DESC:FIELD
The present disclosure relates to a coating composition and a process for its preparation.
DEFINITIONS
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.
Dirt pickup resistance (DPUR): The term “Dirt pickup resistance (DPUR)” refers to the ability of coating (e.g., paint) to resist dirt in exposure to natural environments. Though it is named “dirt pickup”, it is not defined in terms of the amount of dirt accumulated on a surface, but in terms of the color change of a surface before and after a period of exposure.
CIELAB color space: The term “CIELAB color space” also known as “L*a*b*” refers to a color space defined by the International Commission on Illumination (abbreviated CIE) in 1976. The CIELAB color space expresses the color as three values: L* for perceptual lightness and a* and b* for the four unique colors of human vision: red, green, blue and yellow.
Delta E value: The term “delta E” also known as “DE value” refers to the value that is used to evaluate color differences. The higher the Delta E (?E) value, the further away the color is from the true hue/colour, using CIELAB.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Exterior architectural coatings represent a significant percentage of the volume and value of the coating market. With increasing demands for latex exterior coating compositions and more stringent volatile organic content (VOC) restrictions, dirt pickup has become an area of attention for the coating industry. Compared to the solvent-borne coating compositions, the latex coating compositions and particularly those with low VOC content, tend to be more susceptible to dirt pickup on exterior surfaces.
Conventionally, the surface of the exterior wall coated with the coating composition leads to pores on the surface making the surface rough. To the rough coated surface, dirt gets easily adhered or picked up and gets ingressed in to the pores of the surface. These ingressed dirt particles cannot be dislodged from the surface easily and affects the appearance of the surface due to color change.
Dirt pickup resistance (DPUR) is an important performance attribute for exterior architectural coatings, especially in growing, highly populated markets that have poor air quality.
Consumer desire remains strong for the ideal exterior paint especially with low dirt pickup and long durability but, delivering the same poses a challenge for the manufacturers. Further, the paint industry uses compounds such as benzophenone to aid the dirt pick up resistance in the water based coating compositions, specifically water-based acrylic coatings. However, such coating composition face a major concern of VOC emission due to the use of organic compounds.
Therefore, there is felt a need to provide a coating composition and a process for its preparation that obviates the drawbacks mentioned hereinabove or at least provide an alternative solution.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows.
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.
Another object of the present disclosure is to provide a coating composition.
Still another object of the present disclosure is to provide a coating composition that has improved durability.
Yet another object of the present disclosure is to provide a coating composition that has dirt pick up resistance.
Still another object of the present disclosure is to provide a coating composition with anti-algal, and antifungal properties.
Yet another object of the present disclosure is to provide a coating composition with improved anti-damp performance.
Still another object of the present disclosure is to provide a process for the preparation of a coating composition.
Yet another object of the present disclosure is to provide a simple and environment friendly process for the preparation of a coating composition.
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.
SUMMARY
The present disclosure relates to a coating composition and a process for its preparation.
The present disclosure relates to a coating composition.
The coating composition comprises
· a homogenous blend of an emulsion in an amount in the range of 80 mass% to 99 mass%; and
· a surface modifier in an amount in the range of 1 mass% to 20 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
The surface modifier is in the form of a colloidal dispersion of silica particles in water and wherein an amount of the silica particles is in the range of 10 mass% to 30 mass% with respect to the total amount of the colloidal dispersion.
The silica particles have a particle size in the range of 7 nm to 20 nm.
The homogenous blend of an emulsion comprises:
· at least one binder in an amount in the range of 25 mass% to 35 mass%;
· at least one filler in an amount in the range of 5 mass% to 18 mass%;
· at least one biocide in an amount in the range of 0.5 mass% to 2 mass%;
· at least one pigment in an amount in the range of 15 mass% to 25 mass%;
· at least one preservative in an amount in the range of 1 mass% to 3 mass%;
· at least one opacifier in an amount in the range of 5 mass% to 15 mass%;
· at least one additive in an amount in the range of 1 mass% to 15 mass%; and
· water in an amount in the range of 3 mass% to 20 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In an embodiment of the present disclosure,
· the binder is acrylic based emulsion;
· the filler is selected from the group consisting of calcium carbonate, talc and dolomite;
· the biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, benzisothiazolinone, octylisothiazolinone, dichlorooctylisothiazolinone and butylisothiazolinone;
· the pigment is rutile titanium dioxide;
· the preservative is selected from the group consisting of benzimidazole carbamate, urea derivatives and zinc pyrithione based preservatives;
· the opacifier is polymeric opacifier; and
· the additive comprises a pH stabilizer, a sequestering agent, a defoamer, a wetting agent, a dispersing agent, a coalescing agent, and a thickener.
In an embodiment of the present disclosure,
· the pH stabilizer is a synergistic mixture of alkaline compounds with special organics;
· the sequestering agent is selected from sodium hexametaphosphate and potassium pyrophosphate;
· the defoamer is mineral oil defoamer;
· the wetting agent is selected from an ethoxylate and a polyether; the polyether is glycol ether.
· the dispersing agent is selected from ammonium polyacrylate and sodium polyacrylate;
· the coalescing agent is (3-hydroxy-2,2,4-trimethylpentyl)2-methylpropanoate; and
· the thickener is hydroxyethyl cellulose.
In an embodiment of the present disclosure,
· the pH stabilizer is present in an amount in the range of 0.1 mass% to 0.5 mass%;
· the sequestering agent is present in an amount in the range of 0.2 mass% to 0.6 mass%;
· the defoamer is present in an amount in the range of 0.3 mass% to 3 mass%;
· the wetting agent is present in an amount in the range of 0.2 mass% to 1 mass%;
· the dispersing agent is present in an amount in the range of 0.4 mass% to 3 mass%;
· the coalescing agent is present in an amount in the range of 0.5 mass% to 2.5 mass%; and
· the thickener is present in an amount in the range of 0.2 mass% to 1 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
The present disclosure further relates to a process for the preparation of a coating composition.
The process for the preparation of a coating composition comprises following steps:
i. mixing a predetermined amount of a first portion of water and a first portion of a biocide under stirring at a first predetermined speed at a first predetermined temperature for a first predetermined time period to obtain a first slurry;
ii. adding predetermined amounts of at least one pH stabilizer, at least one sequestering agent and a first portion of a defoamer in the first slurry under stirring at the first predetermined speed for a second predetermined time period followed by adding predetermined amounts of at least one wetting agent, a first portion of at least one dispersing agent, and a second portion of the defoamer under stirring at the first predetermined speed for a third predetermined time period to obtain a second slurry;
iii. increasing the stirring speed from the first predetermined speed to a second predetermined speed followed by adding a second portion of the biocide, predetermined amounts of at least one pigment, at least one filler and a second portion of water in the second slurry for a fourth predetermined time period to obtain a third slurry;
iv. adding a second portion of at least one dispersing agent, predetermined amounts of at least one coalescing agent, and at least one preservative in the third slurry under stirring by maintaining the second predetermined stirring speed for a fifth predetermined time period followed by adding a predetermined amount of a thickener and a third portion of water for a sixth predetermined time period to obtain an intermediate slurry;
v. adding a predetermined amount of at least one binder and a third portion of the defoamer in the intermediate slurry at a second predetermined temperature for a seventh predetermined time period under stirring at a third predetermined stirring speed to obtain a resultant slurry; and
vi. mixing predetermined amounts of at least one opacifier, a fourth portion of the defoamer and a surface modifier in the resultant slurry for an eighth predetermined time period to obtain the coating composition.
