DESCRIPTION:
FIELD OF THE INVENTION :
This invention relates to a undercoating water- based, low VOC , eco - friendly red oxide primer composition and is
more particularly concerned with a primer composition to be effectively coated on a wide variety of rusted materials
including iron , as well as to adhere firmly to a wide variety of top coats applied to it when it is coated upon various
substrates.
BACKGROUND OF THE INVENTION :
The ongoing worldwide efforts of various agencies and institutions to reduce global warming and create an eco -
friendly environment on which depends the future of our children (we both have children aged 6years) ignited in us a
desire to reduce the use of hazardous chemicals (our professions are related to chemicals) in our daily life. We
wanted to develop a water based red oxide primer which could be applied to various types of surfaces, particularly
rusted iron. This posed a serious practical problem as water when in contact with metal forms rust. Thus a primer
based on water to be applied on metal substrates was difficult to develop .
OBJECTS OF THE INVENTION :
It is an object of the invention to provide a eco-friendly water based red oxide primer for use on the various metal
substrates.
It is another object of the invention to provide improved properties of the normal red oxide primer through a different
approach of process and raw materials for manufacture.
It is a further object of the invention to provide a rust-converting, rust-inhibiting primer which is manufactured with
water and thinned with water and which converts rust on the surface of a metal to a passive form and provides a
coating which inhibits further corrosion.
Another object that has been achieved by the invention is to provide a primer which is economically viable for
application, since no petroleum solvents (having high and fluctuating prices) are used in the manufacturing process.
This also saves the petroleum products for the future.
SUMMARY OF THE INVENTION :
These and other objects and features of the invention are obtained by a pigmented water-based red oxide primer
which is comprised of an emulsion based on plasticizer free acryiate / styrene copolymer mixed with 100% resin, an
SGO, the SGO being present in the amount of about 20 to 60% by weight of the copolymer (this is incorporated
optionally to provide sufficient / required level of Scratch hardness on application to the metal surface) and a Poly-
isoprene based polymer, the polymer being present in the amount of 40 to 70% by weight of the copolymer, about
.5 to 5% by weight a sodium salt of polyacrylic acid as surfactant, a corrosion protector composed of fumed silica with
an amount of 1 to 20% by weight, about 0.5 to 5% by weight a coalescing agent, and about 70 to 110% by weight a
pigment, all based on the weight of the total resin content of the primer. The primer is free of acidic chelating agents
such as oxalic, tannic and phosphoric acids and has a pH in the range 8 to 8.5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS :
The resin of the primer composition of the new invention is a combination of a SGO with an plasticizer free acrytate /
styrene copolymer or an aqueous dispersion of acrylic / methacrylic copolymer and a Poly-isoprene based polymer
Polyglycol ether,like,Poly propylene glycol, Di Ethylene Glycol, Methyl Ethyl Glycol are used as coalescing agents.
A freezing stabilizer such as ethylene glycol or propylene glycol is used in the primer composition for application in
cold climates.
An ionic surfactant, effective as a dispersing agent in the form of an sodium salt of polyacrylic acid together with a
non-ionic surfactant like nonyl phenol ethoxylate 9.5 Mole which is used as a wetting agent to form an oil-in-water
emulsion. As non-ionic surfactants, ethylene oxide or propylene oxide surfactants can be suitably used.
The primer composition of the invention also contains a pigment. As pigment, the most preferred are red oxide
(Fe2 O3), zinc oxide and Zinc Chrome. Barium Sulphate, hydrated Aluminium silicate, Magnasium Silicate can also be
used as fillers
The anti-foam agent used in the invention is a non silicone solution of a poly ether modified poly dimethyl siloxane.
An Alkali soluble emulsion is used as a thickener. The aquous suspension of Hydroxy ethyl cellulose or hydroxyl
methyl ethyl cellulose can be used as stabilizers.
When used on clean or rusted metal, it is a feature of my primer composition that it can be applied directly over the
rust, it merely being desirable to dust off loose pieces of the rust. Cleaning the rusted surface by chemical means
before application of the primer composition is not necessary. The primer has a rust-converting and rust-inhibiting
action, and can be applied by conventional means, such as brushing, rolling and spraying. The composition is
effective not only to inhibit further corrosion but is effective to convert adherent rust on the surface of the substrate to
a non-active or passive form which is not actively corrosive or rust-forming, as does the solvent thinnable primers
This primer composition has a pH in the range 8 to 9, and preferably a pH of 8.5. It contains no acidic chelating
agents.
