Claims:CLAIMS
1. A water based self-cross linkable acrylic latex, the latex comprising:
a reaction product of:
a mixture of ethylenically unsaturated monomers;
diacetone acrylamide (DAAM);
ureido methacrylate; and
cyclo hexyl methacrylate (CHMA), wherein the latex is configured to be coated on a plurality of metal substrates, and wherein the latex is free of phosphates, chromates, fluoropolymers, or combinations thereof.

2. The latex of claim 1, wherein ureido methacrylate is N-(2-ethacryloyloxyethyl) ethylene urea or ethylene ureum ethylene.

3. The latex of claim 1, wherein the ethylenically unsaturated monomers comprise acrylic acid, methacrylic acid, styrene, and esters of acrylic and methacrylic acid.

4. The latex of claim 3, wherein the esters of acrylic and methacrylic acid comprise n-butyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth) acrylate, cycloalkyl (meth)acrylates, cyclohexyl methacrylate (CHMA), 2-ethyl hexyl acrylate, or combinations thereof.

5. The latex of claim 3, wherein the styrene comprises normal styrene, a-methyl styrene, tert-butyl styrene, or combinations thereof.

6. The latex of claim 1, further comprising vinyltrimethoxysilane (VTMO).

7. The latex of claim 1, wherein CHMA is present in 5-15 wt%, DAAM-ADH is present in 0.1-0.5 wt% and ureido methacrylate is present in 0.1-1 wt%.

8. The latex of claim 1, wherein the plurality of metal substrates comprises hot dipped galvanized steel, electro galvanized steel, cold rolled steel, aluminized steel, aluminium or combinations thereof.

9. The latex of claim 1, wherein the latex is configured to adhere to the plurality of metal substrates in absence of external additives.

10. The latex of claim 2, wherein methylmethacrylate of ethylene ureum ethylmethacrylate and vinyltrimethoxysilane are configured to provide adhesion when coated on the plurality of metal substrates.

11. The latex of claim 1, wherein the latex is configured to provide corrosion resistance to the plurality of metal substrates in absence of anti-corrosive agents, an additional surface treatment, or combinations thereof.

12. The latex of claim 11, wherein the anti-corrosive agents comprise phosphates, chromates, fluoropolymers, or combinations thereof.

13. The latex of claim 11, wherein the additional surface treatment comprises phosphatation or chromatation.

14. The latex of claim 1, wherein the latex is used as a primer or as a top coat formulation on the plurality of metal substrates.

15. The latex of claim 1, wherein the latex has a salt spray resistance of at least 500 hrs.

16. The latex of claim 1, wherein the latex has about 40 wt % to about 50 wt% of non-volatile material (NVM).

17. The latex of claim 1, wherein the latex comprises particles having a particle size of 0.1 micron to about 0.3 microns.

18. A process for making water based self-cross linkable acrylic latex, the process comprising:
forming an aqueous monomer pre-emulsion by adding ethylenically unsaturated monomers to an aqueous composition comprising a surfactant mixture of reactive anionic and non-ionic emulsifiers;
charging a first portion of the aqueous monomer pre-emulsion and a thermal initiator to a reactor to produce a seed latex;
adding diacetone acrylamide (DAAM) to a second portion of the aqueous monomer pre-emulsion to form a mixture;
subsequently adding the mixture to the reactor;
adding cyclo hexyl methacrylate (CHMA) to the reactor after a first period of time; and
adding ureido methacrylate to the reactor after a second period of time to form a reactor product.

19. The process of claim 18, further comprising adding vinyltrimethoxysilane (VTMO) to the pre-emulsion after a first period of time.

20. The process of claim 18, wherein the ethylenically unsaturated monomers comprise n-butyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth) acrylate, cycloalkyl (meth)acrylates, styrene, cyclohexyl methacrylate (CHMA), 2-ethyl hexyl acrylate, acrylic acid and methacrylic acid.

21. The process of claim 18, wherein the first period of time is about 60 minutes to about 120 minutes and the second period of time is about 150 minutes to about 200 minutes.

22. The process of claim 18, wherein charging the first portion comprises charging about 1 wt% to about 10 wt% of the aqueous monomer pre-emulsion.

23. The process of claim 18, wherein the formation of the latex is carried out in absence of anti-corrosive pigments, polyvalent metal complexes, and fluoropolymers.

