Description:TECHNICAL FIELD
The present disclosure relates to a polymer composition for surface treatment of materials. More particularly, the present disclosure relates to a multifunctional polymer coating composition suitable for coating various surfaces such as glass, metal, ceramics, etc.

BACKGROUND
Bottles, containers, jars, etc., used particularly in the cosmetic, liquor, perfume, home décor and household goods industry are often made aesthetically appealing by adding a coating/decoration to the surface. The presentation of these containers plays a vital role in attracting consumers to the product, and has been proven effective at increasing sale of the product. Thus, in these industries, the manufacturers give the best possible aesthetics and packaging to their products by way of original shapes, coatings and decorations, to attract the consumers.

In the past several polymer compositions have been developed for surface coatings. Some drawbacks of the traditional compositions include presence of impurity which can hamper the coating quality, incompatibility with alcohol, chemicals, etc., low clarity, low gloss, low adhesion and low printability. Furthermore, combining multiple functional additives can lead to phase separation, aggregation or poor dispersion, and the coatings designed to perform multiple roles may suffer from poor adhesion to the substrate or incompatibility with underlying layers.

There is therefore need for a multifunctional polymer composition for surface coating of materials such as glass, metal, ceramics, and the like, which will overcome the afore-said drawbacks to provide a composition which can provide one or more advantages including clarity, superior quality, chemical resistance, corrosion resistance, compatibility with substrate materials, alcohol, perfume, cosmetics, etc., high gloss, good adhesion, scratch resistance, good printability, suitable for hot stamp foiling, and the like.

OBJECTS
Accordingly, an object of the present disclosure is to overcome the afore-noted deficiencies of the prior art, and provide a multifunctional polymer coating composition for coating various surfaces including, but not limited to, glass, metal, ceramics, and the like.

According to another object of the present disclosure the multifunctional polymer coating composition is crystal clear in appearance, provides a superior quality coating with exceptional chemical resistance, corrosion resistance, and compatibility with alcohol, perfume, cosmetics, etc., high gloss, excellent adhesion, high scratch resistance, good printability and suitability for hot stamp foiling.

These and other features, aspects and advantages of the present disclosure will become better understood with regard to the following description and examples.

SUMMARY
The present disclosure describes a multifunctional polymer coating composition. The composition comprises 5 to 35 % (w/w) at least one resin, 1 to 25 % (w/w) at least one amino crosslinker, 0.1 to 7 % (w/w) at least one catalyst, 5 to 20 % (w/w) at least one block hardener, and at least one solvent.

According to a preferred embodiment, the multifunctional polymer coating composition comprises at least one resin selected from the group consisting of polyester polyol, thermosetting acrylic resin, saturated carboxylated polyester resin, fatty acid based polyester resin, epoxy resin, and combinations thereof. Preferably, the resin has a hydroxyl value in the range of 50 - 200 KOH/mg and a functionality in the range of 2 – 4.

Preferably, the amino crosslinker is an amino resin selected from the group consisting of melamine formaldehyde, urea formladehyde, highly methylated melamine resin (HMMM), melamine formaldehyde in methanol, melamine formaldehyde in butanol, and the like.

Preferably, the catalyst is selected from an acid catalyst, more preferably, a para-toluene sulfonic acid catalyst or naphthalene sulfonic acid catalyst. Preferably, the block hardener is selected from the group consisting of isophorone diisocyanate based, hexamethylene diisocyanate based, and toluene diisocyanate (TDI) based compounds.

According to a preferred embodiment, the multifunctional polymer coating composition comprises one or more ingredients selected from the group consisting of saturated carboxylated polyester resin, acid anhydride, short oil alkyd resin, high functional polyester polyol, acrylic, thermosetting acrylic resin, epoxy resin, hydrocarbon resin, flow additives, surface modifiers, wetting additives, levelling additives, stability additives, dyes, adhesion promoters, dispersing additives, viscosity reducer, and the like.

Preferably, the saturated carboxylated polyester resin has an acid value in the range of 30 to 105 KOH/mg and a functionality in the range of 2 – 5. The coating composition may comprise an acid anhydride selected from the group consisting of hexahydrophthalic anhydride (HHPA), maleic anhydride, trimellitic anhydride (TMA), and the like. The coating composition may comprise a short oil alkyd resin selected from a group consisting of coconut oil fatty acid-based resin, dehydrated castor oil (DCO) fatty acid-based resin, soybean oil fatty acid (SOFA)-based alkyd resin, and the like.

