Low Emissions Polyurethane Foam Made with Isocyanate Reactive Amine Catalyst
Tertiary amine catalysts having isocyanate reactive groups that are capable of forming thermally stable covalent bonds able to withstand temperatures from 120° C. and higher and up to 250° C. are disclosed. These catalyst can be used to produce polyurethane foam having the following desirable characteristics: a) very low chemical emissions over a wide range of environmental conditions and isocyanate indexes (e.g., indexes as low as 65 but higher than 60) ; b) sufficient hydrolytic stability to maintain the catalyst covalently bound to foam without leaching of tertiary amine catalyst when foam is exposed to water or aqueous solutions even at temperatures higher than ambient (temperature range 25° C. to 90° C.); and c) stable contact interface between the polyurethane polymer and other polymers (for example polycarbonate) with minimal migration of tertiary amine catalyst from polyurethane polymer to other polymers yielding no noticeable polymer deterioration at the point of contact even under conditions of heat and humidity.
1 . A catalyst composition comprising N,N-bis(dimethylaminopropyl)-N-(3-aminopropyl)-amine.
2 . A catalyst composition having a chemical structure of [Me 2 N—(CH 2 ) 3 ] 2 N—(CH 2 ) 3 —NH 2 wherein Me is CH 3 group.
3 . The catalyst composition of claim 1 further comprising at least one blowing catalyst
4 . The catalyst composition of claim 3 further comprising at least one gelling catalyst.
5 . The catalyst composition of claim 4 wherein the blowing catalyst and the gelling catalyst comprise non-emissive tertiary amines.
6 . A method for making a catalyst comprising contacting acrylonitrile and bis(dimethylaminopropyl)amine under conditions sufficient to obtain bis(dimethyleaminopropyl)-cyanoethyl-amine; and contacting bis(dimethyleaminopropyl)-cyanoethyl-amine with hydrogen under conditions sufficient to obtain N,N-bis(dimethylaminopropyl)-N-(3-aminopropyl)-amine.
7 . A method for making a polyurethane foam comprising contacting at least one polyol and at least one polyisocyanate in the presence of a catalyst comprising N,N-bis(dimethylaminopropyl)-N-(3-aminopropyl)-amine.
8 . The method of claim 7 wherein the polyisocyanate has an NCO index of about 60 to 65.
9 . The method of claim 7 wherein the polyisocyanate has an NCO index of about 90 to 110.
10 . A foam produced in accordance with the method of claim 7 wherein the foam is free from amine emissions when measured in accordance with VDA 278.
11 . A pre-mix comprising at least one polyol, a catalyst composition comprising N,N-bis(dimethylaminopropyl)-N-(3-aminopropyl)-amine and at least one tertiary amine, at least one silicone surfactant, water and at least one crosslinker.
12 . The pre-mix of claim 11 wherein the crosslinker comprises diethanolamine.