FIELD
[0001] This disclosure is directed to a solvent composition for use in cleaning metal components.
More specifically, the composition includes a blend of organic solvents that, while
being exempted from, or not classified as, a volatile organic compound, a hazardous
air pollutant, or a potential carcinogen.
BACKGROUND
[0002] Metal parts cleaners generally fall in to one of two categories: chlorinated solvents
and hydrocarbon solvents. Although chlorinated solvents are non-flammable and are
not classified as a volatile organic compound (VOC), they are generally considered
to be a potential carcinogen and pose an less than acceptable health risk to users.
Hydrocarbon solvents, on the other hand, possess favorable cleaning action and fast
evaporation without residue, however, they have varying serious health risks, including
potential carcinogenic effects. These solvents, such as toluene, benzene, xylene,
and hexane, are classified as a VOC or a hazardous air pollutant (HAP), which limits
their use in commercial settings. It would be beneficial to create a metal parts cleaner
that has the solubility and cleaning action properties of these traditional solvents,
but without the associated health risks to the user.
SUMMARY
[0003] A composition for use in cleaning metal components is disclosed. In one embodiment,
the Hansen Solubility Parameters for the composition are δD ≥ 15, δP < 6, and δH from
about 5.5 to about 6.9. Moreover, the composition includes a blend of organic solvents.
In one embodiment, none of the organic solvents are classified as a volatile organic
compound, a hazardous air pollutant, or a potential carcinogen, or wherein the solvent
exhibits a vapor pressure of less than 0.1 mmHg at 20°C.
[0004] Specifically, the blend of organic solvents may include a halogenated aromatic solvent
having one or more halide groups and from 6 to 8 carbon atoms, wherein the Hansen
Solubility Parameters for the halogenated aromatic solvent are in the range of about
δD : 17 - 19, δP: 5-7, and δH: 3-5; an organic solvent having one or more ester functional
group and from 3 to 9 carbon atoms, wherein the Hansen Solubility Parameters for the
organic solvent are in the range of about δD : 14 - 16, δP: 3.5-7.5, and δH: 5-10;
and one or more of the following: a linear or branched hydrocarbon solvent with 6-12
carbon atoms with a single polar moiety head group, wherein the Hansen Solubility
Parameters for the hydrocarbon solvent are in the range of about δD : 6-9, δP: 1-3,
and δH: 5-7; and a solvent containing one or more ketone functional groups and from
2 to 5 carbon atoms, wherein the Hansen Solubility Parameters for the solvent containing
one or more ketone functional groups are in the range of about δD : 14-16, δP: 8.5
- 11, and δH: 5-8.
[0005] In one embodiment, the halogenated aromatic solvent is parachlorobenzotriflouride
which is present in an amount from about 0.25% to about 20% of the composition.
[0006] In another embodiment, the organic solvent with one or more ester functional groups
is selected from the group consisting of tert-butyl acetate, methyl acetate, dimethyl
carbonate, diethylene glycol monoethyl acetate, and diethylene glycol monobutyl ether
acetate. In yet another embodiment, the organic solvent with one or more ester functional
groups is tert-butyl acetate which is present in an amount from about 25% to about
65% of the composition.
[0007] In another embodiment, the hydrocarbon solvent having a single polar moiety head
group is 1-butoxyhexanol or 2-ethyl-hexanol which is present in an amount from about
0.1% to about 1% of the composition.
[0008] In another embodiment, the solvent containing one or more ketone functional groups
is acetone which is present in an amount from about 5% to about 50% of the composition.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying figures, which are incorporated in and constitute a part of the
specification, illustrate various example configurations and data, and are used merely
to illustrate various example embodiments. In the figures, like elements bear like
reference numerals.
[0010] Figure 1 is the graphical representation of evaporation curves for various example
formulations.
DETAILED DESCRIPTION
[0011] A composition for use in cleaning metal parts is provided. Specifically the composition
includes a blend of organic solvents. In one embodiment, the blend includes one or
more organic solvent, each of which are either 1) not classified as, or are exempt
from being classified as, a VOC, a HAP, or a potential carcinogen or 2) have a vapor
pressure of less than 0.1 mmHg at 20°C. Surprisingly, it has been found that this
blend of organic solvents exhibits a cleaning action, solubility parameters, and evaporation
rates (leading to decreased residue on the component) that are comparable to solvents
considered to pose potential health risks.
[0012] Although none of the components of the blended composition are classified (or are
exempt from being classified) as a VOC, HAP, or potential carcinogen, the resulting
composition exhibits Hansen Solubility Parameters that are similar to those substances.
Specifically, the Hansen Solubility Parameters for the blended composition have been
found to be δ
D ≥ 14-16, δ
P < 3.5 - 7, and δ
H from about 5.5 to about 6.9.
