[0001] The present invention relates to aqueous compositions of acids or acidic salts and
more particularly to novel compositions of these acids or acidic salts which include
a thickening agent.
[0002] As used in the specification acidic salts refer to those compounds which in an aqueous
solution liberate protons.
[0003] Aqueous solutions of acids and acidic salts have long been used in compositions for
cleaning. Such compositions include toilet bowl cleaners, metal cleaners and brighteners,
rust stain removers, denture cleansers, metal descalers, general hard surface cleaners
and disinfectants.
[0004] It has been found that a desirable property of many of the aforementioned compositions
is that they have sufficient viscosity so as to allow the composition to be effectively
applied to surfaces, for example, by brushing, or to allow the composition to remain
in contact with the surface for a sufficient time to act. The latter function has
particular relevance to the cleaning of angular surfaces such as those found in toilet
bowls where prolonged contact between the composition and the bowl is required for
effective cleaning.
[0005] There are many such compositions known in the art that have the requisite viscosity
characteristics. Most of such compositions achieve their viscosity through the use
of one or more of the following thickening agents:-
(a) cellulose derivatives exemplified by sodium carboxymethyl cellulose, hydroxyethyl
cellulose, methyl hydroxyethyl cellulose, methyl cellulose, hydroxypropylmethyl cellulose,
hydroxybutylmethyl cellulose;
(b) gums such as xanthan gum,
(c) acrylic acid polymers such as Carbopol (Registered Trade Mark of B.F. Goodrich)
(d) nonionic surfactants such as nonyl phenol ethoxylates;
(e) poly(ethylene oxide) resins such as Polyox (Registered Trade Mark of Union Carbide);
(f) anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates;
and
(g) sodium silicates such as sodium metasilicate.
[0006] Most of these thickeners whilst able to effectively increase the viscosity of aqueous
acid or acidic salt compositions do have some disadvantages in use.
[0007] The cellulose derivatives and gums tend to hydrolyse on storage which results in
a reduction in viscosity of the composition. They are also generally difficult to
dissolve, in some cases intensive mixing being required in order to bring them into
solution.
[0008] Acrylic acid polymers are generally only useful in solutions which have a pH near
neutral and above. They also tend to hydrolyse on storage and to achieve viscosity,
need to be neutralized with a fairly strong alkali.
[0009] Nonionic surfactants have the disadvantage that usually high levels of about 5-10
0/o are required to achieve satisfactory viscosity, thus making them expensive to use.
[0010] The poly(ethyleneoxide) water soluble resins also require generally high levels to
achieve desirable composition viscosity and additionally, in some acid solutions show
significant instability.
[0011] Sodium silicates are able to produce aqueous acid or acidic salt gel compositions.
However, in developing viscosity in a composition, it has been noted that the viscosity
generally develops over a long period of time, for example, as much as twelve hours.
In commercial manufacturing processes, this is often inconvenient. It is also to be
noted that on storage, such gels tend to break down into small pieces which in many
instances is undesirable.
[0012] Other thickening agents and compositions disclosed in the art which relate to an
aqueous acid and/or acidic salt compositions include:-
GB1,443,244 (Reckitt & Colman Products Limited) which discloses a thickening agent
of the formula:

for thickening aqueous compositions of mineral acids and acid salts of strong inorganic
acids.
GB2,071,688 (Jeyes Limited) which discloses as a thickening agent a mixture of: (a)
a substantially acid insoluble compound of the formula (I) or (11); and
(b) a substantially acid soluble cationic or nonionic surfactant, for thickening aqueous
compositions of inorganic acids or acid salts of strong inorganic acids.