It is organic-solvent resistant, the primer is oil resistant and resistant to salt water, bleaches such as sodium
hypochlorite, and the like.
Similarly, the primer composition of the invention can be said to be "universal", i.e., it can be over coated and will
adhere firmly to oil-base and water-base paints of all types, chlorinated rubber and nitrocellulose based paints. Thus,
it can be used as a barrier coating to change paint systems.
As previously mentioned, it is a feature of the primer of the invention that it is water based. As produced, it has a
water content of about 15 to 30%, preferably 20 to 25%, by weight, with a total resin content of about 20 to 50%,
preferably 25 to 40%, by weight. But it can be readily thinned by adding water to it.
When the primer composition is applied, no extensive surface preparation is needed, it has a shelf life of several
years, and it can be stored in different containers, preferably plastic .Our primer composition is of Low VOC, non-
toxic, nonflammable, and it does not stain. It dries in less than half an hour and can be over coated in One hour
under standard conditions. The coating of the primer composition has a heat resistance up to 220" F.
It can be used in the railway, auto, paper, the like industries and for general maintenance purposes.
The following specific examples will serve further to illustrate the invention and the features thereof. In the examples
all parts are by weight.

EXAMPLE 1
Four parts of hydroxy ethyl cellulose , Ninety six parts of water, and small quantities of 5 - chloro - 2 -
methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and SPCP are mixed
under high speed stirring to form a gel and left overnight to mature.
Pigments are used in the form of 80 parts of Micronized Ferric oxide (fe203) powder, 20 parts of
micronized Barium Sulphate (BaSo4) powder, 24 parts of micronized Hydrated Aluminium Silicate(AI2o3,
2sio2, h2o) powder, 60 parts of micronized Mangnesium Silicate (3mgo,4sio2, h2o) powder, 3 parts of
Sodium Benzoate, 2 parts of Zinc Oxide, 1 part of Zinc Chrome Powder (4zncro4, k2o,h2o) are mixed
with a dispersion prepared by thoroughly mixing, 1part of hydrophobic fumed silica (Si02), 16 parts of
SGO, 1 part of SPCP ,2 parts of sodium salt of polyacrylic acid, 2 parts of nonyl phenol ethoxylate 9.5
Mole, 2 parts of Di - ethylene - Glycol, 2 parts of rheology modifier, 2 part of non silicone solution of a
poly ether modified poly dimethyl siloxane, 0.4 parts of mixture of 5 - chloro - 2 - methyl isothyozoline -
3 - one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and 80 parts of water and ground in a grinding
machine to 6-7 Hegman gauge and then again 20 parts of water is added in two stages and let down of
the machine. This let down material is generally referred to as Mill Base.
At this point 8 parts of gel, 12 parts of plasticizer free acrylate/ styrene copolymer, 5 parts of Poly-
isoprene based polymer, 1 part of acid containing crosslinked alkali soluble emulsion co polymer are
mixed one after the other under slow stirring in a mixer to 1/4 parts of the Mill base to form the final
product and the pH of the entire dispersion is stabilized between 8-8.5.
EXAMPLE 2
Three parts of Carboxy Methyl cellulose, Ninety Seven parts of water, and small quantities of 5 - chloro
- 2 - methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and SPCP are mixed
under high speed stirring to form a gel and left overnight to mature.
Pigments are used in the form of 76 parts of Micronized Ferric oxide (fe203) powder, 16 parts of
micronized Barium Sulphate (BaSo4) powder, 28 parts of micronized Hydrated Aluminium Silicate(AI2o3,
2sio2, h2o) powder, 30 parts of micronized Mangnesium Silicate (3mgo,4sio2, h2o) powder, 5 parts of
Sodium Benzoate, 6 parts of Zinc Oxide, 4 part of Zinc Chrome Powder (4zncro4, k2o,h2o) are mixed
with a dispersion prepared by thoroughly mixing, 2 parts of hydrophobic fumed silica (Si02), 10 parts of
SGO, 1 part of SPCP prepared by thoroughly mixing 2 parts of sodium salt of polyacrylic acid, 1 part of
nonyl phenol ethoxylate 9.5 Mole, 1.6 parts of Di - ethylene - Glycol, 1 part of rheology modifier, 1 part
of non silicone solution of a poly ether modified poly dimethyl siloxane, 0.4 parts of mixture of 5 - chloro
- 2 - methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and 84 parts of water
and ground in a grinding machine to 6-7 Hegman gauge and then again 20 parts of water is added in two
stages and let down of the machine. This let down material is generally referred to as Mill Base.