, Description:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(Section 10, rule 13)

“SELF-CROSS LINKABLE LATEX COPOLYMER FOR METAL COATING”

Asian Paints Limited
Asian Paint Research and Technology Centre, Plot No. C -3B/1. TTC Industrial Area, MIDC Pawane, Thane Belapur Road, Navi Mumbai – 400703

The following specification particularly describes the invention and the manner in which it is to be performed

SELF-CROSS LINKABLE LATEX COPOLYMER FOR METAL COATING

FIELD
[001] Embodiments generally relate to metal coatings, and more particularly to a metal coating having a self-cross linkable latex copolymer.

BACKGROUND
[002] Water based latexes are often used as metal coatings over solvent borne system due to reduced volatile organic compounds (VOC). However, the existing technologies include certain materials/functionalities such as phosphate, chromate, fluoropolymer in the polymer backbone of the latex to impart corrosion resistance property.
[003] Other existing technologies use anti-corrosive pigments or polyvalent metal complexes either in the latexes or in the metal coatings to achieve corrosion resistance. Alkyd emulsion or chlorinated resin are sometimes used for metal coating applications.
[004] Some technologies use external adhesion promoters such as silanes, for achieving polymer adhesion on metal substrates such as galvanized steel and cold rolled steel.
[005] There is a need for a water-based latex that can provide corrosion resistance as well as adhesion without using external additives and surface treatment complexes/chemicals.
SUMMARY
[006] The following summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, example embodiments, and features described, further aspects, example embodiments, and features will become apparent by reference to the drawings and the following detailed description. Example embodiments provide an in-store customer tracking and engagement system.
[007] Briefly, according to an example embodiment, a water based self-cross linkable acrylic latex is provided. The latex includes a reaction product of a mixture of ethylenically unsaturated monomers, diacetone acrylamide (DAAM), ureido methacrylate and cyclo hexyl methacrylate (CHMA). The latex may be coated on a plurality of metal substrates and is free of phosphates, chromates, fluoropolymers, or combinations thereof.
[008] According to another example embodiment, a process for making water based self-cross linkable acrylic latex is provided. The process includes forming an aqueous monomer pre-emulsion by adding ethylenically unsaturated monomers to an aqueous composition comprising a surfactant mixture of reactive anionic and non-ionic emulsifiers, charging a first portion of the aqueous monomer pre-emulsion and a thermal initiator to a reactor to produce a seed latex, adding diacetone acrylamide (DAAM) to a second portion of the aqueous monomer pre-emulsion to form a mixture, subsequently adding the mixture to the reactor, adding cyclo hexyl methacrylate (CHMA), to the pre-emulsion after a first period of time, and adding ureido methacrylate to the pre-emulsion after a second period of time to form a reactor product.
BRIEF DESCRIPTION OF THE FIGURES
[009] These and other features, aspects, and advantages of the example embodiments will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
[0010] FIG. 1 depicts a flow diagram for making a water based self-cross linkable acrylic latex;
[0011] FIG. 2 depicts results of salt spray test of the latex after 500 hours;
[0012] FIG. 3 depicts results of salt spray and humidity tests of paint samples made with the latex after 500 hours;
[0013] FIG. 4 depicts comparative results of salt spray test of paint samples made with the latex and commercially existing paint by ATSM B117;
[0014] FIG. 5 depicts results of adhesion test by ASTM D 3359 after 2 days; and
[0015] FIG. 6 depicts a rating given to samples for an adhesion test (ASTM D3359).