In an embodiment of the present disclosure,
• the binder is acrylic based emulsion;
• the filler is selected from the group consisting of calcium carbonate, talc and dolomite;
• the biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, benzisothiazolinone, octylisothiazolinone, dichlorooctylisothiazolinone and butylisothiazolinone;
• the pigment is rutile titanium dioxide;
• the preservative is selected from the group consisting of benzimidazole carbamate, urea derivatives and zinc pyrithione based preservatives;
• the opacifier is polymeric opacifier;
• the pH stabilizer is a synergistic mixture of alkaline compounds with special organics;
• the sequestering agent is selected from sodium hexametaphosphate and potassium pyrophosphate;
• the defoamer is mineral oil defoamer;
• the wetting agent is selected from an ethoxylate and a polyether; wherein the polyether is glycol ether;
• the dispersing agent is selected from ammonium polyacrylate and sodium polyacrylate;
• the coalescing agent is (3-hydroxy-2,2,4-trimethylpentyl)2-methylpropanoate; and
• the thickener is hydroxyethyl cellulose.
In an embodiment of the present disclosure,
· the binder is present in an amount in the range of 25 mass% to 35 mass%;
· the filler is present in an amount in the range of 5 mass% to 18 mass%;
· the biocide is present in an amount in the range of 0.5 mass% to 2 mass%;
· the pigment is present in an amount in the range of 15 mass% to 25 mass%;
· the preservative is present in an amount in the range of 1 mass% to 3 mass%;
· the opacifier is present in an amount in the range of 5 mass% to 15 mass%;
· the pH stabilizer is present in an amount in the range of 0.1 mass% to 0.5 mass%;
· the sequestering agent is present in an amount in the range of 0.2 mass% to 0.6 mass%;
· the defoamer is present in an amount in the range of 0.3 mass% to 3 mass%;
· the wetting agent is present in an amount in the range of 0.2 mass% to 1 mass%;
· the dispersing agent is present in an amount in the range of 0.4 mass% to 3 mass%;
· the coalescing agent is present in an amount in the range of 0.5 mass% to 2.5 mass%;
· the thickener is present in an amount in the range of 0.2 mass% to 1 mass%;
· the surface modifier is present in an amount in the range of 1 mass% to 20 mass%; and
· water is present in an amount in the range of 3 mass% to 20 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
The surface modifier is in the form of a colloidal dispersion of silica particles in water and wherein an amount of the silica particles is in the range of 10 mass% to 30 mass% with respect to the total amount of the colloidal dispersion.
The silica particles have a particle size in the range of 7 nm to 20 nm.
The first portion of the biocide is in the range of 25 mass% to 30 mass%; and the second portion of the biocide is in the range of 70 mass% to 75 mass%, wherein the mass% of each portion of the biocide is with respect to the total mass of the biocide.
The first portion of the defoamer is in the range of 45 mass% to 55 mass%; the second portion of the defoamer is in the range of 15 mass% to 20 mass%; the third portion of the defoamer is in the range of 15 mass% to 20 mass%; and the fourth portion of the defoamer is in the range of 15 mass% to 20 mass%, wherein the mass% of each portion of the defoamer is with respect to the total mass of the defoamer.
The first portion of the dispersing agent is in the range of 45 mass% to 55 mass%; and the second portion of the dispersing agent is in the range of 45 mass% to 55 mass%, wherein the mass% of each portion of the dispersing agent is with respect to the total mass of the dispersing agent.
The first portion of water is in the range of 80 mass% to 85 mass%; the second portion of water is in the range of 5 mass% to 15 mass%; and the third portion of water is in the range of 5 mass% to 15 mass%, wherein the mass% of each portion of water is with respect to the total mass of water.
The first predetermined stirring speed is in the range of 10 m/sec to 12 m/sec; the second predetermined stirring speed is in the range of 20 m/sec to 22 m/sec; and the third predetermined stirring speed is in the range of 10 m/sec to 12 m/sec.
The first predetermined temperature is in the range of 35 oC to 45 oC; and the second predetermined temperature is in the range of 35 oC to 45 oC.
The first predetermined time period is in the range of 5 minutes to 10 minutes; the second predetermined time period is in the range of 5 minutes to 10 minutes; the third predetermined time period is in the range of 5 minutes to 10 minutes; the fourth predetermined time period is in the range of 5 minutes to 10 minutes; the fifth predetermined time period is in the range of 10 minutes to 15 minutes; the sixth predetermined time period is in the range of 15 minutes to 45 minutes; the seventh predetermined time period is in the range of 15 minutes to 25 minutes; and the eighth predetermined time period is in the range of 5 minutes to 15 minutes.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a schematic representation of (A) a coating composition without a surface modifier (comparative coating composition) and (B) a coating composition with a surface modifier prepared in accordance with the present disclosure, wherein “p” and “q” illustrate the particles of the extender/pigment/other emulsion particles; and “z” illustrates the particles of the colloidal nanosilica; and
Figure 2 illustrates images of demonstration of Dirt Pick Up Resistance (DPUR) property of the coating composition of the present disclosure (Examples 1 to 3) as compared to the coating composition prepared in comparative example 1 coated on test panels.
DETAILED DESCRIPTION
The present disclosure relates to a coating composition and a process for its preparation.
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
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.
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.
As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
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.
Consumers strongly demand ideal exterior paints with low dirt pickup and long durability, but manufacturers face challenges in meeting these expectations. The paint industry often relies on compounds like benzophenone to improve dirt pickup resistance in water-based acrylic coatings; however, these organic additives contribute to significant VOC emissions, raising environmental and regulatory concerns.
The present disclosure provides a coating composition and a process for its preparation.
In a first aspect, the present disclosure provides to a coating composition.
The coating composition comprises:
· a homogenous blend of an emulsion in an amount in the range of 80 mass% to 99 mass%; and
· a surface modifier in an amount in the range of 1 mass% to 20 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In an exemplary embodiment of the present disclosure, the coating composition comprises 82 mass% of the homogenous blend of an emulsion with respect to the total mass of the coating composition and 18 mass% of the surface modifier with respect to the total mass of the coating composition.
The surface modifier is in the form of a colloidal dispersion of silica particles in water and wherein an amount of the silica particles is in the range of 10 mass% to 30 mass% with respect to the total amount of the colloidal dispersion.
The silica particles have a particle size in the range of 7 nm to 20 nm.
In accordance with the present disclosure, the surface modifier gets uniformly aligned throughout the film formed by the coating composition and provides surface enrichment with the inert particles after drying. The addition of colloidal nanosilica leads to the smooth coated surface. This alignment of the surface modifier prevents the dirt/environmental dust from adhering and ingressing in the coated film obtained by applying the coating composition of the present disclosure. Hence, the dirt remains loosely adhered on the surface of the film and can be dislodged easily from the surface.
