FIELD OF THE INVENTION

The present invention relates generally to the field of paint compositions and, more particularly, to methods for preparing waterborne paint compositions, suitable for application to a surface without pretreatment thereof.

BACKGROUND OF THE INVENTION

Paints have been made over thousands of years for application on various surfaces. However, many paints peel off, when exposed to sun. Certain paints require the sanding of a surface or other pre-treatment , prior to application of the paint. Some paints require the application of several coats and sometimes a different undercoat. The more steps required in the painting process, the more expensive and time- consuming the painting process is.

One particularly problematic field is that of painting non-flat surfaces and objects, such as wooden furniture. Often, a sanding step is required, followed by an undercoat, one or more paint coats and then a gloss or lacquer coat to provide a finish to the object.

Another problem in recent years is the components of the paint composition consisting of solvents and environmentally detrimental ingredients. These environmentally detrimental ingredients may include any one or more of a toxic metal, such as lead or cadmium, and a volatile organic compound (VOC) . These present hazards, both to the workers, who apply the paints to objects (high-concentrations, short or long exposure times) and to the consumers, who are exposed to low concentrations of the environmentally detrimental ingredients over the long term (such as if applied to pipelines, household goods, automobiles and the like) .

Volatile organic compounds were historically, used in many paint formulations. Typical solvents used in the paint industry included aliphatic hydrocarbons, ethyl acetate, glycol ethers, and acetone. Due to many recent regulations, coupled with cost and environmental effects, the paint and coating industries have moved increasingly away from organic- solvent based paints and coatings toward aqueous solvents- based paints and coatings. However, many of these still require sanding, undercoats and top-coats.

There is thus still a need to develop novel paint compositions, which are waterborne, cheap, and are compatible with a broad spectrum of surfaces. It would be highly advantageous to develop a waterborne paint composition, which required less pretreatment of an object surface with minimal coating layers.

SUMMARY OF THE INVENTION

It is an object of some aspects of the present invention to provide a paint composition for coating a surface without pre-treatment thereof.

It is another object of some aspects of the present invention to provide a paint composition for coating a surface without sanding thereof.

It is yet another object of some aspects of the present invention to provide a paint composition for coating a surface without requiring an undercoat application thereto.

In some embodiments of the present invention, improved methods are provided for producing a waterborne paint composition.

The present invention further pertains to waterborne paint compositions, which are storage stable.

The present invention further comprises a paint composition comprising: a) at least one inorganic powder in a concentration range of 5 to 40 wt%;

b) water in a concentration range of 5 to 40 wt%; c) at least one paint in a concentration range of 5 to 40 wt%; and d) at least one of a sealer and a lacquer in a concentration range of 5 to 40 wt%.

The present invention further comprises a waterborne paint composition comprising: a) at least one inorganic powder in a concentration range of 10 to 40 wt%; b) water in a concentration range of 10 to 40 wt%; c) at least one paint in a concentration range of 10 to 40 wt%; and d) at least one of a sealer and a lacquer in a concentration range of 10 to 40 wt%.

Furthermore, according to an embodiment of the present invention, the paint composition comprises at least one additive. The additive may be selected from at least one colorant, at least one dye, at least one pigment and at least one preservative. The paint composition may further comprise at least one hiding pigment, selected from, but not limited to, titanium dioxide, phthalo blue and red iron oxide.

The paint mixture and paint composition may comprise at least one additive acting as filler. The fillers are usually cheap and inert materials, such as, but not limited to diatomaceous earth, talc, lime, barytes and clay.

Additionally, according to an embodiment of the present invention, the composition is liquid in a temperature range of 4 to 40 °C.

Additionally, according to an embodiment of the present invention, the at least one colorant is selected from the group consisting of titanium dioxide, carbon black, iron oxide, zinc chromate, cadmium sulfide, chromium oxide, a sodium aluminum silicate complex, an ultramarine pigment, metal flakes, an azo pigment, a diazo pigment, phthalocyanine, a quinacridone pigment, a perylene pigment, isoindolinone, anthraquinone, thio-indigo, a solvent dye and combinations thereof . There is thus provided according to another embodiment of the present invention, a method for forming a paint composition, the method including;

a. combining at least one inorganic powder with water to form a mixture;

b. mixing said mixture with at least one paint to form a paint mixture; and

c. admixing said paint mixture with at least one of a sealer and a lacquer to form said paint composition .

