| 摘要 |
A solid urea-formaldehyde resin is provided, having a degree of condensation of 25% to 45%. A process for making the resin is also described and includes several steps. Urea and formaldehyde is first reacted with a molar ratio of U:F of 1:2.5 or more then concentrated. Further urea is added to reduce the ratio to the range 1:1.1 to 1:2 and further concentration is achieved without precipitation of solid resin by the use of a stabilization agent. |
