METHOD FOR MANUFACTURING 1,5-NAPHTHALENE DIISOCYANATE PREPOLYMER WITH HIGH NCO CONTENT AND STORAGE STABLE NDI PREPOLYMER WITH HIGH NCO CONTENT MANUFACTURED THEREBY

摘要

The present invention relates to a method for manufacturing room-temperature storage stable NDI prepolymer, the method comprising the steps of synthesizing NDI prepolymer (A) with an NCO content of 4.3 to 4.5% by making 100 wt% of polyol with a molecular weight of 1,600 to 2,000 react with 24.0 to 27.5 wt% of 1,5-naphthalene diisocyanate (NDI) for 15 to 20 minutes; synthesizing NDI prepolymer (B) having the NCO content increased to 5.0 to 5.5% by adding 2.5 to 3.5 wt% of low-melting-point diisocyanate to the NDI prepolymer (A) with respect to 100 wt% of the polyol and churning the mixture for five to 10 minutes; and naturally cooling the NDI prepolymer (B) to 80 to 90°C within 30 minutes and naturally cooling the NDI prepolymer to room temperature. The NDI prepolymer manufactured according to the present invention has a high NCO content proper for manufacturing NDI polyurethane microcellular foam via a quasi-prepolymer method, has viscosity and the NCO content not changed greatly even if the NDI prepolymer is kept at room temperature for several months, and can be dissolved in transparent solution state where NDI is not precipitated.;COPYRIGHT KIPO 2015