Note: Descriptions are shown in the official language in which they were submitted.
t3323~8
SAFE ACIDIC HARD SURFACE CLEANER
This invention relates to a cleaner for hard
surfaces, such as bathtubs, sinks, tiles, porcelain an~ enamel-
ware, which xemoves soap scum, lime scale and grease from such
surfaoes without harming them. More particularly, the invention
relates to an acidic microemulsion that can be sprayed onto the
surface to be cleaned, and wiped off without usual rinsing, and
still leave the cleaned surface bright and shiny. The invention
also relates to a method for using such compositions.
Hard surface cleaners, such as bathroom cleaners and
scouring cleansers, have been known for many years. Scouring
cleansers normally include a soap or synthetic organic detergent
or surface active agent, and an abrasive. Such products can
scratch relatively soft surfaces and can eventually cause them to
15 ~ appear dull. Also, they are often ineffective to remove lime
~,
scale (usually encrusted calcium and magnesium carbonates) in
normal use. Because lime scale can be removed by chemical reac-
tions with acidic media various acidic cleaners have been
produced, and have met with various degrees of success. In some
instances such cleaners have been failures because the acid em~
ployed was too strong and damaged the surfaces bei~g cleaned. At
other times, the acidic component of the cleaner reacted objection-
ably with other components of the product, adversely affecting the
detergent or perfume, for example. Some cleaners required rinsing
afterward to avoid leaving objectionable deposits on the cleaned
`surfaces. As a result of research per~ormed in efforts to over-
come the mentioned disadvantages there has recently been made an
62301-1539
1332~
improved liquid cleaning composition in stable microemulsion
form which is an effective cleaner to remove soap scum, lime
scale and greasy soils from hard surfaces, such as bathroom
surfaces, and which does not require rinsing after use. Such a
product is described in Canadian patent application 582,71 for
STABLE MICROEMULSIO~ CLEANING COMPOSITIO~, filed November 10,
1988, by Loth, Blanvalet and Valange. In particular, Example 3
of that application discloses an acidic, clear, oil-in-water
microemulsion which is therein described as being successfully
employed to clean shower wall tiles of lime scale and soap
scum that had adhered to them. Such cleaning was effected by
applying the cleaner to the walls, followed by wiping or min-
imal rinsing, after which the walls were allowed to dry to a
good shine.
The described microemulsion cleaner of the patent
application is effective in removing lime scale and soap scum
~ form hard surfaces, and is easy to use, but it has been found
;~ that its mixture of acidic agents (succinic, glutaric and
adipic acids) could damage the surfaces of some hard fixtures,
such as those of materials which are not acid resistant. One
of such materials is an enamel that has been extensively em-
ployed in Europe as a coating for bathtubs, herein referred to
as European enamel. It has been described as zirconium white
:,
enamel or zirconium white powder enamel, and has the advantage
of being resistant to detergents, which makes it suitable for
-~ use on tubs, sinks, shower tiles and bathroom enamelware.
However, such enamel is sensitive to acids and is severely
damaged by use of the microemulsion acidic cleaner based on the
~30 three organic carboxylic acids previously mentioned. That
problem has been solved by the present invention, in which ad-
ditional acidic materials are incorporated in the cleaner with
'
A - 2 -
13~23~8
the organic acids, and rather than exacerbating the problem,
they prevent harm to such European enamel surfaces by such
organic acids. Also, a mixture of such additional acids, phos-
phonic and phosphoric acids, surprisingly further improves the
S safety of the aqueous cleaner for use on such European enamel
surfaces and decreases the cost of the cleaner. Thus, the present
invention allows the cleaning by the invented emulsion of European
enamel surfaces, as well as any other acid resistant surfaces of
bathtubs and other bathroom surfaces. However, the product should
not be used on various other materials that are especially
susceptible to attack by acidic media, such as marble.
In accordance with the present invention an acidic aqueous
cleaner ~or bathtubs and other hard surfaced items, which are acid
resistant or are of zirconium white enamel, which cleaner is of a
pH in the range of 1 to 4, and which removes lime scale, soap scum
and greasy soil from surfaces of such items without damaging such
surfaces, comprises: a detersive proportion of synthetic organic -~
detergent, which is capable of removing greasy soil from such sur-
faces; a lime scale and soap scum removing proportion of dicarboxylic
acid(s) having 2 to 10 carbon atoms therein; an aminoalkylene-
phosphonic acid in such proportion as to prevent damage to zirconium
white enamel surfaces of items to be cleaned by the dicarboxylic
acid(s) when the cleaner is employed to clean such surfaces; and an
aqueous medium for the detergent, dicarboxylic acid(s) and amino-
, .
alkylenephosphonic acid.
~`~ In the present compositions the synthetic organic detergent
~ . ~
may be any suitable anionic, nonionic, amphoteric, ampholytic, zwit-
terionic or cationic detergent or mixture thereof, but the anionic
and nonionic detergents are preferred, as are mixtures thereof. Of -
the anionics the more preferred are water soluble salts of lipophilicsulfonic and sulfuric acids, the lipophilic moieties of which include
; long chain aliphatic groups, preferably lomg chain alkyls, of 8 to 20
- 3 -
~3323~
carbon atoms, more preferably of 12 to 18 carbon atoms. Although
several different types of solubilizing cations may be present
in the detergents it will usually be preferred that they be
alkali metal, e.g., sodium or potassium or a mixture thereof,
ammonium, or lower alkanolamine, of 2 or 3 carbon atoms per
alkanol moiety. It is a desirable feature of the present invention
that sadium may be the alkali metal employed, and the emulsions
resulting will be stable and effective.
