Note: Descriptions are shown in the official language in which they were submitted.
NANO-CLEANERS FOR METALWORKING USES
FIELD OF THE INVENTION
This present invention relates to compositions useful for cleaning metal
surfaces, more specifically,
the invention relates to emulsion-containing compositions which, in addition
to cleaning the surface of
metals when applied thereto, also have other desirable properties which make
them highly useful for
industrial metal-working applications.
BACKGROUND OF THE INVENTION
Metalworking Fluids (MWFs) is the name given to various oil or water-based
fluids which are used
to cool and/or lubricate metal workpieces when they are being machined,
ground, milled, etc. These fluids
have a range of application which include: reducing the heat and friction
between the cutting tool and the
workpiece, and preventing burning and smoking during machining of metal parts.
The need to clean the
surface of metals subsequent to various metal working operations is well
known. Using metalworking
fluids also helps improve the machining of workpieces by helping in removing
the fines and chips from the
tool being used and the surface of the workpiece.
While there are many different components and additives in metalworking
fluids, there are four
basic classes as follows: straight oils; soluble oils (emulsifiable oils);
semi-synthetic fluids; and
synthetic fluids. Straight oils are also referred to as "cutting" or "neat"
oils. They are mainly composed of
mineral (petroleum), animal, marine, vegetable or synthetic oils. These oils
are not diluted with water but
other additives may be present. Soluble oils also referred to as emulsifiable
oils contain generally between
30 to 85 percent of refined petroleum oils along with other additives such as
emulsifiers to disperse the oil
in water. Semi-synthetic fluids contain between 5 to 30 percent of severely
refined petroleum oils, 30 to
50 percent water and a number of additives. Synthetic fluids do not contain
petroleum oils but comprise
water and many other additives to help in lubricating the metals exposed
thereto.
Metalworking fluids, irrespective of which class they belong to, may contain
one or more of a
variety of additives, including, but not limited to: sulfiffized or
chlorinated compounds; corrosion inhibitors;
anti-mist agents; anti-weld agents; emulsifiers; alkanolamines; biocides;
preservatives; stabilizers;
dispersants; defoamer; colourants; dyes; odourants; and fragrances.
A concern when using metalworking fluids is the propensity to have
contaminants present in the
fluid. Said contaminants can result in growth of bacteria and fungi in said
fluid. The impact of the bacteria
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Date Regue/Date Received 2022-10-21
in a metalworking fluid is non-negligible as it leads a degradation of the
emulsion and thus a complete
breakdown of the fluid's properties. To overcome the presence and growth of
bacteria in those fluids,
biocides are routinely used, however, biocide products do present hazards
themselves. 'Tramp oil' is
another possible contaminant in MWFs. It is an oil used to lubricate machines,
such as hydraulic oil, gear
box oil, and other lubricants. Tramp oils can provide a source of nutrients
for bacteria, and thus their
presence in MWFs is undesirable. Other MWFs contaminant include metals pieces,
water and polyaromatic
hydrocarbon.
MWFs have been associated with several health concerns including but not
limited to, contact
dermatitis, asthma and lung irritation (by breathing the mist), chronic
bronchitis, and impaired lung
function. In the past, some chemicals found in certain MWF formulations have
been linked to increased
risk of certain cancers such as larynx, rectum, pancreas, skin, scrotum, and
bladder. However, because of
the lapse of time between exposure and the appearance of symptoms or
development of the disease can be
up to sat least 1 or two decades, most of the cancer cases associated with the
use of MWFs are the result of
exposure which took place in the 1970s or even before then. Nowadays, the risk
of developing cancer from
exposure to MWF is not as clear but discounting the possible risk should be
avoided.
Health risks resulting from exposure to MWF are not negligible. Aside from
cancer, the main
concern relates to skin and lungs.
It is known that all categories of MWFs can lead to the development of skin
irritation of varying
degree. Irritant or allergic contact dermatitis has been reported to occur
from exposure to soluble,
semisynthetic, and synthetic MWFs. Dermatitis can be caused by one or more of
a variety of the additives
used in MWF, including: biocides; rust control chemicals; corrosion
inhibitors; as well as contaminants
from metals (nickel, cobalt and chromium).
