A paint formulation and a process for its preparation

Abstract

The present disclosure relates to a paint formulation and a process for its preparation. The paint formulation comprises a graft copolymer emulsion and a functional paste. The paint formulation of the present disclosure is used for decorative and industrial applications. The paint formulation of the present disclosure is based on grafted copolymer technology and is water based with zero volatile organic compounds (VOC) hence, offers a sustainable, environment friendly solution with high performance properties. The present disclosure provide a simple and an economical process for the preparation of the paint formulation.

Description

[0001] A PAINT FORMULATION AND A PROCESS FOR ITS PREPARATION

[0002] FIELD

[0003] The present disclosure relates to a paint formulation and a process for its preparation.

[0004] DEFINITIONS

[0005] As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used, indicate otherwise.

[0006] Graft copolymer - refers to a type of a segmented copolymer where the polymer chains consists of a backbone and one or more side chains grafted onto it. These side chains are chemically different from the backbone.

[0007] Hard segment monomer-refers to a monomer that is used to prepare coatings, which imparts toughness, stabilization against UV, resistance to scratch and abrasion.

[0008] Soft segment monomer-refers to a monomer that is used to prepared coatings, which imparts flexibility, resistance to impact, elongation and moisture resistance and impermeability.

[0009] Reinforcing monomer-refers to a monomer that is used to prepare coatings, which imparts good adhesion properties, surface hardness, resistance to weathering and aging.

[0010] BACKGROUND

[0011] The background information herein below relates to the present disclosure but is not necessarily prior art.

[0012] The coating industry is experiencing robust growth, with a compound annual growth rate (CAGR) of 6.5% and a market potential projected to reach USD 168 billion. Driven by rapid infrastructure development, the demand for both decorative and industrial coatings is expected to rise significantly. As a result, the industry is shifting its focus beyond just performance, with sustainability emerging as a critical priority. However, conventional paint systems continue to release hazardous emissions that contribute to climate change, global warming, and pose serious health risks. Most of the conventional protective coatings are organic solvent based coatings and have a number of disadvantages. The solvent based coatings when applied on a surface release a large number of volatile organic compounds (VOCs) which are hazardous and impact the environment adversely. It is difficult to recycle and dispose of such coatings. Moreover, one coating is not enough to give a complete protection and therefore, multiple coatings of different materials are needed. It is also critical to mix various coating components in a specific proportion before application. Thus, such coating processes are time consuming and energy intensive. Further, the process of preparation of such coating / paint composition also includes VOCs. Therefore, neither the process of preparation of a conventional coating / paint nor its application on a surface is environment friendly.

[0013] Thus, there is felt a need to provide a paint formulation and a process for its preparation that mitigates the drawbacks mentioned herein above or at least provides an alternate solution.

[0014] OBJECTS

[0015] Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.

[0016] It is an object of the present disclosure is to ameliorate one or more problems of the background or to at least provide a useful alternative.

[0017] An object of the present disclosure is to provide a paint formulation.

[0018] Another object of the present disclosure is to provide a paint formulation that contains a graft copolymer emulsion.

[0019] Still another object of the present disclosure is to provide water based paint formulation.

[0020] Yet another object of the present disclosure is to provide a paint formulation that is devoid of any volatile organic compound (VOC) thus, environment friendly.

[0021] Still another object of the present disclosure is to provide a process for the preparation of a paint formulation which is devoid of an organic solvent.

[0022] Yet another object of the present disclosure is to provide a simple and economical process for the preparation of a paint formulation. Still another object of the present disclosure is to provide a paint formulation that has fast curing properties at room temperature.

[0023] Yet another object of the present disclosure is to provide a single pack (Ik) paint formulation.

[0024] Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

[0025] SUMMARY

[0026] The present disclosure relates to a paint formulation and a process for its preparation.

[0027] A paint formulation comprises:

[0028] • a graft copolymer emulsion; and

[0029] • a functional paste, wherein a weight ratio of the graft copolymer emulsion to the functional paste is in the range of 20:80 to 80:20.

[0030] The graft copolymer emulsion is a reaction product of:

[0031] • at least two monomers;

[0032] • an initiator;

[0033] • a buffer;

[0034] • at least one emulsifier; and

[0035] • water, wherein the monomers are selected from the group consisting of hard segment monomers, soft segment monomers, reinforcing monomers, cross linking monomers and bio-based monomers.

[0036] The monomers are present in an amount in the range of 15 mass% to 70 mass%;the initiator is present in an amount in the range of 0.1 mass% to 2 mass%; the buffer is present in an amount in the range of 0.1 mass% to 2 mass%; the emulsifier is present in an amount in the range of 0.5 mass% to 5 mass%; and water is present in an amount in the range of 30 mass% to 50 mass%, wherein the mass% of each ingredient is with respect to the total mass of the graft copolymer emulsion. The hard segment monomer is at least one selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene; the soft segment monomer is at least one selected from the group consisting of butyl acrylate monomer (BAM), ethyl acrylate monomer (EAM) and ethyl hexyl acrylate monomer (EHAM); the reinforcing monomer is at least one selected from the group consisting of maleic anhydride, acrylic acid, and methacrylic acid; the cross linking monomer is at least one selected from the group consisting of trifunctional monomers, acetoacetoxy ethyl methacrylate and trimethylol propane triacrylate; and the bio-based monomer is at least one selected from the group consisting of itaconic acid, vegetable oil, lignin derivatives, terpenes, proteins and carbohydrates.

[0037] The initiator is at least one selected from potassium persulfate and 2,2'-azobisisobutyronitrile; the buffer is selected from the group consisting of liquid ammonia solution, sodium carbonate and sodium hydrogen sulphate; and the emulsifier is a combination of an anionic emulsifier and a non-ionic emulsifier, wherein the anionic emulsifier is at least one selected from the group consisting of a fatty acid, sodium lauryl sulfate and alpha-olefin sulfonate, and the nonionic emulsifier is at least one selected from the group consisting of phosphate, ethoxylated alkyl alcohol, polyamines, amino alcohols and organic polyacid alkali salts.

[0038] A mass ratio of the hard segment monomer to the soft segment monomer in the monomers is in the range of 1 : 9 to 9: 1.

[0039] The functional paste comprises:

[0040] • 10 mass% to 30 mass% of at least one filler;

[0041] • 5 mass% to 20 mass% of at least one extender;

[0042] • 20 mass% to 70 mass% of a pigment;

[0043] • 1 mass% to 5 mass% of a dispersing agent; and

[0044] • 20 mass% to 80 mass% of water, wherein the mass% of each ingredient is with respect to the total mass of the functional paste.

[0045] The filler is at least one selected from the group consisting of silica, china clay, mica, talc and a combination thereof; the extender is at least one selected from the group consisting of zinc phosphate, barium sulphate and ceramic; the pigment is at least one selected from the group consisting of titanium dioxide, utox pigment, iron oxide, yellow oxide and chromium orange and the dispersing agent is at least one selected from the group consisting of an oil based dispersant, a silicone based dispersant, sodium polyacrylate, polyglycol ether, ethoxylated alkyl alcohol, ethoxylated alkyl phenol and ethoxylate and diester of alcohol acid.

[0046] The process comprises the following steps:

[0047] (A) preparing a graft copolymer emulsion by: i. mixing predetermined amounts of water, a buffer, an emulsifier and a first portion of an initiator in a reactor at a temperature in the range of 20 °C to 40 °C at a first predetermined stirring speed for a time period in the range of 10 minutes to 40 minutes to obtain a first mixture; ii. heating the first mixture to a temperature in the range of 50 °C to 80 °C under stirring at a second predetermined stirring speed, followed by adding predetermined amounts of a first hard segment monomer and a second portion of the initiator at a predetermined feed rate and pre-polymerizing to obtain a first polymer; iii. sequentially mixing predetermined amounts of a first soft segment monomer, a second hard segment monomer, a second soft segment monomer, optionally a cross linking monomer and a third hard segment monomer to the first polymer at the predetermined feed rate under stirring for a first predetermined time period to obtain a second polymer; iv. adding a predetermined amount of a bio-based monomer to the second polymer the predetermined feed rate under stirring for a second predetermined time period to obtain a third polymer; and v. sequentially mixing predetermined amounts of a first reinforcing monomer and a second reinforcing monomer to the third polymer under stirring at the predetermined feed rate and maintaining the reaction at a first predetermined temperature for a third predetermined time period followed by cooling to a second predetermined temperature to obtain the graft copolymer emulsion;

[0048] (B) separately preparing a functional paste by: a. mixing predetermined amounts of water and a dispersing agent under stirring at a speed in the range of 1200 rpm to 1600 rpm at a temperature in the range of 20 °C to 40 °C for a time period in the range of 10 minutes to 30 minutes to obtain a mixture; b. adding a predetermined amount of a pigment to the mixture under stirring for a time period in the range of 10 minutes to 30 minutes, followed by adding predetermined amounts of fdler and an extender under stirring for a time period in the range of 10 minutes to 30 minutes and continuing stirring for a time period in the range of 2 hours to 5 hours at a temperature in the range of 20 °C to 40 °C to obtain a functional paste; and c. mixing the graft copolymer emulsion (prepared in Step A) and the functional paste (prepared in step B) in a predetermined weight ratio under stirring at a stirring speed in the range of 100 rpm to 500 rpm for a time period in the range of 20 minutes to 50 minutes to obtain the paint formulation.

