Anti-stick coating for surfaces

Abstract

A release agent composition to prevent sticking and facilitate separation of surfaces, such as patterns and core boxes from foundry molds and core s comprises (a) a cross-linkable fluorotelomer comprising repeat units derived from a fluoroalkene; (b) a moisture-curable silicone; (c) a catalyst; and (d) a solvent. Further is provided a method to improve the release properties of molds removed from a pattern or core box comprising applying the release agent composition to the pattern or core box surface.

1 . A release agent composition comprising (a) a crosslinkable fluorotelomer comprising repeat units derived from a fluoroalkene; (b) a moisture-curable silicone; (c) a catalyst; and (d) a solvent.  
   
   
       2 . The composition of  claim 1  wherein a majority of the end groups. of the fluorotelomer are derived from a secondary alcohol or derivative thereof.  
   
   
       3 . The composition of  claim 2  wherein the fluoroalkene contains 2 to about 10 carbon atoms.  
   
   
       4 . The composition of  claim 3  wherein the fluoroalkene contains 2 to 3 carbon atoms.  
   
   
       5 . The composition of  claim 4  wherein the secondary alcohol has 4 to about 12 carbon atoms and an α-hydrogen.  
   
   
       6 . The composition of  claim 5  wherein the secondary alcohol is 2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-butylacetate, cyclohexanol, 1-methoxy-2-propanol, 1-methoxy-3-butanol, 1-methoxy-2-pentanol, 1-methoxy-2-propanol acetate ester, or combinations of two or more thereof.  
   
   
       7 . The composition of  claim 1  wherein the moisture-curable silicone has terminal alkoxy, carboxy, or amino groups.  
   
   
       8 . The composition of  claim 7  wherein the moisture-curable silicone is a polyorganosiloxane.  
   
   
       9 . The composition of  claim 8  wherein the polyorganosiloxane is a methoxy-terminated siloxane selected from polydimethylsiloxane, polymethylhydrogensiloxane, polysilsesquioxane, polytrimethylsiloxane, polydimethylcyclosiloxane, or combination of two or more thereof.  
   
   
       10 . The composition of  claim 1  wherein the catalyst has the formula M(OR 2 ) 4  where M is zirconium or titanium and each R 2  is alkyl, cycloalkyl, alkaryl, or hydrocarbon radical containing from about 1 to about 30 carbon atoms per radical.  
   
   
       11 . The composition of  claim 1  wherein the catalyst is zirconium acetate, zirconium propionate, zirconium butyrate, zirconium hexanoate, zirconium 2-ethyl hexanoate, zirconium octanoate, tetraethyl zirconate, tetrapropyl zirconate, tetraisopropyl zirconate, tetrabutyl zirconate, titanium acetate, titanium propionate, titanium butyrate, titanium hexanoate, titanium 2-ethyl hexanoate, titanium octanoate, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, or combination of two or more thereof.  
   
   
       12 . The composition of  claim 11  wherein the catalyst is tetraisopropyl titanate, tetrabutyl titanate, or a combination thereof.  
   
   
       13 . The composition of  claim 1  wherein the solvent is aromatic hydrocarbon, alkane, alcohol, ketone, ester, ether, inorganic solvent, water, and combinations of two or more thereof such as, for example, xylene, benzene, toluene, n-heptane, octane, cyclohexane, dodecane, methanol, ethanol, isopropyl alcohol, acetone, methyl ethyl ketone, dipropylene glycol, dipropylene glycol methyl ether, methylene chloride, methylene dichloride, ethylene dichloride, carbon tetrachloride, chloroform, perchloroethylene, ethyl acetate, tetrahydrofuran, dioxane, white spirit, mineral spirits, naphtha, or combination of two or more thereof.  
   
   
       14 . The composition of  claim 1  further comprising a silicone intermediate.  
   
   
       15 . The composition of  claim 14  wherein the silicone intermediate is hydroxy-terminated polyorganosiloxane.  
   
   
       16 . The composition of  claim 15  wherein the silicone intermediate comprises a volatile siloxane.  
   
   
       17 . A method to ease separation of a workpiece from a substrate comprising applying the release agent composition of  claim 1  to a surface of the workpiece, the substrate, or both.  
   
   
       18 . A method for improving the release properties of molds removed from a pattern or cores from a core box comprising applying a composition comprising (a) a crosslinkable fluorotelomer comprising repeat units derived from a fluoroalkene; (b) a moisture-curable silicone; (c) a catalyst; and (d) a solvent to a surface of a pattern or core box.  
   
   
       19 . The method of  claim 18  wherein a majority of the end groups of the fluorotelomer are derived from a secondary alcohol or derivative thereof.  
   
   
       20 . The method of  claim 19  wherein the catalyst has the formula M(OR 2 ) 4  where M is zirconium or titanium and each R 2  is alkyl, cycloalkyl, alkaryl, or hydrocarbon radical containing from about 1 to about 30 carbon atoms per radical.  
   
   
       21 . The method of  claim 20  wherein the release agent composition further comprises a silicone intermediate.  
   
   
       22 . A method to prevent squeaking of rubber weatherstripping comprising applying the release agent composition of  claim 1  to a surface of weatherstripping.  
   
   
       23 . A method to protect surfaces from foreign matter comprising applying the release agent composition of  claim 1  to a surface of a substrate.  
   
   
       24 . The method of  claim 23  wherein the substrate is wood, metal, plastic, rubber, stone, cement, concrete, glass, fiber, tile, or combination of two or more thereof.  
   
   
       25 . A method to reduce formation of rust on a steel surface comprising applying the release agent composition of  claim 1  to a steel surface.