[0013] US 3,786,091 (Bolsing) which discloses a phosphoric acid containing base paste, produced
by preparing a finely divided aqueous dispersion of a long chain amine, preheating
this dispersion, introducing preheated phosphoric acid thereinto with vigorous agitation,
at elevated temperature until neutral and then stirring the resulting mixture until
cold.
[0014] US 4,021,377 (Borchert et al) which discloses a citric acid-amine reaction product
obtained by mixing citric acid and water soluble or water dispersible amine in water
until all the citric acid is dissolved. Generally the reaction is accompanied by a
rise in temperature to about 40° C over an hour. The resultant solution containing
amine salts of citric acid and citric acid amides is viscous. It is to be noted that
the concentrations of citric acid and the amines exemplified are particularly high,
the amines exemplified being in the range 12-4.5% W/W and the citric acid, 19.2% W/W.
Further, only the amines monoethanolamine, diethanolamine and triethanolamine are
exemplified.
[0015] The present inventor has recognized the difficulties of the prior art thickening
agents for such aqueous acid or acidic salt compositions. Accordingly, the present
invention seeks to provide alternative compositions to those of the prior art.
[0016] The present invention consists in a thickened aqueous composition comprising at least
one compound selected from the group consisting of acids and acidic salts, a thickening
agent which is at least one of the compounds selected from the group consisting of
compounds of the formula:

in which R, R
3 is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
R
1 is hydrogen, a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl
group, R
2 is hydrogen, a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl
group, R
4 is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
Rs is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
or R
1 and R
2 or R
4 and Rs when taken together comprise a substituted or unsubstituted heterocyclic ring,
provided that if either R, R
1 or R
2 is an alkyl or alkenyl group derived from a fatty acid obtained from a natural oil
or fat or an equivalent synthetic fatty acid, or is an alkaryl group containing from
8 to 12 carbon atoms in the alkyl moiety, then the other substituents are not respectively
of the formulae: [A]
x - H and [A]y - H where A is either ethoxy or propoxy and x, y are independently 1,
2 or 3, and optionally a strong ionic salt, said thickening agent and the at least
one compound selected from the group consisting of acids and acidic salts being together
substantially water soluble, and wherein
said thickened aqueous composition has a viscosity of not less than 30 centipoise
at 25°C when measured with a Brookfield RVT viscometer at 50 rpm using a No. 1 spindle.
[0017] In a second aspect, the present invention consists in a method of forming a thickened
aqueous solution, comprising dissolving in water (a) at least one compound selected
from the group consisting of acids and acidic salts (b) a thickening agent which is
at least one of the compounds selected from the group consisting of compounds of the
formula:

