| 摘要 |
The present invention relates to a new process for modification of lignins, particularly from sulfite waste liquor, and preparation of lignin phenol-formaldehyde resin, i.e. thermosetting resins for which some or all of the phenol is replaced by the modified lignin. The lignin is modified in two steps. In the first step, a graft-copolymerization is performed with different kinds of unsaturated monomers containing carbonyl groups, and in particularly aldehyde groups, and also amido, carbonylic, carboxylic, nitrilic, hydroxylic, acetic, amino, and other functional groups. In the second step, the graft-copolymer is treated with formaldehyde, phenol, phenol-formaldehyde, or a mixture thereof, at elevated temperatures. The obtained modified lignin product is used to produce lignin phenol-formaldehyde resins. These resins can be used as binders in oriented strand board (OSB), particleboard, plywood, and other wood composite products and in industrial resins for electronics, automobiles, appliances, metal castings, abrasives, insulation, refractories and other applications.
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