Claims:WE CLAIM:
1. An anti-algal paint composition comprising:
a) at least one pigment in an amount in the range of 15 to 25 wt% of the total weight of the composition;
b) at least one emulsion in an amount in the range of 25 to 35 wt% of the total weight of the composition;
c) at least one biocide selected from the group consisting of copper melamine complex and copper carbonate, in an amount in the range of 0.1 to1.0 wt% of the total weight of the composition;
d) water in an amount in the range of 12 to 18 wt% of the total weight of the composition; and
e) excipients selected from the group consisting of fillers, opacifiers, dispersing agents, wetting agents, coalescing agents, thickening agents, alkalizing agents, defoaming agents and softening agents; wherein the total amount of said excipients is in the range of 30 to 36 wt% of the total weight of the composition.
2. The composition as claimed in claim 1, wherein the composition has pigment volume concentration in the range of 45 to 55%.
3. The composition as claimed in claim 1, wherein said emulsion is a styrene acrylic emulsion comprising styrene acrylic polymer in an amount in the range of 40 to 60 wt% of the total weight of the said emulsion.
4. The composition as claimed in claim 1, wherein said emulsion contains 50% styrene-acrylic polymer.
5. The composition as claimed in claim 1, wherein said pigment is titanium dioxide.
6. The composition as claimed in claim 1, wherein said composition comprises:
i) titanium dioxide in an amount of 21 wt% of the total weight of the composition;
ii) styrene-acrylic emulsion in an amount of 30.6 wt% of the total weight of the composition;
iii) copper melamine complex or copper carbonate, in an amount in the range of 0.2 to 0.7 wt% of the total weight of the composition;
iv) water in an amount of 14 to 15 wt% of the total weight of the composition; and
v) excipients comprising calcium carbonate in an amount of 13 wt% of the total weight of the composition, styrene acrylic hollow latex emulsion in an amount of 12 wt% of the total weight of the composition, aluminium silicate in an amount of 6 wt% of the total weight of the composition, 2,2,4-trimethylpentane-1,3-diol mono isobutyrate in an amount of 1 wt% of the total weight of the composition, ammonium salt of polyacrylic acid in an amount of 0.5 wt% of the total weight of the composition, nonyl phenol ethoxylate in an amount of 0.4 wt% of the total weight of the composition, 2-hydroxyethyl cellulose in an amount of 0.4 wt% of the total weight of the composition, liquor ammonia in an amount of 0.1 wt% of the total weight of the composition, metallic salt of fatty acid in mineral oil, in an amount of 0.1 wt% of the total weight of the composition, and tetra potassium pyrophosphate in an amount of 0.2 wt% of the total weight of the composition.
7. The composition as claimed in claim 1, wherein the composition has pigment volume concentration of 50.6%.
8. The composition as claimed in claim 1, wherein said filler is at least one selected from calcium carbonate and aluminium silicate, in an amount in the range of 15 to 25 wt% of the total weight of the composition.
9. The composition as claimed in claim 1, wherein said opacifier is an styrene Acrylic hollow latex emulsion, in an amount in the range of 10 to 15 wt% of the total weight of the composition.
10. The composition as claimed in claim 1, wherein said coalescing agent is 2,2,4-trimethylpentane-1,3-diol mono isobutyrate, in an amount in the range of 0.5 to 1.5 wt% of the total weight of the composition.
11. The composition as claimed in claim 1, wherein said dispersing agent is 2-propenoic acid ammonium salt, in an amount in the range of 0.2 to 1.0 wt% of the total weight of the composition.
12. The composition as claimed in claim 1, wherein said wetting agent is nonyl phenol ethoxylate, in an amount in the range of 0.2 to 0.6 wt% of the total weight of the composition.
13. The composition as claimed in claim 1, wherein said thickening agent is 2-hydroxyethyl cellulose, in an amount in the range of 0.2 to 0.6 wt% of the total weight of the composition.
14. The composition as claimed in claim 1, wherein said alkalizing agent is liquor ammonia, in an amount in the range of 0.05 to 0.2 wt% of the total weight of the composition.
15. The composition as claimed in claim 1, wherein said defoaming agent is a metallic salt of fatty acid in mineral oil, in an amount in the range of 0.05 to 0.2 wt% of the total weight of the composition.
