Cured lubricant for container coveyors
View Patent ↗Lubricants for containers and for conveyors for transporting containers are provided. The lubricants provide container and conveyor surfaces having low coefficients of friction. In one embodiment, the lubricants comprise a cured coating containing hydrophobic polymers and waxes.
1. A method for lubricating a conveyor for transporting a container, the method comprising applying a liquid composition to at least a portion of a conveyor part that comes into contact with the container and allowing the liquid composition to dry into a solid or semi-solid coating to form a substantially water-repellent, lubricating coating on at least a portion of the conveyor part, the liquid composition comprising at least one hydrophobic polymer, at least one alkali soluble resin and at least one wax, wherein at least one of the hydrophobic polymer or the alkali soluble resin is polymerized from monomers that include (a) styrenic monomers and (b) at least one monomer selected from the group consisting of acrylate monomers, methacrylate monomers, methacrylic acid monomers and acrylic acid monomers.
2. The method of claim 1 , wherein the coating comprises at least 10 weight percent wax based on the solid material content of the coating.
3. The method of claim 1 , wherein the coating comprises greater than 50 weight percent wax based on the solid material content of the coating.
4. The method of claim 1 , wherein the coating comprises at least 40 weight percent of the at least one hydrophobic polymer based on the solid material content of the coating.
5. The method of claim 1 , wherein the at least one hydrophobic polymer is polymerized from styrenic and acrylate or methacrylate monomers.
6. The method of claim 5 , wherein the alkali soluble resin is polymerized from styrenic and acrylic acid or methacrylic acid monomers.
7. The method of claim 1 , wherein the liquid composition further comprises a fluoropolymer.
8. The method of claim 1 , wherein the wax comprises carnauba wax.
9. The method of claim 1 , wherein the liquid composition further comprises at least one additive selected from defoaming agents, anti-microbial agents, pigments, surfactants, wetting agents, and Zn oxide.
10. The method of claim 1 further comprising reapplying the liquid composition to at least a portion of the conveyor part to repair the lubricating coating.
11. The of claim 1 , wherein the lubricating coating, as applied, has a coefficient of friction of less than 0.15, as measured by a short track conveyor test.
12. The method of claim 11 , wherein the lubricating coating, as applied, has a coefficient of friction of less than about 0.14 as measured by a short track conveyor test.
13. The method of claim 1 , wherein the wax makes up at least 5 weight percent of the coating based on the solid material content of the coating.
14. The method of claim 1 , wherein the alkali soluble resin has a number average molecular weight of no more than about 20,000 and the hydrophobic polymer has a number average molecular weight of at least about 30,000.
15. The method of claim 1 , wherein the ratio of the alkali soluble resin to the hydrophobic polymer is from about 70:30 to 30:70.
16. A conveyor for transporting a container, at least a portion of a part of the conveyor coated with a solid or semi-solids, substantially water-repellent, lubricating coating comprising at least one hydrophobic polymer, at least one alkali soluble resin and at least one wax, wherein at least one of the hydrophobic polymer or the alkali soluble resin is polymerized from monomers that include (a) styrenic monomers and (b) at least one monomer selected from the group consisting of acrylate monomers, methacrylate monomers, methacrylic acid monomers and acrylic acid monomers.
17. The conveyor of claim 16 wherein the coating has a coefficient of friction of less than 0.15, as measured by a short track conveyor test.
18. The method of claim 1 , wherein the styrenic monomers are selected from the group consisting of styrene and methyl styrene monomers, and the acrylate monomers are butyl acrylate monomers.
19. The method of claim 1 , wherein the at least one hydrophobic polymer is polymerized from styrene, methyl styrene, butyl acrylate, and methacrylic acid and the at least one alkali soluble resin is polymerized from styrene, methyl styrene, and acrylic acid.
20. The conveyor of claim 16 , wherein the at least one hydrophobic polymer is polymerized from styrene and acrylate or methacrylate monomers.
21. The conveyor of claim 20 , wherein the alkali soluble resin is polymerized from styrene and acrylic acid or methacrylic acid monomers.
22. The conveyor of claim 16 , wherein the styrenic monomers are selected from the group consisting of styrene and methyl styrene monomers, the acrylate monomers are butyl acrylate monomers, and the methacrylate monomers are methacrylate monomers.
23. The conveyor of claim 16 , wherein the at least one hydrophobic polymer is polymerized from styrene, methyl styrene, butyl acrylate, and methacrylic acid and the at least one alkali soluble resin is polymerized from styrene, methyl styrene, and acrylic acid.
24. A method for lubricating a conveyor for transporting a container, the method comprising applying a liquid composition to at least a portion of a conveyor part that comes into contact with the container and allowing the liquid composition to dry into a solid or semi-solid coating to form a substantially water-repellent, lubricating coating on at least a portion of the conveyor part, the liquid composition comprising at least one hydrophobic polymer, at least one alkali soluble resin and at least one wax, wherein the at least one hydrophobic polymer and the at least one alkali soluble resin do not undergo polymerization or crosslinking after application to the conveyor part.
25. The method of claim 24 , wherein the coating comprises at least 10 weight percent wax based on the solid material content of the coating.
26. The method of claim 24 , wherein the coating comprises greater than 50 weight percent wax based on the solid material content of the coating.
27. The method of claim 24 , wherein the coating comprises at least 40 weight percent of the at least one hydrophobic polymer based on the solid material content of the coating.
28. The method of claim 24 , wherein the wax comprises carnauba wax.
29. The method of claim 24 , wherein the liquid composition further comprises at least one additive selected from defoaming agents, anti-microbial agents, pigments, surfactants, wetting agents, and Zn oxide.
30. The method of claim 24 , wherein the coating, as applied, has a coefficient of friction of less than about 0.14 as measured by a short track conveyor test.
31. The method of claim 24 , wherein the alkali soluble resin has a number average molecular weight of no more than about 20,000 and the hydrophobic polymer has a number average molecular weight of at least about 30,000.
32. The method of claim 24 , wherein the ratio of the alkali soluble resin to the hydrophobic polymer is from about 70:30 to 30:70.