Composition, threaded joint for pipes including solid lubricant coating formed from the composition, and method for producing the threaded joint for pipes
A threaded joint for pipes disclosed herein includes a pin and a box. The pin and the box each include a contact surface including a threaded portion and a metal contact portion. The threaded joint for pipes includes a solid lubricant coating on at least one of the contact surfaces of the pin and the box, the solid lubricant coating including a binder, a lubricant additive, an anti-rust additive, and a plasticizer.
1. A threaded joint for pipes, the threaded joint comprising a pin and a box each comprising a contact surface, the contact surface comprising a threaded portion and an unthreaded metal contact portion,
the threaded joint for pipes comprising a solid lubricant coating on at least one of the contact surfaces of the pin and the box,
the solid lubricant coating comprising:
a binder comprising at least one member selected from the group consisting of an ethylene vinyl acetate resin, a polyolefin resin, and a wax;
a lubricant additive;
an anti-rust additive; and
a plasticizer comprising at least one member selected from the group consisting of bis(2-ethylhexyl) sebacate, diisodecyl adipate, diisononyl adipate, bis(2-ethylhexyl) azelate, and tricresyl phosphate,
wherein the solid lubricant coating comprises the binder in an amount of 60 to 80 mass %, the lubricant additive in an amount of 10 to 25 mass %, the anti-rust additive in an amount of 2 to 10 mass %, and the plasticizer in an amount of 0.2 to 5 mass %.
2. The threaded joint for pipes according to claim 1 ,
wherein the lubricant additive comprises at least one member selected from the group consisting of earthy graphite, graphite fluoride, perfluoropolyether, and polytetrafluoroethylene,
wherein the anti-rust additive comprises at least one member selected from the group consisting of calcium ion-exchanged silica and aluminum phosphite, and
wherein the plasticizer comprises at least one member selected from the group consisting of bis(2-ethylhexyl) adipate and bis(2-ethylhexyl) sebacate.
3. The threaded joint for pipes according to claim 1 , wherein one of the contact surfaces of the pin and the box comprises the solid lubricant coating, and the other of the contact surfaces of the pin and the box comprises a corrosion protective solid coating comprising a UV-curable resin.
4. The threaded joint for pipes according to claim 3 , wherein a thickness of the corrosion protective solid coating is in a range of 5 to 50 μm.
5. The threaded joint for pipes according to claim 1 , wherein a thickness of the solid lubricant coating is in a range of 10 to 200 μm.
6. A composition for forming a solid lubricant coating on a threaded joint for pipes according to claim 1 , the composition comprising:
a binder;
a lubricant additive;
an anti-rust additive; and
a plasticizer.
7. The composition according to claim 6 , wherein the plasticizer comprises at least one selected from the group consisting of bis(2-ethylhexyl) adipate and bis(2-ethylhexyl) sebacate.
8. The composition according to claim 6 , wherein a content of the plasticizer is in a range of 0.2 to 5 mass %.
9. The composition according to claim 7 , wherein a content of the plasticizer is in a range of 0.2 to 5 mass %.
10. The composition according to claim 6 ,
wherein the binder comprises at least one selected from the group consisting of an ethylene vinyl acetate resin, a polyolefin resin, and a wax,
wherein the lubricant additive comprises at least one selected from the group consisting of earthy graphite, graphite fluoride, perfluoropolyether, and polytetrafluoroethylene, and
wherein the anti-rust additive comprises at least one selected from the group consisting of calcium ion-exchanged silica and aluminum phosphite.
11. The composition according to claim 7 ,
wherein the binder comprises at least one selected from the group consisting of an ethylene vinyl acetate resin, a polyolefin resin, and a wax,
wherein the lubricant additive comprises at least one selected from the group consisting of earthy graphite, graphite fluoride, perfluoropolyether, and polytetrafluoroethylene, and
wherein the anti-rust additive comprises at least one selected from the group consisting of calcium ion-exchanged silica and aluminum phosphite.
12. The composition according to claim 8 ,
wherein the binder comprises at least one selected from the group consisting of an ethylene vinyl acetate resin, a polyolefin resin, and a wax,
wherein the lubricant additive comprises at least one selected from the group consisting of earthy graphite, graphite fluoride, perfluoropolyether, and polytetrafluoroethylene, and
wherein the anti-rust additive comprises at least one selected from the group consisting of calcium ion-exchanged silica and aluminum phosphite.
13. The composition according to claim 9 ,
wherein the binder comprises at least one selected from the group consisting of an ethylene vinyl acetate resin, a polyolefin resin, and a wax,
wherein the lubricant additive comprises at least one selected from the group consisting of earthy graphite, graphite fluoride, perfluoropolyether, and polytetrafluoroethylene, and
wherein the anti-rust additive comprises at least one selected from the group consisting of calcium ion-exchanged silica and aluminum phosphite.
14. A method for producing a threaded joint for pipes according to claim 1 , the threaded joint comprising a pin and a box each comprising a contact surface, the contact surface comprising a threaded portion and an unthreaded metal contact portion, the method comprising:
applying the composition according to claim 6 to at least one of the contact surfaces of the pin and the box; and
solidifying the composition applied to the contact surface to form a solid lubricant coating.
15. The method according to claim 14 for producing the threaded joint for pipes, the method comprising:
applying the composition to one of the contact surfaces of the pin and the box;
solidifying the composition applied to the contact surface to form a solid lubricant coating;
applying a composition for forming a corrosion protective solid coating to the other of the contact surfaces of the pin and the box, the composition for forming the corrosion protective solid comprising a UV-curable resin; and
irradiating, with UV light, the contact surface having the composition for forming the corrosion protective solid coating applied thereto, to form the corrosion protective solid coating.
16. The method according to claim 14 for producing the threaded joint for pipes, the method further comprising:
subjecting the contact surface, to which the composition for forming the solid lubricant coating is to be applied, to a surface preparation treatment prior to application of the composition, the surface preparation treatment being at least one selected from the group consisting of a sand blasting treatment, a pickling treatment, a phosphate chemical conversion treatment, and a zinc alloy plating treatment.
17. The method according to claim 15 for producing the threaded joint for pipes, the method further comprising:
subjecting the contact surface, to which the composition for forming the solid lubricant coating is to be applied, to a surface preparation treatment prior to application of the composition, the surface preparation treatment being at least one selected from the group consisting of a sand blasting treatment, a pickling treatment, a phosphate chemical conversion treatment, and a zinc alloy plating treatment.
18. The method according to claim 16 for producing the threaded joint for pipes, wherein the surface preparation treatment comprises the zinc alloy plating treatment, and
the method further comprises a trivalent chromating treatment that is performed subsequent to the zinc alloy plating treatment and prior to the application of the composition for forming the solid lubricant coating, the trivalent chromating treatment being performed on at least one of the contact surfaces of the pin and the box, the at least one contact surface having been subjected to the zinc alloy plating treatment.
19. The method according to claim 17 for producing the threaded joint for pipes, wherein the surface preparation treatment comprises the zinc alloy plating treatment, and
the method further comprises a trivalent chromating treatment that is performed subsequent to the zinc alloy plating treatment and prior to the application of the composition for forming the solid lubricant coating, the trivalent chromating treatment being performed on at least one of the contact surfaces of the pin and the box, the at least one contact surface having been subjected to the zinc alloy plating treatment.