DESC:FIELD
The present disclosure relates to a clear coat composition and a process of its preparation. Particularly, the present disclosure relates to a water based clear coat composition with self-cleaning and air purifying performance.
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 indicates otherwise.
DPUR: The term “DPUR” stands for dust pick up resistance property of a coating, which refers to the coating that resists the dirt pick up on the coated substrates.
Delta E (DE): Delta E is a standard measurement created by the International Commission on Illumination that quantifies the difference between two colors that appear on a screen. Delta E is measured on a scale from 0 to 100, where 0 is less color difference, and 100 indicates complete distortion.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Buildings and other architectural structures/constructions are constantly exposed to dirt and air pollution. There are lot of challenges for maintenance of cleanliness of the exterior surfaces of the buildings and other architectural structures. Further, the chemicals present in the environment wear away the materials of the exterior surfaces of the buildings such as sandstone, limestone, mortar, and the like. Furthermore, the acid rain dissolves stone and can create cracks in the buildings and other architectural structures/constructions. It is very expensive to repair such damages of architectural structures/constructions. Currently, there are few coating products existing in the market which address the dirt pick up resistance or having good dirt cleanability. However, these products do not address the problems associated with the pollution aspect. Further, these conventional products do not have self-cleaning property specifically for dirt cleaning. Moreover, the conventional coating products do not provide an efficient solution for the problems altogether.
There is, therefore, felt a need to develop a clear coat composition that mitigates the drawbacks mentioned herein above or at least provides a useful alternative.
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 background or to at least provide a useful alternative.
An object of the present disclosure is to provide a clear coat composition.
Another object of the present disclosure is to provide a clear coat composition having self-cleaning property.
Still another object of the present disclosure is to provide a clear coat composition having air purifying performance for architectural exteriors.
Yet another object of the present disclosure is to provide a clear coat composition that enables reduction of nitrogen dioxide gas and sulfur dioxide gas from the environment.
Still another object of the present disclosure is to provide a clear coat composition that has long term durability and sustained performance
Yet another object of the present disclosure is to provide a clear coat composition having no negative impact on the substrate after application.
Still another object of the present disclosure is to provide a simple and an environment friendly process for the preparation of a clear coat 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 clear coat composition comprising at least one colloidal silica; a rheology modifying agent; a surface conductivity improving agent; a coupling agent; an UV light responsive toner; additives; and water.
In an embodiment of the present disclosure, the clear coat composition comprises 5 mass% to 60 mass% of the colloidal silica; 0.1 mass% to 2 mass% of the rheology modifying agent; 0.01 mass% to 2 mass% of the surface conductivity improving agent; 0.1 mass% to 2 mass% of the coupling agent; 0.1 mass% to 2 mass% of the UV light responsive toner; 0.01 mass% to 8 mass% of the additives; and q.s. water, wherein the mass% of each ingredient is with respect to the total mass of the composition.
The additive is selected from a leveling agent, a surfactant, a preservative, and an UV absorber.
Further, the present disclosure relates to a process for the preparation of a clear coat composition. The process comprises mixing a predetermined amount of a rheology modifying agent in water under stirring for a time period in the range of 5 minutes to 30 minutes followed by adding a predetermined amount of a preservative under stirring for a time period in the range of 2 minutes to 15 minutes to obtain a first mixture. A predetermined amount of a surface conductivity improving agent is added to the first mixture under stirring for a time period in the range of 5 minutes to 15 minutes followed by adding predetermined amounts of a surfactant, a leveling agent and a coupling agent under stirring for a time period in the range of 5 minutes to 15 minutes to obtain a second mixture. Predetermined amounts of colloidal silica, UV absorber, UV light responsive toner are added to the second mixture under stirring for a time period in the range of 5 minutes to 15 minutes to obtain the clear coat composition.
The rheology modifying agent is lithium sodium magnesium silicate.
The preservative is a composition of chlormethyl-/methylisothiazolone and formaldehyde (Rocima 623).
The surface conductivity improving agent is single wall carbon nanotubes (Tuball coat E H2O).
The surfactant is at least one selected from the group consisting of anionic fluorosurfactants and ethoxylated nonionic fluorosurfactants.
The leveling agent is polysiloxane in ethylene glycol n-butyl ether solvent.
The coupling agent is an epoxy functional silane oligomer.
The colloidal silica has an average particle size in the range of 2 nm to 12 nm.
The UV absorber is a blend of UV absorber and hindered amine light stabilizers (HALS) (Tinuvin 5333-DW ECO).
The UV light responsive toner is a dyed/pigmented polyester resin.
The colloidal silica is selected from copper metal adsorbed on the colloidal silica substrate (PREBONA® odorcontrol TC), silver along with traces of copper and zinc adsorbed on the colloidal silica substrate (Prebona Combifresh), an aqueous dispersion of colloidal silica (Levasil CC-301) and a combination thereof.
The predetermined amount of
• the rheology modifying agent is in the range of 0.1 mass% to 2 mass%;
• the preservative is in the range of 0.05 mass% to 2 mass%;
• the surface conductivity improving agent is in the range of 0.01 mass% to 2 mass%;
• the surfactant is in the range of 0.01 mass% to 2 mass%;
• the leveling agent is in the range of 0.01 mass% to 2 mass%;
• the coupling agent is in the range of 0.1 mass% to 2 mass%;
• the colloidal silica is in the range of 5 mass% to 60 mass%;
• the UV absorber is in the range of 0.1 mass% to 2 mass%; and
• the UV light responsive toner is in the range of 0.1 mass% to 2 mass%,
wherein the mass% of each ingredient is with respect to total mass of the composition.