Other drawbacks of the use of MWFs include respiratory health dangers. Some of
the respiratory
issues related to exposure to MWFs include: work-related asthma, bronchitis,
irritation of the respiratory
tract and breathing difficulties. These can come about through exposure to
mist, aerosol, and/or vapours of
MWFs containing various chemicals and additives.
U.S. Pat. No. 4,421,680 teaches cleaning and degreasing compositions
containing potassium
hydroxide and sodium metasilicate pentahydrate in combination with n-
butoxyethanol, coconut
diethanolamide, cocamidopropyl betaine, isopropylamine salt of
dodecylbenzenesulfonic acid (DDBSA)
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Date Regue/Date Received 2022-10-21
and water.
US patent no. 6,420,323 B2 teaches a low-foam emulsifier system is presented
containing (a) an
ethoxylate/propoxylate of one or more C8-C18 fatty alcohols, where the
ethoxylate/propoxylate contains 2
to 6 ethylene oxide units and 4 to 8 propylene oxide units, with (b) a fatty
alcohol propoxy late or distillation
residue of fatty alcohol or fatty alcohol propoxylate, where the fatty alcohol
contains 12 to 24 carbon atoms
and up to three propylene oxide units. The weight ratio of (a) to (b) is from
1:0.3 to 0.3:1. The emulsifier
system produces a low amount of foam, and is useful in industrial metal
processing applications such as
cleaning, corrosion protection or cooling lubricant emulsions.
US patent no. 6,524,396 B1 teaches a process for metal cutting using a water-
mixed cutting
compound and subsequent cleansing and corrosion protective treatment wherein
an oil in water emulsion
is used as a cutting compound which contains; (i) an amount emulsifier system
consisting of: (a)
ethoxylates/propoxylates of fatty alcohols having 8 to 18 carbon atoms in the
alcohol, which contains 2 to
6 ethylene oxide units and 4 to 8 propylene oxide units; (b) fatty alcohols
and/or fatty alcohols propoxylates
having 12 to 24 carbon atoms in the alcohol and 0 to 3 propylene oxide units
and/or distillation residues of
such fatty alcohols; in a ratio by weight, a:b=1:0.2 to 0.2:1; and (ii)
corrosion inhibitory; and an aqueous
solution or suspension is used for cleansing an anti-corrosion treatment which
contains the same emulsifier
system and the corrosion inhibitors as the cutting compound. The cutting
compound and the cleansing and
corrosion protective treatment material comprise a system for treating the
metal during cutting and
cleansing.
US patent no. 5,284,591A discloses a multipurpose functional fluid is
disclosed which is comprised
of a major amount of a hydrocarbon oil and a minor amount, sufficient to
improve characteristics of the
fluid of a novel additive. The additive is comprised of a calcium salt
complex, a group II metal
dithiophosphate salt, a borated epoxide, a carboxylic solubilizer and a
sulfurized composition. The calcium
salt is preferably in the form of an overbased calcium sulfonate salt, the
antiwear agent is preferably in the
form of a zinc dithiophosphate salt, the borated epoxide is preferably the
reaction product of boric acid and
a 16 carbon 1,2 epoxide, the carboxylic solubilizer is preferably in the form
of a reaction product of an
acylating agent containing a substituted hydrocarbyl-based substituent
containing about 12 to 500 carbon
atoms; and the sulfurized composition is in the form of a co-sulfurized
mixture of 2 or more reactants
selected from the group consisting of at least one fatty acid ester of a
polyhydric alcohol, at least one olefin
and at least one fatty acid. Other components such as viscosity improvers and
antifoaming agent are
generally present in the fluid.
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Date Regue/Date Received 2022-10-21
US patent no. 4,675,125A teaches improved multi-purpose metal cleaning
compositions are
provided comprised of 5 to 40 parts by weight ethoxylated aliphatic alcohol or
ethoxylated alkylphenol, 4
to 20 parts by weight alkanolamine salt of a fatty acid, 2 to 15 parts by
weight boramide, 2 to 15 parts by
weight alcohol, glycol or ether glycol, 0.05 to 2.5 parts by weight antifoam
agent, and 5 to 98 parts by
weight water. In addition to being highly effective cleaners for the removal
of grease, oil, dirt, scale and
metal fines, the compositions of this invention also provide a non-sticky and
non-greasy corrosion-resistant
protective barrier on the surface of the metal.