16. The composition as claimed in claim 1, wherein said softening agent is tetra potassium pyrophosphate, in an amount in the range of 0.05 to 0.4 wt% of the total weight of the composition.
17. A process for preparing an anti-algal paint composition, said process comprising the following steps:
I. adding a predetermined amount of at least one softening agent to a predetermined amount of water and stirring at a speed in the range of 200 to 1000 rpm to obtain soft water;
II. mixing predetermined amounts of at least one dispersing agent and at least one wetting agent with said soft water under stirring to obtain a first mixture;
III. adding at least one thickening agent to the first mixture at a stirring speed in the range of 1800 to 2200 rpm, followed by mixing at least one alkalizing agent to obtain a second mixture;
IV. admixing at least one pigment, at least one filler and at least one biocide with the second mixture, to obtain a viscous mixture; and
V. blending at least one defoaming agent, at least one coalescing agent, at least one emulsion and at least one opacifier with the viscous mixture at a stirring speed in the range of 200 to 1000 rpm to obtain the anti-algal paint composition.
, Description:FIELD
The present disclosure relates to the field of paints and a process for manufacturing paints.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The demand for exterior paints is rising due to urbanization and modernization. The growth of microbial films on a coated surface not only spoils the aesthetics of the coated surface, but also degrades the performance of the coating and can cause health hazard. Often, biocides are commonly added to paint formulations to provide protection during storage and post application on dried thin paint films against algal and fungal growth. Conventionally, urea based compounds (e.g. Diuron) are used as algaecide in water based paint formulation. Hence, a large quantity of diuron is used in premium exterior paints to boost the long term durability. During rainfall the urea based algaecide leaches out of the water paint film and eventually reaches a water source like river, sea, lake etc. The green algae found beneath these water bodies are rich in fats, amino-acids and proteins and hence, play an important role in aquatic food chain. The leached diuron kills these green algae owing to its herbicidal effect by inhibiting the photosynthesis process and subsequently disturbs the food chain. Hence, diuron is toxic to terrestrial and aquatic organisms.
Therefore, there is felt a need to develop a water based paint composition for controlling algae, based on biocides that are non-toxic to terrestrial and aquatic life.
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 to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
It is an object of the present disclosure to provide a paint composition.
It is another object of the present disclosure to provide an anti-algal paint composition that controls the breeding and growth of algae.
It is yet another object of the present disclosure to provide a process for preparing an anti-algal paint 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 an anti-algal paint composition and a process for preparation thereof.
In one aspect, the present disclosure provides an anti-algal paint composition comprising 15 to 25 wt% of at least one pigment, 25 to 35 wt% of at least one emulsion, 0.1 to 1.0 wt% biocide selected from copper melamine complex and copper carbonate, 12 to 18 wt% water based on the total weight of the composition, and excipients selected from the group consisting of fillers, opacifiers, dispersing agents, wetting agents, coalescing agents, thickening agents, alkalizing agents, defoaming agent and softening agent. The total amount of the excipients is in the range of 30 to 36 wt% of the total weight of the composition.
In another aspect, the present disclosure provides a process for preparing an anti-algal paint composition. The process comprises softening predetermined amount of water by adding a predetermined amount of at least one softening agent in a reactor vessel, at a stirring speed in the range of 200 to 400 rpm to obtain soft water. Predetermined amounts of at least one dispersing agent and at least one wetting agent are mixed with the soft water under stirring to obtain a first mixture. At least one thickening agent is added to the first mixture at a stirring speed in the range of 1800 to 2200 rpm, followed by mixing at least one alkalizing agent to obtain a second mixture. At least one pigment, at least one filler and at least one biocide are admixed with the second mixture, to obtain a viscous mixture. At least one defoaming agent, at least one coalescing agent, at least one emulsion and at least one opacifier are blended with the viscous mixture at a stirring speed in the range of 600 to 800 rpm to obtain the anti-algal paint composition.
DETAILED DESCRIPTION
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.
Exterior emulsion paint formulations comprise conventional / standard algaecide based on urea derived algaecide (e.g. Diuron). However, diuron is toxic or slightly toxic to birds, moderately toxic to most aquatic animals (fish and aquatic invertebrates). Further, Diuron is a very specific and sensitive inhibitor of photosynthesis and is banned in many developed countries due to environmental and human health concerns.
