Surface treatment method for a substrate using denatured urushiol derived from
A method of treating a surface of a substrate using modified urushiol derived from Toxicodendron vernicifluum is provided. More particularly, the reactivity of a hydroxyl group of urushiol extracted from fresh Toxicodendron vernicifluum is removed before the lacquer is used as a UV coating agent for a substrate such as a steel sheet. Therefore, the substrate may have high antibacterial activity, and excellent appearance and functionalities such as far-infrared radiation, blocking of electromagnetic waves, enhanced corrosion resistance, high crosslinking speed when a low content of a photoinitiator is used, excellent surface gloss and high scratch resistance.
1. A composition for coating surface of steel sheet, comprising:
a binder comprising an oligomer and an acrylate monomer, in which the oligomer includes a urethane-based modified epoxy acrylate and a urethane acrylate, and the acrylate monomer includes a monofunctional acrylate monomer and a trifunctional acrylate monomer; and
a compound represented by Formula 1:
wherein,
R 1 is alkyl having 12 to 25 carbon atoms or alkylene having 12 to 25 carbon atoms,
R 2 and R 3 are independently —O—C(O)NHR, —O—C(O)—R, —O—Si(R) x (R′) 3-x , —O—C(R) x (R′) 3-x , or —O—C(O)—(CH 2 ) y —C(O)—OH,
R is alkyl having 1 to 12 carbon atoms, aryl having 5 to 12 carbon atoms, or aralkyl having 6 to 12 carbon atoms,
the substituent R may be substituted or unsubstituted with at least one substituent selected from the group consisting of alkyl having 1 to 6 carbon atoms, alkylene having 2 to 6 carbon atoms, and aryl having 5 to 12 carbon atoms,
R′ is alkoxy having 1 to 6 carbon atoms,
x is an integer of 1 to 3, and
y is an integer of 1 to 4,
wherein said composition is curable by UV irradiation.
2. The composition of claim 1 , wherein R 1 is C 15 H 31-2n , and n is one of 1 to 3,
R 2 and R 3 are independently —O—C(O)NHR, and
R is aralkyl having 6 to 12 carbon atoms, which is substituted or unsubstituted with alkyl having 1 to 12 carbon atoms or alkylene having 2 to 6 carbon atoms.
3. The composition of claim 1 , wherein R 1 is (CH 2 ) 14 CH 3 , (CH 2 ) 7 CH═CH(CH 2 ) 5 CH 3 , (CH 2 ) 7 CH═CHCH 2 CH═CH(CH 2 ) 2 CH 3 , (CH 2 ) 7 CH═CHCH 2 CH═CHCH═CHCH 3 , or (CH 2 ) 7 CH═CHCH 2 CH═CHCH 2 CH═CH 2 ,
R 2 and R 3 are independently —O—C(O)NHR, and
R is aralkyl having 6 to 12 carbon atoms, which is substituted or unsubstituted with alkyl having 1 to 8 carbon atoms, benzyl or alkylene having 2 to 4 carbon atoms.
4. The composition of claim 1 , wherein the compound of Formula 1 is included at a content of 1 to 50 parts by weight.
5. The composition of claim 1 , wherein the oligomer includes
25 to 45 parts by weight of the urethane-based modified epoxy acrylate; and
10 to 25 parts by weight of the urethane acrylate.
6. The composition of claim 1 , wherein the acrylate monomer includes
25 to 35 parts by weight of the monofunctional acrylate monomer; and
7 to 15 parts by weight of the trifunctional acrylate monomer.
7. The composition of claim 1 , further comprising a photoinitiator.
8. The composition of claim 7 , wherein the photoinitiator is at least one selected from the group consisting of a benzophenone containing photoinitiator, diphenoxy benzophenone containing photoinitiator, an anthraquinone derivative, a xantone derivative, a thioxantone derivative, or a benzyl containing photoinitiator.
9. The composition of claim 7 , wherein the photoinitiator is included at a content of 0.1 to 10 parts by weight.
10. A surface-treated steel sheet, comprising:
a steel sheet; and
a coating layer formed by curing the composition for coating surface of steel sheet according to claim 1 on one or both surfaces of the steel sheet.
11. A surface-treated steel sheet, comprising:
a steel sheet; and
a coating layer formed by curing the composition for coating surface of steel sheet according to claim 3 on one or both surfaces of the steel sheet.
12. A surface-treated steel sheet, comprising:
a steel sheet; and
a coating layer formed by curing the composition for coating surface of steel sheet according to claim 3 on one or both surfaces of the steel sheet.
13. A surface-treated steel sheet, comprising:
a steel sheet; and
a coating layer formed by curing the composition for coating surface of steel sheet according to claim 5 on one or both surfaces of the steel sheet.
14. A composition for coating the surface of steel sheet, comprising:
a binder comprising an oligomer and a diluent, wherein the oligomer includes 25 to 45 parts by weight of the urethane-based modified epoxy acrylate, and 10 to 25 parts by weight of the urethane acrylate; and
a compound represented by Formula 1:
wherein,
R 1 is alkyl having 1 to 30 carbon atoms, alkylene having 2 to 30 carbon atoms, alkynyl having 2 to 30 carbon atoms, or aryl having 5 to 12 carbon atoms,
R 2 and R 3 are independently —O—C(O)NHR, —O—C(O)—R, —O—Si(R) x (R′) 3-x , —O—C(R) x (R′) 3-x , or —O—C(O)—(CH 2 ) y —C(O)—OH,
R is alkyl having 1 to 30 carbon atoms, alkylene having 2 to 30 carbon atoms, alkynyl having 2 to 30 carbon atoms, aryl having 5 to 12 carbon atoms, or aralkyl having 6 to 24 carbon atoms,
the substituent R may be substituted or unsubstituted with at least one substituent selected from the group consisting of alkyl having 1 to 12 carbon atoms, alkylene having 2 to 12 carbon atoms, alkynyl having 2 to 12 carbon atoms, and aryl having 5 to 12 carbon atoms,
R′ is alkoxy having 1 to 12 carbon atoms,
x is an integer of 1 to 3, and
y is an integer of 1 to 4,
wherein said composition is curable by UV irradiation.
15. A surface-treated steel sheet, comprising:
a steel sheet; and
a coating layer formed by curing the composition for coating surface of steel sheet according to claim 14 on one or both surfaces of the steel sheet.