The multifunctional polymer coating composition may comprise a high functional polyester polyol having a high hydroxyl value in the range of 300-400 KOH/mg and high functionality. The multifunctional polymer coating composition may comprise thermosetting acrylic resin selected from a group consisting of hydroxyl-terminated acrylic resins, -COOH terminated acrylic resins, and the like. The multifunctional polymer coating composition may comprise hydrocarbon resin selected from a C9/C10 aromatic hydrocarbon resin. The multifunctional polymer coating composition may comprise epoxy resin having an epoxy equivalent weight (EEW) in the range of 200-1000.

Preferably, the multifunctional polymer coating composition comprises flow additives, stability additives, and/or surface modifiers including wetting additives and/or levelling additives. The flow additives may be selected from high molecular weight acrylic arylate based additives. The stability additives may be selected from a group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), triphenyl phosphite (TPP), monomethyl ether of hydroquinone (MEHQ), hydroquinone, hindered amine light stabilizers (HALS), and other light stabilizers. The surface modifiers, wetting additives and levelling additives are selected from silicone-based additives.

Preferably, the multifunctional polymer coating composition comprises a silane compound adhesion promoter.

Preferably, the solvent is selected from a group consisting of toluene, o-xylene, methyl ethyl ketone, butyl acetate, ethyl acetate, cyclohexanone, cyclohexanol, dimethyl formide, isopropyl alcohol, tetrahydrofuran, methyl isobutyl ketone, dimethyl sulfoxide, n-butanol, butyl alcohol, 2-ethoxyethanol (ethyl cellosolve), diacetone alcohol, alkyl benzene, 2-ethoxyethyl acetate (cellosolve acetate), propylene glycol methyl ether, propylene glycol methyl ether acetate, perchloroethylene, and the like.

DETAILED DESCRIPTION
The present disclosure describes a multifunctional polymer coating composition. Several features of the composition in accordance with exemplary embodiments are set-forth and described in the examples. The description herein after, of the specific embodiments reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that these examples are for illustrating the principles, and that the disclosure is not so limited. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not for limitation. Unless the context requires otherwise, throughout the specification and claims which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.”

A preferred embodiment of the present disclosure relates to a multifunctional polymer coating composition for coating various surfaces including, but not limited to, glass, metal, ceramics, and the like. The innovative polymer composition is developed to provide a crystal-clear coating on the substrates. The composition provides several technical advantages, including, but not limited to, superior quality coating, coating having exceptional chemical resistance, corrosion resistance, compatibility with substrate, alcohol, perfume, cosmetics, etc., high gloss, excellent adhesion, and high scratch resistance. The composition further provides good printability and is suitable for hot stamp foiling. The composition can be mixed with a dye solution to obtain a desired color to the coating. The coating composition is versatile and can be applied to a wide range of surfaces and objects to enhance their properties, add new functionalities or for aesthetic purpose. The coating composition can be applied on containers, jars and bottles used for storing cosmetics, perfumes, juices/beverages, liquor and alcohol, and other surfaces such as home décor items, household items, etc.

According to one embodiment, the multifunctional polymer coating composition comprises at least one polyester polyol resin, at least one amino crosslinker, at least one catalyst and at least one block hardener. According to a preferred embodiment, the multifunctional polymer coating composition comprises 5 to 35 % (w/w) at least one resin, 1 to 25 % (w/w) at least one amino crosslinker, 0.1 to 7 % (w/w) at least one catalyst, 5 to 20 % (w/w) at least one block hardener, and at least one solvent.

The multifunctional polymer coating composition comprises at least one resin selected from the group consisting of polyester polyol, thermosetting acrylic resin, saturated carboxylated polyester resin, fatty acid based polyester resin, epoxy resin, and combinations thereof. The resin preferably has a hydroxyl value in the range of 50 - 200 KOH/mg and a functionality in the range of 2 – 4.