The present disclosure relates to an anti-algal paint composition and a process for preparation thereof.
In a first aspect, the present disclosure provides an anti-algal paint composition comprising 15 to 25 wt% of at least one pigment, 25 to 35 wt% of at least one emulsion, 0.1 to 1.0 wt% biocide selected from copper melamine complex and copper carbonate, 12 to 18 wt% water based on the total weight of the composition, and predetermined amounts of excipients selected from the group consisting of fillers, opacifiers, coalescing agents, dispersing agents, wetting agents, thickening agents, alkalizing agents, defoaming agents and softening agents. The total amount of the excipients is in the range of 30 to 36 wt% of the total weight of the composition.
In accordance with the embodiments of the present disclosure, the composition has pigment volume concentration in the range of 45 to 55%.
Paint is a pigmented liquid composition, which is applied to the surface of substrate as a thin layer, and which on drying converts to a solid film.
A paint includes pigments, which are fine powdered solids, which provide the color and opacity (hiding power) to the paint.
In accordance with the embodiments of the present disclosure, the pigment is an inorganic pigment titanium dioxide (TiO2).
The film-forming component of paint is known as emulsion. The emulsion imparts gloss, durability, flexibility and toughness to dried paint film. Emulsions include synthetic or natural macropolymers.
In accordance with the embodiments of the present disclosure, the emulsion (film forming agent) is styrene acrylic emulsion comprising styrene acrylic polymer in an amount in the range of 40 to 60 wt% of the total weight of the emulsion, and water in an amount in the range of 60 to 40 wt% of the emulsion.
In accordance with one embodiment of the present disclosure, the emulsion (film forming agent) is styrene acrylic emulsion comprising 50 wt% styrene acrylic polymer of the total weight of the emulsion, and 50 wt% water of the total weight the polymeric emulsion.
A biocide is a chemical substance used to control the growth of organisms that cause damage to natural or manufactured products and are harmful to human or animal health.
In accordance with the embodiments of the present disclosure, the biocide is at least one anti-algal compound selected from the group consisting of copper melamine complex and Copper carbonate.
In accordance with one embodiment of the present disclosure, the biocide is copper melamine complex.
The anti-algal paint composition of the present disclosure comprising 0.3 or 0.6 wt% of copper melamine complex has anti-algal activity that is comparable to conventional anti-algal paint composition containing 1% urea based algaecide.
In accordance with another embodiment of the present disclosure, the biocide is copper carbonate.
The anti-algal paint composition of the present disclosure comprising 0.3 wt% of copper carbonate has anti-algal activity that is comparable to conventional anti-algal paint composition containing 1% urea based algaecide.
The anti-algal paint composition of the present disclosure comprising 0.6 wt% of copper carbonate has 60% higher anti-algal activity as compared to the conventional anti-algal paint composition containing 1% urea based algaecide.
In accordance with the preferred embodiments of the present disclosure, the amount of the biocide is in the range of 0.3 to 1 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the biocide is 0.3 wt% of the total weight the composition.
In accordance with another embodiment of the present disclosure, the amount of the biocide is 0.6 wt% of the total weight the composition.
Granular solids incorporated in paint to impart toughness, texture and to reduce the cost of the paint are known as Fillers. Fillers serve to thicken the film, support the paint structure and make up the volume of the paint. Fillers are usually cheap and inert materials.
In accordance with the embodiments of the present disclosure, the filler is at least one selected from the group consisting of calcium carbonate (marble powder) and aluminium silicate (anhydrous) (sold by English Indian clays limited under the trade name Himatex), in an amount in the range of 15 to 25 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the filler is calcium carbonate (marble powder), in an amount of 13 wt% of the total weight of the composition and aluminium silicate (anhydrous), in an amount of 6 wt% of the total weight of the composition.
Marble powder is a substance made from calcium carbonate. Introducing calcium carbonate (marble powder) into water based paint thickens the film, support the paint structure and make up the volume of the paint without affecting the color.
An opacifier is a substance added to a paint formulation to render the paint impervious to visible light.
