FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. TITLE OF THE INVENTION:
"A cement paint composition"
2. APPLICANT (S)
(a) NAME: MALSHE VINOD CHINTAMANI
(b)NATIONALITY: Indian
(c) ADDRESS: 1, Staff Quarters, UDCT Campus, Matunga, Mumbai - 400 019, Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.



1 9 SEP 2005

Technical filed of invention:
The present invention relates to paint and in particular to cement paint with good resistance properties.
Background of the invention:
Any major city has full of high rise buildings, mostly designed by good architects with great care. The exterior of these buildings are not abler to retain their beauty beyond certain years. Either they have developed large streaks algae which completely destroy the aesthetic beauty or the plaster develops serious cracks which lead to leakage of water through the walls which need to be plugged with elastomeric coatings and makes the exterior looks of such buildings are pathetic. Some prestigious structures in Mumbai were painted with two coats of epoxy and one coat of polyurethane. These showed considerable resistance to weathering, algae, sea breeze, corrosion of reinforcement etc. The typical life of the product was found to be about 5 years after which it was repainted. The cost of this painting was in excess of Rs. 30 /- per sq. ft.
In most cases, housing societies can not afford such a high cost of painting. Prior art reports following conventional painting system for exterior:
• Co-polymer of the styrene / butadiene and vinyl toluene / acrylate types. These are latex or in solution form, when suitably pigmented produce films which adhere well to the various substrates and show very good durability;
• Combination of drying oils and alkyds;
• Epoxy esters offer good durability;
• Emulsions of vinyl co-polymers in which the second monomer can be ethylene or an acrylic ester. Terpolymer solutions produced from vinyl chloride, vinyl acetate, are claimed to possess very good weather resistance;
• Acrylic emulsions are used in a similar manner. They have greater durability;
• Cement paints, which are supplied in the form of dry powder and are mixed with water prior to use.

Most commonly cement based paints are used. Plenty of white cement is available. When slurry of white cement in water is used to paint the exterior wall, it form hard film but suffered from algae resistance and poor barrier properties which reduces its life. The cost of painting is one of the lowest and is also practiced in "Do it yourself category.
Malshe and co-worker worked on cheap exterior paint with good resistance to algae growth and resistance to water leakage and reported in Paint India (2000), 48. The cement paint comprises a white cement, emulsion as a binder, algaecides, inorganic pigment and water. The main problem of cement paint is porosity of film. It was partially overcome by incorporation of emulsion, which are a dispersion of discrete flexible polymeric particles in water. It is know that the cement grains hydrate only when they are surrounded by membrane of water. However, the water membrane now contains polymer particles which gradually come together to form a film on the surface of the hydrates as the water becomes chemically bound. Emulsions provide to primary requirements to the cement film: one is adhesion and low shrinkage.
Although the cement paints are suitable for protection and decoration of porous building walls by giving matt finish and improving the resistance to leakage, but they are facing major problem, efflorescence. The lime content in the cement paint is the main cause of efflorescence.
Efflorescence is the leaching of lime, leading to formation of salts deposits on the painted surface. During monsoon, water percolates the surface and hydrolyzes the lime to form calcium hydroxide solution. This solution migrates to the surface and evaporates leaving behind the solid calcium hydroxide. This calcium hydroxide then reacts with surface carbon dioxide (air) to form calcium carbonate.
CaO + H20 > Ca(OH)2


Ca(OH)2 4 CO2 > CaC03 + H20
Thus calcium carbonate forms either hazy white layers or thick crusts on the surface, thus spoiling the decoration of surface. They give chalking effect. These white patches of calcium carbonate can easily be washed away by rainy water, thus, losing the opacity. As the time passes the cement paint layer loses all its hiding power, leaving behind patches all over the surface.
Dr. L. T. Gangotri and L. S. Mhaske reported cement paint containing no hydrated lime to overcome the problem of efflorescence in Paintindia (2004), 41.They have reduced the quantity of cement in the paint composition by replacing it with cheaper whiting, red oxide and titanium dioxide pigments.
Developments still needed/ drawbacks
Cement paints available till date have several drawbacks as follows :
• Hiding is not adequate; and
• Efflorescence, which causes white spotting and surface becomes dull.
Object of invention:
It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide useful alternative.
It is an object of the invention in its preferred form to provide a cement paint, which has good hiding power and does not show efflorescence effect.