In an exemplary embodiment of the present disclosure, the surface modifier (KemoSil™ SiL-30MS) is an alkaline dispersion of anionic amorphous silica. The amorphous silica contains 30% solids by weight and characterised by high versatility as it contains silica particles that are relatively intermediate in size. The average particle size of the silica particles is in the range of 7 nm to 20 nm. The physical appearance of the dispersion is a clear liquid, slightly more viscous than water.
The amorphous silica particles are produced by polymerising silica nuclei from silicate solutions under alkaline conditions to form nanometer sized silica sols with high surface area. A charge is then induced on the silica nanoparticle surface that allows the silica particles to repel one another and form a stable dispersion or colloid. Thus, the colloidal silica is a dispersion of amorphous silicon dioxide (silica) particles in water.
In accordance with the present disclosure, a colloidal silica is prepared by using ion exchange of aqueous silicates.
The addition of surface modifier is advantageous due to the fact that they have appropriate particle size due to which they can get easily aligned in to at least some of the pores of the film formed by the coating composition and prevent dust or dirt particles entering in to the pores and forms smooth coating on the surface. The smooth coating formed on the surface after drying, aids in dislodging dirt particles easily.
By using the surface modifier, the coating composition of the present disclosure results in near-zero levels of VOC emissions, thereby reducing the environmental and health impact of the coating compositions.
The use of surface modifier in the coating composition of the present disclosure provides desired properties to the film without sacrificing other properties. The coating composition of the present disclosure has improved dirt pick up resistance, improved durability, provides anti-algal property, anti-fungal property and improved anti-damp properties.
The homogenous blend of an emulsion comprises:
· at least one binder in an amount in the range of 25 mass% to 35 mass%;
· at least one filler in an amount in the range of 5 mass% to 18 mass%;
· at least one biocide in an amount in the range of 0.5 mass% to 2 mass%;
· at least one pigment in an amount in the range of 15 mass% to 25 mass%;
· at least one preservative in an amount in the range of 1 mass% to 3 mass%;
· at least one opacifier in an amount in the range of 5 mass% to 15 mass%;
· at least one additive in an amount in the range of 1 mass% to 15 mass%; and
· water in an amount in the range of 3 mass% to 20 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In an exemplary embodiment of the present disclosure, the homogenous blend of an emulsion comprises:
· Acrylic based emulsion (binder) in an amount of 28 mass%;
· Talc (filler) in an amount of 6 mass% and calcium carbonate (CaCO3) (filler) in an amount of 5 mass%;
· Benzisothiazolinone (biocide) in an amount of 0.6 mass%;
· Rutile TiO2 (pigment) in an amount of 22 mass%;
· Benzimidazole carbamate (preservative) in an amount of 2 mass%;
· Ropaque™ Ultra-E opaque polymer (opacifier) in an amount of 10 mass%;
· additives in an amount of 4.8 mass%; and
· water in an amount of 3.6 mass%,
wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
The binder is acrylic based emulsion. The binder of the present disclosure forms a water-resistant film after drying of coating composition.
The filler is selected from the group consisting of calcium carbonate, talc and dolomite. In an exemplary embodiment of the present disclosure, the filler is talc and calcium carbonate. Filler is used in coating composition to reduce the cost of the coating composition. Further, filler helps to improve the application properties of the coating composition.
The biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, benzisothiazolinone, octylisothiazolinone, dichlorooctylisothiazolinone and butylisothiazolinone. In an exemplary embodiment of the present disclosure, the biocide is benzisothiazolinone. The biocide provides antimicrobial performance.
The pigment is rutile titanium dioxide. Titanium dioxide adds color or changes the appearance of a material by absorbing or scattering light.
The preservative is selected from the group consisting of benzimidazole carbamate, urea derivatives and zinc pyrithione based preservatives. In an exemplary embodiment of the present disclosure, the preservative is benzimidazole carbamate. The preservative extends the shelf life of the coating composition.
The opacifier is polymeric opacifier. In an exemplary embodiment of the present disclosure, the opacifier is Ropaque™ Ultra-E opaque polymer. The opacifier is added to the coating composition to make opaque or less transparent film.
The additive is at least one selected from the group consisting of a pH stabilizer, a sequestering agent, a defoamer, a wetting agent, a dispersing agent, a coalescing agent, and a thickener.
The pH stabilizer is a synergistic mixture of alkaline compounds with special organics (Kemox PHS). In an exemplary embodiment of the present disclosure, the pH stabilizer is Kemox PHS. The pH stabilizer stabilizes the coating composition.
The sequestering agent is selected from sodium hexametaphosphate and potassium pyrophosphate. In an exemplary embodiment of the present disclosure, the sequestering agent is sodium hexametaphosphate. The sequestering agent softens the water.
The defoamer is mineral oil defoamer. The defoamer reduces or eliminates foam in the coating composition.
The wetting agent is selected from an ethoxylate and a polyether, wherein the polyether is glycol ether. In an exemplary embodiment of the present disclosure, the wetting agent is glycol ether. The wetting agent promotes the spreading of the coating composition on a surface.
The dispersing agent is selected from ammonium polyacrylate and sodium polyacrylate. In an exemplary embodiment of the present disclosure, the dispersing agent is ammonium polyacrylate. The dispersing agent helps to separate particles in the coating composition and prevents them from clumping or settling.
The coalescing agent is (3-hydroxy-2,2,4-trimethylpentyl)2-methylpropanoate (Texanol). The coalescing agent facilitates the merging of dispersed particles, particularly during the drying or curing process.
The thickener is hydroxyethyl cellulose. The thickener increases the viscosity of the coating composition without substantially changing its other properties.
The pH stabilizer is present in an amount in the range of 0.1 mass% to 0.5 mass%; the sequestering agent is present in an amount in the range of 0.2 mass% to 0.6 mass%; the defoamer is present in an amount in the range of 0.3 mass% to 3 mass%; the wetting agent is present in an amount in the range of 0.2 mass% to 1 mass%; the dispersing agent is present in an amount in the range of 0.4 mass% to 3 mass%; the coalescing agent is present in an amount in the range of 0.5 mass% to 2.5 mass%; and the thickener is present in an amount in the range of 0.2 mass% to 1 mass%, wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In an exemplary embodiment of the present disclosure, the pH stabilizer is present in an amount of 0.3 mass%; the sequestering agent is present in an amount of 0.3 mass%; the defoamer is present in an amount of 0.5 mass%; the wetting agent is present in an amount of 0.7 mass%; the dispersing agent is present in an amount of 1.2 mass%; the coalescing agent is present in an amount of 1.4 mass%; and the thickener is present in an amount of 0.4 mass%, wherein the mass% of each ingredient is with respect to the total mass of the coating composition.
In a second aspect, the present disclosure relates to a process for the preparation of a coating composition.