In accordance with the embodiments of the present disclosure, the opacifier is styrene acrylic hollow latex emulsion (sold by Rohm and Haas India Pvt. Ltd. under the trade name Ultra E opaque polymer), in an amount in the range of 10 to 15 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the opacifier is 12 wt% of the total weight of the composition.
The opacifier styrene acrylic hollow latex emulsion is an opaque polymer and its function is to give dry hiding.
Coalescence refers to a mechanism that involves drying followed by interpenetration and fusion of formerly discrete granular particles. Paints that are aqueous dispersions are prepared by emulsion polymerization, which cure by a process called coalescence where first the water (solvent) evaporates and then the granular particles draw together, soften and fuse together. Such paints cannot redissolve in the solvent/water. Thus, coalescing agent help the paint in the process of coalescence.
In accordance with the embodiments of the present disclosure, the coalescing agent is 2,2,4-trimethylpentane-1,3-diol mono isobutyrate (sold by Eastman Chemical Company under the trade name Texanol) in an amount in the range of 0.5 to 1.5 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the coalescing agent is 1.0 wt% of the total weight of the composition.
Surfactant is a chemical compound that lowers the interfacial tension or surface tension between two fluids. The surfactants are classified according to polar head group. A non-ionic surfactant has no charged groups in its head. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.
In accordance with the embodiments of the present disclosure, the dispersing agent is an anionic surfactant, 2-Propenoic Acid Ammonium Salt (ammonium salt of polyacrylic acid sold by Colourchem limited under the trade name Mowiplus XW330), in an amount in the range of 0.2 to 1.0 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the dispersing agent is 0.5 wt% of the total weight of the composition.
When the head of an ionic surfactant carries a net positive or negative charge the surfactant is known as an ionic surfactant.
In accordance with the embodiments of the present disclosure, the wetting agent (non-ionic surfactant) is nonyl phenol ethoxylate, in an amount in the range of 0.2 to 0.6 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the wetting agent (non-ionic surfactant) is 0.4 wt% of the total weight of the composition.
A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Thickeners also improve the suspension of other ingredients or emulsions which increases the stability of the product. Cellulosic thickener is a hydrophilic white powder in pure form, which dissolves in cold water, forming a clear viscous solution or gel. Cellulose thickeners are used as emulsifiers, suspending agents and thickeners in many applications.
In accordance with the embodiments of the present disclosure, the thickening agent is cellulosic thickener 2-hydroxyethyl cellulose (HECHV), in an amount in the range of 0.2 to 0.6 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the thickening agent is 0.4 wt% of the total weight of the composition.
In accordance with the embodiments of the present disclosure, the alkalizing agent is liquor ammonia, in an amount in the range of 0.05 to 0.2 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the alkalizing agent is 0.2 wt% of the total weight of the composition.
In accordance with the embodiments of the present disclosure, the amount of ammonia in liquor ammonia (aqueous ammonia) is in the range of 10 to 50 wt%.
In accordance with one embodiment of the present disclosure, the amount of ammonia in liquor ammonia (aqueous ammonia) is 33 wt%.
An anti-foaming or defoaming agent is a chemical additive that reduces and hinders the formation of foam in liquids during an industrial process. A defoaming agent has a low viscosity and spreads rapidly on foamy surfaces.
In accordance with the embodiments of the present disclosure, the defoaming agent is metallic salt of fatty acid in mineral oil (sold by elementis specialties under the trade name Dapro DF4164), in an amount in the range of 0.05 to 0.2 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the defoaming agent is 0.2 wt% of the total weight of the composition.
A softening agent is a water softener or emulsifier that combines with salts of magnesium and calcium to remove the calcium, magnesium, and certain other metal cations in hard water.
In accordance with the embodiments of the present disclosure, the softening agent is tetra potassium pyrophosphate (TKPP) in an amount in the range of 0.05 to 0.4 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of the softening agent is 0.4 wt% of the total weight of the composition.
In accordance with the preferred embodiments of the present disclosure, the amount of water is in the range of 13 to 15 wt% of the total weight of the composition.
In accordance with one embodiment of the present disclosure, the amount of water is 14.40 wt% of the total weight of the composition.