Much preferred salts o~ lipophilic sulfonic acids
are paraffin sulfonatefi, wherein the paraffin group i~ of 12 to
18 carbon atoms, preferably 14 to 17 carbon atoms. Otner useful
sulfonates are olefin sulfonates wherein the olefin starting
material is of 12 to 18 carbon atoms, e.g., 12 to 15, and
linear alkylbenzene sulfonates wherein the alkyl is of 12 to 18
carbon atoms, preferably of 12 to 16 carbon atoms, e.g., 12 or 13.
All such sulfonates will preferably be employed as their sodium
salts, but other salts are also operative.
Much preferred salts of lipophilic sulfuric acids are of
higher alkyl ethoxylate sulfuric acids, which may also be designat-
ed as higher alkyl ethyl ether sulfuric acids. The higher alkyls
of~such aompounds are of the chain lengths given above for this
class of anionlc detergents, 10 to 18 carbon atoms, and preferably
are of 10 to 14 carbon atoms, e.g., 12 or about 12 carbon atoms.
Such compounds should include from 1 to 10 ethylene oxide groups
per mole, preferably 3 to 7 ethylene oxide groups per mole, P.~.~$. A
,~ ~
~- preferred cation is sodium but the cations mentioned above for solu- -
bilizing functions may be emE)loyed in suitable circum~tances.
The nonionic detergents that are useful in this invention
may be any of the nonionic detergents known to the art (as may be
, ~
; ~ 30 the anionic detergents that satisfy the conditions set in this
specification~ Many ~uch detergents are described in the text
Surface Active Agents (Their Chemistry and Technology) by Schwartz
1-
~332~38
and Perry, and in the various annual editions of John W.
McCutcheon's Deter~ents an~ Emulslfiers. However, they will
u~ually be condensation pro~ucts of a lipophilic moiety, such as
a higher alcohol or phenol, or a propylene glycol or propylene
oxide polymer, with ethylene oxide or ethylene glycol. In some
of the condensation products~of ethylene oxide and higher fatty
alcohol or alkyl substituted l~henol (in which the alkyl on the
phenol nucleus is usually of 7 to 12 carbon atoms! preferably 9~,
some propylene oxide may be blen~ed with the ethylene oxide so that
the lower alkylene oxide moiety il~ the noniOniG detergent is mixed,
whereby the hydrophilic-lipophilic balance (HLB) may be controlled.
Much prefexred nonionic d~-tergents presen~ in the invented
emulsions will be condensation products of a fatty alcohol of
8 to 20 carbon atoms wlth from 3 to`l20 moles of ethylene oxide,
preferably of a linear alcohol of 9 '~to 15 carbon atoms, such as
9- 11 or 11- 13 carbon atoms or avera~ing about 10 or 12 car~ons~
with 3 to 15 moles of ethylene oxide,`such as 3-7 or S-9 moles of
ethylene oxide, e.g., about 5 or 7 moles tpereo~. In place of
the higher fatty alcohol one may use an`~lkylphenol, such as one of
8 to 10~carbon atoms in a linear alkyl, 0.g., nonylphenol, and the
phenol may be condensed with from 3 to 20 ethylene oxide groups,
preferably 8 to 15. Similarly functioning nonionic detergents that
are polymers o~ mixed ethylene oxide and propylene oxide may be
substituted, at least ~n part, for the other nonionics. Among sUch
~ are those sold ur.~ler the trademark Plurafac, such as PlurafacR
`~ Ra-~O and Piurafac ~F-400, available from BAS~. Preferred such
nonio~ics contain 3 tc 10 ethoxies, more preferably about 7, and
2 to 7 propoxy groups, more preferably about 4, and such are
- `condensed with a higher f~tty alcohol of 12-16, more preferably
13-15 carbon atoms to make a mole of nonionic d~tergent.
_
~ 3 ~ 2 ~ ~ ~ 62301-1539
The various nonionic detergents, and the anionic
detergents are often mixtures, which are within singular
designations herein.
The active acidic component of the emulsions is a
carboxylic acid which is strong enough to lower the pH of the
emulsion to one in the range of one to four. Various such
carboxylic acids can perform this function but those which have
been found effectively to remove soap scum and lime scale from
bathroom surfaces best, while still not destabilizing the
emulsion, are polycarboxylic acids, and of these the
dicarboxylic acids are preferred. of the dicarboxylic acids
group, which includes those of 2 to 10, preferably 3 to 8 --
carbon atoms, from oxalic acid through sebacic acid, suberic,
azelaic and sebacic acids are of lower solubilities and
therefore are not as useful in the present emulsions as the - ~i
other dibasic aliphatic fatty acids, all of which are
A . .
i~;preferably saturated and straight chained. Oxalic and malonic
acids, although useful as reducing agents too, may be too
strong for delicate hard surface cleanings. Preferred such
"::;~ 20 dibasic acids are those of the middle portion of the 2 to 10
carbon atom acid range, succinic, glutaric, adipic and pimelic
acids, especially the first three thereof, which fortunately
~,, are available commercially, in mixture. The diacids, after
being incorporated in the invented emulsion, may be partially
neutralized to produce the desired pH in the emulsion, for
;~ greatest functional effectiveness, with safety.
