| 摘要 |
A polyurethane sealing composition comprises (1) A prepolymer, formed by reacting toluene diisocyanate with a polyester derived from adipic acid, ethylene glycol and propylene glycol, is mixed first with carbon black and cellulose acetate butyrate in a solvent and then with methylene-bis-orthochloro-aniline (a cross-linking agent). (2) Methylene diphenylene diisocyanate may be used in place of toluene diisocyanate, and the cross-linking agent may be methylene-bis-orthochlorobenzidine. (3) In addition, the prepolymer is also compounded with SiO2. |
