FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 19 and Rule 13)
1. TITLE OF INVENTION:
PROCESS OF MAKING PAINT COMPOSITIONS USING PHOSPHATE
SLUDGE
APPLICANT(S):
KANSAI NEROLAC PAINTS LTD.,
a Company registered under the Companies Act, 1956 having address
at Nerolac House, Ganpatrao Kadam Marg, Lower Parel, Mumbai -
400 013, India.
Indian National.
3. PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the invention and the manner in which it is to be performed.
GRANTED
11-3-2008
ORGN 11 MAR 2008
181/MUM/2005

Background of Invention
For protecting iron/steel sheets from corrosion, Zinc Phosphating pretreatment process of these sheets is carried out in various Industries. Zinc phosphate pretreatment process provides a corrosion resistant base for subsequent coating films. The byproduct of this Zinc phosphating process is a Pale Yellow colored sludge. This sludge mainly comprises of Ferric Phosphate (FePO4).
The phosphating and sludge formation reaction can be explained as follows: PHOSPHATE COATING REACTION
Fe +2 H3P04 » Fe( H2P04 )2 + H2
(Substrate)
[0] oxidizer
T
FeP04 + H3PO« + V* H20 (Sludge)
H20
3Zn(H2P04)2 -> Zn3 (P04 )2.4 H20 + 4 H3P04
(Pricipal comp. (Hopeite)
of phos. Liq.)
H20
Fe + 2Zn ( H2P04 )2 -» Zn 2 Fe(P04 )2. 4 H20 +2 H3P04 + H2
(PhospHophyllite)
Currently voluminous amounts of the waste sludge are being disposed off as land fills, adding to the environmental burden,
The sludge, a product of chemical reaction, is of consistent quality. The dried sludge is cream colored, insoluble in water and most industrial solvents.
The properties of the phosphate sludge make it suitable for use in paint formulations as a Pigment / Extender / Additive / Mattening agent.
Owing to the color of the sludge, paint can be made in yellow and other shades. The sludge may be used as available or it may be treated to make it more suitable for use in paints.
The principal object of this invention is therefore to manufacture. Paint Composition from Phosphate Sludge and method of making the same. Another object of this invention is to provide a Cost effective method of preparing Paint.
Still further object is to provide different paint compositions using the Phosphate Sludge.

Accordingly, there are provided Paint Compositions comprising about 1 to 90% of Phosphate Sludge as Pigment/ Extender /Additive/ Mattening agent with water based or solvent based polymer binder, thickener, additive and suitable solvents.
A method of making the above Paint Composition based on Phosphate Sludge by mixing the Sludge in suitable proportions to give a fine stable coating dispersion in a suitable waterborne or organic solvent borne film forming medium. The sludge may be used as available or it may be treated to make it more suitable for use in Paints.
Summary of the Invention
Novel aqueous and powder coating compositions are described herein. The novelty of the invention lies in the use of waste Ferric Phosphate (FeP04) sludge obtained from metal pretreatment zinc phophating process. The disclosed coating compositions are made using the siudge as such and after treating the sludge to neutralize and dry it.
Detailed description of the invention
The sludge as such is composed of fine paste and small lumps, has a pale yellow appearance and contains phosphoric acid and water.
Aqueous coating compositions have been formulated with the sludge sample as such.
Additionally, the sludge sample may be pretreated in various ways to make it suitable for use in more different coatings compositions. The following constitutes one such process to treat the phosphate sludge. This is not exhaustive; other methods may be employed to treat the sludge.
Sludge pretreatment
Equal quantities of the sludge and deionised water was mixed. The pH of the solution is raised to pH7 by addition of Soda ash and /or triethyl amine and or sodium hydroxide and / or potassium hydroxide and / or mono ethanol amine, under constant stirring;
This neutralized mixture thus obtained is filtered with a vacuum filter. The filtrate is given at least three washings with deionised water. The resultant filtrate was dried at 105°C.
The properties of the dried sludge are as follows :

Physical properties Sludge
Appearance Cream
Solubility Insoluble in water & most industrial solvents
Volatile content 0.10%-0.5%
Specific gravity 2.60-2.90
Novel aqueous and powder coating compositions are disclosed herein, formulated using the phosphate sludge as such and after pretreatment.

