Environmentally Benign Antifouling Coating

Abstract

The present invention is directed to environmentally benign coatings that can prevent fouling of submerged structures and surfaces in the marine environment. The coating is essentially a grease composition composed of an organic acids salt, mineral oil, a solvent and alkaline silicate. The sulfonate thickener is an oil soluble dispersing agent selected from a plurality of organic acids in a form of alkali metal salt or alkaline earth metal salt thereof, such as calcium sulfonate. Coating compositions of the invention can be used to coat surfaces, such that when such surfaces are exposed to or kept submerged in seawater they will prevent fouling of such surfaces when exposed to the marine environment for extended time.

Claims

1. An antifouling coating composition comprising: (a) in the range of about 10% to about 70% by weight of the final composition of at least one neutral or overbased salt of an organic acid selected from the group consisting of sulfonates, phosphonates, carboxylates and phenates, and (b) in the range of about 10% to about 70% by weight of the final composition of at least one type of mineral oil, and (c) in the range of about 1% to about 30% by weight of the final composition of at least one type of a water miscible organic solvent, and (d) in the range of about 2% to about 40% by weight of the final composition of at least one type of alkaline silicate solution.

2. The composition of claim 1, comprising in the range of about 10% to about 60% by weight of the at least one neutral or overbased salt of an organic acid, preferably about 10% to about 50%.

3. The composition of claim 1, comprising in the range of about 10% to about 60%, preferably about 10% to about 50%, more preferably about 20% to about 50%, of the mineral oil.

4. The composition of claim 1, comprising in the range of about 2% to about 30%, preferably about 3% to about 25%, of the water miscible organic solvent.

5. The composition of claim 1, comprising in the range of about 5% to about 35%, preferably about 10% to about 35%, of the alkaline silicate solution.

6. The composition of claim 1, wherein the neutral or overbased salt of an organic acid is an oil-soluble sulfonic acid salt.

7. The composition of claim 1, wherein the neutral or overbased salt of an organic acid is an oil-soluble sulfonic acid salt of one or more petroleum sulfonic acid or one or more synthetic sulfonic acids, including alkyl sulfonic acids, alkaryl sulfonic acids and aromatic sulfonic acids.

8. (canceled)

9. The composition of claim 1, wherein the neutral or overbased salt is a sodium salt, a barium salt or a calcium salt.

10. The composition of claim 1, wherein the water soluble organic solvent of (c) is an alcohol, preferably an alkyl diol or an alkyl triol of 2 to 6 carbon atoms.

11. The composition of claim 1, wherein the alkaline silicate solution of (d) is a solution of metal salt of silicic acid.

12. The composition of claim 11 wherein the alkaline silicate solution is a solution of a sodium or potassium salt of silicic acid.

13. The composition of claim 1, wherein the alkaline silicate solution comprises from about 0.5 to about 8 Mol/L of silicic acid, preferably from about 1 to about 6 Mol/L, from about 1.5 to about 4 Mol/L, or from about 1.7 to about 2.5 Mol/L, and from about 0.5 to about 8 Mol/L of sodium hydroxide, preferably from about 1 to about 6 Mol/L from about 1.7 to about 4 Mol/L or from about 2 to about 3 Mol/L, or about 0.5 to about 8 Mol/L of potassium hydroxide, preferably from about 1 to about 6 Mol/L from about 1.7 to about 4 Mol/L or from about 2 to about 3 Mol/L.

14. A method for making an antifouling coating composition comprising mixing together (a) in the range of about 2% to about 40% by weight of at least one type of alkaline silicate solution; and (b) in the range of about 3% to about 30% by weight of at least one type of a water miscible organic solvent, and (c) in the range of about 10% to about 70% by weight of at least one neutral or overbased salt of an organic acid selected from the group consisting of sulfonates, phosphonates, carboxylates and phenates, and (d) in the range of about 10% to about 70% by weight of at least one type of mineral oil wherein percentages are with respect to the weight of the final composition and continue to mix the resulting mixture to obtain a final composition that is homogeneous and of a desired consistency for spreading onto surfaces.

15. The method of claim 14, wherein the steps (a)-(d) are performed sequentially.

16-17. (canceled)

18. The method of claim 17, wherein the alkaline silicate solution is obtained by blending in total from about 10 to about 60 weight percent of sodium silicate and, from about 2 to about 40 weight percent sodium hydroxide.