[0049] The at least one filler, the at least one extender and the pigment are separately ground in a mill by using ceramic balls having diameter in the range of 1.5 mm to 4 mm to obtain ground particles of the filler, the extender and the pigment.

[0050] Water in the step (i) is present in an amount in the range of 30 mass% to 50 mass%; the buffer is present in an amount in the range of 0.1 mass% to 2 mass%; the emulsifier is present in an amount in the range of 0.5 mass% to 5 mass%; the first portion of the initiator is present in an amount in the range of 0.01 mass% to 1 mass%; the first hard segment monomer is present in an amount in the range of 5 mass% to 20 mass%; the second portion of the initiator is present in an amount in the range of 0.01 mass% to 1 mass%; the second hard segment monomer is present in an amount in the range of 5 mass% to 15 mass%; the third hard segment monomer is present in an amount in the range of 1 mass% to 10 mass%; the first soft segment monomer is present in an amount in the range of 5 mass% to 15 mass%; the second soft segment monomer is present in an amount in the range of 5 mass% to 15 mass%; the first reinforcing monomer is present in an amount in the range of 0.05 mass% to 2 mass%; the bio-based monomer is present in an amount in the range of 0.5 mass% to 3 mass%; and the second reinforcing monomer is present in an amount in the range of 0.5 mass% to 3 mass%, wherein the mass% of each ingredient is with respect to the total mass of the graft copolymer emulsion. The first hard segment monomer, the second hard segment monomer and the third hard segment monomer are independently at least one selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene.

[0051] The first soft segment monomer and the second soft segment monomer are independently at least one selected from the group consisting of butyl acrylate monomer (BAM), ethyl acrylate monomer (EAM) and ethyl hexyl acrylate monomer (EHAM).

[0052] The first reinforcing monomer and the second reinforcing monomer are independently at least one selected from the group consisting of maleic anhydride, acrylic acid, and methacrylic acid.

[0053] The cross linking monomer is selected from the group consisting of trifunctional monomers, acetoacetoxy ethyl methacrylate and trimethylol propane triacrylate.

[0054] The bio-based monomer is selected from the group consisting of itaconic acid, vegetable oil, lignin derivatives, terpenes, proteins and carbohydrates.

[0055] The initiator is selected from potassium persulfate and 2, 2'-azobisisobutyronitrile.

[0056] The buffer is selected from the group consisting of liquid ammonia solution, sodium carbonate and sodium hydrogen sulphate.

[0057] The emulsifier is a combination of an anionic emulsifier and a non-ionic emulsifier, wherein the anionic emulsifier is at least one selected from the group consisting of fatty acid, sodium lauryl sulfate and alpha-olefin sulfonate; and the non-ionic emulsifier is at least one selected from the group consisting of phosphate, polyamines, ethoxylated alkyl alcohol, amino alcohols and organic polyacid alkali salts.

[0058] The dispersing agent is present in an amount in the range of 1 mass% to 5 mass%; the pigment is present in an amount in the range of 20 mass% to 70 mass%; the filler is present in an amount in the range of 10 mass% to 30 mass%; the extender is present in an amount in the range of 5 mass% to 20 mass%; water is present in an amount in the range of 20 mass% to 80 mass%, wherein mass% of each ingredient is with respect to the total mass of the functional paste. The dispersing agent is selected from the group consisting of an oil based dispersant, a silicone based dispersant, sodium polyacrylate, polyglycol ether, ethoxylated alkyl alcohol, ethoxylated alkyl phenol and ethoxylate and diester of alcohol acid; the pigment is selected from the group consisting of titanium dioxide, Utox pigment, iron oxide, yellow oxide and chromium orange; the filler is selected from the group consisting of silica, china clay, mica, talc and a combination thereof; and the extender is selected from the group consisting of zinc phosphate, barium sulphate and ceramic.

[0059] The first predetermined stirring speed is in the range of 50 rpm to 150 rpm; the second predetermined stirring speed is in the range of 50 rpm to 150 rpm; the first predetermined temperature is in the range of 70 °C to 95 °C; the second predetermined temperature is in the range of 30 °C to 50 °C; the first predetermined time period is in the range of 15 minutes to 60 minutes; the second predetermined time period is in the range of 5 minutes to 20 minutes; the third predetermined time period is in the range of 2 hours to 5 hours and the predetermined feed rate is in the range of 100 grams per minute to 300 grams per minute.

[0060] The predetermined weight ratio of the graft copolymer emulsion to the functional paste is in the range of 20:80 to 80:20.

[0061] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

[0062] The present disclosure will now be described with the help of accompanying drawing, in which

[0063] Figure 1 illustrates a schematic process of synthesis of a graft copolymer from a plurality of monomers, in accordance with an embodiment of the present disclosure.

[0064] Figure 2 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on scratch hardness properties of the paint formulation in accordance with the present disclosure; Figure 3 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on flexibility properties of the paint formulation in accordance with the present disclosure;

[0065] Figure 4 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on adhesion properties of the paint formulation in accordance with the present disclosure;

[0066] Figure 5 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on salt spray resistant properties of the paint formulation in accordance with the present disclosure;

[0067] Figure 6 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on water resistant properties of the paint formulation in accordance with the present disclosure;

[0068] Figure 7 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on heat insulation properties of the paint formulation in accordance with the present disclosure; and

[0069] DETAILED DESCRIPTION

[0070] The present disclosure relates to a paint formulation and a process for its preparation.

[0071] Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.

[0072] Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details, are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0073] The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units, and / or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.

[0074] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements.

[0075] The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer, or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.

[0076] The conventional coating systems prevalent in the industry today present several critical drawbacks that hinder their sustainability and efficiency. Conventional coatings, primarily composed of organic solvent-based formulations release significant amounts of volatile organic compounds (VOCs) during both preparation and application, contributing to environmental pollution, climate change, and adverse health effects. Additionally, such coatings are challenging to recycle or dispose of safely. Their application often requires multiple layers of different materials to achieve adequate protection, making the process labor-intensive and time-consuming. Precise mixing of components in specific ratios is also essential, increasing the complexity and likelihood of error. Furthermore, the preparation process itself involves VOC-emitting substances, rendering the entire lifecycle of conventional coatings environmentally harmful and inefficient. These limitations underscore the urgent need for advanced, eco-friendly alternatives that can offer both high performance and environmental safety.

[0077] The present disclosure provides a paint formulation and a process for its preparation.

[0078] In an aspect, the present disclosure provides a paint formulation. The paint formulation comprises:

[0079] • a graft copolymer emulsion; and

[0080] • a functional paste, wherein a weight ratio of the graft copolymer emulsion and the functional paste is in the range of 20: 80 to 80:20.

[0081] In an exemplary embodiment of the present disclosure, the weight ratio of the graft copolymer emulsion to the functional paste is 80:20. In another exemplary embodiment of the present disclosure, the weight ratio of the graft copolymer emulsion to the functional paste is 60:40. In still another exemplary embodiment of the present disclosure, the weight ratio of the graft copolymer emulsion to the functional paste 40:60. In yet another exemplary embodiment of the present disclosure, the weight ratio of the graft copolymer emulsion to the functional paste is 20:80.

[0082] The graft copolymer emulsion is a reaction product of:

[0083] • at least two monomers;

[0084] • an initiator;

[0085] • a buffer;

[0086] • at least one emulsifier; and

[0087] • water, wherein the monomers are selected from the group consisting of hard segment monomers, soft segment monomers, reinforcing monomers, cross linking monomers and bio-based monomers.

[0088] In an embodiment of the present disclosure, the monomers are present in an amount in the range of 15 mass% to 70 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of monomers is 48.22 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of monomers is 46.05 mass% with respect to the total mass of the graft copolymer emulsion.

[0089] In an embodiment of the present disclosure, the hard segment monomer is at least one selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene. In an exemplary embodiment of the present disclosure, the hard segment monomer is methyl methacrylate (MMA).

[0090] In an embodiment of the present disclosure, the hard segment monomers are present in an amount in the range of 10 mass% to 50 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the hard segment monomers is 25.57 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the hard segment monomers is 24.42 mass% with respect to the total mass of the graft copolymer emulsion.

[0091] The hard segment monomer imparts toughness, UV stabilization and resistance to scratches to the graft copolymer.

[0092] In an embodiment of the present disclosure, the soft segment monomer is at least one selected from the group consisting of butyl acrylate monomer (BAM), ethyl acrylate monomer (EAM) and ethyl hexyl acrylate monomer (EHAM). In an exemplary embodiment of the present disclosure, the soft segment monomer is butyl acrylate monomer (BAM).

