen pressure
of 2.4 x 10
6 Pa and held for 1 hour. The reactor is then cooled and charged (without exposing
the catalyst to air) with 20 grams of the cyclic anhydride starting material and an
additional 50 ml of alcohol solvent. The process is carried out under different conditions
of pressure and temperature, and with varying reaction times. Details of different
reaction conditions are summarised in the table below:
| Example No. |
Pressure (106Pa) |
Temp. (°C) |
Time |
Solvent |
| |
|
|
|
|
| 1 |
2.8 |
235 |
2.1 hr |
1-butanol |
| 2 |
2.1 |
210 |
48 hr |
1-butanol |
| 3 |
2.85 |
250 |
2.5 hr |
1-butanol |
| 4 |
2.1 |
250 |
15 hr |
methanol |
| 5 |
2.1 |
300 |
15 hr |
methanol |
| 6 |
2.1 |
200 |
15 hr |
1-octanol |
| 7 |
2.1 |
192 |
4.5 days |
isobutanol |
| 8 |
2.1 |
187 |
2.5 days |
ethylene glycol |
[0078] This diol is then treated with an excess of ethylene oxide to give the ethoxylated
diol. The sulfation step is then carried out, in each case, on the 1,4-alkyl diol
product obtained from the reduction step. Chlorosulfonic acid is used which results
in a high yield (typically > 90%) of the required C
14 alkyl 1,4 ethoxylated disulfate end-product.
Synthesis Example II - C14 alkyl-1,4-ethoxylate disulfate
[0079] The alkenyl succinic anhydride product obtained from the 'ene' reaction of maleic
(acid) anhydride with dec-1-ene (i.e. R = a heptyl group) is used directly as the
cyclic anhydride starting material. The need for the additional 'pre-step' of reduction
of the alkenyl succinic anhydride to an alkyl succinic anhydride is thus avoided.
All other method steps are as in Synthesis Example I.
[0080] The reaction scheme for the reduction step is thus as shown below:

Optional ingredients:
[0081] As an optional but highly preferred ingredient, the compositions according to the
present invention may further comprise an oxygen bleach. Indeed, oxygen beaches provide
a multitude of benefits such as bleaching of stains, deodorization, as well as disinfectancy,
and the sorbitan esters and (alkoxylated) dianionic cleaning agents according to the
present invention have a further particular advantage that they are resistant to oxydation
by oxygen bleaches. The oxygen bleach in the composition may come from a variety of
sources such as hydrogen peroxide or any of the addition compounds of hydrogen peroxide,
or organic peroxyacid, or mixtures thereof. By addition compounds of hydrogen peroxide
it is meant compounds which are formed by the addition of hydrogen peroxide to a second
chemical compound, which may be for example an inorganic salt, urea or organic carboxylate,
to provide the addition compound. Examples of the addition compounds of hydrogen peroxide
include inorganic perhydrate salts, the compounds hydrogen peroxide forms with organic
carboxylates, urea, and compounds in which hydrogen peroxide is clathrated.
[0082] Other suitable oxygen beaches include persulphates, particularly potassium persulphate
K
2S
2O
8 and sodium persulphate Na
2S
2O
8. Examples of inorganic perhydrate salts include perborate, percarbonate, perphosphate
and persilicate salts. The inorganic perhydrate salts are normally the alkali metal
salts.
[0083] The alkali metal salt of percarbonate, perborate or mixtures thereof, are the preferred
inorganic perhydrate salts for use herein. Preferred alkali metal salt of percarbonate
is sodium percarbonate.
[0084] Soaking compositions in the present invention may comprise from 0.01% to 80% by weight
of the total composition of an oxygen bleach or mixtures thereof, preferably from
5% to 45% and more preferably from 10% to 40%.
[0085] When the soaking compositions herein comprise an oxygen bleach, it is preferred for
them to further comprise bleach activators typically up to a level of 30% by weight
of the total composition. Examples of suitable compounds of this type are disclosed
in British Patent GB 1 586 769 and GB 2 143 231. Preferred examples of such compounds
are tetracetyl ethylene diamine, (TAED), sodium 3, 5, 5 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), and acetyl triethyl citrate (ATC) such as described in European patent application
91870207.7. Also particularly preferred are N-acyl caprolactam selected from the group
consisting of substituted or unsubstituted benzoyl caprolactam, octanyl caprolactam,
nonanoyl caprolactam, hexanoyl caprolactam, decanoyl caprolactam, undecenoyl caprolactam,
formyl caprolactam, acetyl caprolactam, propanoyl caprolactam, butanoyl caprolactam
pentanoyl caprolactam. The soaking compositions herein may comprise mixtures of said
bleach activators.
