Bio-based binders including carbohydrates and a pre-reacted product of an alcohol or polyol and a monomeric or polymeric polycarboxylic acid
An environmentally friendly, formaldehyde-free, aqueous binder composition that includes a carbohydrate, a crosslinking agent, and a pre-reacted product of an alcohol or polyol and monomeric or polymeric polycarboxylic acid or polyglycerol is provided. The pre-reacted product may include glycerol and esters of citric acid such a monoglyceryl citrate, diglyceryl citrate, and triglyceryl citrate as well as other higher molecular weight citric acid-based esters. The inclusion of the pre-reacted product in the binder composition helps to speed the crosslinking reaction, induces faster water evaporation, decreases the viscosity of the binder, helps to reduce the amount of water needed for application of the binder, decreases tackiness, and helps to achieve a maximum vertical expansion of the insulation pack in the transfer zone. The binder composition may be used in the formation of insulation materials and non-woven chopped strand mats.
1. A fibrous insulation product comprising:
a plurality of randomly oriented fibers; and
a binder composition applied to at least a portion of said fibers, said binder composition comprising the reaction product of:
at least one carbohydrate having a dextrose equivalent number from 2 to 20;
from 1 to 40 wt. % of at least one crosslinking agent, based on the weight of the total solids in the binder composition, wherein the crosslinking agent comprises one or more of polycarboxylic acids, salts of polycarboxylic acid, anhydrides, citric acid, salts of citric acid, adipic acid, salts of adipic acid, polyacrylic acid, or salts of polyacrylic acid; and
from 10 to 60 wt. % of a pre-reacted product comprising the reaction product of a polyol with citric acid, based on the weight of the total solids in the binder composition, said polyol comprising one or more of glycerol, polyglycerol, triethanolamine, sorbitol, polyethylene glycol, propylene glycol, or ethylene glycol, and wherein said polyol and said citric acid being present in a molar ratio from about 1.5-3.0 moles polyol: 1 mole citric acid,
wherein the pre-reacted product comprises:
from 5 to 25 wt. % of unreacted polyol, based on the weight of the pre-reacted product; and
less than 5 wt. % unreacted citric acid, based on the weight of the pre-reacted product.
2. The fibrous insulation product of claim 1 , wherein said binder composition in a cured state comprises at least one polyester.
3. The fibrous insulation product of claim 1 , wherein said polyol comprises one or more of glycerol, polyglycerol, triethanolamine, or sorbitol.
4. The fibrous insulation product of claim 1 , wherein said at least one carbohydrate is a water-soluble polysaccharide comprising one or more of pectin, dextrin, maltodextrin, or starch.
5. The fibrous insulation product of claim 1 , wherein said crosslinking agent comprises citric acid, salts of citric acid, or combinations thereof.
6. The fibrous insulation product of claim 1 , wherein said binder composition further comprises one or more of a one coupling agent, a moisture resistant agent, a dust suppression agent, a catalyst, an inorganic acid, an organic acid, an inorganic base, or an organic base.
7. The fibrous insulation product of claim 1 , wherein said insulation product is free of added formaldehyde.
8. The fibrous insulation product of claim 1 , wherein the pre-reacted product comprises:
(i) from 5 to 25 wt % of unreacted glycerol based on the weight of the pre-reacted product;
(ii) from 10 to 70 wt % of a mixture of monoglyceryl citrate, diglyceryl citrate, and triglyceryl citrate based on the weight of the pre-reacted product; and
(iii) less than 5 wt % citric acid based on the weight of the pre-reacted product, wherein the pre-reacted product has a weight average molecular weight of from 1500 to 5000 Daltons.
9. The fibrous insulation product of claim 8 , wherein the pre-reacted product comprises from 12 to 50 wt % of a mixture of monoglyceryl citrate, diglyceryl citrate, and triglyceryl citrate based on the weight of the pre-reacted product.
10. A non-woven mat comprising:
a plurality of randomly oriented glass fibers in the form of a mat having a first major surface and a second major surface; and
a binder composition at least partially coating said first major surface of said mat, said binder composition comprising the reaction product of:
from 1 to 40 wt. % of at least one crosslinking agent, based on the weight of the total solids in the binder composition, wherein the crosslinking agent comprises one or more of polycarboxylic acids, salts of polycarboxylic acid, anhydrides, citric acid, salts of citric acid, adipic acid, salts of adipic acid, polyacrylic acid, or salts of polyacrylic acid; and
from 10 to 60 wt. % of a pre-reacted product comprising the reaction product of a polyol with citric acid, based on the weight of the total solids in the binder composition, said polyol comprising one or more of glycerol, polyglycerol, triethanolamine, sorbitol, polyethylene glycol, propylene glycol, or ethylene glycol, and wherein said polyol and said citric acid being present in a molar ratio from about 1.5-3.0 moles polyol: 1 mole citric acid,
wherein the pre-reacted product comprises:
from 5 to 25 wt. % of unreacted polyol, based on the weight of the pre-reacted product; and
less than 5 wt. % unreacted citric acid, based on the weight of the pre-reacted product.
11. The non-woven mat of claim 10 , wherein said binder composition in a cured state comprises at least one polyester.
12. The non-woven mat of claim 10 , wherein said polyol comprises one or more of glycerol, polyglycerol, triethanolamine, or sorbitol.
13. The non-woven mat of claim 10 , wherein said at least one carbohydrate is a water-soluble polysaccharide comprising one or more of pectin, dextrin, maltodextrin, or starch.
14. The non-woven mat of claim 10 , wherein said crosslinking agent comprises citric acid, salts of citric acid, or combinations thereof.
15. The non-woven mat of claim 10 , wherein said binder composition further comprises one or more of a one coupling agent, a moisture resistant agent, a dust suppression agent, a catalyst, an inorganic acid, an organic acid, an inorganic base, or an organic base.
16. The non-woven mat of claim 10 , wherein said insulation product is free of added formaldehyde.
17. The non-woven mat of claim 10 , wherein the pre-reacted product comprises:
(i) from 5 to 25 wt % of unreacted glycerol based on the weight of the pre-reacted product;
(ii) from 10 to 70 wt % of a mixture of monoglyceryl citrate, diglyceryl citrate, and triglyceryl citrate based on the weight of the pre-reacted product; and
(iii) less than 5 wt % citric acid based on the weight of the pre-reacted product, wherein the pre-reacted product has a weight average molecular weight of from 1500 to 5000 Daltons.
18. The non-woven mat of claim 17 , wherein the pre-reacted product comprises from 12 to 50 wt % of a mixture of monoglyceryl citrate, diglyceryl citrate, and triglyceryl citrate based on the weight of the pre-reacted product.