Fiber size, sized reinforcements, and articles reinforced with such reinforcements

Abstract

The present invention relates to fiber-size compositions for coating glass or other reinforcing fiber materials that are used in the manufacturing of composites. The fiber-size composition contains at least about 4% by weight of a polyvinylpyrrolidone film former, at least one lubricant and a coupling agent. The sizing composition gives the fibers desirable properties such as high strength, improved flexibility, fuzz formation resistance, and fiber smoothness and softness.

1 . A fiber-size composition comprising: 
 at least about 4% by weight of a polyvinylpyrrolidone film former having a molecular weight in the range of about 10,000 to about 70,000;    at least one lubricant;    and a coupling agent.    
     
     
         2 . The fiber-size composition according to  claim 1  wherein said lubricant is polyethylene glycol.  
     
     
         3 . (canceled)  
     
     
         4 . The fiber-size composition of  claim 1  further comprising a polyethyleneimine polyamide salt lubricant  
     
     
         5 . The fiber-size composition of  claim 1  wherein said coupling agent is a silane coupling agent.  
     
     
         6 . A fiber-size composition comprising: at least about 4% by weight of a polyvinylpyrrolidone film former at least one lubricant: a coupling agent, and further comprising a polyurethane.  
     
     
         7 . A fiber-size composition comprising: 
 from about 1.0% to about 3.0 by weight of a silane coupling agent;    from about 4.0% to about 7.0% by weight of a polyvinylpyrrolidone film-former;    from about 1.0% to about 4.0% by weight of a polyurethane film-former,    from about 2.0% to about 3.5% by weight of a polyethylene glycol lubricant;    from about 0.45% to about 0.70% by weight of a polyethyleneimine polyamide salt lubricant;    from about 0.3% to about 0.6% by weight of an acetic acid; and    the remainder water, the sum of the fiber-size constituents making 100%.    
     
     
         8 . A reinforcing fiber coated with the fiber-size composition of  claim 1 .  
     
     
         9 . The reinforcing fiber of  claim 8  wherein said fiber is an E-glass fiber.  
     
     
         10 . A compounding formulation comprising the reinforcing fiber of  claim 8  and a matrix resin.  
     
     
         11 . The compounding formulation of  claim 10  wherein said matrix resin is selected from the group consisting of polyolefins, polyesters, polyacetals, polyamides, polyacrylamides, polyimides, polyethers, polyvinylethers, polystyrenes, polyoxides, polycarbonates, polysiloxanes, polysulfones, polyanhydrides, polyimines, epoxies, polyacrylics, polyvinylesters, polyurethane, maleic resins, urea resins, melamine resins, phenol resins, furan resins, polymer blends, polymer alloys, and mixtures thereof.  
     
     
         12 . The compounding formulation of  claim 10  wherein said matrix resin is a polyamide.  
     
     
         13 . A composite article formed from the compounding formulation of  claim 10 .  
     
     
         14 . A method of preparing reinforcing fibers comprising: 
 a) preparing a fiber-size composition comprising: 
 at least about 4% by weight of a polyvinylpyrrolidone film former having a molecular weight in the range of about 10,000 to about 70.000;  
 at least one lubricant; and  
 a coupling agent;  
   b) contacting fibers with said fiber-size composition; and    c) allowing said fiber-size composition to solidify on said fibers to form said reinforcing fibers.    
     
     
         15 . The method of preparing reinforcing fibers according to  claim 14  wherein said fibers are glass fibers.  
     
     
         16 . A method of preparing reinforcing fibers comprising: 
 a) preparing a fiber-size composition comprising: 
 at least about 4% by weight of a polyvinylpyrrolidone film former;  
 at least one lubricant; and  
 a coupling agent;  
   b) contacting fibers with said fiber-size composition; and    c) allowing said fiber-size composition to solidify on said fibers to form said reinforcing fibers; wherein said fiber-size composition further comprises a polyurethane film-former; and a second lubricant and acetic acid.    
     
     
         17 . The method of  claim 16  wherein said fiber-size composition comprises 
 from about 1.0% to about 3.0 by weight of a silane coupling agent;    from about 4.0% to about 7.0% by weight of a polyvinylpyrrolidone film-former;    from about 1.0% to about 4.0% by weight of a polyurethane film-former;    from about 2.1% to about 3.5% by weight of a polyethylene glycol lubricant;    from about 0.45% to about 0.70% by weight of a polyethyleneimine polyamide salt lubricant;    from about 0.3% to about 0.6% by weight of an acetic acid; and    the remainder water, the sum of the fiber-size constituents making 100%.    
     
     
         18 . The method of preparing reinforcing fibers according to  claim 15  wherein said glass fibers are essentially boron-free glass fibers.  
     
     
         19 . A method of preparing a composite formulation comprising the step of combining said reinforcing fibers prepared according to the method of  claim 14  with a matrix resin to form said composite formulation.  
     
     
         20 . A method of preparing a composite article comprising the step of forming said composite formulation formed in  claim 19  into said composite article.