Paint comprising a liquid phase and an active powder phase

Abstract

Coating composition comprising a liquid first phase comprising one or more polymer binder components having functional groups capable of cross-linking by electron pair exchange, and a second phase which is a powder material, such as sand, comprising one or more compounds capable of activating crosslinking of the binder components in the liquid phase after the second phase is exposed to the first phase. The activating compound in the second phase may include a Lewis acid or Lewis base. Method of applying a coating composition curable by cross-linking chemistry based on electron pair exchange, wherein after application of a layer of the coating composition on a substrate, a powder material comprising one or more cross-linking activating compounds is sprinkled over the wet layer. After sprinkling the powder material over the coating layer, a second coating layer is applied.

1 . Coating composition comprising one or more polymer binders cross-linkable by polar reaction and at least one catalyst, the cross-linkable polymer binders being comprised in a liquid phase, characterised in that a separate dry sprinkleable powder phase comprises at least a part of the catalyst and/or of a precursor of the catalyst which forms the catalyst in reaction with a co-reactive compound in the liquid phase 
     
     
         2 . A coating composition according to  claim 1 , characterised in that at least one catalyst includes a Lewis acid or Lewis base. 
     
     
         3 . A coating composition according to  claim 1 , characterised in that the liquid phase comprises a compound which is reactive with a precursor in the powder phase to form a Lewis base or Lewis acid after the liquid phase is exposed to the powder phase. 
     
     
         4 . A coating composition according to  claim 1 , characterised in that the liquid phase is a two-component composition, the first component comprising one or more polyisocyanates and the second component comprising a polythiol, polyol, polyamine or mixtures thereof. 
     
     
         5 . A coating composition according to  claim 1 , characterised in that the liquid phase is a two-component composition, the first component comprising one or more polyepoxies and the second component comprising one or more polythiols. 
     
     
         6 . A coating composition according to  claim 1 , characterised in that the liquid phase is a two-component composition, the first component comprising a polyunsaturated binder and at least one electron-withdrawing group linked to a carbon atom of at least one of the unsaturated bonds, the second component comprising a polythiol and/or a compound comprising acidic CH groups. 
     
     
         7 . A coating composition according to  claim 3 , characterised in that the powder phase comprises one or more phosphine compounds and in that the liquid phase comprises one or more electron-deficient olefins. 
     
     
         8 . A coating composition according to  claim 1 , characterised in that the powder phase comprises one or more amines. 
     
     
         9 . A coating composition according to  claim 1 , characterised in that the catalyst in the powder phase is a solid material in powder form. 
     
     
         10 . A coating composition according to  claim 9 , characterised in that the powder is zinc oxide, calcium oxide and/or calcium carbonate. 
     
     
         11 . A coating composition according to  claim 1 , characterised in that the powder comprises a solid carrier material in powder form having one or more of the activating compounds adsorbed to its surface. 
     
     
         12 . A coating composition according to  claim 11 , characterised in that the carrier material is sand, diatomaceous earth, zeolite, vitreous beads, barium sulphate, chalk, pigment, or mixtures thereof. 
     
     
         13 . A coating composition according to  claim 12 , characterised in that the powder material is titanium dioxide coated with a zirconium compound. 
     
     
         14 . A coating composition according to  claim 12 , characterised in that the carrier material comprises a mixture of sand having an average particle size above 200 micrometers and a fine sand having an average particle size below 100 micrometers. 
     
     
         15 . A coating composition according to  claim 14 , characterised in that it comprises more than about 60 wt. % of sand having an average particle size between 300-800 micrometers, 15-30 wt. % of quartz sand having an average particle size of 20-90 micrometers, and a fine grade quartz sand having an average particle size below 10 micrometers, preferably about 3 micrometers. 
     
     
         16 . A coating composition according to  claim 1 , characterised in that the powder phase comprises up to about 8 wt. % of the catalyst, preferably up to about 5 wt. %, more preferably up to about 3 wt. %. 
     
     
         17 . Method of applying a coating composition comprising in a liquid phase one or more polymer binders cross-linkable by polar reaction and in a separate dry powder phase at least one catalyst wherein after application of one or more layers of the liquid phase on a substrate, the powder phase is sprinkled over the wet liquid phase layer. 
     
     
         18 . Method of applying a coating composition comprising in a liquid phase one or more polymer binders cross-linkable by polar reaction and in a separate dry powder phase at least one precursor of a catalyst which forms the catalyst in reaction with a co-reactive compound in the liquid phase wherein after application of a layer of the liquid phase on a substrate, the powder phase is sprinkled over the wet liquid phase layer. 
     
     
         19 . Method according to  claim 17 , characterised in that the thickness of the freshly applied layer of liquid phase is less than the particle size of at least a part of the powder phase material, and in that after sprinkling the powder phase over the wet liquid phase layer, a second layer of the liquid phase is applied.