In accordance with another embodiment of the present disclosure, the amount of water is 14.10 wt% of the total weight of the composition.
In an exemplary embodiment of the present disclosure, the anti-algal paint composition comprises 21 wt% of titanium dioxide as pigment, 30.6 wt% of styrene-acrylic emulsion as film forming agent, 0.3 to 1 wt% of biocide is at least one of copper melamine complex and copper carbonate, 14 to 15 wt% of water, and the excipients are 13 wt% of calcium carbonate (marble powder) as filler, 12 wt% of styrene acrylic hollow latex emulsion as opacifier, 6 wt% of aluminium silicate (anhydrous) (kaolin) as filler, 1 wt% of 2,2,4-trimethylpentane-1,3-diol mono isobutyrate as coalescing agent, ammonium salt of polyacrylic acid (0.5 wt%) as dispersing agent (anionic surfactant), nonyl phenol ethoxylate (sold by Sunshield under the trade name Atsolyn A1000) (0.4 wt%) as wetting agent (non-ionic surfactant), 2-hydroxyethyl cellulose (0.4 wt%) as thickening agent, 0.1 wt% of aqueous ammonia as base, 0.1 wt% of metallic salt of fatty acid in mineral oil (sold by elementis specialities under the trade name Dapro DF 4165) as defoaming agent, and 0.2 wt% of Tetra potassium pyrophosphate (TKPP) as softening agent. The composition has pigment volume concentration of 50.6 %. The volume solids of the composition is 40.4%.
In another aspect, the present disclosure provides a process for preparing an anti-algal paint composition. The process comprises softening predetermined amount of water by adding a predetermined amount of at least one softening agent in a reactor vessel, at a stirring speed in the range of 200 to 400 rpm to obtain soft water. Predetermined amounts of at least one dispersing agent and at least one wetting agent are mixed with the soft water under stirring to obtain a first mixture. At least one thickening agent is added to the first mixture at a stirring speed in the range of 1800 to 2200 rpm, followed by mixing at least one alkalizing agent to obtain a second mixture. At least one pigment, at least one filler and at least one biocide are admixed with the second mixture, to obtain a viscous mixture. At least one defoaming agent, at least one coalescing agent, at least one emulsion and at least one opacifier are blended with the viscous mixture at a stirring speed in the range of 600 to 800 rpm to obtain the anti-algal paint composition.
In the present disclosure, the copper melamine complex does not disperse homogeneously throughout the continuous phase on direct addition. Therefore, it is discharged along with the other powders namely; pigment (titanium dioxide), fillers (anhydrous aluminium silicate) and calcium carbonate (marble powder) at an increased rpm of 2200.
The dried paint film is porous in nature, and when the dried paint comes in direct contact with water, the water loving ingredients migrate to the surface and leach out. Therefore, the conventional urea based algaecides, whose solubility in water increases in the presence of surfactants, leach out along with other water soluble ingredients leading to decrease in the effective amount of these algaecide in the paint thereby resulting in higher algal growth.
On the contrary, the copper carbonate and copper melamine complex are insoluble in continuous media i.e. water. Therefore, both copper carbonate and copper melamine complex are retained in the paint film for longer period of time. Thus, both these copper compounds, even though present in lower amounts in the experimental paint compositions as compared to the conventional urea based algaecides, show better anti-algal performance over longer duration of time than the conventional urea based algaecide.
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:
Example 1: Preparation of an anti-algal paint composition
1 (a): Synthesis of copper melamine complex
Copper (I) chloride (217 g) was mixed in acetonitrile (30 L). This solution was filtered through 0.45 um nylon membrane filter using vacuum filtration technique. Subsequently, Melamine (126 g) was added to the above solution under vigorous stirring and the suspension was sealed in a round bottom flask and heated to 100 oC with continuous stirring in an oil bath. After 22 h, the acetonitrile had lost the color associated with the solution of CuCl. The suspended solid was collected by means of vacuum filtration technique, subsequently rinsed with fresh acetonitrile and diethyl ether, and then dried under vacuum for overnight to obtain Copper melamine complex (230 g).
Example 1 (b): Preparation of 1 kg of an aqueous exterior paint using 0.3 wt% copper melamine complex as anti-algal additive.
