Oven cleaning composition

A shear thickening oven cleaning composition having a viscosity at room temperature at a shear rate of 2 radians/second for 30 seconds of about 1 to about 110 Pa.s and a viscosity at room temperature at a shear rate of 10 radians/second for 30 seconds of about 2 to about 190 Pa.s which comprises by weight percent of about 5 to about 50 of an alkali metal silicate; about 0.1 to about 25 of a cyclic nitrogen containing compound; about 0.01 to about 4.0 of an alkanolamine; about 0 to 15 of at least one surfactant and the balance being water.

FIELD OF THE INVENTION 
This invention relates to shear thickening compositions in the form of 
liquids, sprays, gels and pastes, which remove dried-on and cooked-on food 
and other difficult-to-remove soils from kitchen utensils, flatware, 
dishes, glassware, cookware, bakeware, cooking surfaces, and surrounding 
areas in a convenient, easy, timely and mild manner. 
Of the difficult-to-remove soils, the most severe is the baked and/or 
burned-on (especially when reheated and/or allowed to build up over time). 
Soil categories include grease, meat (including skin), dairy, fruit pie 
filling, carbohydrate and starch. Soiled substrate categories include 
aluminum, iron, stainless steel, enamel, Corningware, Pyrex and other 
glass cookware. 
BACKGROUND OF THE INVENTION 
Current light duty liquid detergents are dramatically deficient in these 
areas. The consumer has to soak soiled items for long periods of time in 
these solutions, and then use harsh cleaning methods (scouring with steel 
wool or scouring cleanser) to remove the remaining soil. 
To speed up the process and increase efficacy of cleaning these soils, the 
consumer will resort to heat, scraping and harsh chemicals (e.g. caustic 
oven cleaners). 
Deficiencies in these cleaning methods include time consumption for soaking 
and scouring, physical effort required for scouring and scraping, 
irritation to hands from harsh cleaning chemicals and methods, damage to 
objects from harsh chemicals and methods, unpleasant fumes and odors and 
danger from heated solutions. Though non-caustic cleaners are listed in 
the literature, none are directed to the cleaning compositions of the 
present invention. 
U.S. Pat. No. 4,575,530 (Mar. 11, 1986) describes hydrocarbon solution 
additives which are polyampholytes which incorporates cationic and anionic 
moieties on the same polymeric backbone. These hydrocarbon solutions have 
shear thickening properties. 
U.S. Pat. No. 4,536,539 (Aug. 20, 1985) claims include increasing the 
viscosity of water under increasing shear rates (22.0--approaching 100 
sec.sup.-1). This shear thickening behavior is primarily attributed to the 
increase in apparent molecular weight of the interpolymer complex through 
formation of intermolecular ionic linkages. 
The instant patent teaches that these thickened silicates show shear 
thickening (dilatency), which is an increase in viscosity as shear rate is 
increased. Furthermore, the viscosity values at each shear rate are 
independent of the timescale of the experiment. Once the shear rate is 
applied, the viscosity reaches a steady value after a few seconds up to 
several minutes. Shear thickening occurs when the applied shear forces 
predominate the interparticle forces. The shear forces change the 
dispersion from a certain degree of order to clusters of particles. Shear 
thickening behavior is dependent on particle shape, size and size 
distribution; particle volume fraction; type and strength of 
inter-particle interaction; continuous phase viscosity and the 
experimental parameters characterizing the shear thickening. These 
parameters include the type, rate and duration of the applied shear 
deformation. 
SUMMARY OF THE INVENTION 
The shear thickening pre-spotting compositions of the present invention 
comprises a surfactant, water, an alkali metal silicate and imidazole. 
These shear thickening compositions may be formulated as clear, 
single-phase liquids, gels, or pastes and dispensed from bottles, squeeze 
bottles or paste dispensers. It has been found that applying the 
caustic-free compositions of the present invention to soiled surfaces 
removes the above mentioned soils at ambient temperature in a relatively 
short period of time (from 10 to 60 minutes) without need for heat, long 
soaking times, scouring or harsh chemicals. 