Additionally, according to an embodiment of the present invention, the method further comprises adding at least one additive to at least one of said mixture, said paint mixture and said paint composition.

Moreover, according to an embodiment of the present invention, the admixing step induces size reduction of particles to a maximum of 1 to 20 microns.

There is thus provided according to an embodiment of the present invention, a paint composition for applying in one coat to a surface, the paint composition including;

a. water;

b. at least one inorganic particulate;

c. at least one paint; and

d. at least one of a sealer, a sealant and a lacquer.

Additionally, according to an embodiment of the present invention, the paint composition further includes at least one colorant.

Moreover, according to an embodiment of the present invention, the paint composition further includes at least one additive .

Furthermore, according to an embodiment of the present invention, the composition is liquid in a temperature range of 4 to 40 °C. Additionally, according to an embodiment of the present invention, the at least one inorganic particulate includes two inorganic powders.

Moreover, according to an embodiment of the present invention, the two inorganic powders include calcium carbonate and calcium sulfate.

Further, according to an embodiment of the present invention, the paint composition includes water, 10-20 wt %; calcium carbonate 5-15 wt%; calcium sulfate 5-15 wt%; 30-60% waterborne paint; and 10-20 wt % sealer.

Additionally, according to an embodiment of the present invention, the paint composition includes water, 10-20 wt %; calcium carbonate 5-15 wt%; calcium sulfate 5-15 wt%; 30-60% waterborne paint; and 10-20 wt % lacquer. Additionally, according to an embodiment of the present invention, the composition is suitable for coating a surface in one coat.

Moreover, according to an embodiment of the present invention, the surface is selected from a wooden surface, a glass surface, a polymeric surface, a plastic surface, a rubber surface, a metal surface, an iron surface, a bodily part, a wall, a ceiling and a floor.

Additionally, according to an embodiment of the present invention, the bodily part is selected from a nail, a tooth, a tusk, a hair, a skin, leather and a hide.

Furthermore, according to an embodiment of the present invention, the at least one colorant is selected from the group consisting of titanium dioxide, carbon black, iron oxide, zinc chromate, cadmium sulfide, chromium oxide, a sodium aluminum silicate complex, an ultramarine pigment, metal flakes, an azo pigment, a diazo pigment, phthalocyanine, a quinacridone pigment, a perylene pigment, isoindolinone, anthraquinone, thio-indigo, a solvent dye and combinations thereof .

There is thus provided according to another embodiment of the present invention, a method for forming a paint composition suitable for one-coat covering of a surface, the method including;

a. combining at least one inorganic particulate with water to form a mixture;

b. mixing the mixture with at least one paint to form a paint mixture; and

c. admixing the paint mixture with at least one of a sealer and a lacquer to form the paint composition . Additionally, according to an embodiment of the present invention, the combining step further includes warming the water to a temperature in the range of 20-50°C.

Furthermore, according to an embodiment of the present invention, the at least one inorganic particulate includes calcium carbonate and calcium sulfate.

Yet further, according to an embodiment of the present invention, the paint composition is a waterborne paint composition .

Moreover, according to an embodiment of the present invention, the paint composition is formed by a method disclosed herein.

Additionally, according to an embodiment of the present invention, the paint composition is stable for at least two months of storage. Furthermore, according to an embodiment of the present invention, the paint composition is stable for at least six months of storage. Further, according to an embodiment of the present invention, the paint composition covers a wooden surface adequately in a one-coat application step.

