FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
“QUICK AIR DRY PAINT FOR CHASSIS FRAME PAINTING”
Name and Address of the Applicant: TATA MOTORS LIMITED of Bombay house, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001, Maharashtra, INDIA.
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION:
The present disclosure relates to the field of paint/coating composition that can be applied to a substrate. Mainly, the disclosure relates to quick air dry paint/coating composition for the chassis frame of an automobile. The present invention specifically relates to a coating composition comprising the combination of three resin systems in combination with zirconium catalyst having quick drying properties. Further, it provides a method of preparing the same and applying such paints/coatings.
BACKGROUND OF THE INVENTION:
A number of coating compositions are in the market to coat different parts of an automobile. Multi¬layer coatings are applied to a wide variety of substrates to provide color and other visual effects, corrosion resistance, abrasion resistance, chemical resistance. Multi-layer coatings generally comprise of a basecoat layer that provides visual effects and a topcoat layer that provides an abrasion and scratch resistant layer. With respect to multi-layer coatings, a primer layer may also included. It is desirable to provide top coatings that provide low cure temperatures and a less drying time.
The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s).
AU2007350580B2 discloses a method for preparing paints and/or inks in which a particle composition consisting of pigment dyestuff, an aldehyde, ketone and/or acrylic resin and optionally excipients and/or adjuvants are mixed into at least one organic solvent, water or a mixture thereof. The invention also relates to paints and/or inks obtainable using said preparation method and to manufactured items painted and/or treated with such paints and/or inks.
EP0796904A3 relates to a thermosetting resin or coating composition contains (a) a film-forming polyol resin, (b) a curing agent reactive with the polyol resin, (c) a hydrolyzate/polycondensate of tri- or tetraalkoxysilane, and (d) a catalyst for promoting the reaction between the polyol resin (a) and the curing agent (b).

CN115260849A relates to acrylic resin insulating paint and it’s method of preparation and application in the field of paint. The insulating paint is prepared from using thermoplastic acrylic resin, epoxy modified acrylic resin, silicon resin and a cosolvent. Main body film-forming resin is thermoplastic acrylic resin, epoxy modified acrylic resin and silicon resin; the thermoplastic acrylic resin has good quick-drying performance and is beneficial to improving the surface drying performance of the insulating paint; the epoxy modified acrylic resin has water resistance and chemical resistance, so that the water resistance of the insulating paint is improved; the silicon resin has the properties of hydrophobicity, moisture resistance, good electrical insulation and the like; silicon resin is selected, so that the insulating property of the paint film can be improved; meanwhile, the cosolvent provides a reaction place for interaction between the resins; meanwhile, the viscosity of the acrylic resin insulating paint can be reduced; therefore, the leveling property of the insulating paint is improved, and a uniform paint film is formed.
However, generally coating composition for chassis painting takes much time to dry specially when very little solvent is present, it is difficult to produce a paint which will dry rapidly. Therefore, there is a need to develop a quick air dry coating composition.
Another benefit of choosing a good air drying coating composition is that the quality of work will improve. A quick drying coating composition will be able to dry the paint evenly and at optimal temperatures, thus reducing the chances of bubbles, streaks, or runny paint that results in a finished product.
Frame is the backbone of vehicle on which the entire aggregate and load body is mounted. Chassis frame is made up of two long members and various cross members. One side of chassis are exposed towards the ambient atmosphere during vehicle running on the roads and on other side load body is mounted. Before the load body is mounted, the chassis frames are exposed to sunlight and it requires the outdoor durability in terms of ultraviolet resistance, impact resistance, paint film hardness etc. To achieve these properties till the time medium and heavy commercial vehicle (M&HCV) industry uses the top-coat paints with baking window of 110 degree Celsius for 15 minutes. The present disclosure is about innovative air-dry topcoat paint for Chassis frame structure, which will eliminate the baking process.
The known prior arts provide different kinds of topcoats for different kind of base coat on the chassis frame in the prior arts. The present disclosure is directed to overcome one or more

