Formaldehyde free binder
View Patent ↗An aqueous binder composition, useful for making fiber products, especially fiberglass insulation, comprising an aqueous substantially alkaline (pH of at least 5.0) solution of a polyol and a hydrolyzed (solubilized) copolymer of maleic anhydride and a vinyl aromatic compound, preferably styrene (i.e., a SMA copolymer); the copolymer is solubilized using ammonia, an ammine, a primary alkanolamines (preferably monoethanolamine), a secondary alkanolamine (preferably diethanolamine (DEA)), a tertiary alkanolamine (preferably triethanolamine (TEA)), or a mixture thereof and the binder composition is cured as a consequence of cross-linking, esterification reactions between pendant carboxyls on the solubilized (hydrolyzed) copolymer (SMA) chains and hydroxyl groups of the polyol, including the diethanolamine and/or triethanolamine preferably used in the solubilization of the SMA.
1. An aqueous binder composition comprising a polyol and an aqueous solution of a hydrolyzed copolymer of maleic anhydride and a vinyl aromatic compound, wherein:
the hydrolyzed copolymer is hydrolyzed using an alkaline substance comprising a primary alkanolamine and a tertiary alkanolamine,
the aqueous solution of the hydrolyzed copolymer has a pH above 7.0 and comprises an amide functional group,
the polyol comprises a monosaccharide, and
the aqueous binder composition is formaldehyde free.
2. The aqueous binder composition of claim 1 , wherein the alkaline substance further comprises ammonia, one or more amines, or a mixture thereof.
3. The aqueous binder composition of claim 1 , wherein the vinyl aromatic compound is styrene.
4. The aqueous binder composition of claim 1 , wherein:
the hydrolyzed copolymer contains from 7 mole % to 50 mole % maleic anhydride and from 50 mole % to 93 mole % styrene,
the alkaline substance further comprises aqueous ammonia, and
the aqueous solution of the hydrolyzed copolymer comprises an imide functional group.
5. The aqueous binder composition of claim 4 , wherein the hydrolyzed copolymer further contains an unsaturated carboxylic acid in an amount less than 30 mole %, based on the amount of maleic anhydride.
6. The aqueous binder composition of claim 5 , wherein the unsaturated carboxylic acid is selected from the group consisting of: aconitic acid, itaconic acid, acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, citraconic acid, fumaric acid, lower alkyl esters thereof, and mixtures thereof.
7. The aqueous binder composition of claim 4 , wherein the hydrolyzed copolymer further contains a non-styrenic vinyl compound in an amount less than 30 mole %, based on the amount of styrene.
8. The aqueous binder composition of claim 7 , wherein the non-styrenic vinyl compound is selected from the group consisting of: vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl laurate, vinyl stearate, butadiene, isoprene, ethylene, propylene, cyclohexene, vinyl chloride, vinylidene chloride, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, acrylonitrile, methacrylonitrile, and mixtures thereof.
9. The aqueous binder composition of claim 1 , wherein the hydrolyzed copolymer contains from 20 mole % to 40 mole % maleic anhydride and from 60 mole % to 80 mole % styrene.
10. The aqueous binder composition of claim 1 , wherein the polyol further comprises diethanolamine, triethanolamine, ethyl diethanolamine, methyl diethanolamine, ethylene glycol, diethylene glycol, triethylene glycol, hydroxy terminated polyethyleneoxide, glycerine, pentaerythritol, trimethylol propane, sorbitol, a polysaccharide, polyvinyl alcohol, resorcinol, catechol, pyrogallol, glycollated ureas, 1,4-cyclohexane diol, or mixtures thereof.
11. The aqueous binder composition of claim 1 , wherein the monosaccharide comprises glucose, fructose, or a mixture thereof.
12. The aqueous binder composition of claim 1 , wherein the monosaccharide comprises glucose.
13. The aqueous binder composition of claim 1 , wherein a molar ratio between pendant carboxyl (—COOH) groups of the copolymer and hydroxyl (—OH) groups of the polyol is from about 2:1 to about 1:2.
14. The aqueous binder composition of claim 1 , wherein a molar ratio between pendant carboxyl (—COOH) groups of the copolymer and hydroxyl (—OH) groups of the polyol is from about 1.5:1 to about 1:1.5.
15. The aqueous binder composition of claim 1 , wherein the aqueous solution of the hydrolyzed copolymer further comprises an imide functional group.
16. The aqueous binder composition of claim 1 , wherein the primary alkanolamine comprises monethanolamine and the tertiary alkanolamine comprises triethanolamine.
17. The aqueous binder composition of claim 1 , wherein the primary alkanolamine comprises monoethanolamine and the tertiary alkanolamine comprises triethanolamine, and wherein the polyol comprises glucose.
18. The aqueous binder composition of claim 1 , wherein the primary alkanolamine comprises monoethanolamine and the tertiary alkanolamine comprises triethanolamine, wherein the hydrolyzed copolymer contains from 20 mole % to 40 mole % maleic anhydride and from 60 mole % to 80 mole % styrene, and wherein the monosaccharide comprises glucose.
19. The aqueous binder composition of claim 1 , wherein the primary alkanolamine comprises monoethanolamine and the tertiary alkanolamine comprises triethanolamine, wherein a molar ratio between pendant carboxyl (—COOH) groups of the copolymer and hydroxyl (—OH) groups of the polyol is from about 1.5:1 to about 1:1.5, and wherein the monosaccharide comprises glucose.
20. The aqueous binder composition of claim 1 , wherein the primary alkanolamine comprises monoethanolamine and the tertiary alkanolamine comprises triethanolamine, wherein the aqueous solution of the hydrolyzed copolymer further comprises an imide functional group, wherein a molar ratio between pendant carboxyl (—COOH) groups of the copolymer and hydroxyl (—OH) groups of the polyol is from about 1.5:1 to about 1:1.5, wherein the monosaccharide comprises glucose, and wherein the hydrolyzed copolymer contains from 20 mole % to 40 mole % maleic anhydride and from 60 mole % to 80 mole % styrene.