Photocurable composition suitable for rust prevention of a threaded joint for steel pipes
View Patent ↗A thin and highly transparent coating having excellent air tightness, adhesion to a substrate, lubricating properties, galling resistance, and corrosion resistance is formed on the surface of a metal substrate and particularly on the surface of a threaded joint which is used for connection of oil country tubular goods. A photocurable composition comprising (A) a photocurable (meth)acrylate resin, (B) a (meth)acrylate monomer selected from a monofunctional (meth)acrylate monomer and a difunctional (meth)acrylate monomer, (C) a trifunctional or higher multifunctional (meth)acrylate monomer, (D) a photopolymerization initiator, (E) a benzotriazole anticorrosive agent, (F) an anticorrosive pigment selected from a phosphate anticorrosive pigment and calcium ion-exchanged silica, and (G) a phosphate ester is used to form a photocured coating.
1. A photocurable composition consisting essentially of:
(A) a photocurable (meth)acrylate resin,
(B) a (meth)acrylate monomer selected from a monofunctional (meth)acrylate monomer and a difunctional (meth)acrylate monomer, said monofunctional (meth)acrylate monomer being selected from the group consisting of 2-ethylhexyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, methyltriglycol (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth)acrylate, and lauryl (meth)acrylate,
(C) a trifunctional or higher multifunctional (meth)acrylate monomer,
(D) a photopolymerization initiator,
(E) a benzotriazole anticorrosive agent,
(F) an anticorrosive pigment selected from a phosphate anticorrosive pigment and calcium ion-exchanged silica, and
(G) a phosphate ester.
2. A photocurable composition as set forth in claim 1 wherein the phosphate ester (G) is a (meth)acrylate having a phosphate group in the molecule.
3. A photocurable composition as set forth in claim 1 wherein the photocurable (meth)acrylate resin (A) is at least one member selected from polyester (meth)acrylate, epoxy (meth)acrylate, polyether (meth)acrylate, and polyurethane (meth)acrylate.
4. A photocurable composition as set forth in claim 1 containing, in mass parts, 5-50 parts of component (A), 5-50 parts of component (B), 5-30 parts of component (C), 1-15 parts of component (D), 0.1-5 parts of component (E), 1-10 parts of component (F), and 1-5 parts of component (G), wherein the total of components (A)-(G) is 100 parts by mass.
5. A photocurable composition consisting essentially of:
(A) a photocurable (meth)acrylate resin,
(B) a (meth)acrylate monomer selected from a monofunctional (meth)acrylate monomer and a difunctional (meth)acrylate monomer, said monofunctional (meth)acrylate monomer being selected from the group consisting of 2-ethylhexyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, methyltriglycol (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth)acrylate, and lauryl (meth)acrylate,
(C) a trifunctional or higher multifunctional (meth)acrylate monomer,
(D) a photopolymerization initiator,
(E) a benzotriazole anticorrosive agent,
(F) an anticorrosive pigment selected from a phosphate anticorrosive pigment and calcium ion-exchanged silica,
(G) a phosphate ester, and further containing a lubricant.
6. A photocurable composition consisting essentially of:
(A) a photocurable (meth)acrylate resin,
(B) a (meth)acrylate monomer selected from a monofunctional (meth)acrylate monomer and a difunctional (meth)acrylate monomer, said monofunctional (meth)acrylate monomer being selected from the group consisting of 2-ethylhexyl (meth)acrylate, phenoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, methyltriglycol (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth)acrylate, and lauryl (meth)acrylate,
(C) a trifunctional or higher multifunctional (meth)acrylate monomer,
(D) a photopolymerization initiator,
(E) a benzotriazole anticorrosive agent,
(F) an anticorrosive pigment selected from a phosphate anticorrosive pigment and calcium ion-exchanged silica,
(G) a phosphate ester, and further containing a fluorescent brightening agent.
7. The use of a photocurable composition as set forth in claim 1 as a material for forming a rust-preventing coating on a threaded joint for steel pipes.
8. A photocured coating formed from a photocurable composition as set forth in claim 1 .
9. A photocured coating as set forth in claim 8 having a turbidity of at most 40%.
10. A metal substrate with a photocured coating having a photocured coating as set forth in claim 8 on the surface of the metal substrate.
11. A threaded joint for steel pipes with a photocured coating having a photocured coating as set forth in claim 8 on the surface of a pin and/or a box of the threaded joint for steel pipes.
12. A rust-preventing method for a threaded joint for steel pipes including the steps of applying a photocurable composition as set forth in claim 1 on the surface of a pin and/or a box of a threaded joint for steel pipes and then irradiating the coated surface with active energy rays to cure the composition and form a photocured coating.
13. A method of manufacturing a threaded joint for steel pipes with a photocured coating including the steps of applying a photocurable composition as set forth in claim 1 on the surface of a pin and/or a box of a threaded joint for steel pipes and then irradiating the coated surface with active energy rays to cure the composition and form a photocured coating.