drawbacks by providing one topcoat over the multiple base coats on the chassis frame which requires less time to dry.
SUMMARY OF THE INVENITON
The main objective of the present disclosure is of environment sustainability of getting 100 % renewable energy in manufacturing operation in automobile industry by 2030. As the various rules and regulations are coming in force to eliminate the carbon intensive processes or to convert it towards greener energy for carbon reduction. The chassis frame coating is major energy intensive process having cons of more than 7 kg/Eq. This painting process with baking oven was running from last several years. There is continuous research to evolve some innovative process for baking oven elimination in the top-coat painting to achieve the environmental sustainability goal. With this disclosure, the inventors are able to eliminate the carbon footprint generation in the range of 80-100 tCO2 eq./month. The inventors are able to achieve carbon footprint reduction and process cost reduction (variable conversion cost) of the top-coat painting process for chassis frame.
The aim of the present disclosure is to provide a coating composition comprising the combination of three resin systems in combination with zirconium catalyst. The present invention specifically relates to providing one topcoat over the multiple base coats on the chassis frame.
In another aspect of the present invention the paint for topcoat is a black paint comprising acrylic resin. The acrylic resin can be of thermosetting acrylic and/or thermoplastic acrylic. Further, the composition comprises ketonic resin and silicon resin. In this composition, carbon black is added as filler or pigment. For filler, barium sulphate is added. Solvent can be selected from xylene, and/or ketonic solvents, depending on weather conditions and other factors. Further additives are selected from anti sagging agents, anti-settling agents, dispersing agents and Tinuvin UV additives. Zirconium or strontium catalyst is also added in the said composition.
In another aspect of the present invention the coating composition comprises:
• an acrylate alkyd resin in an amount of 27 wt.% to 32 wt. %.
• a thermoplastic acrylic resin in an amount of 8 wt.% to 10 wt. %.
• a silicon resin in an amount of 4 wt.% to 5 wt. %.
• a ketonic resin in an amount of 5 wt.% to 6 wt. %; and
• a zirconium catalyst in an amount of 0.5 wt.% to 0.6 wt.%

• a filler or extender in an amount of 34.4 wt % -45.5 wt.%; and
• and thinner in an amount of 10-12% based on total weight of the coating composition.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiments when read in conjunction with the accompanying figures.
Figure-1 illustrates photograph of adhesion test results on various substrate.
DETAILED DESCRIPTION OF THE INVENTION
While the disclosure is susceptible to various modifications and alternative forms, specific aspects thereof have been described in detail below. It should be understood, however, that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention.
The present disclosure relates to a coating composition comprising the combination of three resin systems in combination with zirconium catalyst. The present invention specifically relates to providing one topcoat over the multiple base coats on the chassis frame. In an aspect of the present invention the component of paint includes:

Components in Paint Volume %
Acrylic Resin 27-32%
Thermoplastic Acrylic Resin 8-10%
Silicon Resin 4-5%
Ketonic Resin 5-6%
Zirconium 0.5-0.6 %
additives 34.5-45.4%
Solvents 10-12%

In another aspect of the present invention acrylic resin is a polymeric form of different acrylic monomers. Usually esters of acrylic, methacrylic acids or their derivatives like methyl methacrylate, butyl acrylate etc. are used as monomers and combined to form a polymer as resin using free radical polymerization technique.
In another aspect of the present invention the resin used gives good weathering resistance and other chemical resistance. It is used as main constituent in the range of 27-32 volume % of the Topcoat paint providing the characteristic properties of a topcoat paint.
Acrylic Polymer Acrylic Resin
In one of the embodiment, the coating composition, wherein the acrylic resin is a polymer of monomer units selected from methyl methacrylate (MMA) and Butyl Methacrylate (BMA) monomer for modified acrylic or acrylated alkyd resin having molecular weight of 40000-50000.