The process for the preparation of a coating composition comprises the following steps:
i. mixing predetermined amounts of a first portion of water and a first portion of a biocide under stirring at a first predetermined speed at a first predetermined temperature for a first predetermined time period to obtain a first slurry;
ii. adding predetermined amounts of at least one pH stabilizer, at least one sequestering agent and a first portion of a defoamer in the first slurry under stirring at the first predetermined speed for a second predetermined time period followed by adding predetermined amounts of at least one wetting agent, a first portion of at least one dispersing agent, and a second portion of the defoamer under stirring at the first predetermined speed for a third predetermined time period to obtain a second slurry;
iii. increasing the stirring speed from the first predetermined speed to a second predetermined speed followed by adding a second portion of the biocide, predetermined amounts of at least one pigment, at least one filler and a second portion of water in the second slurry for a fourth predetermined time period to obtain a third slurry;
iv. adding a second portion of at least one dispersing agent, predetermined amounts of at least one coalescing agent, and at least one preservative in the third slurry under stirring by maintaining the second predetermined stirring speed for a fifth predetermined time period followed by adding a predetermined amount of a thickener and a third portion of water for a sixth predetermined time period to obtain an intermediate slurry;
v. adding a predetermined amount of at least one binder and a third portion of the defoamer in the intermediate slurry at a second predetermined temperature for a seventh predetermined time period under stirring at a third predetermined stirring speed to obtain a resultant slurry; and
vi. mixing predetermined amounts of at least one opacifier, a fourth portion of the defoamer and a surface modifier in the resultant slurry for an eighth predetermined time period to obtain the coating composition.
The process is described in detail.
In a first step, predetermined amounts of a first portion of water and a first portion of a biocide are mixed under stirring at a first predetermined speed at a first predetermined temperature for a first predetermined time period to obtain a first slurry.
The water is present in an amount in the range of 3 mass% to 20 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, water is present in an amount of 3.6 mass% with respect to the total mass of the coating composition.
The first portion of water is in the range of 80 mass% to 85 mass% with respect to the total mass of water. In an exemplary embodiment of the present disclosure, the first portion of water is 82 mass% with respect to the total mass of water.
The biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, benzisothiazolinone, octylisothiazolinone, dichlorooctylisothiazolinone and butylisothiazolinone. In an exemplary embodiment of the present disclosure, the biocide is benzisothiazolinone.
The biocide is present in an amount in the range of 0.5 mass% to 2 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the biocide is present in an amount of 0.6 mass% with respect to the total mass of the coating composition.
The first portion of the biocide is in the range of 25 mass% to 30 mass% with respect to the total mass of the biocide. In an exemplary embodiment of the present disclosure, the first portion of the biocide is 28 mass% with respect to the total mass of the biocide.
The first predetermined stirring speed is in the range of 10 m/sec to 12 m/sec. In an exemplary embodiment of the present disclosure, the first predetermined stirring speed is 11 m/sec.
The first predetermined temperature is in the range of 35 oC to 45 oC. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 40 oC.
The first predetermined time period is in the range of 5 minutes to 10 minutes. In an exemplary embodiment of the present disclosure, the first predetermined time period is 8 minutes.
In a second step, predetermined amounts of at least one pH stabilizer, at least one sequestering agent and a first portion of a defoamer are added in the first slurry under stirring at the first predetermined speed for a second predetermined time period followed by adding predetermined amounts of at least one wetting agent, a first portion of at least one dispersing agent, and a second portion of the defoamer under stirring at the first predetermined speed for a third predetermined time period to obtain a second slurry.
The pH stabilizer is a synergistic mixture of alkaline compounds with special organics (Kemox PHS). In an exemplary embodiment of the present disclosure, the pH stabilizer Kemox PHS.
The pH stabilizer is present in an amount in the range of 0.1 mass% to 0.5 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, pH stabilizer is present in an amount of 0.3 mass% with respect to the total mass of the coating composition.
The sequestering agent is selected from sodium hexametaphosphate and potassium pyrophosphate. In an exemplary embodiment of the present disclosure, the sequestering agent is sodium hexametaphosphate.
The sequestering agent is present in an amount in the range of 0.2 mass% to 0.6 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the sequestering agent is present in amount of 0.3 mass% with respect to the total mass of the coating composition.
The defoamer is mineral oil defoamer.
The defoamer is present in an amount in the range of 0.3 mass% to 3 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the defoamer is present in an amount of 0.5 mass% with respect to the total mass of the coating composition.
The first portion of the defoamer is in the range of 45 mass% to 55 mass% with respect to the total mass of the defoamer. In an exemplary embodiment of the present disclosure, the first portion of the defoamer is 49 mass% with respect to the total mass of the defoamer.
The second predetermined time period is in the range of 5 minutes to 10 minutes. In an exemplary embodiment of the present disclosure, the second predetermined time period is 8 minutes.
The wetting agent is selected from an ethoxylate and a polyether, wherein the polyether is glycol ether. In an exemplary embodiment of the present disclosure, the wetting agent is glycol ether.
The wetting agent is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the wetting agent is present in an amount of 0.7 mass% with respect to the total mass of the coating composition.
The dispersing agent is selected from ammonium polyacrylate and sodium polyacrylate. In an exemplary embodiment of the present disclosure, the dispersing agent is ammonium polyacrylate.
The dispersing agent is present in an amount in the range of 0.4 mass% to 3 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the dispersing agent is present in an amount of 1.2 mass% with respect to the total mass of the coating composition.
The first portion of the dispersing agent is in the range of 45 mass% to 55 mass% with respect to the total mass of the dispersing agent. In an exemplary embodiment of the present disclosure, the first portion of the dispersing agent is 50 mass% with respect to the total mass of the dispersing agent.
The second portion of the defoamer is in the range of 15 mass% to 20 mass% with respect to the total mass of the defoamer. In an exemplary embodiment of the present disclosure, the second portion of the defoamer is 17 mass% with respect to the total mass of the defoamer.
The third predetermined time period is in the range of 5 minutes to 10 minutes. In an exemplary embodiment of the present disclosure, the third predetermined time period is 8 minutes.
In a third step, the stirring speed is increased from the first predetermined speed to a second predetermined speed followed by adding a second portion of the biocide, predetermined amounts of at least one pigment, at least one filler and a second portion of water in the second slurry for a fourth predetermined time period to obtain a third slurry.
The second predetermined stirring speed is in the range of 20 m/sec to 22 m/sec. In an exemplary embodiment of the present disclosure, the second predetermined stirring speed is 21 m/sec.
The second portion of the biocide is in the range of 70 mass% to 75 mass% with respect to the total mass of the biocide. In an exemplary embodiment of the present disclosure, the second portion of the biocide is 72 mass% with respect to the total mass of the biocide.
The pigment is rutile titanium dioxide.
The pigment is present in an amount in the range of 15 mass% to 25 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the pigment is present in an amount of 22 mass% with respect to the total mass of the coating composition.
The filler is selected from the group consisting of calcium carbonate, talc and dolomite. In an exemplary embodiment of the present disclosure, the filler is talc and calcium carbonate.
The filler is present in an amount in the range of 5 mass% to 18 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, talc is present in an amount of 6 mass% and calcium carbonate is present in an amount of 5 mass% with respect to the total mass of the coating composition.
The second portion of the water is present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of water. In an exemplary embodiment of the present disclosure, the second portion of the water is 8 mass% with respect to the total mass of water.