The amino crosslinker is an amino resin selected from the group consisting of melamine formaldehyde, urea formladehyde, highly methylated melamine resin (HMMM), melamine formaldehyde in methanol, melamine formaldehyde in butanol, and the like. The catalyst is selected from an acid catalyst, preferably a para-toluene sulfonic acid catalyst or naphthalene sulfonic acid catalyst. The catalyst can be selected from the group consisting of CYCAT® 4045, NACURE® PC 100, NACURE® 2500, NACURE® 1051, NACURE 1051, NACURE 1323, NACURE 2107, NACURE 3525 which also helps in curing and adhesion.

The block hardener is selected from the group consisting of isophorone diisocyanate (IPDI) based, hexamethylene diisocyanate (HDI) based, and toluene diisocyanate (TDI) based compounds. Preferably, the block hardener is Desmodur® BL 3175.

The composition further comprises one or more ingredients selected from the group consisting of saturated carboxylated polyester resin, acid anhydride, short oil alkyd resin, high functional polyester polyol, acrylic, thermosetting acrylic resin, epoxy resin, hydrocarbon resin, flow additives, surface modifiers, wetting additives, levelling additives, stability additives, dyes, adhesion promoters, dispersing additives, viscosity reducer, and the like. The composition may additionally comprise one or more additives for stabilizing viscosity, removing cloudiness, promoting adhesion, and improving dispersion. The composition may additionally comprise one or more solvents or viscosity reducers.

According to one embodiment, the saturated carboxylated polyester resin is selected from a compound comprising a -COOH group at the end of the chain. Preferably, the saturated carboxylated polyester resin has an acid value from 30 to 105 KOH/mg with a functionality in the range of 2-5 which helps in rapid crosslinking. More preferably, the saturated carboxylated polyester resin can be selected from the group consisting of REAFREE® 8180, REAFREE® 8188, REAFREE® 6803-T, CRYLCOAT® 1783-0, CRYLCOAT® 1540-0, CRYLCOAT® 1703-1, REAFREE® 8400, REAFREE® 8784, REAFREE® 4002-s, CRYLCOAT® 1573, CRYLCOAT® 1510, REAFREE® 8784, and the like.

According to another embodiment, the acid anhydride can be used as a hardener for the resin. Preferably, the acid anhydride can be selected from the group consisting of hexahydrophthalic anhydride (HHPA), maleic anhydride, trimellitic anhydride (TMA), and the like.

According to one embodiment, the short oil alkyd resin can be selected from the group consisting of coconut oil fatty acid-based resin, dehydrated castor oil (DCO) fatty acid-based resin, soybean oil fatty acid (SOFA)-based alkyd resin, and the like. The high functional polyester polyol can be selected from a polyol having a branched chain, greater functionalities and high hydroxyl number in the range of 300-400 KOH/mg. Preferably, high functional polyester polyol is selected from the group consisting of SETAL® RD 181, IDESTER-1002, and the like.

The thermosetting acrylic resin can be used to crosslink with amino resin. Preferably, the thermosetting acrylic resin can be selected from the group consisting of hydroxyl-terminated acrylic resins, -COOH terminated acrylic resins, and the like. The hydrocarbon resin can be selected from a C9/C10 aromatic hydrocarbon resin.

According to one embodiment, flow additives including high molecular weight acrylic arylate based additives can be used. Preferably, the flow additives can be selected from MODAFLOW® 9200, MODAFLOW® 2100, and the like. Additionally, surface modifiers including wetting additives and/or levelling additives can be used. Preferably, the surface modifiers are silicone-based additives. The silicone-based additives can be selected from a group consisting of BYK-333, BYK-377, TEGO® Glide series, BYK-361N, CoatOSil™ 1211C, and the like.

According to one embodiment, epoxy resins having epoxy equivalent weight (EEW) in the range of 200-1000 can be used. Preferably, the epoxy resin can be selected from a group consisting of LAPOX® ARB-22, LAPOX® ARB-26, LAPOX® ARC-44, LAPOX® ARP-12, LAPOX® ARP-13HT, LAPOX® P62, LAPOX® B11, YD-115CA, YD-128s, YD-011S, YD-017, YD-903, YD-013K, YD-972, and the like.

Additionally, additives which help in retaining the in-can viscosity and maintaining clarity of the formulation for more than 220 days can be used. These additives can include antioxidants selected from a group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), triphenyl phosphite (TPP), monomethyl ether of hydroquinone (MEHQ), hydroquinone, hindered amine light stabilizers (HALS), and other light stabilizers.

