Method for reducing friction

Abstract

The invention is directed to a method for reducing friction between at least two bodies. The method of the invention comprises providing a surface of at least one of said at least two solid bodies with a covalently bound coating, wherein said surface is to be contacted with another one of said at least two solid bodies, and wherein said coating comprising at least one polymer; and providing a liquid onto said coating.

1 . Method for reducing friction between at least two solid bodies, comprising
 providing a surface of at least one of said at least two solid bodies with a covalently bound coating, wherein said surface is to be contacted with another one of said at least two solid bodies, and wherein said coating comprising at least one polymer; and   providing a liquid onto said coating.   
     
     
         2 . Method according to  claim 1 , wherein said coating and said liquid are both hydrophilic. 
     
     
         3 . Method according to  claim 1 , wherein said polymer is selected from the group consisting of polyoxazoline, polyethylene glycol, polyvinylalcohol, polyvinylpyrrolidone, polyacrylamide, poly(meth)acrylic acid, polyethylene oxide-co-polypropylene oxide block copolymers, poly(vinylether), poly(N,N-dialkylacrylamide), polyelectrolytes, polyacyl alkylene imine, polyhydroxyalkylacrylates, polyols, polysaccharides, polypeptides, polyionic polymers, polyethyleneimine, polyvinylbenzyltrimethylammonium, polyaniline, sulphonated polyaniline, polypyrrole, polypyridinium, polythiophene-acetic acids, polystyrenesulphonic acids, polymers of zwitterionic molecules, and mixtures and copolymers thereof. 
     
     
         4 . Method according to  claim 1 , wherein said coating comprises a poly(acrylic acid) or a derivative thereof. 
     
     
         5 . Method according to  claim 1 , wherein said coating comprises a polyethylene glycol. 
     
     
         6 . Method according to  claim 1 , wherein said coating comprising a polyethylene glycol with a number average molecular weight of at least 5 000 g/mol. 
     
     
         7 . Method according to  claim 1 , wherein said coating is of hydrophobic nature. 
     
     
         8 . Method according to  claim 1 , wherein said polymer is selected from the group consisting of polysiloxanes, fluoropolymers, polystyrene, polyoxypropylene, polyvinylacetate, polyoxybutylene, (hydrogenated) polyisoprene or polybutadiene, polyvinylchloride, polyalkylacrylate, polyalkylmethacrylate, polyacrylonitrile, polypropylene, polyethylene, polytetrahydrofuran, polymethacrylates, polyacrylates, polysulphones, polyvinylethers, polypropylene oxide), and mixtures and copolymers thereof. 
     
     
         9 . Method according to  claim 1 , wherein said coating comprises at least two polymers layers. 
     
     
         10 . Method according to  claim 1 , wherein said coating has a thickness of 1 μm or less. 
     
     
         11 . Method according to  claim 1 , wherein said liquid is water or an aqueous medium. 
     
     
         12 . Method according to  claim 7 , wherein said liquid is an organic compound. 
     
     
         13 . Method according to  claim 7 , wherein said liquid is a silicone fluid. 
     
     
         14 . Method according to  claim 1 , wherein the amount of liquid is in the range of 0.05-10 g per gram of dry coating. 
     
     
         15 . Method according to  claim 1 , wherein said at least two solid bodies are of the same material or of different material. 
     
     
         16 . Method according to  claim 1 , wherein said at least two solid bodies comprise one of more materials selected from the group consisting of plastics, metals, alloys, glass, textiles, metal oxide, ceramics, wood, living tissue (skin), mucosal membranes, and combinations thereof. 
     
     
         17 . Method according to  claim 1 , wherein said polymer and said liquid are selected from the group consisting of poly(acrylic acid) polymer or derivatives thereof and water or an aqueous medium, poly(acrylic acid) polymer or derivatives thereof and silicone oil, poly(acrylic acid) polymer or derivatives thereof and C 6 -C 20  alkane, polyethylene glycol or derivatives thereof and water or an aqueous medium, polyethylene glycol or derivatives thereof and silicone oil, polyethylene glycol or derivatives thereof and C 6 -C 20  alkane, polysiloxane or derivatives thereof and water or an aqueous medium, polysiloxane or derivatives thereof and silicone oil, polysiloxane or derivatives thereof and C 6 -C 20  alkane, polyolefin or derivatives thereof and water or an aqueous medium, polyolefin or derivatives thereof and silicone oil, polyolefin or derivatives thereof and C 6 -C 20  alkane. 
     
     
         18 . Method according to  claim 17 , wherein said coating comprises at least two layers, wherein a first layer comprises poly(acrylic acid) polymer or a derivative thereof and a second layer on top of said first layer comprises the polymer as defined in  claim 17 . 
     
     
         19 . Method according to  claim 1 , wherein said coating has a thickness of 500 nm or less. 
     
     
         20 . Method according to  claim 1 , wherein said coating has a thickness of 100 nm or less. 
     
     
         21 . Method according to  claim 1 , wherein the amount of liquid is in the range of 0.1-5 g per gram of dry coating. 
     
     
         22 . Method according to  claim 1 , wherein the amount of liquid is in the range of 0.2-1 gram of dry coating.