.,
~ Phosphoric acid is one of the additional acids that
~ .
helps to protect acid-sensitive surfaces being cleaned with the
present emulsion cleaner. Being a tribasic acid, it too may be
partially neutralized to obtain an emulsion pH in the desired
,~
range. For example, it may be partially neutralized to the
biphosphate, e.g. NaH2PO4, or NH4H2PO4.
: ::
-`` 1332338
62301-1539
Phosphonic acid, the other of the two additional
acids for protecting acid-sensitive surfaces from the
dissolving action of the dicarboxylic acids of the present
emulsions, apparently
: ..:: ~ . . .
. .:
~:
~:
~::
.'~ . , .
: r~ 6a
`
11 332338
exists only theoretically, but its derivatives are stable
and axe useful in the practice of the present invention. Such
are considered to be phosphonic acids, as that term is used in
this specification. The phosphonic acids are of the
structure OH
Y - P = O , wherein Y is any suitable
OH
substituent, but preferably Y is alkylamino or N-substituted
alkylamino. For example, a preferred phosphonic acid component
of the present emulsions is aminotris-)methylenephosphonic) acid,
which is o~ the formula N(cH2pH2o3)~ Among other useful phosphonic
acids are ethylenediamine tetra-(methylenephosphonic) acid,
hexamethylenediamine tetra-(methylenephosphonic) acid, and
diethylenetriamine penta-(methylenephosphonic) acid. Such class of
compounds may be described as aminoalkylenephosphonic acids con-
taining in the ranges of 1 to 3 amino nitrogens, 3 or 4 lower
alkylenephosphonic acid groups in which the lower alkylene is of
1 or 2 carbon atoms, and 0 to 2 alkylene groups of 2 to 6 carbon
atoms each, which alkylene(s) is/are present and join amino
nitrogens when a plurality of such amino nitrogens is present in
the aminoalkylenephosphonic acid. ~t has been found that such
aminoalkylenephosphonic acids, which also may be partially
neutralized at-the desired pH of the microemulsion cleaner, are
of desired stabilizing and protecting effect in the invented
cleaner, especially when present with phospho~ic~acid, preventing
harmful attacks on European enamel surfaces by the diacid(s) com-
ponents of the cleaner. Usually the phosphorus acid salts, if
present, will be mono-salts of each of the phosphoric and/or
phosphonic acid groups present.
- 7 -
` -
1332~
The water that is used in making the present micro-
emulsions may be tap water but is preferably of low hardness,
normally being less than 150 parts per million (p.p.m.) of -
hardness, as calcium carbonate. Still, useful cleaners can be made
from tap waters that are higher in hardness, up to 300 p.p.m.,
as CaC03. Most preferably the water employed will be distilled
or deionized water, in which the content of hardness ions is
less than 25 p.p.m., usually being nil. Employment of such de~
ionized water allows for the manufacture of a productof consistently
good qualities, independent of hardness variations in the aqueous
medium.
- Various other components may desirably be present in
the invented cleaners, including preservatives, antioxidants or
corrosion inhibitors, cosolvents, cosurfactants, multivalent ~-
metal ions, perfumes, colorants and terpenes (and terpineols),
but various other adjuvants conventionally employed in liquid
detergents and hard surface cleaners may also be present,provided
that they do not interfere with the cleaning and scum- and scale-
removal functions of the cleaner. Of the various adjuvants
(which are so identified because they are not necessary for the
productLon of an operative cleaner, although they may be very
de~irable components of the cleaner) the most important are con-
sidered to be the perfumes, which, with terpenes, terpineols and
~; hydrocarbons (which may be substituted for the perfumes or added
:~.".
~ to them) function as especially effective solvents for greasy soils
on hard surfaces being cleaned, andform the dispersed phases of
oil-in-water (o/w~ microemulsions. Also of functional importance
are the co-surfactant and polyvalent metal ions, with the former
helping to stabilize the microemulsion and the latter aiding in im-
~, ~
proving detergency,;especially for more dilute cl~eaners,and when
- 8 -
~ 3~233~
the polyvalent salts of the anionic detergent employed are more
effective detergents against the greasy soil encountered in use.
The various perfumes that have been found to be useful
in forming the dispersed phase of the o/w microemulsion cleaners
may be those normally employed in cleaning products, and preferably
are normally in liquid state. They include esters, ethers, alde-
hydes, alcohols and alkanes employed in perfumery but of most
importance are the essential oils that are high in terpene content.
It appears that the terpenes (and terpineols) coact with the
detersive components of microemulsions to improve detergency of
the invented compositions, in addition to forming the stable dis-
persed phase of the microemulsions. In the present invention it
has been found that especially when a piney perfume is being em-
ployed, one can decrease the proportion of comparatively expensive
such perfume and can compensate for it with alpha-terpineol, and
in some instances with other terpenes. For example, for every 1%
of perfume one can substitute from 60 to 90% of it, e.g., about 80%,
with alpha-terpineol, and obtain essentially the same piney scent,
wi~h good cleaning and microemulsion stability. Similarly, terpenes
and other terpene-like compounds and derivatives may be employed,
but alpha-terpineol is considered to be the best.