US patent number 5,688,755A teaches a multi-purpose metal cleaning composition
comprising: (a)
to 40 parts by weight ethoxylated aliphatic alcohol or ethoxylated
alkylphenol; (b) 4 to 20 parts by weight
alkanolamine salt of a fatty acid; (c) 2 to 15 parts by weight boramide
obtained by the reaction of boric acid
or its analogs with a molar excess of alkanolamine selected from the group
consisting of diethanolamine,
diisopropanolamine and triethanolamine at a temperature of about 130 C. or
above; (d) 2 to 15 parts by
weight alcohol, glycol or ether glycol; (e) 0.05 to 2.5 parts by weight
antifoam agent; and (f) 5 to 98 parts
by weight water.
Other cleaning compositions used in the metal working industry comprise
chelating agents,
sulfonate compounds and benzesulfonic acids. These compounds carry a number of
health warnings,
including but not limited to, acute toxicity, eye damage if exposed thereto,
aquatic toxicity, etc.
In light of the state of the art, there still exists a need for a metal;
working fluid composition which
overcomes at least some of the drawbacks of the known composition. It would be
highly advantageous if
other aqueous compositions having moderate pH and which are effective cleaners
for metal surfaces were
available. It would be even more advantageous if the cleaners also provided a
non-greasy and non-sticky
protective barrier on the surface of the metal to prevent rust and corrosion
during storage and shipping.
These and other advantages are realized with the metal cleaning compositions
of the present invention.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, there is provided
a chelating agent-free
composition for use in metalworking cleaning, wherein said composition
comprises:
- water;
- a caustic component;
- a solvent;
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Date Regue/Date Received 2022-10-21
- an anionic surfactant;
- a nonionic surfactant;
- optionally, a corrosion inhibitor;
- a fatty alcohol polyglycol ether; and
- a hydrophobic component.
According to a preferred embodiment of the present invention, the solvent is
selected from the
group consisting of: methanol; ethanol; isopropanol, 1-propanol; and glycol
ether. Preferably, the solvent
is present in an amount ranging from 5 to 15 wt % of the total weight of the
composition.
According to a preferred embodiment of the present invention, the anionic
surfactant comprises an
alkyldiphenyloxide disulfonate. Preferably, the alkyldiphenyloxide disulfonate
is Dowfax C 10L.
Preferably, anionic surfactant is present in an amount ranging from 5 to 15 wt
% of the total weight of the
composition.
According to a preferred embodiment of the present invention, the fatty
alcohol polyglycol ether,
is Emuldac 251 PE. Preferably, the fatty alcohol polyglycol ether is present
in an amount ranging from 1
to 5 wt % of the total weight of the composition.
According to a preferred embodiment of the present invention, where the
nonionic surfactant is an
ethoxylated alcohol. Preferably, the nonionic surfactant is Novel 23E3.
Preferably, the nonionic
surfactant is present in an amount ranging from 5 to 20 wt % of the total
weight of the composition.
According to a preferred embodiment of the present invention, the hydrophobic
component is a
naphthenic mineral oil. Preferably, the hydrophobic component is pale oil 40.
Preferably, the hydrophobic
component is present in an amount ranging from 2 to 5 wt % of the total weight
of the composition.
According to a preferred embodiment of the present invention, the caustic
component is selected
from the group consisting of: potassium hydroxide or a modified caustic soda.
Preferably, the caustic
component is present in an amount ranging from 0.01 to 0.5 wt % of the total
weight of the composition.
Preferably, the corrosion inhibitor is present in an amount ranging from 0.5
to 5 wt % of the total
weight of the composition.
Date Regue/Date Received 2022-10-21
According to a preferred embodiment of the present invention, the pH of the
composition ranges
from 7 to 13. Preferably, the pH of the composition ranges from 8 to 12.
According to a preferred embodiment of the present invention, the metal
cleaning composition
comprises ingredients which are readily compatible and when combined in the
proportions indicated
provide a cleaner concentrate which can be used as such or further diluted
with water. The aqueous cleaner
compositions of this invention are highly effective cleaners for the removal
of residual oil, dirt, scale, metal
fines from metal surfaces. They further provide good rust resistance as well
as good metal corrosion-
resistance.
