Scratch resistant coating composition with a combination of hard particles

Abstract

An abrasion resistant flooring covering formed from a UV curable coating composition having binder and diamond particles—the abrasion resistant flooring covering used to overcoat the surface of flooring products or various abrasion heavy surfaces to protect such a products or surfaces from damage by abrasion or scratch.

1 . A floor covering comprising
 a substrate, and   a coating layer comprising:
 a coating matrix formed from a curable coating composition comprising a binder, 
 wherein the coating matrix has an average coating matrix thickness; and 
 an abrasion resistant particle comprising:
 a mixture of first abrasion resistant particles and second abrasion particles, 
 the first abrasion resistant particles having an average primary particle size and a narrow distribution of primary particle sizes, the narrow distribution of primary particle sizes having a standard deviation less than 35% of the primary average particle size; and 
 
   wherein the first abrasion resistant particles are diamond particle and the second abrasion resistant particles are particles other than diamond particles and have a Mohs hardness value of at least 6 and the second abrasion resistant particles are present relative to the first abrasion resistant particles in a weight ratio ranging from 1:1 to 8:1.   
     
     
         2 . The floor covering of  claim 1  wherein the coating layer comprises less than 12 wt. % of abrasion resistant particles based on the weight of the coating layer. 
     
     
         3 . The floor covering of  claim 2  wherein the coating layer comprises at least 6 wt. % of the abrasion resistant particles based on the weight of the coating layer. 
     
     
         4 . The floor covering of  claim 1  wherein the average coating matrix thickness ranges from about 4 μm to about 40 μm. 
     
     
         5 . The floor covering of  claim 4  wherein the average coating matrix thickness ranges from about 6 μm to about 20 μm. 
     
     
         5 . The floor covering of  claim 1  wherein the second abrasion resistant particles are aluminum oxide and the weight ratio ranges from about 1:1 to about 4:1. 
     
     
         6 . The floor covering of  claim 5  wherein the abrasion resistant particles are present in the coating layer by an amount ranging from about 6 wt. % to about 10 wt. %. 
     
     
         7 . The floor covering of  claim 1  wherein the average coating matrix thickness is measured from a top surface of the coating matrix to a bottom surface of the coating matrix and the abrasion resistant particles protrude from the top surface of the coating matrix at a distance ranging from about 1% to about 50% of the coating matrix thickness. 
     
     
         8 . The floor covering of  claim 1  wherein the average coating matrix thickness is measured from a top surface of the coating matrix to a bottom surface of the coating matrix and the abrasion resistant particles are submerged beneath the top surface of the coating matrix at a distance that is about 1% to about 50% of the coating matrix thickness. 
     
     
         9 . The floor covering of  claim 1  wherein the average coating matrix thickness is measured from a top surface of the coating matrix to a bottom surface of the coating matrix and the abrasion resistant particles are submerged beneath the top surface of the coating matrix at a first distance that is about 1% to about 25% of the coating matrix thickness and the abrasion resistant particles are vertically offset from the bottom surface of the coating matrix by a second distance that is about 1% to about 25% of the coating matrix thickness. 
     
     
         10 . The floor covering of  claim 1  wherein the coating matrix thickness to the first particle size form a ratio ranges from 0.6:1 to 2:1. 
     
     
         11 . A floor covering comprising
 a substrate, and   a coating layer comprising
 a coating matrix formed from a curable coating composition comprising a binder, 
 the coating matrix comprising an average coating matrix thickness: and 
 abrasion resistant particles comprising:
 first abrasion resistant particles having an average particle size ranging from 2 μm to 50 μm, and 
 second abrasion resistant particles that have a Mohs hardness value of at least 6; 
 
   wherein the first abrasion resistant particles are diamond particles and the second abrasion resistant particles are particles other than diamond, and wherein an average distance between two adjacently placed first abrasion resistant particles ranges of from 20 μm to 75 μm.   
     
     
         12 . The floor covering of  claim 11  wherein the coating layer comprises 6 wt. % to 12 wt. % of abrasion resistant particles based on the weight of the coating layer. 
     
     
         13 . The floor covering of  claim 11  wherein the a ratio of the average coating matrix thickness to the average particle size ranges from about 0.6:1 to about 2:1. 
     
     
         14 . The floor covering of  claim 11  wherein the average coating matrix thickness ranges from 4 μm to 40 μm. 
     
     
         15 . The floor covering of  claim 14  wherein the average coating matrix thickness ranges from 6 μm to 20 μm. 
     
     
         116 . The floor covering of  claim 11  wherein the second abrasion resistant particles are aluminum oxide. 
     
     
         17 . The floor covering of  claim 11  wherein the second abrasion resistant particles are feldspar. 
     
     
         18 . A method of forming a multi-layer floor covering comprising:
 a) Providing a first coating composition comprising a first curable binder and a first curing initiator and a second coating composition comprising a second curable binder and a second curing initiator   b) applying a first layer of the first coating composition on a substrate, the first layer applied such that the first coating composition exhibits a first average coating thickness as measured from a top surface and a bottom surface of the first layer;   c) partially or fully curing the first coating composition;   d) applying a second layer of the second coating composition on the top surface of the first layer, the second layer applied such that the second coating composition exhibits a second average coating thickness as measured from a top surface and a bottom surface of the second layer;   e) partially or fully curing the second coating composition;
 wherein at least one of the first and the second coating compositions comprise abrasion resistant particles that include diamond particles and second abrasion resistant particle having a Mohs hardness value of at least 6, the diamond particle having an average particle size and being present relative to the second abrasion resistant particles are particles other than diamond particles, wherein the first abrasion resistant particles and the second abrasion resistant particles are in a weight ratio ranging from about 1:1 to about 1:8; 
 wherein for each of the first and second coating compositions that contain the abrasion resistant particles, a ratio for each of the first average coating thickness and the second average coating thickness to the average particle size of the diamond particle ranges from 0.6:1 to 2:1; and 
 wherein for each of the first and the second coating compositions that contain the abrasion resistant particles, the curing of the first and the second coating compositions results in the diamond particle being vertically offset from at least one of the respective bottom surfaces of the first and the second coating compositions by a length greater than zero.