In an embodiment of the present disclosure, the surface conductivity improving agent is a dispersed surface conductivity improving agent, wherein the dispersed surface conductivity improving agent is prepared by mixing a predetermined amount of a dispersing agent in water under stirring for a time period in the range of 2 minutes to 10 minutes, followed by adding a predetermined amount of a surface conductivity improving agent under stirring for a time period in the range of 5 minutes to 20 minutes.
In accordance with the embodiment of the present disclosure, the dispersing agent is sodium dodecyl benzene sulfonates.
The predetermined amount of the dispersing agent is in the range of 0.01 mass% to 1 mass% with respect to the total mass of the composition.
In an embodiment of the present disclosure, throughout the process, the stirring is done at a speed in the range of 200 rpm to 700 rpm.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 (A) illustrates the relative DPUR performance of the clear coat composition of Example 1 Vs control;
Figure 1(B) illustrates the relative DPUR performance of the clear coat composition of Example 2 Vs control;
Figure 2 illustrates the relative mud stain cleanability performance of the clear coat composition of (A) Example 1, (B) Example 2 and (C) control (commercial premium exterior emulsion paint);
Figure 3(A) illustrates the test chamber with continuous water showering arrangement;
Figure 3 (B-C) illustrates the sustained cleanability performance of (B) the clear coat composition of Example 1 and (C) control (commercial premium exterior emulsion paint);
Figure 4 illustrates QUV-B exposed test panels for (a) control (LHS) and (b) with the clear coat composition of the present disclosure;
Figure 5 illustrates protection of dark shades by clear coat composition of the present disclosure Vs control (A) before and (B) after cleaning;
Figure 6 illustrates (A) Experimental set up for measuring the electrical conductivity in EXP1 and EXP2 VS control and (B) Surface resistance (electrical conductivity) Vs SWCNT concentration in EXP1 sample;
Figure 7 illustrates a laboratory set up for measuring the Air-cleaning Performance (NO2 and SO2 absorption), wherein (A) illustrates Air quality measurement device from Oizom, (B) Test set up with closed glass chamber with test panel and equipment;
Figure 8 illustrates the graphical representations showing the relative NO2 and SO2 absorption in EXP1 and EXP2 VS Control, wherein (A) illustrates NO2 reduction by EXP1 and EXP2 VS control; (B) illustrates SO2 reduction by EXP1 and EXP2 Vs Control; and (C) illustrates NO2 reduction by increased SWCNTs in EXP1;
Figure 9 illustrates the SEM images demonstrating differences in cracking in (A) EXP1 Vs (B) Control (commercial clear coat without colloidal silica composition);
Figure 10 illustrates (A) Initial application of emulsion paint and emulsion paint with EXP1 immediately after application; (B) application of emulsion paint and emulsion paint with EXP1 after 45 days of natural exposure; (C) application of emulsion paint and emulsion paint with EXP1 after 180 days of natural exposure; at Bangladesh trial site; (D) 6 months outdoor exposure of Emulsion paint (without EXP 1) and Emulsion Paint (with EXP 1) at Nepal trial site; and
Figure 11 illustrates the emulsion paint with experimental clear coat (emulsion paint + EXP 1 on RHS) showed no dirt / water mark after 8 months exposure at Indonesia trial site.
DETAILED DESCRIPTION
The present disclosure relates to a clear coat composition and a process of its preparation. Particularly, the present disclosure relates to a water based clear coat composition with self-cleaning and air purifying performance.
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.
Buildings and other architectural structures/constructions are constantly exposed to dirt and air pollution. There are lot of challenges for maintenance of cleanliness of the exterior surfaces of the buildings and other architectural structures. Further, the chemicals present in the environment wear away the materials of the exterior surfaces of the buildings such as sandstone, limestone, mortar, and the like. Furthermore, the acid rain dissolves stone and can create cracks in the buildings and other architectural structures/constructions. It is very expensive to repair such damages of architectural structures/constructions. Currently, there are few coating products existing in the market which address the dirt pick up resistance or having good dirt cleanability. However, these products do not address the problems associated with the pollution aspect. Further, these conventional products do not have self-cleaning property specifically for dirt cleaning. Moreover, the conventional coating products do not provide an efficient solution for the problems altogether.
The present disclosure provides a clear coat composition and a process of its preparation. Particularly, the present disclosure relates to a water based clear coat composition with self-cleaning and air purifying performance.
In an aspect, the present disclosure provides a clear coat composition.
The clear coat composition comprises:
a) at least one colloidal silica;
b) a rheology modifying agent;
c) a surface conductivity improving agent;
d) a coupling agent;
e) an UV light responsive toner;
f) additives; and
g) water.
In accordance with an embodiment of the present disclosure, the clear coat composition comprises
a) 5 mass% to 60 mass% of the colloidal silica;
b) 0.1 mass% to 2 mass% of the rheology modifying agent;
c) 0.01 mass% to 2 mass% of the surface conductivity improving agent;
d) 0.1 mass% to 2 mass% of the coupling agent;
e) 0.1 mass% to 2 mass% of the UV light responsive toner;
f) 0.01 mass% to 8 mass% of the additives; and
g) q.s. water,
wherein the mass% of each ingredient is with respect to the total mass of the composition.
The colloidal silica has an average particle size in the range of 2 nm to 12 nm.
In an embodiment of the present disclosure, the colloidal silica is selected from copper metal adsorbed on the colloidal silica substrate (PREBONA® odorcontrol TC), silver along with traces of copper and zinc adsorbed on the colloidal silica substrate (Prebona Combifresh), an aqueous dispersion of colloidal silica (Levasil CC-301) and a combination thereof. In an exemplary embodiment of the present disclosure, the colloidal silica is a combination of PREBONA® odorcontrol TC and Levasil CC-301.
In an embodiment of the present disclosure, Levasil CC301 has the average particle size in the range of 7 nm to 10 nm and PREBONA® odorcontrol TC has the average particle size in the range of 2 nm to 5 nm.