BRIEF DESCRIPTION OF THE FIGURES
Features and advantages of embodiments of the present application will become
apparent from the
following detailed description and the appended figures, in which:
Figure 1 is a picture of bolts covered in grime before and after cleaning with
a composition
according to a preferred embodiment of the present invention;
Figure 2 is picture of various greased metallic coupons before and after
cleaning with a
composition according to a preferred embodiment of the present invention;
Figures 3a and 3b are pictures of the surface of Test A: AL5083 metallic
coupon after being
exposed to a composition according to a preferred embodiment of the present
invention for 6 hrs at 68 F
(20 C) at 10X magnification (left) and 40X magnification (right).
Figures 4a and 4b are pictures of the surface of Test B: AL7075 metallic
coupon after being
exposed to a composition according to a preferred embodiment of the present
invention for 6 hrs at 68 F
(20 C) at 10X magnification (Figure 4a) and 40X magnification (Figure 4b).
Figures 5a and 5b are pictures of the surface of Test C: ABS metallic coupon
after being exposed
to a composition according to a preferred embodiment of the present invention
for 6 hrs at 68 F (20 C) at
10X magnification (left) and 40X magnification (right).
DETAILED DESCRIPTION OF THE INVENTION
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Date Regue/Date Received 2022-10-21
According to a preferred embodiment of the present invention, the metal
cleaning composition can
comprise a combination of surfactants which are environmentally friendly and
when formulated as part of
an emulsion can be highly effective at removing various hydrophobic
contaminants. Preferably, the
composition is an effective cleaner for metalworking equipment which can
minimize the overall dosage of
chemical cleaners required compared to conventional compositions. Moreover, in
a preferred embodiment,
the composition can be useful for various applications and thus be considered
a multi-purpose cleaning
composition.
Most cleaners are diluted with tap water and hence required a chelating agent
to ensure hard water
stability. The most common chelator is EDTA which is resistant to bacterial
biodegradation. Hence, it is
desirable to have a hard-water stable high-performance cleaner which does not
contain any chelating agent.
According to a preferred embodiment of the present invention, the metal
cleaning composition
comprises a microemulsion which is hard-water stable without any chelating
agent. Preferably, a minimum
concentration of the oil phase is present.
The composition according to a preferred embodiment of the present invention,
is novel as it is a
microemulsion. The oil phase, unlike the prior art, allows to encapsulate the
surfactants into micellar
structures which allow the composition to be stable in hard water without the
need for a chelating agent.
According to a preferred embodiment of the present invention, the metal
cleaning composition is
an alkaline metal cleaning composition. Preferably, it is a highly
concentrated, alkaline cleaner that can be
used to clean and degrease a wide variety of soils in many different
applications.
According to a preferred embodiment of the present invention, the alkaline
metal cleaning
composition is a microemulsion-based cleaning composition that encapsulates a
blend of eco-friendly
surfactants to improve penetration and emulsification of soils for efficient
removal from surfaces.
According to a preferred embodiment of the present invention, the metal
cleaning composition
provides at least one of the following advantages:
- a highly concentrated formula;
- encapsulation of surfactants improves penetration and
emulsification for efficient removal
of soils;
- improved break down of fats, oil and greases over neutral
cleaners;
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Date Regue/Date Received 2022-10-21
- capable of removing grease, viscous oils, fats, grime, cutting and
foaming oils, rust
preventative films, oxidized and sticky deposits.
According to a preferred embodiment of the present invention, the metal
cleaning composition can
be used in any one of the following applications:
- heavy duty and light duty cleaning and degreasing;
- hard surface cleaning;
- concrete surface preparation; and
- parts washers, dip tanks and pressure washing.
According to a preferred embodiment of the present invention, the metal
cleaning composition can
comprise a combination of surfactants which are environmentally friendly and
when formulated as part of
an emulsion can be highly effective at removing various hydrophobic
contaminants.
Example 1
Table 1 provides a summary of the composition of Example 1 which is a
formulation according to
a preferred embodiment of the present invention where the pH of said
formulation is alkaline. Table 2
provides a summary of various relevant physicochemical characteristics of the
composition of Example 1.
