Method of modifying the surface of a solid polymer substrate and the product obtained

Abstract

A method of modifying the surface of a solid polymer substrate comprising the steps of a) generating radicals on the substrate surface by subjecting it to a gas plasma or by subjecting it to UV light, and b) treating the surface with a vapor of a monomer or a monomer mixture comprising cyano acrylate and/or isocyanate, where step b) starts before step a), simultaneously with step a), under step a), or follows immediately after step a), and a polymer substrate modified accordingly; a method of binding an organic binder material to a surface of a solid polymer substrate comprising the steps of modifying the surface of the substrate by said method, and bringing the organic material in contact with the surface of the substrate, and a polymer bonded to an organic material by the last mentioned method.

1. A method of modifying the surface of a solid polymer substrate comprising the steps of
 a) generating radicals on the substrate surface by subjecting it to a gas plasma or by subjecting it to ultraviolet light, and  
 b) treating the surface with a vapour of a monomer or a monomer mixture comprising cyano acrylate and/or isocyanate,  
 where step b) starts before step a), simultaneously with step a), during step a), or follows immediately after step a).  
 
     
     
       2. A method according to  claim 1 , wherein the monomer or monomer mixture comprises one or more of C 1 -C 10  2-alkyl cyano acrylate and diisocyanate. 
     
     
       3. A method according to  claim 2 , wherein the diisocyanate is toluene 2,4-diisocyanate. 
     
     
       4. A method according to  claim 1  wherein step b) comprises treatment of the surface with a monomer mixture comprising acrylic acid, methyl acrylate, 2-hydroxy-ethylacrylate, N-ethyl-2-methyl allylamine, glycidyl methacrylate, diallylamine, and/or other vinyl group containing monomers. 
     
     
       5. A method according to  claim 1 , wherein step b) comprises treatment of the surface with a monomer vapour comprising 60 mole % or more of 2-ethyl cyano acrylate vapour. 
     
     
       6. A method according to  claim 5 , wherein step b) comprises treatment of the surface with a monomer vapour comprising 90 mole % or more of 2-ethyl cyano acrylate vapour. 
     
     
       7. A method according to  claim 1 , wherein the monomer mixture prior to the vaporization consists essentially of 2-ethyl cyano acrylate, an acid having a partial vapour pressure in the plasma which is lower than the partial vapour pressure of 2-ethyl cyano acrylate, and up to 40 weight-% of another filler. 
     
     
       8. A method according to  claim 7 , wherein the acid is a polyphosphoric acid and is present prior to the vaporization in a concentration up to 10 weight-%. 
     
     
       9. A method according to  claim 1 , wherein the polymer substrate is a silicone rubber or a thermoplastic. 
     
     
       10. A method according to  claim 9 , wherein the polymer substrate is selected from the group consisting of a polytetra fluoroethylene (PTFE), tetra fluoroethylene hexa fluoropropylene copolymer (FEP), polyvinyl difluoride (PVDF), nylon 6,6, nylon 11, and polyvinyl chloride (PVC). 
     
     
       11. A method according to  claim 1 , wherein the polymer substrate is a polyolefin. 
     
     
       12. A method according to  claim 1 , wherein the polymer substrate is an injection moulded polymer component, a polymer fiber, a polymer thread or a polymer filler. 
     
     
       13. A method according to  claim 1 , wherein the generation of radicals on the substrate surface is obtained by subjecting the substrate to a gas plasma, and the gas is an inert gas. 
     
     
       14. A method according to  claim 1 , wherein step a) comprises the step of generating radicals by use of a gas plasma generated by excitation of the gas in a direct current (DC), audio frequency (Ar), radio frequency or microwave generated electric field. 
     
     
       15. A method according to  claim 1 , wherein the monomer pressure in step b) is between 0.1 and 100000 Pa. 
     
     
       16. A method according to  claim 15 , wherein step a) is carried out for more than 30 seconds, and step b) is started 10 to 30 seconds after step a). 
     
     
       17. A method according to  claim 1 , wherein the generation step a) is carried out for a period of between 0.01 and 1000 seconds, and the treatment step b) is carried out for a period of between 0.1 and 1000 seconds. 
     
     
       18. A method according to  claim 1 , wherein the temperature is the same under both step a) and step b). 
     
     
       19. A method according to  claim 18 , wherein the temperature under both step a) and step b) is between 250 and 450 K. 
     
     
       20. A method according to  claim 1 , wherein the total pressure under step a) is equal to the total pressure under step b). 
     
     
       21. A method according to  claim 20 , wherein the total pressure under step a) and step b) is between 0.2 and 10000 Pa. 
     
     
       22. A polymer substrate modified according to  claim 1 . 
     
     
       23. A method of binding an organic binder material to a surface of a solid polymer substrate comprising the steps of
 modifying the surface of the substrate by the method according to  claim 1 , and  
 bringing the organic material in contact with the surface of the substrate.  
 
     
     
       24. A method according to  claim 23 , herein wherein the organic binder material is a paint, an adhesive or another polymer material. 
     
     
       25. A polymer bonded to an organic material by the method according to  claim 23 . 
     
     
       26. A polymer composite material according to  claim 25 , wherein the polymer substrate is a polymer fiber, a polymer thread or a polymer filler, and the organic material is another polymer. 
     
     
       27. A polymer composite material according to  claim 26 , wherein the organic material is a polyester or an epoxy polymer.