Epoxy sizing composition for filament winding

Abstract

A sizing composition containing an epoxy film former, a silane package that includes an aminosilane coupling agent and an epoxy silane coupling agent, a cationic lubricant, a non-ionic lubricant, an antistatic agent, and at least one acid is provided. The epoxy resin emulsion includes a low molecular weight liquid epoxy resin and one or more surfactants. The epoxy resin preferably has an epoxy equivalent weight of from about 185 to about 192. The sizing composition may optionally contain polyurethane or epoxy/polyurethane film former. The sizing composition may be used to size glass fibers used in filament winding applications to form reinforced composite articles with improved mechanical properties, wet tensile properties, improved resistance to cracking, and improved processing characteristics. The sizing composition also provides improved processing parameters such as low fuzz and reduced drag.

1 . An aqueous sizing composition comprising: 
 an epoxy resin emulsion containing a liquid epoxy resin having an epoxy equivalent weight of from about 180 to about 210 and at least one surfactant;    a silane package including at least one aminosilane coupling agent and at least one epoxy silane coupling agent;    a cationic lubricant;    a non-ionic lubricant;    an antistatic agent;    at least one organic acid; and    a boron-containing compound.    
     
     
         2 . The aqueous sizing composition of  claim 1 , wherein said epoxy equivalent weight is about 185 to about 192.  
     
     
         3 . The aqueous sizing composition of  claim 1 , wherein said at least one organic acid is selected from at least one of acetic acid, formic acid, succinic acid and citric acid.  
     
     
         4 . The aqueous sizing composition of  claim 3 , wherein said boron-containing compound is selected from at least one of boric acid, boron oxide, sodium tetraborate, potassium metaborate, potassium tetraborate, ammonium biborate, ammonium tetrafluoroborate, butylammonium tetrafluoroborate, calcium tetrafluoroborate, lithium fluoroborate, potassium tetrafluoroborate, sodium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate and zinc tetrafluoroborate.  
     
     
         5 . The aqueous sizing composition of  claim 1 , further comprising at least one member selected from at least one of a polyurethane film former and an epoxy/polyurethane film former.  
     
     
         6 . The aqueous sizing composition of  claim 1 , wherein said epoxy resin emulsion is present in said sizing composition in an amount of from about 60 to about 90% by weight solids, said aminosilane coupling agent is present in said sizing composition in an amount of from about 0.4 to about 0.8% by weight solids, said epoxy silane coupling agent is present in said sizing composition in an amount of from about 10 about 20% by weight solids, said non-ionic lubricant is present in said sizing composition in an amount of from about 6 to about 10% by weight solids, said cationic lubricant and antistatic agent are present in said sizing composition in an amount of from about 0.4 to about 0.8% by weight solids, said at least one organic acid is present in said sizing composition in an amount of from about 0.4 to about 1.0% by weight solids and said boron-containing compound is present in said sizing composition in an amount of from about 0.2 to about 3.0% by weight solids.  
     
     
         7 . The aqueous sizing composition of  claim 6 , wherein said aminosilane coupling agent is aminopropyltriethoxysilane, said epoxy silane coupling agent is γ-glycidoxypropyltrimethoxysilane, and said boron containing compound is boric acid.  
     
     
         8 . A glass fiber at least partially coated with a sizing composition comprising: 
 an epoxy resin emulsion containing a liquid epoxy resin having an epoxy equivalent weight of from about 180 to about 210 and at least one surfactant;    a silane package including at least one aminosilane coupling agent and at least one epoxy silane coupling agent;    a cationic lubricant;    a non-ionic lubricant;    an antistatic agent;    at least one organic acid; and    a boron-containing compound.    
     
     
         9 . The glass fiber of  claim 8 , wherein said aminosilane coupling agent is aminopropyltriethoxysilane, said epoxy silane coupling agent is γ-glycidoxypropyltrimethoxysilane, and said boron containing compound is boric acid.  
     
     
         10 . The glass fiber of  claim 8 , wherein said at least one surfactant includes: 
 a block copolymer of ethylene oxide and propylene oxide; and    a polyoxyethylene-polyoxypropylene block copolymer.    
     