In yet another embodiment, the coating composition, wherein thermoplastic acrylic resin is styrene and butyl acrylate monomers or combination thereof having molecular weight of 80000-90000.
In another aspect of the present invention the thermoplastic acrylic is one type of acrylic resin and is used as a component of top-coat paint.
In an embodiment of the present invention wherein the acrylic resin is selected from methyl methacrylate resin, butyl acrylate resin, etc. Acrylic resin is divided into two categories-thermosetting acrylic and thermoplastic acrylic. The thermosetting acrylics are heat cured and can easily be combined with epoxy or melamine or amino to form hard coating in presence of temperature while thermoplastic acrylics are cured by oxidative self-polymerization using their free radicals.
Thermoplastic resins can be prepared by polymerization of methyl methacrylate, styrene like monomer. Thermoplastic resins has good drying property, chemical resistance properties and adhesion properties. Thermoplastic acrylics form polymer film by self-oxidative polymerization while thermosetting acrylic resin forms polymeric film through a cross link with amino or amine or epoxy.
Thermoplastic acrylics can cure in ambient temperature with the presence of sufficient air or oxygen while thermosetting needs temperature.
The present disclosure used this resin in the range of 8-10% to enhance quick drying properties and adhesion on metal surfaces. Also, to avoid belt mark while frame lifting with belt, this resin dries quickly and produce a hard surface after 20-40 minutes.
In an embodiment of the present invention the thermoplastic acrylic resin is selected from polymer made from monomer units of methyl methacrylate, styrene etc.
Thermoplastic Acrylic Resin

Methyl Methacrylate

Styrene

Poly Methyl Methacrylate Styrenated (Hard, Brittle in nature)
The coating film-forming component preferably contains a thermoplastic resin. By including the thermoplastic resin, the fluidity of the coating composition can be adjusted.
In an aspect of the present invention silicon resins are based on an inorganic silicon and oxygen structure with organic radical attachments. Silicon oxygen and silicon carbon bond are stable and for that it is resistant to thermal oxidation and decomposition. Silane or silanols react with each other at hydroxyl groups or oxygen radical to form polymeric structure of silicon resin.
In an embodiment of the present invention the silicon resin is selected from methyl tri-ethoxy silicone resin, octamethyl cyclo tetra siloxane, or combination thereof.

Methyl Trietoxy Silane
Octa Methyl cyclo terra siloxane
Polymer formation (Resin)

Siloxane Prepolymer
Silicon Resin

In another aspect of the present invention silicon resins comprises 4-5 volume% of the topcoat paint to get hard compact surface for attaining good water, chemical and weathering resistance.
In another aspect of the present invention the Ketonic Resins used are prepared with ketone like cyclohexanone and aldehyde.
In another aspect of the present invention the aldehydes include paraformaldehyde in the presence of an simple alkali, wherein the simple alkali used is sodium hydroxide.
In another aspect of the present invention the presence of ketonic resin improves paint finish and hardness, enhances paint levelling and wetting properties that impact paint adhesion.
The present invention comprises 5-6 volume% of the ketonic resin in the topcoat paint resulting in improved paint wetting and levelling on multiple substrates present in the frame.
In yet another aspect of the present invention the presence of ketonic resins helps in improved adhesion properties on powder coating.
In another aspect of the present invention when powder coated long members are made to dissolve in ketonic solvents. The paint obtained is further applied with ketonic resin. The ketonic solvents

present in the resin; wet or dissolve micro layer of powder coated surface and fuse in that molten interface resulting in improved adhesion properties.
In the present disclosure, oxidative polymerization method evolved with combination of resin systems (acrylic (27-32-%) + thermoplastic acrylic (8-10%) + ketonic (5- 6%) + silicon (4-5%) with zirconium catalyst.
Evaluation of paint/coating composition:
Paint Adhesion Properties on Multiple Base coat painting system-Nano coating + cathodic electro-deposition (CED), powder coating, zinc plating, 2K Epoxy and acrylated alkyd base coat painting system compatibility explored and validated with above resin system with several design of experiment (DOE) and iterations.
Water resistance properties (At several times environmental conditions changes and quick dry painted frames are exposed towards rain water within 60 minutes of painting interval) – silicon resin (4-5%) which had excellent water repellent properties is added in paint formulation which is an value addition to the paint.
Frame stack handling & transfer mechanism (No handling and transfer mark to be evident during handling and transfer)- Poly-urethane coated web sling are categorically developed with a cushioning effect and reducing frictional forces between painted film and web sling.
Paint base suitability in wide range of atmospheric conditions (8 degree – 49 degree Celsius) -Solvent thinner composition derived for 3 different environmental conditions as winter, summer and rainy season with addition of high boiler like C IX and xylene, low boiler like butyl acetate.
1.First Step: Quick air-drying properties without baking oven: Thermoplastic Acrylic Resin added. Oxidative polymerization process adopted. With the help of atmospheric oxygen, unsaturated groups and hydroxyl groups are activated to link with each other to form polymeric chain. Thermoplastic acrylics added: oxidative polymerization (using atmospheric oxygen)
2.Second Step: Ketonic Resin added to get paint adhesion on Powder coated surface. Powder coating has wax on its formulation and it comes on the surface. On this surface, paint bonding is