[0086] Preferred mixtures of bleach activators herein comprise n-nonanoyloxybenzenesulphonate
(NOBS) together with a second bleach activator having a low tendency to generate diacyl
peroxide, but which delivers mainly peracid. Said second bleach activators may include
tetracetyl ethylene diamine (TAED), acetyl triethyl citrate (ATC), acetyl caprolactam,
benzoyl caprolactam and the like, or mixtures thereof. Indeed, it has been found that
mixtures of bleach activators comprising n-nonanoyloxybenzenesulphonate and said second
bleach activators, allow to boost particulate soil cleaning performance while exhibiting
at the same time good performance on diacyl peroxide sensitive soil (e.g. beta-carotene)
and on peracid sensitive soil (e.g. body soils).
[0087] Accordingly, the soaking compositions herein may comprise from 0% to 15% by weight
of the total composition of n-nonanoyloxybenzenesulphonate, preferably from 1% to
10% and more preferably from 3% to 7% and from 0% to 15% by weight of the total composition
of said second bleach activator preferably from 1% to 10% and more preferably from
3% to 7%.
[0088] The compositions herein may comprise an acidifying system amongst the preferred optional
ingredients. The purpose of said acidifying system is to control the alkalinity generated
by the source of available oxygen and any alkaline compounds present in the wash solution.
Said system comprises anhydrous acidifying agent, or mixtures thereof, which needs
to be incorporated in the product in an anhydrous form, and to have a good stability
in oxidizing environment. Suitable anhydrous acidifying agents for use herein are
carboxylic acids such as citric acid, adipic acid, glutaric acid, 3 chetoglutaric
acid, citramalic acid, tartaric acid and maleic acid or their salts or mixtures thereof.
Other suitable acidifying agents include sodium bicarbonate, sodium sesquicarbonate
and silicic acid. Highly preferred acidifying system to be used herein comprise citric
acid and/or sodium citrate. Indeed, citric acid can be used in its acidic form or
in the form of its salts (mono-, di-, tri- salts) and in all its anhydrous and hydrated
forms, or mixtures thereof. It may additionally act as a builder and a chelant, and
it is biodegradable. The compositions according to the present invention comprise
from up to 20% by weight of the total composition of anhydrous citric acid, preferably
from 5% to 15%, most preferably about 10%.
[0089] The compositions herein may comprise an alkali metal salt of silicate, or mixtures
thereof, amongst the preferred optional ingredients. Preferred alkali metal salt of
silicate to be used herein is sodium silicate. In the preferred embodiment herein
wherein the soaking compositions comprise an oxygen bleach, it has been found that
the decomposition of available oxygen produced in the soaking liquors upon dissolution
of the soaking compositions is reduced by the presence of at least 40 parts per million
of sodium silicate in said soaking liquors.
[0090] Any type of alkali metal salt of silicate can be used herein, including the crystalline
forms as well as the amorphous forms of said alkali metal salt of silicate or mixtures
thereof.
[0091] Suitable crystalline forms of sodium silicate to be used are the crystalline layered
silicates of the granular formula
NaMSi
xO
2x+1.yH
2O
wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from
0 to 20, or mixtures thereof. Crystalline layered sodium silicates of this type are
disclosed in EP-A-164 514 and methods for their preparation are disclosed in DE-A-34
17 649 and DE-A-37 42 043. For the purposes of the present invention, x in the general
formula above has a value of 2, 3 or 4 and is preferably 2. More preferably M is sodium
and y is 0 and preferred examples of this formula comprise the a , b , g and d forms
of Na
2Si
2O
5. These materials are available from Hoechst AG FRG as respectively NaSKS-5, NaSKS-7,
NaSKS-11 and NaSKS-6. The most preferred material is d - Na
2Si
2O
5, NaSKS-6. Crystalline layered silicates are incorporated in soaking compositions herein,
either as dry mixed solids, or as solid components of agglomerates with other components.