The Aqueous Coating Compositions were formulated comprising Phosphate sludge 1-90%, Dispersing agent 0.5-2.00%, Emulsifier 0.01-5%, Freeze-thaw stabiliser 0-5%, Thickner 1-3%, Pigments 5-50%, Biocidal additives 0.01-20%, Adjuvants 0.01-20%, Binder 5-50%, and remaining water to make a coating composition.
The powder coating compositions were formulated comprising dry pretreated waste phosphate sludge in powder form 1-50% with resin 5-80%, matting hardener 0-10%, flow control agent 0-2%, degassing agent 0-2%, pigments 1-30%, plasticizer 0-2%, anticaking agent 0.02-2%,
Examples : The following examples A to V constitute some aqueous coating formulations based on the above experimental work. This is not an exhaustive list of the formulations made.

Paint Composition {Weight %)
RAW MATERIAL NO. A B c D E
1 10.05 5.00
2 78.00 82.60 88.52 88.00 86.06
4 2.00
7 0.50
11 0.50 2.00 2.63 1.90 2.34
12 0.50 . .
13 0.50 . .
14 - 0.50 0.50 0.50 0.50
15 0.05 . 0.05 .
16 0.20 0.20 0.20 0.20 0.20
17 0.50 0.50 0.50 0.50 0.50
18 0.50 0.50 0.50 0.50 0.50
19 0.20 0^20
20
21 1.00 0.50 0.50 0.50
22 8.00 8.00 7.00 7.00 7.00
23 0.20 0.20 0.10 0.20 0.20
Total 100.00 100.00 100.00 100.00 100.00

Paint Composition (Weight %)
RAW MATERIAL NO.. F G H I J
1 2.40 0.70 14.95 0.95 0.75
2 76.00 76.00 61.75 68.00 68.00
5 - - - 5.00 5.00
8 2.00 2.00 2.00 - -
10 - 0.25 0.25 0.25 0.25
11 1.60 0.90 0.90 0.65 0.65
12 - 0.50 0.50 0.50 0.50
14 0.50 0.50 0.50 0.50 0.50
15 - 0.05 0.05 0.05 0.05
16 0.20 0.20 0.20 0.20 0.40
17 0.50 1.00 1.00 1.00 . 1.00
18 0.90 0.50 0.50 0.50 0.50
19 0.20 0.20 0.20 0.20 - 0.20
20 - 0.50 0.50 0.50 0.50
21 0.50 . 1.50 1.50 . 1.50 1.50
22 15.00 15.00 15.00 20.00 20.00
23 0.20 0.20 0.20 0.20 0.20 .
Total 100.00 100.00 100.00 100.00 100.00

Paint Composition (VVeight%)
RAW MATERIAL NO. K L M N 0 p
1 0.65 0.65 20.20 0.45 17.20 0.50
2 68.00 68.00 48.50 68.00 52.00 68.00
5 5.00 - - - - -
6 - 5.00 5.00 5.00 5.00 5.00
7 - - - 0.10 - -
9 0.10 0.10 0.10 0.10 0.10 0.10
10 0.25 0.25 0.25 0.25 0.25 0.25
11 0.65 0.65 0.80 0.95 0.80 1.00
12 0.50 0.50 0.50 0.50 0.50 0.50
14 0.50 0.50 0.50 0.50 0.50 0.50
15 0.05 0.05 0.05 0.05 0.05 0.05
16 0.40 0.40 0.20 0.20 0.20 0.20
17 1.00 1.00 1.00 1.00 1.00 1.00
18 0.50 0.50 0.50 0.50 0.50 0.50
19 0.20 0.20 0.20 0.20 0.20 0.20
20 0.50 0.50 0.50 0.50 0.50 0.50
21 1.50 1.50 1.50 1.50 1.00 1.50
22 20.00 20.00 20.00 20.00 20.00 20.00
23 0.20 0.20 0.20 0.20 0.20 0.20
Total 100.00 100.00 100.00 100.00 100.00 100.00