Table 1: Composition of an alkaline metal washing formulation (Example #1)
according to a
preferred embodiment of the present invention
Component wt% g
Water 57.33 57.33
KOH, 45% 0.175 0.175
Ethanol 10 10
Dowfax ClOL 10 10
Novel 23E3 15 15
CIX-2 (Corrosion
Inhibitor) 2 2
Emuldac 251PE 2 2
Pale Oil 40 3.5 3.50
Total 100 100
%active 42.7
Table 2: Physicochemical Characteristics of the composition set out in
Example 1
Sample #1 Sample #2
pH 11.5 11.52
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Date Regue/Date Received 2022-10-21
RI 1.3774 1.3775
SG 0.985 0.985
Density 0.9830 0.9833
Appearance Liquid Liquid
Smell Characteristic Chamcteristic
Color Yellow Yellow
Example 2
Table 3 provides a summary of the composition of Example 2 which is a
formulation according to
a preferred embodiment of the present invention where the pH of said
formulation is neutral. Table 4
provides a summary of various relevant physicochemical characteristics of the
composition of Example 2.
Emuldac 251 PE is a fatty alcohol polyglycol ether, based on Nafol 16 18,
propylene oxide and
ethylene oxide. It is a surfactant having a low hydrophilic-lipophilic ratio.
It is often used as antifoam agent
in papermaking. It has a cloud point of 2I-26 C, a pH (5%) level of 4.0-6.0,
and a free water content of <
0.5% wt.
Dowfax C IOL is an anionic surfactant which comprises an alkyldiphenyloxide
disulfonate. It
rinses easily from surfaces, and is readily soluble in acidic, alkaline,
bleach & other oxidizing systems. It
is also stable in hard water.
Nover23E3 ethoxylate is a biodegradable, nonionic surfactant derived from
SAFOL 23 alcohol
and ethoxylated to an average of 3 moles of ethylene oxide. It is essentially
100% active unless diluted
with water. It is a slightly hazy liquid that is readily soluble in water.
Some of its applications include, as
an emulsifier in personal care products, also it is a foaming agent. It is
referred to as an C10-16 ethoxylated
alcohol and its CAS Number is 68002-97-1. Chemical SAFOL 23 Alcohol is a blend
of C12 and C13
branched and linear alcohols. The branched isomers in SAFOL 23 Alcohol are
unique in that the branch is
located mid-chain. This leaves the primary alcohol unobstructed for further
derivatization. SAFOL 23
Alcohol is a synthetic alcohol produced from olefins obtained using the novel
Fischer-Tropsch process.
Triton hand sanitizer (THS) is a hand sanitizer comprising mainly of ethanol
(over 70 wt%) and a
few other constituents. According to a preferred embodiment of the present
invention, the source of ethanol
is from expired hand sanitizer compositions being high in ethanolic content,
for example above 60%, more
preferably above 70% even more preferably above 75% and yet even more
preferably above 80% ethanol
content. The composition used in testing is a hand sanitizer comprising: 77.3
wt% ethanol; 20.1 wt% water;
2.1 wt% glycerol; and 0.5 wt% H202.
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Date Regue/Date Received 2022-10-21
Pale oil is characterized as a straight naphthenic mineral oil. It is straw or
pale yellow in color. It
is typically used as a once-through lubricant and in the formulation of
process oils. The naphthenic oils are
available in a wide range of viscosities. Pale oil 40, Pale oil 60, Pale oil
100 and Light Pale oil are types of
naphtenic oils obtained from the same processing approach. Pale oil 40 is a
petroleum distillate,
hydrotreated heavy naphthenic, its CAS number is 64742-52-5. According to a
preferred embodiment of
the present invention, the composition comprises Pale oil 40.
According to a preferred embodiment of the present invention, the composition
comprises a
corrosion inhibitor. Preferably, the corrosion inhibitor is a composition (CD(-
2) comprising: citral at 8.8
wt%; Basocorr 2005 at 40.6 wt %; and butyl carbitol at 50.6 wt.%).
According to a preferred embodiment of the present invention, the water used
may be pure water,
ion exchange water, soft water, distilled water, and tap water. These may be
used alone or in combination
of two or more. Of these, tap water and ion-exchanged water are preferably
used from the viewpoints of
economy and storage stability. "Water" is the sum of water contained in the
form of crystal water or
aqueous solution derived from each component constituting the cleaning
composition of the present
invention and water added from the outside, and the entire composition when
water is added is 100%.