All of the oven cleaning compositions disclosed in the prior art do not 
possess shear thickening properties. These compositions of the prior art 
are shear thinning as the rate of shear is increased. In other words, as 
the shear rate is increased as in the process of scrubbing, the viscosity 
of the composition will decrease. The compositions of the instant 
invention exhibit shear thickening properties at about 25.degree. C. (room 
temperature) which means that as the shear rate is increased the 
compositions will shear thicken. The viscosity value at a given shear rate 
is independent of the time scale of the experiment. In a scrubbing process 
which causes an increase in the shear rate, the viscosity of the 
composition will increase and the composition will exhibit gel-like 
properties. This shear thickening property of the compositions of the 
instant invention make them especially useful on vertical surfaces because 
of their tendency not to run off of the vertical surface which is being 
cleaned as compared to the prior art compositions. 
The viscosity measurements made on the instant composition are made on 
compositions that have not been subject to a prior stress as for example 
the viscosity measurements made in U.S. Pat. No. 4,871,467, wherein the 
composition is subjected to a stress which causes a decrease in viscosity 
and then the stress is removed from the composition and a recovery in 
viscosity occurs in that the viscosity increases to the original viscosity 
of the composition that it exhibited prior to the composition having been 
subjected to stress. The compositions of U.S. Pat. No. 4,871,467 are shear 
thinning and are not shear thickening. The viscosity of the compositions 
of U.S. Pat. No. 4,871,467 as shear is applied never increases above the 
initial viscosity of the composition at rest (no shear applied). 
Accordingly, it is an object of the present invention to provide oven 
cleaning composition which is shear thickening at about 25.degree. C. upon 
increasing shear rate. 
The oven cleaning compositions according to the present invention comprise 
approximately by weight: 
(a) from 5% to 50%, preferably 10% to 40%, of an alkali metal silicate; 
(b) 0 to 5% of a surfactant selected from the group consisting of anionic 
surfactants and nonionic surfactants and mixtures thereof; 
(c) 0 to 10% of a builder selected from the group consisting of alkali 
metal salts of polyphosphates, pyrophosphates, citrates and carbonates and 
mixtures thereof; 
(d) 0.05% to 4% of an amine selected from the group consisting of 
monoethanolamine, diethanolamine and triethanolamine and mixtures thereof; 
(e) 0.1% to 25% of a cyclic nitrogen containing compound such as an 
imidazole; 
(f) 0 to 30%, preferably 0.1% to 15% of an organic compound having the 
formula 
EQU C.sub.n H.sub.2n+2-x (OH).sub.x 
wherein x is 1,2 or 3 and n is about 1 to about 20, more preferably about 1 
to about 8; 
and 
(g) the balance being water, wherein the composition does not contain any 
polymeric thickeners such as crosslinked polyacrylic acid polymers such as 
Carbopol 941 manufactured by B. F. Goodrich Co. and the composition does 
not contain any alkali metal hydroxide such as sodium hydroxide or 
potassium hydroxide, wherein the alkali metal silicate exists in the 
composition as a viscoelastic network structure of the alkali metal 
silicate. 
Additionally, such formulations may include up to about 6% wt. of a foam 
booster, a foam stabilizer and a viscosity adjusting agent. 
It has now been found that the problem of removing cooked-on and dried-on 
food residues from ovens can be resolved by applying at a temperature of 
about 25.degree. C. (room temperature) to about 40.degree. C. thereto for 
a relatively short time (10-30 minutes) the shear thickening pre-spotting 
composition of the present invention. 
