GREEN CATIONIZATION AGENT

Abstract

A compound having Formula (I) or Formula (II):

##STR00001##

or a mixture thereof,

in which R is —H; —CH.sub.3; —CH—(CH.sub.3).sub.2; —CH.sub.2—CH—(CH.sub.3).sub.2; —CH—(CH.sub.3)—CH.sub.2—CH.sub.3; —CH.sub.2—(C.sub.6H.sub.5); —CH.sub.2—(3-indole); —CH.sub.2—CH.sub.2—S—CH.sub.3; —CH.sub.2—OH; —CH—(CH.sub.3)—OH; —CH.sub.2—SH; —CH.sub.2-(p-C.sub.6H.sub.40H); —CH.sub.2—CH.sub.2—CH.sub.2—CH.sub.2—NH.sub.2; —CH.sub.2—CO—NH.sub.2; —CH.sub.2—CH.sub.2—CO—NH.sub.2; —CH.sub.2—CH.sub.2—COOH; —CH.sub.2—COOH; or —CH.sub.2—CH.sub.2—NH—C═NH.sub.2(NH.sub.2);

and X is a suitable non-interfering anion, a process for making the compound having Formula (I) or Formula (II), and a process for reacting the compound having Formula (I) or Formula (II) or a mixture thereof with a (poly)saccharide to form a cationized (poly)saccharide.

Claims

1. A compound having Formula (I) or Formula (II): ##STR00015## or a mixture of both a compound having Formula (I) and a compound having Formula (II), wherein R is —H; —CH.sub.3; —CH—(CH.sub.3).sub.2; —CH.sub.2—CH—(CH.sub.3).sub.2; —CH—(CH.sub.3)—CH.sub.2—CH.sub.3; —CH.sub.2—(C.sub.6H.sub.5); —CH.sub.2-(3-indole); —CH.sub.2—CH.sub.2—S—CH.sub.3; —CH.sub.2—OH; —CH—(CH.sub.3)—OH; —CH.sub.2—SH; —CH.sub.2-(p-C.sub.6H.sub.40H); —CH.sub.2—CH.sub.2—CH.sub.2—CH.sub.2—NH.sub.2; —CH.sub.2—CO—NH.sub.2; —CH.sub.2—CH.sub.2—CO—NH.sub.2; —CH.sub.2—CH.sub.2—COOH; —CH.sub.2—COOH; or —CH.sub.2—CH.sub.2—NH—C═NH.sub.2(NH.sub.2); and X is a suitable non-interfering anion.

2. A process for producing the compound having Formula (I) as defined in claim 1, comprising: providing a first compound having either Formula (III) or Formula (IIIa): ##STR00016## wherein R is as defined in claim 1; providing epichlorohydrin, having formula: ##STR00017## or providing 1,3-dichloro-2-propanol, having formula:
ClCH.sub.2—CH(OH)—CH.sub.2Cl or providing a mixture of both epichlorohydrin and 1,3-dichloro-2-propanol; and reacting the first compound with the epichlorohydrin or the 1,3-dichloro-2-propanol or the mixture of epichlorohydrin and 1,3-dichloro-2-propanol under suitable esterification conditions to form the compound having Formula (I).

3. A process for producing the compound having Formula (II) as defined in claim 1, comprising: providing a first compound having either Formula (III) or Formula (ilila): ##STR00018## wherein R is as defined in claim 1; providing epichlorohydrin, having formula: ##STR00019## or providing 1,3-dichloro-2-propanol, having formula:
ClCH.sub.2—CH(OH)—CH.sub.2Cl or providing a mixture of both epichlorohydrin and 1,3-dichloro-2-propanol; reacting the first compound with the epichlorohydrin or the 1,3-dichloro-2-propanol or the mixture of epichlorohydrin and 1,3-dichloro-2-propanol under suitable esterification conditions to form the compound having Formula (I), and converting the compound having Formula (I) to the compound having Formula (II) by an epoxidation reaction.

4. A cationic (poly)saccharide comprising a reaction product of the compound having the Formula (I) or the compound having the Formula (II) or a mixture of both the compound having Formula (I) and the compound having Formula (II) of claim 1 with a (poly)saccharide.

