DESC:Field of the Invention
The present invention relates to coatingformulations/systempreferably interior wall coating formulations comprisingco-acting blend/synergistic combination of acrylic copolymer emulsion of Tg range spanning -45 to +25 deg C (including high and low Tg polymers by optionally involving styrene as monomer) free of any hydroxyl value, aliphatic polyester polycarbonate based anionic polyurethane dispersion inparaffin/silicon wax emulsion enabling superior scrub resistance, scuff resistance (R=94 out of 100), Stain resistance (Rating 147 out of 150) and dirt pick up resistance (DPUR) (R=9 out of 10) along with crack bridging ability (up to 0.5 mm), and superior block resistance (R=9 out of 10), also adapted for dead matt finish (less than <7 @85 G.H) when present together with matting emulsion.

Background of the Invention
In past few decades, considerable efforts have been devoted by various industries to develop high performance waterborne paints for interior wall application.
The interior walls with high traffic areas or narrow space between the walls, such as dressing room, kitchen or passage are more prone for often rubbing by people or objects such as cloth, shoes, or furniture during day-to-day activities. Generally, these objects leave scuff marks on the wall either by making scratch or removal of superficial paint layer or create burnishing marks. Removing these scuff marks is a challenge. In addition removal of various stains such as sauces, pickles, beverages, oils, turmeric, shoe polish, ink marks etc. is also a great challenge and require cleaning which might damage the painted surfaces and incurs extra expenditure.
References of the related prior arts are invited as follows:
US8980995 discloses latex paint having excellent water resistance, color rub-off scrub resistance. This performance is achieved by using wax additives which is entrapped in the polymer matrix by making hybrid emulsion (not just on the surface of the matrix polymers).

WO2019/160681A1 is related to paints having excellent stain resistance and scuff resistance. This advancement teaches paint composition made by using seeded emulsion blended in film forming latex along with opacifying pigments. It is also disclosed that latex may be silicon modified alkyd emulsion, low molecular wt. polyethylene wax, or Low molecular weight polyolefin paraffin wax or Hybrid.

US7834086B2 relates to coating compositions that include a multistage latex polymer backbone with a silane coupling agent. The latex polymer preferably comprises acetoacetoxy functionality. This prior art also discloses that polymer backbone comprises at least one soft stage having a Tg between about -65 and 30 deg C. and at least one hard stage having a Tg between about 30 and 23.0 deg. It was highlighted that crosslinking was achieved by addition of AAEM (Acetoactoxy ethyl methacrylate).

US2004/0242765A1 reveals aqueous polyurethane dispersion with soft effects. The tactility of soft feel effects (a particular tactual sensation-tactility) of the coated surface can be described using terms such as velvety, soft, rubberlike, warm whereas, for example, the surface of a painted car body or else an unpainted polymer sheet or one coated with a customary clear coat or topcoat material and made by using polycarbonate from Bayer AG. This composition consists of one or more polyhydroxyl compounds having a number-average molecular weight (M)2500 daltons and an average OH functionality of 21.5 and at least one cross linker.

US7166236B2 relates to compositions and methods to impart strong stain resistance to polyamide textile substrate (Nylon). This coating imparts excellent clean ability of coffee and/or acid dyes to a polyamide substrate. The advancementcomprises: a crosslinking agent such as hydroxyl terminated polybutadiene grafted with maleic anhydride.

US2017/0327109A1teaches for dirt pick up resistance (DPUR) composition. The disclosed composition is made by water dispersible polymer, UV absorber and sealant. The coating shows DPUR along with UV absorbent and sealant properties. The DPUR performance is achieved by addition of external crosslinking agent AAEM (acetoacetoxy ethyl methacrylate) OR DAAM (diacetone acrylamide) in proportion of 1 % to 5% on wt. basis.

US5578669 discloses waterborne coating for surface treatment for metal substrate or other architectural substrate and reveals that coating compositions using waterborne polymer results in coated substrates showing excellent water resistance, corrosion resistance performance with high degree of hardening.

US5959020 provides UV curable composition containing at least one wax molecule with combination of radiation polymerizable compound. This coating is applicable for various kind of substrate.

US7396875B2 reveals UV-curable waterborne polyurethane dispersions for soft touch coatings. The emulsion is prepared by a) reacting specified hydroxy-functional components with di- and/or polyisocyanates, b) forming a dispersion of the resultant product with water and reacting the dispersion with amine functional materials. However this advancement provides no information about the performance parameters like hardness, sheen or scuff resistance (specially designed for soft feel)

US5962573 relates to directly paintable thermoplastic olefin composition. The composition contains oxidized polyethylene wax and is particularly useful for making injection molding automotive parts.

EP1877452B1discloses the composition of solvent based coating which can be used as primer or top coat or clear coat for fast curable and durable films. It is also disclosed that the binder is hydroxy functional acrylic backbone and in one embodiments OH functional acrylic is cured with amine functional silicon resulting in superhydrophobic coating with durability.

EP2791257B1 relates to polymer dispersion having anti-fog performance. This coating consists of two segments - one is polyurethane segment and other is acrylic segments.

KR 2294159 B1discloses a water-soluble nonflammable coating compounds, comprising 25-30% of polyester polyol resin, 20-25% of polycarbonate polyurethane dispersion, 15-20% of acrylate resin, acrylic/styrene copolymer emulsion resin 5- 10%, silica aerogel, 2-sodium propenoate 2-propenamide polymer, flame retardant, mixed water and additives. It not only reduces indoor environmental pollutants, but also has non-combustible property, durability, impact resistance, adhesion to the surface to be coated, antibacterial property and deodorization property.

US4263355relates to paint shield (films) for making edges of floor carpets. This films show excellent water resistance and stain resistance performance.

CN110317301A teaches about an emulsion which is manufactured, from hyper branched polyester-modified polyurethane aqueous dispersion as core structure, acrylate (Me acrylate, etc.) pre-emulsified monomer mixture as shell structure, and aq. initiator (persulfate) for initiating the crosslinking reaction between the shell and the core structure; wherein, the hyperbranched polyester-modified polyurethane is manufactured from multifunctional isocyanate (aliphatic/alicyclic) and polymer polyol (polyester polyol, polyether polyol, and polycarbonate polyol), and carboxy-containing hyper branched polyester. Discloses the preparation method of the title emulsion. This prior emulsion is used as coating material.

EP2277961A1 relates to new composition combining an acrylic component with another PU component and their uses for liquid membrane for roofs (special for outdoor application). This coating shows excellent crack bridging ability.

JP2011207945Aconcerns about an aqueous coating, containing urethane resin dispersions with av. diam. (f) 15-100 nm, acrylic emulsions with Tg =60° and f 50-200 nm, water, colorants, and solvents R1O(CH2CHR2O)nH (R1 = C1-6 alkyl; R2 = H, Me; n = 1-3) shows excellent storage stability and wettability to a vinyl chloride resin, PET, and a metal substrate, respectively.

