Bio-based binder system

Abstract

A bio-based binder system for use in preparing foundry molds. In a preferred embodiment, the system includes the use of a) a polyermizable hydroxyl-containing component comprising a saccharide, b) an isocyanate component, and c) a catalyst, and preferably amine catalyst, component adapted to catalyze the polymerization of a) and b), in the presence of a foundry aggregate such as sand. The system can be used in any suitable manner, including in either a cold box process or no bake process as described herein.

1 - 11 . (canceled) 
     
     
         12 . A foundry mold for use in making a shaped metal article by metal casting, the foundry mold comprising the combination of a foundry aggregate and a binder comprising a polymer resin which is substantially free of polymerized phenol aldehyde and which comprises the reaction product, in the presence of the aggregate, of:
 a saccharide component which is substantially underivatized,   an isocyanate component, and   a catalyst component capable of catalyzing the polymerization of the saccharide component and the isocyanate component.   
     
     
         13 . The foundry mold of  claim 12 , wherein the reaction product is formed in the presence of water. 
     
     
         14 . The foundry mold of  claim 12 , wherein the saccharide component is selected from the group consisting of mono, di-, oligo-, and polysaccharides, including mixtures thereof. 
     
     
         15 . The foundry mold of  claim 14 , wherein the saccharide component comprises a polysaccharide selected from the group consisting of cellulose, levan, pullulan, corn syrup, and molasses. 
     
     
         16 . The foundry mold of  claim 12 , wherein the reaction product comprises about 10 to about 40 weight percent saccharide component. 
     
     
         17 . The foundry mold of  claim 16 , wherein the reaction product comprises about 15 to about 20 weight percent saccharide component. 
     
     
         18 . The foundry mold of  claim 12 , wherein the saccharide component includes a saccharide derivative. 
     
     
         19 . The foundry mold of  claim 12 , wherein the reaction product includes a co-polymerized non-saccharide polyol component. 
     
     
         20 . The foundry mold of  claim 19 , wherein the non-saccharide polyol component comprises a polyol selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, hexane 1,6-diol, 2methyl-1,3-propanediol, glycerol, mannitol, sorbitol, diethylene glycol, triethylene glycol, polyethylene glycols, polypropylene glycols, butylene, dibutylene, and polybutylene glycols. 
     
     
         21 . The foundry mold of  claim 20 , wherein the reaction product comprises about 15 to about 25% non-saccharide polyol component. 
     
     
         22 . The foundry mold of  claim 12 , wherein the reaction product comprises about 20 to about 70% by weight of an isocyanate component comprising one or more isocyanates selected from the group consisting of 2,4- and 2,6-diisocyanatotoluene (TDI) and their derivatives, methylenediphenyl 4,4′-, 2,4- and 2,2′-diisocyanates (MDI) and their derivatives, polymeric MDI's (PMDI), 1,5-naphthalene diisocyanate (NDI), 4,4′, 4″-triisocyanatotriphenylmethane and bis(3,5- diisocyanato-2-methylphenyl)methane, 1,6-hexamethylene diisocyanate (HDI), and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl(isophorone) isocyanate (IPDI). 
     
     
         23 . The foundry mold of  claim 12  wherein the catalyst component comprises a tertiary amine catalyst. 
     
     
         24 . The foundry mold of  claim 12  wherein the catalyst component is present in an amount sufficient to provide a foundry work time of between about 1 and about 30 minutes. 
     
     
         25 . The foundry mold of  claim 24 , wherein the catalyst component is present in an amount sufficient to provide a foundry work time of between about 4 and about 10 minutes. 
     
     
         26 . The foundry mold of  claim 12 , wherein the saccharide component is substantially free of volatile organic compounds and the reaction product is formed in the presence of water. 
     
     
         27 . The foundry mold of  claim 26 , wherein the saccharide component is substantially free of aromatic solvents. 
     
     
         28 . A process for making a foundry mold for use in making a metal article by metal casting, the foundry mold having a predetermined shape defining an open volume corresponding to the metal article to be cast, the process comprising forming a mixture into the predetermined shape, the mixture comprising:
 a foundry aggregate,   a saccharide component which is substantially underivatized,   an isocyanate component, and   a catalyst component capable of catalyzing polymerization of the saccharide component   and the isocyanate component to form a polyurethane binder,   
       and allowing the saccharide component, the isocyanate component and the catalyst component to react to form the polyurethane binder, thereby forming the foundry mold. 
     
     
         29 . The process of  claim 28 , wherein the foundry aggregate, the saccharide component, the isocyanate component and the catalyst component are formed into the mixture and thereafter the mixture so made is formed into said shape. 
     