5. The cationic (poly)saccharide according to claim 4, wherein the (poly)saccharide is a starch, a guar, or a cellulose.

6. The cationic (poly)saccharide according to claim 4, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (I).

7. The cationic (poly)saccharide according to claim 5, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (I).

8. The cationic (poly)saccharide according to claim 4, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (II).

9. The cationic (poly)saccharide according to claim 5, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (II).

10. The cationic (poly)saccharide according to claim 4, wherein the cationic (polysaccharide) comprises the reaction product made with the mixture of both the compound having Formula (I) and the compound having Formula (II).

11. The cationic (poly)saccharide according to claim 5, wherein the cationic (polysaccharide) comprises the reaction product made with the mixture of both the compound having Formula (I) and the compound having Formula (II).

12. A process for producing a cationic (poly)saccharide comprising: providing a suitable (poly)saccharide; providing the compound having Formula (I) or the compound having Formula (II) or a mixture of both the compound having Formula (I) and the compound having Formula (II) as defined in claim 1; reacting the suitable (poly)saccharide with the compound having Formula (I) or the compound having Formula (II) or the mixture of both the compound having Formula (I) and the compound having Formula (II) under suitable conditions to result in reaction to form the cationic (poly)saccharide.

13. The process according to claim 12, wherein the (poly)saccharide is a starch, a guar, or a cellulose.

14. The process according to claim 12, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (I).

15. The process according to claim 13, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (I).

16. The process according to claim 12, wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (II).

17. The process according to claim 13 wherein the cationic (polysaccharide) comprises the reaction product made with the compound having Formula (II).

18. The process according to claim 12 wherein the cationic (polysaccharide) comprises the reaction product made with the mixture of both the compound having Formula (I) and the compound having Formula (II).

19. The process according to claim 13 wherein the cationic (polysaccharide) comprises the reaction product made with the mixture of both the compound having Formula (I) and the compound having Formula (II).

Description

BRIEF DESCRIPTION OF THE FIGURES

[0059] FIG. 1 shows overlapping FTIR scans for betaine and a compound having Formula (I) made from betaine, according to an embodiment of the present invention.

[0060] FIG. 2 shows overlapping FTIR scans for an unmodified starch and a starch modified with a compound having Formula (I) made from betaine, according to an embodiment of the present invention.

[0061] FIG. 3 shows overlapping FTIR scans for an unmodified guar and a guar modified with a compound having Formula (I) made from betaine, according to an embodiment of the present invention.

[0062] FIG. 4 shows a mass spectra for a betaine reagent having Formula (I) made from betaine, according to an embodiment of the present invention.

DETAILED DESCRIPTION

[0063] According to embodiments of the present invention, a betaine or betaine-type compound or a quaternized amino acid is used to react with epichlorohydrin, 1,3-dichloro-2-propranol, or a mixture of both, to form an ester linkage between these reactants. The resulting compound, referred to herein as Formula (I) can then be either further treated to form an epoxy group from the chlorohydrin, which forms a compound according to Formula (II); or, alternatively, the Formula (I) compound can be used directly to react with a target moiety, e.g., starch, guar, or other (poly)saccharide, to cationize the target moiety. In the alternate option, if the compound having Formula (II) is formed, the compound having Formula (II) can be used to cationize the target moiety.

[0064] In one embodiment, the term “target moiety”, singular or plural, does not include surfactants. In one embodiment, the term “target moiety”, singular or plural, does not include surfactants or any moieties other than the target moiety(ies) identified positively herein, i.e., (poly)saccharides.

[0065] In one embodiment, the present invention begins with a betaine-type or Zwitterionic structure, which may include betaine, betaine HCI, a quaternized amino acid, or a quaternized amino acid hydrogen chloride salt. The betaine-type structure is generalized in the general Formula (III) or the general Formula (IIIa):

##STR00010##

wherein, in Formula (III), X is a suitable, non-interfering anion, and R is H or the organic portion of a natural amino acid as defined herein. As will be understood, the Formula (III) moiety is the HX form of the quaternary amino acid or betaine, and the Formula (IIIa) moiety is the free or “natural” form of the quaternary compound of betaine.

[0066] It is noted that the term “zwitterion” or “zwitter-ion” only applies to the betaine type compounds herein, since amino acids do not occur naturally as zwitterions.