[0092] Suitable amorphous forms of sodium silicate to be used herein have the following
general formula:
NaMSi
xO
2x+1
wherein M is sodium or hydrogen and x is a number from 1.9 to 4, or mixtures thereof.
Preferred to be used herein are the amorphous forms of Si
2O
5 Na
2O.
[0093] Suitable Zeolites for use herein are aluminosilicates including those having the
empirical formula:
Mz(zAlO2.ySiO2)
wherein M is sodium, potassium, ammonium or substituted ammonium, z is from about
0.5 to about 2; and y is 1; this material having a magnesium ion exchange capacity
of at least about 50 milligram equivalents of CaCO3 hardness per gram of anhydrous
aluminosilicate. Preferred zeolites which have the formula:
Nazí(AlO2)z (SiO2)yù.xH2O
wherein z and y are integers of at least 6, the molar ratio of z to y is in the range
from 1.0 to about 0.5, and x is an integer from about 15 to about 264.
[0094] Useful materials are commercially available. These aluminosilicates can be crystalline
or amorphous in structure and can be naturally-occurring aluminosilicates or synthetically
derived. A method for producing aluminosilicate ion exchange materials is disclosed
in U.S. Patent 3,985,669, Krummel, et al, issued October 12, 1976. Preferred synthetic
crystalline aluminosilicate ion exchange materials useful herein are available under
the designations Zeolite A, Zeolite P (B), and Zeolite X. In an especially preferred
embodiment, the crystalline aluminosilicate ion exchange material has the formula:
Na12í(AlO2)12(SiO2)12ù.xH2O
wherein x is from 20 to 30, especially about 27. This material is known as Zeolite
A. Preferably, the aluminosilicate has a particle size of about 0.1-10 microns in
diameter.
[0095] Typically, the compositions herein may comprise from 0.5% to 15% by weight of the
total composition of an alkali metal salt of silicate or mixtures thereof, preferably
from 1% to 10% and more preferably from 2% to 7%.
[0096] The composition herein may also comprise a builder amongst the preferred optional
ingredients. All builders known to those skilled in the art may be used herein. Suitable
phosphate builders for use herein include sodium and potassium tripolyphosphate, pyrophosphate,
polymeric metaphosphate having a degree of polymerization of from about 6 to 21, and
orthophosphate. Other phosphorus builder compounds are disclosed in U.S. Pat. Nos.
3,159,581; 3,213,030; 3,422,021; 3,422,137; 3,400,176 and 3,400,148, incorporated
herein by reference.
[0097] Suitable polycarboxylate builders for use herein include ether polycarboxylates,
including oxydisuccinate, as disclosed in Berg, U.S. Patent 3,128,287, issued April
7, 1964, and Lamberti et al, U.S. Patent 3,635,830, issued January 18, 1972. See also
"TMS/TDS" builders of U.S. Patent 4,663,071, issued to Bush et al, on May 5, 1987.
Suitable ether polycarboxylates also include cyclic compounds, particularly alicyclic
compounds, such as those described in U.S. Patents 3,923,679; 3,835,163; 4,120,874
and 4,102,903.
[0098] Other useful detergency builders include the ether hydroxypolycarboxylates, 1,3,5-trihydroxy
benzene-2,4,6-trisulphonic acid, and carboxymethyloxysuccinic acid, the various alkali
metal, ammonium and substituted ammonium salts of polyacetic acids such as ethylenediamine
tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic
acid, succinic acid, oxydisuccinic acid, polymaleic acid, benzene 1,3,5-tricarboxylic
acid, carboxymethyloxysuccinic acid, and soluble salts thereof.
[0099] Also suitable in the detergent compositions of the present invention are the 3,3-dicarboxy-4-oxa-1,6-hexanedioates
and the related compounds disclosed in U.S. Patent 4,566,984, Bush, issued January
28, 1986. Useful succinic acid builders include the C
5-C
20 alkyl and alkenyl succinic acids and salts thereof. A particularly preferred compound
of this type is dodecenylsuccinic acid. Specific examples of succinate builders include:
laurylsuccinate, myristylsuccinate, palmitylsuccinate, 2-dodecenylsuccinate (preferred),
2-pentadecenylsuccinate, and the like. Laurylsuccinates are the preferred builders
of this group, and are described in European Patent Application 86200690.5/0,200,263,
published November 5, 1986.