JP2006009019A provides a coating composition comprising a polyurethane dispersion which has a carboxylate functional value at an improved level and gives coating films having good film hardness, flexibility, water resistance and abrasion resistance and excellent solvent resistance, when cross-linked with a proper cross-linking agent. The prior art is more about the synthesis of Polyurethane dispersion polymer by two step process. (a) acid terminated polyester backbone (b) in second stage condensation of acid terminated backbone with acrylic polyols and subsequently make waterborne dispersion.

US5962573 teaches addition of oxidized polyethylene waxes to a thermoplastic polyolefin composition which resulted improved adhesion to paints.

WO2018114838relates to an aqueous dispersion of polyurethane and a method for preparing the same, use thereof in a coating composition, and a coated product. The aqueous dispersion of polyurethane according to the advancement is well dispersed, and is capable of forming a coat with good waterproof, moisture permeability and washing resistance. However the advancement do not talk about the other important performance properties like sheen, scuff resistance, stain resistance and block resistance etc.

US7291676discloses adding specific oxidized polyethylene waxes polyolefin to achieve a good balance between abrasion resistance and softness for the molded parts.

Traversal of the prior arts indicate that conventional interior wall paints/coating systems are formulated by using acrylic or styrene acrylic binder which displays very obvious properties like water resistance, alkali resistance, film hardness with average stain cleanability. The drawbacks of theseacrylic base emulsioncompositions is that they have limited performance score for scuff resistance, stain resistance, crack bridging ability, and DPUR (dirt pick up resistance).

Technically thus it is a challenge in the art to bring two contradictory properties like stain resistance, block resistance and DPUR which are obtained by hard polymer film, and other properties like crack bridging ability which is due to the elasticity of the polymer film and to attain such properties from the same coating formulationthat too by involving non-reactive co-acting blend of emulsions that arenon-condensable is thus a challenge to circumvent, to which the present invention is thus directed to bring about such change in paints and coating suitable for interior wall applications. To have a matting finish out of such coating systems is yet another challenge to circumvent.

Objective of the Invention
Thus, the primary objective of the present invention is to provide for a coating system/formulationcomprising co-acting combination of dispersion/ emulsionswhich would enable attaining two contradictory properties like stain resistance, block resistance, DPUR and other properties like crack bridging ability together in the cured film that would also be adapted to deliver matt finish.

Another objective of the present invention is to provide for said coating system/formulation based on hybrid chemistry of high/low glass transition temperature based acrylic emulsion free of any hydroxyl value together in combination withanionic polycarbonate polyurethane dispersion at a select ratioto provide for said contradictory properties by the formulation fostered by seededsilicon/paraffin wax emulsion present in the formulation.

Another objective of the present invention is to provide for said coating/paint formulation/ composition which would have high performance score for scuff resistance, stain resistance, crack bridging ability and DPUR.

Yet another objective of the present invention is to provide for said paint formulation/composition which would perform as high performance waterborne architectural paint or deliver high performance matt finish.
Another objective of the present invention is to provide said paint formulation/composition which would also possess excellent stability without phase separation even after 5 cycles in freeze-thaw stability, and accelerated stability tests.
Yet another objective of the present invention is to provide for said paint formulation/ composition which would provide films having excellent stain clean ability including stains from pencil, oil crayon, wax crayon, sketch pen, highlighter, white board marker, lipstick, shoe polish wax, show polish liquid, turmeric pickle, soya sauce, tomato sauce.