Prebona odor control TC is a colloidal dispersion of spherical amorphous silica in water. The surface of the silica particles is modified to reduce odor by effectively removing the odor molecules from the surrounding air by catalytic conversion of odor causing molecules and converting it into the less odor causing molecules. Hence, the Prebona odor control TC is considered as a catalytic odor absorbing material. The colloidal silica particles with copper actives are used for air purifying performance and cleanability. The active content in Prebona odor control TC is 5%.
Prebona Combifresh is a colloidal dispersion of spherical amorphous silica in water. In the dry form, Prebona Combifresh irreversibly forms a macroscopic and durable three dimensional structure that adheres well to treated surfaces. It contains active silver along with traces of copper and zinc. Prebond Combinfresh reduces odor effectively and is a broad spectrum disinfectant with sustained antimicrobial effect against bacteria, virus and fungi.
Levasil CC-301 is an aqueous dispersion of colloidal silica surface modified with hydroxyl groups. Levasil CC-301 provides surface hydrophilicity and surface hardness.
The rheology modifying agent is lithium sodium magnesium silicate (Laponite RD -Na0.7 Si8 Mg5.5 Li0.3 O20 (OH)4)).
Laponite RD is a synthetic layered silicate. Further, Laponite RD, Levasil CC-301 and Prebona Odor control TC, when used in a specific ratio, imparts a crack free and crack resistant durable clear film. The layered silicate synergizes the crack resistance and rheology for improved sag resistance when applied on vertical surfaces.
Conventionally known rheology modifying agents such as organo clays are not equivalent in terms of their performance. Moreover, Laponite RD provides the dispersing action for SWCNTs. It is observed that the shelf stability of the clear coat composition fails if Laponite RD is not used.
The surface conductivity improving agent is single wall carbon nanotubes (Tuball coat E H2O).
In an embodiment of the present disclosure, the surface conductivity improving agent is dispersed in a dispersing medium, wherein the dispersing medium is a mixture of a dispersing agent and water.
The dispersing agent is sodium dodecyl benzene sulfonates (Rhodacal DS-10).
Laponite RD also acts simultaneously as a dispersing agent for the SWCNT (single wall carbon nano tubes- surface conductivity improving agent) to keep them in dispersed state during the storage period. It shows very good synergy with sodium dodecyl benzene sulfonates to stabilize the SWCNTs.
Tuball coat E H2O 0.4% (OCSiAl) is a nano dispersion of the SWCNT (single wall carbon nano tubes) used for the purpose of increasing the surface conductivity or reducing the surface resistivity. The single walled carbon nanotubes (TUBALL™ COAT_E H2O 0.4%) are used to facilitate crack resistance in the film along with the increase in surface conductivity and hence, enables the radio frequency (RF) shielding and electromagnetic interference (EMI) shielding.
The coupling agent is epoxy functional silane oligomer(CoatOSil MP 400 Epoxy Silane).
CoatOSil MP 400 Epoxy Silane reacts with silica surface and prevents crack formation.
The UV light responsive toner is a dyed/pigmented polyester resin (STX 09).
The UV light responsive toner is used for the traceability of the clear coat application specifically when applied on the white/pastel painted surfaces or sufaces where clear coat is not visible with the necked eyes.
The additives are selected from the group consisting of a leveling agent, a surfactant, a preservative, and an UV absorber.
The preservative is a composition of chlormethyl-/methylisothiazolone and formaldehyde (Rocima 623).
The surfactant is at least one selected from the group consisting of anionic fluorosurfactant (Capstone FS-93) and ethoxylated nonionic fluorosurfactant (Capstone FS 30). In an exemplary embodiment of the present disclosure, the surfactant is Capstone FS 30
Capstone™ FS-30 is a water-soluble, ethoxylated nonionic fluorosurfactants composition, wherein the composition is 25% solids in water. Capstone™ FS-93 is a water-soluble, anionic fluorosurfactant composition, wherein the composition is 17% solids and 20% isopropyl alcohol.
The leveling agent is polysiloxane in ethylene glycol n-butyl ether solvent (PATADD LE 1030).
The UV absorber is a blend of UV absorber and hindered amine light stabilizers (HALS) (Tinuvin 5333-DW ECO).
The clear coat composition of the present disclosure is applied on masonary, stucco, bricks, plaster, concrete, both painted and not painted substrates and the like by the conventional methods of paint application such as by using brush, roller, spray and the like. The clear coat composition of the present disclosure protects the substrate/painted substrate from dry dirt deposition and help cleanability of the accumulated dirt by simple water cleansing or wind driven rain. The clear coat composition thus facilitates the sustained clean look which is free of dirt streak marks and soiling of the building. Further, the clear coat composition of the present disclosure enables the substrate with good cleanability of wet mud stains, good crack resistance that are observed on the exteriors of the building walls. Furthermore, the clear coat composition enables the application on vertical walls without sagging and enables the reduction of toxic gases such as nitrogen dioxide (NO2), sulphur dioxide (SO2) and the like from the environment.
In another aspect, the present disclosure provides a process for the preparation of a clear coat composition.
The process comprising the following steps:
a. mixing a predetermined amount of a rheology modifying agent in water under stirring for a time period in the range of 5 minutes to 30 minutes followed by adding a predetermined amount of a preservative under stirring for a time period in the range of 2 minutes to 15 minutes to obtain a first mixture;
b. adding a predetermined amount of a surface conductivity improving agent to the first mixture under stirring for a time period in the range of 5 minutes to 15 minutes followed by adding predetermined amounts of a surfactant, a leveling agent and a coupling agent under stirring for a time period in the range of 5 minutes to 15 minutes to obtain a second mixture; and
c. adding predetermined amounts of colloidal silica, UV absorber, UV light responsive toner to the second mixture under stirring for a time period in the range of 5 minutes to 15 minutes to obtain the clear coat composition.