At this point 12 parts of gel ,10 parts of an aqueous dispersion of acrylic/ methacrylic copolymer, 5 parts
of Poly-isoprene based polymer, 1 part of acid containing crosslinked alkali soluble emulsion co polymer
are mixed one after the other under slow stirring in a mixer to % parts of the Mill base to form the final
product and the pH of the entire dispersion is stabilized between 8-8.5.

EXAMPLE 3
Three parts of hydroxy ethyl cellulose / Carboxy Methyl Cellulose, Ninety seven parts of water, and small
quantities of 5 - chloro - 2 - methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 -
one(MIT) and SPCP are mixed under high speed stirring to form a gel and left overnight to mature.
Pigment in the form of 92 parts of Micronized Ferric oxide (fe203) powder, 12 parts of micronized Barium
Sulphate (BaSo4) powder, 8 parts of micronized Hydrated Aluminium Silicate(AI2o3,2sk2, h2o) powder,
8 parts of micronized Mangnesium Silicate (3mgo,4sk)2, h2o) powder, 6 parts of Sodium Benzoate, 6
parts of Zinc Oxide are mixed with a dispersion prepared by thoroughly mixing, 32 parts of SGO ,1.5part
of hydrophobic fumed silica (Si02) and 1 part of SPCP, 2 parts of sodium salt of polyacrylic acid, 2 parts
of nonyl phenol ethoxylate 9.5 Mole, 2 parts of Mono - propelene - Glycol, 1.5 parts of rheoiogy modifier,
2 part of solution of a poly ether modified poly dimethyl siloxane, 0.4 parts of mixture 5 - chloro - 2 -
methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and 76 parts of water and
ground in a grinding machine to 6-7 Hegman gauge and then again 14 parts of water is added in two
stages and let down from the machine. This let down material is generally referred to as Mill Base.
At this point 9 parts of gel, 15 parts of plasticizer free acrylate/ strene copolymer, 9.5 parts of Poly-
isoprene based polymer, 0.8 part of acid containing crosslinked alkali soluble emulsion co polymer are
mixed one after the other under slow stirring in a mixer to 1/4rts of the Mill base to form the final
product and the pH of the entire dispersion is stabilized between 8-8.5.
EXAMPLE 4
Three parts of hydroxy ethyl cellulose / Carboxy Methyl Cellulose, Ninety seven parts of water, and small
quantities of 5 - chloro - 2 - methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 -
one(MIT) and SPCP are mixed under high speed stirring to form a gel and left overnight to mature.
Pigment in the form of 112 parts of Micronized Ferric oxide (fe203) powder, 12 parts of micronized
Barium Sulphate (BaSo4) powder, 8 parts of micronized Hydrated Aluminium Silicate(AI2o3,2sio2, h2o)
powder, 8 parts of micronized Mangnesium Silicate (3mgo,4sio2, h2o) powder, 20 parts of Sodium
Benzoate, 12 parts of Zinc Oxide and 8 parts of Zinc Chrome Powder (4zncro4, k2o,h2o) are mixed with
a dispersion prepared by thoroughly by mixing, 16 parts of SGO, 20 parts of hydrophobic fumed silica
(Si02) and 1 part of SPCP, 2 parts of sodium salt of polyacrylic acid, 2 parts of nonyl phenol ethoxylate
9.5 Mole, 2 parts of Mono - propelene - Glycol, 2 parts of rheoiogy modifier, 2 part of solution of a poly
ether modified poly dimethyl siloxane, 0.4 parts of mixture 5 - chloro - 2 - methyl isothyozoline - 3 -
one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and 68 parts of water and ground in a grinding
machine to 6-7 Hegman gauge and then again 14 parts of water is added in two stages and let down
from the machine. This let down material is generally referred to as Mill Base.