According to one embodiment, the composition may comprise silanes to increase adhesion on glass substrate. Preferably, the composition may comprise a silane selected from a group consisting of Dynasylan® GLYMO, Dynasylan® AMMO, Dynasylan® VTMO, Dynasylan® MTMO, and the like. Additionally, the composition may comprise a dispersing additive selected from a group consisting of DISPERBYK®-163, TEGO® Dispers 670, TEGO® Dispers 671, TEGO® Dispers 673, and the like.

According to one embodiment, the composition may be diluted/thinned using a solvent. Preferably, the solvent can be selected from a group consisting of toluene, o-xylene, methyl ethyl ketone, butyl acetate, ethyl acetate, cyclohexanone, cyclohexanol, dimethyl formide, isopropyl alcohol, tetrahydrofuran, methyl isobutyl ketone, dimethyl sulfoxide, n-butanol, butyl alcohol, 2-ethoxyethanol (ethyl cellosolve), diacetone alcohol, alkyl benzene, 2-ethoxyethyl acetate (cellosolve acetate), propylene glycol methyl ether (DOWANOL™ PM), propylene glycol methyl ether acetate (DOWANOL™ PMA), perchloroethylene, and the like.

According to one embodiment, the multifunctional polymer coating composition can be used for coating substrate surfaces to obtain a coat having dry film thickness (DFT) of 10 to 25 microns. Preferably, as the coating thermosets, it is cured with heating at a surface curing temperature in the range of 150 to 220 °C for a duration of 3 to 15 minutes. The surface curing temperature is the substrate surface temperature.

According to one embodiment, the composition can be a clear lacquer in a sprayable form which can be sprayed on the container either manually or by using a coating system selected from semi-automatic, automatic, electrostatic, and the like. The composition can be mixed with a dye solution to obtain any desired color.

According to one embodiment, the coating so obtained has a high scratch resistance, high gloss level (above 90 when measured using a gloss meter), 50-500 rubs pass in MEK rub test (solvent rub resistance tester), 12 to 72 hours stability in alcohol dip test (resistance of coating to alcohol), and 90-100% pass in cross-cut test (resistance of coating to separation from substrates).

WORKING EXAMPLES
The present disclosure will now be described with the help of limited embodiments and/or examples, such embodiments and/or examples must not, in any manner, be construed to limit the ambit and scope of the disclosure.

Example 1: Composition 1 according to the present disclosure includes multiple resins which were reacted with an amino resin to provide high crosslinking and good chemical resistance. The composition was prepared by mixing the resins with solvent, and then adding the crosslinkers and additives to the resin mixture, mixing the resultant formulation for 1-2 hours to obtain a homogenous composition having viscosity in the range of 20 to 23 seconds in Ford cup D4 at 25 °C.

Table 1: Composition 1 according to the present disclosure
Composition 1 Quantity (wt.)
Polyester polyol 10 g
CRYLCOAT® 1540-0 24 g
LAPOX® ARB-22 14 g
Highly methylated melamine resin (HMMM) 20 g
Urea-formaldehyde resin 10 g
BYK-333 400 mg
Tego® Glide 410 400 mg
Dynasylan® GLYMO 3 g
Desmodur® BL 3175 5
CYCAT® 4045 3 g
DOWANOL™ PM 94 g

Example 2: Composition 2 according to the present disclosure includes polyester polyol and sulfonyl chloride polystyrene resin (SCPR) terminated -COOH which were reacted with an amino resin to provide high crosslinking and good chemical resistance.
Table 2: Composition 2 according to the present disclosure
Composition 2 Quantity (wt.)
Polyester polyol 12 g
CRYLCOAT® 1703-1 25 g
Highly methylated melamine resin (HMMM) 10 g
Urea-formaldehyde resin 20 g
BYK-377 200 mg
BYK-361N 200 mg
DXB-3465 7
BHT 1 g
Dynasylan® VTMO 3 g
NACURE® PC 100 3 g
Methyl ethyl ketone 75 g