[0100] Other suitable polycarboxylate builders are disclosed in U.S. Patent 4,144,226, Crutchfield
et al, issued March 13, 1979 and in U.S. Patent 3,308,067, Diehl, issued March 7,
1967. See also Diehl U.S. Patent 3,723,322.
[0101] Other suitable polycarboxylate buiders for use herein include builders according
to formula I

wherein Y is a comonomer or comonomer mixture; R
1 and R
2 are bleach- and alkali-stable polymer-end groups; R
3 is H, OH or C
1-4 alkyl; M is H, alkali metal, alkaline earth metal, ammonium or substituted ammonium;
p is from 0 to 2; and n is at least 10, or mixtures thereof.
[0102] Preferred polymers for use herein fall into two categories. The first category belongs
to the class of copolymeric polymers which are formed from an unsaturated polycarboxylic
acid such as maleic acid, citraconic acid, itaconic acid, mesaconic acid and salts
thereof as first monomer, and an unsaturated monocarboxylic acid such as acrylic acid
or an alpha -C
1-4 alkyl acrylic acid as second monomer. Referring to formula I hereinabove, the polymers
belonging to said first class are those where p is not 0 and Y is selected from the
acids listed hereinabove. Preferred polymers of this class are those according to
formula I hereinabove, where Y is maleic acid. Also, in a preferred embodiment, R
3 and M are H, and n is such that the polymers have a molecular weight of from 1000
to 400 000 atomic mass units.
[0103] The second category of preferred polymers for use herein belongs to the class of
polymers in which, referring to formula I hereinabove, p is 0 and R
3 is H or C
1-4 alkyl. In a preferred embodiment n is such that the polymers have a molecular weight
of from 1000 to 400 000 atomic mass units. In a highly preferred embodiment, R
3 and M are H.
[0104] The alkali-stable polymer end groups R
1 and R
2 in formula I hereinabove suitably include alkyl groups, oxyalkyl groups and alkyl
carboxylic acid groups and salts and esters thereof.
[0105] In the above, n, the degree of polymerization of the polymer can be determined from
the weight average polymer molecular weight by dividing the latter by the average
monomer molecular weight. Thus, for a maleic-acrylic copolymer having a weight average
molecular weight of 15,500 and comprising 30 mole % of maleic acid derived units,
n is 182 (i.e. 15,500 / (116 x 0.3 + 72 x 0.7)).
[0106] Temperature-controlled columns at 40°C against sodium polystyrene sulphonate polymer
standards, available from Polymer Laboratories Ltd., Shropshire, UK, the polymer standards
being 0.15M sodium dihydrogen phosphate and 0.02M tetramethyl ammonium hydroxide at
pH 7.0 in 80/20 water/acetonitrile.
[0107] Of all the above, highly preferred polymers for use herein are those of the first
category in which n averages from 100 to 800, preferably from 120 to 400.
[0108] Preferred builders for use herein are polymers of maleic or acrylic acid, or copolymers
of maleic and acrylic acid.
[0109] Typically, the compositions of the present invention comprise up to 50% by weight
of the total composition of a builder or mixtures thereof, preferably from 0.1% to
20% and more preferably from 0.5% to 10%.
[0110] The compositions according to the present invention may further comprise a soil suspending
polyamine polymer or mixtures thereof, as optional ingredient. 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 polyalkoxylated 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.
[0111] 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.
[0112] It has surprisingly been found that said soil suspending polyamine polymers contribute
to the benefits of the present invention, i.e., that when added in a soaking composition
comprising sorbitan ester and a dianionic cleaning agent and/or an alkoxylated dianionic
cleaning agent, they further improve the stain removal performance of said composition.
Indeed, they allow to improve the stain removal performance on a variety of stains
including particulate soils, enzymatic stains as well as greasy stains and/or bleachable
stains.
[0113] Typically, the compositions of the present invention comprise up to 10% by weight
of the total composition of such a soil suspending polyamine polymer or mixtures thereof,
preferably from 0.1% to 5% and more preferably from 0.3% to 2%.