Another object of the present invention is to provide a cement paint composition comprising a chemical entity which reacts with lime, thus avoiding reaction with atmospheric carbon dioxide.
Summary of the invention:
According to the present invention there is provided a cement paint composition, which are supplied in the form of dry powder and mixed with water prior to use.
According to the invention there is provides a cement paint comprising component A; component B and component C.
Component A is pure white cement.
Component B comprises hiding pigment, coloring pigment, binder, wetting agent, dispersing agent, biocides and a lime reactive extender etc.
Component C comprises complexing agent to bind calcium hydroxide or any chemical entity which reacts with freshly generated lime, not allow lime to come above the surface coat of paint and product thus formed will become part of the film.
Detailed description:
The present invention discloses Cement paint with good resistance properties.
According to the present invention there is provided cement paint composition, which are supplied in the form of dry powder and mixed with water prior to use.
One of the embodiments according to the present invention provides cement paint composition comprising component A; component B and component C.

Component A is pure white cement.
Component B comprises hiding pigment, coloring pigment, binder, wetting agent, dispersing agent, biocides and a lime reactive extender etc.
Component C comprises complexing agent to bind calcium hydroxide or any chemical entity which reacts with freshly generated lime, not allow lime to come above the surface coat of paint and product formed will become part of the film.
Hiding pigments are selected from Titanium dioxide and zinc oxide either alone or in combination thereof or low grades of enriched ilmenite containing various concentrations of iron thus limiting its use to yellow shades and yellow tolerant shades.
The concentration of hiding pigment is in the range of 5 to 40 w/w % of total composition.
Coloring pigments is either inorganic pigment or organic pigment. The concentration of the coloring pigments is 1 to 10 % wt/ wt of total composition.
The binder used in the composition is a polymeric emulsions. The emulsions may be selected from acrylic emulsion, acrylic/styrene emulsion, styrene butadiene emulsion, styrene vinyl toluene emulsion, ethylene vinyl acetate or any emulsion, which can form film at room temperature and resist alkaline environment generated by hydration of cement.
The concentration of binder in the present invention is 4 to 40 % wt/wt of the total composition.
Wetting agents are selected from sulfonated melamine formaldehyde, sulfonated naphthalene formaldehyde, sodium or ammonium poly acrylate, partially hydrolysed poly acrylamide of low or medium molecular weight

The concentration of wetting agent in the present cement paint composition is 0.1 to 5 % wt/ wt of the total composition depending on the particle size of the pigments and extenders.
Dispersing agents are selected from sulfonated melamine formaldehyde, sulfonated naphthalene formaldehyde, sodium or ammonium poly acrylate, partially hydrolysed poly acrylamide of low or medium molecular weight The dispersing agent used in the present composition is in the range of 0.1 to 5%
Extenders are selected from calcite, precipitated calcium carbonate, china clay, whiting, finely ground quartz, barites or precipitated barium sulfate, dolomite, feldspar, wollstonite, or any other white or slightly coloured mineral or processed mineral substantially insoluble in water including industrial waste products such as calcium fluoride, calcium carbonate or the like.
Extenders are used in the range of 0 to 100 parts of the total pigment composition.
Component C comprises calcium chloride, magnesium chloride, and diethyl oxalate, reactive silica obtained from any source, silica obtained from Ferro silicone process, ground glass either individually or in combination thereof precipitated silica, calcined silica alumina, active silica, ground silica gel, rice husk ash, precipitated alumina which has alkaline reaction.
Component C is added in the composition up to 50 % wt/wt of the total composition. The cement liberates approximately 30% lime of its own weight. The purpose is to allow this lime to react and precipitate this lime in an insoluble form that does not emerge on the surface and allow formation of a thin film of calcium carbonate. The quantity of these substances is adjusted as per their capability to react with lime.
Biocides are selected such that it should be stable at highly alkaline condition. The biocides used are methyl benzimidazol-2-ylcarbamate, 3-iodo-2-propynyl butyl

carbamate, 2-n-octyl-4-isothiazolin-3-one, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea, 2-tert-butylamino-4-cyclopropyl amino-6-methylthio-l,3,5-triazine, 2,4,5,6-tetrachlroiso phthalonitrile, etc either alone or combination thereof, the biocides used in the range of 0.1 to 1% individually or in combination. The selection is based on the humidity of the area.
Humectants such as magnesium oxy chloride diethylene glycol, glycerol, sorbotol is added to the composition for retaining water in the film for little longer time.
One aspect of the present invention is to provide the cement paint in three separate containers comprising component A, component B and component C respectively. At the application site, cement paint is prepared by the following process: component A is mixed with water to make a slurry. Component B is added to this slurry and finally component C is added to the above mixture of component A and B slurry to get the cement paint. The hemectant is added optionally at any stage of the process. The mix has approximately 2 hrs. potlife and is applied either by a spray or brush.
The present invention will now be further illustrated by the following example, which does not limit the scope of the invention in any way.

