U.S. patent application number 12/287726 was filed with the patent office on 2009-05-28 for esters with antimicrobial, bioresistant and fungal resistant properties.
Invention is credited to Thomas Daly.
Application Number | 20090137838 12/287726 |
Document ID | / |
Family ID | 46332027 |
Filed Date | 2009-05-28 |
United States Patent
Application |
20090137838 |
Kind Code |
A1 |
Daly; Thomas |
May 28, 2009 |
Esters with antimicrobial, bioresistant and fungal resistant
properties
Abstract
A bromine/nitro moiety linked into the backbone of an ester or
other compound over a wide range of occurrence rates provides
antimicrobial, bio-resistant and fungal resistant properties for
metal working fluids (MWF)s and other coatings. The moiety can be
have the bromo and nitro groups linked to the same or different
carbon atoms. The present invention also relates to urethanes,
urea, amides, imides, carbonates, ethers, siloxanes, and many other
types of linkages essential to MWF bases.
Inventors: |
Daly; Thomas; (Chicago,
IL) |
Correspondence
Address: |
CLIFFORD H. KRAFT
320 ROBIN HILL DR.
NAPERVILLE
IL
60540
US
|
Family ID: |
46332027 |
Appl. No.: |
12/287726 |
Filed: |
October 10, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11800569 |
May 7, 2007 |
7439376 |
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12287726 |
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11603356 |
Nov 21, 2006 |
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11800569 |
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60802910 |
May 24, 2006 |
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Current U.S.
Class: |
560/118 |
Current CPC
Class: |
C07C 229/12 20130101;
C23F 11/145 20130101; C11D 1/667 20130101; C10M 133/32 20130101;
C08G 77/392 20130101; C10M 2215/003 20130101; C07C 57/52 20130101;
C10N 2030/16 20130101; C07C 205/50 20130101; C11D 7/32 20130101;
C10M 105/56 20130101; C10N 2040/22 20130101; A01N 37/12 20130101;
C23F 11/147 20130101; C09K 15/20 20130101; B01D 19/0413 20130101;
C07C 205/51 20130101; C08G 77/388 20130101; C07F 7/0838 20130101;
C10M 2215/202 20130101; C10N 2030/18 20130101 |
Class at
Publication: |
560/118 |
International
Class: |
C07C 229/46 20060101
C07C229/46 |
Claims
1) A metal working lubricant of the following Structure:
##STR00009## Where R and R' are the same or different, saturated or
unsaturated, straight chain or branched alkyl from 1 to 22
carbons.
2) A metal working lubricant of the following structure:
##STR00010## Where R and R' are the same or different, saturated or
unsaturated, straight chain or branched alkyl from 1 to 22
carbons.
3) A metal working lubricant of the following Structure:
##STR00011## Where R and R' are the same or different, saturated or
unsaturated, straight chain or branched alkyl from 1 to 22 carbons.
Description
[0001] This is a continuation of co-pending application Ser. No.
11/800,569 filed May 7, 2007, now U.S. Pat. No. 7,439,376 which was
a continuation-in-part of application Ser. No. 10/603,356 filed
Jun. 25, 2003, now abandoned, which was related and claimed
priority from provisional patent application No. 60/392,007 filed
Jun. 26, 2002; that application was also related to and claimed
priority from provisional patent application No. 60/802,910 filed
May 24, 2006. Application Ser. Nos. 11/800,569, 10/603,356,
60/392,007 and 60/802,910 are hereby incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of esters and
more particularly to esters with bioresistant, fungal resistant and
antimicrobial/antifungal properties.
[0004] 2. Description of the Problem Solved by the Invention
[0005] Due to environmental regulation, the use of tin, mercury,
lead, and other heavy metals to control the growth of microbes in
organic systems is now prohibited. In particular metal working
fluids (MWF) and metal working fluid bases suffer a failure mode
when attacked by microbes. The problem is especially acute in water
extendable and emulsion MWF systems. The attack of the microbes on
the MWF base causes the pH of the system to drop, which
destabilizes the emulsion and also increases the corrosion of metal
parts that are exposed to the attacked fluid. Aside from the
obvious problems that microbes cause in MWFs, operator health
issues also arise due to continuous exposure to high levels of
bacteria.