The polyvalent metal ion present in the invented cleaners
may be any suitable such ion, including magnesium (usually pre-
ferred), aluminum, copper, nickel, iron or calcium, and the ion
or mixture thereof may be added in any suitable form, sometimes as
an oxide or hydroxide, but usually as a water soluble salt. It
appears that the polyvalent metal ion reacts with the anion
of the anionic detergent (or replaces the detergent ca~ion~ or makes
~ ~ -
an equivalent solution in the emulsion), which improves detergency
and generally improves other properties of the product, too. If
the EJolyvalent metal ion reacts with the detergent anion to form
an insoluble product such polyvalent ion should be avoided. For
_ g _
~332~g
example, calcium reacts with paraffin sulfonate anion to form
an insoluble salt, so calcium ions, such as might be obtained from
calcium chloride, will be omitted from any emulsion cleaners of this
invention that contain paraffin sulfonate detergent. Similarly,
those polyvalent ions or other components of the invented compo~
sitions that will react adversely with other components will also
be omitted. As was mentioned previously, the polyvalent metal ion
will preferably be magnesium, and such will be added to the other
emulsion components as a water soluble salt. A preferred such salt
is magnesium sulfate, usually employed as its heptahydrate
(Epsom salts), but other hydrates thereofor the anhydride may be
used too. Generally, the sulfates of the polyvalent metals will be
used because the sulfate anion thereof is also the anion of some
of the anionic detergents and is found in some such detergents as
a byproduct of neutralization.
The cosurfactant component(s) of the microemulsion
cleaners reduce the interfacial tension or surface tension between
the lipophilic droplets and the continuous aqueous medium to a
value that is often close to 10-3 dynes/cm., which results in
spontaneous disintegrations of the dispersed phase globules until
they become so small as to be invisible to the human eye, forming
' a clear microemulsion. In such a micxoemulsion the surface area of
the dispersed phase increases greatly and its solvent power and
grease removing capability are also increased, so that the micro-
emu}sion is significantly more effective as a cleaner for removing
greasy soils than when the dispersed phase globules are of ordinary
emulsion size. Among the cosurfactants that are useful in the
~ ~
invented cleanexs are: water soluble lower alkanols of 2 to 4 carbon
atoms per molecule (sometimes preferably 3 or 4); polypropylene
glycols of 2 to 18 propoxy units; monoalkyl lower glycol ethers of
the formula RO(X)nH , wherein R is Cl_4 alkyl, X is C~2CH20,
CH2CH2CH20 or C~(CH3)CH20, and n is from 1 to 4; monoalkyl esters
- 1 0 - , ~ :
, .
~ 33233~
'A
of the formula RlO(X)nH wherein R1 is C2_4 acyl and X and n are
as immediately previously described; aryl substituted alkanols of
1 to 4 carbon atoms; propylene carbonate; aliphatic mono-, di- and
tricarboxylic acids of 3 to 6 carbon atoms; mono-, di- and tri
hydroxy substituted aliphatic mono-, di- and tricarboxylic acids of
3 to 6 carbon atoms; higher alkyl ether poly-lower alkoxy carboxylic
acids, lower alkyl mono-, di- and triesters of phosphoric acid
wherein the lower al~yl is of 1 to 4 carbon atoms; and mixtures
thereof.
Representative of such cosurfactants are succinic, glu-
taric and adipic acids, diethylene glycol monobutyl ether,
dipropylene glycol monobutyl ether and diethylene glycol mono-
isobutyl etherr which are considered to be the most effective.
From the foregoing discussion of useful cosurfactants in
the present cleaners it is apparent that succinic, glutaric and
adipic acids, and a mixture of such componen*s,are useful for
lowering the pH of the product so that it removes soap scum and
lime scale easily from surfaces to be cleaned, and at the same
time they function as cosurfactants, improving the appearance of
the product and making it more effective for removing grease from
such surfaces. Similar dual effects may be obtained by use of
others of the named acidic materials that have cosurfactant
activities in the described cleaners.
Although it is highly preferred that the present
~ .
cleaning compositions be in the form of aqueous microemulsions
it is within the invention to utilize less preferred emulsions
(wherein the dispersed phase globules are larger in sizes), but
in such cases the cleaning power of the product will be less be-
cause there will not be as good contact of the cleaner with the
surface being tr~ated. Also, although mocroemulsio~s are highly
- 11 -
~ 3 3 2 3 ~ ~ 62301-1539
preferred embodiments of the invention, other emulsions and
other forms of the composition may be used, such as gels,
pastes, solutions, foams, and "aerosols", which include aqueous
media.
