Methods for reducing aldehyde emissions in polyurethane foams
AssigneeDow Global Technologies LLC
InventorsZhengming Tang, Hongliang Chen, Jian Zou, Shaoguang Feng, Degang Zhang, Ping Zhang
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Abstract
Polyurethane foams are made by curing a reaction mixture that contains an aromatic polyisocyanate, at least one isocyanate-reactive material having an average functionality of at least 2 and an equivalent weight of at least 200 per isocyanate-reactive group, at least one blowing agent, at least one surfactant, at least one catalyst, and certain aldehyde-suppressing additives. Foams so produced emit low levels of formaldehyde, acetaldehyde and propionaldehyde.
Claims14
A process for producing a polyurethane foam comprising forming a reaction mixture that contains an aromatic polyisocyanate, at least one isocyanate-reactive material having an average functionality of at least 2 and an equivalent weight of at least 200 per isocyanate-reactive group, at least one blowing agent, at least one surfactant and at least one catalyst, and curing the reaction mixture in the presence of (i) at least one hindered amine represented by structure I:
- wherein Y is hydrogen, alkyl, or →O, R1 and R3 each are independently alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl;
- R2 and R4 each are independently hydrogen, alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl;
- m is at least 1, preferably 1 or 2, A is H, —OH, —NH2, alkyl or a chemical bond when m is 1 and chemical bond or a linking group when m is 2 or more, and Z is —CH2— or a chemical bond, and ii) at least one compound represented by structure II:
- wherein R6 and R7 are independently hydrogen, alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl, and R8 is:
- wherein R9, R10 and R11, are each independently hydrogen, alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl and R9 and R10, and/or R10 and R11 optionally form rings.
A method for reducing aldehyde emissions from a polyurethane foam, comprising:
- a) combining (i) at least one hindered amine represented by structure I:
- wherein Y is hydrogen, alkyl, or →O, R1 and R3 each are independently alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl;
- R2 and R4 each are independently hydrogen, alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl;
- m is at least 1, A is H, —OH, —NH2, alkyl or a chemical bond when m is 1 and chemical bond or a linking group when m is 2 or more, and Z is —CH2— or a chemical bond, and ii) at least one compound represented by structure II:
- wherein R6 and R7 are independently hydrogen, alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl, and R8 is:
- wherein R9, R10 and R11, are each independently hydrogen, alkyl, aryl-substituted alkyl, aryl or alkyl-substituted aryl with the proviso that R9 and R10, and/or R10 and R11 may form rings,
- with at least one isocyanate-reactive material having an average functionality of at least 2 and an equivalent weight of at least 200 per isocyanate-reactive group to form a mixture and then b) combining the mixture from step a) with at least one organic polyisocyanate and curing the resulting combination in the presence of at least one blowing agent, at least one surfactant and at least one catalyst to form a polyurethane foam.
Dependencies are inferred from the claim text.