[0067] Where R is H, the compound having Formula (III) or Formula (IIIa) is betaine hydrochloride, or betaine HCI, and as will be understood, where R is H, the underlying amino acid is glycine. This betaine also may be referred to as “glycine betaine”.

[0068] Where R is the organic portion of an amino acid, R (and corresponding amino acid) may be —CH.sub.3 (alanine); —CH—(CH.sub.3).sub.2 (valine); —CH.sub.2—CH—(CH.sub.3).sub.2 (leucine); —CH—(CH.sub.3)—CH.sub.2—CH.sub.3 (isoleucine); —CH.sub.2—(C.sub.6H.sub.5) (phenylalanine); —CH.sub.2-(3-indole) (tryptophan); —CH.sub.2—CH.sub.2—S—CH.sub.3 (methionine); —CH.sub.2—OH (serine); —CH—(CH.sub.3)—OH (threonine); —CH.sub.2—SH (cysteine); —CH.sub.2-(p-C.sub.6H.sub.40H) (tyrosine); —CH.sub.2—CH.sub.2—CH.sub.2—CH.sub.2—NH.sub.2 (lysine); —CH.sub.2—CO—NH.sub.2 (asparagine); —CH.sub.2—CH.sub.2—CO—NH.sub.2 (glutamine); —CH.sub.2—CH.sub.2—COOH (glutamic acid); —CH.sub.2—COOH (aspartic acid); or —CH.sub.2—CH.sub.2—NH—C═NH.sub.2(NH.sub.2) (arginine).

[0069] In one embodiment, R is —H; —CH.sub.3; —CH—(CH.sub.3)—CH.sub.2—CH.sub.3; —CH.sub.2—CH—(CH.sub.3).sub.2; —CH—(CH.sub.3).sub.2; —CH.sub.2—CH.sub.2—CH.sub.2—CH.sub.2—NH.sub.2; —CH.sub.2—CO—NH.sub.2; or —CH.sub.2—CH.sub.2—CO—NH.sub.2.

[0070] Herein, reference to the compound having Formula (III) is considered to include the compound having Formula (IIIa), except if specifically differentiated in the context of the disclosure. For example, since the compound of Formula (III) may be prepared from the compound having Formula (IIIa), simply by forming the HX salt, where X is a suitable non-interfering anion as defined herein, they may be considered for many purposes the same compound, especially in solution or in a reaction.

[0071] As noted above for all the compounds according to Formula (I), Formula (II), Formula (III) and Formula (IIIa), the ammonium N atom may be quaternized with any independently selected C.sub.1-C.sub.4 alkyl group, which is preferably unbranched.

[0072] The compound having Formula (III) may be reacted with epichlorohydrin:

##STR00011##

such that the acid portion of the compound of Formula (III) reacts under suitable conditions with epichlorohydrin to form the compound of Formula (I), as shown in the following:

##STR00012##

using known reaction conditions. Such known reaction conditions include, for example, acid-catalyzed esterification reaction between the compound having Formula (III) and epichlorohydrin, and may also be carried out between the compound having Formula (III) and 1,2-dichloro-2-propanol. This reaction may be conducted, for example, at elevated temperature, with or without elevated or reduced pressure. Other known esterification conditions may be applied as suitable.

[0073] In one embodiment, the chlorohydrin ester, having general Formula (I) shown above, may be converted into the epoxy analog by known procedures. A known procedure for converting a chlorohydrin to the epoxy analog is to heat the chlorohydrin in the presence of an organic co-solvent and a base, such as sodium hydroxide or an organic base, to form the epoxy analog, sodium chloride and water.

[0074] In accordance with the present invention, the compound having Formula (I) is converted into the compound having Formula (II) by reaction under such pH regulated conditions of alkali hydroxide or organic base and heat.

[0075] By virtue of the ester linkage, this cationization agent, when used to form a cationic (poly)saccharide, produces a cationic (poly)saccharide that is readily biodegradable. Cationization of other suitable target moieties produces biodegradable products, as well, for the same reason—that is, it includes the ester portion of the product molecule, which is considered to enable ready biodegradation through hydrolysis of the ester moiety.

[0076] The compounds having Formula (I) or Formula (II) are used, in accordance with the present invention, to form a cationic (poly)saccharide or other cationic target moiety, such as cationic starch, cationic guar, or a cationic cellulose polymer.