[0114] When the soaking compositions herein comprise an oxygen bleach, it may be desirable
for them to further comprise chelating agents which help to control the level of free
heavy metal ions in the soaking liquors, thus avoiding rapid decomposition of the
oxygen released by said source of available oxygen. Suitable amino carboxylate cheating
agents which may be used herein include diethylene triamino pentacetic acid, ethylenediamine
tetraacetates (EDTA), N-hydroxyethylethylenediamine triacetates, nitrilotriacetates,
ethylenediamine tetraproprionates, triethylenetetraamine hexaacetates, and ethanoldiglycines,
alkali metal ammonium and substituted ammonium salts thereof or mixtures thereof.
Further suitable chelating agents include ethylenediamine-N,N'-disuccinic acids (EDDS)
or alkali metal, alkaline earth metal, ammonium, or substituted ammonium salts thereof.
Particularly suitable EDDS compounds are the free acid form and the sodium or magnesium
salt or complex thereof. Also other suitable chelating agents may be the organic phosphonates,
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 in the form of their metal alkali
salt. Preferably the organic phosphonate compounds where present are in the form of
their magnesium salt.
[0115] The soaking compositions in the present invention may accordingly comprise from 0%
to 5% by weight of the total compositions of said chelating agents, preferably from
0% to 3%, more preferably from 0.05% to 2%.
[0116] The compositions herein may further comprise a filler like inorganic filler salts
such as alkali metal carbonates, bicarbonates and sulphates. Such fillers, for instance
sodium bicarbonate, may also act as acidifying agent as described hereinbefore. Accordingly,
sodium bicarbonate and sodium sulphate are the preferred filler materials for use
herein.
[0117] Typically, the compositions of the present invention comprise up to 50% by weight
of the total composition of a filler or mixtures thereof, preferably from 0.1% to
15 % and more preferably from 1% to 6%.
[0118] Soaking compositions in the present invention may further comprise other optional
ingredients such as surfactants, optical brighteners, enzymes, other chelants, dispersants,
soil release agents, photoactivated bleaches such as Zn phthalocyanine sulphonate,
dyes, dye transfer inhibitors, pigments, perfumes and the like. Said optional ingredients
can be added in varying amounts as desired.
[0119] The compositions herein can be manufactured in solid, preferably granular, or even
in liquid form.
B - The process:
[0120] The present invention encompasses processes of soaking fabrics. Indeed, the present
invention encompasses a process of soaking fabrics, wherein said fabrics are immersed
in a soaking liquor comprising water and an effective amount of a composition as described
hereinbefore, for an effective period of time, then removed from said soaking liquor.
[0121] As used herein, the expression "process of soaking fabrics" refers to the action
of leaving fabrics to soak in a soaking liquor comprising water and a composition
as described hereinabove, for a period of time sufficient to clean said fabrics. In
contrast to typical laundering operation using a washing machine, the soaking process
herein allows prolonged contact time between the fabrics and the soaking liquor, typically
up to 24 hours. The soaking process can be performed independently from any other
process, such as a typical laundering operation, or a first step before a second,
typical laundering step. In the preferred soaking processes of the invention, fabrics
are left to soak for a period of time ranging from 10 minutes to 24 hours, preferably
from 30 min to 24 hours, more preferably more than 1 hour to 24 hours, even more preferable
2 hours to 24 hours, and most preferably 4 hours to 24 hours. After the fabrics have
been immersed in said soaking liquor for a sufficient period of time, they can be
removed and rinsed with water. The fabrics can also be washed in a normal laundering
operation after they have been soaked, with or without having been rinsed in between
the soaking operation and the subsequent laundering operation.
[0122] In the soaking process herein, a soaking composition described hereinabove is diluted
in an appropriate amount of water to produce a soaking liquor. Suitable doses may
range from 45 to 50 grams of soaking composition in 3.5 to 5 liters of water, down
to 90 to 100 grams of soaking composition in 20 to 45 liters of water. Typically one
dose is 45-50 grams in 3.5 to 5 liters for a concentrated soak (bucket/sink). For
washing machine soaked, the dose is 90-100 grams in about 20 (Europe) to 45 (US) liters
of water. The fabrics to be soaked are then immersed in the soaking liquor for an
appropriate period of time. There are factors which may influence overall performance
of the process on particulate dirt/soils. Such factors include prolonged soaking time.