At this point 10 parts of gel ,24 parts of plasticizer free acrylate/ strene copolymer, 12 parts of Poly-
isoprene based polymer ,0.4 part of acid containing crosslinked alkali soluble emulsion co polymer are
mixed one after the other under stow stirring in a mixer to V* parts of the Mill base to form the final
product and the pH of the entire dispersion is stabilized between 8-8.5.

EXAMPLE 5
Three parts of hydroxy ethyl cellulose / Carboxy Methyl Cellulose, Ninety seven parts of water, and small
quantities of 5 - chloro - 2 - methyl isothyozoline - 3 - one(CIT) & 2 - Methyl isothyozoline - 3 -
one(MIT) and SPCP are mixed under high speed stirring to form a gel and left overnight to mature.
Pigment in the form of 112 parts of Micronized Ferric oxide (fe203) powder, 12 parts of micronized
Barium Sulphate (BaSo4) powder, 8 parts of micronized Hydrated Aluminium Silicate(AI2o3,2sio2, h2o)
powder, 8 parts of micronized Mangnesium Silicate (3mgo,4sio2, h2o) powder, 18 parts of Sodium
Benzoate, 8 parts of Zinc Oxide and 16 parts of Zinc Chrome Powder (4zncro4, k2o,h2o) are mixed with
a dispersion prepared by thoroughly by mixing, 20 parts of hydrophobic fumed silica (Si02) and 1 part of
SPCP, 3 parts of sodium salt of polyacrylic acid, 2 parts of nonyl phenol ethoxylate 9.5 Mole, 2 parts of
Mono - propelene - Glycol, 2 parts of rheology modifier, 2 part of solution of a poly ether modified poly
dimethyl siloxane, 0.4 parts of mixture 5 - chloro - 2 - methyl isothyozoline - 3 - one(CIT) & 2 - Methyl
isothyozoline - 3 - one(MIT) and 72 parts of water and ground in a grinding machine to 6-7 Hegman
gauge and then again 16 parts of water is added in two stages and let down from the machine. This let
down material is generally referred to as Mill Base.
At this point 8 parts of gel, 25 parts of, plasticizer free acrylate/ strene copolymer, 15 parts of Poly-
isoprene based polymer ,0.5 part of acid containing crosslinked alkali soluble emulsion co polymer are
mixed one after the other under slow stirring in a mixer to 1/4 ts of the Mill base to form the final
product and the pH of the entire dispersion is stabilized between 8-8.5.
Example 6
Rusted 150mm X 150mmX1.25mm mild steel panels were coated on both sides with the primer
composition produced in example 5 by either brushing or spraying to give a dry film. Allow it to air dry for
72 hrs and then place it in a corrosion cabinet maintained at 100% relative humidity and a temperature
cycle of 42* to 48*C for 7 days and examining it for any signs of deterioration and corrosion of metal
surface. This is done by removing 25mm strip of the film from the centre of the panel carefully with a
suitable paint remover and examine the exposed metal for signs of corrosion neglecting 25mm portion of
exposed surface from each end. The whole testing is done under paragraph 18 of IS: 101-1964.
Suitable Paint Remover:
Cellulose Acetate — 43.00
Paraphffin 7.00
Methylene Chloride — 38.00
Methylated Spirit 8.00
TRO 4.00

Example 7
Resistance to Solvent
Clean 150mm X150mmX1.25mm mild steel panels were coated on both sides with the primer
composition produced in example 3 by either brushing or spraying to give a dry film. Allow it to air dry
for 72hrs and then place it in mineral spirit, high aromatic hydrocarbon solvent like xylene and toluene
separately for 30 days. When the panels were removed from the different solvents and dried and
examined, the coat was still completely intact and had not lifted in any way.
Example 8
Resistance to Salt
Clean 150mm X 150mmX1.25mm mild steel panels and aluminium foil were coated on both sides with
the primer composition produced in example 4 by either brushing or spraying to give a dry film. Allow it to
air dry for 72hrs and the immersed in a 10% aqueous solution of sodium chloride for 240Hrs.
Upon removal of the mild steel panels / aluminium foil from the sodium chloride solution and re-
examination, the coating was seen to be wholly intact in all cases.
