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 surgical instrument for receiving electrosurgical energy, wherein at least part of said instrument is insulated with a coating having a substantially non-stick coating formulation comprising:
 silica;   at least one inorganic filler; and   a strong 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.   
     
     
         2 .- 18 . (canceled) 
     
     
         19 . The surgical instrument of  claim 1 , wherein the instrument is a blade. 
     
     
         20 . The surgical instrument of  claim 19 , wherein at least part of the coating is between about 0.001 and 0.1 inches thick. 
     
     
         21 . The surgical instrument of  claim 20 , wherein at least part of the coating is between about 0.002 and 0.010 inches thick. 
     
     
         22 . The surgical instrument of  claim 19 , wherein a portion of the blade has an impedance of less than about 5,000 ohms, said portion comprised of an edge exposed through the coating. 
     
     
         23 . The surgical instrument of  claim 19 , wherein at least a portion of said blade is composed of stainless steel. 
     
     
         24 . The surgical instrument of  claim 1 , wherein the instrument has at least a portion with an impedance less than about 5,000 ohms. 
     
     
         25 . The surgical instrument of  claim 24 , wherein at least part of the coating is between about 0.001 and 0.1 inches thick. 
     
     
         26 . The surgical instrument of  claim 1 , wherein said strong base is potassium hydroxide. 
     
     
         27 . The surgical instrument of  claim 1 , wherein said coating formulation has a pH of at least 12.5 during at least part of a formulation process. 
     
     
         28 . The surgical instrument of  claim 1 , the coating formulation further comprising:
 at least one alkoxy silane.   
     
     
         29 . The surgical instrument of  claim 28 , wherein said at least one alkoxy silane of the formulation comprises at least one alkylalkoxysilane. 
     
     
         30 . The surgical instrument of  claim 29 , wherein said at least one alkylalkoxysilane of the formulation includes at least one halogen being at least one of:
 chlorine; and   fluorine.   
     
     
         31 . The surgical instrument of  claim 30 , wherein said at least one alkylalkoxysilane of the coating formulation is selected from a group consisting of:
 fluoroalkylalkoxysilanes; and   chloroalkylalkoxysilanes.   
     
     
         32 . The surgical instrument of  claim 31  wherein said fluoroalkylalkoxysilane is between 5 and 15 weight percent of the coating formulation. 
     
     
         33 . The surgical instrument of  claim 1 , 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.   
     
     
         34 . The surgical instrument of  claim 31 , wherein said at least one alkylalkoxysilane of the coating formulation comprises at least one hydrolyzable inorganic alkylsilyl group. 
     
     
         35 . The surgical instrument of  claim 34 , wherein said hydrolyzable inorganic alkylsilyl of the coating formulation group is selected from a group consisting of:
 a methoxysilyl group; and   an ethoxysilyl group.   
     
     
         36 . The surgical instrument of  claim 1 , wherein said coating formulation comprises at least 10 weight percent of a solution comprising a colloidal silicate. 
     
     
         37 . The surgical instrument of  claim 36 , wherein said solution of the coating formulation comprises an alkali metal silicate solution. 
     
     
         38 . The surgical instrument blade of  claim 19 , wherein said coating formulation comprises at least 10 weight percent of a solution comprising a colloidal silicate. 
     
     
         39 . The surgical 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.   
     
     
         40 . The surgical instrument of  claim 1 , wherein said inorganic filler of the coating formulation comprises one or more materials that have at least 30 percent by weight A1 2O3 or SiO2 either alone or combined with other elements. 
     
     
         41 . The surgical instrument of  claim 1 , wherein said inorganic filler of the coating formulation comprises one or more materials that are clays from the smectite group of phyllosilicate minerals. 
     
     
         42 . The surgical instrument of  claim 41 , wherein said smectite clay is an onium ion treated clay. 
     
     
         43 . The surgical instrument of  claim 42 , wherein said onium ion treated clay is onium ion treated montmorillonite. 
     
     
         44 . The surgical instrument of  claim 1 , wherein said inorganic filler of the coating formulation comprises one or more materials from a group consisting of: talc, kaolin, mica, smectite, montmorillonite, sericite, and hectorite. 
     
     
         45 . The surgical instrument of  claim 1 , wherein said inorganic filler of the coating formulation has at least one filler material with at least one dimension, such as diameter, length, width, or particle size, having a mean value of less than about 200 micrometers. 
     
     
         46 . The surgical instrument of  claim 1 , the coating formulation further comprising:
 at least one fluoropolymer.   
     
     
         47 . The surgical instrument of  claim 46 , wherein said at least one fluoropolymer is at least one of PTFE and PFA. 
     
     
         48 . The surgical instrument of  claim 47 , wherein said at least one of PTFE and PFA is an aqueous dispersion of at least one of PTFE and PFA. 
     
     
         49 . The surgical instrument of  claim 1 , wherein the coating has a surface free energy of less than about 32 millinewtons/meter. 
     
     
         50 . A process of manufacturing a surgical instrument in which at least one apparatus metal component surface is coated at least in part with a material that produces a substantially non-stick coating formulation comprising:
 preparing a coating comprising:
 silica; 
 at least one inorganic filler; 
 at least one hydrolyzable inorganic alkylsilyl; and 
 a strong 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; 
   applying the coating to at least a portion of a one metal component surface;   drying the coating at about 60 to 200 degrees Fahrenheit;   curing the coated part at a temperature greater than about 350 degrees Fahrenheit.   
     
     
         51 . The process of  claim 50 , wherein said at least one hydrolyzable inorganic alkylsilyl contains at least one halogen. 
     
     
         52 . The process of  claim 51 , wherein said at least one halogen is comprised of at least one of:
 chlorine; and   fluorine.   
     
     
         53 . The process of  claim 50 , wherein said coating formulation has a pH of at least 12.5 during at least part of the formulation process.