The rheology modifying agent is lithium sodium magnesium silicate (Laponite RD -Na0.7 Si8 Mg5.5 Li0.3 O20 (OH)4)).
The preservative is a composition of chlormethyl-/methylisothiazolone and formaldehyde (Rocima 623).
The surface conductivity improving agent is single wall carbon nanotubes (Tuball coat E H2O).
In an embodiment of the present disclosure, the surface conductivity improving agent is a dispersed surface conductivity improving agent, wherein the dispersed surface conductivity improving agent is prepared by mixing a predetermined amount of a dispersing agent in water under stirring for a time period in the range of 2 minutes to 10 minutes, followed by adding a predetermined amount of a surface conductivity improving agent under stirring for a time period in the range of 5 minutes to 20 minutes.
In accordance with the embodiment of the present disclosure, the dispersing agent is sodium dodecyl benzene sulfonates (Rhodacal DS-10).
The predetermined amount of the dispersing agent is in the range of 0.01 mass% to 1 mass% with respect to the total mass of the composition.
The surfactant is at least one selected from the group consisting of anionic fluorosurfactant (Capstone FS-93) and ethoxylated nonionic fluorosurfactant (Capstone FS 30). In an exemplary embodiment of the present disclosure, the surfactant is Capstone FS 30.
The leveling agent is polysiloxane in ethylene glycol n-butyl ether solvent (PATADD LE 1030).
The coupling agent is epoxy functional silane oligomer (CoatOSil MP 400 Epoxy Silane).
The colloidal silica has an average particle size in the range of 2 nm to 12 nm.
In an embodiment of the present disclosure, the colloidal silica is selected from copper metal adsorbed on the colloidal silica substrate (PREBONA® odorcontrol TC), silver along with traces of copper and zinc adsorbed on the colloidal silica substrate (Prebona Combifresh), an aqueous dispersion of colloidal silica (Levasil CC-301) and a combination thereof. In an exemplary embodiment of the present disclosure, the colloidal silica is a combination of PREBONA® odorcontrol TC and Levasil CC-301.
In an embodiment of the present disclosure, Levasil CC301 has the average particle size in the range of 7 nm to 10 nm and PREBONA® odorcontrol TC has the average particle size in the range of 2 nm to 5 nm.
The UV absorber is a blend of UV absorber and hindered amine light stabilizers (HALS) (Tinuvin 5333-DW ECO).
The UV light responsive toner is a dyed/pigmented polyester resin (STX 09).
The predetermined amount of
• the rheology modifying agent is in the range of 0.1 mass% to 2 mass%;
• the preservative is in the range of 0.05 mass% to 2 mass%;
• the surface conductivity improving agent is in the range of 0.01 mass% to 2 mass%;
• the surfactant is in the range of 0.01 mass% to 2 mass%;
• the leveling agent is in the range of 0.01 mass% to 2 mass%;
• the coupling agent is in the range of 0.1 mass% to 2 mass%;
• the colloidal silica is in the range of 5 mass% to 60 mass%;
• the UV absorber is in the range of 0.1 mass% to 2 mass%; and
• the UV light responsive toner is in the range of 0.1 mass% to 2 mass%,
wherein the mass% of each ingredient is with respect to total mass of the composition.
In an embodiment of the present disclosure, throughout the process, the stirring is done at a speed in the range of 200 rpm to 500 rpm. In an exemplary embodiment of the present disclosure, the stirring speed is 300 rpm. In another exemplary embodiment of the present disclosure, the stirring speed is 400 rpm.
The process for the preparation of the clear coat composition in accordance with the present disclosure is simple, economic and is convenient for industrial scale-up.
The clear coat composition of the present disclosure is used in exterior applications with the following key benefits:
• self-cleaning performance: the clear coat composition has good dirt pick up resistance-DPUR;
• removal of toxic chemicals (air purifying): the clear coat composition has an air purifying property by removing the typical toxic substances present in the indoor air such as SOx and NOx;
• long term durability and sustained performance;
• mud stain resistance and good cleananility; and
• good crack resistance.
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 purposes 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: Preparation of the clear coat composition in accordance with the present disclosure
Example 1: In 1500 ml vessel equipped with stirring arrangement, 663.5 g of water was added followed by adding 7.5 g of Laponite RD (rheology modifying agent) under stirring at 500 rpm for 15 minutes and then 2 g Rocima 623 (preservative) was added under stirring and stirred for 5 minutes to obtain a first mixture.
Preparation of dispersed Tuball coat E H2O (surface conductivity improving agent): In a separate 250 ml vessel with stirring arrangement, 163.5 g of water and 0.5 g of Rhodacal DS-10 (dispersing agent) were added under stirring at 300 rpm and stirred for 5 minutes followed by adding 1 g of Tuball coat E H2O (0.4%) (surface conductivity improving agent) and continued stirring for 10 minutes to obtain a transparent dispersed Tuball coat E H2O.
The so obtained transparent dispersed Tuball coat E H2O was added to the first mixture under stirring at 400 rpm for 7 minutes followed by adding 3.5 g Capstone FS30 (surfactant), 2 g PAT-ADD-LE-1030 (leveling agent) and 5 g Coatosil MP 400 (coupling agent) and stirring was continued at 400 rpm and stirred for 10 minutes to obtain a second mixture. 100 g Levasil CC 301, 200 g Prebona Odor control TC, 10 g Tinuvin 5333-DW ECO (UV absorber) and 5 g STX 09 (UV light responsive toner) were added to the second mixture under stirring at 400 rpm and stirred for 10 minutes to obtain the clear coat composition.