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0016] This disclosure is not limited to the particular systems, devices and methods described, as these may vary. The terminology used in the description is for the purpose of describing the particular versions or embodiments only and is not intended to limit the scope.
[0017] Water based self-cross linkable acrylic latex disclosed herewith has corrosion resistance, humidity resistance and adheres on a wide variety of metal substrates such as mild steel, blasted mild steel, hot dipped galvanized steel, galvanized iron, and cold rolled steel. The process described herein does not use anti corrosive pigments, polyvalent metal complexes, alkyd emulsions, fluoropolymer or phosphate moieties. Further, the process does not use specific surface treatments such as phosphatation or chromatation and does not use external adhesion promoters to achieve adhesion on metal substrates.
[0018] FIG. 1 depicts a flow diagram for an illustrative method 100 to form a water based self-cross linkable acrylic latex. At block 102, an aqueous monomer pre-emulsion is formed by adding ethylenically unsaturated monomers to an aqueous composition comprising a surfactant mixture of reactive anionic and non-ionic emulsifiers. Ethylenically unsaturated monomers may comprise n-butyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth) acrylate, cycloalkyl (meth)acrylates, styrene, cyclohexyl methacrylate (CHMA), 2-ethyl hexyl acrylate, acrylic acid and methacrylic acid. The aqueous composition of surfactant mixture of reactive anionic and non-ionic emulsifiers may stabilize the pre-emulsion.
[0019] At block 104, a first portion of the aqueous monomer pre-emulsion and a thermal initiator were charged into a reactor to produce a seed latex. At block 106, diacetone acrylamide (DAAM) was added to a second portion of the aqueous monomer pre-emulsion to form a mixture. The mixture was subsequently added to the reactor. At block 108, cyclo hexyl methacrylate (CHMA) was added to the reactor after a first period of time. At block 110, ureido methacrylate was added to the reactor after a second period of time to form a reactor product, i.e., the water based self-cross linkable acrylic latex. The latex had corrosion resistance and humidity resistance. The latex adhered on a wide variety of metal substrates such as mild steel, blasted mild steel, hot dipped galvanized steel, galvanized iron, and cold rolled steel.
[0020] FIG.2 shows results of a salt spray test carried out on a panel coated with the latex. The salt spray test is a corrosion testing method that uses high-saline environments to measure the corrosion resistance of any coating. Here, a 5% NaCl solution was sprayed against the panel coated with the latex and was heated at a temperature of about 35° C. Further, the corrosion resistance was evaluated in terms of a period of time till appearance of corrosion on the panel. The latex prepared in accordance with the present technique did not give rise to corrosion even after 500 hours in the salt spray test.
[0021] FIG. 3 shows the results of salt spray test and humidity test of paint samples made with the latex after 500 hours. Paint samples using the latex were coated on a panel and the panel was tested against salt spray. The panels were exposed to humidity test. The panel coated with the latex did not give rise to corrosion even after 500 hours of salt spray and humidity tests.
[0022] FIG.4 shows the comparative results of salt spray test between a paint using the developed latex and a commercially existing paint. As observed, the panel coated with the latex did not give rise to corrosion even after 500 hours whereas the commercial paint failed to show the corrosion resistance.
[0023] FIG. 5 shows the results of adhesion test by ASTM D 3359 after 2 days. This test requires scribing the coated specimens to form a grid of twenty-five 2 mm×2 mm squares. Elcometer ASTM D3359 tape was applied to the surface, pressed down and stripped sharply away at an angle of 90° to the surface. The test was repeated three times, using fresh tape each time. Removal of any square of coating is considered an adhesion failure, and 100% adhesion indicates no removal of coating from any square. Elcometer ASTM D3359 tape having an acrylic pressure-sensitive adhesive were used in the following tests. The crosshatch adhesion tests were conducted at ambient conditions (about 20°C./50% relative humidity) and after aging for 100 hours at 35° C./95% relative humidity. FIG. 6 shows a rating system given for adhesion from 0B to 5B, indicating 5B-excellent, 4B-good, 3B-satisfactory and rating below 2B was considered as an adhesion failure.