[0093] In an embodiment of the present disclosure, the soft segment monomers are present in an amount in the range of 5 mass% to 30 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the soft segment monomers is 19.30 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the soft segment monomers is 18.44 mass% with respect to the total mass of the graft copolymer emulsion.

[0094] The soft segment monomers impart flexibility, impact resistance, elongation, moisture resistance and impermeability to the graft copolymer.

[0095] In an embodiment of the present disclosure, the reinforcing monomer is at least one selected from the group consisting of maleic anhydride, acrylic acid, and methacrylic acid. In an exemplary embodiment of the present disclosure, the reinforcing monomers are maleic anhydride and acrylic acid.

[0096] In an embodiment of the present disclosure, the reinforcing monomers are present in an amount in the range of 0.4 mass% to 5 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the reinforcing monomers is 1.77 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the reinforcing monomers is 1.69 mass% with respect to the total mass of the graft copolymer emulsion.

[0097] The reinforcing monomer imparts adhesion promotion, surface hardness, weathering resistance and aging resistance to the graft copolymer.

[0098] In an embodiment of the present disclosure, the crosslinking monomer is at least one selected from the group consisting of trifunctional monomers, acetoacetoxy ethyl methacrylate and trimethylol propane triacrylate. In an exemplary embodiment of the present disclosure, the crosslinking monomer is acetoacetoxy ethyl methacrylate (AAEM).

[0099] In an embodiment of the present disclosure, the crosslinking monomer is present in an amount in the range of 5 mass% to 10 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the crosslinking monomer is 4.48 mass% with respect to the total mass of the graft copolymer emulsion.

[0100] In an embodiment of the present disclosure, the bio-based monomer is at least one selected from the group consisting of itaconic acid, vegetable oil, lignin derivatives, terpenes, proteins and carbohydrates. In an exemplary embodiment of the present disclosure, the bio-based monomer is itaconic acid.

[0101] In an embodiment of the present disclosure, the bio-based monomer is present in an amount in the range of 0.5 mass% to 3 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the bio-based monomer is 1.56 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the bio-based monomer is 1.49 mass% with respect to the total mass of the graft copolymer emulsion.

[0102] In an embodiment of the present disclosure, a mass ratio of the hard segment monomer to the soft segment monomer in the monomers is in the range of 1:9 to 9: 1. In an exemplary embodiment of the present disclosure, a mass ratio of the hard segment monomer to the soft segment monomer in the monomers is 1.32: 1. In an embodiment of the present disclosure, the initiator is at least one selected from potassium persulfate and 2, 2'-azobisisobutyronitrile. In an exemplary embodiment of the present disclosure, the initiator is potassium persulfate.

[0103] In an embodiment of the present disclosure, the initiator is present in an amount in the range of 0.1 mass% to 2 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the initiator is 0.16 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the initiator is 0.15 mass% with respect to the total mass of the graft copolymer emulsion.

[0104] In an embodiment of the present disclosure, the buffer is at least one selected from the group consisting of liquid ammonia solution, sodium carbonate and sodium hydrogen sulphates. In an exemplary embodiment of the present disclosure, the buffer is liquid ammonia solution.

[0105] In an embodiment of the present disclosure, the buffer is present in an amount in the range of 0.1 mass% to 2 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the buffer is 1.56 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the buffer is 1.49 mass% with respect to the total mass of the graft copolymer emulsion.

[0106] In an embodiment of the present disclosure, the emulsifier is at least one selected from the group consisting of an anionic emulsifier and a non-ionic emulsifier, wherein the anionic emulsifier is at least one selected from the group consisting of fatty acid, sodium lauryl sulfate and alpha-olefin sulfonate, and the non-ionic emulsifier is selected from the group consisting of phosphate, ethoxylated alkyl alcohol, polyamines, amino alcohols and organic polyacid alkali salts. In an exemplary embodiment of the present disclosure, the emulsifier is a mixture of sodium lauryl sulfate (SLS) and ethoxylated alkyl alcohol.

[0107] In an embodiment of the present disclosure, the emulsifier is present in an amount in the range of 0.5 mass% to 5 mass% with respect to the total mass of graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the emulsifier is 0.99 mass% with respect to the total mass of graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the emulsifier is 0.94 mass% with respect to the total mass of graft copolymer emulsion. In an embodiment of the present disclosure, water acts as solvent. The graft copolymer emulsion and paint formulation is devoid of petroleum based solvents.

[0108] The functional paste comprises:

[0109] • 10 mass% to 30 mass% of at least one filler;

[0110] • 5 mass% to 20 mass% of at least one extender;

[0111] • 20 mass% to 70 mass% of a pigment;

[0112] • 1 mass% to 5 mass% of a dispersing agent; and

[0113] • 20 mass% to 80 mass% of water, wherein the mass% of each ingredient is with respect to the total mass of the functional paste.

[0114] In an embodiment of the present disclosure, the filler is selected from the group consisting of silica, china clay, mica, talc and a combination thereof. In an exemplary embodiment of the present disclosure, the filler is a combination of silica, china clay, mica and talc.

[0115] In an embodiment of the present disclosure, the filler is present in an amount in the range of 10 mass% to 30 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of filler is 14.63 mass% with respect to the total mass of the functional paste.

[0116] The fillers improve surface properties of final coating.

[0117] In an embodiment of the present disclosure, the extender is at least one selected from the group consisting of zinc phosphate, barium sulphate and ceramic. In an exemplary embodiment of the present disclosure, the extender is barium sulphate.

[0118] In an embodiment of the present disclosure, the extender is present in an amount in the range of 5 mass% to 20 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of extender is 7.31 mass% with respect to the total mass of the functional paste.

[0119] The extenders such as zinc phosphate improve corrosion resistance property while barium sulphate and ceramic impart heat insulation properties to final coating.

[0120] In an embodiment of the present disclosure, the pigment is at least one selected from the group consisting of titanium dioxide, utox pigment, iron oxide, yellow oxide and chromium orange. In an exemplary embodiment of the present disclosure, the pigment is titanium dioxide.

[0121] Utox is titanium dioxide substitute. UTOX is buff titanium with titanium dioxide contents around 94%.

[0122] In an embodiment of the present disclosure, the pigment is present in an amount in the range of 20 mass% to 70 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of pigment is 48.78 mass% with respect to the total mass of the functional paste.

[0123] In an embodiment of the present disclosure, the dispersing agent is at least one selected from the group consisting of an oil based dispersant, a silicone based dispersant, sodium polyacrylate, polyglycol ether, ethoxylated alkyl alcohol (SPECTRA APF 115), ethoxylated alkyl phenol (SPECTRA TRK) and ethoxylate and diester of alcohol acid (SPECTRA TY). In an exemplary embodiment of the present disclosure, the dispersing agent is sodium polyacrylate.

[0124] In an embodiment of the present disclosure, the dispersing agent is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of dispersing agent is 4.87 mass% with respect to the total mass of the functional paste.

[0125] In an embodiment of the present disclosure, the water is present in an amount in the range of 20 mass% to 80 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of water is 24.39 mass% with respect to the total mass of the functional paste.

[0126] The desired properties of the paint formulation are achieved by the graft copolymer emulsion of the present disclosure, wherein the appropriate selection of the monomers plays crucial role in achieving graft structure.

[0127] In another aspect, the present disclosure provides a process for the preparation of a paint formulation. The process comprises the following steps:

[0128] (A) preparing a graft copolymer emulsion by: i. mixing predetermined amount of water, a buffer, an emulsifier and a first portion of an initiator in a reactor at a temperature in the range of 20 °C to 40 °C at a first predetermined stirring speed for a time period in the range of 10 minutes to 40 minutes to obtain a first mixture; ii. heating the first mixture to a temperature in the range of 50 °C to 80 °C under stirring at a second predetermined stirring speed, followed by adding predetermined amounts of a first hard segment monomer and a second portion of the initiator at a predetermined feed rate and pre-polymerizing to obtain a first polymer; iii. sequentially mixing predetermined amounts of a first soft segment monomer, a second hard segment monomer, a second soft segment monomer, optionally a cross linking monomer and a third hard segment monomer to the first polymer at the predetermined feed rate under stirring for a first predetermined time period to obtain a second polymer; iv. adding a predetermined amount of a bio-based monomer to the second polymer the predetermined feed rate under stirring for a second predetermined time period to obtain a third polymer; and v. sequentially mixing predetermined amounts of a first reinforcing monomer and a second reinforcing monomer to the third polymer under stirring at the predetermined feed rate and maintaining the reaction at a first predetermined temperature for a third predetermined time period followed by cooling to a second predetermined temperature to obtain the graft copolymer emulsion;

[0129] (B) separately preparing a functional paste by: a. mixing predetermined amounts of water and a dispersing agent under stirring at a speed in the range of 1200 rpm to 1600 rpm at a temperature in the range of 20 °C to 40 °C for a time period in the range of 10 minutes to 30 minutes to obtain a mixture; b. adding a predetermined amount of a pigment to the mixture under stirring for a time period in the range of 10 minutes to 30 minutes, followed by adding predetermined amounts of filler and an extender under stirring for a time period in the range of 10 minutes to 30 minutes and continuing stirring for a time period in the range of 2 hours to 5 hours at a temperature in the range of 20 °C to 40°C to obtain the functional paste; and c. mixing the graft copolymer emulsion (prepared in Step A) and the functional paste (prepared in step B) in a predetermined weight ratio under stirring at a speed in the range of 100 rpm to 500 rpm for a time period in the range of 20 minutes to 50 minutes to obtain the paint formulation.