Example 2: The clear coat composition was prepared by following the same procedure as in Example 1 by varying the amounts of the ingredients as shown in table 1.
Table 1: Amounts of the ingredients used in Example 1 and Example 2
Sr.No. Ingredients Chemical composition Example 1 (mass %) Example 2 (mass %)
1 Water 66.35 46.35
2 Rocima 623 A composition of chlormethyl-/methylisothiazolone
and formaldehyde 0.2 0.2
3 Rhodacal DS-10 sodium dodecyl benzene sulfonates 0.05 0.05
4 Tuball coat E H2O 0.4% single wall carbon nanotubes 0.1 0.1
5 Laponite RD lithium sodium magnesium silicate 0.75 0.75
6 Capstone FS30 ethoxylated nonionic fluorosurfactant 0.35 0.35
7 PAT-ADD- LE- 1030 olysiloxane in ethylene glycol n-butyl ether solvent 0.2 0.2
8 Coatosil MP 400 epoxy functional silane oligomer 0.5 0.5
9 Levasil CC 301 an aqueous dispersion of colloidal silica 10 10
10 Prebona Odor control TC copper metal adsorbed on the colloidal silica substrate 20 40
11 Tinuvin 5333- DW ECO a blend of UV absorber and hindered amine light stabilizers 1.00 1.00
12 STX 09 UV light responsive toner dyed/pigmented polyester resin 0.5 0.5

Experiment 2: Physicochemical properties of the clear coat compositions prepared in Experiment 1
The physical properties of the clear coat composition prepared in Example 1 and Example 2 were tested at 30 °C by using the standard test methods. Specific gravity, pH, viscosity, surface tension, appearance of the clear coat composition were measured and the results are summarized in Table 2. The ease of application was studied by using conventional brush, roller and spray application tools. The results are tabulated in Table 2.
The sheen was evaluated on the small size panels (6 inch X 3 inch size) along with control by using glossometer at 60 degree head.
Table 2: Physicochemical properties of the clear coat compositions of Example 1 and Example 2
sr. no. Properties Example 1 Example 2
1 Specific gravity@ 30 °C 1.01 1.01
2 Viscosity@ 30 °C by Stormer viscometer (KU) 48.6 49.8
3 pH @ 30 °C 8.4 8.4
4 Surface tension as such (m N/m) 29.91 30.37
5 Incan appearance (Visual) Translucent/ Transparent greyish viscus liquid Translucent/ Transparent greyish viscous liquid
6 Consistency (Visual) Viscous liquid Viscous liquid
7 Ease of application Easy to apply by brush/ roller/ spray Easy to apply by brush/ roller/ spray
8 Application Method used Brush Application Brush Application
9 Sheen@60-degree head by glossometer 14.2 6.0
Experiment 3: Performance Evaluation of the clear coat compositions prepared in Experiment 1
For evaluating the performance properties, the below application protocol was used for test panel preparation
Preparation of the test panels and test methods used:
The cement composite test panels were applied with the commercial premium quality emulsion paint in two coats (second coat was applied after 4 hours drying interval) followed by one coat of the clear coat composition prepared in Experiment 1 (after 4 hours of drying of the emulsion aint) over it. These test panels were allowed to cure for 7 days and then the following properties were measured using the standard test methods.
Similarly, the standard size cement composite panels (6 inch X 3 inch size) were also prepared as above to evaluate the water contact angle and Di-iodomethane contact angle along with control. These test panels were also used for studying the long term durability by exposing these test panels in QUV B test chamber and Atlas weatherometer for 500 hours.
Water contact angle for the clear coat composition of Example 1 is 25 and for Example 2, it is 27 and di-iodomethane contact angle is 56 for Example 1 and 55 for Example 2.
The conventional paints of god quality generally have a high water contact angle in the range of 60 to 70 which indicates hydrophobicity of the coat on the walls i.e. more water repelling property. Thus, higher the water contact angle, less is the wettability of the coat. For exterior wall, the coating is required to have good wettability by water so that the dirt on the walls can be easily washed away. As the water contact angle of the clear coat composition of the present disclosure is in the range of 25 to 27 (which is significantly lesser as compared to the conventional paints) which indicates hydrophilicity of the coat, the coat on the exterior walls will have a good wettability by water, thus, the dirt on the exterior walls can be easily washed away.
A. Dirt pick up resistance (DPUR) :
DPUR was assessed by using the large test panels (1 sq. ft). The test panels were exposed horizontally on high dust prone areas for one month and the degree of soiling was compared and rated visually on the scale R= 1 to R= 10 (1 is very poor and 10 being the best performance). Figure 1(A) illustrates the relative DPUR performance of the clear coat composition of Example 1 Vs control and Figure 1(B) illustrates the relative DPUR performance of the clear coat composition of Example 2 Vs control. The clear coat composition of both the Examples 1 and 2 showed significantly better performance than the control, the ratings are expressed in Table 4. These test panels were subsequently cleaned with normal water spray to assess the cleanability. The clear coat composition of both the Examples 1 and 2 showed very good cleanability as compared to the control. The results are shown in Table 4.
B. Mud stain cleanability performance:
Mud stain cleanability performance was assessed using large test panels (1 sq. ft) with red mud solution. The solution of red garden mud (prepared with the ratio of 70:30 wt% Mud: Water) was applied on test panel using handheld brush and kept for drying overnight (24 hours). The red mud mark was then washed using normal water spray bottle till all the loose mud came off. The degree of cleaning of the mud mark was then assessed comparatively with the commercial premium exterior emulsion paint. Degree of red mud adhesion on the panel was compared and rated visually on the scale R=1 to R=10 (1 is very poor and 10 being the best performance). The results are summarized in Table 4. Figure 2 illustrates the relative mud stain cleanability performance of the clear coat composition of (A) Example 1, (B) Example 2 and (C) control (commercial premium exterior emulsion paint).