In the invented cleaners it is important that the
proportions of the components are in certain ranges so that the
product may be most effective in removing greasy soils, lime
scale and soap scum, and other deposits from the hard surfaces
subjected to treatment, and so as to protect such surfaces
during such treatment. As was previously referred to, the
detergent should be present in detersive proportion, sufficient
to remove greasy and oily soils; the proportion(s) of car-
, . . .
boxylic acid(s) should be sufficient to remove soap scum and
lime scale; the phosphonic acid or phosphoric and phosphonic
acids mixture should be enough to prevent damage of acid sen-
sitive surfaces by the carboxylic acid(s), and the a~ueous
medium should be a solvent and suspending medium for the re-
~; quired components and for any adjuvants that may be present,
too~ Normally, such percentages of components will be 2 to 8%
of synthetic anionic organic detergent(s), 1 to 6% of synthetic
organic nonionic detergent(s), 2 to 6 or 10~ of aliphatic car-
:~ ,
boxylic acids (preferably diacids), 0.05 to 1 or 5% of phos-
i phoric acid or monosalt thereof, and 0.005 to 2%, preferably
0.01 to 0.2% of phosphonic acid(s), aminoalkylenephosphonic
acid(s), or mono-phosphonic salt(s) thereof; and the balance
water and adjuvant(s), if any are present. Of the carboxylic
acids it is preferred that a mixture of succinic, glutaric and
adipic acids be employed, and the ratio thereof will most pre-
30 ferably be in ~he range of 1-3:1-6:1-2, with 1:1:1 and about
2:5:1 ratios being most preferred. The ratios of phosphonic
,
A 12 -
`` ~3~2~3~
62301-1539
acid (preferably aminoalkylenephosphonic acid) to phosphoric
acid to aliphatic carboxylic diacids (or carboxylic acids) are
usually about 1 : 1-20 : 20-500, preferably being 1 : 2-10 :
10-200, and more preferably being about 1 : 4 : 25, 1 : 7 : 170
and 1 : 3 : 2S, in three representative formulas. However,
one may have ranges as wide as 1: 1-2,000 : 10-4,000 and some-
times the preferred range of dicarboxylic acid to phosphonic
acid is 5:1 to 250:1. Similarly, a mixture of succinic,
glutaric and adipic acids may be of ratio of 0.8 -4 : 0.8 - 10
:1 and the ratio of dicarboxylic acid to phosphonic acid may be
5:2 to 25:1.
Usually there will be present in the cleaner, especi-
ally when paraffin sulfonate is the detergent, 0.05 to 0.5 or
5%, and preferably 0.1 to 0.3~ of polyvalent ion, preferably
magnesium or aluminum, and more preferably magnesium. Also,
the percentage of perfume will normally be in the 0.2 to 2%
range, preferably being in the 0.5 to 1.5% range, of which
perfume at least 0.1% is terpene or terpineol. The terpineol
is alpha-terpineol and is preferably added to allow a reduction
in the amount of perfume, with the total perfume (including the
alpha-terpineol) being 50 to 90% of terpineol, preferably about -
80% thereof.
For preferred formulas of the present cleaners, which
are different in that one contains two anionic detergents and
the other only one, the latter will contain 3 to 5% of sodium
` paraffin sulfonate wherein the paraffin is C14 17, 2 to 4% of
~` nonionic detergent which is a condensation product of a fatty
alcohol of 9 to 15 carbon atoms with 3 to 15 moles of ethylene
,:~
~- 30 oxide per mole of higher fatty alcohol, 3 to 7% of a 1:1:1 or
2:5:1 mixture of succinic, glutaric and adipic acids, 0.1 to
~A 13 -
~ 3 3 2 3 ~ g 62301-1539 ~
0.3% of phosphoric acid, 0.03 to 0.1% of aminotris-(methylene- :
phosphonic acid), 0.1 to 0.2% of magnesium ion, 0.5 to 2~i of ~:
perfume, of which 50 to 90~ thereof is alpha-terpineol, 0 to 5
of adjuvants and 75 to 90~ of water. More preferably, such
cleaner will comprise or consist essentially of about 4% of
sodium paraffin (C14_17) sulfonate, about 3~i of the nonionic
detergent, about 5% of 2:5:1 mix of the dicarboxylic acids,
about 0.2~i of phosphoric acid, about 0.05% of aminotris-
(methylenephosphonic acid), about 1% of perfume, which includes
about 0.8% of alpha-terpineol, about 0.7% of magnesium sulfate
(anhydrous), about 1-3% of adjuvants and about 81-83~ of water.
The other preferred formula comprises 0.5 to 2% of
sodium paraffin sulfonate wherein the paraffin is C14_17, 2 to
4% of sodium ethoxylated higher fatty alcohol sulfate wherein
the higher fatty alcohol is of 10 to 14 carbon atoms and which -
contains 1 to 3 ethylene oxide groups per mole, 2 to 4% of
nonionic detergent which is a condensation product of fatty
alcohol of 9 to 15 carbon atoms with 3 to 15 moles of ethylene
oxide per mole of fatty alcohol, 3 to 7% of a 1:1:1 mixture of
~: succinic, glutaric and adipic acids 0.1 to 0.3% of phosphoric
~: acid, 0.01 to 0.05% of aminotrls-(methylenephosphonic acid),
0.09 to 0.17% of magnesium ion, 0.5 to 2% of perfume, of which
at least 10% is terpene(s) and/or terpineol, 0 to 5~ of ad- ;~
juvant(s) and 75 to 90% of water. More preferably, such
cleaner, with two anionic detergents, will comprise or consist
essentially of about 1% of sodium paraffin (C14-17) sulfonate,
about 3% of sodium ethoxylated higher fatty alcohol sulfate
wherein the higher fatty alcohol is lauryl alcohol and the
degree of ethoxylation is 2 moles of ethylene oxide per mole,
about 3% of nonionic detergent which is a condensation product
of a Cg_ll linear alcohol and 5 moles of ethylene oxide, about
~: 5% of
- 14 -
~ 3 3 2 3 3 8 62301 153g
a 1:1:1 mixture of succinic, glutaric and adipic acids, about
0.2% of phosphoric acid, about 0.03~ of aminotris-(methylene-
phosphonic acid), about 0.7% of magnesium sulfate (anhydrous),
about 1-2% of adjuvant and about 84-85% of water.