Summary of the Invention
In the primary embodiment the present invention is directed to provide a polyurethane-acrylic hybrid coating system comprising
(a)22 to 88 wt.% acrylic copolymer emulsion having Tg ranging from 25 deg C to -45 deg C;
(b)2 to 10 wt.% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C;
(c) 1 % to 4 wt. % wax dispersion;
as a synergistically co-acting combination in said coating system adapted for contradictory attributes of significant stain resistance, scuff resistance, DPUR, with significant crack bridging ability out of single coating system.
Another embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system wherein said acrylic copolymer emulsion is a copolymer of acrylate and methacrylate monomers optionally involving styrene monomer (5-15 Wt%) of 48-52% solid content free of any hydroxyl valuefor inclusion in said coating system that is selectively surfactant stabilized based on select combination of non-ionic alcohol ethoxylates and anionic surfactant including polycarboxylic acid salts having particle size distribution of 100-500 nm at pH range of 7.5 to 9.5 for desired interlinking and coalescing of the latex particles with said anionic polycarbonate polyurethane dispersion of select particle size ranging from 100 nm to 300 nm having pH in the range of 7.5 to 8.5 and wax dispersion to result in cohesive and ductile film resulting in suitable scuff resistance attributes.
Yet another embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system wherein said wax dispersion includes paraffin wax dispersion having wax content 10-30 % with 1 to 5 % C9 to C-11 & C16-18 Alcohols having 1 to 5% ethoxylated content; and said anionic polycarbonate polyurethane dispersion of 33-37% solid contentis solvent free aliphatic, polyester-polycarbonate based anionic polyurethane dispersion of said pH in the range of 7.5 to 9.5 and particle size distribution of100-300 nm.
Another embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system wherein said ratio of styrene-acrylic copolymer emulsion: anionic polycarbonate polyurethane dispersion: wax dispersion is in the ratio range of 81-91:5-15:1-9 to enable desired attributes.
Further embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating systemas self-curing room temperature curable non-reactive/non-condensable blend of said polymeric dispersions/emulsion.
Still further embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system includes coating ingredients of thickeners, defoamers, glycols including mono or di or polyfunctional glycols, aqueous solution of 2-amino-2-methyl-1-propanol as neutralizer amine, pigments including opacifying pigment Titanium dioxide along with extender including Kaolin 20 to 40 wt.% having solvent in the levels of only <50 g/Lit and thereby is water borne coating system having excellent freeze-thaw stability without phase separation even after 5 cycles in relation to accelerated stability tests of being stable at hot condition of 55 Deg C for 30 days and stable at cold condition of -5 Deg C for 15 days, and is adapted for a cured coating film with a gloss value 45-60 unit @60 gloss head.
Further embodiment of the present invention is directed to provide saidpolyurethane-acrylic hybrid coating systemcurable at ambient temperature suitable for luxury category finishes exhibiting high gloss (45-60 unit @60 gloss head), scuff resistance(94 score out of 100), stain resistance (147 score out of 150), crack bridging ability (0.5 mm), Block resistance (rating 9 out of 10), very high dirt pick up resistance (DPUR) (R=9 out of 10), excellent stain clean ability along with excellent scrub resistance (500-1000 cycle as per the ASTM D4213).
Another preferred embodiment of the present invention is directed to provide a method of manufacturing polyurethane-acrylic hybrid coating system comprising
(a) providing said 22 to 88 wt% acrylic copolymer emulsion having Tg ranging from 25 deg C to -45 deg C,
(b) providing said 2 to 10 wt% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C
(c) providing said 1 to 4 wt.% wax dispersion for blending with said (a) and (b) preferably enabling a ratio range for components a:b:c of 81-91:5-15:1-9 to obtain therefrom said polyurethane-acrylic hybrid coating system.
Another embodiment of the present invention is directed to provide said method of manufacturing of polyurethane-acrylic hybrid coating systemwherein said coating system for inclusion of (a)-(c) above is first prepared by the following steps of
(i) Providing Water, Glycols including mono or di or polyfunctional glycols, aq. solution of 2-amino-2-methyl-1-propanol as a neutralizer, Foam control agent, antifungal agent/biocide, in-can preservative, defoamer together with surfactant and wetting agents;
(ii) Adding thickener including non-ionic synthetic associative thickener under slow speed stirring at RPM 400-600, white pigment including titanium dioxide at RPM 1200-1500 for 10 minutes followed by addition of extenders and evaluating the finish on panel at an interval of 10 minutes to ensure lump free dispersion;
(iii) Adding further Coalescing agent, Flow and levelling agents in said lump free dispersion followed by addition of styrene-acrylic emulsion that is stabilized by surfactants and anionic Polycarbonate polyurethane waterborne dispersion and continued stirring at 700 RPM for 10 minutes.
(iv) adding water, wax dispersion and additives including fluro additives with continued stirring at 700 RPM for 10 minutes to provide said polyurethane-acrylic hybridcoating systemhaving viscosity in the range of 90-110 KU Stormer viscometer at 30 °C and solid content by weight (%): 45 ± 1.5 at 120°C for 1 hour.
Another preferred embodiment of the present invention is directed to provide apolyurethane-acrylic hybrid coating system comprising
(a) 11 to 77 wt.% acrylic copolymer emulsion having Tg ranging from -45 deg C to 5 deg C;
(b) 2 to 10 wt.% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C;
(c) 1 % to 4 wt.% wax emulsion;
(d) 10% to 22wt.% matting emulsion having Tg range of -45 to 5 deg C and viscosity 500 to 1500 cps;
as a synergistically co-acting combination in said coating system adapted for contradictory attributes of significant stain resistance, scuff resistance, DPUR, with significant crack bridging ability out of single coating system advantageously adapted for matt finish.
Another embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system wherein said acrylic copolymer emulsion: polycarbonate PUD: wax emulsion preferably silicone wax emulsion: matting emulsion is in the ratio of (70-80:7:3:10-20)to enable desired attributes.
Further embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system wherein said acrylic copolymer emulsion is a copolymer of acrylate and methacrylate monomers optionally including styrene monomer (5-15%) of 48-52% solid content free of any hydroxyl valuefor inclusion in said coating system that is selectively surfactant stabilized based on select combination of non-ionic alcohol ethoxylates and anionic surfactant including polycarboxylic acid salts having particle size distribution of 100-500 nm at pH range of 7.5 to 9.5 for desired interlinking and coalescing of the latex particles with said anionic polycarbonate polyurethane dispersion of select particle size ranging from 100 nm to 300 nm having pH in the range of 7.5 to 8.5 and wax emulsionto result in cohesive and ductile film resulting in suitable scuff resistance attributes.
Still further embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system wherein said wax emulsion is a silicone wax emulsion including polysiloxanesand said anionic polycarbonate polyurethane dispersion of 33-37% solid contentis solvent free aliphatic, polyester-polycarbonate based anionic polyurethane dispersion of said pH in the range of 7.5 to 9.5 and particle size distribution of100-300 nm.
Another embodiment of the present invention is directed to provide saidpolyurethane-acrylic hybrid coating systemas self-curing room temperature curable non-reactive/non-condensable blend of said polymeric dispersions/emulsion.
Yet further embodiment of the present invention is directed to provide said polyurethane-acrylic hybrid coating system includes coating ingredients of thickeners, defoamers, Glycols including mono or di or polyfunctional glycols, aqueous solution of 2-amino-2-methyl-1-propanol as neutralizer amine, pigments including opacifying pigment Titanium dioxide along with extender including Kaolin 20 to 40 wt.% having solvent in the levels of only <50 g/Lit and thereby is water borne coating system having excellent freeze-thaw stability without phase separation even after 5 cycles in relation to accelerated stability tests of being stable at hot condition of 55 Deg C for 30 days and stable at cold condition of -5 Deg C for 15 days, and is adapted for a cured coating film with a dead matt finish of less than <7 @85 gloss head.
Another embodiment of the present invention is directed to provide saidpolyurethane-acrylic hybrid coating systemcurable at ambient temperature suitable for luxury category finishes exhibiting dead matt finish of less than <7 @85 gloss head, scuff resistance(94 score out of 100), stain resistance (147 score out of 150), crack bridging ability (0.5 mm), Block resistance (rating 9 out of 10), very high dirt pick up resistance (DPUR) (R=9 out of 10), excellent stain clean ability along with excellent scrub resistance (500-1000 cycle as per the ASTM D4213).
Another preferred embodiment of the present invention is directed to provide a method of manufacturing Polyurethane-acrylic hybrid coating system comprising
(a) providing said 11 to 77 wt.% acrylic copolymer emulsion having high Tg ranging from -45 deg C to 5 deg C;
(b) providing said 2 to 10 wt.% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C;
(c) providing said 1 % to 4 wt.% wax emulsion;
(d) providing said 10% to 22wt.% matting emulsion having viscosity 500 to 1500 cps; for blending preferably in the ratio range of components a:b:c:d of 70-80:7:3:20-10 to obtain therefrom said polyurethane-acrylic hybrid coating system.

Another embodiment of the present invention is directed to provide said method of manufacturing of Polyurethane-acrylic hybrid coating systemwherein said coating system for inclusion of (a)-(d) above is first prepared by the following steps of
(i) Providing water, Glycols including mono or di or polyfunctional glycols, aq. solution of 2-amino-2-methyl-1-propanol as a neutralizer, Foam control agent, Antifungal agent/biocide, in-can preservative, defoamer together with surfactant and wetting agents;
(ii) Adding thickener including non-ionic synthetic associative thickener under slow speed stirring at RPM 400-600, white pigment including titanium dioxide at RPM 1200-1500 for 10 minutes followed by addition of extenders and evaluating the finish on panel at an interval of 10 minutes to ensure lump free dispersion;
(iii) Adding further coalescing agent, flow and leveling agents in said lump free dispersion followed by addition of acrylic copolymer emulsion that is stabilized by surfactants and anionic polycarbonate polyurethane waterborne dispersion and continued stirring at 700 RPM for 10 minutes.
(iv) adding water, wax emulsion preferably silicone wax emulsion and additives including fluro additives with continued stirring at 700 RPM for 10 minutes to provide said polyurethane-acrylic hybridcoating systemhaving viscosity in the range of 90-110 KU Stormer viscometer at 30 °C and solid content by weight (%): 45 ± 1.5 at 120°C for 1 hour.

