Amine salts of tertiary amino acids

#1. Field

#Polyurethanes, which are formed by reacting an isocyanate with a reactive hydrogen providing component, such as a polyol, have been widely used in preparing rigid and flexible foams, castings, adhesives and coatings. Typically, the reaction between the isocyanate and the polyol has been catalyzed by using various components such as amines, e.g. tertiary amines and organometallics, particularly organo tin compounds such as stannous octoate, dibutyl tin laurate, tin ethylhexanoate and so forth. The effectiveness of the catalyst is often measured by the cream time, which is the time required for the isocyanate and polyol syrup to turn from a clear solution to a creamy color; the gel time, which is the time required for polymer particles to form in the syrup; rise time, which is the time required for the syrup to rise to its maximum height; and cure time which is the time to reach a track-free state.

#In some applications for polyurethanes it is desirable to effect reaction in the shortest time possible and, therefore, catalysts having tremendous activity are desired. In some applications, though, as in the molding of intricate parts or large objects, it may be desirable to keep the polyurethane composition in a fluid state for an extended time to permit the composition to completely fill the mold or flow into the cracks and crevices of the mold. Then, once the mold is completely filled, it is desirable to effect polymerization of the polyurethane in the shortest time possible so that the finished parts can be removed and the mold recharged with new materials. In this regard, it is desirable to delay the intial reaction, but after reaction commences then catalyze the polymerization rate. To do this it is necessary to extend the cream time to permit the polyurethane composition to penetrate the cracks and crevices in the mold and to extend the gelation time as the polyurethane foam on gelling becomes intractable and resists molding. However, once the reaction beings, it is desirable to end up with a rise and cure time comparable to those achieved by active catalysts as this will permit greater productivity.

#The following examples are provided to illustrate preferred embodiments in the invention and are not intended to restrict the scope thereof. All parts are parts by weight, all percentages are expressed as weight percentages, and all temperatures are in .degree.C. unless otherwise specified.

#Bis-(hydroxyethyl)amino benzyl malonic acid was prepared conventionally in a flask equipped with a stirrer and reflux condenser by first charging 0.1 mol of malonic acid, 0.1 mol of diethanol amine and 100 cc methanol. The contents were warmed to a temperature of about 20.degree. C. and then 0.1 benzaldehyde were added to the flask and the reaction commenced. After refluxing the reaction mixture for 1 hour, the methanol was removed from the reaction mixture by coupling the flask to a vacuum source and heating to a temperature of about 50.degree. C. The residue remaining in the flask then was triturated in acetone and the resulting acid isolated by filtration.

#The bis-triethylenediamine salt of the acid was prepared by mixing 0.1 m of the methanolic solution of the acid with 0.2 m triethylene diamine at room temperature (25.degree. C.) for 30 minutes, after which the methanol was removed under reduced pressure.