Indeed, the longer fabrics are soaked, the better the end results. Ideally, soaking
time is overnight, i.e., 8 hours up to 24 hours, preferably 12 hours to 24 hours.
Another factor is the initial warm or warmluke temperature. Indeed, higher initial
temperatures of the soaking liquors ensure large benefits in performance.
[0123] The process herein is suitable for cleaning a variety of fabrics, but finds a preferred
application in the soaking of socks, which are particularly exposed to silt and clay
pick-up.
[0124] In its broadest embodiment the present invention also encompasses a process of soaking
fabrics, wherein said fabrics are immersed in a soaking liquor comprising water and
an effective amount of a composition comprising a dianionic cleaning agent, as defined
herein, and/or an alkoxylated dianionic cleaning agent, as defined herein, for more
than 1 hour, preferably more than 2 hours and more preferably 4 hours to 24 hours,
then removed from said soaking liquor. Indeed, it has been found that when adding
such a dianionic cleaning agent and/or an alkoxylated dianionic cleaning agent, in
a soaking composition, improved particulate soil removal and/or improved enzymatic
stain removal is obtained.
The stain removal performance test method:
[0125] The stain removal performance of a given composition on a soiled fabric under soaking
conditions, may be evaluated by the following test method. Soaking liquors are formed
by diluting for instance 45 g of the soaking compositions herein in 3.78 liters of
water or 90 g of the soaking composition in 45 liters of water. Fabrics are then immersed
in the resulting soaking liquor for a time ranging from 30 minutes to 18 hours. Finally,
the fabrics are removed from the soaking liquors, rinsed with water and washed with
a regular washing process, handwash or washing machine wash, with a regular detergent,
with or without re-using the soaking liquor, then said fabrics are left to dry.
[0126] For example, typical soiled fabrics to be used in this stain removal performance
test may be commercially available from EMC (Empirical Manufacturing Company) Cincinnati,
Ohio, USA, such as clay, grass, spaghetti sauce, gravy, dirty motor oil, make-up,
barbecue sauce, tea, blood on two different substrates: cotton (CW120) and polycotton
(PCW28).
[0127] The stain removal performance may be evaluated by comparing side by side the soiled
fabrics pretreated with the composition according to the present invention with those
pretreated with the reference, e.g., the same composition without such a dianionic
cleaning agent or alkoxylated dianionic cleaning agent according to the present invention.
A visual grading scale may be used to assign differences in panel score units (psu),
in a range from 0 to 4.
[0128] The following examples will further illustrate the present invention.
Examples
[0129] The following compositions are prepared by mixing the listed ingredients in the listed
proportions.
| Ingredients |
1 (%w/w) |
2 (%w/w) |
3 (%w/w) |
| Sorbitan mono-stearate (SMS) |
0.5 |
0.5 |
0.5 |
| Citric acid |
11 |
11 |
11 |
| NOBS |
12 |
12 |
12 |
| Polyacrylate (Acusol 445ND) |
11 |
11 |
11 |
| Sodium percarbonate |
31 |
31 |
31 |
| 2-dodecyl 1,4- butane disulphate |
0.7 |
- |
- |
| 2-hexadecyl 1,4 butane disulphate |
- |
0.7 |
- |
| 2-octadecyl 1,4 butane disulphate |
- |
- |
0.7 |
| Anionic (LAS/AS/AES) |
8 |
8 |
8 |
| DTPA |
0.2 |
0.2 |
0.2 |
| Others, Inerts and minors |
up to 100 |
up to 100 |
up to 100 |
| Ingredients |
4 (%w/w) |
5 (%w/w) |
6 (%w/w) |