Detailed Description of the Invention
As discussed hereinbefore, the present invention provides for a coating/paint system/ formulation comprising a synergistic co-acting combination of acrylic co-polymer of Tg range of from -45 to +25 deg C (including high and low Tg polymers optionally involving styrene as monomer) free of any hydroxyl value,aliphatic polyester polycarbonate based anionic polyurethane dispersion in silicon/paraffin wax as emulsion that are non-reactive and hence non-condensable with each other and allows attainment of advantageous characteristic attributes that conventional acrylic paints do not address such as the challenge of bringing two contradictory properties like stain resistance, block resistance, DPUR and other properties like crack bridging ability together, and thus have limited performance score for scuff resistance, stain resistance, crack bridging ability, and DPUR. These limitations of conventional coating formulation/ composition could be circumvented by the present coating system/ formulation/ composition with high performance rating for interior wall coating and are also well adaptable to dead matt finish.
Advantageously, the present coating system/ formulation also possesses excellent stability without phase separation even after 5 cycles in freeze-thaw stability, and accelerated stability tests.The synergistic paint/coatingformulation of the present invention displays excellent scuff resistance, stain resistance and crack bridging ability based on unique chemistry of anionic polycarbonate polyurethane dispersion in combination with (high/low) Tg acrylic emulsion as a hybrid combinationpresent in and aided by silicon/paraffin wax emulsion said hybrid combination seeded into said wax emulsion. Said wax dispersion is a functional ingredientin combination which gives best stain repellency.Thesaid synergistic coating formulation is an architectural aqueous coating formulationwhich could be further adapted to dead matt finishcomprising select combination of high/low Tg acrylic emulsion free of any hydroxyl value, anionically stabilized polycarbonate polyurethane dispersion in required quantity of paraffin/silicon wax dispersion/emulsion together with acrylic matting emulsion.
Paraffin/silicone wax dispersions/emulsions are stable mixtures of one or more waxes in water. Waxes and water are normally immiscible but can be brought together stably using surfactants and aselect preparation process. The most important properties that can be improved by the addition of wax emulsions are matting & gloss, hydrophobicity, soft touch, abrasion & rub resistance, scratch resistance, release, corrosion protection and anti-blocking.As mentioned above quantity of paraffin/silicon wax dispersion is very important to attain the desired characteristics of the coating formulation/system of the present invention. For more than 4% paraffin wax dispersion (5%) w.r.t. binder, the scrub resistance and scuff resistance became limited to 200-250 value and 80 respectively wherein paraffin wax dispersion less than 1% w.r.t. binder in the formulation showed very poor stain resistance value of 114 and inferior block resistance value of 5 out of 10 respectively.

Generally, from thermodynamic point of view dispersions are unstable, however, they can be made kinetically stable over a large period of time, which determines their shelf life. The formulation of the present invention showsexcellent stability without phase separation even after 5 cycles in freeze-thaw stability, and accelerated stability tests (stable at hot condition 55 Deg C for 30 days and cold condition -5 Deg C for 15 days).

The present invention in another embodiment, relates to said architectural aqueous coating composition that forms paint films having significant scuff (mark surface by rubbing it against something rough) resistance. Mainly incorporation of polycarbonate polyurethane dispersion in a select ratio with respect to high Tg acrylates in the formulation is responsible to achieve significant scuff resistance. The cured films show excellent scuff resistance e.g. rubs on various kind of objects such as Neoprene rubber, synthetic leather, natural leather, canvas cloth, painted wood, sunmica, jute, ink paper etc.

In yet another embodiment of the present invention said formulation providesnot only a cured rigid filmthat has excellent stain clean ability (stain like pencil, oil crayon, wax crayon, sketch pen, highlighter, white board marker, lipstick, shoe polish wax, show polish Liquid, turmeric pickle, soya sauce, tomato sauce, etc.)but also said cured film resulted in excellent scrub resistance (500-1000 cycle as per the ASTM D 3719). Thus present formulation makes paint films more rigid and ductile and significantly improves scrub resistance by 30-35 % wherein this improved scrub resistance is also consistent in tintable bases.

Dirt-pickup resistance (DPUR) is typically defined as the ability of a coating to resist dirt, which over the course of time, darkens the film and can result in an uneven appearance. Dirt pickup resistance (DPUR) is an important performance attribute for architectural coatings, especially in the places having very high vehicle load and high population that have poor air quality. In one embodiment the invented composition demonstrates very high dirt pick up resistance (DPUR) (R=9 out of 10) when cured as a film.

In another embodiment the invented formulation demonstrates the crack bridging ability up to 0.5 mm when applied in a complete system. Also, the crack bridging ability characteristic is consistence at severe environmental conditions.Generally, for cured paint films from acrylic based composition, the challenge is to achieve two contradictory performance properties such as crack bridging ability (CBA) along with scuff and stain resistance together. The present invention reveals that the unique proportion/ratio/composition surprisingly demonstrates excellent crack bridging properties (0.5 mm CBA) along with significant scuff and stain resistance.

In all embodiments, the wax dispersion includespolycarbonate polyurethane latex with particle size of 100-300 nm blended with acrylic latexes having average particle size of 100-500 nm which helps in interlinking and coalescing the latex particles, and results incohesive and ductile film which is responsible for scuff resistance properties.In films formation mechanism as the paint films curing occurs /filmdries water get evaporated and coalescing mechanism takes place and smaller particle of polycarbonate polyurethane latexhaving particle size (100-300 nm) take the spaces voids in between the particles of acrylic latex (having size 100-500 nm).This results in to coherent films formation and also responsible for stable dispersion, which otherwise becomes unstable.

In another embodiment of the present invention the said coating formulation can be classified as High performance products in Luxury category of finishes for the Interior wall decoration. The cured film exhibits high gloss (45-60 unit @60 gloss head), scuff resistance (94 score out of 100), stain resistance (147 score out of 150), crack bridging ability (0.5 mm), Block resistance (rating 9 out of 10). The formulation can very well be used for high traffic interior area like sports complex, kitchen, offices etc. and as self-priming with 2 coat of application for High gloss category.