[0013] In one embodiment, the composition is created by combining a halogenated aromatic
solvent having one or more halide groups and from 6 to 8 carbon atoms, an organic
solvent having one or more ester functional groups and from 3 to 9 carbon atoms, and
one or more of a linear or branched hydrocarbon solvent with 6-12 carbon atoms with
a single polar moiety head group and a solvent containing one or more ketone functional
groups and from 2 to 5 carbon atoms.
[0014] In one embodiment, the halogenated aromatic solvent having one or more halide groups
and from 6 to 8 carbon atoms has Hansen Solubility Parameters that are in the range
of about δD : 17 - 19, δP: 5-7, and δH: 3-5 and is present in the composition in an
amount of from 0.25% to 20%, and preferably from about 1% to about 9%, of the total
composition. Further, it should be understood that these halogenated aromatic solvents
are not considered a HAP or potential carcinogen and are exempted from VOC, or they
exhibit a vapor pressure of less than about 0.1 mmHg at 20°C. In one embodiment, the
halogenated aromatic solvent is parachlorobenzotriflouride (PCBTF).
[0015] In another embodiment, the organic solvent having one or more ester functional group
and from 3 to 9 carbon atoms has Hansen Solubility Parameters that are in the range
of about δD : 14 - 16, δP: 3.5-7.5, and δH: 5-10 and is present in the composition
in an amount from about 25% to about 65% of the total composition. Further, it should
be understood that these ester-containing organic solvents are not considered a HAP
or potential carcinogen and are exempted from VOC, or they exhibit a vapor pressure
of less than about 0.1 mmHg at 20°C. In one embodiment the ester-containing organic
solvent may be methyl acetate, dimethyl carbonate, diethylene glycol monoethyl ether/diethylene
glycol monobutyl ether acetate (commercially available from Eastman Chemical Company),
t-butyl acetate. In another embodiment, the solvent is t-butyl acetate.
[0016] In another embodiment the linear or branched hydrocarbon solvent with 6-12 carbon
atoms and a single polar moiety head group has Hansen Solubility Parameters that are
in the range of about δD : 6-9, δP: 1-3, and δH: 5-7 and when present in the composition,
is present in the amount of about 0.1 to about 1.2%, and in another embodiment from
about 0.1 to about 1.0%. Further, it should be understood that these linear or branched
hydrocarbon solvents are not considered a HAP or potential carcinogen and are exempted
from VOC, or they exhibit a vapor pressure of less than about 0.1 mmHg at 20°C. In
one embodiment, the hydrocarbon solvent is 2-butoxyhexanol or 2-ethylhexanol. In another
embodiment, the hydrocarbon solvent is 2-ethylhexanol.
[0017] These medium chain length organic solvents may function as a surfactant, lowering
the surface tension between the product and the soiled surfaces. Moreover, the organic
solvents have been found to enhance the composition's wetting action, and thus, its
cleaning ability without leaving a residue or adversely affecting the drying rate.
[0018] In another embodiment, the solvent containing one or more ketone functional groups
and from 2 to 5 carbon atoms has Hansen Solubility Parameters that are in the range
of about δD : 14-16, δP: 8.5 - 11, and δH: 5-8 and when present in the composition,
is present in an amount of about 5% to about 50%. Further, it should be understood
that these solvents are not considered a HAP or potential carcinogen and are exempted
from VOC, or they exhibit a vapor pressure of less than about 0.1 mmHg at 20°C. In
one embodiment, the solvent containing one or more ketone functional group is acetone.
It has been found that the addition of a solvent, such as acetone, enhances the evaporation
rate of the blended composition.
Examples
Solvent Effect - Varied Soils
[0019] Individual solvents were evaluated by visual inspection of solvation action when
applied to various soils encountered in automotive cleaning procedures. The soils
used for testing included 10W-30 motor oil, DOT 3 brake fluid, #2 Lithium Grease,
and Power Steering Fluid. Solvation was evaluated on a relative scale: Poor, Fair,
Good and Excellent. The rating is based on the solvent's ability to blend with the
soil of interest, the rate of the blending, the amount of solvent required to remove
the soil from the substrate and the amount of residue left behind by the solvent.
Test Procedure
[0020] In one example, the individual solvents were evaluated. Aluminum test dishes were
prepared by applying approximately 5 drops of each soil to the dishes. Neat solvent
was added dropwise beside each soil so that the edges of the two materials came in
contact with one another. The solvation action of the solvent was observed. The extent
to which the soil and the solvent mixed and the rate of mixing was observed. Additional
solvent was then applied to each section and the dish was lifted to observe the removal
of the soil. Another addition of solvent was applied by pipette (approx. 1-2 mL) to
observe the spray-off characteristics of each soil/solvent combination.
