Formaldehyde free binder
View Patent ↗An aqueous, formaldehyde-free binder composition comprising a modified copolymer of maleic anhydride and a vinyl aromatic compound such as styrene, the copolymer being modified by reaction with a primary alkanolamine, such as monoethanolamine (MEA), to produce a modified copolymer that is self-curing and cures as a consequence of cross-linking, esterification reactions between pendant carboxyls and hydroxyl groups on the solubilized (hydrolyzed) modified copolymer chains; the invention also relates to the corresponding method of using the binder composition for making fiber products, especially fiberglass insulation.
1. A cured binder composition comprising
(1) primary alkanolamine-modified copolymer of maleic anhydride and a vinyl aromatic compound, and
(2) a polyol,
wherein said binder composition is cured at a temperature between 175° and 300° C. and has crosslinks that form through esterification reactions between the primary alkanolamine-modified copolymer and the polyol.
2. The cured binder composition of claim 1 wherein the primary alkanolamine used to modify the copolymer is selected from the group consisting of 2-(2-aminoethoxy)ethanol, aminoethyl ethanolamine, aminobutanol, monoethanolamine and mixtures thereof.
3. The cured binder composition of claim 2 wherein the primary alkanolamine-modified copolymer is a monoethanolamine-modified copolymer.
4. The cured binder composition of claim 3 wherein said monoethanolamine-modified copolymer is prepared by reacting a copolymer of maleic anhydride and a vinyl aromatic compound with monoethanolamine.
5. The cured binder composition of claim 4 wherein the vinyl aromatic compound is styrene.
6. The cured binder composition of claim 5 wherein from 0.01 to 0.4 mole of monoethanolamine is reacted with the copolymer of maleic anhydride and styrene per mole of maleic anhydride monomer of said copolymer.
7. The cured binder composition of claim 6 wherein the copolymer of maleic anhydride and styrene contains from 7 mole % to 50 mole % maleic anhydride monomer and from 50 mole % to 93 mole % styrene monomer.
8. The cured binder composition of claim 7 wherein the copolymer of maleic anhydride and styrene contains an additional unsaturated carboxylic acid monomer in an amount of less than 30 mole % based on the amount of maleic anhydride.
9. The cured binder composition of claim 8 wherein the additional unsaturated carboxylic acid monomer 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.
10. The cured binder composition of claim 7 wherein the copolymer of maleic anhydride and styrene contains another hydrophobic vinyl monomer in an amount of less than 30 mole % based on the amount of vinyl aromatic monomer.
11. The cured binder composition of claim 10 wherein the hydrophobic vinyl monomer is selected from the group consisting 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.
12. The cured binder composition of claim 7 wherein the copolymer of maleic anhydride and styrene contains from 20 mole % to 40 mole % maleic anhydride monomer and from 60 mole % to 80 mole % styrene monomer.
13. The cured binder composition of claim 1 wherein the polyol is selected from the group consisting of 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, triethanolamine, diethanolamine, ethyl diethanolamine, methyl diethanolamine, and mixtures thereof.
14. The cured, binder composition of claim 13 wherein the polyol is selected from the group consisting of ethyl diethanolamine, methyl diethanolamine, diethanolamine, triethanolamine and mixtures thereof.
15. The cured, binder composition of claim 14 wherein the modified copolymer has been solubilized by the diethanolamine, triethanolamine, or a mixture thereof.
16. The cured binder composition of claim 3 further comprising a polyamino extender.
17. The cured binder composition of claim 16 wherein the polyamino extender is urea.
18. The cured binder composition of claim 7 wherein the polyol is selected from the group consisting of 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, triethanolamine, diethanolamine, ethyl diethanolamine, methyl diethanolamine, and mixtures thereof.
19. The cured binder composition of claim 18 wherein the polyol is selected from the group consisting of triethanolamine, diethanolamine, ethyl diethanolamine, methyl diethanolamine, and mixtures thereof.
20. The cured binder composition of claim 9 wherein the modified copolymer has been solubilized by the diethanolamine, triethanolamine, or mixture thereof.
21. The cured binder composition of claim 7 further comprising a polyamino extender.
22. The cured binder composition of claim 21 wherein the polyamino extender is urea.
23. The cured binder composition of claim 1 wherein the polyol is selected from diethanolamine, triethanolamine, or a mixture thereof.
24. The cured binder composition of claim 1 further containing heat resistant fibers.
25. The cured binder composition of claim 24 wherein the heat resistant fibers are glass fibers.
26. The cured binder composition of claim 1 wherein the binder composition is a substantially alkaline, formaldehyde free composition.