[0130] The process is explained in detail.

[0131] Step (A): Preparing a graft copolymer emulsion

[0132] In an embodiment of the present disclosure, the graft copolymer is synthesized by using emulsion polymerization technique.

[0133] Sub-step (i): In a first sub-step of Step (A), predetermined amounts of water, a buffer, an emulsifier and a first portion of an initiator are mixed in a reactor at a temperature in the range of 20 °C to 40 °C at a first predetermined stirring speed for a time period in the range of 10 minutes to 40 minutes to obtain a first mixture.

[0134] The reactor, three neck round bottom flask is provided with stirring means, condenser, which is placed in hot water bath having electric heating system and inlet / outlet opening for heating and / cooling reactants during polymerization process.

[0135] The predetermined amount of water in the step (i) is in the range of 30 mass% to 50 mass% with respect to the total amount of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the predetermined amount of water is 49.06 mass% with respect to the total amount of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the predetermined amount of water is 46.85 mass% with respect to the total amount of the graft copolymer emulsion.

[0136] The buffer is at least one selected from the group consisting of liquid ammonia solution, sodium carbonate and sodium hydrogen sulphate. In an exemplary embodiment of the present disclosure, the buffer is liquid ammonia solution.

[0137] The predetermined amount of the buffer is in the range of 0.1 mass% to 2 mass% with respect to the total amount of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the predetermined amount of the buffer is 1.56 mass% with respect to the total amount of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the predetermined amount of the buffer is 1.49 mass% with respect to the total amount of the graft copolymer emulsion.

[0138] In an embodiment of the present disclosure, the emulsifier is at least one selected from the group consisting of an anionic emulsifier and a non-ionic emulsifier, wherein the anionic emulsifier is selected from the group consisting of a fatty acid, sodium lauryl sulfate and alpha-olefin sulfonate and the non-ionic emulsifier is selected from the group consisting of phosphate, polyamines, amino alcohols and organic polyacid alkali salts. In an exemplary embodiment of the present disclosure, the emulsifier is a mixture of sodium lauryl sulphate and ethoxylated alkyl alcohol.

[0139] The predetermined amount of the emulsifier is in the range of 0.5 mass% to 5 mass% with respect to the total amount of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the predetermined amount of the emulsifier is 0.99 mass% with respect to the total amount of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the predetermined amount of the emulsifier is 0.94 mass% with respect to the total amount of the graft copolymer emulsion.

[0140] In accordance with the present disclosure, a mixture of emulsifiers is used to achieve particle size of graft copolymer close to nano level and to completely convert entire monomer combinations to the copolymer molecule. The selection of the emulsifiers and the ratio of the emulsifiers is critical and plays important role in achieving desired performance properties. This also helps in achieving final copolymer molecule without free monomers. This helps in making the final coating with “No odor” and “No hazardous emissions”.

[0141] In an embodiment of the present disclosure, the initiator is at least one selected from potassium persulfate and 2, 2'-azobisisobutyronitrile. In an exemplary embodiment of the present disclosure, the initiator is potassium persulfate.

[0142] The predetermined amount of the first portion of the initiator is in the range of 0.01 mass% to 1 mass% with respect to the total amount of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the predetermined amount of the first portion of the initiator is 0.10 mass% with respect to the total amount of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the predetermined amount of the first portion of the initiator is 0.09 mass% with respect to the total amount of the graft copolymer emulsion.

[0143] In an exemplary embodiment of the present disclosure, the temperature is 25 °C.

[0144] In an embodiment of the present disclosure, the first stirring speed is in the range of 50 rpm to 150 rpm. In an exemplary embodiment of the present disclosure, the first stirring speed is 100 rpm.

[0145] In an exemplary embodiment of the present disclosure, the time period is 20 minutes.

[0146] Sub-step (ii): In a second sub-step of Step (A), the first mixture is heated to a temperature in the range of 50 °C to 80 °C under stirring at a second predetermined stirring speed, followed by adding predetermined amounts of a first hard segment monomer and a second portion of the initiator at a predetermined feed rate and pre-polymerizing to obtain a first polymer.

[0147] The so obtained first mixture is heated to a temperature in the range of 50 °C to 80 °C under stirring. In an exemplary embodiment of the present disclosure, the first mixture is heated at 70 °C.

[0148] In an embodiment of the present disclosure, the second stirring speed is in the range of 50 rpm to 150 rpm. In an exemplary embodiment of the present disclosure, the second string speed is 130 rpm.

[0149] The first hard segment monomer is at least one selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene. In an exemplary embodiment of the present disclosure, the first hard segment monomer is methyl methacrylate (MMA).

[0150] The amount of the first hard segment monomer is present in an amount in the range of 5 mass% to 20 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the first hard segment monomer is 13.56 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the first hard segment monomer is 12.95 mass% with respect to the total mass of the graft copolymer emulsion. The initiator is at least one selected from potassium persulfate and 2, 2'- azobisisobutyronitrile. In an exemplary embodiment of the present disclosure, the initiator is potassium persulfate.

[0151] The second portion of the initiator is present in an amount in the range of 0.01 mass% to 1 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the second portion of the initiator is 0.06 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the second portion of the initiator is 0.05 mass% with respect to the total mass of the graft copolymer emulsion.

[0152] The second portion of the initiator is 20% solution in water.

[0153] In an embodiment of the present disclosure, the predetermined feed rate is in the range of 100 grams / minute to 300 grams / minute. In an exemplary embodiment of the present disclosure, the feed rate is 200 grams / minute.

[0154] Sub-step (iii): In a third sub-step of Step (A), predetermined amounts of a first soft segment monomer, a second hard segment monomer, a second soft segment monomer, optionally a cross linking monomer and a third hard segment monomer are mixed sequentially to the first polymer at the predetermined feed rate for a first predetermined time period to obtain a second polymer.

[0155] In an embodiment of the present disclosure, the first soft segment monomer and the second soft segment monomer are independently selected from the group consisting of butyl acrylate monomer (BAM), ethyl acrylate monomer (EAM) and ethyl hexyl acrylate monomer (EHAM). In an exemplary embodiment of the present disclosure, the first soft segment monomer is butyl acrylate monomer (BAM) and the second soft segment monomer is ethyl hexyl acrylate (EHA).

[0156] The first soft segment monomer is present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the first soft segment monomer is 10.43 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the first soft segment monomer is 9.96 mass% with respect to the total mass of the graft copolymer emulsion. The second soft segment monomer is present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the second soft segment monomer is 8.87 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the second soft segment monomer is 8.47 mass% with respect to the total mass of the graft copolymer emulsion.

[0157] In an embodiment of the present disclosure, the cross linking monomer is selected from the group consisting of trifimctional monomers, acetoacetoxy ethyl methacrylate and trimethylol propane triacrylate. In an exemplary embodiment of the present disclosure, the crosslinking monomer is acetoacetoxy ethyl methacrylate (AAEM).

[0158] In an embodiment of the present disclosure, the crosslinking monomer is present in an amount in the range of 5 mass% to 10 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the crosslinking monomer is 4.48 mass% with respect to the total mass of the graft copolymer emulsion.

[0159] The second hard segment monomer and the third hard segment monomer are selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene. In an exemplary embodiment of the present disclosure, the second hard segment monomer is butyl methacrylate (BMA) and the third hard segment monomer is styrene.

[0160] The second hard segment monomer is present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the second hard segment monomer is 7.82 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the second hard segment monomer is 7.47 mass% with respect to the total mass of the graft copolymer emulsion.

[0161] The third hard segment monomer is present in an amount in the range of 1 mass% to 10 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the third hard segment monomer is 4.17 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the third hard segment monomer is 3.98 mass% with respect to the total mass of the graft copolymer emulsion.

[0162] In an embodiment of the present disclosure, the predetermined feed rate is in the range of 100 grams / minute to 300 grams / minute. In an exemplary embodiment of the present disclosure, the feed rate is 200 grams / minute.

[0163] In an embodiment of the present disclosure, the first predetermined time period is in the range of 15 minutes to 60 minutes. In an exemplary embodiment of the present disclosure, the first time period is 15 minutes.

[0164] Sub-step (iv): In a fourth sub-step of Step (A), a predetermined amount of a bio-based monomer is added to the second polymer at the predetermined feed rate under stirring for a second predetermined time period to obtain a third polymer.