Relative Solvation Rating Standards - Table 1
Rating |
Explanation |
Poor |
Little or no solvation. Very slow rate of solvation. Large amount of soil residue
after spray. |
Fair |
Some, slow solvation effect. Slow to Moderate solvation rate. Moderate amount of soil
residue after spray. |
Good |
Significant solvation effect. Moderate to rapid solvation rate. Small amount of residue
after spray. |
Excellent |
Significant solvation effect. Rapid/extensive solvation rate. No soil residue after
spray. |
[0021] The results of the Hansen Solubility calculations and evaporation rate data are shown
below in Table 2:
Table 2
|
|
Hansen Data |
|
Solvents |
VOC |
dD |
dP |
dH |
MVol |
Evaporation Rate (BuAc = 1) |
Toluene |
Yes |
18 |
1.4 |
2 |
106.6 |
1.9 |
Xylene |
Yes |
17.6 |
1 |
3.1 |
123.9 |
0.6 |
Heptane |
Yes |
15.3 |
0 |
0 |
147 |
4.3 |
Eastman EEH |
No |
7.8 |
2 |
2.5 |
195.9 |
0.003 |
2-ethyl hexanol |
No |
7.8 |
1.6 |
5.8 |
123.9 |
< 0.01 |
dibasic ester LVP |
No |
8.3 |
2.2 |
0 |
151.21 |
0.009 |
Dowanol Eph |
No |
17.8 |
5.7 |
14.3 |
124.5 |
0.001 |
Eastman Omnia |
No |
7.87 |
3.13 |
5.62 |
164.99 |
0.01 |
Eastman DE Acetate |
No |
7.9 |
2.5 |
4.5 |
174.12 |
0.008 |
Eastman DB Acetate |
No |
7.8 |
3.4 |
5.2 |
208.44 |
0.003 |
Eastman DP Solvent |
No |
7.8 |
3.5 |
5.5 |
152.78 |
0.01 |
Eastman Texanol |
No |
7.8 |
3.5 |
5.5 |
152.78 |
0.002 |
Acetone |
No |
15.5 |
10.4 |
7 |
73.8 |
14.4 |
PCBTF |
No |
18 |
5.9 |
3.9 |
134.75 |
0.9 |
t-butyl acetate |
No |
15 |
3.7 |
6 |
132.6 |
2.8 |
dimethyl carbonate |
No |
8.5 |
4.7 |
1.9 |
84.2 |
3.22 |
Carbitol Solvent |
No |
16.1 |
9.2 |
12.2 |
135.56 |
0.01 |
Methyl Acetate |
No |
15.5 |
7.2 |
7.6 |
79.8 |
6 |
Propylene Carbonate |
No |
20 |
18 |
4.1 |
85.2 |
0.005 |
[0022] The results of the Solvent Effect data for various soils are shown below in Table
3:
Table 3
|
|
Solvent Effect - Varied Soils |
Solvents |
VOC |
Motor Oil |
Brake Fluid |
Power Steering Fluid |
Greases |
Toluene |
Yes |
Excellent |
Good |
Good |
Good |
Xylene |
Yes |
Excellent |
Good |
Good |
Good |
Heptane |
Yes |
Excellent |
Good |
Good |
Good |
Eastman EEH |
No |
Good |
Good |
Fair |
Fair |
2-ethyl hexanol |
No |
Good |
Fair |
Poor |
Excellent |
dibasic ester LVP |
No |
Poor/Fair |
Poor |
Poor/Fair |
Good |
Dowanol Eph |
No |
Good |
Excellent |
Good |
Fair |
Eastman Omnia |
No |
Good |
Good |
Good |
Poor/Fair |
Eastman DE Acetate |
No |
Fair/Good |
Good |
Fair/Good |
Poor |
Eastman DB Acetate |
No |
Fair/Good |
Good |
Fair/Good |
Poor |
Eastman DP Solvent |
No |
Fair/Good |
Good |
Fair/Good |
Poor |
Eastman Texanol |
No |
Good |
Fair/Good |
Good |
Poor |
Acetone |
No |
Poor |
Good |
Excellent |
Poor |
PCBTF |
No |
Excellent |
Excellent |
Fair |
Fair |
t-butyl acetate |
No |
Excellent |
Excellent |
Fair |
Fair |
dimethyl carbonate |
No |
Poor |
Good |
Good |
Poor |
Carbitol Solvent |
No |
Fair/Good |
Good |
Good |
Poor |
Methyl Acetate |
No |
Fair/Good |
Excellent |
Good |
Poor |
Propylene Carbonate |
No |
Fair |
Fair/Good |
Good |
Poor |
[0023] Solvation in this context can be readily characterized by example. "No solvation"
can be described by two materials that will not blend in any proportions, i.e. oil
and water. For example, if a drop of oil and a drop of water are placed beside each
other with edges touching, they will not blend and thus have no solvation. The opposite,
and thus "excellent solvation," would be two materials that are miscible and will
blend in any proportion. One example would be water and ethanol. If a drop of each
were placed beside one another, with edges touching, the two would rapidly blend together
and form a homogenous phase. Most materials have some degree of solubility with each
other. The relative scale used above describes this, but also includes an observation
of the rate at which it occurs. Excellent is near instantaneous. Good occurs over
1-3 seconds. Fair is over 5-20 seconds and poor requires significant time to solvate
30 seconds to several minutes. Similar quantification methods were used for the solvent
blend tests, described below.