19. The method of claim 14, wherein the organic acid salt is first combined with the mineral oil to obtain a paste, followed by addition of the organic solvent and the alkaline silicate solution.

20. The method of claim 14, wherein the organic solvent and the alkaline silicate solution are combined first, followed by addition of the combined organic acid salt and the mineral oil to obtain a paste.

21. The method of claim 14, wherein the method comprises the steps of: a. heating water to about 90° C. and with mixing add slowly both sodium silicate and sodium hydroxide in about equal molar proportions, blending in total together from about 10 to about 60% by weight, preferably from about 20 to about 50% by weight, more preferably from about 10 to about 30% by weight of sodium silicate and, from about 2 to about 20% by weight, preferably from about 4 to about 15% by weight, more preferably from about 5 to about 12% by weight of sodium hydroxide until a clear solution is formed; b. adding about 10 to about 70% by weight, preferably about 10 to about 45% by weight of sulfonate to about 10 to about 50% by weight of mineral oil, blending the two to make soft paste, followed by adding 3 to about 25% by weight of water soluble organic solvent and mixing; c. adding about 2 to about 35% by weight, preferably about 2 to about 27% by weight, of the alkaline silicate solution to the paste obtained in step (b) until fully mixed and soft of the desired consistency to be used for spreading onto surfaces.

22. (canceled)

23. A method of coating hard, solid substrates made of metal, stone, plastics or fiber-reinforced composites, wherein said composition of claim 1 is applied by any of coating method, such as brushing, dipping, rolling or spraying.

24. A method of coating flexible solid substrates, such as ropes and nets, made of plastics or fiber-reinforced composites, wherein said composition of claim 1 is applied by any coating method such as brushing, dipping, rolling or spraying.

25. (canceled)

Description

BRIEF DESCRIPTION OF THE FIGURES

[0034] FIG. 1A shows the results from testing of the leaching of alkalinity from a 40 cm of net line coated with the antifouling composition of the invention during 30 day incubation in different water at 15° C. The composition used here was according to formulation 110 in Table 1. The leaching was monitored by measuring pH. The leaching of the alkaline silicate from the antifouling composition in pure water was about 25%, from 10% seawater it was about 3%, from 50% seawater it was about 0.5% and from 100% seawater it was about 0.1%. No precipitate could be detected in any of the test solutions, as monitored by light absorbance.

[0035] FIG. 1B shows the results from testing of the leaching of alkalinity from a 40 cm of net line coated with the antifouling composition of the invention made with different sulfonate salts by up to 40 days incubation in different water at 15° C. The leaching was monitored by measuring pH. The compositions were made according to formulations in Table 1 indicated in brackets, Na Sulfonate (formulation 109), Ba Sulfonate (formulation 103) Ca400 overbased (formulation 112) and Ca premix sold as rust protection (formulation 110). In this context and as disclosed herein, the term “S” refers to a sulfonate salt. The leaching of the alkaline silicate from the antifouling composition in seawater was as shown. The released alkali is partly neutralized with time by polymerization of silicate and neutralization from CO.sub.2 and other components in the seawater.

[0036] FIG. 2 shows the results of toxicity testing of the leachate from a composition of the invention according to formulation 110. The leachate was produced by incubating a surface coated with the composition in seawater for 14 days according to the method described by Ytreberg et al. (2010)

[0037] FIG. 3 shows the results of an antifouling experiment done with coatings of the composition on plates kept for 50 days in the sea at natural in situ conditions close to a commercial salmon farming cage in N-Iceland. The plates were of commercial fiberglass used as building materials for boats. The two plates on the left in the upper part of the figure were treated (coated) with formulation 106 and 108, respectively. The plate furthest to the right was untreated. The lower part of the figure shows the back side of the same plates, that were also all untreated. Substantial fouling had already started on the untreated plates, whereas no fouling growth had at this time started on the treated side of the plates.

[0038] FIG. 4. Shows frames of stainless steel with 1 m.sup.2 of aquaculture cage nets treated with the composition of the invention made according to formulation 108 and kept is the sea at the same place and time as the fiberglass plates in FIG. 3. The net on the left in the figure was treated but the net on the right was untreated. Only very little fouling growth (mainly algae at this stage) was seen on the treated net whereas already a substantial settlement of algae and other fouling organisms had occurred on the untreated net.