[0165] In an embodiment of the present disclosure, the bio-based monomer is selected from the group consisting of itaconic acid, vegetable oil, lignin derivatives, terpenes, proteins and carbohydrates. In an exemplary embodiment of the present disclosure, the bio-based monomer is itaconic acid.

[0166] In an embodiment of the present disclosure, the predetermined amount of a bio-based monomer is in the range of 0.5 mass% to 3 mass% with respect to the total amount of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the bio-based monomer is 1.56 mass% with respect to the total amount of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the bio-based monomer is 1.49 mass% with respect to the total amount of the graft copolymer emulsion.

[0167] In an embodiment of the present disclosure, the predetermined feed rate is in the range of 100 grams / minute to 300 grams / minute. In an exemplary embodiment of the present disclosure, the feed rate is 200 grams / minute.

[0168] The feed rate in the range of 100 grams / minute to 300 grams / minute is crucial for the control of the particle size of polymer micelle. Beyond this range of feeding rate, desired particle size of the micelle cannot be achieved. In an embodiment of the present disclosure, the second predetermined time period is in the range of 5 minutes to 20 minutes. In an exemplary embodiment of the present disclosure, the time period is 15 minutes.

[0169] Sub-step (v): In a fifth sub-step of Step (A), predetermined amounts of a first reinforcing monomer and a second reinforcing monomer are mixed sequentially to the third polymer under stirring at the predetermined feed rate and maintaining the reaction at a first predetermined temperature for a third predetermined time period to obtain a graft copolymer emulsion.

[0170] In an embodiment of the present disclosure, the first reinforcing monomer and the second reinforcing monomer are independently selected from the group consisting of maleic anhydride, acrylic acid, and methacrylic acid. In an exemplary embodiment of the present disclosure, the first reinforcing monomers are maleic anhydride and the second reinforcing monomer is acrylic acid.

[0171] The first reinforcing monomer is present in an amount in the range of 0.05 mass% to 2 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of the first reinforcing monomer is 0.20 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of the first reinforcing monomer is 0.19 mass% with respect to the total mass of the graft copolymer emulsion.

[0172] The second reinforcing monomer is present in an amount in the range of 0.5 mass% to 3 mass% with respect to the total mass of the graft copolymer emulsion. In an exemplary embodiment of the present disclosure, the amount of second reinforcing monomer is 1.56 mass% with respect to the total mass of the graft copolymer emulsion. In another exemplary embodiment of the present disclosure, the amount of second reinforcing monomer is 1.49 mass% with respect to the total mass of the graft copolymer emulsion.

[0173] In an embodiment of the present disclosure, the third predetermined time period is in the range of 2 hours to 5 hours. In an exemplary embodiment of the present disclosure, the third predetermined time period is 3 hours.

[0174] In an embodiment of the present disclosure, the first predetermined temperature is in the range of 70 °C to 95 °C. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 80 °C. Sub-step (vi): In a sixth sub-step of Step (A), the graft copolymer emulsion is cooled to a second predetermined temperature to obtain the graft copolymer emulsion.

[0175] In an embodiment of the present disclosure, the second predetermined temperature is in the range of 30 °C to 50 °C. In an exemplary embodiment of the present disclosure, the second predetermined temperature is 40 °C.

[0176] The addition pattern of the monomers of the present disclosure is designed in such a way that it creates a morphology or arrangement of hard, soft and reinforcing monomer chains in a specific pattern. This pattern results into achieving critical performance properties including water vapor impermeability and high anti carbonation values. The performance parameters enable the coating to be effective at a lower dry film thickness of 100 microns, compared to the 300 microns typically required by conventional solvent-based and waterborne paint formulations.

[0177] Step IB): Preparing a functional paste

[0178] Sub-step (a): In a first sub-step of Step (B), predetermined amounts of water and a dispersing agent are mixed under stirring at a speed in the range of 1200 rpm to 1600 rpm at a temperature in the range of 20 °C to 40 °C for a time period in the range of 10 minutes to 30 minutes to obtain a mixture.

[0179] The predetermined amount of water is in the range of 20 mass% to 40 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of water is 24.39 mass% with respect to the total mass of the functional paste.

[0180] In an embodiment of the present disclosure, the dispersing agent is at least one selected from the group consisting of oil based dispersant, silicone based dispersant, sodium polyacrylate, polyglycol ether, ethoxylated alkyl alcohol, ethoxylated alkyl phenol and ethoxylate and diester of alcohol acid. In an exemplary embodiment of the present disclosure, the dispersing agent is sodium polyacrylate.

[0181] In an embodiment of the present disclosure, the dispersing agent is present in an amount in the range of 1 mass% to 5 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of dispersing agent is 4.87 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the stirring speed is 1440 rpm.

[0182] In an exemplary embodiment of the present disclosure, the temperature is 27 °C.

[0183] In an exemplary embodiment of the present disclosure, the time period is 15 minutes.

[0184] Sub-step (b):In a second sub-step of Step (B), a predetermined amount of a pigment is added to the mixture under stirring for a time period in the range of 10 minutes to 30 minutes, followed by adding a predetermined amount of at least one fdler under stirring for a time period in the range of 10 minutes to 30 minutes and continuing stirring for a time period in the range of 2 hours to 5 hours at a temperature in the range of 20 °C to 40 °C to obtain the functional paste.

[0185] In an embodiment of the present disclosure, the fdler, the extender, the pigment are separately ground in a mill using ceramic balls having diameter in the range of 1.5 mm to 4 mm (grinding medium) to obtain ground particles of the fdler, the extender and the pigment.

[0186] The functional paste is prepared in a vertical mill fitted with a stirrer.

[0187] In an embodiment of the present disclosure, the pigment is at least one selected from the group consisting of titanium dioxide, utox pigment, iron oxide, yellow oxide and chromium orange. In an exemplary embodiment of the present disclosure, the pigment is titanium dioxide.

[0188] In an embodiment of the present disclosure, the pigment is present in an amount in the range of 20 mass% to70 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of pigment is 48.78 mass% with respect to the total mass of the functional paste.

[0189] In an exemplary embodiment of the present disclosure, the pigment is added over a time period of 15 minutes.

[0190] In an embodiment of the present disclosure, the filler is selected from the group consisting of silica, china clay, mica, talc and a combination thereof. In an exemplary embodiment of the present disclosure, the filler is a combination of silica, china clay, mica and talc.

[0191] In an embodiment of the present disclosure, the filler is present in an amount in the range of 10 mass% to 30 mass% with respect to the total mass of the functional paste. In an exemplary embodiment of the present disclosure, the amount of filler is 14.63 mass% with respect to the total mass of the functional paste.

[0192] In an exemplary embodiment of the present disclosure, the filler is added over 15 minutes and the stirring is continued for 2 hours at 35 °C to obtain a functional paste.

[0193] The graft copolymer emulsion (prepared in Step A) and the functional paste (prepared in step B) are mixed in a predetermined weight ratio under stirring at a speed in the range of 100 rpm to 500 rpm for a time period in the range of 20 minutes to 50 minutes to obtain the paint formulation.

[0194] In an embodiment of the present disclosure, the mixing is carried out in a metal tank fitted with stirrer.

[0195] In an embodiment of the present disclosure, the predetermined weight ratio of the graft copolymer emulsion to the functional paste is 20:80 to 80:20. In an exemplary embodiment of the present disclosure, the predetermined weight ratio of the graft copolymer emulsion to the functional paste is 80:20. In another exemplary embodiment of the present disclosure, the predetermined weight ratio of the graft copolymer emulsion to the functional paste is 60:40. In still another exemplary embodiment of the present disclosure, the predetermined weight ratio of the graft copolymer emulsion to the functional paste is 40:60. In yet another exemplary embodiment of the present disclosure, the predetermined weight ratio of the graft copolymer emulsion and the functional paste is 20:80.

[0196] In an exemplary embodiment of the present disclosure, the mixing is carried out at 300 rpm for 30minutes to obtain the paint formulation.

[0197] Figure 1 illustrates a schematic process of synthesis of a graft copolymer from a plurality of monomers, in accordance with an embodiment of the present disclosure.

[0198] The grafted copolymer emulsion prepared synergizes functional properties of a plurality of monomers achieving all the desired performance properties. The grafted copolymer is synthesized with emulsion polymerization process using water as solvent. The process is devoid of any organic solvents, coalescent agents or any other volatile element which can cause environmental issues. The process is a two stage process to attain a particular morphology of the grafted copolymer. The polymer chains are grafted on each other in such a way that a branched structure is created. The particular branched structure is responsible for creating a strong grafted copolymer resulting in the enhancement of performance properties at low film thickness in aggressive climatic conditions.

[0199] The grafted copolymer emulsion prepared in accordance with the present invention, makes its operational friendly. The paint formulation comprising the grafted copolymer emulsion is a single pack, ready to use composition and when applied on a surface dries quickly at room temperature. These features save time, manpower, energy requirements and cost of operation. The graft copolymer emulsion can be applied with a brush, roller, airless and air assisted spray gun and can be applied on a number of substrates such as steel, concrete, wood, paper, gypsum and can give surface finishes like smooth, textured, matt, semi glossy, and glossy.

