Compositions and methods for removing scratches from plastic surfaces

Abstract

A composition including an abrasive, a suspension agent, a surfactant, and a lubricant, is provided for removing scratches, hazing, discoloration, and other defects from plastic surfaces. The composition is applied to a plastic surface and used to polish the surface. The defects within the surface of the plastic are removed without the removal of significant amounts of the plastic material. Accordingly, the present invention removes defects from plastic surfaces without creating optical distortion.

1 . A composition for removing defects from plastic surfaces, comprising: 
 from about 15% to about 27% by weight of an abrasive;    from about 2.5% to about 9% by weight of a thixotropic suspension agent;    from about 1.5% to about 5% by weight of a surfactant; and    from about 0.3% to about 2.5% by weight of a lubricant.    
   
   
       2 . The composition of  claim 1 , further comprising up to about 22% by weight of an organic solvent.  
   
   
       3 . The composition of  claim 1 , further comprising from about 0.01% to about 1% by weight of a pigment.  
   
   
       4 . The composition of  claim 1 , further comprising a fungicide.  
   
   
       5 . The composition of  claim 1 , wherein the abrasive is formed of particles having a diameter no greater than about 18 microns.  
   
   
       6 . The composition of  claim 1 , further comprising a suspension agent having a constant viscosity.  
   
   
       7 . A composition for removing defects from plastic surfaces, comprising: 
 from about 35% to about 55% by weight of an abrasive;    from about 1.3% to about 3.5% by weight of a thixotropic suspension agent; and    from about 0.4% to about 1.9% by weight of a surfactant; and    from about 0.3% to about 2.5% by weight of a lubricant.    
   
   
       8 . The composition of  claim 7 , further comprising up to about 12% by weight of an organic solvent.  
   
   
       9 . The composition of  claim 7 , further comprising from about 0.01% to about 1% by weight of a pigment.  
   
   
       10 . The composition of  claim 7 , further comprising a fungicide.  
   
   
       11 . The composition of  claim 7 , wherein the abrasive is formed of particles having a diameter greater than about 6 microns.  
   
   
       12 . The composition of  claim 7 , further comprising a suspension agent having a constant viscosity.  
   
   
       13 . A method of removing defects from a plastic surface, comprising: 
 applying a first composition to the plastic surface, the first composition, comprising: 
 from about 35% to about 55% by weight of an abrasive having a particle size of at least about 6 microns in diameter;  
 from about 1.3% to about 3.5% by weight of a thixotropic suspension agent; and  
 from about 0.4% to about 1.9% by weight of a surfactant; and  
 from about 0.3% to about 2.5% by weight of a lubricant;  
   polishing the plastic surface;    applying a second composition to the plastic surface, the second composition comprising: 
 from about 15% to about 27% by weight of an abrasive having a particle size of no more than about 18 microns in diameter;  
 from about 2.5% to about 9% by weight of a thixotropic suspension agent;  
 from about 1.5% to about 5% by weight of a surfactant; and  
 from about 0.3% to about 2.5% by weight of a lubricant; and  
   polishing the plastic surface.    
   
   
       14 . The method of  claim 13 , wherein the first composition further comprises up to about 22% by weight of an organic solvent.  
   
   
       15 . The method of  claim 13 , wherein the second composition further comprises up to about 12% by weight of an organic solvent.  
   
   
       16 . The method of  claim 13 , wherein each composition further comprises from about 0.01% to about 1% by weight of a pigment.  
   
   
       17 . The method of  claim 13 , wherein each composition further comprises a fungicide.  
   
   
       18 . The method of  claim 13 , wherein each composition further comprises a suspension agent having a constant viscosity.  
   
   
       19 . The method of  claim 13 , wherein applying comprises applying by hand with a reciprocating motion.  
   
   
       20 . The method of  claim 13 , wherein polishing comprises polishing with an open cell polyester material.  
   
   
       21 . The method of  claim 13 , further comprising removing a residual composition with a cloth having an antistatic compound.