COMPLETE SPECIFICATIONS
The following specification particularly describes the invention and the manner in which it is to be performed.
BIO WASTE BASED INSULATING COATING
The invention relates to paint compositions containing biological wastes preferably cow dung as one of its major constituents.
More particularly this invention relates to latex emulsion paints containing biological wastes preferably cow dung as one of its major constituents which is in a finely divided state with mean particle size of about 120 microns.
This invention also relates to exterior and interior coating or paint formulations which provide thermal insulation to homes and helps them to remain cooler in summers.
This coating uses water based polymer emulsion binder which are eco friendly and also pose no serious threat to the personnel involved in application of paint formulated with it. Both straight acrylics and styrene acrylics emulsions are used and each has its own advantages.
Acrylic latexes are generally copolymers of methyl methacrylate and any one of a number of acrylic esters. By modifying the acrylic monomers with a comparatively inexpensive monomer like styrene, the resultant latex offers an interesting balance of properties based upon its cost. As styrene is a very hydrophobic monomer, acrylic styrene latexes offer improved water resistance when compared to other latexes like PVA's and VAE's. The hydrophobicity of acrylic-styrene latexes also makes them ideal as coatings for cementitious substrates.
All acrylic polymers are chiefly composed of esters of acrylic and methacrylic acid that are polymerized by addition polymerization, usually using a free radical mechanism. The all acrylics have outstanding properties of color stability, transparency, and resistance to weathering and ageing. The good weathering resistance of acrylic polymers is due to their resistance to hydrolysis and their lack of absorption of UV light, the high energy portion of the light spectrum most responsible for degradation.
Apart from the binders several pigments and extenders enjoy a vital role in paint and coatings. White pigments include titanium dioxide (rutile and anatase), zinc oxide and opaque polymers. Extenders are low cost fillers and include talc, barytes, silica, calcium carbonate, mica etc. Apart from these there are numerous variants in colored pigments mainly classified into organic and inorganic pigments.
Additives are used to impart specific properties to the paint, to enhance stability, easier production, easier and better application etc. These include dispersing and wetting agents, defoamers, leveling agents, in-can preservatives, in-film preservatives, coalescent, rheological additives and so on.

Manufacture of almost all types of coatings begins with the grinding and dispersion of the pigments into the vehicle which is composed of the binder, solvent and certain necessary additives. Thereafter necessary adjustments are made to achieve the properties to that of the control formulation, quality checks are carried and the material is packaged for sale in the market.
Thermal insulation coatings have been explored in the past and several coatings have been developed. These were mainly based on ceramic microspheres or cenospheres but were very costly for common use. US patent 7252785 describes composition for producing a heat-insulating coating comprising of radiation-absorbing compound and IR-reflector component. Several other coatings with high reflectance have also been used to achieve thermal insulation.
It is an objective of this invention to provide water based emulsion flat paints containing finely divided cow dung as one of its extenders and which provides thermal insulation against heat.
A further objective of this invention is to provide water based emulsion fiat paints containing finely divided cow dung along with titanium dioxide and extended with calcium carbonate and barytes as fillers for improved performance properties.
A still further objective of this invention is to provide water based emulsion flat paints containing styrene-acrylic or pure acrylic emulsions as binders to achieve exceptional scrub resistance and water repellency.
Another further objective of this invention is to provide water based emulsion flat paints containing wax emulsions to increase water resistance properties and also achieve easy clean ability of the surface.
A still further objective of this invention is to provide water based emulsion flat paints containing bentonite clays along with cellulosic thickeners for improved flow, storage and application properties.
Another further objective of this invention is to provide water based emulsion flat paints which help in reducing electrical consumption in summers and also helps in reducing carbon footprint per head.
Other advantages and objects will be apparent from the following specifications and examples.
The utilization of cow dung as extender in a water based emulsion paint results in a paint with slightly darkened colour which is particularly brown and at the same time helps in achieving very good thermal insulation properties. The thermal insulation as measured by digital thermometers in prototype houses which are painted with the invented coating with respect to a blank coating containing no cow dung. However, the houses coated with cow dung based coating require one more coat of white reflective low Dry Film Thickness (DFT)

coating on it for maximum thermal insulation. Furthermore, when cow dung is used, it causes a drastic reduction in the prices of the formulated paint.
Example
Coating composition is prepared with the following ingredients:
1. Water : 430.0g
2. Dried and Pulverized Cow Dung : 240.0 g
3. Titanium dioxide : 53.2 g
4. Calcium Carbonate : 52.0 g
5. Barytes :40.0g
6. Bentonite Clay : 12.5 g
7. Styrene Acrylic Emulsion (50% solids) : 100.0 g
8. Coalescing Agent :10.0g
9. Ammonia (25% ) : 15 g
10. Dispersing Agent : 38.5 g ll.Defoamer :4.7g