According to a preferred embodiment of the present invention, the modified
caustic soda, also
interchangeably referred to as caustic component, is selected from the group
consisting of: potassium
hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide; rubidium
hydroxide and combinations
thereof; and a modified caustic composition comprises one of the above
mentioned caustic component
(potassium hydroxide; sodium hydroxide; lithium hydroxide; cesium hydroxide;
rubidium hydroxide) in
combination with a causticity modifying additive, wherein said causticity
modifying additive can provide
an extended (more methodical and linear) buffering effect to the caustic
composition as well as greatly
lowering the freeze point and providing an increased level of dermal
protection. Examples of such modified
caustic composition can be found in Canadian patent applications CA 3,023,705;
CA 3,023,613; CA
3,023,610; and CA 3,023,604.
According to a preferred embodiment of the present invention, the modified
caustic composition
comprises:
Date Regue/Date Received 2022-10-21
- a
caustic component selected from the group consisting of: potassium hydroxide;
sodium
hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and
combinations thereof;
and
- a causticity modifying additive selected from the group consisting of:
taurine; gamma-
aminobutyric acid; aminovaleric acid; aminocaproic acid; aminocapric acid;
sulfopyruvic acid;
sulfobutanoic acid; sulfopentanoic acid; sulfohexanoic acid; phosphonium
zwitterions with either
a sulfonic acid or carboxylic acid group selected from the group consisting
of: 2-hydroxyethyl
triphenylphosphonium sulfate zwitterion; (Z- hydroxyethyptrimethylphosphonium
sulfate
zwitterion (M.W. of 200.2); (3- hydroxy-n- propyl)triphenylphosphonium sulfate
zwitterion (M.W.
of 400.4); (2-hydroxy-1- methyl-n- propyl) trimethylphosphonium sulfate
zwitterion (M.W. of
228.3); (3-hydroxy-n- propy Dtri-n- butylphosphonium sulfate zwitterion (M.W.
of 340.5); (Z -
hydroxy-1,2- diphenylethyl)- triethylphosphonium sulfate zwitterion (M.W. of
394.5); (3-hydroxy-
n- propyl)dimethylphenylphosphonium sulfate zwitterion (M.W. of 276.3); (Z-
hydroxy-n-
butyl)triisopropylphosphonium sulfate zwitterion (M.W. of 312.4); (3 -hydroxy -
1- methyl- n-
buty1)-n-butyl-di-n-propylphosphonium sulfate zwitterion (M.W. of 340.5); and
(3-hydroxy- 2-
ethyl- 4 methyl-n-penty1)-n-butyldiphenylphosphonium sulfate zwitterion (M.W.
of 450.6); -
phophoric acid ester group with an amine group; and phosphonic and phosphinic
acids and their
esters with an amine group.
According to a preferred embodiment of the present invention, the caustic
component is selected
from the group consisting of: potassium hydroxide; sodium hydroxide; and
combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic
component is present in a
concentration of up to 40 wt % of the modified caustic composition. Also
preferably, the caustic component
is present in a concentration ranging from 5 to 40 wt % of the modified
caustic composition. More
preferably, the caustic component is present in a concentration ranging from
10 to 30 wt % of the modified
caustic composition. Most preferably, the caustic component is present in a
concentration ranging from 15
to 25 wt % of the modified caustic composition. According to a preferred
embodiment of the present
invention, the caustic component is present in a concentration of 25 wt % of
the modified caustic
composition. According to a preferred embodiment of the present invention, the
causticity modifying
additive is present in a concentration ranging from 4 wt% to 25 wt % of the
composition. Preferably, the
causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the
composition. More preferably, the causticity modifying additive is present in
a concentration ranging from
wt% to 10 wt % of the composition.
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Date Regue/Date Received 2022-10-21
According to another preferred embodiment of the present invention, the
modified caustic
composition comprises:
- a caustic component selected from the group consisting of: potassium
hydroxide; sodium
hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and
combinations thereof;
and
- a causticity modifying additive selected from the group consisting of:
monoethanolamine;
diethanolamine; triethanolamine; aminomethyl propanol; propanolamine;
dimethylethanolamine;
and N- methylethanolamine. Preferably, the additive is monoethanolamine.