C. Sustained cleanability performance:
To assess the long term / sustained cleaning performance of the mud stain, the coated test panels were exposed to continuous water showers for 8 days (192 hours). Figure 3(A) illustrates the test chamber with continuous water showering arrangement. Subsequently, these panels were dried at room temperature (28 °C) for 24 hrs. The mud stains were then applied uniformly on these test panels along with the control and allowed them to dry for further 24 hours. The dried mud stains were then cleaned using normal water spray (using household spray bottle) and the retention of the mud stain marks on the test panels were observed to ascertain the mud stain cleanability. The test panels were then compared and rated visually on the scale R=1 to R=10 (1 is very poor and 10 being the best performance). This test was done to ensure water resistance of the coat and sustained long term performance in high rain prone areas. It is evident from the results that, the clear coat composition of the present disclosure showed significantly better mud stain cleanability even after the exposure to rain, thus proving sustained performance in simulated weather condition, specifically in continued rain. The rating of the cleanability is given in Table 4. Figure 3 (B to C) illustrate the sustained cleanability performance of the (B) clear coat composition of Example 1 and (C) control (commercial premium exterior emulsion paint).
D. Accelerated weathering by QUV-B Resistance Test:
Cement fibre board panel of size 6 X 3 inches were coated with a premium emulsion paint. After curing of the paint, the clear coat composition of Example 1 was applied on the cured panel using brush and allowed for 7 days curing. Control (without clear coat) and experimental (with clear coat) panels were kept in Q-lab QUV-B test chamber (with 313 nm wavelength) and exposed to UV light for 1500 hours. The change in the appearance and color was noticed and measured as delta E value (DE value). Lower the DE value, better is the stability. The results are tabulated in Table 3. Figure 4 illustrates QUV-B exposed test panels for control (LHS) and with clear coat (RHS).
Table 3: DE value (represents the change in appearance on exposure to QUV B test condition) for control and the clear coat composition of Example 1
Sr. No. Panel Description DE value
1 Control (emulsion paint with no clear coat) 2.5
2 With clear coat composition of Example 1 1.004
The conventional clear coats become yellow overtime when exposed to exterior weathering condition specifically UV light which was tested here and confirmed through QUV B exposure study. The results of Delta E value near 1 shows minimum difference after exposure and thus, shows no impact on the color that is underneath the clear coat. This proves that the clear coat comnposition of the present disclosure has no negative impact on the underneath color when this clear coat is applied over the exterior paints.
E. Application of the clear coat composition on Dark Shades:
As there are increment in the Street Art segments and various other application of dark shades on exterior walls and structures, there is a need to protect such dark and bright shades from soiling which is caused due to external factors such as sunlight, dust, and the like. By using the water based clear coat composition of the present disclosure, the durability and lifetime of the shade can be enhanced and thus the sustained clean look can be maintained. Dark and bright shades became resistant to dirt and non-yellowing when the clear coat was applied over them.
This is evident from Figure 5, wherein it is clearly illustrated that the dark shades (left side of the Figure 5) coated by the clear coat composition of Example 1 when exposed to open environment for 12 months, shows resistance from dirt and dust. On the other hand, the right side portion of the dark shades without coating of the clear coat composition after 12 months exposure to open environment shows a layer of dirt and dust on it.
F. Electrical Conductivity:
The test panels to assess the electrical conductivity of the clear coat compositions of the present disclosure were prepared by first applying the ESD (electro-static dissipative) primer followed by application of the clear coat composition of Example 1 (EXP 1) and cured for 48 hours. The cured panels were evaluated for the electrical conductivity by ESD meter where the electrical resistance was measured in Ohms and expressed as relative conductivity. The set up is as illustrated in Figure 6(A). The results are given in Table 4. The results are compared with conductive range 104 to 109 ohms to assess if the experimental sets are qualifying for the classification (conductive/ dissipative/ insulating) and also with resistivity range 103 to 105 ohms. It can be conclude from the data shown in Figure 6(B) that by introducing 0.02 % of the SWCNTs the coat becomes ESD class (16000 ohm), which can take care of the static charge related performance when applied over the relevant surface. While 0.04 % SWCNT based coat demonstrated very good conductivity (3960 ohm) which indicates good surface resistivity. This enables the applications requiring RF or EMI shielding coatings.
ESD coatings refer to the electro static dissipative coatings. By the addition of the SWCNTs in the clear coat composition of the present disclosure the clear coat has an anti-static property as shown in terms of the relative conductivity.
G. Air cleaning performance (NO2 and SO2 absorption):
Air cleaning performance was tested on large panels (1 sq. ft) coated with premium exterior emulsion paint white followed by application of one coat of the clear coat composition of Example 1/ Example 2. The panels were cured for 7 days and then tested for their relative NO2 and SO2 absorption performance in a close chamber equipped with the air quality measurement device. The known amount of the test gases (NO2 and SO2) were injected in a closed glass chamber having the air quality measurement device (Oizom).
Figure 7 illustrates a laboratory set up for measuring the Air-cleaning Performance (NO2 and SO2 absorption), wherein (A) illustrates Air quality measurement device from Oizom, (B) Test set up with closed glass chamber with test panel and equipment. Figure 8 illustrates the graphical representations showing the relative NO2 and SO2 absorption in EXP1 and EXP2 VS Control, wherein (A) illustrates NO2 reduction by EXP1 and EXP2 VS control; (B) illustrates SO2 reduction by EXP1 and EXP2 Vs Control; and (C) illustrates NO2 reduction by increased SWCNTs in EXP1.
The reduction of the test gases at each 5 minutes interval were measured and recorded to ascertain the relative performance of the toxic gas absorption, wherein the % reduction in NO2 and SO2 are given in Table 4. The results demonstrate very good air quality performance of the clear coat composition of the present disclosure Vs control.