Paint Composition (Weight%)
RAW MATERIAL NO. Q R S T u V
1 1.00 20.50 21.50 34.10 37.10 27.45
2 64.50 45.00 43.00 - - -
3 - - - 32.00 29.00 38.00
8 8.00 8.00 8.00 8.00 8.00 8.00
9 0.10 0.10 0.10 0.10 0.10 0.10
10 0.25 0.25 . 0.25 0.25 0.25 0.25
11 1.00 1.00 2.00 0.40 0.40 1.00
12 0.50 0.50 0.50 0.50 0.50 0.50
14 0.50 0.50 0.50 0.50 0.50 0.50
15 0.05 0.05 0.05 0.05 0.05 0.10
16 0.20 0.20 0.20 0.20 0.20 0.20
17 1.00 1.00 1.00 1.00 1.00 1.00
18 0.50 0.50 0.50 0.50 0.50 0.50
19 0.20 0.20 0.20 0.20 .0.20 0.20
20 0.50 0.50 0.50 0.50 0.50 0.50
21 1.50 1.50 1.50 1.50 1.50 1.50
22 20.00 20.00 20.00 20.00 20.00 20.00
23 0.20 0.20 0.20 0.20 0.20 0.20
Total 100.00 100.00 100.00 100.00 100.00 100.00

AQUEOUS COATING RAW MATERIALS
1 Water
2 Wet Sludge (as such)
3 Pretreated Dry Sludge
4 Synthetic Yellow oxide Pigment
5 Synthetic Red oxide Pigment
6 Synthetic Red oxide Pigment
7 Cellulosic Thickner
8 Ti02 Pigment
9 XanthanGum
10 iodo propynyl butyl carbamate, carbendazim, N'-(3,4-djchlorophenyl)-N,N-dimethyl-urea, 2-n-octyl-4-isothiazolin-3-one
11 Sodium hydroxide
12 Liquor Ammonia
13 Sodium Poly acrylate
14 Ammonium salt of Polyacrylic Acid, ammonium polyacrylate, sodium salt of Maleic acid/di-isobutylene copolymer
15 Tetra sodium pyro phosphate , Tetra potassium pyro phosphate .Sodium Hexa meta Phosphate
16, Non ionic Emulsifier (Alkyl aryl sulphonate, Nonyl phenol ethylene oxide condensate.)
17 Glycolic Freeze thaw Stabiliser
18 Dipentene
19 5-chloro-2-metyl-4-isothiazolin-3-one,2-metyl-4-isothiazolin-one 1.5%, 2-benzisothiazolin-3-one
20 Carbendazim, Octyliso thiazolinone, iodopropynyl butyl carbamate
21 Acrylic Thickner
22 Binder( polymer such as Acrylics/vinyls/styrene- acrylic/polyurethanes/ synthetic distemper binder.)
23 Silicon Based Additive .

Manufacturing Process :
Example 1
Using Pretreated Dry Sludge :
To make coating composition, Sand mill is Used.
Take a clean container. Add about 70% of the water. Add under slow speed additives like 13,14,18, emulsifier 16 , Glycolic Freeze staw stabiliser 17, 50% of Defomer 23, add 11, 12 check pH and adjust to pH7.5. Add Thickner 7,9 mix for 30 minutes. Add powder 3,4,5,6,8 and run at High speed peripheral speed of 5-18 m/sec for 30 minutes. Pass the resultant slurry through sand mill, Keep a flow rate of 200-300 Kg/hr. Check finish with appropriate addition of binder and water in small sample of slurry and then applying by brush.Cool to below 55°C add remaining ingredients under slow speed such as biocides 19,20, Binder 22, remaining Defoamer 23, thickner 21 and remaining water. Tint with appropriate colourantjf particular shade is required.
Block Diagram of the Process
Water
Slow Speed

High Speed Dispersion ( Peripheral Speed of 18 - 22 m/Sec) for 1/2 hours
Sand Mill
Flow Rate - 200 - 300 Kg/hr Cool < 55°C

Additives Biocide, Binder, Water

Slow Speed ( Peripheral Speed of 10 - 11 m/Sec) for Vi hours

Viscosity adjustment, Tinting if Required

Example 3
Using Pretreated Dry sludge :
Block Diagram of the Process

Premixer

All solid rawmaterials

150-250 RPM for 3 minutes
Holding Tank
Ext uder 100°C-130°C at a rate of 200-300 KG/hour

