Abrasion resistant urethane coatings

Abstract

A radiation curable and abrasion resistant coating composition is provided comprising: (a) 70% to 98% by weight of an urethane-acrylate oligomer; (b) 2% to 30% of fine particles of a filler capable of imparting abrasion resistance having an average particle size in the range of 1-20 microns; (c) optionally a reactive diluent; and (d) optionally an synthetic resin. The coatings when applied to wood floorings impart superior abrasion resistance.

What is claimed is:  
     
         1 . A coating composition comprising: 
 (a) a synthetic resin; and    (b) fine particles of a filler blend capable of imparting abrasion resistance, said filler blend comprising a mixture of inorganic and organic particles wherein said inorganic particles have an average particle size in the range of 1-20 microns and wherein said organic particles have an average particle size in the range of 1-20 microns.    
     
     
         2 . The composition of    claim 1    further including a curing agent.  
     
     
         3 . The composition of    claim 1    wherein said synthetic resin is an (meth)acrylate terminated polyurethane.  
     
     
         4 . The composition of    claim 1    wherein said inorganic filler is selected from the group consisting of oxides of aluminum, magnesium and silicon, and said organic filler is selected from the group consisting of a synthetic resin and diamond particles.  
     
     
         5 . The composition of    claim 3    further including at least one member selected from the group consisting of acrylic resins, vinyl resins, melamine and acrylated melamine resins, polyester resins, alkyd resins, epoxy resins, cellulose resins, amino resins and silicone resins.  
     
     
         6 . The composition of    claim 2    wherein said curing agent is a peroxide.  
     
     
         7 . The composition of    claim 2    wherein said curing agent is a azo material.  
     
     
         8 . A radiation curable coating composition comprising: 
 (a) an oligomer of the formula                          wherein R 1  is hydrogen or methyl; and Y is a divalent urethane residue; and    (b) fine particles of a filler blend capable of imparting abrasion resistance, said filler blend comprising a mixture of inorganic and organic particles wherein said inorganic particles have an average particle size in the range of 1-20 microns and wherein said organic particles have an average particle size in the range of 1-20 microns.    
     
     
         9 . The coating composition of    claim 8   , further comprising a vinyl monomer selected from the group consisting of N-vinyl-2-pyrrolidone, multifunctional acrylic acid esters and mixtures thereof.  
     
     
         10 . The coating composition of    claim 8    further comprising an addition polymerization inhibitor present in an amount sufficient to avoid the auto-polymerization of the composition during storage.  
     
     
         11 . The composition of    claim 8    wherein said inorganic filler is selected from the group consisting of oxides of aluminum, magnesium and silicon, and said organic filler is a synthetic resin.  
     
     
         12 . The composition of    claim 11    wherein said filler is aluminum trihydrate having a particle size in the range of 3-5 microns.  
     
     
         13 . The composition of    claim 12    further including at least one member selected from the group consisting of acrylic resins, vinyl resins, melamine and acrylated melamine resins, polyester resins, alkyd resins, epoxy resins, cellulose resins, amino resins and silicone resins.  
     
     
         14 . A radiation curable coating composition comprising: 
 (a) 70% to 98% by weight of an oligomer of the formula                          wherein R 1  is hydrogen or methyl; and Y is a divalent urethane residue;    (b) 2% to 30% by weight of fine particles of a filler blend capable of imparting abrasion resistance, said filler blend comprising a mixture of inorganic and organic particles, wherein said inorganic particles have an average particle size in the range of 1-20 microns and wherein said organic particles have an average particle size in the range of 1-20 microns;    (c) optionally a reactive diluent; and    (d) optionally an synthetic resin.    
     
     
         15 . The radiation curable composition of    claim 14    wherein said urethane oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  hydrogen or methyl; R 2  is lower alkylene; R 3  is aliphatic or cycloaliphatic; X is —O—or —NH—; n is an integer from 2 to 50 inclusive.  
     
     
         16 . The radiation curable composition of    claim 14    wherein said urethane oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  hydrogen or methyl; R 2  is lower alkylene; R 3  is aliphatic or cycloaliphatic; X is —O—or —NH—; n is an integer from 2 to 50 inclusive.  
     
     
         17 . The radiation curable composition of    claim 15    wherein said urethane oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       R 1  is hydrogen or methyl.  
     
     
         18 . The radiation curable composition of    claim 16    wherein said urethane oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       R 1  is hydrogen or methyl.  
     
     
         19 . The radiation curable composition of    claim 14    wherein said reactive diluent is N-vinyl pyrrolidone.  
     
     
         20 . A cellulosic article coated with the composition of    claim 1   .  
     
     
         21 . A wood article coated with the composition of    claim 1   .  
     
     
         22 . A cellulosic article coated with the composition of    claim 8   .  
     
     
         23 . A wood article coated with the composition of    claim 8   .  
     
     
         24 . A cellulosic article coated with the composition of    claim 14   .  
     
     
         25 . A wood article coated with the composition of    claim 14   .  
     
     
         26 . A method of imparting abrasion resistance to wood floorings, which method comprises applying to said floorings a radiation curable coating composition comprising: 
 (a) 70% to 98% by weight of an oligomer of the formula                          wherein R 1  is hydrogen or methyl; and Y is a divalent urethane residue;    (b) 2% to 30% by weight of fine particles of a filler blend capable of imparting abrasion resistance, said filler blend comprising a mixture of inorganic and organic particles, wherein said inorganic particles have an average particle size in the range of 1-20 microns and wherein said organic particles have an average particle size in the range of 1-20 microns;    (c) optionally a reactive diluent; and    (d) optionally an synthetic resin.    
     
     
         27 . The method of    claim 26    wherein said UV curable oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  hydrogen or methyl; R 2  is lower alkylene; R 3  is aliphatic or cycloaliphatic; X is —O—or —NH—; n is an integer from 2 to 50 inclusive.  
     
     
         28 . The method of    claim 26    wherein said UV curable oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  is hydrogen or methyl; R 2  is lower alkylene; R 3  is aliphatic or cycloaliphatic; X is —O—or —NH—; n is an integer from 2 to 50 inclusive.  
     
     
         29 . The method of    claim 28    wherein said oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       wherein R 1  is hydrogen or methyl.  
     
     
         30 . The method of    claim 28    wherein said oligomer has the formula:  
       
         
           
           
               
               
           
         
       
       R 1  is hydrogen or methyl.  
     
     
         31 . The method of    claim 26    wherein said reactive diluent is N-vinyl-pyrrolidone.  
     
     
         32 . An article obtained by ultraviolet curing of an article according to    claim 25   .