[0200] In an embodiment of the present disclosure, a film thickness of the dried grafted copolymer coating is in a range of 80 microns to 100 microns.

[0201] In an embodiment of the present disclosure, the graft copolymer emulsion in accordance with the present invention is used for coating surfaces in industries related to infrastructure, oil and gas, marine and shipping, automobiles, power, steel and cement.

[0202] In another embodiment of the present disclosure, the paint formulation comprising the graft copolymer emulsion prepared in accordance with the present invention is used for coating surfaces in industries related to infrastructure, oil and gas, marine and shipping, automobiles, power, steel and cement.

[0203] All the resources used are non-toxic, Restriction of Hazardous Substances (ROHS) directive compliant and safe during coating and post coating. The coating does not release VOCs, has no smell or fumes and therefore, the process of application of the prepared coating composition is environment friendly.

[0204] The paint formulation prepared in accordance with the present disclosure can be used for coating various surfaces for various applications such as anti-bacterial decorative coating, heat insulation coating to reduce heat transfer to keep interiors cool.

[0205] Traditionally, coalescing agents are incorporated into paint formulations or coating composition. However, their use presents several drawbacks, including the emission of harmful volatile organic compounds (VOCs), unpleasant odors, potential irritation to the skin, eyes, or respiratory system, high cost, and negative impacts on film hardness, water resistance, and appearance. The coating composition described in the present disclosure is free from coalescing agents and, as a result, avoids these associated disadvantages.

[0206] The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.

[0207] The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial / commercial scale and the results obtained can be extrapolated to industrial scale.

[0208] EXPERIMENTAL DETAILS

[0209] Experiment 1: Process for the preparation of the Paint formulation in accordance with the present disclosure

[0210] Example 1: Process for the preparation of the graft copolymer emulsion (without crosslinking monomer) in accordance with the present disclosure.

[0211] Step 1:

[0212] The graft copolymer emulsion was prepared by using emulsion polymerization technique. A three neck round bottom flask fitted with stirrer and condenser was used which was placed in hot water bath having electric heating system and inlet / outlet opening for heating and cooling reactants during polymerization process.

[0213] In the round bottom flask (reactor), 470 grams of water, 5 grams liquid ammonia solution (buffer), 7.6 grams of sodium lauryl sulphate (emulsifier) and 1.9 grams of ethoxylated alkyl alcohol (emulsifier) (total 9.5 grams of an emulsifier) and 1 gram of potassium persulfate (a first portion of an initiator) was mixed at 25 °C at a stirring speed of 100 rpm (first stirring speed) for 20 minutes to obtain a first mixture. The so obtained first mixture was heated to raise the temperature to 70 °C under constant stirring at 130 rpm (second predetermined stirring speed), followed by adding 130 grams of methyl methacrylate (MMA-first hard segment monomer) and 0.6 grams potassium persulfate (20% solution in water) (a second portion of the initiator) at 200 grams / minute (a feeding rate of first hard segment and second portion of the initiator) and pre-polymerized to obtain a first polymer.

[0214] 100 grams of butyl acrylate (BAM) (a first soft segment monomer) was added with a feeding rate of 200 grams / minute and the reaction was carried out for 15 minutes (a first predetermined time period). This is followed by addition of 75 grams of butyl methacrylate (a second hard segment monomer) at a feeding rate of 200grams / minute and the reaction was carried out for 15 minutes (a first predetermined time period). This was followed by addition of 85 grams of ethyl hexyl acrylate (EHA) (a second soft segment monomer) at a feeding rate of 200 grams / minute and the reaction was carried out for 15 minutes (a first predetermined time period), followed by 40 grams of styrene (a third hard segment monomer) at a feeding rate of 200 grams / minute and the reaction was carried out for 15 minutes (a first predetermined time period). The addition of the monomers was carried out one after the other at 130 rpm to obtain a second polymer.

[0215] 15 grams of itaconic acid (a bio-based monomer) was added to the second polymer at a feeding rate of 200 grams / minute and the reaction was carried out for 15 minutes (a second predetermined time period) to obtain a third polymer.

[0216] 2 grams of maleic anhydride (a first reinforcing monomer) was added in the flask under constant stirring at a feeding rate of 200 grams / minute for 15 minutes, followed by adding 15 grams of acrylic acid (a second reinforcing monomer) under constant stirring at a feeding rate of 200 grams / minute for 15 minutes. The reaction was maintained at 85 °C (a first predetermined temperature) by supplying cold water in the bath and the reaction was carried out for 3 hours (a third predetermined time period) to obtain a graft copolymer emulsion.

[0217] The so obtained graft copolymer emulsion was cooled to 40°C (a second predetermined temperature), followed by decanting the graft copolymer emulsion from the reactor in a vessel to obtain the isolated graft copolymer emulsion.

[0218] Example 2: Process for the preparation of the graft copolymer emulsion (with crosslinking monomer) in accordance with the present disclosure. The graft copolymer emulsion of Example 2 was prepared by using the process step provided in Example 1 except with the addition of 45 grams of acetoacetoxy ethyl methacrylate (AAEM-a crosslinking monomer) after the addition of ethyl hexyl acrylate (EHA) (a second soft segment monomer) at a feeding rate of 200 grams / minute and the reaction was carried out for 15 minutes.

[0219] The predetermined amounts of the specific ingredients of the graft copolymer emulsion are as given in Table 1.

[0220] Table 1: Composition of the graft copolymer emulsion

[0221] Step 2: Process for the preparation of the functional paste in accordance with the present disclosure

[0222] Initially, wet grinding of fillers, extenders and pigments was carried out separately in a vertical sand mill using ceramic balls as a grinding medium. Diameter of the ceramic balls was 2 mm. The vertical mill was fitted with stirrer.

[0223] 200 grams of water and 40 grams of sodium polyacrylate (a dispersing agent) was added in the mill pot at 1440 rpm at 27 °C for 15 minutes to obtain a mixture. 400 grams of titanium dioxide (a pigment) was added under stirring for 20 minutes, followed by adding 120 grams of a mixture of silica, china clay, mica and talc in equal proportion (a filler) and 60 grams of barium sulphate (an extender) under stirring for 20 minutes and stirring was continued for 3 hours at 25 °C to obtain the functional paste.

[0224] The predetermined amounts of the specific ingredients of the functional paste are as given in Table 2.

[0225] Table 2: Composition of the functional paste Step 3: Process for the preparation of the paint formulation in accordance with the present disclosure

[0226] The paint formulation was prepared in a metal tank fitted with stirrer.

[0227] General procedure: The so obtained graft copolymer emulsion (prepared in step 1) and the functional paste (prepared in step 2) was mixed in a mass ratio of 80:20 at 300 rpm for 45 minutes to obtain the paint formulation (in the form of a homogenous mixture).

[0228] The following Table 3 shows the examples of paint formulation prepared by using various mass ratios of the graft copolymer emulsion and the functional paste in accordance with the present disclosure.

[0229] Table 3: Examples of the paint formulation in accordance with the present disclosure

[0230] The Examples El to E4 (without cross linking monomer) and E5 to E8 (with cross linking monomer) in accordance with the present disclosure were further tested for the performance.

[0231] For the sake of brevity, multiple number of experiments are not included in the specification. However, the other ingredients having similar functionality can be used in the preparation of the paint formulation of the present disclosure and the paint formulation will give similar results.

[0232] Experiment 2: Performance study of the paint formulation (El to E8) prepared in accordance with the present disclosure

[0233] The so obtained paint formulation in the Experiment 1 was tested by applying the paint formulation on metal panels of dimensions- a thickness in the range of 0.5 mm to 2 mm, a length in the range of 100 mm to 200 mm and a width in the range of 50 mm to 100 mm. The coated panels were conditioned for 7 days before performing the American Society for Testing and Materials (ASTM) tests. The conditioned panels were subjected to various performance tests as below.

[0234] (1) Study of scratch hardness of the coating of the paint formulation on the panel in accordance with the present disclosure

[0235] Scratch hardness of the coating was tested by using ASTM D7027. ASTM D7027 is the Standard Test Method for Evaluation of Scratch Resistance of Polymeric Coatings and Plastics Using an Instrumented Scratch Machine. It’s used to quantitatively assess scratch resistance by applying a progressively increasing or constant load through a stylus across a material surface. Figure 2 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on scratch hardness properties of the paint formulation in accordance with the present disclosure. Table 4 summarizes the results of scratch hardness for El to E 8 examples.

[0236] Table 4- Scratch hardness results.

[0237] From Table 4, it is clearly seen that as the proportion of the graft copolymer emulsion (resin) decreases and the functional paste increases, the scratch hardness decreases, indicating that the graft copolymer emulsion contributes significantly to the mechanical strength and hardness of the paint coating. Functional paste appears to dilute or soften the structure, reducing scratch resistance. The mass ratio of 80:20 (graft copolymer emulsion: functional paste) provides the highest scratch resistance.