[0077] Depicted below are examples of a cationic (poly)saccharide made according to the prior art, and a cationic (poly)saccharide made in accordance with the present invention, both using a starch backbone as example. The distinction that provides biodegradability is considered to be the ester linkage in the (poly)saccharide made according to the present invention. As defined herein, X is a suitable, non-interfering anion.

##STR00013##

[0078] In both of these example cationic starches, the cationizing agent has bonded to the starch via the 6-position oxygen atom on the glucose ring in the starch molecule depicted here. It is the presence of the ester linkage in the present invention cationic (poly)saccharide that is considered both novel and inventive and to render the resulting cationic starch biodegradable, in accordance with embodiments of the present invention.

[0079] As described herein, in the cationic (poly)saccharide, and other target moieties, made according to the present invention, R and X are as described in the foregoing descriptions.

[0080] The cationization reaction is carried out as needed to obtain the desired degree of substitution (DS) in the cationic (poly)saccharide product. As known in the art, various DS may be sought as appropriate, depending on, e.g., the intended use of the cationic (poly)saccharide.

Experimental

Preparation of Betaine*HCl salt solution

[0081] Pre-charge reactor with water and slowly add solid Betaine (preferred concentration of solution 20-40%). Slowly add one molar equivalent of HCl solution (35-37% concentration), keeping temperature between 20-30° C. 30 minutes after addition of the HCl solution, the aqueous solution containing Betaine*HCl can either be used directly or isolated in solid form via distillation. Isolated solid Betaine*HCl is redissolved in a polar solvent (preferably, a polar protic solvent).

Betaine Cationic Reagent

Based Upon Aqueous Betaine*HCl Solution

[0082] Pre-charge reactor with a 1 to 5 molar excess of epichlorohydrin, based upon the amount of betaine*HCl to be used.

[0083] Increase temperature to 40-120° C. (preferred, 60° C.-105° C.).

[0084] Slowly add the previously prepared Betaine*HCl solution over a 2 hour period.

[0085] Allow reaction time of 3 hours at these conditions.

[0086] Then, reduce the temperature of the reaction mixture to 20-25° C.

[0087] Measure pH level and adjust pH level appropriately.

pH level adjustment depends on the desired product.

2-(3-chloro-2-hydroxypropoxy)-N,N,N-trimethyl-2-oxoethanaminium chloride

[0088] Betaine (REAGENS™) solution pH level is adjusted to pH.sub.5-pH.sub.7 (preferred is pH 6) via slow addition of a diluted HCl solution (for example, preferably 5% HCl solution).

N,N,N-trimethyl-2-(oxiran-2-ylmethoxy)-2-oxoethanaminium chloride (betaine ‘GMAC’)

[0089] Extra attention should be applied for reducing the possibility of hydrolysis. Initially a measurement is done on the hydrolysable chloride content and HPLC analysis. Based upon ascertained results, calculated amount (1 to 1 ratio) of a dilute base (NaOH or organic base), which is slowly added under continuous temperature and pH monitoring, keeping pH level 8-10 during the addition and at a temperature 20-50° C.

Product work-up

[0090] Conduct phase separation and isolate the aqueous layer (=product stream). The aqueous solution containing the betaine cationic reagent is further purified, removing present organic impurities (e.g., epichlorohydrin, 1,2-dichloropropanol and 1,3-dichloropropanol) by multiple extraction/washing steps with a polar aprotic solvent (for example, methylethylketone is preferred).

[0091] After the purification step, residual trace amounts of the extraction solvent are removed via vacuum distillation.

Betaine Cationic Reagent Via Betaine Directly

[0092] Prepare a solution of betaine by dissolving the reactant in a polar solvent (preferably, a polar protic solvent).

[0093] Pre-charge reactor with a 1 to 10 molar excess of either (±)epichlorohydrin or 1,3-dichloro-2-propanol, based upon the amount of betaine used.

[0094] Increase temperature to 60° C. and slowly add the solution containing betaine to the reactor.

[0095] After addition, reaction temperature is increased to 90-150° C. (preferably 110° C.).

[0096] Let reaction mixture stir at set conditions for 8-24 hours (preferably 8 hours).

[0097] After reaction, pH level is measured and adjusted or maintained to pH 5-pH 7 (preferred pH 6) using, e.g., dilute HCl solution.