Solvent Blend Effects - Application Testing on Varied Soils
[0024] In one example, the solvent blends were evaluated by visual inspection of their solvation
action when applied to various soils encountered in automotive cleaning procedures.
The soils used for testing were 10W-30 motor oil, DOT 3 brake fluid, #2 Lithium Grease,
and Power Steering Fluid. Solvation was evaluated on a relative scale: Poor, Fair,
Good and Excellent. The rating is based on the solvent blends ability to remove various
soils from test panels. The effect is bracketed by the performance of the 10% VOC
Parts cleaner on the low end and by the 45% VOC Parts Cleaner on the upper end and
characterizes the solvent blend's ability to blend with the soil of interest, the
rate of the blending, the amount of solvent blend required to remove the soil from
the substrate, and the amount of residue left behind by the solvent.
Test Procedure
[0025] Steel test panels were prepared by the following method. A thin film of NLGI #2 lithium
complex grease, polyurea grease, and calcium sulfonate grease were applied to the
steel test panels in sections with a rag. Approximately 3-5 mL of 10w-30 conventional
motor oil, DOT 3 brake fluid, and power steering fluid were then applied in small
puddles and smeared with a rag or paper towel. The panels were then baked at 60 °C
for approximately 16 hours to simulate service conditions.
[0026] Once the panels were prepared, the individual solvent blends were prepared by mixing
together the individual components in a glass beaker and then stirring the blends
for 1-2 minutes. About 200 g of the blends were then charged into standard 12 oz aerosol
cans. The cans were then pressurized to approximately 100 PSI with CO
2, shaken well, and allowed to sit at least two hours to ensure CO
2 dissolution.
[0027] The individual solvent blends were then tested by the following method. Performance
of test blends were compared to the Valvoline Professional Series (VPS) 10% VOC Parts
Cleaner (commercially available from Valvoline LLC), for a low performance mark, and
the VPS 45% VOC Parts Cleaner (commercially available from Valvoline LLC), for a high-performance
mark. In a well-ventilated area or fume hood, the prepared panels were positioned
above a catch pan. The test blends were then sprayed onto the soils in 2-3 second
bursts, targeting each soil type individually. Each test blend was allowed to penetrate
the soils for approximately 5-10 seconds. The test blends were then sprayed onto the
soils again, targeting each soil type individually for an additional 2-3 second burst.
[0028] The cleaning performance was inspected visually between the first and second burst
and after the panel was allowed to dry. They were evaluated by the same relative rating
standards as above.
[0029] The compositions of the sample solvent blends are set forth in Table 4 below:
Table 4
Sample # |
Acetone |
t-butyl acetate |
PCBTF |
2-ethylhexanol |
Eastman EEH |
1 |
50 |