H. Film crack resistance:
The clear coat composition of the present disclosure are based on inorganic components such as colloidal silicas and the key risk of using such inorganic components is that the film may crack due to internal stresses generated in the film, hence this study was specifically carried out to ascertain crack free film by testing the test samples for film crack resistance. Film cracking resistance was studied using SEM analysis. A black leneta PVC panel was used on which the commercial premium exterior emulsion paint was applied using 150-micron wet film applicator. The panel was kept for curing overnight and then experimental clear coats (along with control coat i.e. commercial clear coat without colloidal silica composition) were applied using fine paint brush for smooth application. Panels were allowed to cure for 7 days. These panels were then cut into small pieces and carried out the SEM analysis. The observations were made on crack resistance based on the crack size, crack segment size surface smoothness and the like. Figure 9 illustrates the SEM images demonstrating differences in cracking in (A) clear coat composition of Example 1 Vs (B) Control (commercial clear coat without colloidal silica composition). The clear coat composition of the present disclosure does not include any organic binder. The mechanical and other performances of the clear coat composition of the present disclosure are based on the close packing of the colloidal silica of varied sizes. When compared with the commercial clear coat using the similar chemistry, it is observed in SEM images that the clear coat composition of the present disclosure does not show any crack whereas the control showed the cracks. This confirms no cracking behaviour and a good coherent of the clear coat composition of the present disclosure.
Table 4: Performance properties of the clear coat composition of Examples 1 and 2 against Control (the commercial premium exterior emulsion Paint)
Sr. no. Properties Clear coat composition Control: Commercial Premium Exterior emulsion paint
Eample 1 Example 2
1 *Dirt Pickup resistance – DPUR (1 month Natural Exposure) Visual Rating 1 to 10 scale 8 8 4
2 *Dirt cleanability Performance ( Visual Rating 1 to 10 scale) 8.5 8 4
3 *Mud Cleanability 8 7 3
4 *Mud cleanability after shower test (8 days) 7 6 3
5 QUV B exposure 15 days (DE Values) 1.004 4.652 2.5
6 Electrical Conductivity(ohm) 2.16*1010 2.16*1010 Out of range ( No evidence of conductivity)
7 NO2 Reduction 15% 45% 0%
8 SO2 Reduction 10% 23% 0%
* scale R= 1 to R= 10 (1 is very poor and 10 being the best performance)
I. Anti- algal performance:
Anti- algal performance was determined by using anti-algal chamber test method in which the clear coat composition applied small panels (4X3 inch) were kept in algal induced chamber with continuous flow of water. Table 5 depicts the rating of the anti- algal performance for experimental test panels Vs control (Scale 0 (poor performance) to 10 (best performance)). There was no any negative performance by the application of the clear coat composition over the paint as seen from the results.
Table 5: Anti- algal performance of the Example 1, Example 2 and Control (Premium exterior emulsion paint)
S. No. Sample Description Antialgal performance rating
1 Control 5
2 Example 1 5
3 Example 2 5
Experiment 4: Field Trials at various Sites namely Nepal, Bangladesh, Srilanka, Indonesia
Samples of the clear coat composition of Example 1 were sent to various trial sites. Two Exterior patches of dimensions 6x2 sqft each were applied first with Exterior waterbased primer and subsequently with two top coats of Emulsion paint after which the clear coat composition of Example 1 was applied as a single coat by roller on 1 exterior patch as shown in the Figure 10 and observed with time.
Figure 10 illustrates (A) Initial application of the emulsion paint and the emulsion paint with the clear coat composition of Example 1 (herein after referred as EXP 1) immediately after application; (B) application of the emulsion paint and the emulsion paint with EXP 1 after 45 days of natural exposure; (C) application of the emulsion paint and the emulsion paint with EXP 1 after 180 days of natural exposure at Bangladesh trial site; (D) 6 months outdoor exposure of Emulsion paint (without EXP 1) and Emulsion Paint (with EXP 1) at Nepal trial site.
Figure 11 illustrates the emulsion paint with the clear coat composition of Example 1 (emulsion paint + EXP 1 on RHS) showed no dirt / water mark after 8 months exposure at Indonesia trial site.
Conclusion: Water based clear coat composition of the present disclosure has the self-cleaning (for the dirt/ mudstains) and air purifying (NO2 and SO2) performances for architectural exterior application. The use of the colloidal silica demonstrated the sustained performances such as : 1) Ease of application on variety of substrates and specifically for the protection of certain specific painted surfaces (elastomeric paints / coatings prone to very high soiling tendencies. 2) Best dirt pick up resistance and dirt cleanability by water washing 3) Mud stain cleanability 4) crack resistance 5) electrical conductivity and hence potential use as ESD (electro-static dissipative) coating/ RF- EMI shielding coatings and when applied in exteriors it does not negatively affect the anti- algal performance of the underneath paint.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of;
? a clear coat composition that:
• has self-cleaning property;
• has air purifying/cleaning property for reducing sulphur dioxide (SO2) gas and nitrogen dioxide (NO2) gas;
• has long term durability and sustained performance; and
? a process for the preparation of a clear coat composition that is simple and economic.
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 object 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. ,CLAIMS:WE CLAIM:
1. A clear coat composition comprising:
a. at least one colloidal silica;
b. a rheology modifying agent;
c. a surface conductivity improving agent;
d. a coupling agent;
e. an UV light responsive toner;
f. additives; and
g. water.
