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, 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. A cured binder composition prepared by heating at a temperature of 175° to 300° C. a substantially alkaline aqueous, formaldehyde free composition comprising a mixture of:
(1) a hydrolyzed copolymer of maleic anhydride and a vinyl aromatic compound, said hydrolyzed copolymer having been solubilized using ammonia, a secondary alkanolamine, a tertiary alkanolamine, or a mixture thereof and
(2) a polyol selected from diethanolamine, triethanolamine, or a mixture thereof wherein said cured binder composition cures at a temperature between 175° and 300° C. and has crosslinks that form through esterification reactions between the copolymer and the polyol.
2. The cured binder composition of claim 1 wherein said hydrolzed copolymer was solubilized using diethanolamine, triethanolamine, or a mixture thereof.
3. The cured binder composition of claim 2 wherein the vinyl aromatic compound is styrene.
4. The cured binder composition of claim 3 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.
5. The cured binder composition of claim 4 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.
6. The cured binder composition of claim 5 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.
7. The cured binder composition of claim 4 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.
8. The cured binder composition of claim 7 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.
9. The cured binder composition of claim 4 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.
10. The cured binder composition of claim 1 wherein the polyol is selected from the group consisting of 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 and mixtures thereof.
11. The cured binder composition of claim 10 wherein the polyol is selected from the group consisting of diethanolamine, triethanolamine and mixtures thereof and the hydrolyzed copolymer was solubilized using diethanolamine, triethanolamine, or a mixture thereof.
12. The cured binder composition of claim 3 wherein the polyol is selected from the group consisting of 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 and mixtures thereof.
13. The cured binder composition of claim 12 wherein the polyol is selected from the group consisting of diethanolamine, triethanolamine and mixtures thereof and the hydrolyzed copolymer was solubilized using diethanolamine, triethanolamine, or a mixture thereof.
14. The cured binder composition of claim 1 further containing heat resistant fibers.
15. The cured binder composition of claim 1 wherein the heat resistant fibers are glass fibers.
16. The cured binder composition of claim 1 wherein the hydrolyzed copolymer was solubilized using triethanolamine and the triethanolamine forms crosslinks by esterification reactions with the copolymer of maleic anhydride and a vinyl aromatic compound.
17. A cured binder composition prepared by heating at a temperature of 175° to 300 20 C. a substantially alkaline aqueous, formaldehyde free composition comprising a mixture of:
(1) a hydrolyzed copolymer of maleic anhydride and a vinyl aromatic compound
(2) a polyol selected from diethanolamine, triethanolamine, or a mixture thereof wherein said cured binder composition cures at a temperature between 175° and 300 °C. and has crosslinks that form through esterification reactions between the copolymer and the polyol.