Patent ID: 7138435

Claim:
A method of decomposing a thermosetting resin by a decomposer, comprising the steps of: pre-heating the thermosetting resin up to a preheating temperature T 0 ; kneading the pre-heated thermosetting resin together with a decomposer, and concurrently heating a mixture comprising the thermosetting resin and the decomposer up to a kneading temperature T 1 , thereby allowing a reaction to take place between the decomposer and the thermosetting resin to obtain a kneaded matter wherein the decomposer becomes consumed; and heating said kneaded matter to a maximum temperature T 2 to decompose the thermosetting resin; wherein: said pre-heating temperature T 0 is not higher than the boiling temperature of said decomposer; said kneading temperature T 1 is not lower than said pre-heating temperature T 0 but is lower than the thermal decomposition temperature of the thermosetting resin; said maximum temperature T 2 is lower than the thermal decomposition temperature of the thermo setting resin; and said pre-heating of the thermosetting resin is performed under the following conditions of temperature T 0 and time t: 100° C.≦T0<260° C. 0.5 min≦t≦7 min, and wherein when said thermosetting resin is a urethane resin, urethane moieties thereof are decomposed.