2. The composition as claimed in claim 1 comprising:
a. 5 mass% to 60 mass% of said colloidal silica;
b. 0.1 mass% to 2 mass% of said rheology modifying agent;
c. 0.01 mass% to 2 mass% of said surface conductivity improving agent;
d. 0.1 mass% to 2 mass% of said coupling agent;
e. 0.1 mass% to 2 mass% of said UV light responsive toner;
f. 0.01 mass% to 8 mass% of said additives; and
g. q.s. water,
wherein said mass% of each ingredient is with respect to the total mass of said composition.
3. The composition as claimed in claim 1, wherein said additives are selected from a leveling agent, a surfactant, a preservative, and an UV absorber.
4. The composition as claimed in claim 1, wherein said colloidal silica is selected from copper metal adsorbed on the colloidal silica substrate, silver along with traces of copper and zinc adsorbed on the colloidal silica substrate, an aqueous dispersion of colloidal silica and a combination thereof; and
wherein said colloidal silica has an average particle size in the range of 2 nm to 12 nm.
5. The composition as claimed in claim 1, wherein said rheology modifying agent is lithium sodium magnesium silicate.
6. The composition as claimed in claim 1, wherein said surface conductivity improving agent is single wall carbon nanotubes.
7. The composition as claimed in claim 1, wherein said surface conductivity improving agent is dispersed in a dispersing medium,
wherein said dispersing medium is a mixture of a dispersing agent and water.
8. The composition as claimed in claim 6, wherein said dispersing agent is sodium dodecyl benzene sulfonates.
9. The composition as claimed in claim 1, wherein said coupling agent is epoxy functional silane oligomer.
10. The composition as claimed in claim 1, wherein said UV light responsive toner is a dyed/pigmented polyester resin.
11. The composition as claimed in claim 3, wherein
• said leveling agent is polysiloxane in ethylene glycol n-butyl ether solvent;
• said preservative is a composition of chlormethyl-/methylisothiazolone and formaldehyde;
• said surfactant is at least one selected from the group consisting of anionic fluorosurfactants and ethoxylated nonionic fluorosurfactants; and
• said UV absorber is a blend of UV absorber and hindered amine light stabilizers (HALS).
12. A process for the preparation a clear coat composition, said process comprising the following steps:
a. mixing a predetermined amount of a rheology modifying agent in water under stirring for a time period in the range of 5 minutes to 30 minutes followed by adding a predetermined amount of a preservative under stirring for a time period in the range of 2 minutes to 15 minutes to obtain a first mixture;
b. adding a predetermined amount of a surface conductivity improving agent to said first mixture under stirring for a time period in the range of 5 minutes to 15 minutes followed by adding predetermined amounts of a surfactant, a leveling agent and a coupling agent under stirring for a time period in the range of 5 minutes to 15 minutes to obtain a second mixture; and
c. adding predetermined amounts of a colloidal silica, an UV absorber, an UV light responsive toner to said second mixture under stirring for a time period in the range of 5 minutes to 15 minutes to obtain said clear coat composition.
13. The process as claimed in claim 12, wherein said rheology modifying agent is lithium sodium magnesium silicate.
14. The process as claimed in claim 12, wherein said preservative is a composition of chlormethyl-/methylisothiazolone and formaldehyde.
15. The process as claimed in claim 12, wherein said surface conductivity improving agent is single wall carbon nanotubes.
16. The process as claimed in claim 12, wherein said surfactant is at least one selected from the group consisting of anionic fluorosurfactants and ethoxylated nonionic fluorosurfactants.
17. The process as claimed in claim 12, wherein said leveling agent is polysiloxane in ethylene glycol n-butyl ether solvent.
18. The process as claimed in claim 12, wherein said coupling agent is epoxy functional silane oligomer.
19. The process as claimed in claim 12, wherein said colloidal silica has an average particle size in the range of 2 nm to 12nm.
20. The process as claimed in claim 12, wherein said UV absorber is a blend of UV absorber and hindered amine light stabilizers (HALS).
21. The process as claimed in claim 12, wherein said UV light responsive toner is dyed/pigmented polyester resin.
22. The process as claimed in claim 12, wherein said colloidal silica is selected from copper metal adsorbed on the colloidal silica substrate, silver along with traces of copper and zinc adsorbed on the colloidal silica substrate, an aqueous dispersion of colloidal silica and a combination thereof.
23. The process as claimed in claim 12, wherein said predetermined amount of
• said rheology modifying agent is in the range of 0.1 mass% to 2 mass%;
• said preservative is in the range of 0.05 mass% to 2 mass%;
• said surface conductivity improving agent is in the range of 0.01 mass% to 2 mass%;
• said surfactant is in the range of 0.01 mass% to 2 mass%;
• said leveling agent is in the range of 0.01 mass% to 2 mass%;
• said coupling agent is in the range of 0.1 mass% to 2 mass%;
• said colloidal silica is in the range of 5 mass% to 60 mass%;
• said UV absorber is in the range of 0.1 mass% to 2 mass%;
• said UV light responsive toner is in the range of 0.1 mass% to 2 mass%,
wherein said mass% of each ingredient is with respect to total mass of said composition.
24. The process as claimed in claim 12, wherein said surface conductivity improving agent is a dispersed surface conductivity improving agent,
wherein said dispersed surface conductivity improving agent is prepared by mixing a predetermined amount of a dispersing agent in water under stirring for a time period in the range of 2 minutes to 10 minutes, followed by adding a predetermined amount of a surface conductivity improving agent under stirring for a time period in the range of 5 minutes to 20 minutes.
25. The process as claimed in claim 24, wherein said dispersing agent is sodium dodecyl benzene sulfonates.
26. The process as claimed in claim 24, wherein said predetermined amount of said dispersing agent is in the range of 0.01 mass% to 1 mass% with respect to the total mass of said composition.
27. The process as claimed in claims 12 and 24, wherein said stirring is done at a speed in the range of 200 rpm to 500 rpm.
Dated this 20th day of March, 2024

_______________________________
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