     
         11 . The glass fiber of  claim 10 , wherein said boron-containing compound is selected from at least one of boric acid, boron oxide, sodium tetraborate, potassium metaborate, potassium tetraborate, ammonium biborate, ammonium tetrafluoroborate, butylammonium tetrafluoroborate, calcium tetrafluoroborate, lithium fluoroborate, potassium tetrafluoroborate, sodium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate and zinc tetrafluoroborate; and 
 wherein said at least one organic acid is selected from the group consisting of acetic acid, formic acid, succinic acid and citric acid.    
     
     
         12 . The glass fiber of  claim 8 , wherein said epoxy resin emulsion is present in said sizing composition in an amount of from about 60 to about 90% by weight solids, said aminosilane coupling agent is present in said sizing composition in an amount of from about 0.4 to about 0.8% by weight solids, said epoxy silane coupling agent is present in said sizing composition in an amount of from about 10 to about 20% by weight solids, said non-ionic lubricant is present in said sizing composition in an amount of from about 6 to about 10% by weight solids, said cationic lubricant and antistatic agent are present in said sizing composition in an amount of from about 0.4 to about 0.8% by weight solids, said at least one organic acid is present in said sizing composition in an amount of from about 0.4 to about 1.0% by weight solids and said boron-containing compound is present in said sizing composition in an amount of from about 0.2 to about 3.0% by weight solids.  
     
     
         13 . The glass fiber of  claim 12 , wherein said epoxy equivalent weight is from about 185 to about 192.  
     
     
         14 . A reinforced composite article comprising: 
 a plurality of glass fibers at least partially coated with a sizing composition including: 
 an epoxy resin emulsion containing a liquid epoxy resin having an epoxy equivalent weight of from about 180 to about 210 and at least one surfactant;  
 a silane package including at least one aminosilane coupling agent and at least one epoxy silane coupling agent;  
 a cationic lubricant;  
 a non-ionic lubricant;  
 an antistatic agent;  
 at least one organic acid; and  
 a boron-containing compound.  
   
     
     
         15 . The reinforced composite article of  claim 14 , wherein said epoxy has an epoxy equivalent weight of about 185 to about 192.  
     
     
         16 . The reinforced composite article of  claim 15 , wherein said aminosilane coupling agent is aminopropyltriethoxysilane, said epoxy silane coupling agent is γ-glycidoxypropyltrimethoxysilane, and said boron containing compound is boric acid.  
     
     
         17 . The reinforced composite article of  claim 14 , wherein said at least one organic acid is selected from the group consisting of acetic acid, formic acid, succinic acid and citric acid.  
     
     
         18 . The reinforced composite article of  claim 14 , wherein said boron-containing compound is selected from at least one of boric acid, boron oxide, sodium tetraborate, potassium metaborate, potassium tetraborate, ammonium biborate, ammonium tetrafluoroborate, butylammonium tetrafluoroborate, calcium tetrafluoroborate, lithium fluoroborate, potassium tetrafluoroborate, sodium tetrafluoroborate, tetrabutylammonium tetrafluoroborate, tetraethylammonium tetrafluoroborate and zinc tetrafluoroborate.  
     
     
         19 . The reinforced composite article of  claim 14 , wherein said epoxy resin emulsion is present in said sizing composition in an amount of from about 60 to about 90% by weight solids, said aminosilane coupling agent is present in said sizing composition in an amount of from about 0.4 to about 0.8% by weight solids, said epoxy silane coupling agent is present in said sizing composition in an amount of from about 10 to about 20% by weight solids, said non-ionic lubricant is present in said sizing composition in an amount of from about 6 to about 10% by weight solids, said cationic lubricant and antistatic agent are present in said sizing composition in an amount of from about 0.4 to about 0.8% by weight solids, said at least one organic acid is present in said sizing composition in an amount of from about 0.4 to about 1.0% by weight solids and said boron-containing compound is present in an amount of from about 0.2 to about 3.0% by weight solids.  
     
     
         20 . The glass fiber of  claim 19 , wherein said glass fiber is selected from at least one of A-type glass, C-type glass, E-type glass, S-type glass, R-type glass, AR-type glass and E-CR-type glass.