in which R, Rs is a substituted or an unsubstituted alkyl, aryl, alkaryl, aralkyl
or alkenyl group, R
1 is hydrogen, a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl
group, R
2 is hydrogen, a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl
group, R
4 is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
R
5 is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
or R
1 and R
2, or R
4 and Rs when taken together comprise a substituted or unsubstituted heterocyclic ring,
provided that if either R, R
1 or R
2 is an alkyl or alkenyl group derived from a fatty acid obtained from a natural oil
or fat or an equivalent synthetic fatty acid, or is an alkaryl group containing from
8 to 12 carbon atoms in the alkyl moiety, then the other substituted are not respectively
of the formulae:
[A]x-H and [A]y-H where A is either ethoxy or propoxy and X, Y are independently 1,
2 or 3, and optionally (c) a strong ionic salt, said thickening agent and the at least
one compound selected from the group consisting of acids and acidic salts being together
substantially water soluble, in amounts sufficient to produce a viscosity of not less
than 30 centipoise at 25° C when measured with a Brookfield RVT viscometer at 50 rpm
using a No. spindle.
[0018] In the context of this specification, substantially water soluble means that a thickening
agent and an acid or acidic salt selected in accordance with the invention, will together
either be soluble in water at 25° C or at most will form a hazy soluble that does
not separate into two phases during normal storage.
[0019] It will be appreciated that the compositions of the present invention may be readily
distinguished over those disclosed in the aforementioned patent application GB2071688
(Jeyes Limited) in that the compositions claimed therein are directed towards substantially
acid insoluble amines or amine oxides, which require a substantially acid soluble
cationic or nonionic surfactant to achieve thickening.
[0020] By contrast the present invention is limited to either amines or amine oxides which
together with the selected acid or acidic salt are substantially water soluble, without
a cationic or nonionic surfactant being required in the case of the amines to achieve
solution and thickening, and in the case of the amine oxides, without the use of a
cationic, nonionic or anionic surfactant, particulary an alkyl sulphate to achieve
solution and thickening. It is also to be noted that in GB2071688 it is stated that
neither of the amine, amine oxide, cationic surfactant or nonionic surfactant alone
with an aqueous solution of an inorganic acid or acid salt will cause thickening.
[0021] It will also be appreciated that the aforementioned US 4,021,377 (Borchert et al)
does not disclose, nor does it suggest that thickening will occur in compositions
envisaged by the present invention without recourse to heating the amine with citric
acid to form various reaction products. The present inventor believes that the disclosure
in this US patent that the reaction products of citric acid and an amine are viscous
in solution was merely an observation by the inventors, and perhaps not unexpected
in view of the high concentration of reactants employed. In fact, there is no disclosure
in this US patent that the inventors are aware that levels of amines as low as those
preferred and exemplified in the present invention will form thickened compositions
with acid or acidic salt solutions. The real thrust of this patent is a method of
producing a concentrated solution of desired reaction products which happen in this
high concentration to be viscous.
[0022] In order to demonstrate this, the present inventor produced aqueous solutions containing
5010 w/w citric acid anhydrous and 20/o w/w mono-, di- or tri-ethanolamine. No thickening
was noted in any of these solutions. Similarly, in US 3,786,091 (Bolsing), it is taught
that it is necessary to obtain the reaction products between the selected amine and
phosphoric acid by heating them together to produce a paste.
[0023] Thus, Bolsing in the simplest embodiment of his invention disperses the selected
amine in water, heats the dispersion to between 40°C and 100°C and then adds to it
at least a neutralising amount of phosphoric acid, preheated to between 40°C and 120°C.
Stirring is continued until the temperature falls to between 5°C and 25° C and the
resultant composition is a paste consisting of the reaction products between phosphoric
acid and selected amine. Bolsing also discloses that other acids such as sulphuric,
hydrochloric, tartaric, oxalic, hydrofluoric and nitric may be used as an additive
to a base paste of his invention. He further discloses that other amines may also
be used as additives.
[0024] The present invention may be distinguished over Bolsing when it is considered that
the amines of the Bolsing invention must be derivatives of substituted or unsubstituted
hydrocarbons having 8-24 carbon atoms, the selected amine must be reacted by heating
with phosphoric acid to achieve viscosity and there is no hint or suggestion that