Example-1
The present invention relates to coating formulation preferably ambient cure aqueous paint film made by hybrid polymer dispersion comprising unique combination of high/low glass transition temperature based acrylic copolymer emulsion optionally involving styrene monomer,with polycarbonate polyurethane anionic dispersion, paraffin wax dispersion/silicone wax emulsion, opacifying pigments and extender and providesHigh performance products in Luxury category of finishes for the Interior wall decoration.
Thus, thepreferably ambient cure aqueous hybrid polymer coating system comprisesa synergistic blend of
(a)surfactant stabilizedacrylic copolymer optionally including styrene monomer [for surfactant stabilization the ratio of non ionic: anionic surfactant is 1:1 based on a selective combination of nonionic (alcohol ethoxylate)as well as anioinic surfactant like polycarboxylic acid salts]having Tg ranging from 25 deg C to -45 deg C, pH 7.5 to 9.5and particle size distribution of 100-500 nm;
(b)polycarbonate polyurethane dispersion having Tg -50 to -10 deg C, pH 7.5 to 9.5 and particle size distribution having 100-300 nmthat is solvent free aliphatic, polyester-polycarbonate based anionic polyurethane dispersion having viscosity= 1,000 at 23 °C;
(c)paraffin wax dispersion 1 %to 4%;
together with opacifying pigment Titanium dioxide along with extenders including Kaolin,calcium carbonate, talcbased extender;organic solventincluding glycols and C12 to C16 long chain solvents<50 g/Litproviding gloss value 45-60 unit at 60 degree gloss ahead.
Neutralizer amine including 2-amino-2-methyl-1-propanol in aqueous solution is usedto maintain pH of the system in the range of 8 to 9.5,within this pH range the coating/ paint formulations are stable.
The anionically stabilized solvent free polycarbonate polyurethane was purchased from supplier for blending in select levels with selectively surfactant stabilized acrylic copolymer, and unless the acrylic copolymer is surfactant stabilized in the coating system does not generate the attributes of said coating system when pigmented, and hence involves controls at various levels.
The coating system thus includes the acrylic copolymer optionally including styrene as monomer further effectively stabilized in a pigmented coating system by involving non-ionic (alcohol ethoxylate) as well as anioinic surfactant including polycarboxylic acid salts in combination 0.55-2.25 wt % (Table-1)and as covered under the examples under Table 1 below.
Table-1 exemplifiesthe ingredients and respective quantities for the preparation of pigmented system based on hybrid polymer of acrylic copolymer (optionally including styrene as monomer) emulsion and polycarbonate polyurethane dispersion and wax dispersion present in the backbone of the coating system:
Table 1:Formulation ofpolyurethane-acrylic hybrid coating system for interior wall coating.
Sr.No Ingredients %PBW
1 WATER 5.74-22.5
2 Glycols(mono or di or polyfunctional glycols) 1.5-6
3 Neutralizer 2-amino-2-methyl-1-propanol in an aqueous solution 0.025-1
4 Foam control agent 0.07-0.3
5 Antifungal agent/biocide 0.3-1.5
6 In can preservative 0.05-0.2
7 defoamer 0.2-0.8
8 Surfactant and Wetting Agent 0.55-2.25
9 Thickener (non-ionic synthetic associative thickener) 0.5-2
10 White pigments(Titanium dioxide) 12-48
11 extenders 2.5-10
12 Coalescing agent 1.5-6
13 Flow and leveling agent 0.1-0.4
14 Acrylic copolymer (optionally including styrene as monomer 5-15%) emulsion 22-88
15 Polycarbonate polyurethane waterborne dispersion 2-10
16 Wax dispersion 1-4
17 Fluroadditives/ Fluro polymer 0.01-0.068

In Table 1above, the ratio (% solid basis) of acrylic emulsion(optionally including styrene as monomer 5-15%) is48-52% solid content by weight, and polycarbonate polyurethane dispersion is 33-37% solid content by weight.The above compositions were prepared using High Speed Mixer (HSM) with variable RPM.
Ingredients 1 to 8of water, glycols(mono- or di- or polyfunctional glycols), Neutralizer 2-amino-2-methyl-1-propanol in aqueous solution, foam control agent, antifungal agent/biocide, in can preservative, defoamer and surfactant and wetting agents) were first added in a cleaned stainless-steel container.
Under slow speed stirring at RPM 400-600, ingredient No 9(Thickener-non-ionic synthetic associative thickener) is added to increase the viscosity. Ingredients no 10 [white pigment (titanium dioxide)]is then added for 10 minutes at RPM 1200-1500 followed by addition of ingredient No-11extenders. To ensure lump free dispersion the finish is checked on panel at an interval of 10 minutes.
Ingredient no-12 and 13 (Coalescing agent, flow and levelling agent) are added in said lump free dispersion (the formulation mixture) followed by addition of ingredients 14 & 15 (acrylic copolymer emulsion and polycarbonate polyurethane waterborne dispersion) to the container and continued stirring at 700 RPM for 10 minutes. Next water, wax dispersion and fluro additivesare also added in the container and stirring continued at 700 RPM for 10 minutes. Viscosity of the sample/batch is found to be in the range of 90-110 KU Stormer viscometer at 30 °C and solid content by weight (%): 45 ± 1.5 at 120°C for 1 hour.
Foam control agent/defoamer is selected from Blends of Minerals oil and silica containing agents, antifungal agent/biocide is selected from component containing Zinc, defoamer is selected from Blends of Minerals oil and silica containing agents,
In can preservative is selected fromcomponent derivatives of thiazolinone and other ingredients of aldehyde.
Surfactant and Wetting Agents are from non-ionic surfactant (alcohol ethoxylate)as well as anionic surfactant like polycarboxylic acid salts.
Thickener involvedis non-ionic synthetic associative thickenerhaving polyurethane-ethoxylate component in the backbone and extender based on Kaolin, calcium carbonate and talc.
Coalescing agent and Flow and levelling agent areselected from components containing long chain ester alcohol.
Cured films obtained from the formulation/compositionin accordance with the present invention shows excellent scuff resistance e.g. rubs on various kind of objects such as Neoprene rubber, synthetic leather, natural leather, canvas cloth, painted wood, sunmica, jute, ink paper etc.
Table 2: Film characteristics attained of the present system/ formulation

Attributes Scuff resistance Block resistance Dirt pick up resistance (DPUR) stain performance scrub resistance crack bridging ability
Standard of measurement ASTM F 2497-05 ASTM D 4946 ASTM D 3719 STMTP-58 ASTM D 3719 AUS/NZ 4548
Results 94/100 9/10 9/10 147/150 passes 500 to 1000 cycle
upto 0.5 mm.

The cured films of the Polyurethane-acrylic hybrid pigmented systemexposed to xenon arc for 500 Hrs. shows consistence performance of Crack bridging ability (0.5mm).

Process for preparation of the formulation
Providing Water, Glycols (mono or di or polyfunctional glycols), Aqueous solution of 2-amino-2-methyl-1-propanol, Foam control agent, Antifungal agent/biocide, in can preservative, defoamer and surfactant and Wetting Agents) in a cleaned stainless-steel container.
Adding thickener including non-ionic synthetic associative polyurethane-ethoxylate thickenerunder slow speed stirring at RPM 400-600, white pigment (titanium dioxide)] at RPM 1200-1500 for 10 minutes followed by addition of extenders and checking the finish on panel at an interval of 10 minutes to ensure lump free dispersion.
Adding further coalescing agent, flow and levelling agents in said lump free dispersion followed by addition of acrylic emulsion (optionally involving styrene) and Polycarbonate polyurethane waterborne dispersion to the container and continued stirring at 700 RPM for 10 minutes.
The said acrylic emulsion was prepared by conventional procedures employing the monomers of acrylates and methacrylates, optionally involving styrene as monomer (5% to 15%)depending on the Tg of the copolymer to be achieved spanning the range of 25 deg C to -45 deg C.
Adding water, wax dispersion and fluro additives in the container and continued stirring at 700 RPM for 10 minutes to provide the desired dispersion having viscosity in the range of 90-110 KU Stormer viscometer at 30 °C and solid content by weight (%): 45 ± 1.5 at 120°C for 1 hour.
Example-2

Acrylics emulsion with Paraffin wax emulsion in the absence of polycarbonate polyurethane dispersion.