difficult. To overcome this scenario-Ketonic Resin was added to Etch the surface (polyester and epoxy polyester powder dissolve into Ketonic solvents). On etched surface-chemical and mechanical bonding is easy and properly happened.
3.Third Step: Silicon Resin added with zirconium catalyst to form silane which stopped water molecule penetration into the paint surface.
4.Fourth Step: Dynamic composition of Thinner: India has extreme and wider range of environmental temperature (8°C to 48°C) and in this variation-paint drying and finish properties vary significantly. In winter season (8°C to 15°C)-need fast drying low boiler solvents like acetates for fast setting and drying of paint film. Similarly in summer (35-48°C) need slow boiler solvents like C-IX to avoid dry and rough setting finish of the paint film. In middle season, need a balanced between two. Hence winter, summer and regular quick drying thinner developed.
Thermoplastic acrylic and modified acrylic resin is the polymer of acrylic monomer like methyl methacrylate, butyl methacrylate, styrene etc. which has unsaturation and free hydroxyl groups which can make free radical in presence of oxygen and then make polymeric chain as cured film. Reaction takes place rapidly.
Ketonic resins on the other hand had ketonic oxygen and free hydroxyl groups to react with other unsaturated groups. It reacts with polyester film surface and etch the surface to enhance mechanical and chemical bonding with precoated surface with polyester films.
Silicon Resin in presence of zirconium and other metal cation forms silane which narrow down or close down the voids between paint polymers and metal substrates. Thus, water molecules can not enter into paint film and can not damage the paint film easily. Paint film setting and drying depends on solvent evaporation rate initially. When the solvents present in the paint evaporates fast (low boilers) the paint film stars setting and drying fast and vice versa for slow evaporating solvents (high boilers). India has extreme and wider range of environmental temperature (8°C to 48°C) and in this variation-paint drying and finish properties vary significantly. In winter season (8°C to15°C)-need fast drying low boiler solvents like acetates for fast setting and drying of paint film. Similarly in summer (35-48°C) need slow boiler solvents like C-IX to avoid dry and rough setting finish of the paint film. In middle season need a balanced between two. Hence winter, summer and regular quick drying thinner developed.

5 In another aspect of the present invention, the hard surface attained helps in increasing the
resistance of the paint film that further helps in improving water repellency properties to eliminate rainwater marks on the paint film.
In another aspect of the present invention the hard surface attained helps in increased corrosion
10 resistance with anticorrosive elements like strontium.
In another aspect of the present invention the zirconium (Zr) enhances paint adhesion and creates metal bonding. The presence of zirconium also seals the voids of paint film in combination with silicon resin.
15 Further the above composition was prepared using titanium (Ti), however it is not much effective
and proven till date.
In an embodiment of the present invention thinner is selected from xylene, butanol, butyl acetate,
cellosolve acetate and combination thereof.
In an embodiment of the present invention extender is selected from barium sulphate.
20 In an embodiment of the present invention the coating composition comprises a pigment.
In an embodiment of the present invention the method for preparing the coating composition
includes:
(i) adding thermoplastic acrylic resin for oxidative polymerization process with the help of
atmospheric oxygen, wherein unsaturated groups and hydroxyl groups are activated to link with
25 each other to form polymeric chain.
(ii) adding ketonic resin to get paint adhesion on powder coated surface.
(iii) adding resin with zirconium catalyst to form silane; wherein Zirconium is used in powder
form Zirconium Fluoride (ZrF4,H2O);
(iv) adding thinner selected from acetates, slow boiler solvents like C-IX, xylene or butanol. 30
In an embodiment of the present invention the coating composition is applied on the coating
substrate having multiple base coating selected from nano coating, powder coating, zinc plating,
2K epoxy coating, acrylate alkyd coating.
35 Examples
Paint Preparation Process:-
14

