Coating suitable for surgical instruments

Abstract

A coating and devices using the coating are provided. The coating is applied in liquid form and dried or otherwise cured to form a durable adherent coating resistant to high temperatures and having optional hydrophobic properties. The coating formulation contains an aqueous formulation of silica, one or more fillers, and sufficient base, (e.g., potassium hydroxide), to have a pH exceeding about 10.5 during at least part of the formulation process. The formulation may contain a compound(s) that affects surface free energy, energy to make the cured coating hydrophobic. Such compounds include silanes containing halogens (e.g., fluorine or chlorine) and in particular silanes containing one or more hydrolyzable groups attached to at least one silicon atom and a group containing one or more halogens (e.g., chlorine or fluorine). A medical instrument (e.g., electrosurgical instrument) may be at least partially covered by a coating using the formulation.

1 . A medical instrument have a surface coated with a coating formulation comprising:
 silica;   at least one inorganic filler; and   a base in an amount so that the coating formulation has a pH of at least 10.5 during at least part of a formulation process, wherein said base comprises potassium hydroxide.   
   
   
       2 . The medical instrument coating formulation of  claim 1 , wherein said coating formulation comprises a solution including water and at least 20 weight percent of said potassium hydroxide. 
   
   
       3 . The medical instrument of  claim 1 , wherein the silica of the coating formulation comprises at least one of:
 colloidal silica; and   amorphous silica.   
   
   
       4 . The medical instrument of  claim 1 , the coating formulation further comprising:
 at least one alkoxy silane.   
   
   
       5 . The medical instrument of  claim 4 , wherein said at least one alkoxy silane of the coating formulation comprises:
 at least one alkylalkoxysilane.   
   
   
       6 . The medical instrument of  claim 5 , wherein said at least one alkylalkoxysilane of the coating formulation includes at least one halogen. 
   
   
       7 . The medical instrument of  claim 6 , wherein said at least one halogen of the coating formulation includes at least one of:
 chlorine; and   fluorine.   
   
   
       8 . The medical instrument of  claim 7 , wherein said at least one alkylalkoxysilane of the coating formulation is selected from a group consisting of:
 fluoroalkyalkoxysilanes; and   chloroalkyalkoxysilanes.   
   
   
       9 . The medical instrument of  claim 8 , wherein said at least one alkylalkoxysilane of the coating formulation comprises at least one hydrolyzable inorganic alkylsilyl group. 
   
   
       10 . The medical instrument of  claim 9 , wherein said hydrolyzable inorganic alkylsilyl of the coating formulation group is selected from a group consisting of:
 a methoxysilyl group; and   an ethoxysilyl group.   
   
   
       11 . The medical instrument of  claim 6 , wherein said at least one alkylalkoxysilane of the coating formulation comprises at least one of the following:
 at least one straight halogenalkyl chain; and   at least one branched halogenalkyl chain.   
   
   
       12 . The medical instrument of  claim 11 , wherein said at least one alkylalkoxysilane of the coating formulation comprises at least one of the following:
 at least one chloroalkyl chain; and   fluoroalkyl chain.   
   
   
       13 . The medical instrument of  claim 4 , the coating formulation further comprising at least one of the following:
 water;   a surfactant; and   a solid.   
   
   
       14 . The medical instrument of  claim 4 , wherein said coating formulation comprises fumed silica. 
   
   
       15 . The medical instrument of  claim 1 , the coating formulation further comprising at least one of the following:
 a material including a fluorinated carbon chain; and   a material including at least partially hydrolyzed fluorinated silanes; and   a material including at least partially cross-linked hydrolyzed silanes.   
   
   
       16 . The medical instrument of  claim 15 , wherein the base material of the coating formulation comprises:
 potassium hydroxide.   
   
   
       17 . The medical instrument of  claim 1 , wherein said coating formulation comprises at least 10 weight percent of a solution comprising a colloidal silicate. 
   
   
       18 . The medical instrument of  claim 17 , wherein said solution of the coating formulation comprises an alkali metal silicate solution. 
   
   
       19 . The medical instrument of  claim 17 , wherein said solution of the coating formulation comprises at least 50 weight percent silica. 
   
   
       20 . The medical instrument of  claim 17 , wherein an average particle size of said colloidal silicate of the coating formulation is between 5 nm and 100 nm. 
   
   
       21 . The medical instrument of  claim 1 , wherein said inorganic filler of the coating formulation comprises at least one metal and at least one non-metal material selected from a group consisting of:
 aluminum oxides;   zirconium nitrides;   zirconium carbides;   boron carbides;   silicon oxides;   magnesium-zirconium oxides;   zirconium-silicon oxides;   titanium oxides;   tantalum oxides;   tantalum nitrides;   tantalum carbides;   silicon nitrides;   silicon carbides;   tungsten carbides;   titanium nitrides;   titanium carbides;   nibobium nitrides;   niobium carbides;   vanadium nitrides;   vanadium carbides; and   hydroxyapatite.   
   
   
       22 . The medical instrument of  claim 1 , wherein the surface of the medical instrument is a metallic surface. 
   
   
       23 . The medical instrument of  claim 22 , wherein the metallic surface of the medical instrument comprises stainless steel. 
   
   
       24 . The medical instrument of  claim 23 , wherein the medical instrument is an electrosurgical instrument. 
   
   
       25 . The medical instrument of  claim 24 , wherein the coating formulation further comprises at least one of the following:
 a material including a fluorinated carbon chain; and   a material including at least partially hydrolyzed fluorinated silanes; and   a material including at least partially cross-linked hydrolyzed silanes.   
   
   
       26 . The medical instrument of  claim 25 , wherein said coating formulation comprises a solution including water and at least 20 weight percent of said potassium hydroxide. 
   
   
       27 . The medical instrument of  claim 26 , wherein said coating formulation comprises at least 10 weight percent of a solution comprising a colloidal silicate.