The fourth predetermined time period is in the range of 5 minutes to 10 minutes. In an exemplary embodiment of the present disclosure, the fourth predetermined time period is 8 minutes.
In a fourth step, a second portion of at least one dispersing agent, predetermined amounts of at least one coalescing agent, and at least one preservative is added in the third slurry under stirring by maintaining the second predetermined stirring speed for a fifth predetermined time period followed by adding a predetermined amount of a thickener and a third portion of water for a sixth predetermined time period to obtain an intermediate slurry.
The second portion of the dispersing agent is in the range of 45 mass% to 55 mass% with respect to the total mass of the dispersing agent. In an exemplary embodiment of the present disclosure, the second portion of the dispersing agent is 50 mass% with respect to the total mass of the dispersing agent.
The coalescing agent is (3-hydroxy-2,2,4-trimethylpentyl)2-methylpropanoate (Texanol).
The coalescing agent is present in an amount in the range of 0.5 mass% to 2.5 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the coalescing agent is present in an amount of 1.4 mass% with respect to the total mass of the coating composition.
The preservative is selected from the group consisting of benzimidazole carbamate, urea derivatives and zinc pyrithione based preservatives. In an exemplary embodiment of the present disclosure, the preservative is benzimidazole carbamate.
The preservative is present in an amount in the range of 1 mass% to 3 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the preservative is present in an amount of 2 mass% with respect to the total mass of the coating composition.
The fifth predetermined time period is in the range of 10 minutes to 15 minutes. In an exemplary embodiment of the present disclosure, the fifth predetermined time period is 12 minutes.
The thickener is hydroxyethyl cellulose.
The thickener is present in an amount in the range of 0.2 mass% to 1 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the thickener is present in an amount of 0.4 mass% with respect to the total mass of the coating composition.
The third portion of water is in the range of 5 mass% to 15 mass% with respect to the total mass of water. In an exemplary embodiment of the present disclosure, the third portion of water is 10 mass% with respect to the total mass of water.
The sixth predetermined time period is in the range of 15 minutes to 45 minutes. In an exemplary embodiment of the present disclosure, the sixth predetermined time period is 30 minutes.
In a fifth step, a predetermined amount of at least one binder and a third portion of the defoamer are added in the intermediate slurry at a second predetermined temperature for a seventh predetermined time period under stirring at a third predetermined stirring speed to obtain a resultant slurry.
The binder is acrylic based emulsion.
The binder is present in an amount in the range of 25 mass% to 35 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the binder is present in an amount of 28 mass% with respect to the total mass of the coating composition.
The third portion of the defoamer is in the range of 15 mass% to 20 mass% with respect to the total mass of the defoamer. In an exemplary embodiment of the present disclosure, the third portion of the defoamer is 17 mass% with respect to the total mass of the defoamer.
The second predetermined temperature is in the range of 35 oC to 45 oC. In an exemplary embodiment of the present disclosure, the second predetermined temperature is 40 oC.
The seventh predetermined time period is in the range of 15 minutes to 25 minutes. In an exemplary embodiment of the present disclosure, the seventh predetermined time period is 20 minutes.
The third predetermined stirring speed is in the range of 10 m/sec to 12 m/sec. In an exemplary embodiment of the present disclosure, the third predetermined stirring speed is 11 m/sec.
In a sixth step, predetermined amounts of at least one opacifier, a fourth portion of the defoamer and a surface modifier are mixed in the resultant slurry for an eighth predetermined time period to obtain the coating composition.
The opacifier is polymeric opacifier. In an exemplary embodiment of the present disclosure, the opacifier is Ropaque™ Ultra-E opaque polymer.
The opacifier is present in an amount in the range of 5 mass% to 15 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure, the opacifier is present in an amount of 10 mass% with respect to the total mass of the coating composition.
The fourth portion of the defoamer is in the range of 15 mass% to 20 mass% with respect to the total mass of the defoamer. In an exemplary embodiment of the present disclosure, the fourth portion of the defoamer is 17 mass% with respect to the total mass of defoamer.
The surface modifier is in the form of a colloidal dispersion of silica particles in water and wherein an amount of the silica particles is in the range of 10 mass% to 30 mass% with respect to the total amount of the colloidal dispersion.
Colloidal nanosilica is an alkaline dispersion of anionic amorphous silica.
In an embodiment of the present disclosure, the particle size of the silica particles in the surface modifier is in the range of 7 nm to 20 nm.
The predetermined amount of the surface modifier is in the range of 1 mass% to 20 mass% with respect to the total mass of the coating composition. In an exemplary embodiment of the present disclosure the surface modifier is 18 mass% with respect to the total mass of the coating composition.
The eighth predetermined time period is in the range of 5 minutes to 15 minutes. In an exemplary embodiment of the present disclosure, the eighth predetermined time period is 10 minutes.
The coating composition of the present disclosure is used to obtain durable exterior coatings of high DPUR that maintain their attractiveness for longer periods of time and offer more sustainable coating solutions due to reduced consumption of coating ingredients and related waste generation.
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.
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.
EXPERIMENTAL DETAILS
Experiment 1: Process for the preparation of the coating composition in accordance with the present disclosure
General procedure:
Step (i): Predetermined amounts of a first portion of water and a first portion of a biocide were mixed under stirring at a speed in the range of 10 m/sec to 12 m/sec (first predetermined speed) at a temperature in the range of 35 oC to 45 oC (first predetermined temperature) for a time period in the range of 5 minutes to 10 minutes (first predetermined time period) to obtain a first slurry.
Step (ii): Predetermined amounts of at least one pH stabilizer, at least one sequestering agent and a first portion of a defoamer were added in the first slurry under stirring at the speed in the range of 10 m/sec to 12 m/sec (first predetermined speed) for a time period in the range of 5 minutes to 10 minutes (second predetermined time period) followed by adding predetermined amounts of at least one wetting agent, a first portion of at least one dispersing agent, and a second portion of the defoamer under stirring at the speed in the range of 10 m/sec to 12 m/sec (first predetermined speed) for a time period in the range of 5 minutes to 10 minutes (third predetermined time period) to obtain a second slurry.
Step (iii): The stirring speed was increased from the range of 10 m/sec to 12 m/sec (first predetermined speed) to a speed in the range of 20 m/sec to 22 m/sec (second predetermined speed) followed by adding a second portion of the biocide, predetermined amounts of at least one pigment, at least one filler and a second portion of water in the second slurry for a time period in the range of 5 minutes to 10 minutes (fourth predetermined time period) to obtain a third slurry.
Step (iv): A second portion of at least one dispersing agent, predetermined amounts of at least one coalescing agent, and at least one preservative were added in the third slurry under stirring by maintaining the stirring speed in the range of 20 m/sec to 22 m/sec (second predetermined stirring speed) for a time period in the range of 10 minutes to 15 minutes (fifth predetermined time period) followed by adding a predetermined amount of a thickener and a third portion of water for a time period in the range of 15 minutes to 45 minutes (sixth predetermined time period) to obtain an intermediate slurry.