     
         30 . The process of  claim 29 , wherein the mixture contains sufficient catalyst so that the foundry work time of the mixture is between about 1 and about 30 minutes. 
     
     
         31 . The process of  claim 28 , wherein the foundry aggregate, the saccharide component and the isocyanate component are combined, the composition so made is formed into said shape, and thereafter a catalyst component comprising a tertiary amine gas is passed through the shaped composition. 
     
     
         32 . The process of  claim 28 , wherein the mixture contains water. 
     
     
         33 . The process of  claim 28 , wherein the saccharide component is substantially free of volatile organic compounds. 
     
     
         34 . The process of  claim 33 , wherein the saccharide component is substantially free of aromatic solvents. 
     
     
         35 . A process for making a foundry mold for use in making a metal article by metal casting, the foundry mold having a predetermined shape defining an open volume corresponding to the metal article to be cast, the process comprising forming a mixture into the predetermined shape, the mixture comprising:
 a foundry aggregate selected from the group consisting of silica sand, lake sand, zircon, olivine, chromite, and mullite,   a saccharide component which is substantially underivatized, the saccharide component comprising a polysaccharide selected from the group consisting of cellulose, levan, pullulan, corn syrup, and molasses,   a non-saccharide polyol component comprising a polyol selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, hexane 1,6-diol, 2 methyl-1,3-propanediol, glycerol, mannitol, sorbitol, diethylene glycol, triethylene glycol, polyethylene glycols, polypropylene glycols, butylene, dibutylene, and polybutylene glycols,   an isocyanate component comprising one or more isocyanates selected from the group consisting of 2,4- and 2,6-diisocyanatotoluene (TDI) and their derivatives, methylenediphenyl 4,4′-, 2,4- and 2,2′-diisocyanates (MDI) and their derivatives, polymeric MDI's (PMDI), 1,5-naphthalene diisocyanate (NDI), 4,4′, 4″-triisocyanatotriphenylmethane and bis(3,5-diisocyanato-2-methylphenyl)methane, 1,6-hexamethylene diisocyanate (HDI), and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl(isophorone) isocyanate (IPDI), and   a catalyst component capable of catalyzing polymerization of the saccharide component and the isocyanate component to form a polyurethane binder,   
       and allowing the saccharide component, the non-saccharide polyol, the isocyanate component and the catalyst component to react to form the polyurethane binder, thereby forming the foundry mold. 
     
     
         36 . A process according to  claim 35 , wherein:
 the saccharide component is present in an amount between about 5 to about 65 weight percent of the binder,   the non-saccharide polyol component is present in an amount between about 1 and about 60% by weight of the binder,   and the isocyanate component is present in an amount between about 10 and about 80% by weight of the binder.   
     
     
         37 . A process according to  claim 35 , wherein:
 the saccharide component is present in an amount between about 10 to about 40 weight percent of the binder,   the non-saccharide polyol component is present in an amount between about 10 and about 50% by weight of the binder,   and the isocyanate component is present in an amount between about 20 and about 70% by weight of the binder.   
     
     
         38 . A process according to  claim 35 , wherein:
 the saccharide component is present in an amount between about 15 to about 20 weight percent of the binder,   the non-saccharide polyol component is present in an amount between about 15 and about 25% by weight of the binder, and   the isocyanate component is present in an amount between about 20 and about 70% by weight of the binder, and   the aggregate is present in an amount of at least about 70 weight percent of the foundry mold.   
     
     
         39 . A process for making a foundry mold for use in making a metal article by metal casting, the foundry mold having a predetermined shape defining an open volume corresponding to the metal article to be cast, the process comprising forming a mixture into the predetermined shape, the mixture comprising:
 a foundry aggregate comprising silica sand,   a saccharide component which is substantially underivatized, the saccharide component comprising corn syrup,   a non-saccharide polyol component comprising triethylene glycol,   an isocyanate component comprising one or more methylenediphenyl 4,4′-, 2,4- and 2,2′-diisocyanates (MDI) and their derivatives, and   a catalyst component capable of catalyzing polymerization of the saccharide component and the isocyanate component to form a polyurethane binder,   
       and allowing the saccharide component, the non-saccharide polyol, the isocyanate component and the catalyst component to react to form the polyurethane binder, thereby forming the foundry mold, 
       wherein:
 the saccharide component is present in an amount between about 15 to about 20 weight percent of the binder, the non-saccharide polyol component is present in an amount between about 15 and about 25% by weight of the binder, and the isocyanate component is present in an amount between about 20 and about 70% by weight of the binder, and 
 the mixture contains sufficient catalyst so that the foundry work time of the mixture is between about 1 and about 30 minutes, and 
 the aggregate is present at least about 70 weight percent of the foundry mold.