25 |
25 |
0 |
0 |
2 |
75 |
12.5 |
12.5 |
0 |
0 |
3 |
90 |
5 |
5 |
0 |
0 |
4 |
50 |
50 |
0 |
0 |
0 |
5 |
75 |
25 |
0 |
0 |
0 |
6 |
90 |
10 |
0 |
0 |
0 |
7 |
50 |
0 |
50 |
0 |
0 |
8 |
75 |
0 |
25 |
0 |
0 |
9 |
90 |
0 |
10 |
0 |
0 |
10 |
80 |
10 |
10 |
0 |
0 |
11 |
80 |
15 |
5 |
0 |
0 |
12 |
80 |
5 |
15 |
0 |
0 |
13 |
75 |
15 |
10 |
0 |
0 |
14 |
75 |
20 |
5 |
0 |
0 |
15 |
75 |
10 |
15 |
0 |
0 |
16 |
65 |
35 |
0 |
0 |
0 |
17 |
65 |
25 |
10 |
0 |
0 |
18 |
65 |
30 |
5 |
0 |
0 |
19 |
50 |
40 |
10 |
0 |
0 |
20 |
50 |
45 |
5 |
0 |
0 |
21 |
25 |
65 |
10 |
0 |
0 |
22 |
0 |
85 |
15 |
0 |
0 |
23 |
65 |
32.5 |
2.5 |
0 |
0 |
24 |
50 |
0 |
0 |
50 |
0 |
25 |
75 |
0 |
0 |
25 |
0 |
26 |
65 |
0 |
0 |
35 |
0 |
27 |
90 |
0 |
0 |
10 |
0 |
28 |
0 |
50 |
0 |
50 |
0 |
29 |
0 |
65 |
0 |
35 |
0 |
30 |
0 |
75 |
0 |
25 |
0 |
31 |
0 |
90 |
0 |
10 |
0 |
32 |
65 |
0 |
0 |
0 |
35 |
33 |
75 |
0 |
0 |
0 |
25 |
34 |
90 |
0 |
0 |
0 |
10 |
35 |
0 |
65 |
0 |
0 |
35 |
36 |
0 |
75 |
0 |
0 |
25 |
37 |
0 |
90 |
0 |
0 |
10 |
38 |
50 |
45 |
2.5 |
2.5 |
0 |
39 |
50 |
45 |
4 |
1 |
0 |
40 |
50 |
40 |
9 |
1 |
0 |
41 |
50 |
40 |
0 |
10 |
0 |
42 |
50 |
45 |
0 |
5 |
0 |
43 |
50 |
40 |
5 |
5 |
0 |
44 |
0 |
90 |
5 |
5 |
0 |
45 |
0 |
90 |
9 |
1 |
0 |
46 |
29 |
65 |
5 |
1 |
0 |
47 |
0 |
95 |
4 |
1 |
0 |
48 |
29 |
67.5 |
2.5 |
1 |
0 |
49 |
0 |
96.5 |
2.5 |
1 |
0 |
[0030] The Hansen Solubility Parameters were calculated for each sample. The data from those
calculations are provided below in Table 5.
Table 5
Sample # |
Hansen Solubility Parameters |
|
dD |
dP |
dH |
1 |
13.8 |
6.9 |
5.5 |
2 |
15.8 |
9.0 |
6.5 |
3 |
15.6 |
9.84 |
6.795 |
4 |
15.25 |
7.05 |
6.5 |
5 |
15.375 |
8.725 |
6.75 |
6 |
15.45 |
9.73 |
6.9 |
7 |
16.75 |
8.15 |
5.45 |
8 |
16.125 |
9.275 |
6.225 |
9 |
15.75 |
9.95 |
6.69 |
10 |
15.7 |
9.28 |
6.59 |
11 |
15.55 |
9.17 |
6.695 |
12 |
15.85 |
9.39 |
6.485 |
13 |
15.675 |
8.945 |
6.54 |
14 |
15.525 |
8.835 |
6.645 |
15 |
15.825 |
9.055 |
6.435 |
16 |
15.325 |
8.055 |
6.65 |
17 |
15.625 |
8.275 |
6.44 |
18 |
15.475 |
8.165 |
6.545 |
19 |
15.55 |
7.27 |
6.29 |
20 |
15.4 |
7.16 |
6.395 |
21 |
15.425 |
5.595 |
6.04 |
22 |
15.45 |
4.03 |
5.685 |
23 |
15.4 |
8.11 |
6.5975 |
24 |
11.65 |
6 |
6.4 |
25 |
13.575 |
8.2 |
6.7 |
26 |
12.805 |
7.32 |
6.58 |
27 |
14.73 |
9.52 |
6.88 |
28 |
11.4 |
2.65 |
5.9 |
29 |
12.48 |
2.965 |
5.93 |
30 |
13.2 |
3.175 |
5.95 |
31 |
14.28 |
3.49 |
5.98 |
32 |
12.805 |
7.46 |
5.425 |
33 |
13.575 |
8.3 |
5.875 |
34 |
14.73 |
9.56 |
6.55 |
35 |
12.48 |
3.105 |
4.775 |
36 |
13.2 |
3.275 |
5.125 |
37 |
14.28 |
3.53 |
5.65 |
38 |
15.145 |
7.0525 |
6.4425 |
39 |
15.298 |
7.117 |
6.414 |
40 |
15.448 |
7.227 |
6.309 |
41 |
14.53 |
6.84 |
6.48 |
42 |
14.89 |
6.945 |
6.49 |
43 |
15.04 |
7.055 |
6.385 |
44 |
14.79 |
3.705 |
5.885 |
45 |
15.198 |
3.877 |
5.809 |
46 |
15.223 |
5.732 |
6.183 |
47 |
15.048 |
3.767 |
5.914 |
48 |
15.148 |
5.677 |
6.2355 |
49 |
15.003 |
3.734 |
5.9455 |
[0031] The results of the solvent removal data are set forth in Table 6, below.