[0006] Current systems in place include the addition of biocides to
the fluid to prevent the bacteria from breaking down the MWF. One
common biocide in use is the family of isothiazolinones. This
product family is generally hazardous to handle and causes
sensitization in many people when exposed repeatedly. The
sensitization often takes the form of itching all over the body, or
hives when any part is in contact with the isothiazolinone.
Additionally, the isothiazolinone family is relatively unstable at
the alkaline pH that most MWFs are maintained at. This then
requires the operator to add more material on a regular basis.
Also, the microbes develop a tolerance to isothiazolinones. This
again requires the operator to increase the amount of the
isothiazolinone in the system.
[0007] A second biocide technology is the use of formaldehyde
condensates. These materials are generally hazardous, but do not
lead to sensitization of the operators in contact with the MWF. The
formaldehyde condensates do contribute to free formaldehyde in the
workplace, but the results are not consistent as to how much
formaldehyde they contribute to the workplace atmosphere. Most
formaldehyde condensates are volatile and evaporate. This requires
their replenishment on a regular basis even when they are not
consumed.
[0008] What is needed is a system that uses an ester as the MWF
base that is not susceptible to microbial attack. The material
fails to act as a food source for the microbes that are able to
digest the current MWF bases.
SUMMARY OF THE INVENTION
[0009] The present invention relates to an ester that contains an
antimicrobial moiety that is linked into the backbone of the
molecule. This moiety is, in general, a bromine atom and a nitro
(NO2) group linked to one or more of the carbon atoms forming the
backbone of the molecule that is the MWF base. While the present
invention is directed primarily to esters, the moiety taught should
also be effective when linked onto a carbon atom in the backbone of
any suitable MWF base molecule. The moiety can appear in the
backbone of the MWF base in various levels of occurrence. A
preferred occurrence of around 1000 parts per million on a weight
basis is effective; however the frequency of occurrence can be as
low as 5 parts per million to as high as 99-100%. MWF base types
within the scope of the invention include, but are not limited to
urethane, urea, amide, ester, carbonate, ether, and siloxane
linkages.
[0010] It is well known in the art to combine a carboxylic acid and
an alcohol in the presence of a suitable catalyst to form an ester.
The present invention adds a bromo-nitro substituted alcohol, diol
or polyol to a standard alcohol to be used in the ester synthesis.
The proportion of substituted compound used is chosen to yield the
desired concentration of the moiety in the final MWF base. A
preferred diol for the application is bromonitropropanediol or
2-bromo-2-nitro-propane-1-3-diol or simply BNPD. This particular
diol is a solid material with varying degrees of solubility in
other alcohols and has proven antimicrobial properties.
[0011] In addition, BNPD has been shown to have no tetragenecy
(cancer causing effects) and is approved by the CFTA at levels of
up to 0.1% for use in cosmetics. BNPD has also been used in baby
wipes for its antimicrobial properties.
[0012] The fact that the active antimicrobial moiety is covalently
linked directly into the backbone of the ester reduces its
breakdown at the alkaline pHs required of MWFs. In addition, the
moiety is not photo-active or decomposed by sunlight or exposure to
mineral salts such as calcium chloride, magnesium hydroxide and
sodium chloride as are found in hard and softened water.
[0013] Because BNPD is a substituted diol, it is a natural reactant
to form part of an ester linkage with a carboxylic acid. Also,
being a diol, it mixes directly with a wide range of alcohols or
polyols and other performance enhancing additives with no
difficulty or adverse reactions. In fact, it can be mixed in any
desired proportion (to the extent that it is soluble) with any
standard alcohol used in synthesizing esters, ethers, or urethane
type linkages.
[0014] While bromonitropropanediol (BNPD) is the preferred
antimicrobial agent because of its proven activity and its benign
effects on the environment and on humans, other alcohols, diols or
polyols with bromine and nitro groups linked at the same or
different carbon atoms can also be incorporated into the backbone
of MWF bases. Any other antimicrobial agents that can be linked
onto an alcohol reacted linkage are within the scope of the present
invention.
DESCRIPTION OF THE FIGURES
[0015] FIG. 1 shows the formation of an ester linkage with
BNPD.
[0016] FIG. 2 shows treatment of BNPD with ammonium hydroxide to
form an amide.
[0017] FIG. 3 shows the formation of both urethane and urea
linkages.
[0018] FIG. 4 shows the synthesis of an acid functional, pendant
fatty chain.
[0019] Several drawings and illustrations have been presented to
aid in understanding the present invention. The scope of the
present invention is not limited to what is shown in the
figures.