To evaluate the contribution of the polycarbonate polyurethane dispersion towards attaining the desired attributes of the formulation- the same formulation as of Example 1 was repeated devoid of polycarbonate polyurethane dispersion. The measured attributes of the formulation are as follows.
Performance enhancement
? Scrub resistance white Base:500+
? Sheen value: 40-65 @ 60 GH
Negative impacts
? Stain cleanability:140 out of 150
? Scuff resistance:80
? Block resistance:7
? Tactile feel-No tactile feel
? Crack bridging ability: 0.3
Although few of the attributes like scrub resistance and sheen values of the above comparative formulation was similar to the formulation in accordance with the present invention, but rest of the performances were much inferior.
Example-3
Asdisclosed under Example-1 above – the ratio of acrylicswith anionic Polycarbonate PUD (-45°C Tg and -1°C MFFT) and Paraffin wax dispersion was maintained at (81-91:5-15:1-9)w.r.t binder composition. Formulation was tried with excess % of Polycarbonate i.e. more than 10 % w.r.t binder composition at same solid levels of the polycarbonate PUD as under Table 1. The performance parameters of the prepared formulation are depicted in the followings:
Performance enhancement
? Scrub resistance white Base:500+
? Sheen value: 40-65 @ 60 GH
? Scuff resistance:90
? Tactile feel -Yes
? Crack bridging ability: 0.5

Negative impacts
? Stain cleanability:114 out of 150
? Block resistance:5
Example-4
Another formulation similar to Example-1 with Lower % of Polycarbonate (Less than 2wt. % w.r.t the binder was prepared and performance parameters were measured:
Performance enhancement
? Scrub resistance white Base:500+
? Sheen value: 40-65 @ 60 GH
? Stain cleanability:147 out of 150
? Block resistance:9
? Tactile feel -Yes
Negative impacts
? Scuff resistance:60-65
? Crack bridging ability: 0.2
The formulation exhibited Scuff resistance: 60-65 and Crack bridging ability: 0.2 which are much inferior compared to theformulation in accordance with the present invention of 90 and 0.5 respectively.

Example-5
Another formulation similar to Example-1 with 5 % of Paraffin wax dispersionmore than4 wt.% w.r.t binderwas prepared and performance parameters were measured:
Performance enhancement
? Sheen value: 40-65 @ 60 GH
? Stain cleanability:147 out of 150
? Crack bridging ability: 0.5
? Block resistance -9
? Tacktile feel -Yes
Negative impacts
? Scrub resistance white Base:200-250 only
? Scuff resistance:80

The formulation displays poor Scrub resistance white Base with 200-250 cycles only and inferior Scuff resistance of 80 compared to the same (more than 500 cycles and 94 respectively) for proposed formulation.

Example-6
Another formulation similar to Example-1 with Lower wt. % of Paraffin wax dispersion (less than 1 wt. % w.r.t binder) was prepared and performance parameters were measured:
Performance enhancement
? Scrub resistance white Base:500+
? Seen value: 40-65 @ 60 GH
? Scuff resistance:90
? Tacktile feel -Yes
? Crack bridging ability: 0.5

Negative impacts
? Stain cleanability:114 out of 150.
? Block resistance:5

Both Examples-5 and 6 provides formulation which have overall poorer performance parameters with respect to the synergistic formulation/system in accordance with the present invention.

Thus in one aspect the present advancement provides a Polyurethane-styreneacrylic copolymer emulsionbased hybrid pigmented systemhaving excellent stability without phase separation even after 5 cycles in freeze-thaw stability, and accelerated stability tests (stable at hot condition 55 Deg C for 30 days and cold condition -5 Deg C for 15 days)- which upon application and curing affords polymeric film having high gloss (45-60 unit @60 gloss head), scuff resistance(94 score out of 100), stain resistance (147 score out of 150), crack bridging ability (0.5 mm), Block resistance (rating 9 out of 10) thus attaining two contradictory properties like stain resistance, (block resistance and DPUR which are obtained by hard polymer film, and other properties like crack bridging ability which is due to the elasticity of the polymer film together. The composition is particularly suitable for high performance luxury finishes for the Interior wall decoration.
According to another embodiment of the present invention there is provided yet another polyurethane-acrylic hybrid coating system comprising an (a) select acrylic copolymer emulsion of Tg ranging from -45 to 5 deg C with a co-acting combination of (b) anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C, (c) 1 % to 4 wt.% wax dispersion (d) acrylic matting emulsion including internal light scattering microspheres as extreme matt interior wall coating system including said co-acting combination thereby enabling completely dead matt finish (less than <7 @85 G.H) superior scrub resistance, scuff resistance (R=94 out of 100), Stain resistance (Rating 147 out of 150) and dirt pick up resistance (DPUR) (R=9 out of 10) also along with crack bridging ability (up to 0.4 mm), and superior block resistance (R=9 out of 10).
In another embodiment, the present invention provides for extreme mattiness of said another polyurethane-acrylic hybrid coating systemthat is surprisingly achieved by designing paints backbone involving three combinations of(a) incorporation of limited % of matting agent in Paint backbone. (b) enhancing mattiness further by gloss reduction with Ceramic microsphere (c) creating Dead matt by structuring the polymer backbone involving acrylic co-polymer emulsion which gives strength to paints backbone without contributing to sheen /gloss value. Theenablement of completely dead matt finish (less than <7 @85 G.H) together with superior scrub resistance, scuff resistance (R=94 out of 100), Stain resistance (Rating 147 out of 150) and dirt pick up resistance (DPUR) (R=9 out of 10)along with crack bridging ability (up to 0.4 mm), and superior block resistance (R=9 out of 10) could be uniquely achieved by the present invention.

Uniqueness of the present formulation:
a. Significant matt finish (sheen value <3 @85 Gloss head on wall) with equal performance of high sheen like products (superior scrub resistance, scuff resistance (R=94 out of 100), Stain resistance (Rating 147 out of 150) and dirt pick up resistance (DPUR) (R=9 out of 10) along with crack bridging ability (up to 0.4 mm), and superior block resistance (R=9 out of 10).
b. Significant matt finish in low PVC paints category (<35) (generally all matt products have high PVC range >50-55)
c. Excellent burnishing resistance (as matting products have this issues of burnishing resistance).
d. Excellent smoothness (smooth and glide) (the products available in the public domain in matt category have limitation of smooth and glide appearance.)
e. First kind of coating system in matt category segments favouring matt finish with scuff resistance along with crack bridging ability.
Table 3:Formulation of thepolyurethane-acrylic hybrid coating system adapted for matt finish.
Sr.No Ingredients %PBW
1 WATER 5.74-22.5
2 Glycols (mono or di or polyfunctional glycols) 1.5-6
3 Neutralizer 2-amino-2-methyl-1-propanol in an aqueous solution 0.025-1
4 Foam control agent 0.07-0.3
5 Antifungal agent/biocide 0.3-1.5
6 In can preservative 0.05-0.2
7 defoamer 0.2-0.8
8 Surfactant and Wetting Agent 0.55-2.25
9 Thickener (non-ionic synthetic associative thickener) 0.5-2
10 White pigments(Titanium dioxide) 12-48
11 extenders 2.5-10
12 Coalescing agent 1.5-6
13 Flow and leveling agent 0.1-0.4
14 Acrylic emulsionof Tg ranging from -45 to 5 deg C 11-77
15 Polycarbonate polyurethane waterborne dispersion 2-10
16 Wax emulsion preferably silicone wax emulsion 1-4
17 Fluro copolymer 0.01-0.068
18 Matting emulsion 10-20