EXAMPLES
[0024] The present invention will be described below in further detail with examples and comparative examples thereof, but it is noted that the present invention is by no means intended to be limited to these examples.
Example 1
Synthesis of latex
[0025] Table 1 presents the ingreditents used at different stages of synthesis of the latex along with the quantities used. Pre-emulsion was prepared in a reaction flask by mixing monomers styrene, cyclohexyl methacrylate (CHMA), 2-ethyl hexyl acrylate (2-EHA) and methacrylic acid. The pre-emulsion was stabilized with de-mineralized water and a small quantity of reactive, anionic and non-ionic surfactants. 0.15 gm of DOWFAX 2A1 and 19.5 gm de-mineralized water were added to a reactor and were heated to a temperature of around 80o C to 82o C. At this temperature, a first portion (around 3 %) of the pre-emulsion from the reaction flask was added as a seed to initiate the reaction in the reactor. Sodium bicarbonate buffer solution was added after adding the seed pre-emulsion. Potassium persulfate was used as a thermal initiator. Simultaneously, diacetone acrylamide (DAAM) was added to a second portion of the pre-emulsion to form a mixture in a reaction kettle. After completion of initiation in the reactor, the mixture from the reaction kettle was added to the reactor for about 240 minutes. During reaction, at different intervals of time, specialty monomers were added to the reactor. After 60 minutes of reaction, vinyl trimethoxy silane (VTMO) was added and after 150 minutes of reaction, ureido methacrylate (Visiomer MEEU 50W) was added to the pre-emulsion.
[0026] After complete addition of the specialty monomers, the reaction was held for 5 to 10 minutes with subsequent addition of a chaser catalyst for digesting the reactor contents. ATPOL E-5731/ 70N, t- butyl hydroperoxide, and sodium formaldehyde sulphoxalate in de-mineralized water were used as chaser/digestion catalysts. During the digestion, the temperature was maintained at around 80o C for 45-60 minutes. After completion of the digestion, the reactor was cooled to room temperature. Post additive materials such as an aqueous mixture of an in-can preservative, a de-foamer, adipic dihydrazide, an anionic surfactant and liquor ammonia were added to the reactor. The batch was then discharged, and the emulsion properties were checked. The emulsion properties are presented in Table 2. The viscosity of the emulsion was 150-350 cp, measured using BROOKFIELD KU-3 Viscometer at 25.0°C, ± 0.1°C.
TABLE 1

SR.NO Ingredients Kg
Pre-emulsion in reaction flask
1 De Mineralised Water 17.70
2 Reactive surfactants ADEKA SR 20 0.30
3 Anionic surfactants DOWFAX 2A1 0.15
4 Non-ionic surfactants ATPOL E-5731 /70N 0.60
5 STYRENE MONOMER 17.80
6 CYCLOHEXYL METHACRYLATE 10.00
7 2-ETHYL HEXYL ACRYLATE MONOMER 19.10
8 Glacial Methacrylic acid 1.20
In reaction Kettle
9 DIACETONE ACRYLAMIDE 0.20
Second portion of Pre-emulsion
Reactor charge
10 De Mineralised Water 19.50
11 Anionic surfactants DOWFAX 2A1 0.15
First portion (3%) of Pre-emulsion
12 POTASSIUM PERSULPHATE 0.15

13 VTMO 0.40
14 VISIOMER MEEU 50 W 0.30
Buffer Solution
15 De Mineralised Water 2.10
16 Buffer SODIUM BICARBONATE 0.20
Initiator Solution
17 De Mineralised Water 3.30
18 Initiator POTASSIUM PERSULPHATE 0.12
Water for flushing
19 De Mineralised Water 1.00
Chaser catalyst
20 De Mineralised Water 0.50
21 Non-ionic surfactants ATPOL E-5731/ 70N 0.05
22 t- BUTYL HYDEROPEROXIDE 0.04
23 De Mineralised Water 0.50
24 SODIUM FORMALDEHYDE SULPHOXLATE 0.04
Post Additives
25 In-can preservative Kathone LX 150 0.20
26 Defoamer TEGOFOAMEX K3 18% IN WATER 0.02
27 ADIPIC DIHYDRAZIDE 0.10
28 Anionic surfactants DOWFAX 2A1 0.05
29 LIQUOR AMMONIA 1.00
30 De Mineralised Water 3.23
Total 100.00

TABLE 2

% Non-Volatile Matter 48-50 %
Viscosity 150-350 cp
Particle size 0.1- 0.250 micron
pH 8.5-10
Tg by DSC 20-25 o C