acids other than phosphoric acid are operative. Additionally, with respect to acidic
salts, it is noted that Bolsing refers to ammonium chloride as an auxilliary.
[0025] In contrast, the present invention teaches that thickening can be achieved with a
range of acids and acidic salts, no heating is required to obtain thickening and the
present inventor believes that amines additional to those of Bolsing are operative.
[0026] It is preferred that in the above formulae I or II, either of the groups R or R
s contains at least six carbon atoms. More preferably, either of the groups R or R
3 contains from 8 to 24 carbon atoms. Most preferably either of the groups R or R
3 contains from 8 to 24 carbon atoms in an unsubstituted alkyl or alkenyl group. Preferably,
the groups R
1 and R
2 are independently a hydrogen atom or a lower unsubstituted alkyl group, where lower
refers to groups containing 1 to 4 carbon atoms or a substituted alkyl group. More
preferably the groups R
i and R
2 are independently a hydrogen atom or a lower unsubstituted alkyl group. Most preferably,
the groups R
1 and R
2 are independently a hydrogen atom or a methyl group.
[0027] Preferably, the groups R
4 and Rs are independently a lower unsubstituted alkyl group, where lower refers to
groups containing 1 to 4 carbon atoms or a substituted alkyl group. More preferably,
the groups R
4 and Rs are independently a lower substituted or unsubstituted alkyl group. Most preferably
the groups R
4 and Rs are independently a methyl, or hydroxyethyl, or hydroxy propyl group.
[0028] Preferred thickening agents of the present invention that are primary amines include
Farmin O (Farmin is a registered trade mark of Kao Soap Co.) or Genamin OL-100D (Genamin
is a registered trade mark of Hoechst), both of which are mainly oleylamine and Farmin
T or Genamin TA100D, both of which are tallow fatty amine distilled. These thickening
agents are able to thicken organic acids including formic, acetic, DL lactic, adipic,
glycollic, malonic, succinic, pentetic, ascorbic, chloroacetic, citric and propionic
acids. In some cases a small addition of a strong ionic salt such as sodium chloride
is required to achieve adequate composition viscosity in the preferred concentration
range of thickening agent. Naturally, increasing the concentration of thickening agent
will increase viscosity in many cases. However, because of the relatively low cost
of such salts, it is preferred to use a mixture of thickening agent and strong ionic
salt to achieve the desired viscosity. However, it must also be considered that the
addition of extra thickening agent may increase the pH and thereby decrease the efficiency
of a composition.
[0029] Preferred thickening agents of the present invention that are tertiary amines include
Genamin S0302D (dimethyl soya bean oil fatty amine distilled) and Genamin TA302D (dimethyl
tallow fatty amine distilled). These amines are able to thicken organic acids including
citric acid, L tartaric acid, formic acid, DL malic acid, acetic acid, DL lactic acid,
adipic acid, maleic acid, ethylenediaminetetraacetic acid, glycollic, malonic, succinic
and propionic acid and inorganic acids including sulfamic acid, phosphoric acid, boric,
hydrofluoric and sulphuric acid. Generally, for reasons outlined above, these amines
require the addition of a strong ionic salt, such as sodium chloride in order to achieve
adequate composition viscosity in the preferred concentration range of thickening
agent.
[0030] Preferred thickening agents of the present invention that are tertiary amines able
to thicken acidic salts include Genamin TA302D and Genamin S0302D. Genamin TA302D
is able to thicken aqueous solutions of monosodium citrate, and potassium hydrogen
tartrate with the addition of a strong ionic salt such as sodium chloride. Genamin
S0302D is able to thicken aqueous solutions of aluminium sulphate, sodium hydrogen
sulphate, sodium dihydrogen orthophosphate, disodium ethylenediaminetetraacetate and
aluminium potassium sulphate with a small addition of a strong ionic salt such as
sodium chloride required in some cases; the sodium chloride being required to achieve
adequate composition viscosity as previously described.
[0031] Preferred thickening agents of the present invention that are primary amines able
to thicken acidic salts include farmin O, genamin OL-100D, Farmin T and Genamin TA-100D.
These amines are able to thicken aqueous solutions of aluminium acetate.
[0032] Other amines considered by the present inventor to be within the scope of this invention
include:
Farmin DMON (Dimethyl oleylamine),
Kao-DBA (dimethyl benzylamine) ;
N-lauryl morpholine;
N-Coco morpholine;
N-cetylmorpholine; and
Onamin 1416 (N-alkyl C14-CI6 dimethylamine)
Genamin 14R302D (tetradecyl dimethylamine distilled);
Genamin 16R302D (hexadecyl dimethylamine distilled);
Genamin 14R100D tetradecylamine distilled);
Genamin 16R100D (hexadecylamine distilled);
The following amines obtainable from KenoGard-
Amine 2MOL (dimethyloleylamine)
Amine 28 (dioctylamine)
