Patent Application
20070276038
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.
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:
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:
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:
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:
Or more generally:
The dioleate ester can easily be made, which has the following structure:
Or more generally, for the diester:
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, bromonitrobutanediol, 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 bromonitromethane 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 bromonitromethanediol and similar diols are equally effective.
The present invention also includes using a BNPD or BNPD analog as the terminus, such as:
Where R′ can be, but is not limited, to CH2OH, OH, CH3, or H.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
This is a continuation-in-part of co-pending application Ser. No. 11/603,356 filed Jun. 25, 2003. application Ser. No. 11/603,356 is hereby incorporated by reference. This application also is related to, and claims priority to U.S. Provisional patent application No. 60/802,910 filed May 24, 2006. Application No. 60/802,910 is hereby incorporated by reference. Co-pending parent application Ser. No. 11/603,356 is related to, and claims priority from, U.S. Provisional patent application No. 60/392,007 filed Jun. 26, 2002. Application No. 60/392,007 is also hereby incorporated by reference. This application also incorporates by reference my other patent application Ser. No. 10/350,928 filed Jan. 23, 2003 entitled Polymers with Antimicrobial, Bioresistant and Fungal Resistant Properties.
| Number | Date | Country | |
|---|---|---|---|
| 60802910 | May 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11603356 | Nov 2006 | US |
| Child | 11800569 | US |