[0238] (2) Study of flexibility of the coating of the paint formulation on the panel in accordance with the present disclosure Flexibility property of the paint coating was assessed. Figure 3 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on flexibility properties of the paint formulation in accordance with the present disclosure. Table 5 summarizes results of the flexibility study

[0239] Table 5: Flexibility properties

[0240] From Table 5, it is observed that as the functional paste content increases, the flexibility value (in mm) increases, indicating a more flexible coating.

[0241] Lower values represent high flexibility (less rigid), and higher values represent lower flexibility (more rigid). Higher graft copolymer emulsion content (80:20 and 60:40) gives higher flexibility values (3 mm), meaning the coating is flexible.

[0242] (3) Study of Adhesion property of the coating of the paint formulation on the panel in accordance with the present disclosure

[0243] Adhesion property of the paint coating was tested as per ASTM D-3359. The ASTM D3359 test is a standard method for measuring adhesion of coatings (like paints and varnishes) to substrates using a tape test. It’s widely used because it’s quick, simple, and cost-effective, though it is semi-quantitative. Table 6 summarizes the results of the adhesion test. Figure 4 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on adhesion properties of the paint formulation in accordance with the present disclosure.

[0244] Table 6: Adhesion test results

[0245] From Table 6, it is noted that the adhesion is highest at the 60:40 ratio, indicating optimal bonding at this balance of resin (graft copolymer emulsion) and functional paste. As the functional paste content increases beyond 40%, adhesion significantly decreases. The lowest adhesion occurs at 20:80 (value of 1), suggesting poor bonding strength. 60:40 ratio offers the best adhesion performance, likely due to a balanced interaction between flow, wetting, and cohesive strength. High graft copolymer emulsion (80:20) also gives good adhesion (value 5).

[0246] (4) Study of Salt spray resistance of the coating of the paint formulation on the panel in accordance with the present disclosure Salt spray resistance of the coating was performed as per ASTM BS-117 method. The

[0247] ASTM Bl 17 test (often referred to as the salt spray test) is the standard method for assessing the corrosion resistance of coated or uncoated metallic materials by exposing them to a controlled salt fog environment. Figure 5 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on salt spray resistant properties of the paint formulation in accordance with the present disclosure. Table 7 enlists the results of the test.

[0248] Table 7: Salt spray resistance results From Table 7, it is observed that high graft copolymer emulsion: functional paste ratios i.e. 80:20 and 60:40 showed 1000 hours of protection from corrosion, indicating strong corrosion resistance.

[0249] (5) Water immersion test of the coating of the paint formulation on the panel in accordance with the present disclosure

[0250] Water immersion test was performed on the paint coating as per ASTM D870. This test determines how well a coating withstands continuous exposure to water looking for signs of blistering, discoloration, softening, loss of adhesion, or other deterioration.

[0251] Figure 6 illustrates a graphical representation showing the effect of a mass ratio variation of a graft copolymer emulsion to a functional paste in a paint formulation on water resistant properties of the paint formulation in accordance with the present disclosure. Table 8 represents the results of the water immersion test.

[0252] Table 8: water resistant properties

[0253] From Table 8, it is observed that the table represents the water resistance performance of paint formulations based on different graft copolymer emulsion-to-functional paste ratios, measured in days of resistance under water immersion before failure (e.g., blistering, softening, or delamination). High graft copolymer emulsion: functional paste ratios (80:20 and 60:40) show excellent water resistance, maintaining integrity for 7 days, indicating a strong, continuous film that resists water penetration and degradation.

[0254] (6) Heat insulation property of the coating of the paint formulation on the panel in accordance with the present disclosure Heat insulation property (by way reflectivity of IR rays) of the panel coated with the paint formulation of the present disclosure.

[0255] Figure 7 illustrates a graphical representation showing the effect of the paint formulation of the present disclosure on heat insulation property by varying a mass ratio of a graft copolymer emulsion to a functional paste.

[0256] It is observed that the paint formulation provides a heat reflective coating which reflects a large portion of solar radiation particularly, in the infrared (IR) and visible spectra.

[0257] The paint formulation reflects incoming solar radiation particularly IR rays that carry most of the heat and emits absorbed heat in the mid-infrared range which helps to cool the surface through radiative cooling. Therefore, the less heat is absorbed by the coated surface thereby keeping it cooler.

[0258] Table 8 represents the results of the heat insulation property (by way reflectivity of IR rays on the coated and uncoated surfaces)

[0259] Table 8: Heat insulation property results (°C)

[0260] From Table 8 and Figure 7, it is observed that the paint formulation demonstrated excellent heat insulation and IR reflective properties, capable of reducing surface temperatures by up to 35 OC compared to the uncoated panels. This performance allows the paint formulation suitable for energy-efficient building surfaces, industrial tanks and thermal management panels.

[0261] Further, it is seen that lower ratio of graft copolymer emulsion: functional paste (i.e. 40:60 and 20:80) gives better heat insulation property, however it does not impart desired results in terms of other properties such as salt spray resistance, adhesion and flexibility. Therefore, it is evident that the ratio 60:40 of the graft copolymer emulsion: functional paste imparts all desired properties (such as better heat insulation property, better salt spray resistance, better adhesion and flexibility).

[0262] Following Table 9 summarizes the performance test carried out for the paint formulation coated panels, ASTM test Numbers and the results of the tests. Table 9: Performance test results for the paint formulation coated panels

[0263] From Table 9, it is observed that the paint formulation of the present disclosure shows all the desired properties as per ASTM standards.

[0264] Experiment 3: Comparison of the paint formulation comprising graft copolymer emulsion of the present disclosure and conventional coating system and water borne coatings

[0265] The properties of the paint formulation comprising the graft copolymer emulsion of the present disclosure was compared with the conventional coating system and water borne coating system. The observations are summarized in following Table 10 and Table 11.

[0266] Table 10: Comparison of properties of conventional coating system and the paint formulation comprising the graft copolymer emulsion of the present disclosure

[0267] Table 11: Comparison of properties of conventional water borne coating system and the paint formulation comprising the graft copolymer emulsion of the present disclosure

[0268] It is observed from Table 10 and Table 11 that the paint formulation comprising the graft copolymer emulsion in accordance with the present disclosure is found to have desired properties.

[0269] TECHNICAL ADVANCEMENTS

[0270] The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of;

[0271] -a paint formulation that: is a single pack, ready to use formulation with no need of hardener and catalyst; has excellent resistance to corrosion; • has excellent heat insulation properties;

[0272] • has resistance to UV radiations, moisture, scratches and chemicals;

[0273] • has excellent flexibility and good adhesion properties to all substrates;

[0274] • offers quick drying properties at room temperature;

[0275] • does not require primer application and can be directly applied to various substrates after adequate cleaning;

[0276] • can be applied with conventional application tools such as brush, roller, air assisted spray, airless spray, dip and flow technique; and

[0277] • has ease of application;

[0278] - a graft copolymer emulsion that has zero VOC, is water based, green and sustainable; and a process for preparation of paint formulation that is simple, efficient, economical and environment friendly.

[0279] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0280] The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.

[0281] Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0282] The numerical values given for various physical parameters, dimensions, and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions, and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.

[0283] While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

Claims

CLAIMS:

1. A paint formulation comprising:• a graft copolymer emulsion; and• a functional paste, wherein a weight ratio of said graft copolymer emulsion to said functional paste is in the range of 20:80 to 80:20.

2. The paint formulation as claimed in claim 1, wherein said graft copolymer emulsion is a reaction product of:• at least two monomers;• an initiator;• a buffer;• at least one emulsifier; and• water, wherein said monomers are selected from the group consisting of hard segment monomers, soft segment monomers, reinforcing monomers, cross linking monomers and bio-based monomers.

3. The paint formulation as claimed in claim 2, wherein• said monomers are present in an amount in the range of 15 mass% to 70 mass%;• said initiator is present in an amount in the range of 0.1 mass% to 2 mass%;• said buffer is present in an amount in the range of 0.1 mass% to 2 mass%;• said emulsifier is present in an amount in the range of 0.5 mass% to 5 mass%; and• water is present in an amount in the range of 30 mass% to 50 mass%, wherein said mass% of each ingredient is with respect to the total mass of said graft copolymer emulsion.

4. The paint formulation as claimed in claim 2, wherein• said hard segment monomer is at least one selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene;• said soft segment monomer is at least one selected from the group consisting of butyl acrylate monomer (BAM), ethyl acrylate monomer (EAM) and ethyl hexyl acrylate monomer (EHAM);• said reinforcing monomer is at least one selected from the group consisting of maleic anhydride, acrylic acid, and methacrylic acid;• said cross linking monomer is at least one selected from the group consisting of trifunctional monomers, acetoacetoxy ethyl methacrylate and trimethylol propane triacrylate; and• said bio-based monomer is at least one selected from the group consisting of itaconic acid, vegetable oil, lignin derivatives, terpenes, proteins and carbohydrates.