Table 6
Sample # |
Observations (based on a summary of all soils used) |
|
Solvency |
Soil Removal |
Evaporation Rate |
Residue |
1 |
Fair |
Fair |
Fair (slow) |
Significant |
2 |
Fair |
Poor |
Fair |
Extensive |
3 |
Poor |
Poor |
Too fast |
Extensive |
4 |
Fair |
Good |
Fair |
Significant |
5 |
Fair |
Fair |
- |
Significant |
6 |
Poor |
Poor |
Too fast |
Extensive |
7 |
Good |
Good |
Too slow |
Significant |
8 |
Fair |
Good |
Too slow |
Significant |
9 |
Poor |
Fair |
Fair |
Extensive |
10 |
Fair |
Fair |
Fair |
Extensive |
11 |
Fair |
Fair |
Fair |
Extensive |
12 |
Fair |
Fair |
Too slow |
Extensive |
13 |
Fair |
Good |
Fair |
Significant |
14 |
Good |
Good |
Fair |
Significant |
15 |
Fair |
Good |
Too slow |
Significant |
16 |
Good |
Fair |
Fair |
Minimal |
17 |
Good |
Good |
Good |
Minimal |
18 |
Good |
Good |
Good |
Minimal |
19 |
Excellent |
Good |
Good |
Minimal |
20 |
Excellent |
Good |
Good |
Minimal |
21 |
Excellent |
Good |
Fair |
None |
22 |
Excellent |
Good |
Fair |
None |
23 |
Good |
Fair |
Good |
Significant |
24 |
Poor |
Fair |
Too slow |
Extensive |
25 |
Fair |
Fair |
Too slow |
Extensive |
26 |
Fair |
Good |
Too slow |
Significant |
27 |
Poor |
Fair |
Too slow |
Extensive |
28 |
Fair |
Good |
Too slow |
None |
29 |
Good |
Good |
Too slow |
None |
30 |
Good |
Good |
Too slow |
None |
31 |
Excellent |
Excellent |
Too slow |
None |
32 |
Fair |
Good |
Too slow |
Significant |
33 |
Fair |
Good |
Too slow |
Significant |
34 |
Poor |
Poor |
Fair |
Significant |
35 |
Good |
Good |
Too slow |
None |
36 |
Good |
Good |
Too slow |
None |
37 |
Excellent |
Excellent |
Fair |
None |
38 |
Good |
Good |
Fair |
Minimal |
39 |
Good |
Good |
Good |
Minimal |
40 |
Good |
Good |
Good |
Minimal |
41 |
Good |
Excellent |
Too slow |
Significant |
42 |
Good |
Excellent |
Too slow |
Significant |
43 |
Good |
Excellent |
Too slow |
Significant |
44 |
Excellent |
Excellent |
Poor |
None |
45 |
Excellent |
Excellent |
Good |
None |
46 |
Excellent |
Excellent |
Good |
None |
47 |
Excellent |
Excellent |
Fair |
None |
48 |
Excellent |
Excellent |
Excellent |
None |
49 |
Excellent |
Excellent |
Good |
None |
[0032] It will be understood that if a composition has an evaporation rate that is deemed
to be "too slow," the solvent composition can be observed to linger on the cleaning
surface or area around it for a significant amount of time (approximately 5 to about
10 minutes). If an evaporation rate is too slow, one would have to clean the soiled
surface by another means (rag/paper towel, etc.) before continuing work.
[0033] Conversely, if a composition has an evaporation rate that is considered to be "too
fast," the solvent composition does not dwell long enough on the soiled surface to
either solvate the soil completely or facilitate its transport from the surface being
cleaned. This results in having to use more product to transport the soil from the
surface of the component being cleaned and can result in significant residue as well.
[0034] As can be seen from the data above, blended compositions that include about 25 to
30% acetone, about 97 to 65% t-butyl acetate, about 2.5 to about 5% PCBTF, and about
1% 2-ethylhexanol produce high quality cleaning composition, without the expected
health risks generally associated with known metal parts cleaners. In one embodiment,
the blended composition will preferably include about 29% acetone, about 67.5% t-butyl
acetate, about 2.5% PCBTF, and about 1% 2-ethylhexanol, as in Sample #48..
[0035] There seems to be a strong relation between soil removal efficiency and the evaporation
rate of the composition, with slow evaporation rates favoring improved soil removal.
Moreover, while large amounts of 2-ethylhexanol appeared to negatively impact the
evaporation rate of the overall composition, small amounts, that is less than about
2.5% of the total weight percent of the blend, appear to improve the wetting action
of the other solvents and helped to improve the soil removal action of the blended
composition. While not being bound to theory, it is believed that the presence of
a small amount of 2-ethylhexanol reduces the evaporation rate of the composition enough
to allow for thorough penetration of persistent soils, thus reducing the amount of
blended composition required to achieve acceptable soil removal.