Tetra potassium pyrophosphate (2 g, 0.2 wt%) was added to water (144.0 g, 14.40 wt%), to soften the water. Ammonium salt of polyacrylic acid (5 g, 0.5 wt%) (Mowiplus XW 330) and nonyl phenol ethoxylate (Atsolyn A1000)(4 g, 0.4 wt%) were discharged into the vessel at a stirring speed of 200-400 rpm for 10 minutes to obtain a first mixture. Then, 2-hydroxyethyl cellulose (4 g, 0.4 wt%) was added to the vessel and the stirring speed was increased to 2000 rpm. After 5 minutes, aqueous ammonia (1 g, 0.1 wt%) was slowly added and the contents in vessel were stirred for 25 minutes to obtain a second mixture. Then, titanium dioxide (210 g, 21 wt%), aluminium silicate (anhydrous) (60 g, 6 wt%), calcium carbonate (marble powder) (130 g, 13 wt%) and copper melamine complex (3 g, 0.3 wt%) were discharged into the vessel at an increased stirring speed of 2200 rpm to obtain a viscous mixture. Followed by addition of metallic salt of fatty acid in mineral oil (Dapro DF4164) (1 g, 0.1 wt%) as defoaming agent, 2,2,4-trimethylpentane-1,3-diol mono isobutyrate (10 g, 1 wt%), styrene-acrylic emulsion (306 g, 30.6 wt%), and styrene acrylic hollow latex emulsion (120 g, 12 wt%) were discharged into the vessel at 800 rpm for 15 minutes to obtain an anti-algal paint composition as represented in Table 1.
Example 2: Preparation of 1 kg of an aqueous exterior paint using 0.6 wt% copper melamine complex as anti-algal additive.
Example 1(b), was repeated using 0.6 wt% of copper melamine complex as an anti-algal additive in place of 0.3 wt%, and 14.10 wt% water in place of 14.40 wt% to obtain an anti-algal paint composition as represented in Table 1.
Table 1: Paint composition (1 kg) prepared using 0.3 and 0.6 wt% copper melamine complex as an anti-algal additive
Example 1 (b) Example 2
Ingredient Dosage (wt%) Dosage (wt%)
Water 14.40 14.10
TKPP 0.2 0.2
Ammonium salt of polyacrylic acid (Mowiplus XW330) 0.5 0.5
Nonyl phenol ethoxylate (Atsolyn A1000) 0.4 0.4
2-hydroxyethyl cellulose (HECHV) 0.4 0.4
Aqueous Ammonia 0.1 0.1
TiO2 (Rutile 902+) 21 21
aluminium silicate anhydrous (Himatex) 6 6
calcium carbonate (marble powder) 13 13
Copper melamine complex 0.3 0.6
metallic salt of fatty acid in mineral oil (Dapro DF4164) 0.1 0.1
2,2,4-trimethylpentane-1,3-diol mono isobutyrate (Texanol) 1 1
styrene acrylic hollow latex emulsion (Opacifier) 12 12
Emulsion (film forming agent) 30.6 30.6
Total 100 100

Example 3: Preparation of 1 kg of an aqueous exterior paint using 0.3 wt% copper carbonate as anti-algal additive.
Tetra potassium pyrophosphate (2 g, 0.2 wt%) was added to water (144 g, 14.40 wt%), to soften the water. Ammonium salt of polyacrylic acid (5 g, 0.5wt%) (Mowiplus XW 330) and nonyl phenol ethoxylate (Atsolyn A1000) (4 g, 0.4 wt%) were discharged into the vessel at a stirring speed of 200-400 rpm for 10 minutes to obtain a first mixture. Then, 2-hydroxyethyl cellulose (4 g, 0.4 wt%) was added to the vessel and the stirring speed was increased to 2000 rpm. After 5 minutes, aqueous ammonia (1 g, 0.1 wt%) was slowly added and the contents in vessel were stirred for 25 minutes to obtain a second mixture. Then, titanium dioxide (210 g, 21 wt%), aluminium silicate (anhydrous) (60 g, 6 wt%), calcium carbonate (marble powder) (130 g, 13 wt%) and copper carbonate powder (3 g, 0.3 wt%) were discharged into the vessel at an increased stirring speed of 2200 rpm to obtain a viscous mixture. Followed by addition of metallic salt of fatty acid in mineral oil (Dapro DF4164) (1 g, 0.1 wt%), 2,2,4-trimethylpentane-1,3-diol mono isobutyrate (10 g, 1 wt%), styrene-acrylic emulsion (306 g, 30.6 wt%), and styrene acrylic hollow latex emulsion (120 g, 12 wt%) were discharged into the vessel at 800 rpm for 15 minutes to obtain an anti-algal paint composition as represented in Table 2.