The present invention will be more fully understood from the following detailed description of the preferred embodiments thereof, taken together with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood. With specific reference now to the figures in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

In the drawings :

Fig. 1 is a simplified flow chart of a method for producing a paint composition, in accordance with an embodiment of the present invention;

Fig. 2A is an image of two wooden chairs before coating with the paint composition of the present invention;

Fig. 2B is an image of the two wooden chairs of Fig. 2A after coating with a paint composition, in accordance with an embodiment of the present invention;

Fig 3 shows an image of two glass jars, one uncoated and one coated with a paint composition, in accordance with an embodiment of the present invention;

Fig. 4. shows an image of plastic flower pots coated with a paint composition, in accordance with an embodiment of the present invention;

Fig. 5. shows an image of a metallic tin and lid coated with a paint composition, in accordance with an embodiment of the present invention;

Fig. 6A is an image of a wooden table before coating with the paint composition of the present invention; and

Fig. 6B is an image of the wooden table of Fig. 6A after coating with a paint composition, in accordance with an embodiment of the present invention.

In all the figures similar reference numerals identify similar parts.

DE TAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that these are specific embodiments and that the present invention may be practiced also in different ways that embody the characterizing features of the invention as described and claimed herein. Reference is now made to Fig. 1, which is a simplified flow chart 100 of a method for producing a paint composition, in accordance with an embodiment of the present invention. According to this embodiment, the production of the paint composition is performed in one vessel in batch mode. However, this should not be considered to be limiting and some/all of the steps may be performed in continuous, fed-batch, plug flow and other modes, as are well known in the art.

A vessel of a suitable size and geometry is chosen for the performance of all the steps. This may be a stainless steel cylindrical vessel with an optional external cooling jacket. At least one inorganic powder and water are placed in the vessel in a preparatory step 102 to form a mixture. According to some embodiments, the water may be heated to a temperature between 4-100°C, 10-90 °C, 20-80 °C, 30-70 °C, 35-50 °C, or 35 to 45 °C .

In one particular embodiment, the vessel temperature for the combining step should be maintained at 20-90°C, or more preferably at 30-45 °C . If required, external cooling may be used by means of cooling water in a cooling jacket, if required. Heating, however, is not mandatory in preparing the paint composition of the present invention. In fact, it has surprisingly been found, that vigorous admixing the particulate components of the composition in water medium compensates for elevated temperature. Surprisingly, the resulting admixture and finally dry layer of paint turn to be homogeneous and smooth. According to the above, and in one particular non- limiting embodiment, the paint composition is vigorously stirred at standard room temperature until a smooth mixture is obtained. The stirring may be done with any mechanical, electrical, magnetic or any other stirring means, which may be manual or automatic. Further, this procedure is less energy and time consuming, since no heating and following cooling steps are required.

In still another particular non-limiting embodiment, the paint composition is sifted through to screen out any still remaining particulates and obtain a smooth and homogeneous composition. The sifting step may be done at least once after admixing the paint composition and the sieve opening of the sifter mesh may be anywhere between 125 mm and 0.1 mm.

According to some embodiments the at least one inorganic powder comprises two inorganic powders. According to some embodiments, the at least one inorganic powder is in a weight ratio to water of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1. According to some embodiments, the two inorganic powders are in a weight ratio to water of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1.

According to some embodiments, the at least one inorganic powder comprises calcium carbonate.

According to some embodiments, the calcium carbonate is in a weight ratio to water of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1.

According to some embodiments, the second inorganic powder comprises calcium sulfate.

According to some embodiments, the calcium carbonate is non-hydrated . According to other embodiments, the calcium carbonate is hydrated. According to some embodiments, the calcium sulfate is in a weight ratio to water of 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2 or 9:1.

According to some embodiments, the calcium sulfate is non-hydrated. According to other embodiments, the calcium sulfate is hydrated.

According to some embodiments, the water may comprise additives .

According to some further embodiments, the water may be replaced with an aqueous solution. According to some further embodiments, the additives may be added to the mixture .

Thereafter, the mixture formed in step 102, is mixed with at least one paint, in the same or another vessel in a mixing step 104 to form a paint mixture. According to further embodiments, the inorganic powders comprise solid particles of an average diameter of 1-50 microns, or, according to further embodiments 5-25 microns. The weight ratio of the at least one inorganic powder to water is in the range of 4:1 to 1:4. The weight ratio of the paint composition to water is 4:1 to 1:4. According to some embodiments, the ratio is 4:1 to 2:1.