[0039] FIG. 5. Shows the stability of the composition of the invention on plastic-type ropes when put into seawater versus in fresh water. In FIG. 5A the formulation was 102 and 104 in FIG. 5B. The coating remains intact and releases little of the alkalinity in seawater whereas it is unstable, opens up and releases much or all of the alkalinity after some time in fresh water.

DETAILED DESCRIPTION OF THE INVENTION

[0040] The invention is based on the use of known chemical and physical principles to combine chemical components in a new way, which when combined according to the present invention provide an effective antifouling coating that can be used on surfaces in the marine environment. The components of the invention are generally considered food grade and non-toxic to the environment.

[0041] The composition and method of the invention is therefore useful, environmentally friendly and commercially viable. The invention is therefore expected to be useful and consequently to have large potential for industrial application and commercial use.

[0042] The novel composition of the present invention has as its primary component and binder, a high molecular weight organic acids salt that forms a soft and open coating of surfaces that are essentially insoluble in water so the soft coating is stable and partly water-repelling but also contains micellar structures. When mixed in the proper proportions with a water soluble solvent it can incorporate a certain amount of water containing a soluble alkaline silicate at high pH and when properly mixed it forms a homogenous and stable composition that can be further diluted with mineral oils into the proper consistency as to be applied for coating of various surfaces to be immersed in sea water. Upon drying for one or few days some of the mineral oil will have evaporated making the coating dry upon touching but still soft.

[0043] In general the composition can comprise in the range of about 10% to about 70% by weight of at least one neutral or overbased salt of an organic acid selected from the group consisting of sulfonates, phosphonates, carboxylates and phenates, preferably in the range of about 10% to about 60% by weight, more preferably about 10% to about 50% by weight.

[0044] The composition further can comprise in the range of about 10% to about 70% by weight of at least one type of mineral oil, preferably in the range of about 10% to about 60% by weight, more in the range of about 10% to about 50% by weight, more preferably in the range of about 20% to about 50% by weight.

[0045] The composition further can comprise in the range of about 1% to about 30% by weight of at least one type of a water miscible organic solvent, preferably an alkyl alcohol, preferably in the range of about 2% to about 30% by weight, more preferably in the range of about 3% to about 25% by weight.

[0046] The composition further can comprise in the range of about 2% to about 40% by weight of at least one type of alkaline silicate solution, i.e. a solution containing at least one type of alkaline silicate, preferably in the range of about 5% to about 35% by weight or in the range of about 10% to about 35% by weight.

[0047] Without intending to be bound by theory, it is believed that upon immersion into seawater or brackish water, being at neutral or slightly alkaline pH and containing magnesium and calcium ions, the alkaline silicate solution is incorporated in micelles inside the organic acids salt coating, and will turn into gel, but that remains highly alkaline in nature and which together with the oily nature of the organic acid salt, will provide the antifouling activity against marine organisms attempting to settle on the surfaces that have been treated with the coatings of the present invention.

[0048] Due to the gel formation of the alkaline silicate of the invention when in seawater the alkalinity remains inside the composition and thereby having the observed antifouling effect as shown by the invention. Since gel formation is primarily facilitated in seawater from the high inherent concentrations of divalent cations such as Ca.sup.+2 and Mg.sup.+2 if forms quickly and is stable inside the composition. Gel formation of alkaline silicate is also facilitated by lowering the pH below about 10.5 so therefore when compositions of the invention containing about or below 10% of alkaline silicate solution is put in water or seawater, the measured pH can be lower than expected from the internal content of the alkaline silicate. However, when compositions of the invention contain more than 10%, and especially between 15-25% of the alkaline silicate solution and when such compositions are put in water the amount of released alkali high enough to prevent gel formation and high pH is measured. Composition containing 15-25% alkaline silicate solution is however stable in seawater and normally only less than 10% of the alkali is released in the beginning after coming into seawater but remains stable after that.

[0049] It has thus been found that the composition retains the alkaline silicate solution in seawater, which in part is believed to underly its antifouling properties. Thus, marine organism that otherwise would attach to an untreated surface or a surface treated by alternative coatings will not be viable on the treated surface, due to its biologically hostile environment.