| Sorbitan mono-stearate (SMS) |
0.5 |
0.5 |
0.5 |
| Citric acid |
11 |
11 |
11 |
| NOBS |
12 |
12 |
12 |
| Polyacrylate (Acusol 445ND) |
11 |
11 |
11 |
| Sodium percarbonate |
31 |
31 |
31 |
| 2-C14 1,4- butane disulphate |
0.7 |
- |
- |
| 2-decyl 1,4 butane disulphate |
- |
0.7 |
- |
| 2-octyl 1,4 butane disulphate |
- |
- |
0.7 |
| Anionic (LAS/AS/AES) |
8 |
8 |
8 |
| DTPA |
0.2 |
0.2 |
0.2 |
| Others, inerts and minors |
up to 100 |
up to 100 |
up to 100 |
| Ingredients |
7 (%w/w) |
8 (%w/w) |
9 (%w/w) |
| Sorbitan mono-stearate (SMS) |
2.50 |
0 |
0 |
| Sorbitan monostearate EO 20 (SMS EO 20) |
0 |
3.00 |
0 |
| Sorbitan tristearate EO 20 (STS EO 20) |
0.50 |
0 |
3.00 |
| Citric acid |
10 |
10 |
10 |
| Blend of 1,4-disulphates (C18-C22) |
1 |
1 |
1 |
| Polyacrylate (Acusol 445 ND) |
11 |
11 |
11 |
| Silicate (amorphous; 1.6r) |
0.4 |
0.4 |
0.4 |
| Sodium perborate monohydrate |
0 |
0 |
0 |
| Sodium percarbonate |
31 |
31 |
31 |
| Sodium sulphate |
24 |
24 |
24 |
| NOBS |
6 |
6 |
6 |
| TAED |
5 |
5 |
5 |
| Anionic (LAS/AS/AES) |
7 |
7 |
7 |
| Others, inerts and minors |
up to 100 |
up to 100 |
up to 100 |
| Ingredients |
10 (%w/w) |
11 (%w/w) |
12 (%w/w) |
| Sorbitan mono-stearate (SMS) |
0.5 |
0.5 |
0.5 |
| Citric acid |
11 |
11 |
11 |
| NOBS |
12 |
12 |
12 |
| Polyacrylate (Acusol 445ND) |
11 |
11 |
11 |
| Sodium percarbonate |
31 |
31 |
31 |
| C16 alkyl 1,4 ethoxylated disulphate |
2.0 |
0 |
0 |
| C14 alkyl 1,4 ethoxylated disulphate |
0 |
2.0 |
0 |
| C18 alkyl 1,4 ethoxylated disulphate |
0 |
0 |
2.0 |
| Anionic (LAS/AS/AES) |
8 |
8 |
8 |
| DTPA |
0.2 |
0.2 |
0.2 |
| Others, inerts and minors |
up to 100 |
up to 100 |
up to 100 |
[0130] Soaking liquors are formed by diluting 45 g of each of the above compositions 1 to
12 in between 3.5 lit. to 5.0 lit. of water. 0.5 to 2 Kg of fabrics are then each
time immersed in said soaking liquors for a time ranging from 10 minutes to 24 hours.
Finally, the fabrics are removed from the soaking liquors, rinsed with water and washed
with a regular washing process, handwash or washing machine wash, with a regular detergent,
with or without re-using the soaking liquor, then said fabrics are left to dry. Excellent
stain removal performance is obtained with these compositions on various stains including
mud/clay stains, enzymatic stains, greasy stains, bleachable stains and the like.
| Ingredients |
13 (%w/w) |
14 (%w/w) |
15 (%w/w) |
| Citric acid |
11 |
11 |
11 |
| NOBS |
12 |
12 |
12 |
| Polyacrylate (Acusol 445ND) |
11 |
11 |
11 |
| Sodium percarbonate |
31 |
31 |
31 |
| 2-C14 1,4- butane disulphate |
0.7 |
- |
- |
| 2-decyl 1,4 butane disulphate |
- |
0.7 |
- |
| 2-octyl 1,4 butane disulphate |
- |
- |
0.7 |
| Anionic (LAS/AS/AES) |
8 |
8 |
8 |
| DTPA |
0.2 |
0.2 |
0.2 |
| Others, inerts and minors |
up to 100 |
up to 100 |
up to 100 |
[0131] Soaking liquors are formed by diluting 45 g of each of the above compositions 13
to 15 in between 3.5 lit. to 5.0 lit. of water. 0.5 to 2 Kg of fabrics are then each
time immersed in said soaking liquors for more than 1 hour, typically 4 hours to 24
hours. Finally, the fabrics are removed from the soaking liquors, rinsed with water
and washed with a regular washing process, handwash or washing machine wash, with
a regular detergent, with or without re-using the soaking liquor, then said fabrics
are left to dry. Good stain removal performance is obtained with these processes on
various stains including mud/clay stains, enzymatic stains, greasy stains, bleachable
stains and the like.