DETAILED DESCRIPTION OF THE INVENTION
[0020] It is well known in the art to combine alcohols with
carboxylic acids to form ester linkages. One example is isopropyl
oleate, the ester of isopropyl alcohol and oleic acid. Polyols are
also commonly used, such as in the production of Lexolube 21-214 by
Innolex. A typical ester will have the following formula:
##STR00001##
where R typically comes from the original carboxylic acid and R'
typically comes from the original alcohol. It is well known in the
art that R and R' can be the same or different. The typical example
noted above as isopropyl oleate has the following structure:
##STR00002##
[0021] The compound bromonitropropanediol or
2-bromo-2-nitro-propane-1,3-diol (BNPD) has known antimicrobial
properties. Tests on this compound have shown that it is effective
against various strains of both gram positive and gram negative
bacteria in concentrations of 1-50 ppm with the average minimum
inhibitory concentration being around 25 ppm. In addition, work has
indicated that BNPD is also antifungal. BNPD has the following
structure:
##STR00003##
[0022] Because BNPD is a polyol, it can be combined with other
alcohols, diols, or polyols in the manufacture of the esters used
as MWF bases. In particular, BNPD alone or mixed with other
alcohols, can be combined with carboxylic acids to form esters that
are suitable for use as MWF bases. This causes the active moiety to
become covalently linked into the ester. In the case of the oleate
ester, the product is:
##STR00004##
Or more generally:
##STR00005##
The dioleate ester can easily be made, which has the following
structure:
##STR00006##
Or more generally, for the diester:
##STR00007##
[0023] While BNPD is a preferred polyol starting point to link the
active moiety into an ester MWF base, it is within the scope of the
present invention to use many other materials that contain a
bromine atom and nitro group linked near one another. The preferred
class of compounds contains the bromine and nitro linked to the
same carbon atom; however, it is felt that a moiety where the
bromine and nitro are not linked to the same carbon, but near each
other will still be effective. Many other similar compounds can
also be used. In particular, bromonitromethanediol,
bromonitroethanediol, bromo-nitrobutanediol, etc. can also be
substituted into molecule backbones with similar results. It should
be understood that these are just examples of the many compounds
within the scope of the present invention. The prior art has shown
that bromonitro-methane is effective for the treatment of nematodes
in the soil (See U.S. Pat. No. 5,013,762 which is hereby
incorporated by reference) and as a general biocide (See U.S. Pat.
No. 5,866,511 which is hereby incorporated by reference). It is
felt that bromo-nitromethanediol and similar diols are equally
effective.
[0024] The present invention also includes using a BNPD or BNPD
analog as the terminus, such as:
##STR00008##
[0025] Where R' can be, but is not limited, to CH2OH, OH, CH3, or
H.
[0026] The present invention reacts BNPD or similar substituted
alcohols, diols or polyols, with or without the aid of a solvent or
co-solvent, with a carboxylic acid to form the ester MWF base.
[0027] The present invention results in a covalently linked
bromine/nitro moiety in the backbone of an ester at some frequency
of occurrence that provides antibacterial or anti-fungal effects.
The present invention relates to ester, urethane, urea, amides,
imides, carbonates, ethers, siloxanes, and many other types of
linkages essential to MWF bases.
[0028] FIG. 1 shows the formation of an ester linkage with BNPD.
FIG. 2 shows treatment of BNPD with ammonium hydroxide to form a
bromonitro amine or diamine which can then be combined with an
aldehyde or carboxylic acid to form an amide. FIG. 3 shows the
formation of both urethane and urea linkages. FIG. 4 shows the
synthesis of an acid functional, pendant fatty chain.
[0029] The present invention is particularly well suited to use in
metal working fluids, not just as an additive, but as a base oil
for use in oil soluble cutting oils. The diester structure of the
esters of the present invention make them natural components to use
as a replacement, in full or in part, of the base oil, particularly
in cases where the base oil is a neopentyl glycol ester or diester.
The similarity of structure between the esters of the present
invention and the neopentyl glycol esters allow the direct
substitution of the neopentyl glycol ester while maintaining the
desired properties, such as lubricity, with a minimal need for
reformulation, while still obtaining the antimicrobial and
biostatic properties.