5. The paint formulation as claimed in claim 2, wherein• said initiator is at least one selected from potassium persulfate and 2,2'- azobisisobutyronitrile;• said buffer is at least one selected from the group consisting of liquid ammonia solution, sodium carbonate and sodium hydrogen sulphate; and• said emulsifier is a combination of an anionic emulsifier and a non-ionic emulsifier, wherein said anionic emulsifier is at least one selected from the group consisting of fatty acid, sodium lauryl sulfate and alpha-olefin sulfonate; and said non-ionic emulsifier is at least one selected from the group consisting of phosphate, polyamines, ethoxylated alkyl alcohol, amino alcohols and organic polyacid alkali salts.

6. The paint formulation as claimed in claim 2, wherein a mass ratio of said hard segment monomer to said soft segment monomer in said monomers is in the range of l:9 to 9: l.

7. The paint formulation as claimed in claim 1, wherein said functional paste comprises:• 10 mass% to 30 mass% of at least one filler;• 5 mass% to 20 mass% of at least one extender;20 mass% to 70 mass% of a pigment;1 mass% to 5 mass% of a dispersing agent; and20 mass% to 80 mass% of water, wherein said mass% of each ingredient is with respect to the total mass of said functional paste.

8. The paint formulation as claimed in claim 7, wherein• said filler is selected from the group consisting of silica, china clay, mica, talc and a combination thereof;• said extender is at least one selected from the group consisting of zinc phosphate, barium sulphate and ceramic;• said pigment is at least one selected from the group consisting of titanium dioxide, utox pigment, iron oxide, yellow oxide and chromium orange; and• said dispersing agent is at least one selected from the group consisting of an oil based dispersant, a silicone based dispersant, sodium polyacrylate, polyglycol ether, ethoxylated alkyl phenol and ethoxylate and diester of alcohol acid.

9. A process for the preparation of a paint formulation, said process comprising the following steps:(A) preparing a graft copolymer emulsion by: i. mixing predetermined amounts of water, a buffer, an emulsifier and a first portion of an initiator in a reactor at a temperature in the range of 20 °C to 40 °C at a first predetermined stirring speed for a time period in the range of 10 minutes to 40 minutes to obtain a first mixture; ii. heating said first mixture to a temperature in the range of 50 °C to 80 °C under stirring at a second predetermined stirring speed, followed by adding predetermined amounts of a first hard segment monomer and a second portion of said initiator at a predetermined feed rate and pre-polymerizing to obtain a first polymer;iii. sequentially mixing predetermined amounts of a first soft segment monomer, a second hard segment monomer, a second soft segment monomer, optionally a cross linking monomer and a third hard segment monomer to said first polymer at said predetermined feed rate under stirring for a first predetermined time period to obtain a second polymer; iv. adding a predetermined amount of a bio-based monomer to said second polymer at said predetermined feed rate under stirring for a second predetermined time period to obtain a third polymer; and v. sequentially mixing predetermined amounts of a first reinforcing monomer and a second reinforcing monomer to said third polymer under stirring at said predetermined feed rate and maintaining the reaction at a first predetermined temperature for a third predetermined time period followed by cooling to a second predetermined temperature to obtain said graft copolymer emulsion;.(B) separately preparing a functional paste by: a. mixing predetermined amounts of water and a dispersing agent under stirring at a speed in the range of 1200 rpm to 1600 rpm at a temperature in the range of 20 °C to 40 °C for a time period in the range of 10 minutes to 30 minutes to obtain a mixture; b. adding a predetermined amount of a pigment to said mixture under stirring for a time period in the range of 10 minutes to 30 minutes, followed by adding predetermined amounts of filler and an extender under stirring for a time period in the range of 10 minutes to 30 minutes and continuing stirring for a time period in the range of 2 hours to 5 hours at a temperature in the range of 20 °C to 40 °C to obtain the functional paste; and c. mixing said graft copolymer emulsion (prepared in Step A) and said functional paste (prepared in step B) in a predetermined weight ratio under stirring at a speed in the range of 100 rpm to 500 rpm for a timeperiod in the range of 20 minutes to 50 minutes to obtain said paint formulation.

10. The process as claimed in claim 9, wherein said at least one fdler, said at least one extender and said pigment are separately ground in a mill by using ceramic balls having diameter in the range of 1.5 mm to 4 mm to obtain ground particles of said filler, said extender and said pigment.

11. The process as claimed in claim 9, wherein• water in said step (i) is present in an amount in the range of 30 mass% to 50 mass%;• said buffer is present in an amount in the range of 0.1 mass% to 2 mass%;• said emulsifier is present in an amount in the range of 0.5 mass% to 5 mass%;• said first portion of said initiator is present in an amount in the range of 0.01 mass% to 1 mass%;• said first hard segment monomer is present in an amount in the range of 5 mass% to 20 mass%;• said second portion of said initiator is present in an amount in the range of 0.01 mass% to 1 mass%;• said cross-linking monomer is present in an amount in the range of 5 mass% to 10 mass%;• said second hard segment monomer is present in an amount in the range of 5 mass% to 15 mass%;• said third hard segment monomer is present in an amount in the range of 1 mass% to 10 mass%;• said first soft segment monomer is present in an amount in the range of 5 mass% to 15 mass%;• said second soft segment monomer is present in an amount in the range of 5 mass% to 15 mass%;• said bio-based monomer is present in an amount in the range of 0.5 mass% to 3 mass%;• said first reinforcing monomer is present in an amount in the range of 0.05 mass% to 2 mass%; and• said second reinforcing monomer is present in an amount in the range of 0.5 mass% to 3 mass%, wherein said mass% of each ingredient is with respect to the total mass of said graft copolymer emulsion.

12. The process as claimed in claim 9, wherein• said first hard segment monomer, said second hard segment monomer and said third hard segment monomer are independently at least one selected from the group consisting of methyl methacrylate (MMA), butyl methacrylate (BMA), vinyl acetate monomer (VAM) and styrene;• said first soft segment monomer and said second soft segment monomer are independently at least one selected from the group consisting of butyl acrylate monomer (BAM), ethyl acrylate monomer (EAM) and ethyl hexyl acrylate monomer (EHAM);• said first reinforcing monomer and said second reinforcing monomer are independently at least one selected from the group consisting of maleic anhydride, acrylic acid, and methacrylic acid;• said cross linking monomer is selected from the group consisting of trifunctional monomers, acetoacetoxy ethyl methacrylate and trimethylol propane triacrylate;• said bio-based monomer is selected from the group consisting of itaconic acid, vegetable oil, lignin derivatives, terpenes, proteins and carbohydrates;• said initiator is selected from potassium persulfate and 2,2'- azobisisobutyronitrile ;• said buffer is selected from the group consisting of liquid ammonia solution, sodium carbonate and sodium hydrogen sulphate; and• said emulsifier is a combination of an anionic emulsifier and a non-ionic emulsifier, wherein said anionic emulsifier is at least one selected from the group consisting of fatty acid, sodium lauryl sulfate and alpha-olefin sulfonate; and said non-ionic emulsifier is at least one selected from the groupconsisting of phosphate, polyamines, ethoxylated alkyl alcohol, amino alcohols and organic polyacid alkali salts.

13. The process as claimed in claim 9, wherein• said dispersing agent is present in an amount in the range of 1 mass% to 5 mass%;• said pigment is present in an amount in the range of 20 mass% to 70 mass%;• said fdler is present in an amount in the range of 10 mass% to 30 mass%;• said extender is present in an amount in the range of 5 mass% to 20 mass%;• water is present in an amount in the range of 20 mass% to 80 mass%, wherein mass% of each ingredient is with respect to the total mass of said functional paste.

14. The process as claimed in claim 9, wherein• said dispersing agent is selected from the group consisting of an oil based dispersant, a silicone based dispersant, sodium polyacrylate, polyglycol ether, ethoxylated alkyl alcohol, ethoxylated alkyl phenol and ethoxylate and diester of alcohol acid;• said pigment is selected from the group consisting of titanium dioxide, utox pigment, iron oxide, yellow oxide and chromium orange;• said filler is selected from the group consisting of silica, china clay, mica and talc and a combination thereof; and• said extender is selected from the group consisting of zinc phosphate, barium sulphates and ceramic.

15. The process as claimed in claim 9, wherein• said first predetermined stirring speed is in the range of 50 rpm to 150 rpm;• said second predetermined stirring speed is in the range of 50 rpm to 150 rpm;• said first predetermined temperature is in the range of 70 °C to 95 °C;• the second predetermined temperature is in the range of 30 °C to 50 °C;• said first predetermined time period is in the range of 15 minutes to 60 minutes;• said second predetermined time period is in the range of 5 minutes to 20 minutes;• said third predetermined time period is in the range of 2 hours to 5 hours; and• said predetermined feed rate is in the range of 100 grams per minute to 300 grams per minute .

16. The process as claimed in claim 9, wherein said predetermined weight ratio of said graft copolymer emulsion to said functional paste is in the range of 20:80 to 80:20.

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