| 摘要 |
The odorless urea resin adhesive for paper making, plywood and fiber, was prepared whose residual unreacted formalin was decreased to 1%. After urea and formaldehyde aqueous solution were mixed completely, the aqueous solution was reacted at 80 deg.C for 80-90 minutes in the presence of barium hydroxide catalyst, followed by dropping 37% hydrochloride. A mixed solution of NH4OH, NaOH and Na2CO3, and a mixed solution of Ba(OH)2 and Na2CO3 were put into above solution, cooled and dehydrated at 45 deg.C, 60 mmHg orderly to give the urea resin adhesive.
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