Contact Lens

Abstract

A contact lens formed of a composition comprising the reaction product of: A) at least 10 weight percent, based on the total composition weight excluding solvent, of at least one silicone-containing monomer of the formula I: where n is from 1 to 3, m is from 9 to 15, each a independently is C 1-4 alkyl, and each b independently is C 1-4 alkyl; B) at least 10 weight percent, based on the total composition weight excluding solvent, of 3-methacryloxypropyl tris(trimethylsiloxy) silane; C) N-vinyl pyrrolidone; and D) at least one other non-ionic hydrophilic monomer wherein the combined amount of A) and B) is at least 20 weight percent based on the total composition weight excluding solvent, and wherein the N-vinyl pyrrolidone (NVP) is present in such an amount that the reaction product comprises polyvinyl pyrrolidone (PVP) homopolymer.

1 . A contact lens formed of a composition comprising the reaction product of:
 A) at least 10 weight percent, based on the total composition weight excluding solvent, of at least one silicone-containing monomer of the formula I:   
     
       
         
         
             
             
         
       
       where n is from 1 to 3, m is from 9 to 15, each a independently is C 1-4  alkyl, and each b independently is C 1-4  alkyl; 
       B) at least 10 weight percent, based on the total composition weight excluding solvent, of 3-methacryloxypropyl tris(trimethylsiloxy) silane; 
       C)N-vinyl pyrrolidone; and 
       D) at least one other non-ionic hydrophilic monomer, wherein the combined amount of A) and B) is at least 20 weight percent based on the total composition weight excluding solvent, and wherein the N-vinyl pyrrolidone (NVP) is present in such an amount that the reaction product comprises polyvinyl pyrrolidone (PVP) homopolymer. 
     
   
   
       2 . A contact lens formed of a composition comprising the reaction product of:
 A) at least 10 weight percent, based on the total composition weight excluding solvent, of at least one silicone-containing monomer of Formula I   
     
       
         
         
             
             
         
       
       where n is from 1 to 3, m is from 9 to 15, each a independently is C 1-4  alkyl, and each b independently is C 1-4  alkyl; 
       B) at least 10 weight percent, based on the total composition weight excluding solvent, of 3-methacryloxypropyl tris(trimethylsiloxy) silane; 
       C) from 20 to 60 weight percent, based on the total composition weight excluding solvent, N-vinyl pyrrolidone; 
       D) from 2 to 10 weight percent, based on the total composition weight excluding solvent, of at least one other non-ionic hydrophilic monomer; 
       E) from 0.2 to 2 weight percent, based on the total composition weight excluding solvent, of a free radical initiator; and 
       F) from 0.2 to 5 weight percent, based on the total composition weight excluding solvent, of a cross-linking agent, 
       wherein A) and B) are present in a combined amount of at least 20 weight percent based on the total composition weight excluding solvent. 
     
   
   
       3 . A contact lens as claimed in  claim 1  or  claim 2 , wherein D) comprises at least one of 2-hydroxyethyl methacrylate and N,N-dimethylacrylamide. 
   
   
       4 . A contact lens as claimed in  claim 1 , additionally comprising up to 3 weight percent based on the total composition weight excluding solvent, of acrylic or methacrylic acid. 
   
   
       5 . A contact lens as claimed in  claim 1 , wherein A) comprises trimethylsilyl methacryloxypropyl (polydimethyl siloxane). 
   
   
       6 . A contact lens as claimed in  claim 2 , wherein the free radical initiator is AZBN. 
   
   
       7 . A contact lens as claimed in  claim 2 , wherein the cross-linker is tetraethyleneglycol methacrylate. 
   
   
       8 . A method of making a contact lens comprising the steps of: 
     mixing:
 A) at least 10 weight percent, based on the total composition weight excluding solvent, of at least one silicone-containing monomer of Formula I 
 
     
       
         
         
             
             
         
       
       where n is from 1 to 3, m is from 9 to 15, each a independently is C 1-4  alkyl, and each b independently is C 1-4  alkyl; 
       B) at least 10 weight percent, based on the total composition weight excluding solvent, of 3-methacryloxypropyl tris(trimethylsiloxy) silane; 
       C) from 20 to 60 weight percent, based on the total composition weight excluding solvent, N-vinyl pyrrolidone; 
       D) from 2 to 10 weight percent, based on the total composition weight excluding solvent, of at least one other non-ionic hydrophilic monomer; 
       E) from 0.2 to 2 weight percent, based on the total composition weight excluding solvent, of a free radical initiator; and 
       F) from 0.2 to 5 weight percent, based on the total composition weight excluding solvent, of a cross-linking agent, 
       wherein A) and B) are present in a combined amount of at least 20 weight percent based on the total composition weight excluding solvent addition of a solvent in an amount of from 15 to 30 weight percent based on the weight of reactants, wherein the solvent comprises at least one primary alcohol; 
       adding the mixture into a contact lens mould; and 
       curing the reaction mixture to form a contact lens. 
     
   
   
       9 . A method as claimed in  claim 8 , wherein the solvent does not contain any secondary or tertiary alcohols. 
   
   
       10 . A method as claimed in  claim 8 , wherein the solvent comprises ethanol and/or decanol and/or propanol. 
   
   
       11 . A method as claimed in  claim 8 , wherein, the solvent comprises at least one primary alcohol and at least one additional solvent which is more hydrophobic than the primary alcohol, and which is present in an amount of from 20 to 50 weight percent of the solvent. 
   
   
       12 . A method as claimed  claim 11 , wherein the additional solvent is one or more of hexanol, octanol, decanol and ethyl acetate. 
   
   
       13 . A method as claimed in  claim 12 , wherein the solvent comprises a mixture of ethanol and at least one of hexanol, octanol, decanol and ethyl acetate. 
   
   
       14 . A method of making a contact lens comprising the reaction product of at least one silicone-containing monomer and at least one hydrophilic monomer, wherein the method comprises the step of incorporating in the reaction mixture from 15 to 30 weight percent, based on 100 weight percent of the reactants, of a mixed solvent, wherein the mixed solvent comprises ethanol and a co-solvent in an amount of at least 20 weight percent based on the total amount of solvent, wherein the co-solvent is at least one of hexanol, octanol, decanol and ethyl acetate. 
   
   
       15 . A contact lens formed of the reaction product of a composition comprising trimethylsilyl methacryloxypropyl (polydimethyl siloxane).