In accordance with the invention, the removal of cooked-on soils is thus 
effected by: contacting the soiled oven with an effective amount of the 
above-identified shear thickening pre-spotting compositions; allowing an 
effective amount of time (at least about 10 minutes) for the composition 
to soak through the soil; and then rinsing the affected soiled surfaces to 
remove the shear thickening pre-spotting composition and the loosened soil 
,

DETAILED DESCRIPTION OF THE INVENTION 
The shear thickening pre-spotting compositions of this invention are 
comprised of the following components: an alkali metal silicate, 
optionally, at least one surfactant, optionally, an alkanolamine, 
imidazole, water, optionally, a water organic compound having the formula 
C.sub.n H.sub.2n+2-x (OH).sub.x wherein x=1 to 3 and n=1 to 20, and 
optionally a builder. In addition to the above ingredients, the 
compositions of this invention may contain other substances generally 
present in detergent compositions. Foam stabilizing agents may be 
incorporated, and other ingredients which may normally be present include 
preservatives, humectants, foam boosters, anti-foaming agents, 
dispersants, pH modifiers, colorants and perfumes. 
The surfactant, which is optionally present in the composition in the 
amount of about 0 to about 5 wt. %, more preferably 0.1 to 5 weight %, is 
selected from the group consisting of nonionic surfactants, anionic 
surfactants and their combinations. Preferably, the surfactant is present 
in the amount of about 1 to about 5 weight %. 
The nonionic surfactant, preferably, is comprised of one or a mixture of 
primary alcohol ethoxylates or secondary alcohol ethoxylates or alkyl 
phenol ethoxylates. The primary alcohol ethoxylates are represented by the 
general formula: 
EQU R--O--(CH.sub.2 --CH.sub.2 --O).sub.n --H 
wherein R is an alkyl radical having from 9 to 16 carbon atoms and the 
number of ethoxylate groups, n, is from 5 to 12. Commercially available 
nonionic surfactants of this type are sold by Shell Chemical Company under 
the tradename Neodol and by Union Carbide Corporation under the tradename 
Tergitol. 
The secondary alcohol ethoxylates are represented by the general formula: 
##STR1## 
Wherein x+y is from 6 to 15 and the number of ethoxylate groups, n, is from 
5 to 12. Commercially available surfactants of this type are sold by Union 
Carbide Corporation under the tradename Tergitol S series surfactants, 
with Tergitol 15-S-9 (T 15-S-9) being preferred for use herein. 
The alkyl phenol ethoxylates are represented by the general formula: 
EQU R-(phenyl)-O-(CH.sub.2 --CH.sub.2 --O).sub.n --H 
where the number of ethoxylate groups, n, is from 8 to 15, and R is an 
alkyl radical having 8 or 9 carbon atoms. Commercially available nonionic 
surfactants of this type are sold by Rohm and Haas Company under the 
tradenames Triton N and Triton X series. 
The anionic surfactant is preferably comprised of alkali metal salts of 
C.sub.10 -C.sub.20 paraffin sulfonates, C.sub.10 -C.sub.20 alkyl sulfates, 
C.sub.10 -C.sub.20 ethoxylated alkyl ether sulfates, and C.sub.10 
-C.sub.20 alkyl benzene sulfonates, such as sodium linear tridecyl or 
dodecyl benzene sulfonate, sodium and/or ammonium alcohol 3-ethoxy sulfate 
(AEOS), sodium lauroyl, cocoyl or myristoyl sarcosinate or a combination 
thereof. 
Alkylpolysaccharides surfactants which are also useful alone or in 
conjunction with the aforementioned surfactants and have a hydrophobic 
group containing from about 8 to about 20 carbon atoms, preferably from 
about 10 to about 16 carbon atoms, most preferably from 12 to 14 carbon 
atoms, and polysaccharide hydrophilic group containing from about 1.5 to 
about 10, preferably from 1.5 to 4, and most preferably from 1.6 to 2.7 
saccharide units (e.g., galactoside, glucoside, fructoside, glucosyl, 
fructosyl, and/or galactosyl units). Mixtures of saccharide moieties may 
be used in the alkylpolysaccharide surfactants. The number x indicates the 
number of saccharide units in a particular alkylpolysaccharide surfactant. 
For a particular alkylpolysaccharide molecule x can only assume integral 
values. In any physical sample can be characterized by the average value 
of x and this average value can assume non-integral values. In this 
specification the values of x are to be understood to be average values. 
