Method for treating the surface of a device for dispensing a fluid product

Abstract

A treatment method for treating the surface of a fluid dispenser device, said method comprising the step of using chemical grafting to form a thin film on at least one support surface of at least one component part that is in contact with said fluid, said thin film preventing interactions between said fluid and said component part.

1 . A treatment method for treating the surface of a fluid dispenser device, said method being characterized in that it comprises the step of using chemical grafting to form a thin film on at least one support surface of at least one component part that is in contact with said fluid, said thin film preventing interactions between said fluid and said component part. 
     
     
         2 . A method according to  claim 1 , wherein said grafting step comprises putting said surface that is in contact with the fluid into contact with a solution that includes at least one adhesive primer, said adhesive primer being a cleavable aryl salt, and at least one monomer or polymer selected from the group constituted by vinyl- or acrylic-terminated siloxanes and vinyl or acrylic monomers. 
     
     
         3 . A method according to  claim 1 , wherein said chemical grafting creates covalent bonds between the molecules of said thin film and said support surface. 
     
     
         4 . A method according to  claim 1 , wherein said chemical grafting is performed in an aqueous medium. 
     
     
         5 . A method according to  claim 1 , wherein the cleavable aryl salt is selected from the group constituted by: aryl diazonium salts; aryl ammonium salts; aryl phosphonium salts; aryl sulfonium salts; and aryl iodonium salts. 
     
     
         6 . A method according to  claim 1 , wherein the reducing agent is selected from the group constituted by: reducing metals that are possibly finely divided, such as iron, zinc, or nickel; a metal salt that is possibly in the form of a metallocene; and an organic reducing agent such as hypophosphorus acid, or ascorbic acid. 
     
     
         7 . A method according to  claim 1 , wherein said chemical-grafting step is initiated by chemical activation. 
     
     
         8 . A method according to  claim 7 , wherein said chemical activation is initiated by the presence of a reducing agent in the solution. 
     
     
         9 . A method according to  claim 1 , wherein vinyl- or acrylic-terminated siloxanes are selected from the group constituted by: vinyl- or acrylic-terminated polyalkylsiloxanes such as vinyl- or acrylic-terminated polymethylsiloxane; vinyl- or acrylic-terminated polydimethylsiloxane such as polydimethylsiloxane-acrylate (PDMS-acrylate); vinyl- or acrylic-terminated polyarylsiloxanes such as vinyl- or acrylic-terminated polyphenylsiloxane such as polyvinylphenylsiloxane; and vinyl- or acrylic-terminated polyarylalkylsiloxanes such as vinyl- or acrylic-terminated polymethylphenylsiloxane. 
     
     
         10 . A method according to  claim 1 , wherein the vinyl or acrylic monomer is selected from the group constituted by: vinyl acetate; acrylonitrile; methacrylonitrile; methyl methacrylate; ethyl methacrylate; butyl methacrylate; propyl methacrylate; hydroxyethyl methacrylate; hydroxpropyl methacrylate; glycidyl methacrylate; and derivatives thereof; acrylamides such as aminoethyl methacrylamides, propyl, butyl, pentyl, and hexyl; cyanoacrylates; diacrylates; dimethacrylates; triacrylates; trimethacrylates; tetraacrylates; tetramethacrylates; styrene and its derivatives; parachlorostyrene; pentafluorostyrene; N-vinyl pyrrolidone; 4-vinyl pyridine; 2-vinyl pyridine; vinyl, acryloyl, and methacryloyl halides; divinylbenzene. 
     
     
         11 . A method according to  claim 1 , wherein a potential difference is applied in said solution. 
     
     
         12 . A method according to  claim 11 , wherein the potential difference is applied by a generator that is connected to two electrodes that are identical or different and that are dipped in the solution during the dipping step. 
     
     
         13 . A method according to  claim 11 , wherein the potential difference is generated by a chemical cell. 
     
     
         14 . A method according to  claim 1 , wherein said component part, in particular a crimping cap, a spring, or a valve-forming ball, is made out of metal. 
     
     
         15 . A method according to  claim 1 , wherein said component part, in particular a piston or a gasket, is made out of a flexible material such as elastomer. 
     
     
         16 . A method according to  claim 1 , wherein said component part is made out of a synthetic material such as polyethylene or polypropylene. 
     
     
         17 . A method according to  claim 1 , wherein said component part, in particular a reservoir, is made out of glass. 
     
     
         18 . A method according to  claim 1 , wherein said thin film has a thickness that is less than 1 μm, preferably lying in the range 10 Å to 2000 Å. 
     
     
         19 . The use of a grafting method according to  claim 1 , in order to treat form a thin film on at least one support surface of at least one component part movable portion of a fluid dispenser device that is movable while said device is being actuated, said thin film having anti-friction properties that is in contact with said fluid, so as to prevent interactions between said fluid and said component part.