Process for preparing foundry shapes

Abstract

This invention relates to a process for preparing foundry shapes, e.g. cores and molds. The process comprises forming a foundry mix comprising (1) a major amount of foundry aggregate, (2) an acid-curable foundry resin, and (3) an acid catalyst, shaping the foundry mix into a foundry shape, and partially or totally removing water from the foundry shape.

1 . A process for preparing a foundry shape comprising: 
 A. preparing a foundry mix comprising a major amount of foundry aggregate, an effective binding amount of an acid-curable resin, and a catalytically effective amount of an acid catalyst;    B. shaping the foundry mix into a foundry shape; and    C. partially or totally removing water from the foundry shape.    
     
     
         2 . The process of  claim 1  wherein the acid-curable resin is selected from the group consisting of furan resins and phenolic resins.  
     
     
         3 . The process of  claim 2  wherein the acid catalyst is selected from the group consisting of sulfonic acid, toluene sulfonic acid, benzene sulfonic acid, and mixtures thereof.  
     
     
         4 . The process of  claim 3  wherein the foundry mix further comprises a silane.  
     
     
         5 . The process of  claim 4  wherein the resin is a furan resin containing unreacted furfuryl alcohol in the amount of about 50 to about 95 weight percent, wherein said weight percent is based upon the weight of the furan resin.  
     
     
         6 . The process of  claim 4  wherein the resin is a phenolic resole resin containing unreacted phenol in the amount of about 12 to about 16 weight percent, wherein said weight percent is based upon the weight of the phenolic resole resin.  
     
     
         7 . The process of  claim 5  wherein the foundry mix comprises: (a) at least 93 weight percent aggregate, and (b) from about 1 weight percent to about 5 weight percent furan resin, where said weight percents are based upon the weight of the foundry mix.  
     
     
         8 . The process of  claim 7  wherein the amount of acid catalyst is from about 10 to to about 50 weight percent, based upon the weight of the furan resin.  
     
     
         9 . The process of  claim 5  wherein the foundry mix comprises: (a) at least 0.93 weight percent aggregate, and (b) from about 1 weight percent to about 5 weight percent phenolic resin where said weight percents are based upon the weight of the foundry mix.  
     
     
         10 . The process of  claim 9  wherein the amount of acid catalyst is from about 10 to about 50 weight percent, based upon the weight of the phenolic resin.  
     
     
         11 . The process of claims  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 , or  10  wherein foundry shape is subjected to heat while water is being removed from the foundry shape.  
     
     
         12 . The process of  claim 11  wherein the heat is applied by blowing air and/or an inert gas having a temperature of less than 100° C. over and/or around the foundry shape.  
     
     
         12 . The process of claims  1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 , or  10  wherein the water is removed by pulling air and/or an inert gas around and/or through the foundry shape.  
     
     
         13 . The process of claims  12  wherein foundry shape is subjected to heat while water is being removed from the foundry shape.  
     
     
         14 . The process of  claim 13  wherein the heat is applied by blowing air and/or an inert gas having a temperature of less than 100° C. over and/or around the foundry shape.  
     
     
         15 . A process for preparing a foundry shape comprising: 
 A. preparing a foundry mix comprising a major amount of foundry aggregate, an effective binding amount of an acid-curable resin, and a catalytically effective amount of an acid catalyst;    B. shaping the foundry mix into a foundry shape; and    C. partially or totally removing water from the foundry shape by pushing air and/or an inert gas around and/or through the foundry shape.    
     
     
         16 . The process of  claim 15  wherein the acid-curable resin is selected from the group consisting of furan resins and phenolic resins.  
     
     
         17 . The process of  claim 16  wherein the acid catalyst is selected from the group consisting of sulfonic acid, toluene sulfonic acid, benzene sulfonic acid, and mixtures thereof.  
     
     
         18 . The process of  claim 17  wherein the foundry mix further comprises a silane.  
     
     
         19 . The process of  claim 18  wherein the resin is a furan resin containing unreacted furfuryl alcohol in the amount of about 50 to about 95 weight percent.  
     
     
         20 . The process of  claim 19  wherein the resin is a phenolic resole resin containing unreacted phenol in the amount of about 12 to about 16 weight percent.  
     
     
         21 . The process of  claim 20  wherein the foundry mix comprises: (a) at least 93 weight percent aggregate, and (b) from about 1 weight percent to about 5 weight percent furan resin, where said weight percents are based upon the weight of the foundry mix.  
     
     
         22 . The process of  claim 21  wherein the amount of acid catalyst is from about 10 to to about 50 weight percent, based upon the weight of the furan resin.  
     
     
         23 . The process of  claim 22  wherein the foundry mix comprises: (a) at least 93 weight percent aggregate, and (b) from about 1 weight percent to about 5 weight percent phenolic resin where said weight percents are based upon the weight of the foundry mix.  
     
     
         24 . The process of  claim 23  wherein the amount of acid catalyst is from about 10 to about 50 weight percent, based upon the weight of the phenolic resin.  
     
     
         25 . The process of claims  15 ,  16 ,  17 ,  18 ,  19 ,  20 ,  21 ,  22 ,  23 , or  24  wherein foundry shape is subjected to heat while water is being removed from the foundry shape.  
     
     
         26 . The process of  claim 25  wherein the heat is applied by blowing air and/or an inert gas having a temperature of less than 100° C. over and/or around the foundry shape.  
     
     
         27 . A process for preparing a foundry shape comprising: 
 A. preparing a foundry mix comprising a major amount of foundry aggregate, an effective binding amount of an acid-curable resin, and a catalytically effective amount of an acid catalyst;    B. shaping the foundry mix into a foundry shape; and    C. partially or totally removing water from the foundry shape by subjecting the foundry shape to a vacuum.    
     
     
         28 . The process of  claim 27  wherein the acid-curable resin is selected from the group consisting of furan resins and phenolic resins.  
     
     
         29 . The process of  claim 28  wherein the acid catalyst is selected from the group consisting of sulfonic acid, toluene sulfonic acid, benzene sulfonic acid, and mixtures thereof.  
     
     
         30 . The process of  claim 29  wherein the foundry mix further comprises a silane.  
     
     
         31 . The process of  claim 30  wherein the resin is a furan resin containing unreacted furfuryl alcohol in the amount of about 50 to about 95 weight percent.  
     
     
         32 . The process of  claim 31  wherein the resin is a phenolic resole resin containing unreacted phenol in the amount of about 12 to about 16 weight percent.  
     
     
         33 . The process of  claim 32  wherein the foundry mix comprises: (a) at least 93 weight percent aggregate, and (b) from about 1 weight percent to about 5 weight percent furan resin, where said weight percents are based upon the weight of the foundry mix.  
     
     
         34 . The process of  claim 33  wherein the amount of acid catalyst is from about 10 to about 50 weight percent, based upon the weight of the furan resin.  
     
     
         35 . The process of  claim 34  wherein the foundry mix comprises: (a) at least 93 weight percent aggregate, and (b) from about 1 weight percent to about 5 weight percent phenolic resin where said weight percents are based upon the weight of the foundry mix.  
     
     
         36 . The process of  claim 35  wherein the amount of acid catalyst is from about 10 to about 50 weight percent, based upon the weight of the phenolic resin.  
     
     
         37 . The process of claims  27 ,  28 ,  29 ,  30 ,  31 ,  32 ,  33 ,  34 ,  35 , or  36  wherein foundry shape is subjected to heat while water is being removed from the foundry shape.  
     
     
         38 . The process of  claim 37  wherein the heat is applied by blowing air and/or an inert gas having a temperature of less than 100° C. over and/or around the foundry shape.