The hydrophobic group (R) can be attached at the 2-, 3-, or 4-positions 
rather than at the I-position, (thus giving e.g. a glucosyl or galactosyl 
as opposed to a glucoside or galactoside). However, attachment through the 
1-position, i.e., glucosides, galactosides, fructosides, etc., is 
preferred. In the preferred product the additional saccharide units are 
predominately attached to the previous saccharide unit's 2-position. 
Attachment through the 3-, 4-, and 6-positions can also occur. Optionally 
and less desirably there can be a polyalkoxide chain joining the 
hydrophobic moiety (R) and the polysaccharide chain, the preferred 
alkoxide moiety is ethoxide. 
Typical hydrophobic groups include alkyl groups, either saturated or 
unsaturated, branched or unbranched containing from about 8 to about 20, 
preferably from about 10 to about 16 carbon atoms. Preferably, the alkyl 
group is a straight chain saturated alkyl group. The alkyl group can 
contain up to 3 hydroxy groups and/or the polyalkoxide chain can contain 
up to about 30, preferably less than 10, most preferably 0, alkoxide 
moieties. 
Suitable alkyl polysaccharides are decyl, dodecyl, tetradecyl, pentadecyl, 
hexadecyl, and octadecyl, di-, tri-, tetra-, penta-, and hexaglucosides, 
galactosides, lactosides, fructosides, fructosyls, lactosyls, glucosyls 
and/or galactosyls and mixtures thereof. 
The alkyl monosaccharides are relatively less soluble in water than the 
higher alkylpolysaccharides. When used in admixture with 
alkylpolysaccharides, the alkylmonosaccharides are solubilized to some 
extent. The use of alkylmonosaccharides in admixture with 
alkylpolysaccharides is a preferred mode of carrying out the invention. 
Suitable mixtures include coconut alkyl, di-, tri-, tetra-, and 
pentaglucosides and tallow alkyl tetra-, penta-, and hexaglucosides. 
The preferred alkylpolysaccharides are alkylpolyglucosides having the 
formula: 
EQU R.sub.2 O(C.sub.n H.sub.2n O).sub.r (Z).sub.x 
wherein Z is derived from glucose, R is a hydrophobic group selected from 
the group consisting of alkyl, alkylphenyl, hydroxyalkylphenyl, and 
mixtures thereof in which said alkyl groups contain from about 10 to about 
18, preferably from 12 to 14 carbon atoms; n is 2 or 3 preferably 2, r is 
from 0 to about 10, preferable 0; and x is from 1.5 to about 8, preferably 
from 1.5 to 4, most preferably from 1.6 to 2.7. To prepare these compounds 
a long chain alcohol (R.sub.2 OH) can be reacted with glucose, in the 
presence of an acid catalyst to form the desired glucoside. Alternatively 
the alkylpolyglucosides can be prepared by a two step procedure in which a 
short chain alcohol (R.sub.1 OH) an be reacted with glucose, in the 
presence of an acid catalyst to form the desired glucoside. Alternatively 
the alkylpolyglucosides can be prepared by a two step procedure in which a 
short chain alcohol (C.sub.1-6) is reacted with glucose or a polyglucoside 
(x=2 to 4) to yield a short chain alkyl glucoside (x=1 to 4) which can in 
turn be reacted with a longer chain alcohol (R.sup.2 OH) to displace the 
short chain alcohol and obtain the desired alkylpolyglucoside. If this two 
step procedure is used, the short chain alkylglucoside content of the 
final alkylpolyglucoside material should be less than 50%, preferably less 
than 10%, more preferably less than 5%, most preferably 0% of the 
alkylpolyglucoside. 
The amount of unreacted alcohol (the free fatty alcohol content) in the 
desired alkylpolysaccharide surfactant is preferably less than about 2%, 
more preferably less than about 0.5% by weight of the total of the 
alkylpolysaccharide. For some uses it is desirable to have the 
alkylmonosaccharide content less than about 10%. 
The used herein, "alkylpolysaccharide surfactant" is intended to represent 
both the preferred glucose and galactose derived surfactants and the less 
preferred alkylpolysaccharide surfactants. Throughout this specification, 
"alkylpolyglucoside" is used to include alkyl- polyglycosides because the 
stereo chemistry of the saccharide moiety is changed during the 
preparation reaction. 