5 Step-1: Premixing of all resins, fillers, pigments and 4-5% solvents in bead mill maintaining
Temperature of 10-15 deg C, Time 30 min.
Step-2: Transfer this premix to horizontal sand mill. Add other additives and 2-3% solvents in the
premix. Two complete turn over or passes, Temperature 5-15 deg C
Step-3: Grinding or pigment dispersion, it is 7 Hegman gauge
10 Step-4: Final adjustment with 2-4% solvents for viscosity. This is 50-70 sec.
Step-5: Filtration.
Accelerated weathering test for testing the future possibilities of materials durability under certain
environmental conditions like exposure to ultraviolet lights, solar radiation, corrosive
15 environments, extreme temperature and humidity conditions was conducted.
Salt spray test also known as salt fog test was conducted for testing corrosion and corrosion resistance of the coating. The results obtained are as mentioned below:
SST & UV Test Report of New Quick Air Dry Frame Black(55300051510)
System: HRS Sheet > Shot Blasting > Nano Coating > CED Coating > New Frame Black
Date of Exposure: 05.02.2022
Date of Completion: 16.03.2022

Panel
CED coated sheet 7 mm
Size : 6 * 4
inch
(Salt Spray
Test)

DFT
CED coating DFT: 25-30 micron
Top Coat DFT: 25-30 micron

Specification
After Exposure of 1000 Hrs.
Rust creepage < 1.5 mm on either side of X line
Blister size max 8F Secondary adhesion (X cut) should pass

Observation (After 1000 Hrs.)
3-4 tiny blisters along one cross line (< 8F)
Rust creepage < 1
mm
Secondary adhesion
passes

Photo (After 1032 Hrs.)

CED coated sheet 7 mm
Size : 6 * 4
inch
(Ultra Violet
Resistance
Test)

CED coating DFT: 25-30 micron
Top Coat DFT: 25-30 micron

After Exposure of 500 Hrs.
Gloss Retention > 85% No Chalking of paint film

Gloss Retention 85-87%
(Initial Gloss 15-16
unit
Final Gloss 13-14
unit)

15

Remarks: Based on the results, it can be said that new Quick Air dry paint is passing required Corrosion
resistance test and UV resistance Test.
5
SST & UV Test Report of New Quick Air Dry Frame Black(55300051510)
System: HRS Sheet > Shot Blasting > Nano Coating > CED Coating > New Frame Black (Dev Sample)
Date of Exposure: 11.12.2021
Date of Completion: 02.01.2022 (500 Hrs)

Panel
CED coated sheet 7 mm
Size : 6 * 4
inch
(Salt Spray
Test)
CED coated sheet 7 mm
Size : 6 * 4
inch
(Ultra
Violet
Resistance
Test)

DFT
CED coating DFT: 25-30 micron
Top Coat DFT: 25-30 micron
CED coating DFT: 25-30 micron
Top Coat DFT: 25-30 micron

Specification
After Exposure of 1000 Hrs.
Rust creepage < 1.5 mm on either side of X line
Blister size max 8F Secondary adhesion (X cut )should pass
After Exposure of 500 Hrs.
Gloss Retention >
85%
No Chalking of paint
film

Observation (After 1000 Hrs.)
Full of Blisters
Rust creepage 1.4
mm
Secondary adhesion
fails
Gloss Retention 66-67%
(Initial Gloss 15-16 unit Final Gloss 6-7 unit)

Photo (After 1032 Hrs.)



