New Polyisocyanurate Catalysts Which Exhibit High Activity at Low Temperature

Abstract

In polyisocyanurate foam production, alkali metal catalysts of organic carboxylic acids and hydroxyalkyltrimethyl quaternary ammonium salts are traditional standards as polyisocyanurate foam catalysts. The activity of these catalysts, however, is not efficient at low temperature. Therefore, the initiation reactions are extremely delayed, and the flowability of the foam system is far too inferior. In addition, the foam exhibits shrinkage when the thickness of the sprayed layer was thin and the temperature was low while applying the sprayed foams. The combination of other tertiary amine catalysts could improve the flowability; however, the flammability of the foam would be a hazard because the isocyanurate reaction has not fully progressed.

For the improvement of the above-mentioned problems, Tosoh Corp. has developed several new quaternary ammonium salt compounds, such as Toyocat-TR20. TR20, however, should be used in conjunction with an alkali metal co-catalyst. Presently, Tosoh has succeeded in developing another new catalyst having even higher catalytic activity at low temperature, which can replace the use of the alkali metal catalyst. The new catalyst provides the low temperature dependency in the isocyanurate reaction activity compared to the traditional isocyanurate catalysts. The new catalyst provides the following advantages:

1. The catalytic activity is high.

2. The isocyanurate reaction activity at low temperature is high.

3. The initial foaming reaction is improved, thereby the rise profile is now smooth.

In this report, new quaternary ammonium salts will be introduced with comparison data using the FT-IR analytical methods, as well as the evaluation in panel and sprayed foams.