Example 4: Example 3, was repeated using 0.6 wt% of copper carbonate powder as an anti-algal additive in place of 0.3 wt%, and 14.10 wt% water in place of 14.40 wt% to obtain an anti-algal paint composition as represented in Table 2.
Table 2: Paint composition (1 kg) prepared using 0.3 and 0.6 wt% copper carbonate as an anti-algal additive
Example 3 Example 4
Ingredient Dosage (wt%) Dosage (wt%)
Water 14.40 14.10
TKPP 0.2 0.2
Ammonium salt of polyacrylic acid (Mowiplus XW330) 0.5 0.5
Nonyl phenol ethoxylate (Atsolyn A1000) 0.4 0.4
2-hydroxyethyl cellulose (HECHV) 0.4 0.4
Aqueous Ammonia 0.1 0.1
TiO2 (Rutile 902+) 21 21
aluminium silicate anhydrous (Himatex) 6 6
calcium carbonate (marble powder) 13 13
Copper Carbonate 0.3 0.6
metallic salt of fatty acid in mineral oil (Dapro DF4164) 0.1 0.1
2,2,4-trimethylpentane-1,3-diol mono isobutyrate (Texanol) 1 1
styrene acrylic hollow latex emulsion (Ultra E opaque polymer) (Opacifier) 12 12
Emulsion (film forming agent) 30.6 30.6
Total 100 100

Example 5: Experiments to evaluate the anti-algal performance of the exterior paints
The paint in accordance with the present disclosure, containing 0.3 wt%, 0.6 wt% of copper melamine or copper carbonate along with the conventional anti-algal paint containing 1% of urea based algaecide were casted on whatman filter 541 with 6 mil applicator. Subsequently, these paint films were cured in the ambient conditions for 7 days. Then, 1” × 1” portion is cut from the casted drawn preferably from the center area whereby the coating thickness is uniform. Then, 0.4 ml of algae culture inoculum (mixture of Chloralla and Oscillatoria) is placed on sterile algae culture agar petri dish (150 mm diameter petri dish containing 0.8% agarified algae culture growth medium bought from HiMedia) and spread it evenly with the help of sterile glass spreader. Now, using sterile forceps, the 1” × 1” portion of drawdown is placed with painted surface upward in the center of the petri dish and gently press to bring in complete contact with the agar surface. Now, 0.1 ml of algae culture inoculum is added and spread evenly on the drawdown paper. Now, the petri dish is incubated at ambient temperature under daylight fluorescent lamps. The progress of algae growth on paint film and in petri dish is observed every alternate day up to 14 days.
The paints in accordance with the present disclosure, at 0.3 wt% or 0.6 wt% have shown no algal growth on the paint film. Also, the conventional anti-algal paint has shown no algal growth on paint film at 1 wt% dosage. The conventional anti-algal and copper melamine complex paints of the present disclosure show full plate inhibition implying that the active biocide has leached out from paint film whereas the copper carbonate paint of the present disclosure shows no zone of inhibition implying that active biocide has not leached out of the paint film. Therefore, the copper melamine complex or copper carbonate can be used as an alternative biocide to conventional urea based algaecide. The efficacy of the copper melamine complex or copper carbonate is higher than that of conventional urea based algaecide.
Example 6: Experiment setup for outside exposure and anti algal performance study.
The paint in accordance with the present disclosure, containing 0.3 wt% and 0.6 wt% of copper carbonate were diluted by 40% with water on volume basis and thereafter, coated on concrete tiles. Concrete tiles (made of cement and sand) having smooth surface with dimensions 11.5” x 11.5” square inch were used for paint application. Coated tiles were cured for 7 days at ambient temperature and thereafter placed on exposure racks at 85-degree angle (almost vertical) before onset of rains.