[0030] The dialkyl and diallyl forms are not generally water
soluble, and may or may not be useful in aqueous systems such as
cooling tower water, paper process water, and other industrial
process waters; however, the compounds represented by the present
invention can be readily emulsified into synthetic, semi-synthetic
metal working fluids and water dilutable metal working fluids in
general. Replacing portions of the base oil component, such as oil
soluble esters or hydrotreated naphthenics (commonly referred to as
100, 200, etc. second oils in reference to their viscosities, or
commonly by the tradename HYDROCAL), is one possible way to
incorporate the present invention to obtain the benefits of the
lubrication and antimicrobial properties.
[0031] Embodiments of the present invention wherein R and/or R'
include a polyether group, such as, but not limited to,
polyethylene oxide, polypropylene oxide and polybutylene oxide, the
present invention can act as a surfactant, foaming agent, anti-foam
and emulsion breaker depending on the degree of ethoxylation,
propoxylation, and/or butoxylation. This embodiment enables the
present invention to be used as an emulsifier in water dilutable
metal working fluids, and more generally, as a surfactant in any
application where a surfactant and an antimicrobial would be
beneficial.
[0032] The present invention can also function as a corrosion
inhibitor. While controlling microbial growth does play an
important part in controlling pH, and therefore corrosion, the high
electron density of the center of the molecule attracts it to the
metal surface and the Alkyl branches that extend out act as a
barrier to water and corrosive salts. This typical film forming
mode of action of corrosion inhibition can be exploited not only
for the time the part being worked is in contact with the fluid,
but the draw-out that occurs keeps the present invention on the
part surface well after processing. This is a major benefit of the
present invention since corrosion is often more of a problem while
the part sits between processing steps or prior to packaging and/or
shipping.
[0033] Further application for the present invention is in
so-called spray shower cleaners, such as the FRESH SHOWER
(registered trademark) brand by Clorox. Addition of the compounds
of the present invention maintains the water sheeting action, while
adding a persistent antimicrobial that does not simply wash away.
Further, the use of the present invention in this application is
safe for many bathroom surfaces such as marble that are damaged by
other antimicrobials and even by EDTA (ethylenediamine tetraacetic
acid).
[0034] Embodiments of the present invention are also useful as a
skin surface antimicrobial. They are non-toxic and have very mild
handling characteristics. By applying them in a formulation similar
to other skin creams and washes, the present invention is expected
to be effective against a wide range of skin surface pathogens.
Pathogens, such as the fungi that cause yeast infections (candida)
and athlete's foot (trichophyton), as well as more generally those
that cause ringworm and many other pathogens can be controlled or
eliminated by the present invention. Bacterial skin conditions such
as boils caused by various strains of staphylococcus bacteria and
many other skin bacterial conditions can also be controlled or
remedied by the present invention. When properly applied, the
present invention can act as a remedy for thrush.
[0035] The esters of the present invention make excellent starting
materials for sulfonate surfactants. One route, but not the only
route, to formation is by reacting the product above with sodium
metabisulfite or sodium sulfite. A very useful anionic surfactant
can be produced that has strong microbial resistance.
[0036] The esters of the present invention can also serve as
excellent starting materials for functional replacements of
sulfurized fats having strong microbial resistance. One route, but
not the only route, is the cross linking or "vulcanizing" of these
compounds with sulfur, or other materials, such as transition metal
based complexes, including, but not limited to, cobalt and zinc
complexes. These produce excellent lubricity aids for metal working
fluids and other applications that require higher levels of
lubricity and that can benefit from microbial resistance. A
specific example of transition metal cross-linkers is cobalt
octoate. Conversely, the vulcanizing or cross linking the
carboxcylic acids prior to esterification will also produce good
results.
[0037] The examples and illustrations presented herein are for the
purpose of understanding the concepts of the present invention. It
will be clear to one with ordinary skill in the art that many other
examples and structures are within the scope of the present
invention. This applies particularly to classes of linkages where
an example of one particular structure has been given; it will be
appreciated by one skilled in the art that in such a case, the
entire class of compound is within the scope of the present
invention.
EXAMPLE 1
Production of a Metal Working Fluid Base
[0038] A vessel equipped with vacuum and heat was charged with 109
g (0.531 moles) of undecanoyl chloride and 48 g of BNPD (0.241
moles). The vessel was heated to 60 C. The temperature was held for
3 hours. The BNPD diundecanoate recovered was a translucent light
yellow liquid.
* * * * *