An especially preferred APG glycoside surfactant is APG 625 glycoside 
manufactured by the Henkel Corporation of Ambler, Pa. APG 25 is a nonionic 
alkylpolyglycoside characterized by the formula: 
EQU C.sub.n H.sub.2n+1 O(C.sub.6 H.sub.10 O.sub.5).sub.x.sup.H 
wherein n=10(2%); n=12(65%); n=14(21-28%); n=16(4-8%) and n=18 x(degree of 
polymerization)=1.6. APG 625 has: a pH of 6-8(10% of APG 625 in distilled 
water); a specific gravity at 25.degree. C. of 1.1 grams/ml; a density at 
25.degree. C. of 9.1 kgs/gallons; a calculated HLB of about 12.1 and a 
Brookfield viscosity at 35.degree. C., 21 spindle, 5-10 RPM of about 3,000 
to about 7,000 cps. Mixtures of two or more of the liquid nonionic 
surfactants can be used and in some cases advantages can be obtained by 
the use of such mixtures. 
The composition also contains about 0 to about 10 weight % of a builder 
salt or electrolyte, which is comprised of phosphates, such as 
tetrapotassium pyrophosphate, sodium tripolyphosphate; carbonates, such as 
sodium carbonate, sodium sesquicarbonate and sodium bicarbonate sodium 
gluconate, citrates, such as sodium citrate; and sodium ethylene diamine 
tetraacetate. The preferred amount of the builder in the composition is 
about 0.5 to about 5 weight %. 
The composition contains about 0.1 to about 25 weight %, more preferably 
about 0.1 to about 10 wt. % of a cyclic nitrogen containing compound such 
as pyrrolidine, pyridine, 2 pyrrolidine, N-methyl, 2- pyrrolidine, 
imidazole, morpholine, and diethylenetriamine, wherein the preferred 
cyclic nitrogen containing compounds are imidazole and 4-methylimidazole. 
Imidazole is especially preferred. Triethylenediamine or 1,4-diaza bicylco 
[2,2,2] octane also works in place of the aforementioned cyclic nitrogen 
containing compounds in the instant composition. 
Also present in the composition is 0 to about 4 weight % of an alkanolamine 
selected from the group consisting of monoethanolamine, diethanolamine and 
triethanolamine and mixtures thereof. About 0.1 to about 1.0 weight % of 
the alkanolamine in the composition is preferred. 
The shear thickening characteristics of the instant composition are 
directly attributable to the alkali metal silicate present in the 
composition. The alkali metal silicate interacts with both the 
alkanolamine and the imidazole in the composition thereby imparting shear 
thickening properties to the composition. The instant compositions do not 
contain any polymeric thickener such as crosslinked acrylic acid polymers 
of copolymers. 
The mechanism of thickening is such that electrolyte hydroxy containing 
organic compound, imidazole and/or alkanolamine condenses the alkali metal 
silicate by binding the water to the hydroxy containing organic compound, 
the electrolyte, imidazole or alkanolamine thereby promoting the 
aggregation of the alkali metal silicate into a viscoelastic network 
structure of the alkali metal silicate. 
The alkali metal silicate is present in the composition at a concentration 
of about 5 to about 50 weight %, more preferably about 10 to about 45 
weight % and most preferably about 15 to about 40 weight %. The alkali 
metal silicates are selected from the group consisting of lithium 
silicate, sodium silicate and potassium silicates and mixtures thereof. 