According to a preferred embodiment of the present invention, the caustic
component is selected
from the group consisting of: potassium hydroxide; sodium hydroxide; and
combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic
component is present in a
concentration of up to 40 wt % of the modified caustic composition. Also
preferably, the caustic component
is present in a concentration ranging from 5 to 40 wt % of the modified
caustic composition. More
preferably, the caustic component is present in a concentration ranging from
10 to 30 wt % of the modified
caustic composition. Most preferably, the caustic component is present in a
concentration ranging from 15
to 25 wt % of the modified caustic composition. According to a preferred
embodiment of the present
invention, the caustic component is present in a concentration of 25 wt % of
the modified caustic
composition. According to a preferred embodiment of the present invention, the
causticity modifying
additive is present in a concentration ranging from 4 wt% to 25 wt % of the
composition. Preferably, the
causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the
composition. More preferably, the causticity modifying additive is present in
a concentration ranging from
wt% to 10 wt % of the composition.
According to yet another preferred embodiment of the present invention, the
modified caustic
composition comprises:
- a caustic component selected from the group consisting of: potassium
hydroxide; sodium
hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and
combinations thereof;
and
- a causticity modifying additive which is glycine.
According to a preferred embodiment of the present invention, the caustic
component is selected
from the group consisting of: potassium hydroxide; sodium hydroxide; and
combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic
component is present in a
12
Date Regue/Date Received 2022-10-21
concentration of up to 40 wt % of the modified caustic composition. Also
preferably, the caustic component
is present in a concentration ranging from 5 to 40 wt % of the modified
caustic composition. More
preferably, the caustic component is present in a concentration ranging from
10 to 30 wt % of the modified
caustic composition. Most preferably, the caustic component is present in a
concentration ranging from 15
to 25 wt % of the modified caustic composition. According to a preferred
embodiment of the present
invention, the caustic component is present in a concentration of 25 wt % of
the modified caustic
composition. According to a preferred embodiment of the present invention, the
causticity modifying
additive is present in a concentration ranging from 4 wt% to 25 wt % of the
composition. Preferably, the
causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the
composition. More preferably, the causticity modifying additive is present in
a concentration ranging from
wt% to 10 wt % of the composition.
According to yet another preferred embodiment of the present invention, the
modified caustic
composition comprises:
- a caustic component selected from the group consisting of: potassium
hydroxide; sodium
hydroxide; lithium hydroxide; cesium hydroxide; rubidium hydroxide and
combinations thereof;
and
- a causticity modifying additive selected from the group consisting of:
lysine monohydrochloride;
threonine; methionine; glutamic acid; and taurine. Preferably, the causticity
modifying additive is
lysine monohydrochloride or taurine. More preferably, the causticity modifying
additive is lysine
monohydrochloride.
According to a preferred embodiment of the present invention, the caustic
component is selected
from the group consisting of: potassium hydroxide; sodium hydroxide; and
combinations thereof.
Preferably, the caustic component is sodium hydroxide. Preferably, the caustic
component is present in a
concentration of up to 40 wt % of the modified caustic composition. Also
preferably, the caustic component
is present in a concentration ranging from 5 to 40 wt % of the modified
caustic composition. More
preferably, the caustic component is present in a concentration ranging from
10 to 30 wt % of the modified
caustic composition. Most preferably, the caustic component is present in a
concentration ranging from 15
to 25 wt % of the modified caustic composition. According to a preferred
embodiment of the present
invention, the caustic component is present in a concentration of 25 wt % of
the modified caustic
composition. According to a preferred embodiment of the present invention, the
causticity modifying
additive is present in a concentration ranging from 4 wt% to 25 wt % of the
composition. Preferably, the
causticity modifying additive is present in a concentration ranging from 5 wt%
to 15 wt % of the
13
Date Regue/Date Received 2022-10-21
composition. More preferably, the causticity modifying additive is present in
a concentration ranging from
wt% to 10 wt % of the composition.
According to a preferred embodiment of the present invention, the high foaming
caustic cleaning
composition with polymer for removing and suspending particulates from ship
holds comprises a modified
caustic composition, comprising lysine, NaOH and water to ensure dermal
safety. According to a preferred
embodiment of the present invention, the modified caustic soda used in the
composition comprises 25%
NaOH, 4% Lysine and 71 % water.
Parts Cleaning
In a first test, grimy screws were placed in the composition of Example #1
(diluted to 1% in water)
for 15 minutes then dried with a paper towel (Figure 1).