Example 3: Composition 3 according to the present disclosure includes acrylic polyol having hydroxyl value between 40 to 100 and high Tg (glass transition temperature) between 40 to 75 °C which were reacted with an amino resin to provide high crosslinking and good chemical resistance. In the said example, the acrylic polyol used has a hydroxyl value of 55 and high Tg of 50 °C.
Table 3: Composition 3 according to the present disclosure
Composition 3 Quantity (wt.)
Acrylic polyol 27 g
Highly methylated melamine resin (HMMM) 15 g
Urea-formaldehyde resin 5 g
CoatOSil™ 1211C 200 mg
TEGO® Glide 450 200 mg
Desmodur® BL 3175 5
Dynasylan® AMMO 4 g
NACURE® 2500 3 g
DOWANOL™ PMA 83 g

Example 4: Composition 4 according to the present disclosure includes acrylic resin which is terminated with -COOH group having acid value between 40 to 65 and high Tg (glass transition temperature) between 40 to 75 °C which were reacted with an amino resin to provide high crosslinking and good chemical resistance. In the said example, the acrylic resin used has an acid value of 60 and very high Tg of 55 °C.
Table 4: Composition 4 according to the present disclosure
Composition 4 Quantity (wt.)
Acrylic resin 30 g
Highly methylated melamine resin (HMMM) 8 g
BYK-333 200 mg
TEGO® Glide 496 200 mg
WD-6200 10
Dynasylan® MTMO 2.5 g
NACURE® 1051 3 g
Toluene 83 g
Example 5: Composition 5 according to the present disclosure includes polyester polyol having hydroxyl value of 65, maleic anhydride and liquid epoxy resin (epoxy resin having EEW between 205 to 900) which were reacted with an amino resin to provide high crosslinking and good chemical resistance.

Table 5: Composition 5 according to the present disclosure
Composition 5 Quantity (wt.)
Polyester polyol 16 g
Maleic anhydride 5 g
Highly methylated melamine resin (HMMM) 13 g
Epoxy resin 10 g
BYK-377 200 mg
BYK-361N 200 mg
DXB-3465 10
Dynasylan® VTMO 3.5 g
NACURE® 2500 3 g
Butyl alcohol 75 g

Example 6: Composition 6 according to the present disclosure includes polyester polyol having high hydroxyl value of 150 and high functionality of 5, and coconut oil-based resin which were reacted with an amino resin to provide high crosslinking and good chemical resistance.
Table 6: Composition 6 according to the present disclosure
Composition 6 Quantity (wt.)
Polyester polyol 15 g
Coconut oil-based resin 20 g
HMMM resin 15 g
Urea-formaldehyde resin 10 g
CoatOSil™ 1211C 200 mg
TEGO® Glide 450 200 mg
Desmodur® BL 3175 5
Dynasylan® AMMO 3 g
CYCAT® 4045 3 g
Tetrahydrofuran 75 g

The compositions 1 to 6 were found to have good adhesion, alcohol resistance, chemical resistance and solvent resistance. The compositions 1 & 5 were found to be slightly hazy. Overall, the compositions 2, 4 & 6 were found to have high clarity, superior quality, high gloss, very good adhesion, good alcohol resistance, good chemical resistance and good solvent resistance.

TECHNICAL ADVANCEMENTS
The technical advancements of the present disclosure including, but not limited to,
• a multifunctional polymer coating composition for coating various surfaces including, but not limited to, glass, metal, ceramics, and the like, which has high clarity, and provides a superior quality coating with exceptional chemical resistance, corrosion resistance, solvent resistance, and compatibility with alcohol, perfume, cosmetics, etc.,
• a multifunctional polymer coating composition which provides high gloss, excellent adhesion, high scratch resistance, good printability and suitability for hot stamp foiling; and
• a multifunctional polymer coating composition which can be mixed with a dye solution to obtain any desired color.
, Claims:WE CLAIM:

1. A multifunctional polymer coating composition comprising:
5 to 35 % (w/w) at least one resin;
1 to 25 % (w/w) at least one amino crosslinker;
0.1 to 7 % (w/w) at least one catalyst;
5 to 20 % (w/w) at least one block hardener; and
at least one solvent.

2. The multifunctional polymer coating composition as claimed in claim 1, wherein the at least one resin can be selected from the group consisting of polyester polyol, thermosetting acrylic resin, saturated carboxylated polyester resin, fatty acid based polyester resin, epoxy resin, and combinations thereof.

