Katsumi Tokumoto

New polyisocyanurate catalysts which exhibit high activity at low temperature

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.

Regioselective bromination of phenols

Abstract Regioselective bromination of phenols gave 2-bromo-, 4-bromo-, 2,6-dibromo-2,4-dibromo, 2-bromo-6-substituted, 4-bromo-2-substituted and 2,4-dibromo-6-substituted phenols, respectively. Especially, 2-bromo-, 2,6-dibromo- and 2-bromo-6-substituted phenols which were prepared via long steps, were obtained in NBS-amine (primary and secondary) system in high yields under ordinary conditions. The scope and their mechanisms were discussed.

Innovative Quaternary Ammonium and Metal Based Catalyst Systems for CFC Free Isocyanurate Foams

This paper explains and introduces novel quaternary ammonium and metal based catalyst systems in CFC free polyisocyanurate (PIR) rigid foam applications. CFC elimination in polyurethane (PUR) applications has successfully been achieved, in most cases, with the more environmentally acceptable HCFCs, hydrocarbons (HCs) and water (CO 2 ) blown systems. The survey of next generation HFC blowing agents still is expanding. In PIR foam applications, however, inferior foam properties, as well as the decline in flame resistance, in HCFCs, HCs and CO 2 blown systems, are major issues. In general, PIR foams are produced by complex reactions such as the trimerization of isocyanate, urethane and urea, which all proceed simultaneously. The catalyst plays an important role in the control of these reaction rates, foaming profiles and foam properties such as adhesive strength, dimensional stability and flammability resistance. A number of catalysts, such as alkali metals, quaternary ammonium compounds and tertiary amines, have been proposed and used in PIR rigid foam applications as trimerization catalysts. All catalysts cannot, however, always meet the present industrial requirements. For example, alkali metals exhibit high trimerization activity at high temperature but much less activity at lower temperature, which results in inadequate rise profiles and severe friability, namely inferior adhesive strength. Quaterary ammonium compounds and tertiary amine catalysts provide better rise profiles, flow properties and moldability, however, they exhibit lower trimerization activity products, less flame resistance property and strong odor. Tosoh Corporation has successfully developed several new innovations in quaternary ammonium, metal based catalysts, as well as a flowability analysis system, using a Long Range Laser Displacement (LLD) apparatus, which can be applied to HCFC-141b/CO 2 as well as all CO 2 blown PIR foam. This technology assists in the successful production of PIR foams with excellent physical properties, including high conversion of trimerization, as well as improved flame resistance, flowability and friability.