Table 4:Performance enhancement and comparatives with matting emulsion
Paint ingredients/Major component Performance enhancement Negative impacts

Case-(I) (acrylics IN004) with acrylic matting emulsion ? Sheen value <7 on glass plate and <3 on wall
? Scrub resistance white Base:500+
? Stain cleanability:140 out of 150
? Scuff resistance:80
? Block resistance:7 Lacks of PU like finish/feel
Case-(II) (acrylics IN004) with acrylic matting emulsion + anionic polyurethane waterborne dispersion ? Smooth and glide-PU like finish
? Stain cleanability:140 out of 150
? Scuff resistance: 94 out of 100
? Block resistance: (Rating -8)
? Flow and levelling-(Rating-9)
? Crack bridging ability:0.5 mm
? Tactile feel : Due to carbonate backbone
Stain resistance is slightly inferior( less than 120)
Case-(III) (acrylics IN004) with acrylic matting emulsion + anionic polyurethane waterborne dispersion +Silicon wax emulsion (Silicon wax contain poly siloxane as an ingredient )
Best polymer backbone:- Acrylic copolymer emulsion:acrylic matting emulsion:polycarbonate PUD :wax emulsion (70-80:10-20:7:3)
? Smooth and glide-PU like finish
? Stain cleanability:147 out of 150
? Scuff resistance: 94 out of 100
? Block resistance: (Rating -8)
? Flow and leveling-(Rating-9)
? Crack bridging ability:0.5 mm
? Excellent water resistance
Tactile feel : Due to carbonate backbone

There are no negative impacts with this composition.
Lower % of anionic polycarbonate PUD dispersion comparative of case –III (Less than 2wt. % w.r.t. binder) ? Inferior scuff resistance68
? (No effects on scrub resistance)

Excess % of silicon wax emulsion (more than 4 % w.r.t binder) comparative of case –III ? Loss of tactile feel, films becomes buttery
? Poor drying time (>30 min).
? Inferior scrub resistance.(68)
? High sheen value,loose matiness ( sheen more than 10 @ 85 G.H)
Lower % silicon wax emulsion) (less than 1% w.r.t. binder) ? Inferior stain resistance. <140)
? Poor block resistance-6 unit