Example 9
Resistance to heat
Apply a coat of the material produced in example 3 by either brushing or spraying to a 150X100X1.25mm
mild steel plate to give a dry film. Allow the panel to air dry in a horizontal position for 72 hrs. Heat the
panel gradually to the temperature upto 200*F and maintain there for 2 hours. Keep it at room
temperature for 1 hour and then examine the film. The film will remain firmly adherent and shall not show
signs of cracking , blistering or change of colour. This test is done as per paragraph 22 of IS: 101-1964.
Example 10
Compatibility to top Coat
Rusted 150mm X 150mmX1.25mm mild steel panels are coated on both sides with the primer
composition produced in example 3 by either brushing or spraying to give a dry film. Allow it to air dry for
72hrs and top coated with a top coat of enamel paint based on alkyd resin, epoxy based top coat or a
nitrocellulose based top coat The paint film is bent thru 180* after complete drying of the top coat, 75mm
from the upper edge over a 6.25mm diameter rod with the paint film outside. The time of bending shall not
exceed 1 second. The paint film will not show damage, detachment or cracking examined under X10
magnification. This test is done as per paragraph 16 of IS: 101 -1964.

Example 11
Hardness test
Clean 150mm X 150mmX1.25mm mild steel panels are coated on both sides with the primer composition
produced in example 3 by either brushing or spraying to give a dry film. Allow it to air dry for 72hrs and
test the panel under a load of 1000gms. Fix the hard steel needle (which is hemispherical and 1mm in
diameter) at the end of the counterpoise, which is kept horizontal by adjusting the length of the needle
and draw the panel under the needle at a rate of 30 to 40 mm per second. A scratch, showing the bare
metal shall not be produced when tested. This test is done as per paragraph 15 of IS : 101-1964.
Example 12
Pressure test
Apply a coat of the material produced in example 4 on a tinned panel of .315mm to give a dry film. Allow it
to air dry in a horizontal position. At the end of the period cut 2 pieces approximately of 20mm each.
Superimpose them so that the paint films are in close contact, and place on the metal table. Lower the
steel ball and plunger to the center of the metal test pieces and place a 1.81 Kg weight on top of the
plunger. Maintain the pressure on the paint film for 5 minutes. At the end of this period, separate and
examine the test pieces. The metal surface shall not be rendered visible when two pieces are separated
after the test is carried out as prescribed in pare 15.2.2 of IS: 101-1964.
NB : As per IS : 101 Oil Based primers need to be air dried for 24 hrs after paneling before any
tests can be conducted on them. But as this is a water Based primer we recommend that the
coated panels be allowed to air dry for 72Hrs before conducting of any tests as per IS : 101.

I Claim :
1. A water based anti corrosive paint primer which is effectively adherent to rusted metal and other substrates and to
a variety of top coats, comprising : an aqueous emulsion or aqueous suspension of plasticizer free acrylate / styrene
copolymer, the aqueous emulsion or aqueous suspension having a pH of about 8, a solid grade oligomer (SGO)
(this is incorporated optionally to provide sufficient / required level of Scratch hardness on application to the metal
substrate) and Poly-isoprene based polymer, a corrosion protector composed of fumed silica, a rust inhibitor formed
from a combination of Sodium Benzoate & Zinc Oxide(ZnO) and /or Zinc Chrome Powder (4zncro4, k2o,h2o).
and having a triethanolamine salt as lnic surfactant, non silicone defoamer (solution of a poly ether modified poly
dimethyl siloxane), a coalescing agent and a pigment.
2. A primer as defined in claim 1; wherein the corrosion protector is a hydrophobic fumed silica (SiO2)roviding
effective rheology control after being treated with HMDS as an anti settling agent for the stabilization of pigments & to
enhance the effect of corrosion protection present in the amount of about 0.25 to 7% preferably 1 to 5% by weight
of the primer.
3. A primer as defined in claim 1; further the corrosion protector a hydrophobic fumed silica (SiO2) providing
effective rheology control after being treated with HMDS as an anti settling agent for the stabilization of pigments & to
enhance the effect of corrosion protection is present in the amount of about 1 to 20% preferably 2 to 12% all based
on the weight of the total resin content of the primer.