After step 104, the paint mixture is admixed with at least one sealer or lacquer in an ad-mixing step 106 to form a paint composition. According to some embodiments, the weight ratio of the sealer and or lacquer to water is 4:1 to 1:4.

According to some embodiments, the weight ratio of the sealer and or lacquer to the paint mixture is 4:1 to 1:4.

In an embodiment of the present invention, the additive is a pH adjusting agent or a buffering agent. Suitable buffering agents include but are not limited to acetic acid, adipic acid, calcium hydroxide, citric acid, glycine, hydrochloric acid, lactic acid, magnesium aluminometasilicates , phosphoric acid, sodium carbonate, sodium bicarbonate, sodium citrate, sodium hydroxide, sorbic acid, succinic acid, tartaric acid, and derivatives, salts and mixtures thereof.

In an embodiment of the present invention, the additive is a preservative. Suitable preservatives include but are not limited to C12 to C15 alkyl benzoates, alkyl p- hydroxybenzoates , aloe vera extract, ascorbic acid, benzalkonium chloride, benzoic acid, benzoic acid esters of C9 to C15 alcohols, butylated hydroxytoluene, castor oil, cetyl alcohols, chlorocresol , citric acid, cocoa butter, coconut oil, diazolidinyl urea, diisopropyl adipate, dimethyl polysiloxane, DMDM hydantoin, ethanol, fatty acids, fatty alcohols, hexadecyl alcohol, hydroxybenzoate esters, iodopropynyl butylcarbamate, isononyl iso-nonanoate, jojoba oil, lanolin oil, methylparaben, mineral oil, oleic acid, olive oil, polyethers, polyoxypropylene butyl ether, polyoxypropylene cetyl ether, potassium sorbate, silicone oils, sodium propionate, sodium benzoate, sodium bisulfite, sorbic acid, stearic fatty acid, vitamin E, vitamin E acetate and derivatives, esters, salts and mixtures thereof. After the mixing step, an ad-mixing step 106 is performed. In this ad-mixing step the paint mixture is mixed with at least one of a sealer and a lacquer to form said paint composition. Typically, the weight ratio of the paint mixture to sealer/lacquer is 4:1 to 1:4.

According to some embodiments of the present invention colored additives may be added during the mixing or ad-mixing step. These colored additives may comprise, on the one hand, traditional pigments and processing additives, and the carriers are made of natural "green" ingredients, having no volatile substances, which evaporate and would normally leave residues . According to some embodiments of the present invention, at least one salt may be added to form the paint composition, such as, but not limited to sodium chloride and potassium chloride .

According to another embodiment of the present invention a starch may be added to the paint mixture or paint composition. The starch can be used as an added assistance to control viscosity and stability.

A colorant additive may be added to the paint mixture or paint composition. The term "colorant" used throughout this specification and in the appended claims, to denote any conventional inorganic or organic pigment, organic dyestuff, or carbon black. Those skilled in the art will be aware of suitable inorganic pigments, organic pigments and dyestuffs useful in component (II) of the concentrate compositions. Such pigments are described, for example, in Kirk-Othmer Encyclopedia of Chemical Technology, Third Edition, vol. 6, pp. 597-617 which is incorporated by reference herein; examples are:

(1) inorganic pigments, such as titanium dioxide, carbon black, iron oxide, zinc chromate, cadmium sulfides, chromium oxides, sodium aluminum silicate complexes, such as ultramarine pigments, metal flakes and the like; and (2) organic types such as azo and diazo pigments, phthalocyanines , quinacridone pigments, perylene pigments, isoindolinone, anthraquinones , thioindigo, solvent dyes and the like. Although principally employed in the preparation of liquid colorant concentrates, the carrier (I) should also be suitable for the production of multi-functional dispersions that combine a colorant with one or more standard additives.