Example Example 1
Cement paint composition

Sr. No. Ingredient Quantity (wt/wt)
A White cement 1000.0

B Ti02 50
Fe203 (red) 10
Acrylate emulsion 80
Wetting agent 1.2
Dispersing agent 2.0
Extender 200

C MgCl2 (30% in water) 150

Example 2
Cement paint composition

Sr. No. Ingredient Quantity (wt/wt)
A White cement 1000.0

B Zn02 10
Ti02 40
Organic pigment 5.0
Emulsion 80
Wetting agent 1.5
Dispersing agent 3.5
Extender 500

C Reactive silica 200

I claim,
1. A cement paint composition comprising component A, component B and component C in the form of dry powder, wherein said component A comprises pure white cement, component B comprises hiding pigment, coloring pigment, binder, wetting agent, dispersing agent, biocides and a lime reactive extender and component C comprises a complexing agent.
2. A cement paint composition as claimed in claim 1 wherein, said hiding pigment is selected from Titanium dioxide and zinc oxide either alone or in combination thereof or low grades of enriched ilmenite containing various concentrations of iron in the concentration range of 5 to 40 w/w % of total composition.
3. A cement paint composition as claimed in claim 1 wherein, said colouring pigment is either inorganic or organic pigment in the concentration range of 1-10%w/w of total composition.
4. A cement paint composition as claimed in claim 1 wherein, said binder is a polymeric emulsion selected from acrylic emulsion, acrylic/styrene emulsion, styrene butadiene emulsion, styrene vinyl toluene emulsion, ethylene vinyl acetate or any emulsion, which can form film at room temperature and resist alkaline environment generated by hydration of cement in the concentration range of 4 to 40 % w/w of the total composition.
5. A cement paint composition as claimed in claim 1 wherein, said wetting agent and/or dispersing agent is selected from sulfonated melamine formaldehyde, sulfonated naphthalene formaldehyde, sodium or ammonium poly acrylate, partially hydrolysed poly acrylamide of low or medium molecular weight in the concentration range of 0.1 to 5 % w/ w of the total composition
6. A cement paint composition as claimed in claim 1 wherein, said extenders are selected from calcite, precipitated calcium carbonate, china clay, whiting, finely ground quartz, barites or precipitated barium sulfate, dolomite, feldspar, wollstonite, or any other white or slightly coloured mineral or processed mineral substantially insoluble in water including industrial waste products such as calcium fluoride and calcium carbonate used in the range of 0 to 100 parts of the total pigment composition.

7. A cement paint composition as claimed in claim 1 wherein, said biocide is selected from methyl benzimidazol-2-ylcarbamate, 3-iodo-2-propynyl butyl carbamate, 2-n-octyl-4-isothiazolin-3-one, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea, 2-tert-butylamino-4-cyclopropyl amino-6-methylthio-l,3,5-triazine and 2,4,5,6-tetrachlroiso phthalonitrile either alone or combination thereof used in the range of 0.1 to 1%.
8. A cement paint composition as claimed in claim 1 wherein, said component C comprises calcium chloride, magnesium chloride, and diethyl oxalate, reactive silica obtained from any source, silica obtained from Ferro silicone process, ground glass either individually or in combination thereof precipitated silica, calcined silica alumina, active silica, ground silica gel, rice husk ash, precipitated alumina which has alkaline reaction in the concentration of upto 50 % wt/wt of the total composition.
9. A cement paint composition as claimed in claim 1 wherein, said composition is prepared by a process comprising: Mixing component A with water to make a slurry; adding Component B to this slurry; and adding component C to the above mixture of component A and B to get the cement paint and optionally adding humectant selected from oxy chloride diethylene glycol, glycerol, sorbitol at any stage of the process.
10. A cement paint composition as substantially described herein with reference to the foregoing examples 1 and 2.

Dr. Gopakumar G. Nair
Agent for the Applicant
Dated this the 13th day of September 2005