[0027] Different experiments were carried out to establish the effect of presence and absence of specialty monomer and their stage of addition on desired properties of adhesion and corrosion resistance.
Experiment No. 1
[0028] In this experiment, diacetone acrylamide, Adipic dihydrazie (ADH) and ureido methacrylate were not added in the synthesis of the latex. Though the panel coated with the latex did not rise corrosion until after 500 hours of salt spray, the panel failed the humidity test. A heavy whitening of the coating on the panel was observed. Next, the panel was coated with a paint that includes the latex synthesized without diacetone acrylamide, ADH and ureido methacrylate. The panel with the paint did not show corrosion even after 500 hours of salt spray but failed the humidity test. Low sheen of the panel was observed.
Experiment No. 2
[0029] In this experiment, ureido methacrylate was not added in the synthesis of the latex. The panel coated with the latex failed in 150 hours of salt spray and the humidity test. Next, the panel was coated with a paint that includes the latex synthesized without ureido methacrylate. The panel with the paint failed in 44 hours of salt spray and humidity tests.
Experiment No. 3
[0030] In this experiment, diacetone acrylamide and ADH were not added in the synthesis of the latex. The panel coated with the latex failed in 150 hours of salt spray and the humidity test. Next, the panel was coated with a paint that includes the latex synthesized without diacetone acrylamide and ADH. The panel with the paint failed in 44 hours of salt spray and humidity tests.
Experiment No. 4
[0031] In this experiment, diacetone acrylamide, ADH and ureido methacrylate were added together in the beginning of the synthesis of the latex i.e., at the pre-emulsion stage. The panel coated with the latex did not rise corrosion until after 500 hours of salt spray and humidity tests. Next, the panel was coated with a paint that includes the latex synthesized by adding diacetone acrylamide, ADH and ureido methacrylate at the pre-emulsion stage. The panel with the paint failed both the salt spray and the humidity tests. The panel showed low sheen.
Experiment No. 5
[0032] In this experiment, except cyclohexyl methacrylate (CHMA), all other monomers were added in the synthesis of the latex. The panel coated with the latex did not rise corrosion until after 500 hours of salt spray. However, the panel failed the humidity test. A heavy whitening of the coating on the panel was observed. Next, the panel was coated with a paint that includes the latex synthesized without cyclohexyl methacrylate. The panel with the paint passed the salt spray test but failed the humidity test. Heavy blister formation was observed on the panel.
[0033] Table 3 shows the summarized results of all the experiments. It is clear from these results that presence of DAAM, ADH, MEEU, and CHMA and the stage of addition play an important role on the properties of the latex. Adding DAAM, ADH, MEEU, and CHMA at a particular time interval yielded the desired latex.

TABLE 3

Batch no Variable Latex coated as a film Paint film
DFT Salt spray Humidity DFT Salt spray Humidity
Example 1
(DAAM ADH + MEEU + CHMA)
[added in pre-emulsion at different intervals] 100-110 Pass 500 hr Pass 500 hr 130-140 Pass 500 hr Pass 500 hr
DOE 1 Without DAAM ADH & MEEU 100-110 Pass 500 hr Failed (due to heavy whitening of film) 130-140 Pass 500 hr Failed (low sheen observed)
DOE 2 Without MEEU 100-110 Fails in 150 hr Fails in 150 hr 130-140 Fails in 44 hr Fails in 44 hr
DOE 3 Without DAAM ADH 100-110 Fails in 150 hr Fails in 150 hr 130-140 Fails in 44 hr Fails in 44 hr
DOE 4 All (MEEU & DAAM) added together (beginning of the reaction added in pre-emulsion) 100-110 Pass 500 hr Pass 500 hr 130-140 poor salt spray Failed (due to low sheen)
DOE 5 Without CHMA 100-110 Pass 500 hr Highest whitening 130-140 Pass 500 hr Failed (Blisters formation)
[0034] The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods, reagents, compounds, compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
[0035] While various compositions, methods, and devices are described in terms of “comprising” various components or steps (interpreted as meaning “including, but not limited to”), the compositions, methods, and devices can also “consist essentially of” or “consist of” the various components and steps, and such terminology should be interpreted as defining essentially closed-member groups.
[0036] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
[0037] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases at least one and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases one or more or at least one and indefinite articles such as “a” or an (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
[0038] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.
[0039] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.
[0040] Various of the above-disclosed and other features and functions, or alternatives thereof, may be combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, each of which is also intended to be encompassed by the disclosed embodiments.
[0041] While only certain features of several embodiments have been illustrated, and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of inventive concepts.
[0042] The afore-mentioned description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the example embodiments is described above as having certain features, any one or more of those features described with respect to any example embodiment of the disclosure may be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described example embodiments are not mutually exclusive, and permutations of one or more example embodiments with one another remain within the scope of this disclosure.