Further suitable additives for adding to the paint mixture or paint composition include, but are not limited to, UV stabilizers or absorbers, antioxidants, fire retardants, blowing agents, anti-stats, lubricants, impact modifiers, mold release agents, filler/reinforcing materials, or mixture of two or more of these ingredients. In this way, a single system can impart multiple functional properties to the thermoplastics treated. Hence, unless specifically excluded, when the term colorant is employed for the purpose of describing the concentrate of this invention, it contemplates also additives in general. The paint compositions of the present invention may be mixed by any suitable mixing means. For example, a particularly useful procedure is to mix the paint mixture with one or more additives using conventional mixing equipment such as a double ribbon blender, a drum tumbler or a planetary slow mixer, etc. The additives and powders may be mixed in the form of granules, pellets, and/or powder in a low shear mixer.

Additional additives to the paint mixtures and paint compositions of the present invention include polymeric resins, such as thermoplastic and thermoset resins. For example, the following resins: polyolefins such as LLDPE, HDPE, LDPE, homopolymer and copolymer polypropylenes , EVA, etc.; styrenics such as crystal polystyrene, HIPS, MIPS, etc.; copolymer resins, resin blends and alloys such as ABS, polyphenylene ether (including PPO blends such as NORYL®) , various engineering polymer alloys; polyamide resins, such as Nylon 6, 6/6, 11, 12, copolymers, terpolymers, etc.; acrylic resins, polycarbonates, and other amorphous resins; polyesters, such as PET, PBT, and others--both thermoplastic and curing, as well as resins reinforced with glass, quartz, carbon, Aramid, or the like, fibers.

Additional additives to the paint mixtures and paint compositions of the present invention include biodegradable plastics, which are plastics that will decompose in natural aerobic (composting) and anaerobic (landfill) environments. Materials such as a polyhydroxyalkanoate (PHA) biopolymer are completely compostable in an industrial compost facility. Polylactic acid (PLA) is another 100% compostable biopolymer which can fully degrade above 60C in an industrial composting facility. Fully biodegradable plastics are more expensive, partly because they are not widely enough produced to achieve large economies of scale. A "colloidal dispersion" is defined herein as a heterogeneous system which is made up of a dispersed phase and dispersion medium. In a colloidal dispersion, at least one substance is dispersed as very fine particles in another substance called a dispersion medium. A colloidal suspension is a colloidal dispersion in which the dispersed phase is solid and the dispersion medium is liquid .

It should be understood that the terms homogenizing, size-reducing, milling may be used interchangeably herein. It should be understood that the terms colorant, dye and pigment may be used interchangeably herein. Reference is now made to Fig. 2A, which is an image of two wooden chairs before coating with the paint composition of the present invention. The chairs are vintage chairs, but have a used appearance. Fig. 2B is an image of the two wooden chairs of Fig. 2A after coating with a paint composition, in accordance with an embodiment of the present invention. As can be seen in Fig. 2B, the painted chairs look much newer than the unpainted chairs.

Fig 3 shows an image of two glass jars, one uncoated and one coated with a paint composition, in accordance with an embodiment of the present invention. The paint composition of the present invention is well adapted to application on a glass object, as can be seen in the figure.

Fig. 4 shows an image of plastic flower pots coated with a paint composition, in accordance with an embodiment of the present invention. The paint composition of the present invention is well adapted to application on a plastic object, as can be seen in the figure.

Fig. 5 shows an image of a metallic tin and lid coated with a paint composition, in accordance with an embodiment of the present invention. The paint composition of the present invention is well adapted to application on a metallic object, as can be seen in the figure.

Reference is now made to Fig. 6A, which is an image of a wooden table before coating with the paint composition of the present invention.

Fig. 6B is an image of the wooden table of Fig. 6A after coating with a paint composition, in accordance with an embodiment of the present invention. The paint composition of the present invention is well adapted to application on a wooden object, as can be seen in the figure. As can be seen in Fig. 6B, the painted table looks much better finished than the unpainted table.

EXAMPLES

Example 1 Formation of a Paint Composition

16 grams CaCC>3, 16 grams CaSC^ and 40 ml of water are mixed at 35-40°C to form a mixture. The mixture is mixed with 100 mL of paint to form a few minutes with a mechanical mixer to form a paint mixture. Thereafter, the paint mixture is mixed with 40 mL of sealer to form the paint composition.