The racks were kept facing South-West. The height of the tiles placed on the racks was maintained at minimum one foot above the ground. The results of the anti-algal activity of the paint compositions of the present disclosure are presented in the Table-3.
Table 3: Anti-algal activity of the anti-algal paint composition of the present disclosure in comparison with the conventional anti-algal paint composition
% algaecide in paint Anti-algal activity
Algal growth on exposure to one rainy season Algal growth on exposure to two rainy seasons Algal growth on exposure to three rainy seasons
SET I Study discontinued as the formulation paint got affected with Algae
1% conventional urea derived algaecide 0% – 10% 50% – 60%
0.3 wt.% copper carbonate 0% – 10% 40% – 50%
SET II
1% conventional urea derived algaecide 0% – 10% 50% – 60% 60% -70%
0.6 wt.% copper carbonate 0% 10% – 20% 10% – 20%

SET I:
The paint in accordance with the present disclosure, containing 0.3 wt% copper carbonate was compared against the conventional anti-algal paint containing 1 wt% of conventional urea based algaecide to evaluate on field (real world) anti-algal performance over three consecutive rainy seasons. After first rainy season, the paint of the present disclosure, has 0-10% area covered with algae which is similar to that of the conventional anti-algal paint. After second rainy season, the paint of the present disclosure, has 40-50% area spanned by algae, which is significantly lower than the conventional anti-algal paint which has 50-60% area covered by algae. However, due to high amount of algal growth on the films of paint of the present disclosure, further exposures to third rainy season was not done.
SET II:
The paint in accordance with the present disclosure, comprising 0.6 wt% copper carbonate was compared against the conventional anti-algal paint comprising 1% of conventional urea based algaecide to evaluate on field (real world) anti-algal performance over three consecutive rainy seasons. After first rainy season, the paint of the present disclosure, showed no significant algal growth but conventional anti-algal paint had 0-10% of the area covered by algae. After second rainy season, the paint of the present disclosure, with copper carbonate had 10-20% area covered by algae which is significantly lower than the conventional anti-algalpaint which had 50-60% area covered by algae. After third rainy season, paint of the present disclosure, showed no further algal growth (beyond 20%) but the conventional anti-algalpaint had 0-10% of further algal growth. The paint of the present disclosure, with 0.6% of copper carbonate had significantly lower algal growth on the paint films than the conventional anti-algal paint.
From Table 3, SET-I it is clearly observed that anti-algal paint composition of the present disclosure comprising 0.3 wt% of copper carbonate have anti-algal activity comparable to conventional anti-algal paint composition containing 1% urea based algaecide.
From Table 3, SET-II it is clearly observed that the anti-algal paint composition of the present disclosure comprising 0.6 wt% of copper carbonate has 40-50% better anti-algal activity as compared to the conventional anti-algal paint composition containing 1% urea based algaecide.
It is understood that the dried conventional paint films are porous in nature, and on coming in direct contact with water, the water loving ingredients migrate to the surface and leach out of the paint films. As a result, conventional urea based algaecides having greater solubility in water, leach out of the paint films in the presence of surfactants along with other water soluble ingredients, leading to decrease in the effective amount of these algaecide in the paint thereby resulting in higher algal growth on such conventional paint films.
On the contrary, in accordance with the present disclosure, copper carbonate and copper melamine complex, which are insoluble in continuous media i.e. water, is retained in the paint film for longer period of time. Thus, copper carbonate and copper melamine complex, even though present in lower amounts in the experimental paint as compared to the conventional urea based algaecides, show better anti-algal performance over longer duration of time than the conventional urea based algaecide for on field exposure.

Conclusion: The anti-algal paint composition of the present disclosure is:
1) Non-toxic and environment friendly, and
2) Better or comparable in anti-algal activity as compared to the conventional anti-algal paint compositions, even when used in lower amounts.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of:
? an anti-algal paint composition;
? an anti-algal paint composition which is stable and has better anti-algal properties as compared to the conventional anti-algal paint composition; and
? an easy and economical process for the preparation of the anti-algal paint composition.
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 disclosure to achieve one or more of the desired objects or results.
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 mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments 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.