3. The multifunctional polymer coating composition as claimed in claim 2, wherein the at least one resin has a hydroxyl value in the range of 50 - 200 KOH/mg and a functionality in the range of 2 – 4.

4. The multifunctional polymer coating composition as claimed in claim 1, wherein said composition comprises one or more ingredients selected from the group consisting of saturated carboxylated polyester resin, acid anhydride, short oil alkyd resin, high functional polyester polyol, acrylic, thermosetting acrylic resin, epoxy resin, hydrocarbon resin, flow additives, surface modifiers, wetting additives, levelling additives, stability additives, dyes, adhesion promoters, dispersing additives, viscosity reducer, and the like.

5. The multifunctional polymer coating composition as claimed in claim 1, wherein the at least one amino crosslinker is an amino resin selected from the group consisting of melamine formaldehyde, urea formladehyde, highly methylated melamine resin (HMMM), melamine formaldehyde in methanol, melamine formaldehyde in butanol, and the like.

6. The multifunctional polymer coating composition as claimed in claim 1, wherein the at least one catalyst is selected from an acid catalyst, preferably a para-toluene sulfonic acid catalyst or naphthalene sulfonic acid catalyst.

7. The multifunctional polymer coating composition as claimed in claim 1, wherein the at least one block hardener is selected from the group consisting of isophorone diisocyanate based, hexamethylene diisocyanate based, and toluene diisocyanate (TDI) based compounds.

8. The multifunctional polymer coating composition as claimed in claims 2 & 4, wherein the saturated carboxylated polyester resin has an acid value in the range of 30 to 105 KOH/mg and a functionality in the range of 2 – 5.

9. The multifunctional polymer coating composition as claimed in claim 4, wherein the acid anhydride is selected from the group consisting of hexahydrophthalic anhydride (HHPA), maleic anhydride, trimellitic anhydride (TMA), and the like.

10. The multifunctional polymer coating composition as claimed in claim 4, wherein the short oil alkyd resin is selected from a group consisting of coconut oil fatty acid-based resin, dehydrated castor oil (DCO) fatty acid-based resin, soybean oil fatty acid (SOFA)-based alkyd resin, and the like.

11. The multifunctional polymer coating composition as claimed in claim 4, wherein the high functional polyester polyol has a high hydroxyl value in the range of 300-400 KOH/mg and high functionality.

12. The multifunctional polymer coating composition as claimed in claims 2 & 4, wherein the thermosetting acrylic resin is selected from a group consisting of hydroxyl-terminated acrylic resins, -COOH terminated acrylic resins, and the like.

13. The multifunctional polymer coating composition as claimed in claim 4, wherein the hydrocarbon resin is selected from a C9/C10 aromatic hydrocarbon resin.

14. The multifunctional polymer coating composition as claimed in claim 4, wherein the flow additive is selected from a high molecular weight acrylic arylate based additive.

15. The multifunctional polymer coating composition as claimed in claims 2 & 4, wherein the epoxy resin has an epoxy equivalent weight (EEW) in the range of 200-1000.

16. The multifunctional polymer coating composition as claimed in claim 4, wherein the surface modifiers, wetting additives and levelling additives are selected from silicone-based additives.

17. The multifunctional polymer coating composition as claimed in claim 4, wherein the stability additives are selected from a group consisting of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), triphenyl phosphite (TPP), monomethyl ether of hydroquinone (MEHQ), hydroquinone, hindered amine light stabilizers (HALS), and other light stabilizers.

18. The multifunctional polymer coating composition as claimed in claim 4, wherein the adhesion promoter is a silane compound.

19. The multifunctional polymer coating composition as claimed in claim 1, wherein the solvent is selected from a group consisting of toluene, o-xylene, methyl ethyl ketone, butyl acetate, ethyl acetate, cyclohexanone, cyclohexanol, dimethyl formide, isopropyl alcohol, tetrahydrofuran, methyl isobutyl ketone, dimethyl sulfoxide, n-butanol, butyl alcohol, 2-ethoxyethanol (ethyl cellosolve), diacetone alcohol, alkyl benzene, 2-ethoxyethyl acetate (cellosolve acetate), propylene glycol methyl ether, propylene glycol methyl ether acetate, perchloroethylene, and the like.