The paint composition formed is temperature stable and can be stored in closed containers in a temperature range of - 22°C to + 30 °C . Some of the paint formulations and compositions of the present invention are stable in closed containers in a temperature range of -10°C to + 80 °C .

The paint composition of the present invention can be stored for more than two months, more than six months or more than a year, and be used thereafter after a short mixing process .

Moreover, objects coated with the paint composition can be stored in a temperature range of -22°C to + 30 °C for long periods of time without the coat/paint peeling therefrom. The period of time can be more than two months, more than six months or more than a year.

Example 2 Formulation of Exterior/Interior General- Purpose Waterborne Coating

The following tables detail the two parts of paint composition that can be used in single coating on any type of surface without pre-treatment or post-sealing actions according to the present invention. The two parts and components thereof are compatible with each other when admixed together before coating, forming a homogeneous mixture. Part A is the basic paint composition that provides the foundation of the paint composition. The composition in Part A is divided in two basic sets of components: Pigment Grind that contains pigment particulates and supporting particulates that help disperse the pigments in the water medium and stabilize a homogeneous dispersion. The second set of components is termed LET-DOWN and contains the matrix forming components that lock the particulates in the first set in after the paint is dry. The major components in the second LET-DOWN set are mostly polymer resins, particularly acrylic resins may be used, and also film formers and defoamers that help maintain a uniform bubble free layer. Preservatives such as biocides may be introduced to prevent deterioration of the paint layer during use and ensure its longevity. Part B is essentially introduced into the medium formed by Part A. Part B contains the components that provide the required protection for the foundation paint, enhancing the durability of the paint layer.

Part A: Composition of Basic Pai

Acrylic resin Binder 350

Colloid 643 Defoamer 1.5

Nucide 404-D Biocide 5

Coalescent (e.g. Film former 9

Texanol )

Water Diluent 230

Part B: ERIKA - Paint Compound

One should note that the paint admixture in the present invention can be prepared in any suitable temperature and mixing intensity. In fact and in one particular non-limiting embodiment, Part B, that is the paint compound above, is admixed with Part A, the basic paint, at standard room temperature, without any heating or preheating of either part. The two parts are vigorously stirred together with any mechanical, electrical, magnetic or any other stirring means, which may be manual or automatic until a smooth mixture is obtained. This way crystallization of the paint and basic paint particulates is prevented despite the elimination of the heating factor. Further, it has also been surprisingly discovered that such procedure of preparing the paint admixture leads to a smooth dry layer . Non-limiting examples of paints, sealers and lacquers are provided hereinbelow.

One paint comprises naphtha in a concentration of 10-75%, titanium dioxide 10-25% and various additives.

Another paint comprises 10-30% water, 15-30% calcium carbonate, 20-30% acrylic emulsion, 15-25% titanium dioxide, 3-6% mica and 3-6% silica Kaolin. This paint may optionally comprise suitable additives.

According to some embodiments, the paint is waterborne. According to some embodiments, the sealer comprises 70-9-

% self-cross-linking acrylic polymer and additives.

According to other embodiments, the sealer is a commercial clear thermosetting sealer, based on a resin.

According to other embodiments, the lacquer is a clear coating formulation comprising 40-50% acrylic polymer and 25- 35% polyurethane polymer.

According to other embodiments, the lacquer is a high performance water-borne air dry coating comprising 70-80% resin, such as epoxy polyamide, at least one drying agent and bulking agents.

While the invention has been explained in relation to its preferred embodiments, 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. The references cited herein teach many principles that are applicable to the present invention. Therefore the full contents of these publications are incorporated by reference herein where appropriate for teachings of additional or alternative details, features and/or technical background.

It is to be understood that the invention is not limited in its application to the details set forth in the description contained herein or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will readily appreciate that various modifications and changes can be applied to the embodiments of the invention as hereinbefore described without departing from its scope, defined in and by the appended claims.