[0050] Despite its biofouling properties, the composition is environmentally friendly, since it only contains non-toxic components, and in particular does not contain toxic trace elements such as heavy metals.

[0051] The composition can be prepared by mixing the components, i.e. a neutral or overbased organic acid salt, a mineral oil, one or more organic solvents and alkaline silicate solution. Other additives, such as biocides or other natural and/or synthetic compounds having repelling effects against fouling organisms can be added. In general, there is no particular restriction on the method of mixing these components. For example, liquid substances can be most easily mixed by using a rotary stirrer, or other suitable mixing devices and blenders. The composition can in general be prepared as a “one-pot” mixture, blending all components together. The composition can also be prepared by sequential addition of components while mixing or stirring the solution.

[0052] The organic solvent portion of the composition is believed to aid in the formation and/or stability of micelles, which is believed to represent a key feature of the antifouling properties of the composition. The organic solvent should have sufficient water and organic solvent miscibility to allow homogenous mixing of the alkaline silicate solution to the organic acid salt of and the mineral oil to form a stable and soft homogenous mixture.

[0053] The present invention also provides a method for preventing fouling of a structure which may be or is contacted with sea water by using the antifouling composition of this invention.

[0054] Structures that may come into contact with sea water includes structures in bays and ports and at sea, structures for recreational or commercial use, structures for fishery, fishing nets, aquaculture cage nets and structures located on coastal areas. Constructs include ships, boats, barge or other floating vessels, or harbor constructs, or other land or sea constructs that come into contact with seawater, such as platforms, rigs or the like.

[0055] Contact with sea water may be complete or partial insertion in seawater of a construct. The contact may also be contact via seawater that is propelled by wind or waves onto the surface, i.e. onto surfaces that normally would not be immersed in seawater but may be exposed through air-borne transmission of the seawater.

[0056] Examples of substrates which constitute the contacting portions of the above structures are substrates made of synthetic organic materials, such as plastics of various kinds (e.g. in fishing nets), but also structures made of inorganic materials such as metals and concrete.

[0057] The coating treatment of the aforesaid structures can be carried out by using any desired known means capable of coating the composition of this invention on the structures. For example, spray coating, roller coating, brush coating, or soaking and the like can be used. Since the antifouling coating composition of this invention is stable at room temperature in closed containers it can be stored for a long period of time after it is prepared and applied as convenient, just like any other paint or coating. It will therefore not fully self-cure to form the internal alkaline silicate gel until after coming in contact with seawater or similar aqueous fluids. After the coating treatment, the coated surface may be allowed to dry by itself.

[0058] The thickness of the coated layer is properly selected for the desired application, and is, for example, about 20 μm to about 1 mm.

[0059] One method of preparing the antifouling composition of the invention is by first mixing into hot water of a metal silicate, such as sodium silicate and about equal molar proportions of a base, such as sodium hydroxide, then taking a portion of the so prepared alkaline silicate solution and adding it at ambient temperatures, to a mixture already containing the organic acid salt and the mineral oil and the water soluble organic solvent in the preferred proportions.

[0060] In an embodiment, the method comprises steps of:

a. heating water to about 90° C. and with mixing add slowly both sodium silicate and sodium hydroxide in about equal proportions, blending in total from about 10 to about 60 weight percent of sodium silicate and, based on the weight of the final composition, and from about 2 to about 40 weight percent sodium hydroxide until all is soluble in a clear solution, that is also called water glass;
b. adding about 10 to about 70 weight percent of sulfonate to about 10 to about 70 weight percent of mineral oil, blending the two to make soft paste, followed by adding 3 to about 25 weight percent of water soluble organic solvent and mixing at ambient temperature;
c. adding about 2 to about 25 weight percent of the alkaline silicate solution to the paste at ambient temperatures until fully mixed and soft of the desired consistency to be used for spreading onto surfaces.

[0061] In certain embodiments of the invention the respective components of the antifouling composition can be obtained from various commercial sources, such as for example many organic acid salts used in the invention can be obtained as different metal salts or already as such mixed with suitable mineral oils in various proportions. In other words, the organic acid salt may be used as is from a commercial source that includes one or more mineral oil.