Product work-up

[0098] Similar to the example using Betaine*HCl, organic impurities formed (e.g., epichlorohydrin, 1,2-dichloropropanol and 1,3-dichloropropanol) are removed by multiple extraction/washing steps with a polar aprotic solvent (methylethylketone may be preferred).

[0099] After the purification step, residual trace amounts of the extraction solvent are removed via vacuum distillation.

Amino Acid Based Cationic Reagents

[0100] Cationic reagents based upon amino acids are prepared by a two step reaction. Initially the present amine groups are converted to tertiary ammonium groups by means of the Eschweiler-Clarke route. As noted, if multiple amine groups are present, any amine not to be reacted should be protected, as known in the art, prior to further steps. Taking 2-aminopropanoic acid (alanine) as an example, 2-aminopropanoic acid reacts with formalin (=aqueous solution of formaldehyde) to form an imine. Following the formation of the imine, formic acid is added to protonate the imine, thereby forming the secondary amine and carbon dioxide. This process is repeated once more, to provide the tertiary amine. Typical reaction temperature is 40-120° C.

[0101] This newly formed tertiary amine is quaternized by means of dosing with, e.g., methyl chloride gas, or other alkyl halide as appropriate, in the presence of a polar aprotic solvent (preferred solvent, acetonitrile).

[0102] The formed product, 1-carboxy-N,N,N-trimethylethanaminium chloride, having the structure shown below, is brought into water via a solvent switch.

##STR00014##

[0103] The second step in the process is similar to the process described above using Betaine: [0104] Prepare a solution of the quaternized amino acid (in this example, 1-carboxy-N,N,N-trimethylethanaminium chloride) by dissolving the it in a polar solvent (preferably, a polar protic solvent, e.g., water). [0105] Pre-charge the reactor with a 1 to 10 molar excess of either (±)epichlorohydrin or 1,3-dichloro-2-propanol, based upon the amount of quaternized amino acid used.

[0106] Increase temperature to 60° C. and slowly add the solution containing the quaternized amino acid to the reactor.

[0107] After addition, reaction temperature is increased to 90-150° C. (preferably 110° C.).

[0108] Allow the reaction mixture stir at set conditions for 8-24 hours (preferably 8 hours).

[0109] After the reaction mixture is stirred for the above time, the pH level is measured and adjusted or is maintained to pH 5-pH 7 (preferred pH 6) using, e.g., dilute HCl solution.

Product Work-Up

[0110] The organic impurities present in the aqueous reaction solution (e.g., epichlorohydrin, 1,2-dichloropropanol and/or 1,3-dichloropropanol) are removed by multiple extraction/washing steps with a polar aprotic solvent (preferred, e.g., methylethylketone). After the purification step, residual trace amounts of the extraction solvent are removed via vacuum distillation.

Example Process for Cationization of a (Poly)Saccharide

[0111] Pre-charge a reactor with solvent (water, isopropyl alcohol, acetone or a combination thereof); add appropriate amount of selected (poly)saccharide. [0112] Increase temperature to the range of 30-50° C. (preferred temperature is 37.5° C.) [0113] Add appropriate amount of sodium hydroxide (preferably a 5% solution) to obtain pH 9-11 (preferred is pH 10.5).

[0114] Allow reaction mixture to stir for 1-3 hours at these conditions.

[0115] Slowly add an appropriate amount of the cationic reagent according to Formula (I) or Formula (II). The appropriate amount is based on the selected, desired DS value in the cationized (poly)saccharide product. This amount can be readily determined by the skilled person. [0116] Let reaction mixture stir for 1-3 hours at set conditions. [0117] Measure pH level and, if needed, adjust to pH 8-10 (preferred is pH 9). [0118] Let reaction mixture stir at set conditions for 4-24 hours (preferred, 24 hours) Lower temperature to about 24° C. [0119] Adjust pH level to pH 5-7 (preferred is pH 6.5) [0120] Isolated cationic (poly)saccharide via vacuum filtration and wash three times with demineralized water or solvent (e.g. acetone or isopropyl alcohol) [0121] Dry obtained cationic (poly)saccharide via vacuum distillation or oven to remove residual solvent.