The pH of the various preferred microemulsion
cleaners is usually 1-4, preferably 1.5-3.5, e.g. 3. The water
content of the microemulsions will usually be in the range of
75 to 90%, preferably 80 to 85%, and the adjuvant content will
be from 0 to 5~, usually 1 to 3%. If the pH is not in the
desired range it will usually be adjusted with either sodium
hydroxide or suitable acid, e.g., sulfuric acid, solutions, but
normally the pH will be raised, not lowered, and if it is to be
lowered more of the dicarboxylic acid mixture can be used,
instead.
~,
''
~''
::
- 14a -
~ r~^
A
~332338
The cleaners of the invention, in micxoemulsion form,
are clear o/w emulsions and exhibit stability at room temperature
and at elevated and reduced temperatures, from 10 to 50C.
They are readily pourable and exhibit a viscosity in the range of
2 to 150 or 200 centipoises, e.g., 5 to 40 cp., as may be desired,
with the viscosity being controllable, in part, by addition to the
formula of a thickener, such as lower alkyl celluloses, e.g., methyl
cellulose, hydroxypropyl methyl cellulose, or water soluble resin,
e.g., polyacrylamide, polyvinyl alcohol. Any tendency of the
product to foam objectionably can be counteracted by incorporating
in theformula free fatty acid or soap, in minor proportion, as is
known in the detergent art (at low pH the soap turns to acid).
The liquid cleaners can be manufactured by mere mixing of
the various components thereof, with orders of additions not being
critical. However, it is desirable for the various water soluble
components to be mixed together, the oil soIuble components to be ~ -
~; mixed together in a separate operation, and the two mixes to be
admixed, with the oil soluble portion being added to the water
soluble portion (in the waterj with stirring or other agitation.
~ i ,
In some instances such procedure may be varied to prevent any un-
desirable reactions between components. For example, one would not
add concentrated phosphoric acid directly to magnesium sulfate or to
; a dye, but such additions would be of aqueous solutions, preferably
dilute, of the components.
The cleaner may desirably be packed in manually operated
spray dispensing containers, which are usually and preferably made
of synthetic organic polymeric plastic material, such as poly-
` ~ethylene, polypropylene or polyvinyl c~loride (PVC). Such containers
- also preferably include nylon or other non-reactive plastic closure,
- 15 -
~3~233~
spray nozzle, djip tube and associated dispenser paxts, and the
resulting packaged cleaner is ideally suited for use in "spray and
wipe"applications. However, in some instances, as when lime scale
and soap scum deposits are heavy, the cleaner may be left on until
it has dissolved or loosened the deposits, and may then be wiped
off, or may be rinsed off, or multiple applications may be made,
followed by multiple removals, until the deposits are gone. For
spray applications the viscosity of the microemulsion (or ordinary
emulsion, if that is used instead) will desirably be increased so
that the liquid adheres to the surface to be cleaned, which is es-
pecially important when such surface is vertical, to prevent
immediate run-off of the cleaner and consequent lcss of effective-
ness. Sometimes, the product may be formulated as an "aerosol
spray type", so that its foam discharged from the aerosol container
will adhere to the surface to be cleaned. At other times the
aqueous medium may be such as to result in a gel or paste, which
is deposited on the surface by hand application, preferably with
a sponge or cloth, and is removed by a combination of rinsing and
wiping, preferably with a sponge, after which it may be left to
dry to a shine, or may be dried with a cloth. Of course, when
feasible, the cleaned surface may be rinsed to remove all traces of
acid from it.
The following examples illustrate but do not limit the
`~ invention. All parts, proportions and percentages in the examples,
the specification and claims are by weight and all temperatures are
in C. unless otherwise indicated.
:
~ .
- 16 -
; -
~2~
XAMPLE 1
Component % (by weight~
Sodium paraffin sulfonate (paraffin of .1.00
C14-17 )
Sodium lauryl ether sulfate (2 moles of 3.00
ethylene oxide [EtO] per mole)
Cg_l linear alcohol ethoxylate nonionic 3.00
de~ergent (5 moles of EtO per mole)
Magnesium sulfate heptahydrate (Epsom salts) 1.35
Succinic Acid 1.67
Glutaric Acid 1.67
Adipic Acid 1.67
Aminotris (methylenephosphonic acid) 0.03
Phosphoric Acid 0.20
Perfume (contains about 40% terpenes) 1.00
Dye (1% aqueous solution of blue dye) 0.10
Sodium hydroxide (50% aqueous solution; decrease q.s.
~: water amount by amount of NaOH solution used)
: Water (deionized) 85.31
: 20 100.00
The microemulsion cleaner is made by dissolving the
detergents in the water, after which the rest of the water soluble
materials are added to the detergent solution, with stirring, except
: for the perfume and the pH adjusting agent (sodium h~droxide
25 : solution). The pH i6 adjusted to 3.0 and then the perfume is
stirred into the aqueous solution, instantaneously generating the
desired microemulsion, which is clear blue, and of a viscosity in
the.range of.2-20-cp, If the viscosity is lower or if it is con-
sidered desirable for it to be increased there may be incorporated
in the formula about 0.1 to 1% of a suitable gum or resin, such
as~sodium carboxymethyl cellulose or hydroxypropylmethyl cellulose,
~:: or polyacryIamide or polyvinyl aclohol, or a suitable mixture
, ~ .
thereof.