Amine 210 (didecylamine)
Amine M28 (methyldioctylamine) and
Amine M210 (methyldidecylamine).
[0033] It is to be noted that the abovementioned preferred amines are in fact mixtures of
a number of amines with one amine being predominant. The present inventor believes
that the predominant amine may function to solubilize the minor amines in compositions
of the present invention.
[0034] For example, Farmin O is predominantly oleylamine having an approximate alkyl content
of 6% C
14, 13% C
16 and 81% C
18, whilst Genamin S0302D has an approximate average chain length distribution of 2%
C
14, 15% C
16 and 83% C
18 and Genamin TA302D has an approximate average chain length distribution of 5% C
14, 30% C16 and 65% Cis.
[0035] Preferred thickening agents of the present invention that are amine oxides include
Aromox T/12 (bis[2-hydroxyethyl]tallow amine oxide) and Ammonyx MCO (mixture of myristyl
and cetyl dimethyl amine oxides). Aromox is a trade mark of Armour Hess and Ammonyx
is a trade mark of Onyx Chemicals Co. Aromox T/12 is able to thicken citric, phosphoric
and sulphuric acids.
[0036] An example of a composition containing Ammonyx MCO was prepared to contain:
Ammonyx MCO (30% active) 6.67%
Sulphuric acid 3.83% w/w
Sodium chloride 0.7% w/w
Water 88.8% w/w
[0037] It was observed that whilst the viscosity was not determined, it appeared to be thick
and viscous. Futhermore, it is to be noted that whilst Ammonyx MCO water soluble,
its viscosity is water thin, even in a 6.67% aqueous solution additionally containing
solely 2% sodium chloride.
[0038] As in the case of the amines of the invention, the preferred amine oxides falling
within the scope of this invention are mixtures of amine oxides. Thus, AromoxT/12
has an average chain length distribution of 1% C
12, 3% C
14, 27% C
16, 24
0/
0 C
18, 1% C
14 (unsat), 40/0 C
16 (unsat) 39% C
18 (unsat), 1% C
18 (double unsat). Similarly, the amine oxides of the invention, may require a small
addition of a strong ionic salt to achieve adequate composition viscosity, as previously
described.
[0039] Other amine oxides considered by the present inventor to be within the scope of this
invention include:
bis (2-hydroxy ethyl) soya bean oil amine oxide;
dimethyl tallow amine oxide;
dimethyl oleyl amine oxide;
dimethyl soya bean oil amine oxide;
bis (2-hydroxy ethyl) oleyl amine oxide.
[0040] Additionally, amines or amine oxides of the invention may be generally derived from
natural or synthetic sources of tallow, soya bean oil, oleic acid, palmitic acid,
myristic acid, linoleic acid, linolenic acid, ricinoleic acid or hexadecanoic acid.
[0041] Generally the acids to which the present invention is directed include inorganic
acids such as sulphuric hydrofluoric, boric, sulphamic and phosphoric acids and the
organic acids Formic, acetic, DL lactic, propionic, citric, DL malic, L tartaric,
adipic, maleic and ethylenediaminetetraacetic acid, malonic, glycollic, succinic,
ascorbic, pentetic and chloroacetic acids.
[0042] The acidic salts to which the present invention is directed include the acid salts
of inorganic or organic acids such as monosodium citrate, sodium hydrogen sulphate,
sodium dihydrogen orthophosphate, disodium ethylenediaminetetraacetate, aluminium
acetate and potassium hydrogen tartrate, aluminium sulphate and aluminium potassium
sulphate.
[0043] The concentration of acid or acidic salt may be varied over a wide range depending
on the end use of the composition. In some cases, particularly where a strong acid
such as hydrofluoric acid is used and a near neutral product is required, the concentration
of acid or acidic salt may be as low as 0.01% w/w.
[0044] In other cases, the concentration of acid or acidic salt may be in excess of 90%.
[0045] Generally, the concentration of acid or acidic salt will lie in the range of from
0.1 to 30% w/w.
[0046] In use, generally the thickening agent will be present in a concentration in the
composition of from 0.1 to 10% w/w. Preferably, the concentration in the composition
will lie in the range of from 0.4 to 5.0% w/w. In order to achieve a desired viscosity
in the composition, the concentration of the thickening agent may be varied appropriately.
However, in some cases, it has been found that it is not possible to achieve sufficient
composition viscosity for some applications. In such cases, the addition of a salt
which has high ionic strength has been found to enhance the viscosity of these compositions.
In most cases however, the concentration of thickening agent and high ionic strength
salt will be optimized in order to produce a cost effective composition of the desired
viscosity. Generally, the ionic salts will be selected from alkali metal halides or
sulphates and ammonium halides or sulphates. Suitable such salts include sodium chloride,
sodium sulphate, potassium sulphate, potassium chloride, ammonium chloride and the
like.
[0047] Alternatively, the present inventor believes that certain long chain quaternary ammonium
compounds may achieve similar thickening to the aforementioned salts. An example is