4. A primer as defined in claim 1; wherein the Solid grade oligomer (SGO) having a mid range molecular weight
and soluble in alkaline water is present in the amount of about 2 to15% preferably 4 to 10% by weight of the primer
(This is incorporated optionally to provide sufficient / required level of Scratch hardness on application to the metal
surface).
5. A primer as defined in claim 1; further the Solid grade oligomer (SGO) having a mid range molecular weight and
soluble in alkaline water is present in the amount of about 20 to 60% preferably 25 to 45% all based on the weight of
the total resin content of the primer.
6. A primer as defined in claim 1; Wherein the Poly-isoprene based polymer is present in the amount of 5 to 20%
preferably 8 to 15% by weight of the primer.
7. A primer as defined in claim 1; further the Poly-isoprene based polymer is present in the amount of 40 to 70%
preferably 45 to 65% all based on the weight of the total resin content of the primer.
8. A primer as defined in claim 1; wherein the rust inhibitor is a combination of Sodium Benzoate &
Zinc Oxide(ZnO) and /or Zinc Chrome Powder (4zncro4, k2o,h2o).
9. A primer as defined in claim 1; further the rust inhibitor is a combination of Sodium Benzoate & Zinc
Oxide(ZnO) and /or Zinc Chrome Powder (4zncro4, k2o,h2o) and Sodium Benzoate is present in the amount
of 0.5 to 6% preferably 1 to 4% by the weight of the primer.
10. A primer as defined in claim 1; further the rust inhibitor is a combination of Sodium Benzoate & Zinc
Oxide(ZnO) and /or Zinc Chrome Powder (4zncro4, k2o,h2o) and Zinc Oxide(ZnO) and / or Zinc Chrome
Powder (4zncro4, k2o,h2o) is present in the amount of 1 to 7% preferably 1.5 to 6% by the weight of the
primer.

11. A primer as defined in claim 1; wherein the plasticizer free acrylate / styrene copolymer is a pure acrylate or a
styrene copolymer having a styrene content of 45 to 55% and is present in the amount of 10 to 30% preferably 15 to
25% by weight of the primer.
12. A primer as defined in claim 1; wherein the pigment includes Ferric oxide (Fe2 O3) and is present in the amount
of 15 to 40% preferably 20 to 30% by weight of the primer.
13. A primer as defined in claim 1; further Ferric oxide (Fe2 O3) is present in the amount of 70 to 110% preferably
80 to 100% all based on the weight of the total resin content of the primer
14. A primer as defined in claim 1; further including a non-ionic surfactant.
15. A primer as defined in claim 1; wherein the biocide is a mixture of 5 - chloro - 2 - methyl isothyozoline - 3
- one(CIT) & 2 - Methyl isothyozoline - 3 - one(MIT) and incan preservative is a mixture of diuron, carbendazim
& OIT.
16. A primer as defined in claim 1; wherein the coalescing agent is a polyglycol
17. A primer as defined in claim 1; wherein the freezing stabilizer is propylene glycol
18 A primer as defined in claim 1; wherein the primer has a pH in the range 7-9 specifically of 8.5 ..
19. A primer as defined in claim 1; further including a alkali soluble emulsion acting as thickener.
20. A primer as defined in claim 1; wherein the coalescing agent is Di Ethylene Glycol (DEG).
21. A primer as defined in claim 1; wherein the primer is free of oxalic acid, tannic acid and phosphoric acid.
22. A primer as defined In claim 1; wherein the primer is free of acidic chelating agents.

A water based primer effectively adherent to rusted metal and other substrates and to a variety of top coats has the
form of an aqueous emulsion or aqueous suspension of an plasticizer free acrylate / styrene copolymer or an
aqueous dispersion of acrylic/ methacrylic copolymer, Poly-isoprene based polymer, the Poly-isoprene based
polymer being present in the amount of 40 to 70 % by weight of the copolymer, and a solid grade oligomer, the
oligomer being present in the amount of about 20 to 60% by weight of the copolymer (this is incorporated optionally
to provide sufficient / required level of Scratch hardness on application to the metal substrate), about .5 to 5% by
weight a sodium salt of polyacrylic acid as surfactant, a corrosion protector composed of fumed silica with an
amount of 1 to 20% by weight, about 0.5 to 5% by weight a coalescing agent, and about 70 to 110% by weight a
pigment, all based on the weight of the total resin content of the primer.