17 -
~1 3~2~38
The acid cleaner is packed in polyethylene squeeze
bottles equipped with polypropylene spray nozzles, which are
adjustable to closed, spray and stream positions. In use, the
microemulsion is sprayed onto "bathtub ring" on a bathtub, which
also includes lime scale, in addition to soap scum and greasy soilO
The rate of application is about 5 ml. per 5 meters of ring (which
is about 3 cm. wide). After application and a wait of about two
minutes the ring is wiped off with a sponge ~nd is sponged of~ with
water. It is found that the greasy soil, soap scum, and even the
lime scale, have been removed effectively. In those cases where the
llme scale is particularly thick or adherent a second application may
be desirable, but that is not considered to be the norm.
The tub surface ma~ be rinsed because it is so easy to
rinse a bathtub (or a shower) but such rinsing is not necessary.
lS Sometimes dry wiping will be sufficient but if it is desired to
remove any acidic residue the surface may be sponged with water
or wiped with a wet cloth but in such case it is not necessary to
use more than ten times th~ weight of cleaner applied. In other
words, the surface does not need to be thoroughly doused or rinsed
with water, and it still will be clean and shiny (providing that
it was originally shiny). In other uses of the cleanerj it may be
employed to clean shower tiles, bathroom floor tiles, kitchen tiles,
,:~
~ sinks and enamelware, generally, without harming the surfaces
~.
thereof. It is recognized that many of such surfaces are acid-
resistant but a commercial product must be capable of being used
:
without harm on even less resistant surfaces, such as European
white enamel (often on a cast iron or sheet steel base), which
is sometimes referred to as zirconium white powder enamel. It is
a feature of the cleaner described above (and other cleaners of
this invention) that they cleanhard surfaces effectively, ~ut they
- 18 -
:
~3~23~
do contain ionizable acids and therefore should not be applied to
acid-sensitive surfaces. Nevertheless, it has been found that they
do not harm European white enamel bathtubs, in this.example, which are
seriously affected by cleaning with preparations exactly like
that of this example except for the omission from.them of .~
the phosphonic acid or.the phosphonic-phosphoric acid mixture.
The major component of the formulation that protects the
Europea~ enamels is the phosphonic acid, and in the formula the
amount of such acid has been reduced below the minimum normally re-
quired at a pH of 3. Yet, although 0.5% is the minimum normally,when the phosphoric acid is present, which is ineffective in itself
at such pH, it increases the effect of the phosphonic acid, allow-
ing a reduction in the proportion of.the more expensive phosphonic
acid
In variations of the described formula, all components
are kept the same and in the same proportions except for water, and
phosphonic and phosphoric acids. In Experiment la, 0.05% of
aminotris-(methylenephosphonic acid) is employed and the phosphoric
acid is omitted; in Experiment lb, 0.5% of ethylene diamine tetra-
(methylenephosphonic.acid) is employed, with no phosphoric acid;
in Experiment lc,;0.5% of hexamethylene diamine tetra-(methylene~
phosphonic acid) is used, with no phosphoric acid; in Experiment ld, ~:~
0.4~ of;diethylene triamine penta-(methylenephosphonic acid) is
present, without phosphoric acid; and in Experiment le, 0~10% of
diethylene triamine penta-(methylenephosphonic acid) is employed,
~; with 0.60% of phosphoric acid. The cleaning powers of formulas ld
.~ and le are about equivalent, showing that the presence of the
phosphoric acid, essentially inactive as a protector of surfaces
against the effects of the carboxylic acids present in the formula,
decreases the proportion of phosphonic acid to protect the surfaces
;~ to 1/4 of that previously necessary. Similar effects are obtainable
when phosphoric acid is used in the lb and lc formulas in about
the same proportions as in Example 1 and Example le.
-- 19 --
13~2~3~
If excessive foaming is encountered in use of the cleaner one may
add an anti-foaming agent such as a silicone or a ¢oco fatty acid.
Al~ernatively, coco-diethanolamide may be added to increase foaming.
EXAMPLE 2
Component ~ (by weight)
Sodium paraffin sulfonate (Cl4_l7 paraffin)
Nonionic detergent (condensation product of one 3.00
mole of fatty Cg_ll alcohol and 5 moles EtO)
Magnesium sulfate heptahydrate l.50
Mixed succinic, glutaric and adipic acids (l:l:l) 5.00
Aminotris-(methylenephosphonic acid) 0.03
Phosphoric acid 0.20
Perfume l.00
Dye 11% a~ueous solution of blue dye) 0.05
Sodium hydroxide (50% aqueous solution; decrease water ~.s
amount by amount of NaOH solution used)
Water, deionized 85.22
00.00
The compositions of this example are made in the same
manner as those of Example l and are tested in the same way, too,
with similar good results. The microemulsions are a clear lighter
blue and the pH thereof is adjusted to 3Ø The cleaners easily
remove soap scum and greasy soils from hard surfaces a~d loosen and
facilitate removal of lime scale, too, with minimal rinsing or
spongeing, as reported in Example l. The presence of the aminotris-
;~ ~methylenephosphonic acid) prevents harm to the acid sensitive
surfaaes by the carboxylic acids, and the presence of the phosphoric
acid allows reduction in the proportion of aminotris-(methylene-
phosphonic acid ) used. For example, in Example 2a, without any
phosphoric acid present,it takes 0.10% of the aminotris-(methylene-
phosphonic acid) to prevent harm to European enamel by the cleaning
composition. Similarly, in Example lb, wherein the formula is the
same except that the phosphonic and phosphoric acids are replaced
by 0.20% of phosphonic acid (diethylene triamine penta-(methylene-
phosphonic acid) and 0.6% o~ phosphoric acid, European enamel is
- 20 -
13~23~
unharmed, whereas to obtain the same desirable effect without the
phosphoric acid present requires 0.50% of the phosphonic acid.