Arquad 16-50 which is hexadecyltri- methyl ammonium chloride or Arquad S-50 which
is a mixture of octadecanyl and octadecadienyl trimethyl ammonium chloride. Arquad
is a trade mark of Armour Hess Chemicals.
[0048] It has further been found that in some cases whilst the composition is thick, clear
and stable at room temperature, in order to achieve a satisfactory upper and lower
cloud point for a composition, it is necessary to add another ingredient such as salt
with a strong ionic effect of the type mentioned above, a cationic, nonionic or amphoteric
surfactant or a solvent miscible with the composition, for example ethanol, isopropanol
butyl lcinol and the like (Icionol is a trade mark of ICI) and Dowanol DPM (dipropyleneglycol
methylether. Dowanol is a trade mark of Dow Chemicals). Such an addition of salt,
surfactant or solvent insures that a composition will remain stable under hot and
cold weather conditions.
[0049] A variety of other ingredients may be added to compositions of the invention depending
on their end use. Thus, germicides, surfactants including anionic, nonionic, cationic
and amphoteric, sequestering agents, corrosion inhibitors, perfumes and colouring
agents may be added.
[0050] A principal advantage of the present invention is that an aqueous acid or acidic
salt solution may be readily and easily thickened. Generally the steps of obtaining
such thickened compositions will be - (a) add an appropriate amount of acid or acidic
salt to water and stir to dissolve, (b) add a thickening agent of the present invention
to the solution and stir until dissolved and (c) added other ingredients if required,
stirring to dissolve. It will be appreciated that since the thickening agent of the
present invention is defined to be soluble in the selected acidic salt or acid solution,
and as it will generally be easily wet, the step (b) above will be relatively rapid
unlike many of the prior art thickening agents, which whilst they may be soluble are
frequently difficult to wet.
[0051] Other advantages of the thickening agents of the present invention are that they
are relatively inexpensive and in use produce smooth, homogeneous immediate thickening.
Furthermore, thickened compositions are stable with respect to viscosity. For example,
the present inventor has found that a citric acid composition thickened with Farmin
O had no substantial change in viscosity when stored at room temperature for 12 months.
[0052] A still further advantage is that the present inventor has found that the compositions
of the invention have some surfactant and corrosion inhibition properties. The former
finding means that water immiscible substances such as fragrances may be directly
solubilized in a composition of the invention without requiring the addition of emulsifiers
or auxilliary solvents, and in compositions in which the surface active properties
are required, potentially less or no additional surfactant would be required.
[0053] The present inventor has also found that if only sufficient of an acid or an acidic
salt is present to just dissolve a thickening agent of the present invention, then
a composition of near neutral pH may be obtained. Thus, Farmin O may be used to thicken
lactic acid at a pH of 6.5. The advantage of this finding is that it may be used in
aqueous liquid cleaners in general.
[0054] The present inventor has further found that an acid or acidic salt which is usually
considered to be water insoluble at room temperature may be brought into solution
through the use of a thickening agent of the present invention, with thickening occurring.
The viscosity may be increased through the use of a strong ionic salt such as sodium
chloride. To prepare such compositions, the acid is dispersed in the water and the
thickening agent added with mixing. It is observed that as the acid and thickener
go into solution, the solution increases in viscosity.
[0055] Preferred compositions of this type include ethylenediaminetetraacetic acid with
Genamin S0302D as the thickening agent, potassium hydrogen tartrate with Genamin TA302D
as thickening agent and pentetic acid with Farmin O as thickening agent.
[0056] Hereinafter are a number of examples, 1 to 60, of the present invention, together
with comparative examples 1A and 1B, in which the viscosity, in centipoise, of each
was determined using a Brookfield RVT viscometer using a spindle and speed as appropriate
at 25°C. Note that the thickening agent is asterixed in each case. All of these examples
(except Nos. 27, 46 and 51) were produced by bringing the acid or acidic salt into
solution, adding the thickening agent and mixing until dissolved, and then adding
the other ingredients with mixing until dissolved.
[0057] Examples 27, 46 and 51 were prepared by dispersing the acid or acid salt in water,
adding the thickening agent and mixing until solution occurred, followed by sodium
chloride (if required) until a satisfactory viscosity was achieved.
[0058] Note that all examples were prepared under normal laboratory conditions.
Example 1
[0059]