It is thus possible for the present advancement to provide for coating formulations/system preferably interior wall coating formulations comprising co-acting blend/synergistic combination of acrylic copolymer (optionally involving styrene as monomer) emulsionof Tg range of from -45 to +25 deg C (including high and low Tg polymers) free of any hydroxyl value, aliphatic polyester polycarbonate based anionic polyurethane dispersion in paraffin wax dispersion/silicon wax emulsion enabling superior scrub resistance, scuff resistance (R=94 out of 100), Stain resistance (Rating 147 out of 150) and dirt pick up resistance (DPUR) (R=9 out of 10) along with crack bridging ability (up to 0.5 mm), and superior block resistance (R=9 out of 10), also adapted for dead matt finish (less than <7 @85 Gloss head) when present together with matting emulsion.
,CLAIMS:We Claim:
1. A polyurethane-acrylic hybrid coating system comprising
(a)22 to 88 wt.% acrylic copolymer emulsion having Tg ranging from 25 deg C to -45 deg C;
(b)2 to 10 wt.%anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C;
(c) 1 % to 4 wt. % wax dispersion;
as a synergistically co-acting combination in said coating system adapted for contradictory attributes of significant stain resistance, scuff resistance, DPUR, with significant crack bridging ability out of single coating system.
2. The polyurethane-acrylic hybrid coating system as claimed in claim 1 wherein said acrylic copolymer emulsion is a copolymer of acrylate and methacrylate monomers optionally involving styrene monomer (5-15 Wt%) of 48-52% solid content free of any hydroxyl valuefor inclusion in said coating system that is selectively surfactant stabilized based on select combination of non-ionic alcohol ethoxylates and anionic surfactant including polycarboxylic acid salts having particle size distribution of 100-500 nm at pH range of 7.5 to 9.5 for desired interlinking and coalescing of the latex particles with said anionic polycarbonate polyurethane dispersion of select particle size ranging from 100 nm to 300 nm having pH in the range of 7.5 to 8.5 and wax dispersion to result in cohesive and ductile film resulting in suitable scuff resistance attributes.
3. The polyurethane-acrylic hybrid coating system as claimed in claims 1 or 2 wherein said wax dispersion includes paraffin wax dispersion having wax content 10-30 % with 1 to 5 % C9 to C-11 & C16-18 Alcohols having 1 to 5% ethoxylated content; and said anionic polycarbonate polyurethane dispersion of 33-37% solid contentis solvent free aliphatic, polyester-polycarbonate based anionic polyurethane dispersion of said pH in the range of 7.5 to 9.5 and particle size distribution of100-300 nm.
4. The polyurethane-acrylic hybrid coating system as claimed in claims 1-3 wherein said ratio of styrene-acrylic copolymer emulsion: anionic polycarbonate polyurethane dispersion: wax dispersion is in the ratio range of 81-91:5-15:1-9 to enable desired attributes.
5. The polyurethane-acrylic hybrid coating system as claimed in claims 1-4 as self-curing room temperature curable non-reactive/non-condensable blend of said polymeric dispersions/emulsion.
6. The polyurethane-acrylic hybrid coating system as claimed in claims 1-5 includes coating ingredients of thickeners, defoamers, Glycols including mono or di or polyfunctional glycols, aqueous solution of 2-amino-2-methyl-1-propanol as neutralizer amine, pigments including opacifying pigment Titanium dioxide along with extender including Kaolin 20 to 40 wt.% having solvent in the levels of only <50 g/Lit and thereby is water borne coating system having excellent freeze-thaw stability without phase separation even after 5 cycles in relation to accelerated stability tests of being stable at hot condition of 55 Deg C for 30 days and stable at cold condition of -5 Deg C for 15 days, and is adapted for a cured coating film with a gloss value 45-60 unit @60 gloss head.
7. The polyurethane-acrylic hybrid coating system as claimed in claims 1-6 curable at ambient temperature suitable for luxury category finishes exhibiting high gloss (45-60 unit @60 gloss head), scuff resistance(94 score out of 100), stain resistance (147 score out of 150), crack bridging ability (0.5 mm), Block resistance (rating 9 out of 10), very high dirt pick up resistance (DPUR) (R=9 out of 10), excellent stain clean ability along with excellent scrub resistance (500-1000 cycle as per the ASTM D4213).
8. A method of manufacturing Polyurethane-acrylic hybrid coating system as claimed in claims 1-7 comprising
(a) providing said 22 to 88 wt% acrylic copolymer emulsion having Tg ranging from 25 deg C to -45 deg C,
(b) providing said 2 to 10 wt% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C
(c) providing said 1 to 4 wt.% wax dispersion for blending with said (a) and (b) preferably enabling a ratio range for components a:b:c of 81-91:5-15:1-9 to obtain therefrom said polyurethane-acrylic hybrid coating system.
9. The method of manufacturing of Polyurethane-acrylic hybrid coating systemas claimed in claim 8 wherein said coating system for inclusion of (a)-(c) above is first prepared by the following steps of
(i) Providing Water, Glycols including mono or di or polyfunctional glycols, Aq. solution of 2-amino-2-methyl-1-propanol as a neutralizer, Foam control agent, Antifungal agent/biocide, in-can preservative, defoamer together with surfactant and wetting agents;
(ii) Adding thickener including non-ionic synthetic associative thickener under slow speed stirring at RPM 400-600, white pigment including titanium dioxide at RPM 1200-1500 for 10 minutes followed by addition of extenders and evaluating the finish on panel at an interval of 10 minutes to ensure lump free dispersion;
(iii) Adding further Coalescing agent, Flow and levelling agents in said lump free dispersion followed by addition of styrene-acrylic emulsion that is stabilized by surfactants and anionic Polycarbonate polyurethane waterborne dispersion and continued stirring at 700 RPM for 10 minutes.
(iv) adding water, wax dispersion and additives including fluro additives with continued stirring at 700 RPM for 10 minutes to provide said polyurethane-acrylic hybridcoating systemhaving viscosity in the range of 90-110 KU Stormer viscometer at 30 °C and solid content by weight (%): 45 ± 1.5 at 120°C for 1 hour.
10. A polyurethane-acrylic hybrid coating system comprising
(a) 11 to 77 wt.% acrylic copolymer emulsion having Tg ranging from -45 deg C to 5 deg C;
(b) 2 to 10 wt.% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C;
(c) 1 % to 4 wt.% wax emulsion;
(d) 10% to 22wt.% matting emulsion having Tg range of -45 to 5 deg C and viscosity 500 to 1500 cps;
as a synergistically co-acting combination in said coating system adapted for contradictory attributes of significant stain resistance, scuff resistance, DPUR, with significant crack bridging ability out of single coating system advantageously adapted for matt finish.
11. The polyurethane-acrylic hybrid coating system as claimed in claim 10 wherein said Acrylic copolymer emulsion: polycarbonate PUD: wax emulsion preferably silicone wax emulsion: matting emulsion is in the ratio of (70-80:7:3:10-20)to enable desired attributes.
12. The polyurethane-acrylic hybrid coating system as claimed in claims 10 or 11 wherein said acrylic copolymer emulsion is a copolymer of acrylate and methacrylate monomers optionally including styrene monomer (5-15%) of 48-52% solid content free of any hydroxyl valuefor inclusion in said coating system that is selectively surfactant stabilized based on select combination of non-ionic alcohol ethoxylates and anionic surfactant including polycarboxylic acid salts having particle size distribution of 100-500 nm at pH range of 7.5 to 9.5 for desired interlinking and coalescing of the latex particles with said anionic polycarbonate polyurethane dispersion of select particle size ranging from 100 nm to 300 nm having pH in the range of 7.5 to 8.5 and wax emulsionto result in cohesive and ductile film resulting in suitable scuff resistance attributes.
13. The polyurethane-acrylic hybrid coating system as claimed in claims 10-12 wherein said wax emulsion is a silicone wax emulsion including polysiloxanesand said anionic polycarbonate polyurethane dispersion of 33-37% solid contentis solvent free aliphatic, polyester-polycarbonate based anionic polyurethane dispersion of said pH in the range of 7.5 to 9.5 and particle size distribution of100-300 nm.
14. The polyurethane-acrylic hybrid coating system as claimed in claims 10-13 as self-curing room temperature curable non-reactive/non-condensable blend of said polymeric dispersions/emulsion.
15. The polyurethane-acrylic hybrid coating system as claimed in claims 10-14 includes coating ingredients of thickeners, defoamers, Glycols including mono or di or polyfunctional glycols, aqueous solution of 2-amino-2-methyl-1-propanol as neutralizer amine, pigments including opacifying pigment Titanium dioxide along with extender including Kaolin 20 to 40 wt.% having solvent in the levels of only <50 g/Lit and thereby is water borne coating system having excellent freeze-thaw stability without phase separation even after 5 cycles in relation to accelerated stability tests of being stable at hot condition of 55 Deg C for 30 days and stable at cold condition of -5 Deg C for 15 days, and is adapted for a cured coating film with a dead matt finish of less than <7 @85 gloss head.
16. The polyurethane-acrylic hybrid coating system as claimed in claims 10-15 curable at ambient temperature suitable for luxury category finishes exhibiting dead matt finish of less than <7 @85 gloss head, scuff resistance(94 score out of 100), stain resistance (147 score out of 150), crack bridging ability (0.5 mm), Block resistance (rating 9 out of 10), very high dirt pick up resistance (DPUR) (R=9 out of 10), excellent stain clean ability along with excellent scrub resistance (500-1000 cycle as per the ASTM D4213).
17. A method of manufacturing Polyurethane-acrylic hybrid coating system as claimed in claims 10-16 comprising
(a) providing said 11 to 77 wt.% acrylic copolymer emulsion having high Tg ranging from -45 deg C to 5 deg C;
(b) providing said 2 to 10 wt.% anionic polycarbonate polyurethane dispersion having Tg -50 to -10 deg C;
(c) providing said 1 % to 4 wt.% wax emulsion;
(d) providing said 10% to 22wt.% matting emulsion having viscosity 500 to 1500 cps; for blending preferably in the ratio range of components a:b:c:d of 70-80:7:3:20-10 to obtain therefrom said polyurethane-acrylic hybrid coating system.
18. The method of manufacturing of Polyurethane-acrylic hybrid coating systemas claimed in claim 17 wherein said coating system for inclusion of (a)-(d) above is first prepared by the following steps of
(i) Providing water, Glycols including mono or di or polyfunctional glycols, aq. solution of 2-amino-2-methyl-1-propanol as a neutralizer, Foam control agent, Antifungal agent/biocide, in-can preservative, defoamer together with surfactant and wetting agents;
(ii) Adding thickener including non-ionic synthetic associative thickener under slow speed stirring at RPM 400-600, white pigment including titanium dioxide at RPM 1200-1500 for 10 minutes followed by addition of extenders and evaluating the finish on panel at an interval of 10 minutes to ensure lump free dispersion;
(iii) Adding further coalescing agent, Flow and leveling agents in said lump free dispersion followed by addition of acrylic copolymer emulsion that is stabilized by surfactants and anionic Polycarbonate polyurethane waterborne dispersion and continued stirring at 700 RPM for 10 minutes.
(iv) adding water, wax emulsion preferably silicone wax emulsion and additives including fluro additives with continued stirring at 700 RPM for 10 minutes to provide said polyurethane-acrylic hybridcoating systemhaving viscosity in the range of 90-110 KU Stormer viscometer at 30 °C and solid content by weight (%): 45 ± 1.5 at 120°C for 1 hour.

Dated this the 29thday of October 2022 Anjan Sen
Of Anjan Sen & Associates
(Applicants Agent)
IN/PA-199