12. Wax Emulsion :18.5g
13. Thickener/Protective Colloid : 4.7 g
14. Biocides/Preservatives (In-can & In-Film) : 9.6 g
Technical specifications:
1. Solids % (by weight) :49.5%
2. PVC :85%
3. pH :8.7
4. Colour : Light Brown
5. Adhesion : Excellent
6. Efflorescence Resistance : Very Good
7. Max. Temperature Difference Achieved : 5.2 °C
8. Settling after 3 months storage : Nil
9. Microbial Attack after 3 months : Nil
10. Fungal Growth on dried film : Nil (3 months external exposure)
Titanium dioxide and other extenders except cow dung are taken and added slowly under shear in a lab scale mixer to a previously prepared mixture of water, dispersing and wetting agent, defoamer and ammonia. Thereafter, this mixture is fed to a bead mill and the process of dispersion and grinding starts. The extent of grind is checked at regular intervals in a Hegman Fineness of Grind Gauge. The grinding is stopped when the grind reached a fineness of 6 on Hegman Gauge. The dispersed pigment mixture is removed and added to a beaker and mixed in a lab scale mixer. Calculated amounts of pulverized cow dung and water is added to the above and mixed in a High Speed Disperser for 15 minutes. This preparation is called mill base and is thus ready for further processing.

Styrene-Acrylic or Pure Acrylic Emulsion, water and other additives like coalescent, defoamer, preservatives, and thickener are added and taken in a beaker and mixed to uniformity. This is called letdown. Mill base is them added slowly to the let down under mixing at low RPM to uniformity.
This paint is then applied on a prototype house of internal dimensions of 1 foot length, breadth and height and 1 inch wall thickness. The prototype house is made of a mixture of sand and cement. Thereafter a low DFT white coat id applied over it to increase its reflectivity. Another prototype house in made of the same dimensions and the same wall thickness is made and a blank coating which contains no cow dung is applied which is also white in colour and the total DFT is also the same in both the prototype houses. Internal air temperature is measured at various times during the day over a number of days and the difference between the internal air temperatures of the two prototype houses is recorded. The maximum temperature difference that is achieved is termed as Maximum Temperature Diffemece Achieved.
Though the properties of cow dung in styrene acrylic emulsion system has been given in one formulation only, it is intended that this example be representative of the classes of paints described and useful in exterior, interior and interior-exterior applications which can utilize cow dung as an extender as it incorporates easily under sufficient shear. The foregoing example is illustrative only and additional modifications may be made without departing from the substance of the invention as defined in the appended claims.

We Claim:
1. A method of preparing water borne coating composition, containing at least 20 % by
weight dried pulverized cow dung of mean particle size 120 microns and which
provides thermal insulation against heat when applied as exterior coating.
2. The composition described in Claim 1 wherein the cow dung percentage is on weight basis.
3. The composition described in Claim 1 wherein the inocorporated cow dung provides thermal insulation against heat.
4. Method as claimed in Claim 1 wherein the dispersing agent is a sodium polyacrylate.
5. Method as claimed in Claim 1 wherein wax emulsion is based on polyethylene wax.
polypropylene wax or polytetrafluoroethylene wax.
6. Method as claimed in Claim 1 wherein defoamer consists of a preparation of a
mixture of modified polysiloxanes.
7. Method as claimed in Claim 1 wherein defoamer consists of a preparation of a
mixture of mineral oils.
8. Method as claimed in Claim 1 wherein the coalescent is propanoic acid-2-methyl-
monoester with 2,2,4-trimethyl-l,3-pentanediol.
9. Method as claimed in Claim 1 wherein the biocide is a blend of chlorinated and non-
chlorinated isothiazolones.
10. Method as claimed in Claim 1 wherein the thickener consists of Hydroxy Ethyl Cellulose, HASE (Hydrophobically modified Alkali Swellable Emulsion), HEUR (Hydrophobically modified Ethoxylated Polyurethane) or Carboxy Methyl Cellulose.