Step (v): A predetermined amount of at least one binder and a third portion of the defoamer were added in the intermediate slurry at a temperature in the range of 35 oC to 45 oC (second predetermined temperature) for a time period in the range of 15 minutes to 25 minutes (seventh predetermined time period) under stirring at a stirring speed in the range of 10 m/sec to 12 m/sec (third predetermined stirring speed) to obtain a resultant slurry.
Step (vi): Predetermined amounts of at least one opacifier, a fourth portion of the defoamer and a surface modifier were mixed in the resultant slurry for a time period in the range of 5 minutes to 15 minutes (eighth predetermined time period) to obtain the coating composition.
Examples 1 to 3 were prepared by following the general procedure as provided above.
Comparative example 1: Preparation of coating composition without surface modifier
Comparative example 1 was carried out by following the similar procedure as provided in Experiment 1, except the surface modifier.
The ingredients and their predetermined amounts are enlisted in Table 1.
Table 1: Coating compositions prepared in accordance with the present disclosure (Examples 1 to 3) and the coating composition of the comparative example
Sr. No. Ingredients Function Example 1
(Amount in grams) Example 2
(Amount in grams) Example 3
(Amount in grams) Comparative Example 1
(Amount in grams)
1. Water Fluid medium 13.6 7.6 3.6 21.6
2. Benzisothiazolinone
(Biocide) Antibacterial performance 0.6 0.6 0.6 0.6
3. Kemox PHS
(pH stabilizer) Stabilization 0.3 0.3 0.3 0.3
4. Sodium hexametaphosphate
(Sequestering Agent) Softens water 0.3 0.3 0.3 0.3
5. Mineral oil defoamer (Defoamer) Reduces or eliminates foam in coatings 0.5 0.5 0.5 0.5
6. Glycol Ether
(Wetting agent) Promotes the spreading of a coating composition on a surface 0.7 0.7 0.7 0.7
7. Ammonium polyacrylate (Dispersing agent) Helps to separate particles in a coating composition and prevents them from clumping or settling 1.2 1.2 1.2 1.2
8. Rutile TiO2
(Pigment) Mineral that is made up of titanium dioxide that adds color or changes the appearance of a material by absorbing or scattering light 22 22 22 22
9. Talc
(Filler) Enhance certain properties and reduce costs 6 6 6 6
10. CaCO3
(Filler) Enhance certain properties and reduce costs 5 5 5 5
11. Texanol
(Coalescing agent) Facilitate the merging of dispersed particles, particularly during the drying or curing process 1.4 1.4 1.4 1.4
12. Benzimidazole carbamate (Preservative) Extending the shelf life 2 2 2 2
13.
Hydroxyethyl cellulose
(Thickener) Increases the viscosity of a coating composition without substantially changing its other properties 0.4 0.4 0.4 0.4
14.
Acrylic based emulsion
(Binder)
Forms a water-resistant film after drying 28 28 28 28
15. Ropaque™ Ultra-E opaque polymer (Opacifier) Added to make opaque or less transparent 10 10 10 10
16. KEMOSIL
(Alkaline dispersion of anionic amorphous silica)
(Surface modifier) To improve surface property or physical properties and functionality 8 14 18 0
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 coating composition of the present disclosure and the coating composition will give similar results.
Experiment 2: Characterization of the coating composition prepared in accordance with the present disclosure.
The coating composition of Example 1 prepared in accordance with the present disclosure was subjected for evaluating the QUV characteristics and Dirt Pick Up Resistance (DPUR) properties.
Test panels:
· The coating composition of Example 1 prepared in accordance with the present disclosure was applied on 6 x 3 inches panel by using a brush and a roller in a following sequence.
Primer (8 to 10 µm) + 2 coats putty (1 to 2 mm) + Primer (8 to 10 µm) + 2 coats (20 to 25 µm) of the coating composition of Example 1 of the present disclosure followed by drying at 32 ºC at 70 % R.H to obtain the test panels of the present disclosure.
· Same procedure was followed to obtain a comparative test panel coated with a coating composition without surface modifier (coating composition of comparative example 1 was used).
Figure 1 illustrates a schematic representation of (A) the coating composition without use of a surface modifier (comparative coating composition) and (B) the coating composition with use of a surface modifier prepared in accordance with the present disclosure, wherein “p” is 60 nm and “q” is 30 nm illustrating the particle sizes of the extender/pigment/other emulsion particles; and “z” is 10 nm illustrating the particle size of the colloidal nanosilica.
From Figure 1 (B) it is evident that the colloidal nanosilica particles (represented by tiny dots “z”) get arranged between the extender/pigment/other emulsion particles (represented by bigger dots “p” and “q”).
The surface modifier comprising colloidal nanosilica particles gets uniformly aligned throughout the film formed by the coating composition and provides surface enrichment with the inert particles after drying. The addition of colloidal nanosilica particles leads to achieve a smooth coated surface. This alignment of the surface modifier prevents the dirt/environmental dust from adhering and ingressing in the coated film obtained by applying the coating composition of the present disclosure. Hence, the dirt remains loosely adhered on the surface of the film and can be dislodged easily from the surface.
i) QUV Testing of the coating compositions (Examples 1 to 3) prepared in accordance with the present disclosure
The test panels were exposed to the QUV test conditions. The results are summarized in Table 2.
Table 2: QUV Test results of the test panels of the present disclosure.
Sr. No Time period CIELAB Color Space Observations
Dl Da Db DE
1. Test panels coated with the coating composition comprising 8% of surface modifier (Example 1) in accordance with the present disclosure
1(a) 250 hours -0.64 0.01 0.64 0.94 Darker and less yellow
1(b) 500 hours -0.81 -0.02 1.1 1.37 Darker, less green and less yellow
1(c) 750 hours -0.92 -0.05 1.3 1.59 Darker, less green and less yellow
1(d) 1000 hours -0.98 -0.04 1.53 1.82 Darker, less green and less yellow
2. Test panels coated with the coating composition comprising 14% of surface modifier (Example 2) in accordance with the present disclosure
2(a) 250 hours -0.63 0.07 0.54 0.83 Less dark, less green and less yellow
2(b) 500 hours -0.72 0.05 0.14 0.93 Less dark, less green and less yellow
2(c) 750 hours -0.87 0.05 0.54 1.03 Less dark, less green and less yellow
2(d) 1000 hours -0.98 0.02 0.94 1.36 Less dark, less green and less yellow
3. Test panels coated with the coating composition comprising 18% of surface modifier (Example 3) in accordance with the present disclosure
3(a) 250 hours -0.63 0.01 0.61 0.88 Less dark, less green and less yellow
3(b) 500 hours -0.75 0.03 0.69 0.93 Less dark, less green and less yellow
3(c) 750 hours -0.86 -.0.02 0.62 1.06 Less dark, less green and less yellow
3(d) 1000 hours -0.92 0.02 0.89 1.21 Less dark, less green and less yellow
4. Comparative test panels coated with a coating composition without surface modifier (Comparative Example 1)
4(a) 250 hours -0.62 -0.04 0.95 1.14 Darker, greener and yellower
4(b) 500 hours -0.82 -0.08 1.43 1.65 More dark, greener and yellower
4(c) 750 hours -0.97 -0.08 1.65 1.92 More dark, greener and yellower
4(d) 1000 hours -1.08 -0.11 1.92 2.21 More dark, greener and yellower
The CIELAB color space expresses the color as three values: dL* for perceptual lightness and da* and db* for the four unique colors of human vision: red, green, blue and yellow.