[0036] To that end, the evaporation rates of examples formulations were compared. Approximately
3 grams of each sample were weighed onto a 3 inch watch glass and left exposed in
a fume hood at a face velocity of 109 feet per minute (FPM). The weight change of
each sample was recorded as a function of time over approximately 15 - 17. As shown
in Figure 1, this data was then plotted by weight change per minute. With continuing
reference to Figure 1, it was found that the methyl acetate and PCBTF formula, lost
nearly 85% of its weight in only 16 minutes. Sample #48, however, performed much better,
losing only about 67.7%, while the toluene composition lost only 41.5% weight. The
optimized evaporation rate of Sample #48 allow the formulations to remain on the soil
for longer periods of time, increasing the soil removal capability, while minimizing
the residue left behind.
[0037] In addition, the data shows that small amounts of PCBTF, from about 2.0% to about
20%, appears to have a synergistic solvation effect with acetone and t-butyl acetate.
It is likely that the presence of an aromatic moiety and a chlorinated/fluorinated
functionality contributes to this effect.
[0038] Finally, the data shows that the ability to control the evaporation rate has a large
impact on the blended composition's overall performance. Preferably, a "stepwise"
evaporation curve, with components in increasingly small amounts, with increasingly
slower evaporation rates allows for soil penetration, but prevents a significant amount
of residual cleaner from remaining on the soiled component part. This will ultimately
improve the performance of the blended composition and reduce the amount needed.
[0039] While the invention has been described with respect to specific examples including
presently preferred modes of carrying out the invention, those skilled in the art
will appreciate that there are numerous variations and permutations of the above described
systems and techniques that fall within the spirit and scope of the invention as set
forth in the appended claims.
[0040] The invention is further drawn to the following embodiments ("embs"):
Emb 1. A composition for use in cleaning metal components, wherein the Hansen Solubility
Parameters for the composition are δD from about 12.0 to about 16.0, δP from about 3.0 to about 10.0, and δH from about 4.0 to about 6.9, and wherein the composition comprises a blend of organic
solvents, wherein either none of the solvents are classified as a volatile organic
compound, a hazardous air pollutant, or a potential carcinogen, or wherein the solvent
exhibits a vapor pressure of less than 0.1 mmHg at 20°C, wherein the blend of organic
solvents comprises:
a halogenated aromatic solvent having one or more halide groups and from 6 to 8 carbon
atoms, wherein the Hansen Solubility Parameters for the halogenated aromatic solvent
are in the range of about δD : 17 - 19, δP: 5-7, and δH: 3-5;
an organic solvent having one or more ester functional group and from 3 to 9 carbon
atoms, wherein the Hansen Solubility Parameters for the organic solvent are in the
range of about δD : 14 - 16, δP: 3.5-7.5, and δH: 5-10; and one or more of the following:
a linear or branched hydrocarbon solvent with 6-12 carbon atoms with a single polar
moiety head group, wherein the Hansen Solubility Parameters for the hydrocarbon solvent
are in the range of about δD : 6-9, δP: 1-3, and δH: 5-7; and
a solvent containing one or more ketone functional groups and from 2 to 5 carbon atoms,
wherein the Hansen Solubility Parameters for the solvent containing one or more ketone
functional groups are in the range of about δD : 14-16, δP: 8.5 - 11, and δH: 5-8.
Emb 2. The composition of Emb 1, wherein the halogenated aromatic solvent is parachlorobenzotriflouride,
and wherein the parachlorobenzotriblouride is present in an amount from about 0.25%
to about 20% of the composition.
Emb 3. The composition of Emb 1, wherein the organic solvent with one or more ester
functional groups is selected from the group consisting of tert-butyl acetate, methyl
acetate, dimethyl carbonate, diethylene glycol monoethyl acetate, and diethylene glycol
monobutyl ether acetate.
Emb 4. The composition of Emb 3, wherein the organic solvent with one or more ester
functional groups is tert-butyl acetate, and wherein the tert-butyl acetate is present
in an amount from about 15% to about 95% of the composition.
Emb 5. The composition of Emb 1, wherein the hydrocarbon solvent having a single polar
moiety head group is 1-butoxyhexanol or 2-ethyl-hexanol, and wherein the hydrocarbon
solvent is present in an amount from about 0.1% to about 2.5% of the composition.
Emb 6. The composition of Emb 1, wherein the solvent containing one or more ketone
functional groups is acetone, and where in the acetone is present in an amount from
about 5% to about 75% of the composition.