Figure 2 shows several greased coupons before and after cleaning with
according to a preferred
embodiment of the present invention. Used metal coupons were placed in 1% of
the composition of
Example #1 (in tap water) for 15 minutes. Then the coupons were placed in
crude oil (Spearfish formation)
for 15 minutes. The oily coupons were then placed into the composition of
Example #1 again (15 min) to
remove the oil. The same procedure was repeated but the oily coupons blotted
before placing them into the
composition of Example #1. Before and after pictures were taken as shown
below. Used coupons were
used so the oil can stick to the rougher corrosion surface. The metallic
coupons used included: P110, 316,
J55, L80, C1018 and F12801. As can be clearly seen in the "after" images, the
oil film was removed
completely. The performance of the composition tested in cleaning several
metal parts that were heavily
contaminated with oil showed that it did, in each instance, clean them very
effectively.
Corrosion Testing
Procedure:
Corrosion tests were performed in glass jars at ambient conditions on various
metals. The summary
of the corrosion test is set out in Table 5. Before testing each coupon was
cleaned with DI water and acetone
and airdried. The coupons were weighed on a 4-digit analytical balance and
placed in ajar. Test fluid was
added until the coupon was completely submerged. After the exposure period,
the coupon was removed,
washed with water, followed by an acetone wash, air dried, and then weighed.
The corrosion rate was
determined from the weight loss, and the pitting index (Table 7) was evaluated
visually at 40X
magnification, and a photo of the coupon surface at 10X and 40X magnification
was taken.
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Date Regue/Date Received 2022-10-21
Table 5: Corrosion test conditions
Temperature Duration
Test Test Fluid Coupon Tested
(oF) ( c) (hrs)
A composition of Example 141 AL5083 68 20 6
composition of Example 141 AL7075 68 20 6
composition of Example 141 ABS 68 20 6
Results:
The corrosion test results are shown in Table 6 and in Figures 3, 4, and 5.
There is no observable
corrosion or pitting on any of the three coupons tested. This confirms that
the compositions according to a
preferred embodiment of the present invention is effective and compatible with
a wide variety of metals.
Table 7 provides a literature reference for pitting which is referred to in
the testing reported herein.
Table 6: Coupon corrosion test results of experiments carried out at 20 C
(68 F)
Corrosion Rate Pitting
Test Test Fluid Coupon Tested
(mm/year) (lb/ft 2) Index
A composition of Example 141 AL5083 0 0 0
composition of Example 141 AL7075 0 0 0
composition of Example 141 ABS 0 0 0
Table 7: Pitting Index Rating Scale
(from FinSgar, M.; Jackson, J. Corrosion Science, 2014, 86, 17-41)
Description of Pitting Pitting Index
No pits. The surface is the same as for the original untreated coupon
Intergranular corrosion on the cut edge of the coupon, giving a sintered
1
effect; no pits on major surfaces
Small, shallow pits on cut edges: no pits on major surfaces 2
Scattered, very shallow pinpoint pits, less than 25 pits on either surface ¨
i.e.
3
on front or back
More than 25 pits of Pitting Index 3 on either surface 4
Ten or fewer pits, 1/32" to 1/16" diameter, 1/64" to 1/32" deep 5
11 to 25 Pits of Pitting Index 5 6
More than 25 pits of Pitting Index 5 7
Pits larger than 1/16", but less than 1/8" in diameter, greater than 1/32"
deep,
8
100 or fewer in number
Any pitting more severe than Pitting Index 8 9
Preferably, the solvent is an alcohol, where its presence allows the various
constituents in the metal
cleaning composition to be compatible and helps in preventing separation
and/or gel formation. Preferably,
the alcohols which are useful include branched- or straight-chain alcohols
having 2 to 5 carbon atoms.
Date Regue/Date Received 2022-10-21
More preferably, ethanol and isopropanol are particularly useful aliphatic
alcohols in the composition
according to the present invention.
All of the above constituents are combined with water in the proportions
indicated herein to obtain
a metal cleaning composition according to the present invention. The metal
cleaning composition may be
obtained as a "concentrate", which can be used as such for certain
applications or further diluted with water.
While the foregoing invention has been described in some detail for purposes
of clarity and
understanding, it will be appreciated by those skilled in the relevant arts,
once they have been made familiar
with this disclosure that various changes in form and detail can be made
without departing from the true
scope of the invention in the appended claims.
16
Date Regue/Date Received 2022-10-21
