Coating formulation with enhanced metal adhesion

1. A coated steel structure, comprising:

a steel surface; and directly adhered to the steel surface;

a coating layer obtained by applying to the surface, a coating composition; and then curing the composition; wherein the coating composition comprises:

a resin component comprising a thermoplastic resin;

a liquid monomer component comprising a methacrylate or acrylate monomer; and

an organic peroxide initiator or an azo initiator;

wherein

the thermoplastic resin comprises as polymerized units:

at least one monofunctional monomer selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 2-ethylhexyl (meth)acrylate and

at least one acid monomer selected from the group consisting of an acid (meth)acrylate and a beta-carboxyethyl acrylate of formula:

wherein n=1-20, and/or

a polymerizable dicarboxylic acid.

2. The coated steel structure according to claim 1 , wherein the thermoplastic resin is at least one selected from the group consisting of copolymers and terpolymers of a methacrylate monomer.

3. The coated steel structure according to claim 2 , wherein the thermoplastic resin comprises a (meth)acrylate copolymer.

4. The coated steel structure according to claim 1 , wherein the thermoplastic resin comprises at least one of a copolymer or terpolymer obtained by polymerizing monomers comprising at least one monomer selected from the group consisting of methyl (meth)acrylate, ethyl (meth)-acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

5. The coated steel structure according to claim 1 , wherein the thermoplastic resin further comprises a reaction product of one or more dienes with at least one selected from the group consisting of styrene, vinyltoluene, vinyl chloride, vinyl acetate, vinylidene chloride and a vinyl ester.

6. The coated steel structure according to claim 1 , wherein the methacrylate or acrylate monomer component is at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 2-ethylhexyl (meth)acrylate.

7. A process for producing the coated steel structure, according to claim 1 , the process comprising:

applying a composition to the steel structure; and

free radical polymerization of the applied composition;

wherein the composition comprises:

a resin component comprising a thermoplastic resin;

a liquid monomer component comprising a methacrylate or acrylate monomer; and

an organic peroxide initiator or an azo initiator;

wherein

the thermoplastic resin comprises as polymerized units:

at least one monofunctional monomer selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 2-ethylhexyl (meth)acrylate and

at least one acid monomer selected from the group consisting of an acid (meth)acrylate and a beta-carboxyethyl acrylate of formula:

wherein n=1-20, and/or

a polymerizable dicarboxylic acid.

8. The process for producing the coated steel structure according to claim 7 , wherein the initiator is an organic peroxide.

9. The process for producing the coated steel structure according to claim 8 , wherein the organic peroxide is selected from the group consisting of dialkyl peroxides, keto peroxides, peroxy esters, diacyl peroxides, hydroperoxides and peroxy ketals.

10. A method to coat a metal surface, comprising:

applying a coating composition to the metal surface; and

free radically polymerizing the applied coating composition on the metal surface;

wherein the thermoplastic resin comprises as polymerized units:

at least one monofunctional monomer selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate and 2-ethylhexyl (meth)acrylate and

at least one acid monomer selected from the group consisting of an acid (meth)acrylate and a beta-carboxyethyl acrylate of formula:

wherein n=1-20, and/or

a polymerizable dicarboxylic acid.

11. The coated steel structure according to claim 1 , wherein the coating composition comprises an organic peroxide initiator, and the organic peroxide initiator is dibenzoyl peroxide, and the composition further comprises a tertiary amine.

12. The coated steel structure according to claim 11 , wherein the tertiary amine is N,N-dimethylaniline or an N,N-dialkyl-p-toluidine.

13. The coated steel structure according to claim 11 , wherein a weight % of the tertiary amine in the coating composition is from 0.1 to 4%.

14. The process according to claim 7 , wherein the coating composition comprises an organic peroxide initiator, and the organic peroxide initiator is dibenzoyl peroxide, and the composition further comprises a tertiary amine.