Bio-based binders for insulation and non-woven mats

Abstract

An aqueous binder composition is provided that includes a carbohydrate and a crosslinking agent. In exemplary embodiments, the carbohydrate-based binder composition may also include a catalyst, a coupling agent, a process aid, a crosslinking density enhancer, an extender, a moisture resistant agent, a dedusting oil, a colorant, a corrosion inhibitor, a surfactant, a pH adjuster, and combinations thereof. The carbohydrate may be natural in origin and derived from renewable resources. Additionally, the carbohydrate polymer may have a dextrose equivalent (DE) number from 2 to 20. In at least one exemplary embodiment, the carbohydrate is a water-soluble polysaccharide such as dextrin or maltodextrin and the crosslinking agent is citric acid. Advantageously, the carbohydrates have a low viscosity and cure at moderate temperatures. The environmentally friendly, formaldehyde-free binder may be used in the formation of insulation materials and non-woven chopped strand mats. A method of making fibrous insulation products is also provided.

1 . An aqueous binder composition comprising:
 from 40% to 95% by weight of maltodextrin having a dextrose equivalent number from 2 to 14, and a number average molecular weight of from 1,000 to 8,000; and   from 5% to 40% by weight of a single crosslinking agent, the single crosslinking agent selected from polycarboxylic acids, salts of polycarboxylic acid, anhydrides, citric acid, salts of citric acid, adipic acid, salts of adipic acid, polyacrylic acid, salts of polyacrylic acid, and polyacrylic acid based resins;   wherein the aqueous binder composition is devoid of additional crosslinking agents,   wherein the binder composition has a pH of from 1 to 2.5, and   wherein the weight percentages are based upon the weight of total solids of the binder composition.   
     
     
         2 . The binder composition of  claim 1 , wherein the single crosslinking agent is selected from the group consisting of citric acid, salts of citric acid, polyacrylic acid, and salts of polyacrylic acid. 
     
     
         3 . The binder composition of  claim 1 , wherein the single crosslinking agent has a number average molecular weight of from 90 g/mol to 10,000 g/mol. 
     
     
         4 . The binder composition of  claim 1 , wherein the binder composition further comprises one or more of a coupling agent, a process aid, an extender, a pH adjuster, a catalyst, a crosslinking density enhancer, a deodorant, an antioxidant, a dust suppressing agent, a biocide, a corrosion inhibitor, and a moisture resistant agent. 
     
     
         5 . The binder composition of  claim 4 , wherein the process aid comprises a polyol. 
     
     
         6 . The binder composition of  claim 4 , wherein the process aid comprises at least one of glycerol, 1,2,4-butanetriol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, and polyethylene glycol. 
     
     
         7 . The binder composition of  claim 6 , wherein the process aid comprises glycerol. 
     
     
         8 . The binder composition of  claim 4 , wherein the catalyst comprises a sodium hypophosphite catalyst. 
     
     
         9 . The binder composition of  claim 4 , wherein the coupling agent comprises a silane coupling agent. 
     
     
         10 . An aqueous binder composition comprising:
 from 40% to 95% by weight of maltodextrin having a dextrose equivalent number from 2 to 14, and a number average molecular weight of from 1,000 to 8,000; and   from 5% to 40% by weight of one or more crosslinking agents, the crosslinking agents selected from polycarboxylic acids, salts of polycarboxylic acid, anhydrides, citric acid, salts of citric acid, adipic acid, salts of adipic acid, polyacrylic acid, salts of polyacrylic acid, and polyacrylic acid based resins;   wherein the binder composition has a pH of from 1 to 2.5, and   wherein the weight percentages are based upon the weight of total solids of the binder composition.   
     
     
         11 . The binder composition of  claim 10 , wherein the one or more crosslinking agents are selected from the group consisting of citric acid, salts of citric acid, polyacrylic acid, and salts of polyacrylic acid. 
     
     
         12 . The binder composition of  claim 10 , wherein the binder composition further comprises one or more of a coupling agent, a process aid, an extender, a pH adjuster, a catalyst, a crosslinking density enhancer, a deodorant, an antioxidant, a dust suppressing agent, a biocide, a corrosion inhibitor, and a moisture resistant agent. 
     
     
         13 . The binder composition of  claim 12 , wherein the process aid comprises a polyol. 
     
     
         14 . The binder composition of  claim 12 , wherein the process aid comprises at least one of glycerol, 1,2,4-butanetriol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, and polyethylene glycol. 
     
     
         15 . The binder composition of  claim 14 , wherein the process aid comprises glycerol. 
     
     
         16 . An insulation product comprising:
 a plurality of glass fibers; and   a binder composition at least partially coating the plurality of glass fibers, the binder composition comprising the reaction product of:
 from 40% to 95% by weight of maltodextrin having a dextrose equivalent number from 2 to 14, and a number average molecular weight of from 1,000 to 8,000; and 
 from 5% to 40% by weight of one or more crosslinking agents, the crosslinking agents selected from polycarboxylic acids, salts of polycarboxylic acid, anhydrides, citric acid, salts of citric acid, adipic acid, salts of adipic acid, polyacrylic acid, salts of polyacrylic acid, and polyacrylic acid based resins; 
 wherein the binder composition in an uncured state has a pH of from 1 to 2.5, and 
 wherein the weight percentages are based upon the weight of total solids of the binder composition. 
   
     
     
         17 . The insulation product of  claim 16 , wherein the one or more crosslinking agents consists of a single crosslinking agent. 
     
     
         18 . The insulation product of  claim 17 , wherein the single crosslinking agent is selected from the group consisting of polycarboxylic acids, salts of polycarboxylic acid, anhydrides, citric acid, salts of citric acid, adipic acid, salts of adipic acid, polyacrylic acid, salts of polyacrylic acid, and polyacrylic acid based resins, and
 wherein the aqueous binder composition is devoid of additional crosslinking agents.   
     
     
         19 . The insulation product of  claim 16 , wherein the binder composition further comprises one or more of a coupling agent, a process aid, an extender, a pH adjuster, a catalyst, a crosslinking density enhancer, a deodorant, an antioxidant, a dust suppressing agent, a biocide, a corrosion inhibitor, and a moisture resistant agent. 
     
     
         20 . The insulation product of  claim 19 , wherein the process aid comprises at least one of glycerol, 1,2,4-butanetriol, 1,4-butanediol, 1,2-propanediol, 1,3-propanediol, and polyethylene glycol.