Similar results are obtained when the 0.5% of the phosphonic
acid is replaced by the same proportion of ethylene diamine tetra-
(methylenephosphonic acid) or hexamethylene dlamine tetra-(methylene- ;
phosphonic acid), with and without supplemental phosphoric-acid.
Thus, from this example (and Example 1~ it is seen that
phosphoric acid, which is essentially ineffective to protect
acid-sensitivé surfaces against actions of~carboxylic acids in the
present cleaners, improves the protective effects of phosphonic
acids, and does so significantly~for European bathtub enamel.
--
EXAMPLE 3
Component % (by weight)
Deionized water 82.339
lS C14_17 paraffin sodium sulfonate (60% active, 6.670
~ostapur SAS)
* Mixture of G utaric, succinic and adipic acids 5.000
B (mf'd~ by GAF Corp.)
Nonionic detergent (Plurafac RA-30, ethoxypropoxy 3.000
higher fatty alcohol, mf'd. by BASF-Wyandotte)
Epsom salts 1.500
Aminotris-(methylenephosphonic acid) 0.050
, . i
Phosphoric acid (85%~ 0.230
`~ ; Perfume (pine scent type, containing terpenes) 0.200
Alpha-terpineol (perfume substitute) 0.800
Formalin (preservative) 0.200
2,6-Di-tert-butyl-para-cresol (antioxidant)0.010
CI Acid Blue 104 dye -0.001
100.000
* 57.5% glutaric acid, 27% succinic acid and 12% of adipic acid
The above formula is made in the manner previously
described and is similarly tested and found satisfactorily to
- 21 -
*~T~ f~
'~,.' .
~l332338
clean acid sensitive hard surfaced items, such as tubs and sinks -
of cast iron or sheet steel coated with European enamel, of greasy
soils on them, and to facilitate removals of soap scums and lime
scales from such surfaces. When the phosphonic and phosphoric acids ~;~
are omitted from the formula, or when only the phosphonic acid is
omitted, the cleaner attacks such surfaces and dissolvés them. The
presence of the phosphoric acid allows a reduction in the propo~tion
of the phosphonic acid that is required to inhibit the cleaner
so that it will not attack the European enamels, and that reduction
is significant, especially for economic reasons, but also function-
ally. The alpha-terpineol replaces some of the perfume and helps
in the formation of the microemulsion, while not destroying the
pleasant cent that the perfume imparts to the product, and such
results are obtainable with other pine-type perfumes. The
alpha-terpineol, like the terpene components of a pine-type perfume,
facilitates microemulsion formation, but the terpineol is even
more active because it is essentially 100% of terpene type compound,
whereas the perfumes are usually less than 50~ of terpenes.
EXAMPLE 4
! ~ 20 When varlations are made in the formulas given above,
- by substituting different anionic and nonionic detergents, of
typeæ desaribed herein, by utilizing other polyvalent salts
(or omitting them), by employing other phosphonic acids, with or
without phosphoric acid, and by varying the proportions of com-
25 ponents + 10%, 20% and 30%, within the ranges given in the
specification, useful microemulsion cleaners are obtainable that
will satisfactorily clean hard surfaces and remove soap scum and
lime scale from them, without damaging them, even when they are of
Europ~an enamel. The products preferabiy contain phosphoric acid,
- 22 -
~33233~
which improves the protective action of the phosphonic acid
component, but it is within the invention to omit the phosphoric
acid, if that is considered to be desirable and feasible. The
cleaners are preferably in microemulsion form but even if the
microemulsion should "break" to an ordinary emulsion the product
will be useful as an effective cleaner, so such emulsions are also
within the invention. It may be preferred to dispense the cleaner
from a spray bottle but it can be packaged in conventional bottles,
also. It may be made in paste or gel form so as to make it more
adherent to surfaces to which it is applied, so that it will remain
on them, working to attack the lime scale, rather than running down
off the surface. Furthermore, while mixtures have been mentioned in
this specification, even where they were not specifically referred
to; it should be considered that mention of a single component in-
;~ 15 cludes reference to mixtures of such components in the invented
cleaners.
This invention has been described with respect to
illustrations and embodiments thereof but it is not to be limited
to them because one of ordinary skill in the art will be able,
with the benefit of applicants' teaching before him/her, to utilize
, substitutes and equivalents without departing from the invention.
,. ~
, ~
,, ~
, ~:
- 23 -
~ "