[0062] In other embodiments of the invention such commercially available components can be further modified be adding more or other types of mineral oil or the final consistency of the composition can be adjusted by adding oil or solvent after all the main components have been mixed.

[0063] In certain embodiments of the invention the alkaline silicate solution components of the antifouling composition can be obtained ready made from various commercial sources.

[0064] A further embodiment of the invention is that the alkaline solution of the invention can be prepared from other available sources such as from various silicate minerals and also that silica is available in numerous mineral forms, so-called silicate minerals, such as quartz, diatom earth and more (https://en.wikipedia.org/wiki/Silicate_minerals). It should be further understood that to those skilled in the art, that alkaline silicate solutions can be made in many different ways and with different ratios of silica, represented as SiO.sub.2 and the metal base represented with general formula as MO or MOH, most commonly as Na.sub.2O or NaOH. Furthermore it should be understood that for the purpose of the invention that silica or silicic acid can occur naturally or even in solution in different degrees of polymerization and that the alkaline silicate solution of the current invention or its components can be obtained commercially from many sources.

[0065] In one aspect of the invention, the antifouling composition can be coated on surfaces by painting, spaying or soaking of the respective surfaces to be treated. The so treated surfaces are preferably allowed to dry for one day or few days before being put into the sea at the place of use.

[0066] Unless defined otherwise, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, exemplary methods and materials are now described.

[0067] It will be appreciated that variations to the foregoing embodiments of the invention can be made while still falling within the scope of the invention. Features disclosed in the specification, unless stated otherwise, can be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless stated otherwise, each feature disclosed represents one example of a generic series of equivalent or similar features.

[0068] Use of exemplary language, such as “for instance”, “such as”, “for example” and the like, is merely intended to better illustrate the invention and does not indicate a limitation on the scope of the invention unless so claimed. Any steps described in the specification may be performed in any order or simultaneously, unless the context clearly indicates otherwise.

[0069] All of the features and/or steps disclosed in the specification can be combined in any combination and order, unless explicitly stated otherwise, except for combinations where at least some of the features and/or steps are mutually exclusive. In particular, preferred features of the invention are applicable to all aspects of the invention and may be used in any combination.

[0070] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages.

Example 1

[0071] This example demonstrates several different compositions of the chemical components in the invention. Table 1 shows several possible weight ratios of the different components that can be mixed in order to obtain a functional and useful antifouling composition. The type of sulfonate used is as follows; BaS, neutral Barium sulfonate of average molecular weight 1.040; NaS, neutral Sodium sulfonate of average molecular weight 420; CaS N, neutral Calcium sulfonate of average molecular weight 800; CaS400, overbased Calcium sulfonate of average molecular weight 600. The numbers in Table 1 indicate final weight present in each formulated composition. All compositions shown have sufficient stability and functionality to be useable as antifouling agent according to the invention. The compositions of formulations 106, 107, 108 and 109 with 24-32% Barium sulfonate, 14-25% alkaline silicate solution, 12-23% propylene glycol and 25-45% mineral oil showed the overall best performance in terms of easy application on surfaces, dry coat cover and stability both in storage and in use with little initial release/loss of alkalinity when put into seawater.

TABLE-US-00001 TABLE 1 Examples of different ratios of the components of the invention that will function as antifouling preparation. Composition no 101 102 103 104 105 106 107 108 109 110 111 112 113 Sulfonate type BaS BaS BaS BaS BaS BaS BaS BaS NaS CaS N CaS N CaS400 CaS400 Sulfonate 45% 42% 31% 27% 16% 32% 28% 24% 32% 35% 22% 34% 26% Alkaline silicate 26% 18% 21% 25% 27% 14% 17% 20% 13% 16% 20% 23% 33% solution Propylene  3% 15% 17% 20% 23% 12% 16% 17% 10% 11% 13% 22% 24% glycol Mineral oil 26% 25% 31% 28% 34% 44% 38% 38% 45% 39% 45% 21% 16% 100%  100%  100%  100%  100%  100%  100%  100%  100%  100%  100%  100%  100%  Dry coat, g/m of 4.1 3.5 3.5 3.5 3.1 3.5 3.1 3.5 2.5 3.1 6.5 7.5 8.5 4 mm rope Separation in Some Some Yes Yes Yes No No No No Some Some Yes Yes storage Viscosity of Soft Soft Soft Soft Fluid Fluid Fluid Fluid Fluid Thick Thick Thick Thick paste