From Table 2, it is observed that the DE values (delta value) for the test panels coated with the coating composition of the present disclosure (1.82, 1.36 and 1.21), after 1000 hours is less than DE value of the comparative test panels (2.21), which indicates that the test panels coated by applying the coating composition of the present disclosure are more durable when compared with the comparative test panel. Further, the lower DE value of the coating compositions prepared in accordance with the present disclosure confirms the improved durability and improved QUV resistance as compared to the comparative coating composition (without surface modifier).
Thus, from Table 2 it is confirmed that the durability of the coating composition prepared in accordance with the present disclosure is increased due to the incorporation of the surface modifier.
ii) Dirt Pick Up Resistance (DPUR) properties of the coating composition (Examples 1 to 3) prepared in accordance with the present disclosure.
To study the dirt pick up resistance (DPUR) of the coating composition prepared in accordance with the present disclosure (Examples 1 to 3), the dirt simulant iron oxide was used as coloured, cationic, hydrophilic dirt simulant. Other dirt simulant such as, carbon black pigment can also be used. Apart from this, the dust composition (garden soil in slurry form) can also be used to simulate the deposition occurring from dew, rain droplets and other liquid transfer even.
The test panels were coated by using the coating composition prepared in accordance with the present disclosure (Examples 1 to 3) and the coating composition without surface modifier (comparative example 1). These panels were then uniformly coated with the 50% garden soil slurry (a 1:1 mixture of soil and water) and allowed to dry, simulating natural dirt settling. After drying, the panels were cleaned using running water to assess the ease with which the dirt could be removed. This method provides a visual and practical measure of DPUR, reflecting the coating's ability to resist and release particulate matter after exposure.
The evaluation was mainly focused on two key aspects: dirt adhesion after drying and cleanability after rinsing. A good DPUR performance was indicated by lower visible staining post-drying and a cleaner surface after rinsing under water.
In this study, the coating compositions of Examples 1 to 3, which include the surface modifier, demonstrated a superior DPUR performance as compared to the comparative Example 1, which is devoid of the surface modifier. Specifically, the coating compositions of the present disclosure (Examples 1 to 3) exhibited minimal dirt adhesion and high cleanability, with most of the soil slurry being easily removed under running water. In contrast, the coating of the comparative Example 1 retained noticeably more dirt, both after drying and rinsing, indicating inferior resistance to dirt pick-up, as shown in Figure 2.
Figure 2 illustrate images of demonstration of Dirt Pick Up Resistance (DPUR) properties of the coating composition of the present disclosure (Examples 1 to 3) as compared to the coating composition prepared in comparative example 1 coated on the test panels.
It is evident from Figure 2 that the test panel coated with the composition of Comparative Example 1 shows significant dirt accumulation at the bottom, whereas the panels coated with the coating compositions of Examples 1 to 3 exhibit no dirt at the bottom. This clearly indicates that the coating compositions of the present disclosure has improved DPUR properties.
These results clearly confirm that the inclusion of the surface modifier in the coating composition provides a significant improvement in resistance to dirt accumulation and enhances the self-cleaning or easy-to-clean behaviour of the coating composition. Thus, the coating compositions of the present disclosure (Examples 1 to 3) are more effective and durable than the coating composition without surface modifier (Comparative Example 1).

TECHNICAL ADVANCES AND ECONOMIC SIGNIFICANCE
The present disclosure described hereinabove has several technical advantages including, but not limited to, the realization of:
? a coating composition, that has
· improved durability;
· improved dirt pick up resistance;
· improved QUV resistance; and
· improved pH stability;
and
? a process for the preparation of coating composition that
· is simple; and
· environment friendly.
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.
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.
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.
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.
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:WE CLAIM:
1. A coating composition comprising
· a homogenous blend of an emulsion in an amount in the range of 80 mass% to 99 mass%; and
· a surface modifier in an amount in the range of 1 mass% to 20 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said coating composition.
2. The coating composition as claimed in claim 1, wherein said surface modifier is in the form of a colloidal dispersion of silica particles in water and wherein an amount of said silica particles is in the range of 10 mass% to 30 mass% with respect to the total amount of said colloidal dispersion.
3. The coating composition as claimed in claim 2, wherein said silica particles have a particle size in the range of 7 nm to 20 nm.
4. The coating composition as claimed in claim 1, wherein said homogenous blend of said emulsion comprises
· at least one binder in an amount in the range of 25 mass% to 35 mass%;
· at least one filler in an amount in the range of 5 mass% to 18 mass%;
· at least one biocide in an amount in the range of 0.5 mass% to 2 mass%;
· at least one pigment in an amount in the range of 15 mass% to 25 mass%;
· at least one preservative in an amount in the range of 1 mass% to 3 mass%;
· at least one opacifier in an amount in the range of 5 mass% to 15 mass%;
· at least one additive in an amount in the range of 1 mass% to 15 mass%; and
· water in an amount in the range of 3 mass% to 20 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said coating composition.
5. The coating composition as claimed in claim 4, wherein
· said binder is acrylic based emulsion;
· said filler is selected from the group consisting of calcium carbonate, talc and dolomite;
· said biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, benzisothiazolinone, octylisothiazolinone, dichlorooctyl isothiazolinone and butylisothiazolinone;
· said pigment is rutile titanium dioxide;
· said preservative is selected from the group consisting of benzimidazole carbamate, urea derivatives and zinc pyrithione based preservatives;
· said opacifier is polymeric opacifier; and
· said additive is at least one selected from the group consisting of a pH stabilizer, a sequestering agent, a defoamer, a wetting agent, a dispersing agent, a coalescing agent, and a thickener.
6. The coating composition as claimed in claim 5, wherein
· said pH stabilizer is a synergistic mixture of alkaline compounds with special organics;
· said sequestering agent is selected from sodium hexametaphosphate and potassium pyrophosphate;
· said defoamer is mineral oil defoamer;
· said wetting agent is selected from an ethoxylate and a polyether; wherein said polyether is glycol ether;
· said dispersing agent is selected from ammonium polyacrylate and sodium polyacrylate;
· said coalescing agent is (3-hydroxy-2,2,4-trimethylpentyl)2-methylpropanoate; and
· said thickener is hydroxyethyl cellulose.
7. The coating composition as claimed in claim 5, wherein
· said pH stabilizer is present in an amount in the range of 0.1 mass% to 0.5 mass%;
· said sequestering agent is present in an amount in the range of 0.2 mass% to 0.6 mass%;
· said defoamer is present in an amount in the range of 0.3 mass% to 3 mass%;
· said wetting agent is present in an amount in the range of 0.2 mass% to 1 mass%;
· said dispersing agent is present in an amount in the range of 0.4 mass% to 3 mass%;
· said coalescing agent is present in an amount in the range of 0.5 mass% to 2.5 mass%; and
· said thickener is present in an amount in the range of 0.2 mass% to 1 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said coating composition.