The potassium silicate is characterized by the formula (K.sub.2 O).sub.x 
SiO.sub.2 wherein x&gt;2.10 and the potassium silicate has a water content of 
less than 66 weight %. The sodium silicate is characterized by the formula 
(Na.sub.2 O).sub.y SiO.sub.2 wherein y&gt;2.88 and the sodium silicate has a 
water content of less than 61 weight %. The lithium silicate is 
characterized by formula (Li.sub.2 O)zSiO.sub.2 wherein z&gt;2.1 and the 
lithium silicate has a water content of less than 65 weight %. The alkali 
metal silicates used in the process of making the instant composition are 
in an aqueous solution comprising about 30 wt. % to about 60 wt. % of the 
alkali metal silicate and the balance being water. For example, a 39 wt. % 
aqueous solution of (K.sub.2 O)2.1 SiO.sub.2 was used in Example 1. This 
means that 87.1 grams of the 39% aqueous solution the potassium silicate 
in Example I-A was used to provide 34 wt. % of the potassium silicate. The 
water from the aqueous solution of the potassium silicate is reflected as 
part of water as shown in Examples 1A-1D on the line indicating the wt. % 
of water. 
Water completes the balance of the composition and the pH of the 
composition is about 10 to about 13, preferably about 12 to about 13. 
The compositions of this invention are prepared by adding with stirring in 
a suitable mixer and homogenizer at a temperature of about 15.degree. C. 
to about 30.degree. C. an aqueous solution of imidazole and/or 
alkanolamine to an aqueous solution of the alkali metal silicate selected 
from the group consisting of lithium silicate, sodium silicate and 
potassium silicate, wherein the alkali metal silicate is in an aqueous 
solution at a concentration of about 30 wt. % to about 60 wt. %. The 
resultant composition of the alkali metal silicate, water, cyclic nitrogen 
containing compound such as imidazole and the alkanolamine exhibits 
dilatant characteristics. The viscosity of the resultant compositions for 
a shear rate of 2 radians/second at about room temperature (25.degree. C.) 
as applied for 30 seconds is about 1.0 to about 110 Pa.s and at a shear 
rate of 10 radians/second at about room temperature (25.degree. C.) as 
applied for 30 seconds of about 2 to about 190 Pa.s., wherein the 
viscosity of the composition at a shear rate of 10 radians/second is 
always greater than the viscosity of the same composition at a shear rate 
of 2.0 radians/second for the same composition. When the viscosity is 
plotted against the shear rate for the compositions of the instant 
invention a positive slope is obtained thereby indicating that the instant 
compositions are shear thickening. Upon the application of increasing 
shear rate to an aqueous solution of the composition the aqueous solution 
will shear thicken and an increase in viscosity will occur. The increase 
is independent of the time scale of the experiment. The compositions of 
the prior art exhibit a negative slope thereby showing these compositions 
are non shear thinning--decrease in viscosity. To the shear thickening 
solution of the alkali metal silicate, water, imidazole and alkanolamine 
can be added various ingredients in any order, wherein the order of 
addition is not critical and the addition of these ingredients does not 
destroy the shear thickening property of the composition. The various 
ingredients are added at a temperature of about 15.degree. C. to about 
30.degree. C., with a moderate shear rate of mixing of about 300 to about 
800 rpms. The various ingredients that can be added are the non-soap 
anionic surfactants, the nonionic surfactant and optionally, a builder. 
The addition of these ingredients to the composition of the alkali metal 
silicate, water, imidazole and alkanolamine will not destroy the shear 
thickening characteristics and the final composition will exhibit a 
viscosity at 25.degree. C. of about 1 to about 110 Pa.s at a shear rate of 
2 radian/second at room temperature as applied for 30 seconds and about 2 
to about 190 Pa.s at a shear rate of 10 radians/seconds as applied for 
thirty seconds at room temperature. 
The instant compositions do not contain metal hydroxides; however, the 
instant compositions may optionally contain alkali metal halides such as 
lithium chloride, sodium chloride and potassium chloride in an amount of 
about 0.1 to about 15 weight %, wherein the alkali metal halide will aid 
as a structuring agent as does the cyclic amine for the alkali metal 
silicate. An organic compound having at least one hydroxyl group such as 
propylene glycol or 1,6-hexanediol can be used as a structuring agent for 
the alkali metal silicate. The organic compound having at least one 
hydroxyl group has the formula: 
EQU C.sub.n H.sub.2n+2-x (OH).sub.x 
wherein n is about 1 to about 20, more preferably about 1 to about 10 and 
x=1,2 or 3 and the concentration of the organic compound is about 0 to 
about 30 wt. %, more preferably about 0.1 to about 15.0 wt. %. Also 
suitable as structuring agents are nonionic surfactants containing a 
hydroxyl group. 