Remarks: In SST-because of low water and salt resistance (excess water permeability)- salt solution penetrates the paint and react with base metal substrate to create blisters. QUV Test is also failing
16

The present disclosure provides Min 4B as per ASTM D 3359 Adhesion on Frame: Long Member (Powder coated), Cross Member (CED coated), casting brackets (casting sealer coated) and Zinc Plated brackets.
Advantages:
1. The paint has good UV resistance, water resistance and adhesion on the base paint.
2. Fast drying without baking oven-unsaturated polymers and resins like thermoplastic acrylics (8-10%) and modified acrylics (27-32%) added in the paint formulation.
3. Overcoming paint adhesion issue on powder coated surface (base coat)- ketonic resin (8-10%) added to etch the powder coated surface to enhance mechanical bonding between powder coated surface and paint film.
4. Water marks on painted surface when painted frames exposed under raining- Silicon Resin (4-5%) and zirconium metal added to form silane bonding with frame surface closing all entry voids for water.
5. No paint deformation while transferring painted frames- Thermoplastic Resins (8-10%) added in paint develops initial surface hardness and silicon resin (5- 6%) with superfast

drying of paint film. This mixture enables no inter-lateral separation of paint layers during external frictional force application. 6. Baking oven for paint film polymerization is eliminated through which propane gas and electrical energy saved resulting into global gas house (GHG) emission reduction of more than 1200 t CO2e/year.

We Claim:
1. A coating composition comprising:
an acrylated alkyd resin in an amount of 27 wt.% to 32 wt. %; a thermoplastic acrylic resin in an amount of 8 wt.% to 10 wt. %; a silicon resin in an amount of 4 wt.% to 5 wt. %; a ketonic resin in an amount of 5 wt.% to 6 wt. %; a zirconium catalyst in an amount of 0.5 wt.% to 0.6 wt.%; and thinner in an amount of 10-12%; and
fillers or extenders in an amount of: 34.4-45.5% based on total weight of the coating composition.
2. The coating composition as claimed as in claim 1, wherein the acrylic resin is a polymer of monomer units selected from methyl methacrylate (MMA) and Butyl Methacrylate (BMA) monomer for modified acrylic or acrylated alkyd resin having molecular weight of 40000-50000.
3. The coating composition as claimed as in claim 1, wherein thermoplastic acrylic resin is styrene and butyl acrylate monomers or combination thereof having molecular weight of 80000-90000.
4. The coating composition as claimed in claim 1, wherein the thermoplastic acrylic resin is selected from monomer units of methyl methacrylate, butyl acrylate or combination thereof.
5. The coating composition as claimed in claim 1, wherein the silicon resin is polymer of monomer units of methyl tri ethoxy silicone resin, octamethyl cyclo tetra siloxane or combination thereof.
6. The coating composition as claimed in claim 1, wherein the ketonic resin is prepared from cyclohexanone and aldehyde.
7. The coating composition as claimed in claim 1, wherein the coating composition comprising pigment and is selected from carbon black.

8. The coating composition as claimed in claim 1, wherein the coating composition optionally comprising dispersing agent, anti-sagging agent, anti-settling agent, antifoaming agent, dispersing agent, and UV additive selected from bentone Gel or Bentonite, aluminium stearate, Tinuvin 238.
9. The coating composition as claimed in claim 1, wherein the coating composition is an air-dry coating composition and is applied as a topcoat on a coating substrate.
10. The coating composition as claimed in claim 1 to 8, wherein the coating composition is applied on the multiple coating substrate having multiple base coating selected from nano coating and Cathodic Electro Deposition, powder coating, zinc plating, 2K epoxy coating.
11. The coating composition as claimed in claim 1 to 9, wherein the coating substrate is a chassis frame structure, hot rolled coils, castings, forgings or semi elliptical springs.
12. The coating composition as claimed in claim 1, wherein the coating composition is an air-dry coating composition and is applied as a topcoat on a substrate.
13. A method for preparing the coating composition as claimed in claim 1, comprises:
(i) adding thermoplastic acrylic resin for oxidative polymerization process with the help
of atmospheric oxygen, wherein unsaturated groups and hydroxyl groups are activated to link with each other to form polymeric chain;
(ii) adding ketonic resin to get paint adhesion on powder coated surface;
(iii) adding resin with Zirconium catalyst to form silane; wherein Zirconium is used in
Powder form Zirconium Fluoride (ZrF4,H2O);
(iv) Adding thinner selected from acetates, slow boiler solvents like C-IX, or xylene.