Example 2

[0072] This example as shown in FIG. 1A, demonstrates the function of the invention from testing of the leaching of alkalinity from a 40 cm of net line coated with the antifouling composition of formulation 110 of the invention during 30 day incubation in different water at 15° C. The leaching was monitored by measuring pH. The leaching of the alkaline silicate from the antifouling composition in pure water was about 25%, from 10% seawater it was about 3%, from 50% seawater it was about 0.5% and from 100% seawater it was about 0.1%. No precipitate could be detected in any of the test solutions, as monitored by light absorbance. Therefor the alkaline silicate remains inside the coated composition, probably in the form of an alkaline gel that explains, how together with the oily surface the composition can prevent fouling of surfaces in the marine environment.

Example 3

[0073] This example as shown in FIG. 1B, demonstrates the function of the invention from testing of the leaching of alkalinity from a 40 cm of net line coated with the antifouling composition of the invention. made with different sulfonate salts by up to 40 days incubation in seawater at 15° C. The leaching was monitored by measuring pH by up to 40 days incubation in different water at 15° C. The leaching was monitored by measuring pH. The compositions were made according to the invention Na sulfonate (formulation 109), Ba sulfonate (formulation 103), Ca sulfonate overbased 400 (formulation 112) and commercially available neutral Ca sulfonate premix sold as rust protection (formulation 110). The leaching of the alkaline silicate from the antifouling composition in seawater was as shown. The released alkali is partly neutralized with time polymerization, and neutralization from CO.sub.2 and other components in the seawater. The results show that divalent metal cations are more effective in maintaining the alkali inside the composition and show good stability in seawater.

[0074] Therefor the alkaline silicate remains inside the coated composition, probably in the form of an alkaline gel that explains, how together with the oily surface the composition can prevent fouling of surfaces in the marine environment. This effect is well demonstrated in FIG. 5 where two compositions were used to coat a 4 mm plastic rope and 40 of such rope was put into 190 ml of seawater and fresh water respectively. FIG. 5A contained composition of formulation 102 and FIG. 5B contained composition of formulation 104. As seen the coating remains stable in both cases in seawater and with less than 5% release of alkalinity of the total base in the composition, even after 30 days and no further release up to 6 months. On the other hand in fresh water the coating starts to swell and fall off the rope even after a few days and the alkalinity is released as seen by increased pH, where at least 50% of the alkalinity is released from the composition with formulation 102 (FIG. 5B and 100% release of alkalinity from the composition with formulation 104 (FIG. 5A).

Example 4

[0075] This example as shown in FIG. 2, demonstrates the non-toxicity function of the composition with formulation 110 of the invention from testing of leachate in growth medium of algae with a standard toxicity testing method as described by Ytreberg et al. (2010). The examples demonstrate that the composition and method of the present invention is non-toxic and environmentally friendly, since the leachate, even up to 30% in the growth medium, showed no inhibitory effects on the growth of the test-algae. As comparison it was shown that a standard copper-containing antifouling paint showed growth inhibition when the respective leachate used was more than 1% in the growth medium.

Example 5

[0076] This example demonstrates the antifouling function of the invention where plastic plates were coated with the composition according to formulation 102 and formulation 104 of the invention and incubated in seawater in natural settings and in a non-polluted environment. The results as shown in FIG. 3 show initial settlement of algae and first settling of small blue mussel larvae after 50 days in the sea.

Example 6

[0077] This example demonstrates the antifouling function of the invention where aquaculture cage nets treated with the composition according to formulation 108 of the invention that were kept submerged in open sea for 50 days with only limited attachment of soft algae and no attachment of hard crustaceans and shells as were started to be observed on the plates seen in FIG. 4.

[0078] The examples of useful compositions demonstrated and tested in Table 1 are good representations of possible and tested compositions that can be useful and fall within the scope of the present invention. Due to their overall chemical composition, viscosity and ease of use, the other compositions shown in Table 1, as well as several related variations are expected to show similar results as shown in Examples 2-6.

REFERENCES

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