8. A process for the preparation of a coating composition, said process comprising the following steps:
i. mixing predetermined amounts of a first portion of water and a first portion of a biocide under stirring at a first predetermined speed at a first predetermined temperature for a first predetermined time period to obtain a first slurry;
ii. adding predetermined amounts of at least one pH stabilizer, at least one sequestering agent and a first portion of a defoamer in said first slurry under stirring at said first predetermined speed for a second predetermined time period followed by adding predetermined amounts of at least one wetting agent, a first portion of at least one dispersing agent, and a second portion of said defoamer under stirring at said first predetermined speed for a third predetermined time period to obtain a second slurry;
iii. increasing the stirring speed from said first predetermined speed to a second predetermined speed followed by adding a second portion of said biocide, predetermined amounts of at least one pigment, at least one filler and a second portion of water in said second slurry for a fourth predetermined time period to obtain a third slurry;
iv. adding a second portion of at least one dispersing agent, predetermined amounts of at least one coalescing agent, and at least one preservative in said third slurry under stirring by maintaining said second predetermined stirring speed for a fifth predetermined time period followed by adding a predetermined amount of a thickener and a third portion of water for a sixth predetermined time period to obtain an intermediate slurry;
v. adding a predetermined amount of at least one binder and a third portion of said defoamer in said intermediate slurry at a second predetermined temperature for a seventh predetermined time period under stirring at a third predetermined stirring speed to obtain a resultant slurry; and
vi. mixing predetermined amounts of at least one opacifier, a fourth portion of said defoamer and a surface modifier in said resultant slurry for an eighth predetermined time period to obtain said coating composition.
9. The process as claimed in claim 8, wherein
· said binder is acrylic based emulsion;
· said filler is selected from the group consisting of calcium carbonate, talc and dolomite;
· said biocide is selected from the group consisting of methylisothiazolinone, chloromethylisothiazolinone, benzisothi-azolinone, octylisothiazolinone, dichlorooctylisothiazolinone and butylisothiazolinone;
· said pigment is rutile titanium dioxide;
· said preservative is selected from the group consisting of benzimidazole carbamate, urea derivatives and zinc pyrithione based preservatives;
· said opacifier is polymeric opacifier;
· said pH stabilizer is a synergistic mixture of alkaline compounds with special organics;
· said sequestering agent is selected from sodium hexametaphosphate and potassium pyrophosphate;
· said defoamer is mineral oil defoamer;
· said wetting agent is selected from an ethoxylate and a polyether; wherein said polyether is glycol ether;
· said dispersing agent is selected from ammonium polyacrylate and sodium polyacrylate;
· said coalescing agent is (3-hydroxy-2,2,4-trimethylpentyl)2-methylpropanoate; and
· said thickener is hydroxyethyl cellulose.
10. The process as claimed in claim 8, wherein
· said binder is present in an amount in the range of 25 mass% to 35 mass%;
· said filler is present in an amount in the range of 5 mass% to 18 mass%;
· said biocide is present in an amount in the range of 0.5 mass% to 2 mass%;
· said pigment is present in an amount in the range of 15 mass% to 25 mass%;
· said preservative is present in an amount in the range of 1 mass% to 3 mass%;
· said opacifier is present in an amount in the range of 5 mass% to 15 mass%;
· said pH stabilizer is present in an amount in the range of 0.1 mass% to 0.5 mass%;
· said sequestering agent is present in an amount in the range of 0.2 mass% to 0.6 mass%;
· said defoamer is present in an amount in the range of 0.3 mass% to 3 mass%;
· said wetting agent is present in an amount in the range of 0.2 mass% to 1 mass%;
· said dispersing agent is present in an amount in the range of 0.4 mass% to 3 mass%;
· said coalescing agent is present in an amount in the range of 0.5 mass% to 2.5 mass%;
· said thickener is present in an amount in the range of 0.2 mass% to 1 mass%;
· said surface modifier is present in an amount in the range of 1 mass% to 20 mass%; and
· water is present in an amount in the range of 3 mass% to 20 mass%,
wherein said mass% of each ingredient is with respect to the total mass of said coating composition.
11. The process as claimed in claim 8, wherein said surface modifier is in the form of a colloidal dispersion of silica particles in water and wherein an amount of said silica particles is in the range of 10 mass% to 30 mass% with respect to the total amount of said colloidal dispersion.
12. The process as claimed in claim 11, wherein said silica particles have a particle size in the range of 7 nm to 20 nm.
13. The process as claimed in claim 8, wherein
· said first portion of said biocide is in the range of 25 mass% to 30 mass%; and
· said second portion of said biocide is in the range of 70 mass% to 75 mass%,
wherein said mass% of each portion of said biocide is with respect to the total mass of said biocide.
14. The process as claimed in claim 8, wherein
· said first portion of said defoamer is in the range of 45 mass% to 55 mass%;
· said second portion of said defoamer is in the range of 15 mass% to 20 mass%;
· said third portion of said defoamer is in the range of 15 mass% to 20 mass%; and
· said fourth portion of said defoamer is in the range of 15 mass% to 20 mass%,
wherein said mass% of each portion of said defoamer is with respect to the total mass of said defoamer.
15. The process as claimed in claim 8, wherein
· said first portion of said dispersing agent is in the range of 45 mass% to 55 mass%; and
· said second portion of said dispersing agent is in the range of 45 mass% to 55 mass%,
wherein said mass% of each portion of said dispersing agent is with respect to the total mass of said dispersing agent.
16. The process as claimed in claim 8, wherein
· said first portion of water is in the range of 80 mass% to 85 mass%;
· said second portion of water is in the range of 5 mass% to 15 mass%; and
· said third portion of water is in the range of 5 mass% to 15 mass%,
wherein said mass% of each portion of water is with respect to the total mass of water.
17. The process as claimed in claim 8, wherein
· said first predetermined stirring speed is in the range of 10 m/sec to 12 m/sec;
· said second predetermined stirring speed is in the range of 20 m/sec to 22 m/sec; and
· said third predetermined stirring speed is in the range of 10 m/sec to 12 m/sec.
18. The process as claimed in claim 8, wherein
· said first predetermined temperature is in the range of 35 oC to 45 oC; and
· said second predetermined temperature is in the range of 35 oC to 45 oC.
19. The process as claimed in claim 8, wherein
· said first predetermined time period is in the range of 5 minutes to 10 minutes;
· said second predetermined time period is in the range of 5 minutes to 10 minutes;
· said third predetermined time period is in the range of 5 minutes to 10 minutes;
· said fourth predetermined time period is in the range of 5 minutes to 10 minutes;
· said fifth predetermined time period is in the range of 10 minutes to 15 minutes;
· said sixth predetermined time period is in the range of 15 minutes to 45 minutes;
· said seventh predetermined time period is in the range of 15 minutes to 25 minutes; and
· said eighth predetermined time period is in the range of 5 minutes to 15 minutes.
Dated this 23rd day of July, 2025

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
OF R. K. DEWAN & CO.
AUTHORIZED AGENT OF APPLICANT

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT MUMBAI