Adduct and thermosetting surfacing film and method of forming the same

Abstract

In various embodiments, the invention provides an in-situ adduct formed by reacting liquid, solid, and/or semi-solid epoxy resins with a di-carboxylic acid functionalized polymer. The adducting process at least doubles the viscosity of the mixture. A hot melt thermosetting surfacing film and composite formed using the adduct are also disclosed. Methods of preparing and using are also disclosed.

1 . A resin composition for forming a thermosetting surfacing film, the composition comprising:
 a resin component comprising one or more epoxy resins selected from a liquid resin, a solid resin, a semi-solid resin and a combination thereof;   from about 1% to about 20% (by weight of the total composition) of a carboxylic acid functionalized polymer having an average functionality of about 2 or more carboxylic acids prior to reacting said polymer with said resin component;   from about 20% to about 60% (by weight of the total composition), with or without an organic surface treatment, of a filler material, comprising 2 or more fillers and/or pigments selected from silica, aluminum hydroxide, aluminum trihydrate, carbon black, titanium dioxide, calcium carbonate and a combination thereof,   said resin composition having a viscosity of less than about 100 Pa·s at 71° C., and being free of solvent.   
     
     
         2 . The composition of  claim 1 , wherein the one or more epoxy resins comprises:
 (A) from about 5% to about 60% (by weight of the total composition) of a resin fraction selected from a low viscosity liquid epoxy resin, and a combination of said low viscosity liquid epoxy resin with one or more resin selected from a solid resin, and a semi-solid;   (B) from about 2% to about 40% (by weight of the total composition) of one or more solid bis-phenol A based epoxy resins having a softening point range from about 50° C. to about 130° C.; and   (C) from about 1% to about 30% (by weight of the total composition) of solid epoxy phenol novolac or epoxy cresol novolac having a functionality of about 2.2 or more.   
     
     
         3 . The composition of  claim 1 , further comprising:
 (D) from about 0.001% to about 5% (by weight of the total composition) of a defoamer and/or air release agent.   
     
     
         4 . (canceled) 
     
     
         5 . The composition of  claim 1 , further comprising:
 (F) from about 2% to about 10% (by weight of the total composition) of a curing agent.   
     
     
         6 . The composition of  claim 1 , further comprising:
 (G) from about 0.5% to about 5% (by weight of the total composition) of an accelerator or catalyst selected from a urea, a substituted urea, an imidazole, a substituted imidazole, a tertiary amine and a combination thereof.   
     
     
         7 . A solvent-free surfacing resin composition which is prepared by:
 (A) reacting,
 (1) from about 5% to about 60% (by weight of the total composition) of a resin fraction selected from a low viscosity liquid epoxy resin and a combination of said low viscosity liquid epoxy resin with one or more resin selected from a solid resin, and a semi-solid resin; 
 (2) from about 2% to about 40% (by weight of the total composition) of one or more solid bis-phenol A based epoxy resins having a softening point range from about 50° C. to about 130° C.; 
 (3) from about 1% to about 30% (by weight of the total composition) of solid epoxy phenol novolac or epoxy cresol novolac having an average functionality of about 2 or more; and 
 (4) from about 1% to about 20% (by weight of the total composition) of a carboxylic acid functionalized polymer; 
 thereby forming an adduct; and 
   (B) mixing with said adduct,
 (1) from about 0.001% to about 5% (by weight of the total composition) of a defoamer and/or air release agent; and 
 (2) from about 20% to about 60% (by weight of the total composition), with or without an organic surface treatment, of a filler material comprising 2 or 3 fillers and/or pigments, the filler material:
 (i) selected from silica, aluminum hydroxide, alumina, carbon black, titanium dioxide, calcium carbonate and a combination thereof; and 
 (ii) having an average particle size from about 5 nm to about 100 microns; 
 
 (3) from about 2% to about 10% (by weight of the total composition) of a curing agent; and 
 (4) from about 0.5% to about 5% (by weight of the total composition) of an accelerator or catalyst selected from a urea, a substituted urea, an imidazole, a substituted imidazole, a tertiary amine and a combination thereof, 
 thereby forming said resin composition. 
   
     
     
         8 . A solvent-free film product formed from the surfacing resin composition of  claim 7 , said product formed by a method comprising:
 (i) applying or coating the surfacing resin to a carrier to form a film product; and   (ii) after the applying, cooling the film product.   
     
     
         9 . The solvent-free surfacing resin composition of  claim 7 , wherein the carboxylic acid functionalized polymer has an average functionality of equal to or greater than about 2. 
     
     
         10 . The solvent-free surfacing resin composition of  claim 7 , wherein the carboxylic acid functionalized polymer is a di-carboxylic acid functionalized polymer. 
     
     
         11 . The solvent-free surfacing resin composition of  claim 7 , wherein the composition has a viscosity from about 20 Pa·s to about 100 Pa·s. 
     
     
         12 . A solvent-free resin composition for forming a thermosetting surfacing film, the composition comprising:
 a plurality of liquid, solid, and/or semi-solid epoxy resins; and   from about 1% to about 20% (by weight of the total composition) of a carboxylic acid functionalized polymer having an average functionality of equal to or greater than about 2; and from about 2% to about 70% of one or more filler, of which about 3% to about 10% is fumed silica, wherein is thixotropic.   
     
     
         13 . The resin composition according to  claim 1 , wherein the 2 fillers have a bimodal size distribution with a first population of filler particles and a second population of filler particles, wherein the particles of said first population are larger than the particles of said second population. 
     
     
         14 . The resin composition according to  claim 13 , wherein the mean particle size of said particles of said second population is from about 5 nanometers to about 60 nanometers. 
     
     
         15 . The resin composition according to  claim 1 , comprising a filler which is fumed silica with a mean particle size of about 12 microns. 
     
     
         16 . The resin composition according to  claim 1 , comprising a filler which is fumed silica with a specific surface area of from about 175 m 2 /g to about 225 m 2 /g. 
     
     
         17 . The resin composition according to  claim 1 , comprising a filler which has a D 90  particle size of less than about 10 microns. 
     
     
         18 . The resin composition according to  claim 1 , comprising filler particles with a mean primary particle size of from about 10 nm to about 50 nm, which is present in said composition in an amount of from about 1% to about 10%. 
     
     
         19 . (canceled)