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 surface and used to polish the surface. The defects within the surface are removed without the removal of significant amounts of the material. Accordingly, the present invention removes defects from surfaces without creating optical distortion.

1 . A composition for removing defects from 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 2.5% to about 8.5% 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 , further comprising a suspension agent having a constant viscosity. 
     
     
         6 . A method of removing defects from a plastic surface, comprising:
 applying a first composition to the plastic surface, the first composition comprising:
 from 35% to 55% by weight of an abrasive having a particle size of at least about 6 microns in diameter; 
 from 1.3% to 3.5% by weight of a thixotropic suspension agent; 
 from 0.4% to 1.9% by weight of a surfactant; and 
 from 0.3% to 2.5% by weight of a lubricant; 
   polishing the plastic surface;   applying in a second step a second composition to the plastic surface, the second composition comprising:
 from 15% to 27% by weight of an abrasive; 
 from 2.5% to 9% by weight of a thixotropic suspension agent; 
 from 1.5% to 5% by weight of a surfactant; and 
 from 2.5% to 8.5% by weight of a lubricant; and 
   polishing the plastic surface.   
     
     
         7 . The method of  claim 6 , wherein the first composition is applied to the plastic surface with a buffing pad. 
     
     
         8 . The method of  claim 7 , wherein the buffing pad comprises polyurethane. 
     
     
         9 . The method of  claim 7 , wherein the buffing pad comprises a semi-synthetic material. 
     
     
         10 . The method of  claim 9 , wherein the semi-synthetic material comprises rayon. 
     
     
         11 . The method of  claim 6 , wherein the second composition is applied to the plastic surface with a buffing pad. 
     
     
         12 . The method of  claim 11 , wherein the buffing pad comprises polyurethane. 
     
     
         13 . The method of  claim 11 , wherein the buffing pad comprises a semi-synthetic material. 
     
     
         14 . The method of  claim 13 , wherein the semi-synthetic material comprises rayon. 
     
     
         15 . The method of  claim 6 , wherein the first composition further comprises up to about 12% by weight of an organic solvent. 
     
     
         16 . The method of  claim 6 , wherein the second composition comprises up to about 22% by weight of an organic solvent. 
     
     
         17 . The method of  claim 6 , wherein each composition further comprises from about 0.01% to about 1% by weight of a pigment. 
     
     
         18 . The method of  claim 6 , wherein each composition further comprise not more than about 0.4% of a fungicide. 
     
     
         19 . The method of  claim 6 , wherein each composition further comprises from about 0.5% to about 15% of a suspension agent having a constant viscosity.