Emb 7. The composition of Emb 6, wherein the organic solvent with one or more ester
functional groups is selected from the group consisting of tert-butyl acetate, methyl
acetate, dimethyl carbonate, diethylene glycol monoethyl acetate, and diethylene glycol
monobutyl ether acetate.
Emb 8. The composition of Emb 7, wherein the organic solvent with one or more ester
functional groups is tert-butyl acetate.
Emb 9. The composition of Emb 6, wherein the composition further comprises a hydrocarbon
solvent having a single polar moiety head group, and wherein the hydrocarbon solvent
is 1-butoxyhexanol or 2-ethyl-hexanol.
Emb 10. A composition for use in cleaning metal components, wherein the Hansen Solubility
Parameters for the composition are δD ≥ 15, δP < 6, and δH from about 5.5 to about 6.9, and wherein the composition comprises a blend of organic
solvents, and wherein either none of the solvents are classified as a volatile organic
compound, a hazardous air pollutant, or Potential Carcinogen, or wherein the organic
solvent exhibits a vapor pressure of less than 0.1 mmHg at 20°C, the blend of organic
solvents comprising:
from about 1% to about 9% parachlorobenzotriflouride; and from about 25% to about
70% tert-butyl acetate; and one or more of the following:
from about 0.1 to about 1% 2-ethylhexanol, and
from about 5% to about 75% acetone.
Emb 11. The composition of Emb 10, wherein the composition comprises both 2-ethylexanol
and acetone.
Emb 12. The composition of Emb 11, wherein the composition comprises about 25% to
about 29% acetone, about 65% to about 67.5% t-butyl acetate, about 1% to about 2.5%
PCBTF, and about 1% 2-ethylhexanol.
1. A composition for use in cleaning metal components, wherein the Hansen Solubility
Parameters for the composition are δ
D from about 12.0 to about 16.0, δ
P from about 3.0 to about 10.0, and δ
H from about 4.0 to about 6.9, and wherein the composition comprises a blend of organic
solvents, wherein either none of the solvents are classified as a volatile organic
compound, a hazardous air pollutant, or a potential carcinogen, or wherein the solvent
exhibits a vapor pressure of less than 0.1 mmHg at 20°C, wherein the blend of organic
solvents comprises:
a halogenated aromatic solvent having one or more halide groups and from 6 to 8 carbon
atoms, wherein the Hansen Solubility Parameters for the halogenated aromatic solvent
are in the range of about δD : 17 - 19, δP: 5-7, and δH: 3-5 and wherein the halogenated aromatic solvent is not parachlorobenzotriflouride
(PCBTF);
an organic solvent having one or more ester functional group and from 3 to 9 carbon
atoms, wherein the Hansen Solubility Parameters for the organic solvent are in the
range of about δD : 14 - 16, δP: 3.5-7.5, and δH: 5-10; and one or more of the following:
a linear or branched hydrocarbon solvent with 6-12 carbon atoms with a single polar
moiety head group, wherein the Hansen Solubility Parameters for the hydrocarbon solvent
are in the range of about δD : 6-9, δP: 1-3, and δH: 5-7; and
a solvent containing one or more ketone functional groups and from 2 to 5 carbon atoms,
wherein the Hansen Solubility Parameters for the solvent containing one or more ketone
functional groups are in the range of about δD : 14-16, δP: 8.5 - 11, and δH: 5-8.
2. The composition of claim 1, wherein the organic solvent with one or more ester functional
groups is selected from the group consisting of tert-butyl acetate, methyl acetate,
dimethyl carbonate, diethylene glycol monoethyl acetate, and diethylene glycol monobutyl
ether acetate.
3. The composition of claim 2, wherein the organic solvent with one or more ester functional
groups is tert-butyl acetate, and wherein the tert-butyl acetate is present in an
amount from about 15% to about 95% of the composition.
4. The composition of claim 1, wherein the hydrocarbon solvent having a single polar
moiety head group is 1-butoxyhexanol or 2-ethyl-hexanol, and wherein the hydrocarbon
solvent is present in an amount from about 0.1% to about 2.5% of the composition.
5. The composition of claim 1, wherein the solvent containing one or more ketone functional
groups is acetone, and where in the acetone is present in an amount from about 5%
to about 75% of the composition.
6. The composition of claim 5, wherein the organic solvent with one or more ester functional
groups is selected from the group consisting of tert-butyl acetate, methyl acetate,
dimethyl carbonate, diethylene glycol monoethyl acetate, and diethylene glycol monobutyl
ether acetate.
7. The composition of claim 6, wherein the organic solvent with one or more ester functional
groups is tert-butyl acetate.
8. The composition of claim 5, wherein the composition further comprises a hydrocarbon
solvent having a single polar moiety head group, and wherein the hydrocarbon solvent
is 1-butoxyhexanol or 2-ethyl-hexanol.