Chilling Belt

5°C-10°C water circulation

DCM

Mixed Flakes + Additives 5-10 minutes


Grinding to obtain powder of desired particle size

We Claim:
A process for making paint composition comprising;
(a) mixing waste phosphate sludge derived from zinc phosphating metal pretreatment, 1.00-90.00%w/w with dispersing agent 0.5-2.00 %w/w, emulsifiers 0.01-5.00% w/w, wetting agents 0.05-0.30% w/w, freeze thraw stabilizers 0- 5.00% w/w, thickners 1.00-3.00%w/w, pigments 1.00-50.00%w/w, biocidal additives 0.01-20.00%/w/w, binder 5.00-50.00%w/w, and mixing these constituents in water 0-20.00%w/w in a reactor with high speed dispersion for half an hour,
(b) grinding mixture of step (a) in sand mixer at flow rate 200-300 kg/h,
(c) cooling the mixture of step (b) below 55° C,
(d) mixing additives at slow speed for half an hour for adjusting suitable viscosity,
wherein waste phosphate sludge obtained from the zinc phosphating is used as available or after pre-treatment by mixing with equal quantity of demineralised water and neutralizing with soda ash and/or caustic soda and/or KOH and/or monoethyl amine and /or triethylamine by constant stirring, vacuum filtration followed by rinsing it with demineralised water.
2. A process for making paint composition as claimed in claim 1, wherein the dispersing agent are selected individually and / or in combination from the group consisting of Ammonium salt of Polyacrylic Acid, ammonium polyacrylate, Na salt of Maleic acid/di-isobutylene copolymer.
3. A process for making paint composition as claimed in claim 1, wherein the emulsifier are selected individually and / or in combination from the group consisting of Alkyl aryl sulphonate, Nonyl phenol ethylene oxide condensate.
4. A process for making paint composition as claimed in claim 1, wherein the Wetting Agents are selected individually and/or in combination from group

consisting of Terra sodium pyro phosphate, Tetra potassium pyro phosphate, Sodium Hexa meta Phosphate.
5. A process for making paint composition as claimed in claim 1, wherein the biocidal additives are selected individually and/or in combination from group consisting of 5-chloro-2-metyl-4-isothiazolin-3-one,2-metyl-4-isothiazolin-one 1.5%, 2-benzisothiazolin-3-one, iodo propynyl butyl carbamate, carbendazim, N'-(3,4-dichlorophenyl)-N,N-dimethyl-urea, 2-n-octyl-4-isothiazolin-3-one.
6. A process for making paint composition as claimed in claim 1, wherein the Binders are selected individually and/or in combination from group consisting of Acrylics/ vinyls/ styrene-acrylic/ polyurethanes/ synthetic distemper binder.
7. A process for making paint composition as claimed in claim 1, wherein the pretreated dry phosphate sludge in powder form is used for making useful paint compositions comprising mixing dry pretreated waste phosphate sludge in powder form 1.00-50.00% w/w with resin 5.00-80.00% w/w, matting hardener 0-10.00% w/w, flow control agent 0-2.00% w/w, degassing agent 0-2.00% w/w, pigments 1.00-30.00% w/w, plasticizer 0-2.00% w/w, anticaking agent 0.02-2.00% w/w, powder coating additives wherein the process comprises premixing all the solid raw materials in a mixer at a speed 150 to 250 r.p.m. for 3 minutes extruding through an extruder maintained at 100-130°C at a rate of 200 to 300 kg per hour and subsequently cooling the molten extrudate at 5°C-10°C and mixing of resultant flakes with anticaking agent and other additives in a mixer for 5 to 10 minutes and grinding in a grinder to obtain powder coating composition of desired particle size.
8. A process for making paint composition as claimed in claim 7 wherein the resin is selected individually and / or in combination from the group compromising

bisphenol A based epoxy resin, carboxyl terminated polyester resin, hydroxyl terminated polyester resin, glycydyl acrylics, carboxyl or hydroxyl terminated acrylics.
9. A process for making paint composition as claimed in claim 7 wherein the matting hardner is selected individually and / or in combination from the group compromising pyromellitic acid monophymyiimidazoline salt, Dicynadiamide derivatives, glycydyl acrylics.
10. A process for making paint composition as claimed in claim 7 wherein the anti-caking agent is selected individually and / or in combination from the group compromising silicon dioxide, aluminium oxide.
11. A process for making paint composition as claimed in claim 7 wherein the
additives are selected individually and / or in combination from the group
compromising Triglycidyl isocyanurate, Polyacrylate absorbed on silicon
dioxide, Bezoyl Phynyl carbinol, polyethylene tetrafluoride modified wax,
Polyethylene wax.
Dated this 16th day of February,2006.

To
The Controller of Patents,
The Patents Office, MUMBAI

VISHWANATH S HEDGE
For VISHESH & ASSOCIATES
Constituted Attorney's
For the Applicants.