Comparative
Example 1A
[0060]

Example 1B
[0061]

Example 2
[0062]

Example 3
[0063]

Example 4
[0064]

Example 5
[0065]

Example 6
[0066]

Example 7
[0067]

Example 8
[0068]

Example 9
[0069]

Example 10
[0070]

Example 11
[0071]

Example 12
[0072]

Example 13
[0073]

Example 14
[0074]

Example 15
[0075]

Example 16
[0076]

Example 17
[0077]

Example 18
[0078]

Example 19
[0079]

Example 20
[0080]

Example 21
[0081]

Example 22
[0082]

Example 23
[0083]

Example 24
[0084]

Example 25
[0085]

Example 26
[0086]

Example 27
[0087]

Example 28
[0088]

Example 29
[0089]

Example 30
[0090]

Example 31
[0091]

Example 32
[0092]

Example 33
[0093]

Example 34
[0094]

Example'35
[0095]

Example 36
[0096]

Example 37
[0097]

Example 38
[0098]

Example 39
[0099]

Example 40
[0100]

Example 41
[0101]

Example 42
[0102]

Example 43
[0103]

Example 44
[0104]

Example 45
[0105]

Example 46
[0106]

Example 47
[0107]

Example 48
[0108]

Example 49
[0109]

Example 50
[0110]

Example 51
[0111]

Example 52
[0112]

Example 53
[0113]

Example 54
[0114]

Example 55
[0115]

Example 56
[0116]

Example 57
[0117]

Example 58
[0118]

Example 59
[0119]

Example 60
[0120]

[0121] It is to be noted that the viscosity of Example 1, when compared with the viscosity
of water (1A) and 5% w/w citric acid (1 B), is substantially greater. A comparison
with an aqueous solution of the thickening agent in this case was not possible as
the thickening agent is water insoluble.
[0122] The examples 1 to 60 disclosed herein may be used for example as toilet bowl cleaners,
metal cleaners and brighteners and the like as well as applications such as gel batteries
1. A thickened aqueous composition comprising at least one acid of acidic salt, a
thickening agent which is a compound of the formula:

in which R, R
3 is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
Ri is hydrogen, a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl
group, R
2 is hydrogen, a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl
group, R
4 is a substituted or unsubstituted alkyl, aryl, or alkaryl, aralkyl or alkenyl group,
Rs is a substituted or unsubstituted alkyl, aryl, alkaryl, aralkyl or alkenyl group,
or R
1 and R
2 or R
4 and Rs when taken together comprise a substituted or unsubstituted heterocyclic ring,
provided that if either R, R
1 or R
2 is an alkyl or alkenyl group derived from a fatty acid obtained from a natural oil
or fat or an equivalent synthetic fatty acid, or is an alkaryl group containing from
8 to 12 carbon atoms in the alkyl moiety, then the other substituents are not respectively
of the formulae: [A]
x - H and [A]y - H where A is either ethoxy or propoxy and X, y are independently 1,
2 or 3, and optionally a strong ionic salt, the thickening agent and the acid or acidic
salt being together substantially water soluble, and
wherein the thickened aqueous composition has a viscosity of not less than 30 centipoise
at 25° C when mesured with a Brookfield RVT viscometer at 50 rpm using a No.1 spindle.
2. A composition as claimed in claim 1 wherein the thickening agent is water insoluble.
3. A composition as claimed in claim 1 or claim 2 wherein either of the groups R or
R3 contains at least six carbon atoms, preferably from eight to twenty four carbon atoms.
4. A composition as claimed in any one of claims 1 to 3, wherein the group R or R3 is an unsubstituted alkyl or alkenyl group.
5. A composition as claimed in claim 4 wherein R or R3 is derived from either a natural or synthetic source of tallow, soya bean oil, oleic
acid, palmitic or myristic acid.
6. A composition as in claim 4 or claim 5 wherein R or R3 is derived from either a natural or synthetic source of linolenic, ricinoleic, linoleic
or hexadecanoic acid.
7. A composition as claimed in any one of claims 1 to 6, wherein the groups R1 and R2 are independently a hydrogen atom, a lower unsubstituted alkyl group containing one
to four carbon atoms, preferably methyl, or a substituted alkyl group.
8. A composition as claimed in any one of claims 1 to 6 wherein the groups R4 and Rs are independently a lower unsubstituted alkyl group containing one to four
carbon atoms or a substituted alkyl group.
9. A composition as claimed in claim 8, wherein the groups R4 and Rs are independently a methyl, hydroxyethyl or hydroxypropyl group.
10. A composition as claimed in any one of claims 1 to 13 wherein the thickening agent
is a mixture of compounds of the formula I or a mixture of compounds of the formula
II.
11. A composition as claimed in any one of claims 1 to 10 wherein the acid is phosphoric,
sulphuric, boric, sulphamic, tartaric, citric, lactic, formic, acetic, glycollic,
pentetic, ethylenediaminetetraacetic, propionic, malic, adipic, maleic, malonic, succinic,
hydrofluoric, ascorbic or chloroacetic acid.
12. A composition as claimed in any one of claims 1 to 10, wherein the acidic salt
is monosodium citrate, sodium hydrogen sulphate, sodium dihydrogen orthophosphate,
disodium ethylenediaminetetraacetate, aluminium potassium sulphate, aluminium acetate,
potassium hydrogen tartrate or aluminium sulphate.
13. A composition as claimed in any one of claims 1 to 16 wherein the concentration
of thickening agent is in the range of from 0.1 to 10% w/w, preferably 0.4 to 5.0%
w/w.
14. A composition as claimed in any one of claims 1 to 18 wherein the concentration
of acid or acidic salt is not less than 0.01 % w/w preferably 0.1 to 300/0 w/w.
15. A composition claimed as in any one of claims 1 to 14 additionally including a
perfume, dye, sequestering agent, surfactant or bactericide.
16. A composition as claimed in any one of claims 1 to 15 wherein the strong ionic
salt is an alkali metal halide, an alkali metal sulphate, an ammonium halide ammonium
sulphate or a long chain quaternary ammonium compound.
17. A composition as claimed in any one of claims 1 to 16 further including a compound
effective in adjusting the upper and/or lower cloud point of the composition, preferably
a strong ionic salt anionic surfactant, cationic surfactant, nonionic surfactant,
amphoteric surfactant, a solvent miscible with the composition, or a mixture thereof.
18. A composition as claimed in claim 19 wherein the solvent is ethanol, isopropanol
butoxyethanol or dipropylene glycol methylether.
19. A method of forming a composition as claimed in any one of claims 1 to 18 comprising
dissolving in water (a) at least one acid or acidic salt, (b) a thickening agent which
is as defined in claim 1, and optionally (c) a strong ionic salt, the thickening agent
and the acid or acidic salts being together substantially water soluble, in amounts
sufficient to produce a viscosity of not less than 30 centipoise at 25° C when measured
with a Brookfield RVT viscometer at 50 rpm using a No. spindle.