Example of a Shampoo Formulation Using Cationic Guar

[0122] The cationic guar, made by a process in accordance with the present invention, is the first ingredient introduced in the shampoo preparation, i.e., prior to the surfactants and other ingredients. The following steps, in order: [0123] With moderate agitation, slowly add the cationic guar into water with a propeller mixer. Continue to mix during 10 to 15 minutes until homogeneous. [0124] Adjust pH to 3-4 with lactic or citric acid before addition of high pH surfactant. [0125] First add the amphoteric and/or nonionic surfactants if present. Mix until homogeneous. [0126] Then add slowly the anionic surfactant with mixing. Mix until homogeneous. [0127] Add the remaining ingredients (preservatives, perfume, etc.) [0128] Add NaCl to adjust the final viscosity. Mix until homogeneous [0129] It is important to first add the amphoteric surfactants and then the anionic surfactants to avoid compatibility issues.

Example of a Shampoo Formulation

[0130]

TABLE-US-00001 INGREDIENT % w/w (AM) Water QS to volume Sodium coco sulfate 6.00 Cationic (poly)saccharide 0.50 Lauryl glucoside 4.00 Coco glucoside 2.50 Glycerin 3.00 Preservatives 0.60 Lactic Acid to pH 5.5-6.0 Sodium Chloride 1.50 (Note: coco is a mixture of fatty acids from coconut oil.)

[0131] The figures include FTIR scans comparing starting materials and reaction products to show evidence of the formation of the reaction products, and mass spectrum to show the molecular weight of the betaine-source cationizing agent, in accordance with embodiments of the present invention. Each figure is briefly described in the following paragraphs.

[0132] FIG. 1 shows overlapping FTIR scans for betaine and a compound having Formula (I) made from betaine, according to an embodiment of the present invention. The differences in the IR peaks show the characteristic peaks for the compound having Formula (I), as compared to the IR peaks for the unreacted betaine. It is noted, for example, that the peak at about 1750 cm.sup.−1 would correspond to the ester carbonyl group.

[0133] FIG. 2 shows overlapping FTIR scans for an unmodified starch and a starch modified with a compound having Formula (I) made from betaine to form a cationic starch, according to an embodiment of the present invention. As shown, the Kjeldahl nitrogen analysis shows the incorporation of the N atom from the betaine-source cationization reagent in the starch modified according to the present invention. The differences in the IR peaks show the characteristic peaks for the unmodified starch, as compared to the IR peaks for the starch modified according to an embodiment of the present invention. It is noted, for example, that the peak at about 1650 cm-1 would correspond to the C—N bonds in the betaine reagent added to the (poly)saccharide.

[0134] FIG. 3 shows overlapping FTIR scans for an unmodified guar and a guar modified with a compound having Formula (I) made from betaine, according to an embodiment of the present invention. As shown, the Kjeldahl nitrogen analysis shows the incorporation of the N atom from the betaine-source cationization reagent in the guar modified according to the present invention. The differences in the IR peaks show the characteristic peaks for the unmodified guar, as compared to the IR peaks for the guar modified according to an embodiment of the present invention. It is noted, for example, that the peak at about 1750 cm-1 would correspond to the ester carbonyl group.

[0135] FIG. 4 shows a mass spectra for a betaine reagent having Formula (I) made from betaine, according to an embodiment of the present invention. As shown, the cationic betaine-derived Betain REAGENS™ has molecular weight of 209.68, and the MS spectrum shows a prominent peak at 210, corresponding to the Betaine REAGENS™ cation plus a proton.

[0136] It is noted that, throughout the specification and claims, the numerical limits of the disclosed ranges and ratios may be combined, and are deemed to include all intervening values. Furthermore, all numerical values are deemed to be preceded by the modifier “about”, whether or not this term is specifically stated. Unless otherwise specified, all pressures are atmospheric and all temperatures are room temperature (about 20° C. to about 25° C.).

[0137] Furthermore, it should be appreciated that the process steps and structures described herein do not form a complete process flow for manufacturing products such as those described herein. The present invention can be practiced in conjunction with synthetic techniques currently used in the art, and only so much of the commonly practiced process steps are included as are necessary for an understanding of the present invention.

[0138] While the principles of the invention have been explained in relation to certain particular embodiments, and are provided for purposes of illustration, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims. The scope of the invention is limited only by the scope of the appended claims.