Coating composition, method for coating a casting mold, use of the coating composition for coating a casting mold, and casting mold

Abstract

The present invention relates to a coating composition, comprising a solids component which comprises a first solid that is able to cleave CO2 in a temperature range from about 150 to about 1000° C., and that has a D50 value of at most about 10 pm. It is furthermore directed to a method for coating a casting mold, the use of the coating composition for coating a casting mold, and the coated casting mold.

1 . A coating composition, comprising:
 a solids component which comprises a first solid that is able to cleave CO 2  in a temperature range from about 150 to about 1000° C., and that has a D50 value of at most about 10 μm.   
     
     
         2 . The coating composition according to  claim 1 , wherein the first solid has a D99 value of at most about 30 μm and a D90 value of at most about 20 μm. 
     
     
         3 . The coating composition according to  claim 1 , wherein the first solid is selected from carbonates of the elements of the 2 nd , 7 th , 8 th , 9 th , 10 th , 11 th  and 12 th  groups of the periodic table of elements. 
     
     
         4 . The coating composition according to  claim 3 , wherein the first solid is selected from calcium carbonate, magnesium carbonate, dolomite or iron carbonate, or mixtures thereof. 
     
     
         5 . The coating composition according to  claim 1 , wherein the first solid is selected from starch. 
     
     
         6 . The coating composition according to  claim 1 , wherein the coating composition further comprises a carrier liquid. 
     
     
         7 . The coating composition according to  claim 6 , wherein the solubility product of the first component in the carrier liquid, in terms of K sp , at 25° C., is at least about 4. 
     
     
         8 . A method for coating a casting mold, wherein the method comprises the steps of:
 (a) providing a casting mold comprising a surface which defines a casting cavity,   (b) providing a coating composition according to  claim 1 ; and   (c) applying the coating composition to at least one part of the surface which defines the casting cavity.   
     
     
         9 . The method according to  claim 8 , wherein the coating composition further comprises a carrier liquid and the coating composition is dried after step (c). 
     
     
         10 . The method according to  claim 8 , wherein the coating penetrates at least 2 mm into the coated surface, and the layer thickness of the coating after drying the coating is at most about 100 μm. 
     
     
         11 - 12 . (canceled) 
     
     
         13 . A coated casting mold prepared by the method according to  claim 8 . 
     
     
         14 . The coating composition according to  claim 5 , wherein the first solid is selected from rice or oat starch. 
     
     
         15 . The coating composition according to  claim 6 , wherein the carrier liquid comprises water. 
     
     
         16 . The method according to  claim 8 , wherein the casting mold is equipped with one or more casting cores. 
     
     
         17 . A coated casting mold comprising a surface which defines a casting cavity having a coating layer on at least one part of the surface which defines the casting cavity, wherein the coating layer comprises a solids component which comprises a first solid that is able to cleave CO 2  in a temperature range from about 150 to about 1000° C., and that has a D50 value of at most about 10 μm. 
     
     
         18 . The coated casting mold of  claim 17 , wherein the casting mold is equipped with one or more casting cores. 
     
     
         19 . The coated casting mold of  claim 17 , wherein the coating penetrates at least 2 mm into the coated surface, and the layer thickness of the coating after drying the coating is at most about 100 μm. 
     
     
         20 . The coated casting mold of  claim 17 , wherein the first solid has a D99 value of at most about 30 μm and a D90 value of at most about 20 μm. 
     
     
         21 . The coated casting mold of  claim 17 , wherein the first solid is selected from carbonates of the elements of the 2 nd , 7 th , 8 th , 9 th , 10 th , 11 th  and 12 th  groups of the periodic table of elements. 
     
     
         22 . The coated casting mold of  claim 17 , wherein the first solid is selected from calcium carbonate, magnesium carbonate, dolomite or iron carbonate, or mixtures thereof.