The following examples will serve to illustrate the present invention 
without being deemed limitative thereof. Parts and percents are by weight 
unless otherwise indicated. 
EXAMPLE 1 
Formulation of the following ingredients are prepared: 
TABLE I 
__________________________________________________________________________ 
A B C D 
__________________________________________________________________________ 
K.sub.2 O(2.1)ISiO.sub.2.sup.1 
34 33 30 32 
Water 59 60 62.4 60 
Imidazole 5 5 5 5 
Triethanolamine 1 1 1 1 
APG 625.sup.2 1 1 1 1 
LiCl -- -- 0.6 -- 
Propylene Glycol 
-- -- -- 2 
Appearance very thick clear 
thick clear 
thick clear 
thick clear 
Viscosity Pa.s, RT, shear rate 2 
116 2 8.4 1 
radians/second 
Viscosity Pa.s, RT, shear rate 10 
184 2.5 25 1.3 
radians/second 
__________________________________________________________________________ 
1. This was used as 39 wt. % aqueous solution of K.sub.2 O(2.1 ) SiO.sub.2. 
Therefore for example in Example 1A 87.1 grams of the aqueous solution was 
used which yield 34 grams of the K.sub.2 O(2.1 ) SiO.sub.2. This means 
that of the 59 grams of water in 1A that 53.1 grams came from the aqueous 
solution of the K.sub.2 O(2.1) SiO.sub.2. 
2. APG 625 is manufactured by Henkel and is an alkypolyglycoside with 
D.P=1.6 and a hydrophobe chain length of C.sub.12. 
A 39% solution of the potassium silicate and water was prepared. (39 wt. % 
of potassium silicate) with stirring at room temperature for 5 minutes. To 
the (39%) solution of the potassium silicate and water is added with 
stirring at room temperature for 5 minutes an aqueous solution of the 
imidazole triethanolamine and surfactant. 
These formulations were tested on Crisco shortening baked at 350.degree. F. 
for 10 hours on a 2 inch pyrex petri dishes and macaroni cheese for one 
hour at 350.degree. F. Approximately 4 g of each formula was used and the 
soil was soaked at room temperature for 1 hour. The formulations were then 
rinsed off with tap water and light rubbing to remove loosened soil. 
Percent soil removal was determined gravimetrically. Three replicates were 
run for each formula. The results are presented in Table 2. 
TABLE 2 
______________________________________ 
% Soil Removal 
Formula Crisco Shortening 
Macaroni & Cheese 
______________________________________ 
A 37 91 
B 33 88 
C 38 98 
D 32 98 
Formula 409 2 79 
Commercial product 
______________________________________ 
The silicate thickened formulas show superior efficacy on the Crisco 
shortening soil to formula 409 a commercial multi-surface spray cleaner. 
The results for macaroni & cheese are also better than the previous 
prototype and equal to slightly better than formula 409. These formulas do 
not cause damage to aluminum even though the pH is 12.5; however, formula 
409, pH 12.5 does damage aluminum. 
Since these formulas are thickened they will cling to vertical surfaces 
better. These formulas (0.5 g) were applied in a 3 inch line to Aluminum 
sheets and the time for the formula to travel 6 inches after the sheet was 
tilted vertically was measured. The results are shown in Table 3. 
TABLE 3 
______________________________________ 
Vertical Hang Measurements 
Formula # Time for 6 in (sec) 
______________________________________ 
A 1 inch in 14 minutes 
B 2 inches in 15 minutes 
Formula 409 Commercial product 
&lt;1 
______________________________________ 
The silicate thickened formulas have significantly longer vertical hang 
times than formula 409 and comparable in or longer than a previous 
prototype which was thickened with a polyacrylate. These formulas should 
be easier to use and less messy when vertical surfaces need to be cleaned.